WorldWideScience

Sample records for unusual statistical properties

  1. Computer predictions on Rh-based double perovskites with unusual electronic and magnetic properties

    Science.gov (United States)

    Halder, Anita; Nafday, Dhani; Sanyal, Prabuddha; Saha-Dasgupta, Tanusri

    2018-03-01

    In search for new magnetic materials, we make computer prediction of structural, electronic and magnetic properties of yet-to-be synthesized Rh-based double perovskite compounds, Sr(Ca)2BRhO6 (B=Cr, Mn, Fe). We use combination of evolutionary algorithm, density functional theory, and statistical-mechanical tool for this purpose. We find that the unusual valence of Rh5+ may be stabilized in these compounds through formation of oxygen ligand hole. Interestingly, while the Cr-Rh and Mn-Rh compounds are predicted to be ferromagnetic half-metals, the Fe-Rh compounds are found to be rare examples of antiferromagnetic and metallic transition-metal oxide with three-dimensional electronic structure. The computed magnetic transition temperatures of the predicted compounds, obtained from finite temperature Monte Carlo study of the first principles-derived model Hamiltonian, are found to be reasonably high. The prediction of favorable growth condition of the compounds, reported in our study, obtained through extensive thermodynamic analysis should be useful for future synthesize of this interesting class of materials with intriguing properties.

  2. Radiation heredity: unusual structural-phase states and metallic crystals properties

    International Nuclear Information System (INIS)

    Melikhov, V.D.; Skakov, M.K.

    1998-01-01

    Some experimental results allowing to judge about possibilities of unusual structural phase states formation during use irradiation and high temperature treatment of metallic crystals are considered. During study of pure (99.99 %) and especially pure (99.999 %) aluminium it was established, that after heating of preliminary irradiated samples in reactor, and non-irradiated ones up to temperatures above melting point (660 deg C), but not higher than 820 deg C, and cooling an microstructure and substructure of both irradiated and non-irradiated metals have been essentially distinguished with each other. If first of them had typically polycrystal construction, that second one was monocrystal with good developed initial substructure. Radiation effects have been preserved even in liquid metal if it was not overheated higher critical point, which is determined by phase transition from quasi-liquid state to true liquid one. During study of irradiation and postradiation treatment of structure and properties of intermetallides Fe 3 Al it was revealed, that in initially irradiated regulated alloys the radiation effect is preserving at heating of above 0.85 T melt (that essentially exceed order-disorder transition temperature) (550 deg C) in non-irradiated alloys of prolonged exposure and hardening. At that, irradiated-hardened alloy distinguishing from not hardened one by lattice parameter (on 0.1 %), by configuration of nearest surrounding of iron atoms in elementary cell, by regulating extent of different kind of atoms in lattice knocks. It was revealed, that at fluence (5·10 24 n·m 2 ) an appearance of new phases, distinguishing from matrix by component content. It was shown, that irradiation and post-radiation treatment are methods for creation unusual structural-phase states and attach to metals and alloys new properties

  3. Unusual photoluminescence properties of vertically aligned InN nanorods grown by plasma-assisted molecular-beam epitaxy

    International Nuclear Information System (INIS)

    Shen, C.H.; Chen, H.Y.; Lin, H.W.; Wu, C.Y.; Gwo, S.; Klochikhin, A.A.; Davydov, V.Yu.

    2007-01-01

    We report the unusual photoluminescence (PL) properties of vertically aligned InN nanorod arrays grown on Si(111) with a Si 3 N 4 buffer layer. The optimum growth conditions of InN nanorods are obtained by controlling the III/V ratio and the growth temperature. Structural characterization by X-ray diffraction and scanning electron microscopy indicates that individual nanorods are wurtzite InN single crystals with the growth direction along the c-axis. Near-infrared PL from InN nanorods is clearly observed at room temperature. However, in comparison to the PL from InN epitaxial films, the PL from InN nanorods is significantly lower in efficiency and exhibit anomalous temperature dependence. We propose that these unusual PL properties are results of considerable structural disorder (especially for the low-temperature grown InN nanorods) and strong surface electron accumulation effect. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  4. Statistical properties of reactor antineutrinos

    CERN Document Server

    Rusov, V D; Tarasov, V O; Shaaban, Y

    2002-01-01

    Based on the properties of the cascade statistics of reactor antineutrinos, the efficient method of searching for neutrino oscillations is offered. The determination of physical parameters of this statistics, i.e. the average number of fissions and the overage number of antineutrinos per fission, requires no a priori knowledge of the geometry and characteristics of the detector, the reactor power, and composition of nuclear fuel.

  5. Photophysical properties of coumarin-120: Unusual behavior in nonpolar solvents

    International Nuclear Information System (INIS)

    Pal, Haridas; Nad, Sanjukta; Kumbhakar, Manoj

    2003-01-01

    Photophysical properties of coumarin-120 (C120; 7-amino-4-methyl-1,2-benzopyrone) dye have been investigated in different solvents using steady-state and time-resolved fluorescence and picosecond laser flash photolysis (LFP) and nanosecond pulse radiolysis (PR) techniques. C120 shows unusual photophysical properties in nonpolar solvents compared to those in other solvents of moderate to higher polarities. Where the Stokes shifts (Δν-bar=ν-bar abs -ν-bar fl ), fluorescence quantum yields (Φ f ), and fluorescence lifetimes (τ f ) show more or less linear correlation with the solvent polarity function Δf={(ε-1)/(2ε+1)-(n 2 -1)/(2n 2 +1)}, all these parameters are unusually lower in nonpolar solvents. Unlike in other solvents, both Φ f and τ f in nonpolar solvents are also strongly temperature dependent. It is indicated that the excited singlet (S 1 ) state of C120 undergoes a fast activation-controlled nonradiative deexcitation in nonpolar solvents, which is absent in all other solvents. LFP and PR studies indicate that the intersystem crossing process is negligible for the present dye in all the solvents studied. Photophysical behavior of C120 in nonpolar solvent has been rationalized assuming that in these solvents the dye exists in a nonpolar structure, with its 7-NH 2 group in a pyramidal configuration. In this structure, since the 7-NH 2 group is bonded to the 1,2-benzopyrone moiety by a single bond, the former group can undergo a fast flip-flop motion, which in effect causes the fast nonradiative deexcitation of the dye excited state. In moderate to higher polarity solvents, it is indicated that the dye exists in an intramolecular charge-transfer structure, where the bond between 7-NH 2 group and the 1,2-benzopyrone moiety attains substantial double bond character. In this structure, the flip-flop motion of the 7-NH 2 group is highly restricted and thus there is no fast nonradiative deexcitation process for the excited dye

  6. Statistical Methods for Unusual Count Data

    DEFF Research Database (Denmark)

    Guthrie, Katherine A.; Gammill, Hilary S.; Kamper-Jørgensen, Mads

    2016-01-01

    microchimerism data present challenges for statistical analysis, including a skewed distribution, excess zero values, and occasional large values. Methods for comparing microchimerism levels across groups while controlling for covariates are not well established. We compared statistical models for quantitative...... microchimerism values, applied to simulated data sets and 2 observed data sets, to make recommendations for analytic practice. Modeling the level of quantitative microchimerism as a rate via Poisson or negative binomial model with the rate of detection defined as a count of microchimerism genome equivalents per...

  7. Multivariate statistical assessment of coal properties

    Czech Academy of Sciences Publication Activity Database

    Klika, Z.; Serenčíšová, J.; Kožušníková, Alena; Kolomazník, I.; Študentová, S.; Vontorová, J.

    2014-01-01

    Roč. 128, č. 128 (2014), s. 119-127 ISSN 0378-3820 R&D Projects: GA MŠk ED2.1.00/03.0082 Institutional support: RVO:68145535 Keywords : coal properties * structural,chemical and petrographical properties * multivariate statistics Subject RIV: DH - Mining, incl. Coal Mining Impact factor: 3.352, year: 2014 http://dx.doi.org/10.1016/j.fuproc.2014.06.029

  8. Distributional Properties of Order Statistics and Record Statistics

    Directory of Open Access Journals (Sweden)

    Abdul Hamid Khan

    2012-07-01

    Full Text Available Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman","serif";} Distributional properties of the order statistics, upper and lower records have been utilized to characterize distributions of interest. Further, one sided random dilation and contraction are utilized to obtain the distribution of non-adjacent ordered statistics and also their important deductions are discussed.

  9. Statistical properties of earthquakes clustering

    Directory of Open Access Journals (Sweden)

    A. Vecchio

    2008-04-01

    Full Text Available Often in nature the temporal distribution of inhomogeneous stochastic point processes can be modeled as a realization of renewal Poisson processes with a variable rate. Here we investigate one of the classical examples, namely, the temporal distribution of earthquakes. We show that this process strongly departs from a Poisson statistics for both catalogue and sequence data sets. This indicate the presence of correlations in the system probably related to the stressing perturbation characterizing the seismicity in the area under analysis. As shown by this analysis, the catalogues, at variance with sequences, show common statistical properties.

  10. On the statistical properties of photons

    International Nuclear Information System (INIS)

    Cini, M.

    1990-01-01

    The interpretation in terms of a transition from Maxwell-Boltzmann to Bose-Einstein statistics of the effect in quantum optics of degenerate light discovered by De Martini and Di Fonzo is discussed. It is shown that the results of the experiment can be explained by using only the quantum-mechanical rule that the states of an assembly of bosons should be completely symmetrical, without mentioning in any way their statistical properties. This means that photons are indeed identical particles

  11. Some Statistical Properties of Tonality, 1650-1900

    Science.gov (United States)

    White, Christopher Wm.

    2013-01-01

    This dissertation investigates the statistical properties present within corpora of common practice music, involving a data set of more than 8,000 works spanning from 1650 to 1900, and focusing specifically on the properties of the chord progressions contained therein. In the first chapter, methodologies concerning corpus analysis are presented…

  12. Rheological Characterization of Unusual DWPF Slurry Samples

    International Nuclear Information System (INIS)

    Koopman, D. C.

    2005-01-01

    A study was undertaken to identify and clarify examples of unusual rheological behavior in Defense Waste Processing Facility (DWPF) simulant slurry samples. Identification was accomplished by reviewing sludge, Sludge Receipt and Adjustment Tank (SRAT) product, and Slurry Mix Evaporator (SME) product simulant rheological results from the prior year. Clarification of unusual rheological behavior was achieved by developing and implementing new measurement techniques. Development of these new methods is covered in a separate report, WSRC-TR-2004-00334. This report includes a review of recent literature on unusual rheological behavior, followed by a summary of the rheological measurement results obtained on a set of unusual simulant samples. Shifts in rheological behavior of slurries as the wt. % total solids changed have been observed in numerous systems. The main finding of the experimental work was that the various unusual DWPF simulant slurry samples exhibit some degree of time dependent behavior. When a given shear rate is applied to a sample, the apparent viscosity of the slurry changes with time rather than remaining constant. These unusual simulant samples are more rheologically complex than Newtonian liquids or more simple slurries, neither of which shows significant time dependence. The study concludes that the unusual rheological behavior that has been observed is being caused by time dependent rheological properties in the slurries being measured. Most of the changes are due to the effect of time under shear, but SB3 SME products were also changing properties while stored in sample bottles. The most likely source of this shear-related time dependence for sludge is in the simulant preparation. More than a single source of time dependence was inferred for the simulant SME product slurries based on the range of phenomena observed. Rheological property changes were observed on the time-scale of a single measurement (minutes) as well as on a time scale of hours

  13. Statistical Properties of Online Auctions

    Science.gov (United States)

    Namazi, Alireza; Schadschneider, Andreas

    We characterize the statistical properties of a large number of online auctions run on eBay. Both stationary and dynamic properties, like distributions of prices, number of bids etc., as well as relations between these quantities are studied. The analysis of the data reveals surprisingly simple distributions and relations, typically of power-law form. Based on these findings we introduce a simple method to identify suspicious auctions that could be influenced by a form of fraud known as shill bidding. Furthermore the influence of bidding strategies is discussed. The results indicate that the observed behavior is related to a mixture of agents using a variety of strategies.

  14. Statistical properties of mine tremor aftershocks

    CSIR Research Space (South Africa)

    Kgarume, TE

    2010-02-01

    Full Text Available Mine tremors and their aftershocks pose a risk to mine workers in the deep gold mines of South Africa. The statistical properties of mine-tremor aftershocks were investigated as part of an endeavour to assess the hazard and manage the risk. Data...

  15. Study of statistical properties of hybrid statistic in coherent multi-detector compact binary coalescences Search

    OpenAIRE

    Haris, K; Pai, Archana

    2015-01-01

    In this article, we revisit the problem of coherent multi-detector search of gravitational wave from compact binary coalescence with Neutron stars and Black Holes using advanced interferometers like LIGO-Virgo. Based on the loss of optimal multi-detector signal-to-noise ratio (SNR), we construct a hybrid statistic as a best of maximum-likelihood-ratio(MLR) statistic tuned for face-on and face-off binaries. The statistical properties of the hybrid statistic is studied. The performance of this ...

  16. Some properties of point processes in statistical optics

    International Nuclear Information System (INIS)

    Picinbono, B.; Bendjaballah, C.

    2010-01-01

    The analysis of the statistical properties of the point process (PP) of photon detection times can be used to determine whether or not an optical field is classical, in the sense that its statistical description does not require the methods of quantum optics. This determination is, however, more difficult than ordinarily admitted and the first aim of this paper is to illustrate this point by using some results of the PP theory. For example, it is well known that the analysis of the photodetection of classical fields exhibits the so-called bunching effect. But this property alone cannot be used to decide the nature of a given optical field. Indeed, we have presented examples of point processes for which a bunching effect appears and yet they cannot be obtained from a classical field. These examples are illustrated by computer simulations. Similarly, it is often admitted that for fields with very low light intensity the bunching or antibunching can be described by using the statistical properties of the distance between successive events of the point process, which simplifies the experimental procedure. We have shown that, while this property is valid for classical PPs, it has no reason to be true for nonclassical PPs, and we have presented some examples of this situation also illustrated by computer simulations.

  17. Thermodynamics and statistical mechanics. [thermodynamic properties of gases

    Science.gov (United States)

    1976-01-01

    The basic thermodynamic properties of gases are reviewed and the relations between them are derived from the first and second laws. The elements of statistical mechanics are then formulated and the partition function is derived. The classical form of the partition function is used to obtain the Maxwell-Boltzmann distribution of kinetic energies in the gas phase and the equipartition of energy theorem is given in its most general form. The thermodynamic properties are all derived as functions of the partition function. Quantum statistics are reviewed briefly and the differences between the Boltzmann distribution function for classical particles and the Fermi-Dirac and Bose-Einstein distributions for quantum particles are discussed.

  18. Statistical properties of several models of fractional random point processes

    Science.gov (United States)

    Bendjaballah, C.

    2011-08-01

    Statistical properties of several models of fractional random point processes have been analyzed from the counting and time interval statistics points of view. Based on the criterion of the reduced variance, it is seen that such processes exhibit nonclassical properties. The conditions for these processes to be treated as conditional Poisson processes are examined. Numerical simulations illustrate part of the theoretical calculations.

  19. Statistical properties of superimposed stationary spike trains.

    Science.gov (United States)

    Deger, Moritz; Helias, Moritz; Boucsein, Clemens; Rotter, Stefan

    2012-06-01

    The Poisson process is an often employed model for the activity of neuronal populations. It is known, though, that superpositions of realistic, non- Poisson spike trains are not in general Poisson processes, not even for large numbers of superimposed processes. Here we construct superimposed spike trains from intracellular in vivo recordings from rat neocortex neurons and compare their statistics to specific point process models. The constructed superimposed spike trains reveal strong deviations from the Poisson model. We find that superpositions of model spike trains that take the effective refractoriness of the neurons into account yield a much better description. A minimal model of this kind is the Poisson process with dead-time (PPD). For this process, and for superpositions thereof, we obtain analytical expressions for some second-order statistical quantities-like the count variability, inter-spike interval (ISI) variability and ISI correlations-and demonstrate the match with the in vivo data. We conclude that effective refractoriness is the key property that shapes the statistical properties of the superposition spike trains. We present new, efficient algorithms to generate superpositions of PPDs and of gamma processes that can be used to provide more realistic background input in simulations of networks of spiking neurons. Using these generators, we show in simulations that neurons which receive superimposed spike trains as input are highly sensitive for the statistical effects induced by neuronal refractoriness.

  20. Statistical properties of transport in plasma turbulence

    DEFF Research Database (Denmark)

    Naulin, V.; Garcia, O.E.; Nielsen, A.H.

    2004-01-01

    The statistical properties of the particle flux in different types of plasma turbulence models are numerically investigated using probability distribution functions (PDFs). The physics included in the models range from two-dimensional drift wave turbulence to three-dimensional MHD dynamics...

  1. Statistics for Research

    CERN Document Server

    Dowdy, Shirley; Chilko, Daniel

    2011-01-01

    Praise for the Second Edition "Statistics for Research has other fine qualities besides superior organization. The examples and the statistical methods are laid out with unusual clarity by the simple device of using special formats for each. The book was written with great care and is extremely user-friendly."-The UMAP Journal Although the goals and procedures of statistical research have changed little since the Second Edition of Statistics for Research was published, the almost universal availability of personal computers and statistical computing application packages have made it possible f

  2. Image Statistics and the Representation of Material Properties in the Visual Cortex.

    Science.gov (United States)

    Baumgartner, Elisabeth; Gegenfurtner, Karl R

    2016-01-01

    We explored perceived material properties (roughness, texturedness, and hardness) with a novel approach that compares perception, image statistics and brain activation, as measured with fMRI. We initially asked participants to rate 84 material images with respect to the above mentioned properties, and then scanned 15 of the participants with fMRI while they viewed the material images. The images were analyzed with a set of image statistics capturing their spatial frequency and texture properties. Linear classifiers were then applied to the image statistics as well as the voxel patterns of visually responsive voxels and early visual areas to discriminate between images with high and low perceptual ratings. Roughness and texturedness could be classified above chance level based on image statistics. Roughness and texturedness could also be classified based on the brain activation patterns in visual cortex, whereas hardness could not. Importantly, the agreement in classification based on image statistics and brain activation was also above chance level. Our results show that information about visual material properties is to a large degree contained in low-level image statistics, and that these image statistics are also partially reflected in brain activity patterns induced by the perception of material images.

  3. Thermodynamic properties of particles with intermediate statistics

    International Nuclear Information System (INIS)

    Joyce, G.S.; Sarkar, S.; Spal/ek, J.; Byczuk, K.

    1996-01-01

    Analytic expressions for the distribution function of an ideal gas of particles (exclusons) which have statistics intermediate between Fermi-Dirac and Bose-Einstein are obtained for all values of the Haldane statistics parameter α element-of[0,1]. The analytic structure of the distribution function is investigated and found to have no singularities in the physical region when the parameter α lies in the range 0 V of the D-dimensional excluson gas. The low-temperature series for the thermodynamic properties illustrate the pseudofermion nature of exclusons. copyright 1996 The American Physical Society

  4. Statistical thermodynamics understanding the properties of macroscopic systems

    CERN Document Server

    Fai, Lukong Cornelius

    2012-01-01

    Basic Principles of Statistical PhysicsMicroscopic and Macroscopic Description of StatesBasic PostulatesGibbs Ergodic AssumptionGibbsian EnsemblesExperimental Basis of Statistical MechanicsDefinition of Expectation ValuesErgodic Principle and Expectation ValuesProperties of Distribution FunctionRelative Fluctuation of an Additive Macroscopic ParameterLiouville TheoremGibbs Microcanonical EnsembleMicrocanonical Distribution in Quantum MechanicsDensity MatrixDensity Matrix in Energy RepresentationEntropyThermodynamic FunctionsTemperatureAdiabatic ProcessesPressureThermodynamic IdentityLaws of Th

  5. Synthesis of ultrasmall Li-Mn spinel oxides exhibiting unusual ion exchange, electrochemical, and catalytic properties

    Science.gov (United States)

    Miyamoto, Yumi; Kuroda, Yoshiyuki; Uematsu, Tsubasa; Oshikawa, Hiroyuki; Shibata, Naoya; Ikuhara, Yuichi; Suzuki, Kosuke; Hibino, Mitsuhiro; Yamaguchi, Kazuya; Mizuno, Noritaka

    2015-10-01

    The efficient surface reaction and rapid ion diffusion of nanocrystalline metal oxides have prompted considerable research interest for the development of high functional materials. Herein, we present a novel low-temperature method to synthesize ultrasmall nanocrystalline spinel oxides by controlling the hydration of coexisting metal cations in an organic solvent. This method selectively led to Li-Mn spinel oxides by tuning the hydration of Li+ ions under mild reaction conditions (i.e., low temperature and short reaction time). These particles exhibited an ultrasmall crystallite size of 2.3 nm and a large specific surface area of 371 ± 15 m2 g-1. They exhibited unique properties such as unusual topotactic Li+/H+ ion exchange, high-rate discharge ability, and high catalytic performance for several aerobic oxidation reactions, by creating surface phenomena throughout the particles. These properties differed significantly from those of Li-Mn spinel oxides obtained by conventional solid-state methods.

  6. Synthesis of ultrasmall Li–Mn spinel oxides exhibiting unusual ion exchange, electrochemical, and catalytic properties

    Science.gov (United States)

    Miyamoto, Yumi; Kuroda, Yoshiyuki; Uematsu, Tsubasa; Oshikawa, Hiroyuki; Shibata, Naoya; Ikuhara, Yuichi; Suzuki, Kosuke; Hibino, Mitsuhiro; Yamaguchi, Kazuya; Mizuno, Noritaka

    2015-01-01

    The efficient surface reaction and rapid ion diffusion of nanocrystalline metal oxides have prompted considerable research interest for the development of high functional materials. Herein, we present a novel low-temperature method to synthesize ultrasmall nanocrystalline spinel oxides by controlling the hydration of coexisting metal cations in an organic solvent. This method selectively led to Li–Mn spinel oxides by tuning the hydration of Li+ ions under mild reaction conditions (i.e., low temperature and short reaction time). These particles exhibited an ultrasmall crystallite size of 2.3 nm and a large specific surface area of 371 ± 15 m2 g−1. They exhibited unique properties such as unusual topotactic Li+/H+ ion exchange, high-rate discharge ability, and high catalytic performance for several aerobic oxidation reactions, by creating surface phenomena throughout the particles. These properties differed significantly from those of Li–Mn spinel oxides obtained by conventional solid-state methods. PMID:26456216

  7. Doubly unusual 3D lattice honeycomb displaying simultaneous negative and zero Poisson’s ratio properties

    Science.gov (United States)

    Chen, Yu; Zheng, Bin-Bin; Fu, Ming-Hui; Lan, Lin-Hua; Zhang, Wen-Zhi

    2018-04-01

    In this paper, a novel three-dimensional (3D) lattice honeycomb is developed based on a two-dimensional (2D) accordion-like honeycomb. A combination of theoretical and numerical analysis is carried out to gain a deeper understanding of the elastic behavior of the new honeycomb and its dependence on the geometric parameters. The results show that the proposed new honeycomb can simultaneously achieve an in-plane negative Poisson’s ratio (NPR) effect and an out-of-plane zero Poisson’s ratio (ZPR) effect. This unique property may be very promising in some important fields, like aerospace, piezoelectric sensors and biomedicine engineering. The results also show that the geometric parameters, such as the slant angle, the strut thickness and the relative density, have a significant effect on the mechanical properties. Additionally, different dominant deformation models of the new honeycomb when compressed along the x (or y) and z directions are identified. This work provides a new concept for the design of honeycombs with a doubly unusual performance.

  8. Computer modelling of statistical properties of SASE FEL radiation

    International Nuclear Information System (INIS)

    Saldin, E. L.; Schneidmiller, E. A.; Yurkov, M. V.

    1997-01-01

    The paper describes an approach to computer modelling of statistical properties of the radiation from self amplified spontaneous emission free electron laser (SASE FEL). The present approach allows one to calculate the following statistical properties of the SASE FEL radiation: time and spectral field correlation functions, distribution of the fluctuations of the instantaneous radiation power, distribution of the energy in the electron bunch, distribution of the radiation energy after monochromator installed at the FEL amplifier exit and the radiation spectrum. All numerical results presented in the paper have been calculated for the 70 nm SASE FEL at the TESLA Test Facility being under construction at DESY

  9. Quantum mechanics of the fractional-statistics gas: Random-phase approximation

    International Nuclear Information System (INIS)

    Dai, Q.; Levy, J.L.; Fetter, A.L.; Hanna, C.B.; Laughlin, R.B.

    1992-01-01

    A description of the fractional-statistics gas based on the complete summation of Hartree, Fock, ladder and bubble diagrams is presented. The superfluid properties identified previously in the random-phase-approximation (RPA) calculation of Fetter, Hanna, and Laughlin [Phys. Rev. B 39, 9679 (1989)] are substantially confirmed. The discrepancy between the RPA sound speed and the Hartree-Fock bulk modulus is found to be eliminated. The unusual Hall-effect behavior is found to vanish for the Bose gas test case but not for the fractional-statistics gas, implying that it is physically correct. Excellent agreement is obtained with the collective-mode dispersion obtained numerically by Xie, He, and Das Sarma [Phys. Rev. Lett. 65, 649 (1990)

  10. Statistical properties of chaotic scattering with one open channel

    International Nuclear Information System (INIS)

    Izrajlev, F.M.; Saher, D.; Sokolov, V.V.

    1993-01-01

    The correspondence between statistical properties of decaying states and fluctuations in resonance scattering is studied in a statistical model with one open channel. The model is described by an ensemble of random nonhermitian matrices. The dependence of the correlation length on the coupling parameter both for the S-matrix and the cross-section is studied numerically. 37 refs., 7 figs

  11. Unusual clustering of coefficients of variation in published articles from a medical biochemistry department in India.

    Science.gov (United States)

    Hudes, Mark L; McCann, Joyce C; Ames, Bruce N

    2009-03-01

    A simple statistical method is described to test whether data are consistent with minimum statistical variability expected in a biological experiment. The method is applied to data presented in data tables in a subset of 84 articles among more than 200 published by 3 investigators in a small medical biochemistry department at a major university in India and to 29 "control" articles selected by key word PubMed searches. Major conclusions include: 1) unusual clustering of coefficients of variation (CVs) was observed for data from the majority of articles analyzed that were published by the 3 investigators from 2000-2007; unusual clustering was not observed for data from any of their articles examined that were published between 1992 and 1999; and 2) among a group of 29 control articles retrieved by PubMed key word, title, or title/abstract searches, unusually clustered CVs were observed in 3 articles. Two of these articles were coauthored by 1 of the 3 investigators, and 1 was from the same university but a different department. We are unable to offer a statistical or biological explanation for the unusual clustering observed.

  12. Scalar statistics in variable property turbulent channel flows

    NARCIS (Netherlands)

    Patel, A.; Boersma, B.J.; Pecnik, R.

    2017-01-01

    Direct numerical simulation of fully developed, internally heated channel flows with isothermal walls is performed using the low-Mach-number approximation of Navier-Stokes equation to investigate the influence of temperature-dependent properties on turbulent scalar statistics. Different constitutive

  13. Investigation of the statistical properties of light

    International Nuclear Information System (INIS)

    Jensen, A.S.

    1976-09-01

    The report describes the coherence properties and the statistical properties of light from a classical and quantum mechanical point of view. The theoretical part is used to describe some more specific examples within the field of light scattering such as light scattering from a collection of independent scatters, measurement of wind velocity, and single burst detection in a Laser-Doppler velocitimeter system where the description gives a figure of merit for such a system. An experimental investigation was made of Brillouin scattering in some organic liquids. The experimental equipment is described and the results reported. (Auth.)

  14. Average Nuclear properties based on statistical model

    International Nuclear Information System (INIS)

    El-Jaick, L.J.

    1974-01-01

    The rough properties of nuclei were investigated by statistical model, in systems with the same and different number of protons and neutrons, separately, considering the Coulomb energy in the last system. Some average nuclear properties were calculated based on the energy density of nuclear matter, from Weizsscker-Beth mass semiempiric formulae, generalized for compressible nuclei. In the study of a s surface energy coefficient, the great influence exercised by Coulomb energy and nuclear compressibility was verified. For a good adjust of beta stability lines and mass excess, the surface symmetry energy were established. (M.C.K.) [pt

  15. Numerical evaluation of the statistical properties of a potential energy landscape

    International Nuclear Information System (INIS)

    Nave, E La; Sciortino, F; Tartaglia, P; Michele, C De; Mossa, S

    2003-01-01

    The techniques which allow the numerical evaluation of the statistical properties of the potential energy landscape for models of simple liquids are reviewed and critically discussed. Expressions for the liquid free energy and its vibrational and configurational components are reported. Finally, a possible model for the statistical properties of the landscape, which appears to describe correctly fragile liquids in the region where equilibrium simulations are feasible, is discussed

  16. Statistical interior properties of globular proteins

    International Nuclear Information System (INIS)

    Zhou-Ting, Jiang; Tai-Quan, Wu; Lin-Xi, Zhang; Ting-Ting, Sun

    2009-01-01

    The character of forming long-range contacts affects the three-dimensional structure of globular proteins deeply. As the different ability to form long-range contacts between 20 types of amino acids and 4 categories of globular proteins, the statistical properties are thoroughly discussed in this paper. Two parameters N C and N D are defined to confine the valid residues in detail. The relationship between hydrophobicity scales and valid residue percentage of each amino acid is given in the present work and the linear functions are shown in our statistical results. It is concluded that the hydrophobicity scale defined by chemical derivatives of the amino acids and nonpolar phase of large unilamellar vesicle membranes is the most effective technique to characterise the hydrophobic behavior of amino acid residues. Meanwhile, residue percentage P i and sequential residue length L i of a certain protein i are calculated under different conditions. The statistical results show that the average value of P i as well as L i of all-α proteins has a minimum among these 4 classes of globular proteins, indicating that all-α proteins are hardly capable of forming long-range contacts one by one along their linear amino acid sequences. All-β proteins have a higher tendency to construct long-range contacts along their primary sequences related to the secondary configurations, i.e. parallel and anti-parallel configurations of β sheets. The investigation of the interior properties of globular proteins give us the connection between the three-dimensional structure and its primary sequence data or secondary configurations, and help us to understand the structure of protein and its folding process well. (cross-disciplinary physics and related areas of science and technology)

  17. Haldane's statistical interactions and universal properties of anyon systems

    International Nuclear Information System (INIS)

    Protogenov, A.

    1995-03-01

    The exclusion principle of fractional statistics proposed by Haldane is applied to systems with internal degrees of freedom. The symmetry of these systems is included in the statistical interaction matrix which contains the Cartan matrix of Lie algebras. The solutions of the equations for the statistical weights, which coincide with the thermodynamic Bethe ansatz equations are determined in the high temperature limit by the squares of q-deformed dimensions of irreducible representations. The entropy and other thermodynamic properties of anyon systems in this limit are completely characterized by the algebraic structure of symmetry in the universal form. (author). 39 refs

  18. Statistical data for the tensile properties of natural fibre composites

    Directory of Open Access Journals (Sweden)

    J.P. Torres

    2017-06-01

    Full Text Available This article features a large statistical database on the tensile properties of natural fibre reinforced composite laminates. The data presented here corresponds to a comprehensive experimental testing program of several composite systems including: different material constituents (epoxy and vinyl ester resins; flax, jute and carbon fibres, different fibre configurations (short-fibre mats, unidirectional, and plain, twill and satin woven fabrics and different fibre orientations (0°, 90°, and [0,90] angle plies. For each material, ~50 specimens were tested under uniaxial tensile loading. Here, we provide the complete set of stress–strain curves together with the statistical distributions of their calculated elastic modulus, strength and failure strain. The data is also provided as support material for the research article: “The mechanical properties of natural fibre composite laminates: A statistical study” [1].

  19. Unusual energy properties of leaky backward Lamb waves in a submerged plate.

    Science.gov (United States)

    Nedospasov, I A; Mozhaev, V G; Kuznetsova, I E

    2017-05-01

    It is found that leaky backward Lamb waves, i.e. waves with negative energy-flux velocity, propagating in a plate submerged in a liquid possess extraordinary energy properties distinguishing them from any other type of waves in isotropic media. Namely, the total time-averaged energy flux along the waveguide axis is equal to zero for these waves due to opposite directions of the longitudinal energy fluxes in the adjacent media. This property gives rise to the fundamental question of how to define and calculate correctly the energy velocity in such an unusual case. The procedure of calculation based on incomplete integration of the energy flux density over the plate thickness alone is applied. The derivative of the angular frequency with respect to the wave vector, usually referred to as the group velocity, happens to be close to the energy velocity defined by this mean in that part of the frequency range where the backward mode exists in the free plate. The existence region of the backward mode is formally increased for the submerged plate in comparison to the free plate as a result of the liquid-induced hybridization of propagating and nonpropagating (evanescent) Lamb modes. It is shown that the Rayleigh's principle (i.e. equipartition of total time-averaged kinetic and potential energies for time-harmonic acoustic fields) is violated due to the leakage of Lamb waves, in spite of considering nondissipative media. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Statistical properties of the nuclear shell-model Hamiltonian

    International Nuclear Information System (INIS)

    Dias, H.; Hussein, M.S.; Oliveira, N.A. de

    1986-01-01

    The statistical properties of realistic nuclear shell-model Hamiltonian are investigated in sd-shell nuclei. The probability distribution of the basic-vector amplitude is calculated and compared with the Porter-Thomas distribution. Relevance of the results to the calculation of the giant resonance mixing parameter is pointed out. (Author) [pt

  1. Statistical Properties of Gamma-Ray Burst Host Galaxies Jie-Min ...

    Indian Academy of Sciences (India)

    Statistical Properties of Gamma-Ray Burst Host Galaxies. Jie-Min Chen1, Jin Zhang2,3, ... of GRB host galaxies and explore possible correlations between these properties. We also investigate possible cosmic ... hydrogen column density for the GRB host galaxies in our sample. 6.295. The stellar masses are mainly in the ...

  2. Why do unusual novel foods like insects lack sensory appeal? Investigating the underlying sensory perceptions

    NARCIS (Netherlands)

    Tan Hui Shan, Grace; Tibboel, Claudia Joyce; Stieger, Markus

    2017-01-01

    Unusual novel foods like insects generally hold little sensory appeal for consumers, but little is known about the underlying sensory perceptions and how the properties of the food contribute to acceptance. This study examined the sensory perceptions of 3 unusual novel foods (lamb brain, frog

  3. Beauty in abstract paintings: Perceptual contrast and statistical properties

    Directory of Open Access Journals (Sweden)

    Birgit eMallon

    2014-03-01

    Full Text Available In this study, we combined the behavioral and objective approach in the field of empirical aesthetics. First, we studied the perception of beauty by investigating shifts in evaluation on perceived beauty of abstract artworks (Experiment 1. Because the participants showed heterogeneous individual preferences for the paintings, we divided them into seven clusters for the test. The experiment revealed a clear pattern of perceptual contrast. The perceived beauty of abstract paintings increased after exposure to paintings that were rated as less beautiful, and it decreased after exposure to paintings that were rated as more beautiful. Next, we searched for correlations of beauty ratings and perceptual contrast with statistical properties of abstract artworks (Experiment 2. The participants showed significant preferences for certain image properties. These preferences differed between the clusters of participants. Strikingly, next to color measures like hue, saturation, value and lightness, the recently described PHOG self-similarity value seems to be a predictor for aesthetic appreciation of abstract artworks. We speculate that the shift in evaluation in Experiment 1 was, at least in part, based on low-level adaptation to some of the statistical image properties analyzed in Experiment 2. In conclusion, our findings demonstrate that the perception of beauty in abstract artworks is altered after exposure to beautiful or non-beautiful images and correlates with particular image properties, especially color measures and self-similarity.

  4. STATISTICAL DISTRIBUTION PATTERNS IN MECHANICAL AND FATIGUE PROPERTIES OF METALLIC MATERIALS

    OpenAIRE

    Tatsuo, SAKAI; Masaki, NAKAJIMA; Keiro, TOKAJI; Norihiko, HASEGAWA; Department of Mechanical Engineering, Ritsumeikan University; Department of Mechanical Engineering, Toyota College of Technology; Department of Mechanical Engineering, Gifu University; Department of Mechanical Engineering, Gifu University

    1997-01-01

    Many papers on the statistical aspect of materials strength have been collected and reviewed by The Research Group for Statistical Aspects of Materials Strength.A book of "Statistical Aspects of Materials Strength" was written by this group, and published in 1992.Based on the experimental data compiled in this book, distribution patterns of mechanical properties are systematically surveyed paying an attention to metallic materials.Thus one can obtain the fundamental knowledge for a reliabilit...

  5. Characterizing the statistical properties of protein surfaces

    Science.gov (United States)

    Bak, Ji Hyun; Bitbol, Anne-Florence; Bialek, William

    Proteins and their interactions form the body of the signaling transduction pathway in many living systems. In order to ensure the accuracy as well as the specificity of signaling, it is crucial that proteins recognize their correct interaction partners. How difficult, then, is it for a protein to discriminate its correct interaction partner(s) from the possibly large set of other proteins it may encounter in the cell? An important ingredient of recognition is shape complementarity. The ensemble of protein shapes should be constrained by the need for maintaining functional interactions while avoiding spurious ones. To address this aspect of protein recognition, we consider the ensemble of proteins in terms of the shapes of their surfaces. We take into account the high-resolution structures of E.coli non-DNA-binding cytoplasmic proteins, retrieved from the Protein Data Bank. We aim to characterize the statistical properties of the protein surfaces at two levels: First, we study the intrinsic dimensionality at the level of the ensemble of the surface objects. Second, at the level of the individual surfaces, we determine the scale of shape variation. We further discuss how the dimensionality of the shape space is linked to the statistical properties of individual protein surfaces. Jhb and WB acknowledge support from National Science Foundation Grants PHY-1305525 and PHY-1521553. AFB acknowledges support from the Human Frontier Science Program.

  6. An unusual cosmological solution in the context of higher-derivative gravity

    International Nuclear Information System (INIS)

    Accioly, A.J.

    1988-01-01

    A general vacuum solution to the higher-derivative gravity field equations is presented in case of a model that exhibits symmetries of the Goedel-type. The solution possesses unusual properties. (author) [pt

  7. A Statistical and Wavelet Analysis of Physical Property Data From the 2950 m Deep Bellevue Borehole, Bushveld Complex, South Africa

    Science.gov (United States)

    Webb, S. J.; Ashwal, L. D.; Cooper, G. R.

    2007-12-01

    Susceptibility (n=~110,000) and density (n=~~2500) measurements on core samples have been collected in a stratigraphic context from the Bellevue (BV-1) 2950 m deep borehole in the Northern Lobe of the Bushveld Complex. This drill core starts in the granitoid roof rocks, extends through the entire Upper Zone, and ends approximately in the middle of the Main Zone. These physical property measurements now provide an extensive database useful for geophysical modeling and stratigraphic studies. In an effort to quantify the periodicity of the layering we have applied various statistical and wavelet methods to analyze the susceptibility and density data. The density data have revealed a strong periodic layering with a scale of ~~80 m that extends through the Main and Upper Zones. In the Main Zone the layering is unusual in that the density values increase upwards by as much as 10%. This is due to systematic variation in the modal abundance of mafic silicates and appears to be related to separate pulses during emplacement. The magnetic susceptibility data in the Upper Zone also show a strong cyclicity of similar scale. The discrete wavelet transform, using the real Haar wavelet, has been applied to help discretise the susceptibility data and clarifies the geological boundaries without blurring them, which is a common problem with multipoint moving averages. As expected, the histogram of the entire data set is non-Gaussian, with a long tail for high values. We can roughly fit a power law to the log histogram plot indicating a probable fractal distribution of susceptibilities. However if we window the data in the range 750-1000 m the histogram is very different. This region shows a strong peak and no power law relationship. This dramatic change in statistical properties prompted us to investigate these properties more thoroughly. To complement the wavelet analysis we have calculated various statistical measures (mean, standard deviation, skew, and

  8. Photon statistical properties of photon-added two-mode squeezed coherent states

    International Nuclear Information System (INIS)

    Xu Xue-Fen; Wang Shuai; Tang Bin

    2014-01-01

    We investigate photon statistical properties of the multiple-photon-added two-mode squeezed coherent states (PA-TMSCS). We find that the photon statistical properties are sensitive to the compound phase involved in the TMSCS. Our numerical analyses show that the photon addition can enhance the cross-correlation and anti-bunching effects of the PA-TMSCS. Compared with that of the TMSCS, the photon number distribution of the PA-TMSCS is modulated by a factor that is a monotonically increasing function of the numbers of adding photons to each mode; further, that the photon addition essentially shifts the photon number distribution. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

  9. Advanced statistical properties of dispersing billiards

    CERN Document Server

    Chernov, N

    2005-01-01

    A new approach to statistical properties of hyperbolic dynamical systems emerged recently; it was introduced by L.-S.~Young and modified by D.~Dolgopyat. It is based on coupling method borrowed from probability theory. We apply it here to one of the most physically interesting models -- Sinai billiards. It allows us to derive a series of new results, as well as make significant improvements in the existing results. First we establish sharp bounds on correlations (including multiple correlations). Then we use our correlation bounds to obtain the central limit theorem (CLT), the almost sure invariance principle (ASIP), the law of iterated logarithms, and integral tests.

  10. Beauty in abstract paintings: perceptual contrast and statistical properties

    Science.gov (United States)

    Mallon, Birgit; Redies, Christoph; Hayn-Leichsenring, Gregor U.

    2014-01-01

    In this study, we combined the behavioral and objective approach in the field of empirical aesthetics. First, we studied the perception of beauty by investigating shifts in evaluation on perceived beauty of abstract artworks (Experiment 1). Because the participants showed heterogeneous individual preferences for the paintings, we divided them into seven clusters for the test. The experiment revealed a clear pattern of perceptual contrast. The perceived beauty of abstract paintings increased after exposure to paintings that were rated as less beautiful, and it decreased after exposure to paintings that were rated as more beautiful. Next, we searched for correlations of beauty ratings and perceptual contrast with statistical properties of abstract artworks (Experiment 2). The participants showed significant preferences for particular image properties. These preferences differed between the clusters of participants. Strikingly, next to color measures like hue, saturation, value and lightness, the recently described Pyramid of Histograms of Orientation Gradients (PHOG) self-similarity value seems to be a predictor for aesthetic appreciation of abstract artworks. We speculate that the shift in evaluation in Experiment 1 was, at least in part, based on low-level adaptation to some of the statistical image properties analyzed in Experiment 2. In conclusion, our findings demonstrate that the perception of beauty in abstract artworks is altered after exposure to beautiful or non-beautiful images and correlates with particular image properties, especially color measures and self-similarity. PMID:24711791

  11. Extensive Air Showers with unusual structure

    Directory of Open Access Journals (Sweden)

    Beznosko Dmitriy

    2017-01-01

    Full Text Available A total of 23500 Extensive Air Showers (EAS with energies above ∼ 1016 eV have been detected during the ∼3500 hours of the Horizon-T (HT detectors system operations before Aug. 2016. Among these EAS, more than a thousand had an unusual spatial and temporary structure that showed pulses with several maxima (modals or modes from several detection points of the HT at the same time. These modes are separated in time from each other starting from tens to thousands of ns. These EAS have been called multi-modal. Analysis shows that the multi-modal EAS that have been detected by Horizon-T have the following properties: 1. Multi-modal EAS have energy above ∼1017 eV. 2. Pulses with several modes are located at large distances from the EAS axis. An overview of the collected data will be provided. General comments about the unusual structure of the multi-modal EAS will be presented.

  12. Quantitative study on the statistical properties of fibre architecture of genuine and numerical composite microstructures

    DEFF Research Database (Denmark)

    Hansen, Jens Zangenberg; Brøndsted, Povl

    2013-01-01

    A quantitative study is carried out regarding the statistical properties of the fibre architecture found in composite laminates and that generated numerically using Statistical Representative Volume Elements (SRVE’s). The aim is to determine the reliability and consistency of SRVE’s for represent......A quantitative study is carried out regarding the statistical properties of the fibre architecture found in composite laminates and that generated numerically using Statistical Representative Volume Elements (SRVE’s). The aim is to determine the reliability and consistency of SRVE...

  13. 41 CFR 101-39.206 - Seasonal or unusual requirements.

    Science.gov (United States)

    2010-07-01

    ... VEHICLES 39-INTERAGENCY FLEET MANAGEMENT SYSTEMS 39.2-GSA Interagency Fleet Management System Services... requirements for vehicles or related services shall inform the GSA IFMS fleet management center as far in... 41 Public Contracts and Property Management 2 2010-07-01 2010-07-01 true Seasonal or unusual...

  14. Statistical properties of antisymmetrized molecular dynamics for non-nucleon-emission and nucleon-emission processes

    International Nuclear Information System (INIS)

    Ono, A.; Horiuchi, H.

    1996-01-01

    Statistical properties of antisymmetrized molecular dynamics (AMD) are classical in the case of nucleon-emission processes, while they are quantum mechanical for the processes without nucleon emission. In order to understand this situation, we first clarify that there coexist mutually opposite two statistics in the AMD framework: One is the classical statistics of the motion of wave packet centroids and the other is the quantum statistics of the motion of wave packets which is described by the AMD wave function. We prove the classical statistics of wave packet centroids by using the framework of the microcanonical ensemble of the nuclear system with a realistic effective two-nucleon interaction. We show that the relation between the classical statistics of wave packet centroids and the quantum statistics of wave packets can be obtained by taking into account the effects of the wave packet spread. This relation clarifies how the quantum statistics of wave packets emerges from the classical statistics of wave packet centroids. It is emphasized that the temperature of the classical statistics of wave packet centroids is different from the temperature of the quantum statistics of wave packets. We then explain that the statistical properties of AMD for nucleon-emission processes are classical because nucleon-emission processes in AMD are described by the motion of wave packet centroids. We further show that when we improve the description of the nucleon-emission process so as to take into account the momentum fluctuation due to the wave packet spread, the AMD statistical properties for nucleon-emission processes change drastically into quantum statistics. Our study of nucleon-emission processes can be conversely regarded as giving another kind of proof of the fact that the statistics of wave packets is quantum mechanical while that of wave packet centroids is classical. copyright 1996 The American Physical Society

  15. Statistical and coherence properties of radiation from X-ray free electron lasers

    International Nuclear Information System (INIS)

    Saldin, E.L.; Schneidmiller, E.A.; Yurkov, M.V.

    2009-12-01

    We describe statistical and coherence properties of the radiation from X-ray free electron lasers (XFEL). It is shown that the X-ray FEL radiation before saturation is described with gaussian statistics. Particularly important is the case of the optimized X-ray FEL, studied in detail. Applying similarity techniques to the results of numerical simulations allowed us to find universal scaling relations for the main characteristics of an X-ray FEL operating in the saturation regime: efficiency, coherence time and degree of transverse coherence. We find that with an appropriate normalization of these quantities, they are functions of only the ratio of the geometrical emittance of the electron beam to the radiation wavelength. Statistical and coherence properties of the higher harmonics of the radiation are highlighted as well. (orig.)

  16. Statistical and coherence properties of radiation from X-ray free electron lasers

    Energy Technology Data Exchange (ETDEWEB)

    Saldin, E L; Schneidmiller, E A; Yurkov, M V

    2009-12-15

    We describe statistical and coherence properties of the radiation from X-ray free electron lasers (XFEL). It is shown that the X-ray FEL radiation before saturation is described with gaussian statistics. Particularly important is the case of the optimized X-ray FEL, studied in detail. Applying similarity techniques to the results of numerical simulations allowed us to find universal scaling relations for the main characteristics of an X-ray FEL operating in the saturation regime: efficiency, coherence time and degree of transverse coherence. We find that with an appropriate normalization of these quantities, they are functions of only the ratio of the geometrical emittance of the electron beam to the radiation wavelength. Statistical and coherence properties of the higher harmonics of the radiation are highlighted as well. (orig.)

  17. Statistical properties of laser light scattering in Brownian medium

    International Nuclear Information System (INIS)

    Suwono; Santoso, Budi; Baiquni, A.

    1983-01-01

    Relationship between statistical properties of laser light scattering in Brownian medium and photon-counting distributions are described in detail. A coherence optical detection has been constructed and by using photon-counting technique the ensemble distribution of the scattered field within space and time coherence has been measured. Good agreement between theory and experiment is shown. (author)

  18. Assessing attitudes towards statistics among medical students: psychometric properties of the Serbian version of the Survey of Attitudes Towards Statistics (SATS.

    Directory of Open Access Journals (Sweden)

    Dejana Stanisavljevic

    Full Text Available BACKGROUND: Medical statistics has become important and relevant for future doctors, enabling them to practice evidence based medicine. Recent studies report that students' attitudes towards statistics play an important role in their statistics achievements. The aim of the study was to test the psychometric properties of the Serbian version of the Survey of Attitudes Towards Statistics (SATS in order to acquire a valid instrument to measure attitudes inside the Serbian educational context. METHODS: The validation study was performed on a cohort of 417 medical students who were enrolled in an obligatory introductory statistics course. The SATS adaptation was based on an internationally accepted methodology for translation and cultural adaptation. Psychometric properties of the Serbian version of the SATS were analyzed through the examination of factorial structure and internal consistency. RESULTS: Most medical students held positive attitudes towards statistics. The average total SATS score was above neutral (4.3±0.8, and varied from 1.9 to 6.2. Confirmatory factor analysis validated the six-factor structure of the questionnaire (Affect, Cognitive Competence, Value, Difficulty, Interest and Effort. Values for fit indices TLI (0.940 and CFI (0.961 were above the cut-off of ≥0.90. The RMSEA value of 0.064 (0.051-0.078 was below the suggested value of ≤0.08. Cronbach's alpha of the entire scale was 0.90, indicating scale reliability. In a multivariate regression model, self-rating of ability in mathematics and current grade point average were significantly associated with the total SATS score after adjusting for age and gender. CONCLUSION: Present study provided the evidence for the appropriate metric properties of the Serbian version of SATS. Confirmatory factor analysis validated the six-factor structure of the scale. The SATS might be reliable and a valid instrument for identifying medical students' attitudes towards statistics in the

  19. Assessing attitudes towards statistics among medical students: psychometric properties of the Serbian version of the Survey of Attitudes Towards Statistics (SATS).

    Science.gov (United States)

    Stanisavljevic, Dejana; Trajkovic, Goran; Marinkovic, Jelena; Bukumiric, Zoran; Cirkovic, Andja; Milic, Natasa

    2014-01-01

    Medical statistics has become important and relevant for future doctors, enabling them to practice evidence based medicine. Recent studies report that students' attitudes towards statistics play an important role in their statistics achievements. The aim of the study was to test the psychometric properties of the Serbian version of the Survey of Attitudes Towards Statistics (SATS) in order to acquire a valid instrument to measure attitudes inside the Serbian educational context. The validation study was performed on a cohort of 417 medical students who were enrolled in an obligatory introductory statistics course. The SATS adaptation was based on an internationally accepted methodology for translation and cultural adaptation. Psychometric properties of the Serbian version of the SATS were analyzed through the examination of factorial structure and internal consistency. Most medical students held positive attitudes towards statistics. The average total SATS score was above neutral (4.3±0.8), and varied from 1.9 to 6.2. Confirmatory factor analysis validated the six-factor structure of the questionnaire (Affect, Cognitive Competence, Value, Difficulty, Interest and Effort). Values for fit indices TLI (0.940) and CFI (0.961) were above the cut-off of ≥0.90. The RMSEA value of 0.064 (0.051-0.078) was below the suggested value of ≤0.08. Cronbach's alpha of the entire scale was 0.90, indicating scale reliability. In a multivariate regression model, self-rating of ability in mathematics and current grade point average were significantly associated with the total SATS score after adjusting for age and gender. Present study provided the evidence for the appropriate metric properties of the Serbian version of SATS. Confirmatory factor analysis validated the six-factor structure of the scale. The SATS might be reliable and a valid instrument for identifying medical students' attitudes towards statistics in the Serbian educational context.

  20. Statistical properties of chaotic dynamical systems which exhibit strange attractors

    International Nuclear Information System (INIS)

    Jensen, R.V.; Oberman, C.R.

    1981-07-01

    A path integral method is developed for the calculation of the statistical properties of turbulent dynamical systems. The method is applicable to conservative systems which exhibit a transition to stochasticity as well as dissipative systems which exhibit strange attractors. A specific dissipative mapping is considered in detail which models the dynamics of a Brownian particle in a wave field with a broad frequency spectrum. Results are presented for the low order statistical moments for three turbulent regimes which exhibit strange attractors corresponding to strong, intermediate, and weak collisional damping

  1. Unusual features of proton and α-spectra from low-energy heavy-ion ...

    Indian Academy of Sciences (India)

    Home; Journals; Pramana – Journal of Physics; Volume 75; Issue 1. Unusual features ... Keywords. Proton and α-spectra; heavy-ion reaction; broad structures; nuclear level density. ... The broad structures in the -spectra cannot be fully explained within the statistical model even with the enhanced level density. In this case ...

  2. Far-IR Observations of Gas and Dust in the Unusual 49 Ceti Disk

    NARCIS (Netherlands)

    Roberge, Aki; Kamp, I.; Augereau, J.; Montesinos, B.; Meeus, G.; Olofsson, J.; Donaldson, J.; Howard, C. D.; Eiroa, C.; Dent, B.

    We present Herschel Space Observatory far-IR imaging and spectroscopy of 49 Cet, an unusual circumstellar disk around a nearby young A1V star. The system is famous for showing the dust properties of a debris disk, but the gas properties of a low-mass protoplanetary disk. Photometry was obtained at

  3. The statistical distribution of aerosol properties in sourthern West Africa

    Science.gov (United States)

    Haslett, Sophie; Taylor, Jonathan; Flynn, Michael; Bower, Keith; Dorsey, James; Crawford, Ian; Brito, Joel; Denjean, Cyrielle; Bourrianne, Thierry; Burnet, Frederic; Batenburg, Anneke; Schulz, Christiane; Schneider, Johannes; Borrmann, Stephan; Sauer, Daniel; Duplissy, Jonathan; Lee, James; Vaughan, Adam; Coe, Hugh

    2017-04-01

    The population and economy in southern West Africa have been growing at an exceptional rate in recent years and this trend is expected to continue, with the population projected to more than double to 800 million by 2050. This will result in a dramatic increase in anthropogenic pollutants, already estimated to have tripled between 1950 and 2000 (Lamarque et al., 2010). It is known that aerosols can modify the radiative properties of clouds. As such, the entrainment of anthropogenic aerosol into the large banks of clouds forming during the onset of the West African Monsoon could have a substantial impact on the region's response to climate change. Such projections, however, are greatly limited by the scarcity of observations in this part of the world. As part of the Dynamics-Aerosol-Chemistry-Cloud Interactions in West Africa (DACCIWA) project, three research aircraft were deployed, each carrying equipment capable of measuring aerosol properties in-situ. Instrumentation included Aerosol Mass Spectrometers (AMS), Single Particle Soot Photometers (SP2), Condensation Particle Counters (CPC) and Scanning Mobility Particle Sizers (SMPS). Throughout the intensive aircraft campaign, 155 hours of scientific flights covered an area including large parts of Benin, Togo, Ghana and parts of Côte D'Ivoire. Approximately 70 hours were dedicated to the measurement of cloud-aerosol interactions, with many other flights producing data contributing towards this objective. Using datasets collected during this campaign period, it is possible to build a robust statistical understanding of aerosol properties in this region for the first time, including size distributions and optical and chemical properties. Here, we describe preliminary results from aerosol measurements on board the three aircraft. These have been used to describe aerosol properties throughout the region and time period encompassed by the DACCIWA aircraft campaign. Such statistics will be invaluable for improving future

  4. Surface Properties of TNOs: Preliminary Statistical Analysis

    Science.gov (United States)

    Antonieta Barucci, Maria; Fornasier, S.; Alvarez-Cantal, A.; de Bergh, C.; Merlin, F.; DeMeo, F.; Dumas, C.

    2009-09-01

    An overview of the surface properties based on the last results obtained during the Large Program performed at ESO-VLT (2007-2008) will be presented. Simultaneous high quality visible and near-infrared spectroscopy and photometry have been carried out on 40 objects with various dynamical properties, using FORS1 (V), ISAAC (J) and SINFONI (H+K bands) mounted respectively at UT2, UT1 and UT4 VLT-ESO telescopes (Cerro Paranal, Chile). For spectroscopy we computed the spectral slope for each object and searched for possible rotational inhomogeneities. A few objects show features in their visible spectra such as Eris, whose spectral bands are displaced with respect to pure methane-ice. We identify new faint absorption features on 10199 Chariklo and 42355 Typhon, possibly due to the presence of aqueous altered materials. The H+K band spectroscopy was performed with the new instrument SINFONI which is a 3D integral field spectrometer. While some objects show no diagnostic spectral bands, others reveal surface deposits of ices of H2O, CH3OH, CH4, and N2. To investigate the surface properties of these bodies, a radiative transfer model has been applied to interpret the entire 0.4-2.4 micron spectral region. The diversity of the spectra suggests that these objects represent a substantial range of bulk compositions. These different surface compositions can be diagnostic of original compositional diversity, interior source and/or different evolution with different physical processes affecting the surfaces. A statistical analysis is in progress to investigate the correlation of the TNOs’ surface properties with size and dynamical properties.

  5. Statistical behavior of the tensile property of heated cotton fiber

    Science.gov (United States)

    The temperature dependence of the tensile property of single cotton fiber was studied in the range of 160-300°C using Favimat test, and its statistical behavior was interpreted in terms of structural changes. The tenacity of control cotton fiber was well described by the single Weibull distribution,...

  6. Statistical mechanics principles and selected applications

    CERN Document Server

    Hill, Terrell L

    1956-01-01

    ""Excellent … a welcome addition to the literature on the subject."" - ScienceBefore the publication of this standard, oft-cited book, there were few if any statistical-mechanics texts that incorporated reviews of both fundamental principles and recent developments in the field.In this volume, Professor Hill offers just such a dual presentation - a useful account of basic theory and of its applications, made accessible in a comprehensive format. The book opens with concise, unusually clear introductory chapters on classical statistical mechanics, quantum statistical mechanics and the relatio

  7. Herschel Observations of Gas and Dust in the Unusual 49 Ceti Debris Disk

    NARCIS (Netherlands)

    Roberge, A.; Kamp, I.; Montesinos, B.; Dent, W. R. F.; Meeus, G.; Donaldson, J. K.; Olofsson, J.; Moor, A.; Augereau, J. -C.; Howard, C.; Eiroa, C.; Thi, W. -F.; Ardila, D. R.; Sandell, G.; Woitke, P.

    2013-01-01

    We present far-IR/sub-mm imaging and spectroscopy of 49 Ceti, an unusual circumstellar disk around a nearby young A1V star. The system is famous for showing the dust properties of a debris disk, but the gas properties of a low-mass protoplanetary disk. The data were acquired with the Herschel Space

  8. Statistical Property and Model for the Inter-Event Time of Terrorism Attacks

    Science.gov (United States)

    Zhu, Jun-Fang; Han, Xiao-Pu; Wang, Bing-Hong

    2010-06-01

    The inter-event time of terrorism attack events is investigated by empirical data and model analysis. Empirical evidence shows that it follows a scale-free property. In order to understand the dynamic mechanism of such a statistical feature, an opinion dynamic model with a memory effect is proposed on a two-dimensional lattice network. The model mainly highlights the role of individual social conformity and self-affirmation psychology. An attack event occurs when the order parameter indicating the strength of public opposition opinion is smaller than a critical value. Ultimately, the model can reproduce the same statistical property as the empirical data and gives a good understanding for the possible dynamic mechanism of terrorism attacks.

  9. Statistical properties of anti-symmetrized molecular dynamics

    International Nuclear Information System (INIS)

    Ohnishi, A.; Randrup, J.

    1993-01-01

    We study the statistical equilibrium properties of the recently developed anti-symmetrized molecular dynamics model for heavy-ion reactions. We consider A non-interacting fermions in one dimension, either bound in a common harmonic potential or moving freely within an interval, and perform a Metropolis sampling of the corresponding parameter space. Generally the average excitation and the specific heat, considered as functions of the imposed temperature, behave in a classical manner when the canonical weight is calculated in the mean-field approximation. However, it is possible to obtain results that are much closer to the quantal behavior by modifying the weight to take approximate account of the energy fluctuations within the individual wave packets. (orig.)

  10. Southeast Atlantic Cloud Properties in a Multivariate Statistical Model - How Relevant is Air Mass History for Local Cloud Properties?

    Science.gov (United States)

    Fuchs, Julia; Cermak, Jan; Andersen, Hendrik

    2017-04-01

    This study aims at untangling the impacts of external dynamics and local conditions on cloud properties in the Southeast Atlantic (SEA) by combining satellite and reanalysis data using multivariate statistics. The understanding of clouds and their determinants at different scales is important for constraining the Earth's radiative budget, and thus prominent in climate-system research. In this study, SEA stratocumulus cloud properties are observed not only as the result of local environmental conditions but also as affected by external dynamics and spatial origins of air masses entering the study area. In order to assess to what extent cloud properties are impacted by aerosol concentration, air mass history, and meteorology, a multivariate approach is conducted using satellite observations of aerosol and cloud properties (MODIS, SEVIRI), information on aerosol species composition (MACC) and meteorological context (ERA-Interim reanalysis). To account for the often-neglected but important role of air mass origin, information on air mass history based on HYSPLIT modeling is included in the statistical model. This multivariate approach is intended to lead to a better understanding of the physical processes behind observed stratocumulus cloud properties in the SEA.

  11. Colonization, resistance to bile, and virulence properties of Escherichia coli strains: Unusual characteristics associated with biliary tract diseases.

    Science.gov (United States)

    Razaghi, Maryam; Tajeddin, Elahe; Ganji, Leila; Alebouyeh, Masoud; Alizadeh, Amir Houshang Mohammad; Sadeghi, Amir; Zali, Mohammad Reza

    2017-10-01

    Escherichia coli is the species that is most frequently isolated from bile of patients with biliary tract diseases. This study was aimed to investigate any association between resistance and virulence properties of these isolates with occurrence of the diseases. A total of 102 bile samples were obtained from patients subjected to endoscopic retrograde cholangiopancreatography for different biliary diseases. Clinical data were collected and culture of the bile samples was done on selective media. Resistance of characterized Escherichia coli isolates to deoxycholate sodium (0-7%) and nineteen antibiotics was determined and PCR using 16 pairs of primers targeting stx1, stx2, exhA, eae, bfp, agg, pcvd432, lt, st, ipaH, pic, pet, ast, set, sen, and cdtB genes was done. Our results showed a statistically significant association between E. coli colonization and existence of common bile duct and gallbladder stones (p value 0.028). Out of the 22 E. coli strains (22/102) multidrug resistance phenotype was present in 95.45%. None of the strains belonged to common E. coli pathotypes. However, bfp + EhxA-hly, bfp + astA, bfp + EhxA-hly + pic, and EhxA-hly + pic + astA, bfp, and astA genotypes were detected in these strains. bfp (7/22, 31.8%) and astA (5/22, 22.7%) were among most frequent virulence factors in these strains. Results of this study showed significant association between colonization of E. coli and choledocholithiasis. Unusual existence of virulence gene combinations in these strains and their resistance to DOC and multiple classes of antibiotics could be considered as possible causes of their persistence in this harsh microenvironment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Ten Years of Cloud Properties from MODIS: Global Statistics and Use in Climate Model Evaluation

    Science.gov (United States)

    Platnick, Steven E.

    2011-01-01

    The NASA Moderate Resolution Imaging Spectroradiometer (MODIS), launched onboard the Terra and Aqua spacecrafts, began Earth observations on February 24, 2000 and June 24,2002, respectively. Among the algorithms developed and applied to this sensor, a suite of cloud products includes cloud masking/detection, cloud-top properties (temperature, pressure), and optical properties (optical thickness, effective particle radius, water path, and thermodynamic phase). All cloud algorithms underwent numerous changes and enhancements between for the latest Collection 5 production version; this process continues with the current Collection 6 development. We will show example MODIS Collection 5 cloud climatologies derived from global spatial . and temporal aggregations provided in the archived gridded Level-3 MODIS atmosphere team product (product names MOD08 and MYD08 for MODIS Terra and Aqua, respectively). Data sets in this Level-3 product include scalar statistics as well as 1- and 2-D histograms of many cloud properties, allowing for higher order information and correlation studies. In addition to these statistics, we will show trends and statistical significance in annual and seasonal means for a variety of the MODIS cloud properties, as well as the time required for detection given assumed trends. To assist in climate model evaluation, we have developed a MODIS cloud simulator with an accompanying netCDF file containing subsetted monthly Level-3 statistical data sets that correspond to the simulator output. Correlations of cloud properties with ENSO offer the potential to evaluate model cloud sensitivity; initial results will be discussed.

  13. Statistical properties of visible and infrared beams retroreflected through a turbulent atmosphere

    International Nuclear Information System (INIS)

    Slatkine, M.; Bensimon, D.; Englander, A.; Shtrikman, S.; Treves, D.

    1980-01-01

    Statistical properties of HeNe and CO 2 laser beams retroreflected through a turbulent atmosphere are investigated experimentally for round paths of 1 km and 12 km. Both heterodyne and direct detection are used

  14. Subjective Ratings of Beauty and Aesthetics: Correlations With Statistical Image Properties in Western Oil Paintings

    Science.gov (United States)

    Lehmann, Thomas; Redies, Christoph

    2017-01-01

    For centuries, oil paintings have been a major segment of the visual arts. The JenAesthetics data set consists of a large number of high-quality images of oil paintings of Western provenance from different art periods. With this database, we studied the relationship between objective image measures and subjective evaluations of the images, especially evaluations on aesthetics (defined as artistic value) and beauty (defined as individual liking). The objective measures represented low-level statistical image properties that have been associated with aesthetic value in previous research. Subjective rating scores on aesthetics and beauty correlated not only with each other but also with different combinations of the objective measures. Furthermore, we found that paintings from different art periods vary with regard to the objective measures, that is, they exhibit specific patterns of statistical image properties. In addition, clusters of participants preferred different combinations of these properties. In conclusion, the results of the present study provide evidence that statistical image properties vary between art periods and subject matters and, in addition, they correlate with the subjective evaluation of paintings by the participants. PMID:28694958

  15. Analysis of Spatiotemporal Statistical Properties of Rainfall in the Phoenix Metropolitan Area

    Science.gov (United States)

    Mascaro, G.

    2016-12-01

    The analysis of the rainfall statistical properties at multiple spatiotemporal scales is a necessary preliminary step to support modeling of urban hydrology, including flood prediction and simulation of impacts of land use changes. In this contribution, the rainfall statistical properties are analyzed in the Phoenix Metropolitan area and its surroundings ( 29600 km2) in Arizona using observations from 310 gauges of the Flood Control District of the Maricopa County network. Different techniques are applied to investigate the rainfall properties at temporal scales from 1 min to years and to quantify the associated spatial variability. Results reveal the following. The rainfall regime is characterized by high interannual variability, which is partially explained by teleconnections with El Niño Southern Oscillation, and marked seasonality, with two maxima in the monsoon season from July to September and in winter from November to March. Elevation has a significant control on seasonal rainfall accumulation, strength of thermal convective activity during the monsoon, and peak occurrence of the rainfall diurnal cycle present in summer. The spatial correlation of wintertime rainfall is high even at short aggregation times (cells).

  16. Unusual manifestations of secondary urothelial carcinoma

    Directory of Open Access Journals (Sweden)

    Chaohui Lisa Zhao

    2016-03-01

    Full Text Available High-grade papillary urothelial carcinoma regularly invades the bladder wall, adjacent prostate, seminal vesicles, ureters, vagina, rectum, retroperitoneum, and regional lymph nodes. In advanced stages, it may disseminate to the liver, lungs, and bone marrow. On rare occasions, unusual metastatic foci like skin have been reported. The incidence of urothelial carcinoma has increased with associated rise in variants of urothelial carcinoma and unusual metastatic foci. It is imperative that urologists and pathologists are aware of the unusual variants and unusual metastatic locations to expedite the diagnostic process. Hereby we report an unusual case of secondary involvement of spinal nerve by conventional urothelial carcinoma. Also a second case of rhabdoid variant of urothelial carcinoma showing synchronous involvement of bladder and subcutaneous tissue of upper extremity is presented.

  17. Unusual headache syndromes.

    Science.gov (United States)

    Queiroz, Luiz P

    2013-01-01

    Some headache syndromes have few cases reported in the literature. Their clinical characteristics, pathogenesis, and treatment may have not been completely defined. They may not actually be uncommon but rather under-recognized and/or underreported. A literature review of unusual headache syndromes, searching PubMed and ISI Web of Knowledge, was performed. After deciding which disorders to study, relevant publications in scientific journals, including original articles, reviews, meeting abstracts, and letters or correspondences to the editors were searched. This paper reviewed the clinical characteristics, the pathogenesis, the diagnosis, and the treatment of five interesting and unusual headache syndromes: exploding head syndrome, red ear syndrome, neck-tongue syndrome, nummular headache, and cardiac cephalgia. Recognizing some unusual headaches, either primary or secondary, may be a challenge for many non-headache specialist physicians. It is important to study them because the correct diagnosis may result in specific treatments that may improve the quality of life of these patients, and this can even be life saving. © 2013 American Headache Society.

  18. Fundamental statistical features and self-similar properties of tagged networks

    International Nuclear Information System (INIS)

    Palla, Gergely; Farkas, Illes J; Pollner, Peter; Vicsek, Tamas; Derenyi, Imre

    2008-01-01

    We investigate the fundamental statistical features of tagged (or annotated) networks having a rich variety of attributes associated with their nodes. Tags (attributes, annotations, properties, features, etc) provide essential information about the entity represented by a given node, thus, taking them into account represents a significant step towards a more complete description of the structure of large complex systems. Our main goal here is to uncover the relations between the statistical properties of the node tags and those of the graph topology. In order to better characterize the networks with tagged nodes, we introduce a number of new notions, including tag-assortativity (relating link probability to node similarity), and new quantities, such as node uniqueness (measuring how rarely the tags of a node occur in the network) and tag-assortativity exponent. We apply our approach to three large networks representing very different domains of complex systems. A number of the tag related quantities display analogous behaviour (e.g. the networks we studied are tag-assortative, indicating possible universal aspects of tags versus topology), while some other features, such as the distribution of the node uniqueness, show variability from network to network allowing for pin-pointing large scale specific features of real-world complex networks. We also find that for each network the topology and the tag distribution are scale invariant, and this self-similar property of the networks can be well characterized by the tag-assortativity exponent, which is specific to each system.

  19. Artificial urinary sphincter erosion: the role of corticosteroids in an unusual presentation

    OpenAIRE

    Yap, Stanley A.; Stone, Anthony R.

    2010-01-01

    Glucocorticosteroid use has proven beneficial for the management of many medical conditions. Unfortunately its anti-inflammatory properties also profoundly affect many aspects of wound healing. We present a case of an unusual presentation of an artificial urinary sphincter erosion in a patient treated with chronic high-dose steroids.

  20. Movement and respiration detection using statistical properties of the FMCW radar signal

    KAUST Repository

    Kiuru, Tero; Metso, Mikko; Jardak, Seifallah; Pursula, Pekka; Hakli, Janne; Hirvonen, Mervi; Sepponen, Raimo

    2016-01-01

    This paper presents a 24 GHz FMCW radar system for detection of movement and respiration using change in the statistical properties of the received radar signal, both amplitude and phase. We present the hardware and software segments of the radar

  1. 48 CFR 32.114 - Unusual contract financing.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Unusual contract financing... CONTRACTING REQUIREMENTS CONTRACT FINANCING Non-Commercial Item Purchase Financing 32.114 Unusual contract financing. Any contract financing arrangement that deviates from this part is unusual contract financing...

  2. Movement and respiration detection using statistical properties of the FMCW radar signal

    KAUST Repository

    Kiuru, Tero

    2016-07-26

    This paper presents a 24 GHz FMCW radar system for detection of movement and respiration using change in the statistical properties of the received radar signal, both amplitude and phase. We present the hardware and software segments of the radar system as well as algorithms with measurement results for two distinct use-cases: 1. FMCW radar as a respiration monitor and 2. a dual-use of the same radar system for smart lighting and intrusion detection. By using change in statistical properties of the signal for detection, several system parameters can be relaxed, including, for example, pulse repetition rate, power consumption, computational load, processor speed, and memory space. We will also demonstrate, that the capability to switch between received signal strength and phase difference enables dual-use cases with one requiring extreme sensitivity to movement and the other robustness against small sources of interference. © 2016 IEEE.

  3. 48 CFR 432.114 - Unusual contract financing.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 4 2010-10-01 2010-10-01 false Unusual contract financing... CONTRACTING REQUIREMENTS CONTRACT FINANCING Non-Commercial Item Purchase Financing 432.114 Unusual contract financing. The HCA is authorized to approve unusual contract financing. The signed determination and finding...

  4. 48 CFR 1332.114 - Unusual contract financing.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Unusual contract financing... CONTRACTING REQUIREMENTS CONTRACT FINANCING Non-Commercial Item Purchase Financing 1332.114 Unusual contract financing. The designee authorized to approve unusual contract financing arrangements is set forth in CAM...

  5. Forecasting the student–professor matches that result in unusually effective teaching

    Science.gov (United States)

    Gross, Jennifer; Lakey, Brian; Lucas, Jessica L; LaCross, Ryan; R Plotkowski, Andrea; Winegard, Bo

    2015-01-01

    Background Two important influences on students' evaluations of teaching are relationship and professor effects. Relationship effects reflect unique matches between students and professors such that some professors are unusually effective for some students, but not for others. Professor effects reflect inter-rater agreement that some professors are more effective than others, on average across students. Aims We attempted to forecast students' evaluations of live lectures from brief, video-recorded teaching trailers. Sample Participants were 145 college students (74% female) enrolled in introductory psychology courses at a public university in the Great Lakes region of the United States. Methods Students viewed trailers early in the semester and attended live lectures months later. Because subgroups of students viewed the same professors, statistical analyses could isolate professor and relationship effects. Results Evaluations were influenced strongly by relationship and professor effects, and students' evaluations of live lectures could be forecasted from students' evaluations of teaching trailers. That is, we could forecast the individual students who would respond unusually well to a specific professor (relationship effects). We could also forecast which professors elicited better evaluations in live lectures, on average across students (professor effects). Professors who elicited unusually good evaluations in some students also elicited better memory for lectures in those students. Conclusions It appears possible to forecast relationship and professor effects on teaching evaluations by presenting brief teaching trailers to students. Thus, it might be possible to develop online recommender systems to help match students and professors so that unusually effective teaching emerges. PMID:24953773

  6. A comparative analysis of the statistical properties of large mobile phone calling networks.

    Science.gov (United States)

    Li, Ming-Xia; Jiang, Zhi-Qiang; Xie, Wen-Jie; Miccichè, Salvatore; Tumminello, Michele; Zhou, Wei-Xing; Mantegna, Rosario N

    2014-05-30

    Mobile phone calling is one of the most widely used communication methods in modern society. The records of calls among mobile phone users provide us a valuable proxy for the understanding of human communication patterns embedded in social networks. Mobile phone users call each other forming a directed calling network. If only reciprocal calls are considered, we obtain an undirected mutual calling network. The preferential communication behavior between two connected users can be statistically tested and it results in two Bonferroni networks with statistically validated edges. We perform a comparative analysis of the statistical properties of these four networks, which are constructed from the calling records of more than nine million individuals in Shanghai over a period of 110 days. We find that these networks share many common structural properties and also exhibit idiosyncratic features when compared with previously studied large mobile calling networks. The empirical findings provide us an intriguing picture of a representative large social network that might shed new lights on the modelling of large social networks.

  7. Statistical properties of trading activity in Chinese stock market

    Science.gov (United States)

    Sun, Xiaoqian; Cheng, Xueqi; Shen, Huawei; Wang, Zhaoyang

    2010-08-01

    We investigate the statistical properties of traders' trading behavior using cumulative distribution function(CDF). We analyze exchange data of 52 stocks for one-year period which contains non-manipulated stocks and manipulated stocks published by China Securities Regulatory Commission(CSRC). By analyzing the total number of transactions and the trading volume of each trader over a year, we find the cumulative distributions have power-law tails and the distributions between non-manipulated stocks and manipulated stocks are different. These findings can help us to detect the manipulated stocks.

  8. Vortex phase-induced changes of the statistical properties of a partially coherent radially polarized beam.

    Science.gov (United States)

    Guo, Lina; Chen, Yahong; Liu, Xianlong; Liu, Lin; Cai, Yangjian

    2016-06-27

    Partially coherent radially polarized (PCRP) beam was introduced and generated in recent years. In this paper, we investigate the statistical properties of a PCRP beam embedded with a vortex phase (i.e., PCRP vortex beam). We derive the analytical formula for the cross-spectral density matrix of a PCRP vortex beam propagating through a paraxial ABCD optical system and analyze the statistical properties of a PCRP vortex beam focused by a thin lens. It is found that the statistical properties of a PCRP vortex beam on propagation are much different from those of a PCRP beam. The vortex phase induces not only the rotation of the beam spot, but also the changes of the beam shape, the degree of polarization and the state of polarization. We also find that the vortex phase plays a role of resisting the coherence-induced degradation of the intensity distribution and the coherence-induced depolarization. Furthermore, we report experimental generation of a PCRP vortex beam for the first time. Our results will be useful for trapping and rotating particles, free-space optical communications and detection of phase object.

  9. Statistical Analysis of Spectral Properties and Prosodic Parameters of Emotional Speech

    Science.gov (United States)

    Přibil, J.; Přibilová, A.

    2009-01-01

    The paper addresses reflection of microintonation and spectral properties in male and female acted emotional speech. Microintonation component of speech melody is analyzed regarding its spectral and statistical parameters. According to psychological research of emotional speech, different emotions are accompanied by different spectral noise. We control its amount by spectral flatness according to which the high frequency noise is mixed in voiced frames during cepstral speech synthesis. Our experiments are aimed at statistical analysis of cepstral coefficient values and ranges of spectral flatness in three emotions (joy, sadness, anger), and a neutral state for comparison. Calculated histograms of spectral flatness distribution are visually compared and modelled by Gamma probability distribution. Histograms of cepstral coefficient distribution are evaluated and compared using skewness and kurtosis. Achieved statistical results show good correlation comparing male and female voices for all emotional states portrayed by several Czech and Slovak professional actors.

  10. Statistical properties of turbulent transport and fluctuations in tokamak and stellarator devices

    Energy Technology Data Exchange (ETDEWEB)

    Hidalgo, C; Pedrosa, M A; Milligen, B Van; Sanchez, E; Balbin, R; Garcia-Cortes, I [Euratom-CIEMAT Association, Madrid (Spain); Bleuel, J; Giannone, L.; Niedermeyer, H [Euratom-IPP Association, Garching (Germany)

    1997-05-01

    The statistical properties of fluctuations and turbulent transport have been studied in the plasma boundary region of stellarator (TJ-IU, W7-AS) and tokamak (TJ-I) devices. The local flux probability distribution function shows the bursty character of the flux and presents a systematic change as a function of the radial location. There exist large amplitude transport bursts that account for a significant part of the total flux. There is a strong similarity between the statistical properties of the turbulent fluxes in different devices. The value of the radial coherence associated with fluctuations and turbulent transport is strongly intermittent. This result emphasizes the importance of measurements with time resolution in understanding the interplay between the edge and the core regions in the plasma. For measurements in the plasma edge region of the TJ-IU torsatron, the turbulent flux does not, in general, show a larger radial coherence than the one associated with the fluctuations. (author). 14 refs, 6 figs.

  11. Statistical Image Properties in Large Subsets of Traditional Art, Bad Art, and Abstract Art.

    Science.gov (United States)

    Redies, Christoph; Brachmann, Anselm

    2017-01-01

    Several statistical image properties have been associated with large subsets of traditional visual artworks. Here, we investigate some of these properties in three categories of art that differ in artistic claim and prestige: (1) Traditional art of different cultural origin from established museums and art collections (oil paintings and graphic art of Western provenance, Islamic book illustration and Chinese paintings), (2) Bad Art from two museums that collect contemporary artworks of lesser importance (© Museum Of Bad Art [MOBA], Somerville, and Official Bad Art Museum of Art [OBAMA], Seattle), and (3) twentieth century abstract art of Western provenance from two prestigious museums (Tate Gallery and Kunstsammlung Nordrhein-Westfalen). We measured the following four statistical image properties: the fractal dimension (a measure relating to subjective complexity); self-similarity (a measure of how much the sections of an image resemble the image as a whole), 1st-order entropy of edge orientations (a measure of how uniformly different orientations are represented in an image); and 2nd-order entropy of edge orientations (a measure of how independent edge orientations are across an image). As shown previously, traditional artworks of different styles share similar values for these measures. The values for Bad Art and twentieth century abstract art show a considerable overlap with those of traditional art, but we also identified numerous examples of Bad Art and abstract art that deviate from traditional art. By measuring statistical image properties, we quantify such differences in image composition for the first time.

  12. Statistical analysis of coding for molecular properties in the olfactory bulb

    Directory of Open Access Journals (Sweden)

    Benjamin eAuffarth

    2011-07-01

    Full Text Available The relationship between molecular properties of odorants and neural activities is arguably one of the most important issues in olfaction and the rules governing this relationship are still not clear. In the olfactory bulb (OB, glomeruli relay olfactory information to second-order neurons which in turn project to cortical areas. We investigate relevance of odorant properties, spatial localization of glomerular coding sites, and size of coding zones in a dataset of 2-deoxyglucose images of glomeruli over the entire OB of the rat. We relate molecular properties to activation of glomeruli in the OB using a nonparametric statistical test and a support-vector machine classification study. Our method permits to systematically map the topographic representation of various classes of odorants in the OB. Our results suggest many localized coding sites for particular molecular properties and some molecular properties that could form the basis for a spatial map of olfactory information. We found that alkynes, alkanes, alkenes, and amines affect activation maps very strongly as compared to other properties and that amines, sulfur-containing compounds, and alkynes have small zones and high relevance to activation changes, while aromatics, alkanes, and carboxylics acid recruit very big zones in the dataset. Results suggest a local spatial encoding for molecular properties.

  13. Statistical Determination of Impact of Property Attributes for Weak Measurement Scales

    Directory of Open Access Journals (Sweden)

    Doszyń Mariusz

    2017-12-01

    Full Text Available Many of the property attributes are measured on weak scales (nominal and ordinal scale. For example, land allocation in the development plan is measured on a nominal scale and such categories as proximity, equipment, access to means of communication, location, and soil and water conditions, are measured on an ordinal scale. The use of statistical measures appropriate for interval or quotient scales is wrong in such cases. Therefore, the article presents statistical measures that allow specifying the impact of the attributes on real estate prices, which can be used for the weaker scales, mainly for the ordinal scale. In the empirical illustration the proposed measures will be calculated by using the actual database of transaction prices.

  14. Statistical properties of barium stars

    International Nuclear Information System (INIS)

    Hakkila, J.E.

    1986-01-01

    Barium stars are G- and K-giant stars with atmospheric excesses of s-process elements, and a broadband spectral depression in the blue portion of the spectrum. The strength of the λ4554 Ball line is used as a classification parameter known as the Barium Intensity. They have a mean absolute magnitude of 1.0 and a dispersion of 1.2 magnitudes (assuming a Gaussian distribution in absolute magnitude) as measured from secular and statistical parallaxes. These stars apparently belong to a young-disk population from analyses of both the solar reflex motion and their residual velocity distribution, which implies that they have an upper mass limit of around three solar masses. There is no apparent correlation of barium intensity with either luminosity or kinematic properties. The barium stars appear to be preferentially distributed in the direction of the local spiral arm, but show no preference to associate with or avoid the direction of the galactic center. They do not appear related to either the carbon or S-stars because of these tendencies and because of the stellar population to which each type of star belongs. The distribution in absolute magnitude combined with star count analyses implies that these stars are slightly less numerous than previously believed. Barium stars show infrared excesses that correlate with their barium intensities

  15. Evaluation of mechanical properties of steel wire ropes by statistical methods

    Directory of Open Access Journals (Sweden)

    Boroška Ján

    1999-12-01

    Full Text Available The contribution deals with the evaluation of mechanical properties of steel wire ropes using statistical methods from the viewpoint of the quality of single wires as well as the internal construction of the wire ropes. The evaluation is based on the loading capacity calculated from the strength, number of folds and torsions. For the better ilustration, a box plot has been constructed.

  16. Statistical properties of dynamical systems – Simulation and abstract computation

    International Nuclear Information System (INIS)

    Galatolo, Stefano; Hoyrup, Mathieu; Rojas, Cristóbal

    2012-01-01

    Highlights: ► A survey on results about computation and computability on the statistical properties of dynamical systems. ► Computability and non-computability results for invariant measures. ► A short proof for the computability of the convergence speed of ergodic averages. ► A kind of “constructive” version of the pointwise ergodic theorem. - Abstract: We survey an area of recent development, relating dynamics to theoretical computer science. We discuss some aspects of the theoretical simulation and computation of the long term behavior of dynamical systems. We will focus on the statistical limiting behavior and invariant measures. We present a general method allowing the algorithmic approximation at any given accuracy of invariant measures. The method can be applied in many interesting cases, as we shall explain. On the other hand, we exhibit some examples where the algorithmic approximation of invariant measures is not possible. We also explain how it is possible to compute the speed of convergence of ergodic averages (when the system is known exactly) and how this entails the computation of arbitrarily good approximations of points of the space having typical statistical behaviour (a sort of constructive version of the pointwise ergodic theorem).

  17. On the statistical properties and tail risk of violent conflicts

    Science.gov (United States)

    Cirillo, Pasquale; Taleb, Nassim Nicholas

    2016-06-01

    We examine statistical pictures of violent conflicts over the last 2000 years, providing techniques for dealing with the unreliability of historical data. We make use of a novel approach to deal with fat-tailed random variables with a remote but nonetheless finite upper bound, by defining a corresponding unbounded dual distribution (given that potential war casualties are bounded by the world population). This approach can also be applied to other fields of science where power laws play a role in modeling, like geology, hydrology, statistical physics and finance. We apply methods from extreme value theory on the dual distribution and derive its tail properties. The dual method allows us to calculate the real tail mean of war casualties, which proves to be considerably larger than the corresponding sample mean for large thresholds, meaning severe underestimation of the tail risks of conflicts from naive observation. We analyze the robustness of our results to errors in historical reports. We study inter-arrival times between tail events and find that no particular trend can be asserted. All the statistical pictures obtained are at variance with the prevailing claims about ;long peace;, namely that violence has been declining over time.

  18. Comparing Data Sets: Implicit Summaries of the Statistical Properties of Number Sets

    Science.gov (United States)

    Morris, Bradley J.; Masnick, Amy M.

    2015-01-01

    Comparing datasets, that is, sets of numbers in context, is a critical skill in higher order cognition. Although much is known about how people compare single numbers, little is known about how number sets are represented and compared. We investigated how subjects compared datasets that varied in their statistical properties, including ratio of…

  19. Analysis of statistical properties of laser speckles, forming in skin and mucous of colon: potential application in laser surgery

    Science.gov (United States)

    Rubtsov, Vladimir; Kapralov, Sergey; Chalyk, Iuri; Ulianova, Onega; Ulyanov, Sergey

    2013-02-01

    Statistical properties of laser speckles, formed in skin and mucous of colon have been analyzed and compared. It has been demonstrated that first and second order statistics of "skin" speckles and "mucous" speckles are quite different. It is shown that speckles, formed in mucous, are not Gaussian one. Layered structure of colon mucous causes formation of speckled biospeckles. First- and second- order statistics of speckled speckles have been reviewed in this paper. Statistical properties of Fresnel and Fraunhofer doubly scattered and cascade speckles are described. Non-gaussian statistics of biospeckles may lead to high localization of intensity of coherent light in human tissue during the laser surgery. Way of suppression of highly localized non-gaussian speckles is suggested.

  20. The unusual properties of beryllium surfaces

    International Nuclear Information System (INIS)

    Stumpf, R.; Hannon, J.B.

    1994-01-01

    Be is a ''marginal metal.'' The stable phase, hcp-Be, has a low Fermi-level density of states and very anisotropic structural and elastic properties, similar to a semiconductor's. At the Be(0001) surface, surface states drastically increase the Fermi-level density of states. The different nature of bonding in bulk-Be and at the Be(0001) surface explains the large outward relaxation. The presence of surface states causes large surface core-level shifts by inducing a higher electrostatic potential in the surface layers and by improving the screening at the surface. The authors experimental and theoretical investigations of atomic vibrations at the Be(0001) surface demonstrate clearly that Be screening of atomic motion by the surface states makes the surface phonon dispersion fundamentally different from that of the bulk. Properties of Be(0001) are so different from those of the bulk that the surface can be considered a new ''phase'' of beryllium with unique electronic and structural characteristics. For comparison they also study Be(11 bar 20), a very open surface without important surface states. Be(11 bar 20) is the only clean s-p metal surface known to reconstruct (1 x 3 missing row reconstruction)

  1. A Statistics-Based Material Property Analysis to Support TPS Characterization

    Science.gov (United States)

    Copeland, Sean R.; Cozmuta, Ioana; Alonso, Juan J.

    2012-01-01

    Accurate characterization of entry capsule heat shield material properties is a critical component in modeling and simulating Thermal Protection System (TPS) response in a prescribed aerothermal environment. The thermal decomposition of the TPS material during the pyrolysis and charring processes is poorly characterized and typically results in large uncertainties in material properties as inputs for ablation models. These material property uncertainties contribute to large design margins on flight systems and cloud re- construction efforts for data collected during flight and ground testing, making revision to existing models for entry systems more challenging. The analysis presented in this work quantifies how material property uncertainties propagate through an ablation model and guides an experimental test regimen aimed at reducing these uncertainties and characterizing the dependencies between properties in the virgin and charred states for a Phenolic Impregnated Carbon Ablator (PICA) based TPS. A sensitivity analysis identifies how the high-fidelity model behaves in the expected flight environment, while a Monte Carlo based uncertainty propagation strategy is used to quantify the expected spread in the in-depth temperature response of the TPS. An examination of how perturbations to the input probability density functions affect output temperature statistics is accomplished using a Kriging response surface of the high-fidelity model. Simulations are based on capsule configuration and aerothermal environments expected during the Mars Science Laboratory (MSL) entry sequence. We identify and rank primary sources of uncertainty from material properties in a flight-relevant environment, show the dependence on spatial orientation and in-depth location on those uncertainty contributors, and quantify how sensitive the expected results are.

  2. Statistical properties of multi-theta polymer chains

    Science.gov (United States)

    Uehara, Erica; Deguchi, Tetsuo

    2018-04-01

    We study statistical properties of polymer chains with complex structures whose chemical connectivities are expressed by graphs. The multi-theta curve of m subchains with two branch points connected by them is one of the simplest graphs among those graphs having closed paths, i.e. loops. We denoted it by θm , and for m  =  2 it is given by a ring. We derive analytically the pair distribution function and the scattering function for the θm -shaped polymer chains consisting of m Gaussian random walks of n steps. Surprisingly, it is shown rigorously that the mean-square radius of gyration for the Gaussian θm -shaped polymer chain does not depend on the number m of subchains if each subchain has the same fixed number of steps. For m  =  3 we show the Kratky plot for the theta-shaped polymer chain consisting of hard cylindrical segments by the Monte-Carlo method including reflection at trivalent vertices.

  3. Chemical composition of HAL, an isotopically-unusual Allende inclusion

    International Nuclear Information System (INIS)

    Davis, A.M.; Tanaka, T.; Grossman, L.; Lee, T.; Wasserburg, G.J.

    1982-01-01

    Thirty-seven major, minor and trace elements were determined by INAA and RNAA in samples of hibonite, black rim and portions of friable rim from an unusual Allende inclusion, HAL. The peculiar isotopic, mineralogical and textural properties of HAL are accompanied by very unusual trace element abundances. The most striking feature of the chemistry is the virtual absence of Ce from an inclusion otherwise highly enriched in REE compared to C1 chondrites. HAL is also depleted in Sr, Ba, U, V, Ru, Os and Ir, relative to other refractory elements. Of the lithophile elements determined which are normally considered to be refractory in a gas of solar composition, Sr, Ba, Ce, U and V are the most volatile in oxidizing gases. The distribution of REE between hibonite and rims seems to have been established when hibonite and other refractory minerals were removed at slightly different temperatures from a hot, oxidizing gas in which they previously coexisted as separate grains. On the basis of HAL's chemical and isotopic composition, possible locations for the chemical and mass dependent isotopic fractionation are discussed. (author)

  4. Unusual CoS2 ellipsoids with anisotropic tube-like cavities and their application in supercapacitors.

    Science.gov (United States)

    Zhang, Lei; Wu, Hao Bin; Lou, Xiong Wen

    2012-07-14

    Unusual CoS(2) ellipsoids with anisotropic tube-like cavities have been synthesized from the simultaneous thermal decomposition and sulfidation of a preformed cobalt carbonate precursor. The as-prepared CoS(2) ellipsoids show interesting supercapacitive properties with high capacitance and good cycling performance.

  5. Dynamical topology and statistical properties of spatiotemporal chaos.

    Science.gov (United States)

    Zhuang, Quntao; Gao, Xun; Ouyang, Qi; Wang, Hongli

    2012-12-01

    For spatiotemporal chaos described by partial differential equations, there are generally locations where the dynamical variable achieves its local extremum or where the time partial derivative of the variable vanishes instantaneously. To a large extent, the location and movement of these topologically special points determine the qualitative structure of the disordered states. We analyze numerically statistical properties of the topologically special points in one-dimensional spatiotemporal chaos. The probability distribution functions for the number of point, the lifespan, and the distance covered during their lifetime are obtained from numerical simulations. Mathematically, we establish a probabilistic model to describe the dynamics of these topologically special points. In spite of the different definitions in different spatiotemporal chaos, the dynamics of these special points can be described in a uniform approach.

  6. STATISTICAL PROPERTIES OF GALACTIC δ SCUTI STARS: REVISITED

    International Nuclear Information System (INIS)

    Chang, S.-W.; Kim, D.-W.; Byun, Y.-I.; Protopapas, P.

    2013-01-01

    We present statistical characteristics of 1578 δ Scuti stars including nearby field stars and cluster member stars within the Milky Way. We obtained 46% of these stars (718 stars) from work by Rodríguez and collected the remaining 54% of stars (860 stars) from other literature. We updated the entries with the latest information of sky coordinates, color, rotational velocity, spectral type, period, amplitude, and binarity. The majority of our sample is well characterized in terms of typical period range (0.02-0.25 days), pulsation amplitudes (<0.5 mag), and spectral types (A-F type). Given this list of δ Scuti stars, we examined relations between their physical properties (i.e., periods, amplitudes, spectral types, and rotational velocities) for field stars and cluster members, and confirmed that the correlations of properties are not significantly different from those reported in Rodríguez's work. All the δ Scuti stars are cross-matched with several X-ray and UV catalogs, resulting in 27 X-ray and 41 UV-only counterparts. These counterparts are interesting targets for further study because of their uniqueness in showing δ Scuti-type variability and X-ray/UV emission at the same time. The compiled catalog can be accessed through the Web interface http://stardb.yonsei.ac.kr/DeltaScuti.

  7. Sum rule approach to the study of statistical decay properties of nuclear giant resonances

    International Nuclear Information System (INIS)

    Adhikari, S.K.; Hussein, M.S.

    1987-03-01

    Corrections to the well-known statistical sum rule that relates the summed transmission coefficients on the one hand and 2πΓ C.N. .ρ C.N. On the other, in the context of the statistical decay properties of nuclear giant resonances, are discussed. These corrections arise both from pre-equilibrium processes as well as from the giant resonance itself. It is shown that the compound nucleus average width is reduced as a result of these corrections. (Author) [pt

  8. Statistical properties of entropy production derived from fluctuation theorems

    International Nuclear Information System (INIS)

    Merhav, Neri; Kafri, Yariv

    2010-01-01

    Several implications of well-known fluctuation theorems, on the statistical properties of entropy production, are studied using various approaches. We begin by deriving a tight lower bound on the variance of the entropy production for a given mean of this random variable. It is shown that the Evans–Searles fluctuation theorem alone imposes a significant lower bound on the variance only when the mean entropy production is very small. It is then nonetheless demonstrated that upon incorporating additional information concerning the entropy production, this lower bound can be significantly improved, so as to capture extensivity properties. Another important aspect of the fluctuation properties of the entropy production is the relationship between the mean and the variance, on the one hand, and the probability of the event where the entropy production is negative, on the other hand. Accordingly, we derive upper and lower bounds on this probability in terms of the mean and the variance. These bounds are tighter than previous bounds that can be found in the literature. Moreover, they are tight in the sense that there exist probability distributions, satisfying the Evans–Searles fluctuation theorem, that achieve them with equality. Finally, we present a general method for generating a wide class of inequalities that must be satisfied by the entropy production. We use this method to derive several new inequalities that go beyond the standard derivation of the second law

  9. Bohm's mysterious 'quantum force' and 'active information': alternative interpretation and statistical properties

    International Nuclear Information System (INIS)

    Lan, B.L.

    2001-01-01

    An alternative interpretation to Bohm's 'quantum force' and 'active information' is proposed. Numerical evidence is presented, which suggests that the time series of Bohm's 'quantum force' evaluated at the Bohmian position for non-stationary quantum states are typically non-Gaussian stable distributed with a flat power spectrum in classically chaotic Hamiltonian systems. An important implication of these statistical properties is briefly mentioned. (orig.)

  10. Facile synthesis of gold nanomaterials with unusual crystal structures.

    Science.gov (United States)

    Fan, Zhanxi; Huang, Xiao; Chen, Ye; Huang, Wei; Zhang, Hua

    2017-11-01

    Gold (Au) nanomaterials have attracted wide research attention, owing to their high chemical stability, promising catalytic properties, excellent biocompatibility, unique electronic structure and outstanding localized surface plasmon resonance (LSPR) absorption properties; all of which are closely related to their size and shape. Recently, crystal-phase-controlled synthesis of noble metal nanomaterials has emerged as a promising strategy to tune their physicochemical properties. This protocol describes the detailed experimental procedures for the crystal-phase-controlled syntheses of Au nanomaterials with unusual crystal structures under mild conditions. Briefly, pure hexagonal close-packed (hcp) Au square sheets (AuSSs) with a thickness of ∼2.4 nm are synthesized using a graphene-oxide-assisted method in which HAuCl 4 is reduced by oleylamine in a mixture of hexane and ethanol. By using pure hexane as the solvent, well-dispersed ultrathin hcp/face-centered cubic (fcc) Au nanowires with a diameter of ∼1.6 nm on graphene oxide can be obtained. Meanwhile, hcp/fcc Au square-like plates with a side length of 200-400 nm are prepared via the secondary growth of Au on the hcp AuSSs. Remarkably, hexagonal (4H) Au nanoribbons with a thickness of 2.0-6.0 nm can be synthesized with a one-pot colloidal method in which HAuCl 4 is reduced by oleylamine in a mixed solvent of hexane and 1,2-dichloropropane. It takes 17-37 h for the synthesis of these Au nanomaterials with unusual crystal structures. Transmission electron microscopy (TEM) and atomic force microscopy (AFM) are used to characterize the resultant Au nanomaterials, which could have many promising applications, such as biosensing, near-IR photothermal therapy, catalysis and surface-enhanced Raman scattering (SERS).

  11. In silico environmental chemical science: properties and processes from statistical and computational modelling

    Energy Technology Data Exchange (ETDEWEB)

    Tratnyek, P. G.; Bylaska, Eric J.; Weber, Eric J.

    2017-01-01

    Quantitative structure–activity relationships (QSARs) have long been used in the environmental sciences. More recently, molecular modeling and chemoinformatic methods have become widespread. These methods have the potential to expand and accelerate advances in environmental chemistry because they complement observational and experimental data with “in silico” results and analysis. The opportunities and challenges that arise at the intersection between statistical and theoretical in silico methods are most apparent in the context of properties that determine the environmental fate and effects of chemical contaminants (degradation rate constants, partition coefficients, toxicities, etc.). The main example of this is the calibration of QSARs using descriptor variable data calculated from molecular modeling, which can make QSARs more useful for predicting property data that are unavailable, but also can make them more powerful tools for diagnosis of fate determining pathways and mechanisms. Emerging opportunities for “in silico environmental chemical science” are to move beyond the calculation of specific chemical properties using statistical models and toward more fully in silico models, prediction of transformation pathways and products, incorporation of environmental factors into model predictions, integration of databases and predictive models into more comprehensive and efficient tools for exposure assessment, and extending the applicability of all the above from chemicals to biologicals and materials.

  12. In silico environmental chemical science: properties and processes from statistical and computational modelling.

    Science.gov (United States)

    Tratnyek, Paul G; Bylaska, Eric J; Weber, Eric J

    2017-03-22

    Quantitative structure-activity relationships (QSARs) have long been used in the environmental sciences. More recently, molecular modeling and chemoinformatic methods have become widespread. These methods have the potential to expand and accelerate advances in environmental chemistry because they complement observational and experimental data with "in silico" results and analysis. The opportunities and challenges that arise at the intersection between statistical and theoretical in silico methods are most apparent in the context of properties that determine the environmental fate and effects of chemical contaminants (degradation rate constants, partition coefficients, toxicities, etc.). The main example of this is the calibration of QSARs using descriptor variable data calculated from molecular modeling, which can make QSARs more useful for predicting property data that are unavailable, but also can make them more powerful tools for diagnosis of fate determining pathways and mechanisms. Emerging opportunities for "in silico environmental chemical science" are to move beyond the calculation of specific chemical properties using statistical models and toward more fully in silico models, prediction of transformation pathways and products, incorporation of environmental factors into model predictions, integration of databases and predictive models into more comprehensive and efficient tools for exposure assessment, and extending the applicability of all the above from chemicals to biologicals and materials.

  13. Towards a better understanding of the relationship between belief in the paranormal and statistical bias: The potential role of schizotypy

    Directory of Open Access Journals (Sweden)

    Neil Dagnall

    2016-07-01

    Full Text Available The present paper examined relationships between schizotypy (measured by the Oxford-Liverpool Inventory of Feelings and Experience; O-LIFE scale brief, belief in the paranormal (assessed via the Revised Paranormal Belief Scale; RPBS and proneness to statistical bias (i.e., perception of randomness and susceptibility to conjunction fallacy. Participants were 254 volunteers recruited via convenience sampling. Probabilistic reasoning problems appeared framed within both standard and paranormal contexts. Analysis revealed positive correlations between the Unusual Experience subscale of O-LIFE and paranormal belief measures (RPBS full scale, traditional paranormal beliefs and new age philosophy. Performance on standard problems correlated negatively with Unusual Experience and belief in the paranormal (particularly the traditional paranormal belief dimension of the RPBS. Consideration of specific problem types revealed that perception of randomness associated more strongly with belief in the paranormal than conjunction; both problem types related similarly to Unusual Experience. Structural equation modelling specified that belief in the paranormal mediated the indirect relationship between Unusual Experience and statistical bias. For problems presented in a paranormal context a framing effect occurred. Whilst Unusual Experience correlated positively with conjunction proneness (controlling for perception of randomness, there was no association between Unusual Experience and perception of randomness (controlling for conjunction.

  14. Volatility measurement with directional change in Chinese stock market: Statistical property and investment strategy

    Science.gov (United States)

    Ma, Junjun; Xiong, Xiong; He, Feng; Zhang, Wei

    2017-04-01

    The stock price fluctuation is studied in this paper with intrinsic time perspective. The event, directional change (DC) or overshoot, are considered as time scale of price time series. With this directional change law, its corresponding statistical properties and parameter estimation is tested in Chinese stock market. Furthermore, a directional change trading strategy is proposed for invest in the market portfolio in Chinese stock market, and both in-sample and out-of-sample performance are compared among the different method of model parameter estimation. We conclude that DC method can capture important fluctuations in Chinese stock market and gain profit due to the statistical property that average upturn overshoot size is bigger than average downturn directional change size. The optimal parameter of DC method is not fixed and we obtained 1.8% annual excess return with this DC-based trading strategy.

  15. Statistical properties of material strength for reliability evaluation of components of fast reactors. Austenitic stainless steels

    International Nuclear Information System (INIS)

    Takaya, Shigeru; Sasaki, Naoto; Tomobe, Masato

    2015-03-01

    Many efforts have been made to implement the System Based Code concept of which objective is to optimize margins dispersed in several codes and standards. Failure probability is expected to be a promising quantitative index for optimization of margins, and statistical information for random variables is needed to evaluate failure probability. Material strength like tensile strength is an important random variable, but the statistical information has not been provided enough yet. In this report, statistical properties of material strength such as creep rupture time, steady creep strain rate, yield stress, tensile stress, flow stress, fatigue life and cyclic stress-strain curve, were estimated for SUS304 and 316FR steel, which are typical structural materials for fast reactors. Other austenitic stainless steels like SUS316 were also used for statistical estimation of some material properties such as fatigue life. These materials are registered in the JSME code of design and construction of fast reactors, so test data used for developing the code were used as much as possible in this report. (author)

  16. Statistical evaluation of the mechanical properties of high-volume class F fly ash concretes

    KAUST Repository

    Yoon, Seyoon; Monteiro, Paulo J.M.; Macphee, Donald E.; Glasser, Fredrik P.; Imbabi, Mohammed Salah-Eldin

    2014-01-01

    the authors experimentally and statistically investigated the effects of mix-design factors on the mechanical properties of high-volume class F fly ash concretes. A total of 240 and 32 samples were produced and tested in the laboratory to measure compressive

  17. Statistical properties of cross-correlation in the Korean stock market

    Science.gov (United States)

    Oh, G.; Eom, C.; Wang, F.; Jung, W.-S.; Stanley, H. E.; Kim, S.

    2011-01-01

    We investigate the statistical properties of the cross-correlation matrix between individual stocks traded in the Korean stock market using the random matrix theory (RMT) and observe how these affect the portfolio weights in the Markowitz portfolio theory. We find that the distribution of the cross-correlation matrix is positively skewed and changes over time. We find that the eigenvalue distribution of original cross-correlation matrix deviates from the eigenvalues predicted by the RMT, and the largest eigenvalue is 52 times larger than the maximum value among the eigenvalues predicted by the RMT. The β_{473} coefficient, which reflect the largest eigenvalue property, is 0.8, while one of the eigenvalues in the RMT is approximately zero. Notably, we show that the entropy function E(σ) with the portfolio risk σ for the original and filtered cross-correlation matrices are consistent with a power-law function, E( σ) σ^{-γ}, with the exponent γ 2.92 and those for Asian currency crisis decreases significantly.

  18. Unusual Fears in Children with Autism

    Science.gov (United States)

    Mayes, Susan Dickerson; Calhoun, Susan L.; Aggarwal, Richa; Baker, Courtney; Mathapati, Santosh; Molitoris, Sarah; Mayes, Rebecca D.

    2013-01-01

    Unusual fears have long been recognized as common in autism, but little research exists. In our sample of 1033 children with autism, unusual fears were reported by parents of 421 (41%) of the children, representing 92 different fears. Many additional children had common childhood fears (e.g., dogs, bugs, and the dark). More than half of children…

  19. Statistical properties of country risk ratings under oil price volatility: Evidence from selected oil-exporting countries

    International Nuclear Information System (INIS)

    Liu, Chang; Sun, Xiaolei; Chen, Jianming; Li, Jianping

    2016-01-01

    This paper focuses on the application of panel models for identification and analysis of influence of oil price volatility on statistical properties of country risk ratings which stem from uncertainty of macroeconomic fluctuations. Firstly, two statistical properties of country risk ratings, volatility clustering and asymmetrical revision were identified in a theoretical framework based on Cruces (2006). Secondly, considering the oil price volatility, numerical experiments were conducted based on extended models to test and verify specific properties of country risk ratings in selected oil-exporting countries. Empirical results suggest that properties of country risk remain comparatively steady despite oil price volatility. It is also found that the oil price volatility can obviously exaggerate the country risk volatility, as it happened during 2007–2009. Country clustering based on the properties of country risk ratings shows that the selected countries maintain a significant clustering tendency. These features are of great importance for estimating risk exposure of international trade and investments in oil export during extreme situations. - Highlights: •Relationship between oil price volatility and country risk is the focus. •An extended model based on Cruces (2006) is proposed. •Volatility clustering and asymmetrical revision of country risk ratings is explored. •Oil price volatility can obviously exaggerate properties of country risk volatility.

  20. Unusual radiological findings of adult-onset pulmonary tuberculosis

    International Nuclear Information System (INIS)

    Lee, Yong Chul; Lee, Jong Beum; Kim, Sue Hyun

    1987-01-01

    Usual chest radiographic findings in pulmonary tuberculosis are well described in radiologic literatures for both primary and postprimary phases of disease. During the last decade, many authors have enumerated the unusual manifestations of pulmonary tuberculosis in adult population. These unusual findings usually have been involved in the frequent failure of both radiologist and clinician to recognize that tuberculosis could be the cause of a abnormal chest radiograph in patients who are finally and surprisingly proven to have tuberculosis. Authors have evaluated 249 patients who were admitted and newly proven to have adult-onset pulmonary tuberculosis at Chung-Ang University Hospital from January, 1985 to December, 1986. Unusual findings were noted in 76 (30.5%) of the 249 patients with adult-onset pulmonary tuberculosis. These unusual findings most frequently could be seen in 3rd decades and showed no sex difference in incidence. A broad spectrum of abnormal findings including usual and unusual abnormalities were procedure by adult-onset pulmonary tuberculosis. The unusual radiographic findings were arbitrarily classified. Pleural effusion without parenchymal disease (10.0%), unusual location of infiltrate (5.6%) and atelectasis (3.2%) were relatively common. Hilar and / or mediastinal lymphnode enlargement (1.6%), cavity without parenchymal infiltrates (1.6%), septic lung-like infiltrates (1.6%), completely clear lungs (1.2%), miliary infiltrates (1.2%), fibrocalcific scar-like infiltrates (1.2%), masslike density (1.2%) and rheumatoid lung-like infiltrates (1.2%) were occasionally noted. Pneumothorax without parenchymal disease (0.4%) and bron chocutaneous fistula (0.4%) are. The recognition of these unusual findings could further improve the detection and diagnosis of adult-onset pulmonary tuberculosis

  1. Myasthenia Gravis: Unusual Presentations and Diagnostic Pitfalls.

    Science.gov (United States)

    Rodolico, Carmelo; Parisi, Daniela; Portaro, Simona; Biasini, Fiammetta; Sinicropi, Stefano; Ciranni, Annamaria; Toscano, Antonio; Messina, Sonia; Musumeci, Olimpia; Vita, Giuseppe; Girlanda, Paolo

    2016-08-30

    Myasthenia gravis (MG) is an autoimmune disorder presenting with fluctuating, fatigable muscle weakness. Initial symptoms classically involve ocular and proximal limb muscles. Rarely, MG may onset with unusual features, so it can be misdiagnosed with other neuromuscular diseases. To describe unusual and atypical presentations of MG in a large cohort of patients, considering and discussing diagnostic difficulties and pitfalls. We report on 21 out of 508 MG patients, coming to our department in the last 27 years and presenting with atypical or unusual features. The diagnosis was achieved performing a careful clinical examination, a proper neurophysiological assessment, the neostigmine test, the AChR and MuSK antibodies assay and chest CT-scan. Patients with atypical/unusual MG onset were the 4.4% of all MG patients population. We describe seven different clinical categories: asymmetric distal upper limbs weakness, foot drop, isolated triceps brachii weakness and foot drop, post exertional axial weakness with dropped head, acute facial dyplegia, limb-girdle MG and MG with sudden lower limbs weakness and recurrent falls. Atypical and unusual presentations may increase the risk to misdiagnose or delay MG diagnosis. Isolated limb-girdle presentation is the most frequent atypical form in our series.

  2. Some properties of the statistical models of the spherical Friedman world

    International Nuclear Information System (INIS)

    Rumyantseva, E.N.

    1981-01-01

    Considered are some properties of the statistical model of the spherical Friedman world filled with quantum gas of massless particles the spin of which can be equal to 0, 1/2, 1. Obtained are approximate expressions for a number of particles of Fermi- and Bose-gas and for the radius of the world taking into account mainly the dependence on the spin. The dependence of the number of particles on the radius of the world and temperature of the gas is illustrated [ru

  3. Statistical properties of the anomalous scaling exponent estimator based on time-averaged mean-square displacement

    Science.gov (United States)

    Sikora, Grzegorz; Teuerle, Marek; Wyłomańska, Agnieszka; Grebenkov, Denis

    2017-08-01

    The most common way of estimating the anomalous scaling exponent from single-particle trajectories consists of a linear fit of the dependence of the time-averaged mean-square displacement on the lag time at the log-log scale. We investigate the statistical properties of this estimator in the case of fractional Brownian motion (FBM). We determine the mean value, the variance, and the distribution of the estimator. Our theoretical results are confirmed by Monte Carlo simulations. In the limit of long trajectories, the estimator is shown to be asymptotically unbiased, consistent, and with vanishing variance. These properties ensure an accurate estimation of the scaling exponent even from a single (long enough) trajectory. As a consequence, we prove that the usual way to estimate the diffusion exponent of FBM is correct from the statistical point of view. Moreover, the knowledge of the estimator distribution is the first step toward new statistical tests of FBM and toward a more reliable interpretation of the experimental histograms of scaling exponents in microbiology.

  4. Statistical properties of compartmental model parameters extracted from dynamic positron emission tomography experiments

    International Nuclear Information System (INIS)

    Mazoyer, B.M.; Huesman, R.H.; Budinger, T.F.; Knittel, B.L.

    1986-01-01

    Over the past years a major focus of research in physiologic studies employing tracers has been the computer implementation of mathematical methods of kinetic modeling for extracting the desired physiological parameters from tomographically derived data. A study is reported of factors that affect the statistical properties of compartmental model parameters extracted from dynamic positron emission tomography (PET) experiments

  5. DETAILED CHEMICAL ABUNDANCES OF FOUR STARS IN THE UNUSUAL GLOBULAR CLUSTER PALOMAR 1

    International Nuclear Information System (INIS)

    Sakari, Charli M.; Venn, Kim A.; Irwin, Mike; Aoki, Wako; Arimoto, Nobuo; Dotter, Aaron

    2011-01-01

    Detailed chemical abundances for 21 elements are presented for four red giants in the anomalous outer halo globular cluster Palomar 1 (R GC = 17.2 kpc, Z = 3.6 kpc) using high-resolution (R = 36, 000) spectra from the High Dispersion Spectrograph on the Subaru Telescope. Pal 1 has long been considered unusual because of its low surface brightness, sparse red giant branch, young age, and its possible association with two extragalactic streams of stars. This paper shows that its chemistry further confirms its unusual nature. The mean metallicity of the four stars, [Fe/H] = -0.60 ± 0.01, is high for a globular cluster so far from the Galactic center, but is low for a typical open cluster. The [α/Fe] ratios, though in agreement with the Galactic stars within the 1σ errors, agree best with the lower values in dwarf galaxies. No signs of the Na/O anticorrelation are detected in Pal 1, though Na appears to be marginally high in all four stars. Pal 1's neutron-capture elements are also unusual: its high [Ba/Y] ratio agrees best with dwarf galaxies, implying an excess of second-peak over first-peak s-process elements, while its [Eu/α] and [Ba/Eu] ratios show that Pal 1's contributions from the r-process must have differed in some way from normal Galactic stars. Therefore, Pal 1 is unusual chemically, as well in its other properties. Pal 1 shares some of its unusual abundance characteristics with the young clusters associated with the Sagittarius dwarf galaxy remnant and the intermediate-age LMC clusters, and could be chemically associated with the Canis Majoris overdensity; however, it does not seem to be similar to the Monoceros/Galactic Anticenter Stellar Stream.

  6. 48 CFR 632.114 - Unusual contract financing.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 4 2010-10-01 2010-10-01 false Unusual contract financing. 632.114 Section 632.114 Federal Acquisition Regulations System DEPARTMENT OF STATE GENERAL CONTRACTING REQUIREMENTS CONTRACT FINANCING Non-Commercial Item Purchase Financing 632.114 Unusual contract financing. The...

  7. 48 CFR 2432.114 - Unusual contract financing.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 6 2010-10-01 2010-10-01 true Unusual contract financing... DEVELOPMENT GENERAL CONTRACTING REQUIREMENTS CONTRACT FINANCING Non-Commercial Item Purchase Financing 2432.114 Unusual contract financing. The Senior Procurement Executive is the agency head for the purpose of...

  8. Improving EWMA Plans for Detecting Unusual Increases in Poisson Counts

    Directory of Open Access Journals (Sweden)

    R. S. Sparks

    2009-01-01

    adaptive exponentially weighted moving average (EWMA plan is developed for signalling unusually high incidence when monitoring a time series of nonhomogeneous daily disease counts. A Poisson transitional regression model is used to fit background/expected trend in counts and provides “one-day-ahead” forecasts of the next day's count. Departures of counts from their forecasts are monitored. The paper outlines an approach for improving early outbreak data signals by dynamically adjusting the exponential weights to be efficient at signalling local persistent high side changes. We emphasise outbreak signals in steady-state situations; that is, changes that occur after the EWMA statistic had run through several in-control counts.

  9. Unusual Physical Properties of the Chicxulub Crater Peak Ring: Results from IODP/ICDP Expedition 364

    Science.gov (United States)

    Christeson, G. L.; Gebhardt, C.; Gulick, S. P. S.; Le Ber, E.; Lofi, J.; Morgan, J. V.; Nixon, C.; Rae, A.; Schmitt, D. R.

    2017-12-01

    IODP/ICDP Expedition 364 Hole M0077A drilled into the peak ring of the Chicxulub impact crater, recovering core between 505.7 and 1334.7 m below the seafloor (mbsf). Physical property measurements include wireline logging data, a vertical seismic profile (VSP), Multi-Sensor Core Logger (MSCL) measurements, and discrete sample measurements. The Hole M0077A peak ring rocks have unusual physical properties. Across the boundary between post-impact sediment and crater breccia we measure a sharp decrease in velocities and densities, and an increase in porosity. Mean crater breccia values are 3000-3300 m/s, 2.14-2.15 g/cm3, and 31% for velocity, density, and porosity, respectively. This zone is also associated with a low-frequency reflector package on MCS profiles and a low-velocity layer in FWI images, both confirmed from the VSP dataset. The thin (24 m) crater melt unit has mean velocity measurements of 3800-4150 m/s, density measurements of 2.32-2.34 g/cm3, and porosity measurements of 20%; density and porosity values are intermediate between the overlying impact breccia and underlying granitic basement, while the velocity values are similar to those for the underlying basement. The Hole M0077A crater melt unit velocities and densities are considerably less than values of 5800 m/s and 2.68 g/cm3 measured at an onshore well located in the annular trough. The uplifted granitic peak ring materials have mean values of 4100-4200 m/s, 2.39-2.44 g/cm3, and 11% for compressional wave velocity, density, and porosity, respectively; these values differ significantly from typical granite which has higher velocities (5400-6000 m/s) and densities (2.62-2.67 g/cm3), and lower porosities (<1%). All Hole M0077A peak-ring velocity, density, and porosity measurements indicate considerable fracturing, and are consistent with numerical models for peak-ring formation.

  10. Crystalline α-Sm2S3 nanowires: Structure and optical properties of an unusual intrinsically degenerate semiconductor

    International Nuclear Information System (INIS)

    Marin, Chris M.; Wang, Lu; Brewer, Joseph R.; Mei, Wai-Ning; Cheung, Chin Li

    2013-01-01

    Highlights: ► Developed a rapid synthetic method to generate thin films of α-Sm 2 S 3 nanowires. ► Calculated the electronic structure of α-Sm 2 S 3 by density functional theory. ► Predicted that α-Sm 2 S 3 is an intrinsically degenerate p-type semiconductor. ► Found that the gap in the band states of α-Sm 2 S 3 could be engineered to 1.3 eV via sulfur vacancy. -- Abstract: The lanthanide sulfides have long been a promising class of semiconductors because of their infrared-to-visible range band gaps and excellent thermoelectric properties. However, their applications have been limited due to their time consuming conventional synthetic processes and the lack of sufficient understanding of their electronic properties. To address these shortcomings, here we report a rapid, chemical vapor deposition route which results in thin films of crystalline α-phase samarium sesquisulfide (α-Sm 2 S 3 ) nanowires within a few hours, rather than the typical 4–7 days required in previous synthetic processes. In addition, density functional theory was, for the first time, utilized to calculate the electronic band structure of α-Sm 2 S 3 in order to shed insight into the interpretation of their UV–Vis absorption spectrum. We found that the theoretical direct gap in the band states of α-Sm 2 S 3 is 1.7 eV. Computation results suggest that this gap can be tuned to a solar optimal ∼1.3 eV via systematic sulfur vacancy sites engineered into the crystal structure. Most significantly, the degenerate semiconductor-like behavior long observed in lanthanide sulfide samples have been shown to be present even in the ideal α-Sm 2 S 3 structure, suggesting that the observed heavily p-type behavior is an unusual intrinsic property of the material resulting from the Fermi level being located significantly below the optically active 1.7 eV band edge

  11. Perovskite BaBiO3 Transformed Layered BaBiO2.5 Crystals Featuring Unusual Chemical Bonding and Luminescence.

    Science.gov (United States)

    Li, Hong; Zhao, Qing; Liu, Bo-Mei; Zhang, Jun-Ying; Li, Zhi-Yong; Guo, Shao-Qiang; Ma, Ju-Ping; Kuroiwa, Yoshihiro; Moriyoshi, Chikako; Zheng, Li-Rong; Sun, Hong-Tao

    2018-04-14

    Engineering oxygen coordination environments of cations in oxides has received intense interest thanks to the opportunities for the discovery of novel oxides with unusual properties. Here we present the successful synthesis of stoichiometric layered BaBiO2.5 enabled by a non-topotactic phase transformation of perovskite BaBiO3. By analysing the synchrotron X-ray diffraction data using the maximum entropy method/Rietveld technique, we find that Bi forms unusual chemical bondings with four oxygen atoms, featuring one ionic bonding and three covalent bondings that results in an asymmetric coordination geometry. A broad range of photophysical characterizations reveal that this peculiar structure shows near-infrared luminescence differing from conventional Bi-bearing systems. Experimental and theoretical results lead us to propose the excitonic nature of luminescence. Our work highlights that synthesizing materials with uncommon Bi-O bonding and Bi coordination geometry provides a pathway to the discovery of systems with new functionalities. We envisage that this work could inspire interest for the exploration of a range of materials containing heavier p-block elements, offering prospects for the finding of systems with unusual properties. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Sub-Poissonian statistics in order-to-chaos transition

    International Nuclear Information System (INIS)

    Kryuchkyan, Gagik Yu.; Manvelyan, Suren B.

    2003-01-01

    We study the phenomena at the overlap of quantum chaos and nonclassical statistics for the time-dependent model of nonlinear oscillator. It is shown in the framework of Mandel Q parameter and Wigner function that the statistics of oscillatory excitation numbers is drastically changed in the order-to-chaos transition. The essential improvement of sub-Poissonian statistics in comparison with an analogous one for the standard model of driven anharmonic oscillator is observed for the regular operational regime. It is shown that in the chaotic regime, the system exhibits the range of sub-Poissonian and super-Poissonian statistics which alternate one to other depending on time intervals. Unusual dependence of the variance of oscillatory number on the external noise level for the chaotic dynamics is observed. The scaling invariance of the quantum statistics is demonstrated and its relation to dissipation and decoherence is studied

  13. Statistical Methods for Unusual Count Data: Examples From Studies of Microchimerism

    Science.gov (United States)

    Guthrie, Katherine A.; Gammill, Hilary S.; Kamper-Jørgensen, Mads; Tjønneland, Anne; Gadi, Vijayakrishna K.; Nelson, J. Lee; Leisenring, Wendy

    2016-01-01

    Natural acquisition of small amounts of foreign cells or DNA, referred to as microchimerism, occurs primarily through maternal-fetal exchange during pregnancy. Microchimerism can persist long-term and has been associated with both beneficial and adverse human health outcomes. Quantitative microchimerism data present challenges for statistical analysis, including a skewed distribution, excess zero values, and occasional large values. Methods for comparing microchimerism levels across groups while controlling for covariates are not well established. We compared statistical models for quantitative microchimerism values, applied to simulated data sets and 2 observed data sets, to make recommendations for analytic practice. Modeling the level of quantitative microchimerism as a rate via Poisson or negative binomial model with the rate of detection defined as a count of microchimerism genome equivalents per total cell equivalents tested utilizes all available data and facilitates a comparison of rates between groups. We found that both the marginalized zero-inflated Poisson model and the negative binomial model can provide unbiased and consistent estimates of the overall association of exposure or study group with microchimerism detection rates. The negative binomial model remains the more accessible of these 2 approaches; thus, we conclude that the negative binomial model may be most appropriate for analyzing quantitative microchimerism data. PMID:27769989

  14. Unusual event report from Oskarshamn

    International Nuclear Information System (INIS)

    1996-01-01

    The title of the report was intended to reflect the cause of the shutdown and the report to be regarded as a summary of the deficiencies that had been revealed and remedied. No single deficiency was regarded as reportable as an unusual event, but taken together the identified deficiencies deviated from the assumed safety level to the extent that it should be reported. The unusual event report refers to two main documents presenting measures taken to return to reported safety level, one concerning technical and one organizational measures

  15. Statistical Properties of Lorenz-like Flows, Recent Developments and Perspectives

    Science.gov (United States)

    Araujo, Vitor; Galatolo, Stefano; Pacifico, Maria José

    We comment on the mathematical results about the statistical behavior of Lorenz equations and its attractor, and more generally on the class of singular hyperbolic systems. The mathematical theory of such kind of systems turned out to be surprisingly difficult. It is remarkable that a rigorous proof of the existence of the Lorenz attractor was presented only around the year 2000 with a computer-assisted proof together with an extension of the hyperbolic theory developed to encompass attractors robustly containing equilibria. We present some of the main results on the statistical behavior of such systems. We show that for attractors of three-dimensional flows, robust chaotic behavior is equivalent to the existence of certain hyperbolic structures, known as singular-hyperbolicity. These structures, in turn, are associated with the existence of physical measures: in low dimensions, robust chaotic behavior for flows ensures the existence of a physical measure. We then give more details on recent results on the dynamics of singular-hyperbolic (Lorenz-like) attractors: (1) there exists an invariant foliation whose leaves are forward contracted by the flow (and further properties which are useful to understand the statistical properties of the dynamics); (2) there exists a positive Lyapunov exponent at every orbit; (3) there is a unique physical measure whose support is the whole attractor and which is the equilibrium state with respect to the center-unstable Jacobian; (4) this measure is exact dimensional; (5) the induced measure on a suitable family of cross-sections has exponential decay of correlations for Lipschitz observables with respect to a suitable Poincaré return time map; (6) the hitting time associated to Lorenz-like attractors satisfy a logarithm law; (7) the geometric Lorenz flow satisfies the Almost Sure Invariance Principle (ASIP) and the Central Limit Theorem (CLT); (8) the rate of decay of large deviations for the volume measure on the ergodic basin of

  16. 48 CFR 2832.114 - Unusual contract financing.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 6 2010-10-01 2010-10-01 true Unusual contract financing... Contracting Requirements CONTRACT FINANCING Non-Commercial Item Purchase Financing 2832.114 Unusual contract financing. The HCA, or designee at a level not lower than the BPC, is the official authorized to approve...

  17. Interaction of a quantum well with squeezed light: Quantum-statistical properties

    International Nuclear Information System (INIS)

    Sete, Eyob A.; Eleuch, H.

    2010-01-01

    We investigate the quantum statistical properties of the light emitted by a quantum well interacting with squeezed light from a degenerate subthreshold optical parametric oscillator. We obtain analytical solutions for the pertinent quantum Langevin equations in the strong-coupling and low-excitation regimes. Using these solutions we calculate the intensity spectrum, autocorrelation function, and quadrature squeezing for the fluorescent light. We show that the fluorescent light exhibits bunching and quadrature squeezing. We also show that the squeezed light leads to narrowing of the width of the spectrum of the fluorescent light.

  18. Toxic properties of nanostructures: current state of question

    International Nuclear Information System (INIS)

    Petrovskaya, E.G.; Smol'nik, N.S.; Mel'nov, S.B.

    2014-01-01

    Manifestation of the toxic properties of engineered nanomaterials in the interaction with biological objects defined unusual physicochemical properties, structural features and the size of nanoparticles. (authors)

  19. The Unusual Minimum of Cycle 23: Observations and Interpretation

    Science.gov (United States)

    Martens, Petrus C.; Nandy, D.; Munoz-Jaramillo, A.

    2009-05-01

    The current minimum of cycle 23 is unusual in its long duration, the very low level to which Total Solar Irradiance (TSI) has fallen, and the small flux of the open polar fields. The deep minimum of TSI seems to be related to an unprecedented dearth of polar faculae, and hence to the small amount of open flux. Based upon surface flux transport models it has been suggested that the causes of these phenomena may be an unusually vigorous meridional flow, or even a deviation from Joy's law resulting in smaller Joy angles than usual for emerging flux in cycle 23. There is also the possibility of a connection with the recently inferred emergence in polar regions of bipoles that systematically defy Hale's law. Much speculation has been going on as to the consequences of this exceptional minimum: are we entering another global minimum, is this the end of the 80 year period of exceptionally high solar activity, or is this just a statistical hiccup? Dynamo simulations are underway that may help answer this question. As an aside it must be mentioned that the current minimum of TSI puts an upper limit in the TSI input for global climate simulations during the Maunder minimum, and that a possible decrease in future solar activity will result in a very small but not insignificant reduction in the pace of global warming.

  20. Statistical properties of deep inelastic reactions

    International Nuclear Information System (INIS)

    Moretto, L.G.

    1983-08-01

    The multifaceted aspects of deep-inelastic heavy-ion collisions are discussed in terms of the statistical equilibrium limit. It is shown that a conditional statistical equilibrium, where a number of degrees of freedom are thermalized while others are still relaxing, prevails in most of these reactions. The individual degrees of freedom that have been explored experimentally are considered in their statistical equilibrium limit, and the extent to which they appear to be thermalized is discussed. The interaction between degrees of freedom on their way towards equilibrium is shown to create complex feedback phenomena that may lead to self-regulation. A possible example of self-regulation is shown for the process of energy partition between fragments promoted by particle exchange. 35 references

  1. Unusual raptor nests around the world

    Science.gov (United States)

    Ellis, D.H.; Craig, T.; Craig, E.; Postupalsky, S.; LaRue, C.T.; Nelson, R.W.; Anderson, D.W.; Henny, C.J.; Watson, J.; Millsap, B.A.; Dawson, J.W.; Cole, K.L.; Martin, E.M.; Margalida, A.; Kung, P.

    2009-01-01

    From surveys in many countries, we report raptors using unusual nesting materials (e.g., paper money, rags, metal, antlers, and large bones) and unusual nesting situations. For example, we documented nests of Steppe Eagles Aquila nipalensis and Upland Buzzards Buteo hemilasius on the ground beside well-traveled roads, Saker Falcon Falco cherrug eyries in attics and a cistern, and Osprey Pandion haliaetus nests on the masts of boats and on a suspended automobile. Other records include a Golden Eagle A. chrysaetos nest 7.0 m in height, believed to be the tallest nest ever described, and, for the same species, we report nesting in rudimentary nests. Some nest sites are within a few meters of known predators or competitors. These unusual observations may be important in revealing the plasticity of a species' behavioral repertoire. ?? 2009 The Raptor Research Foundation, Inc.

  2. Predicting statistical properties of open reading frames in bacterial genomes.

    Directory of Open Access Journals (Sweden)

    Katharina Mir

    Full Text Available An analytical model based on the statistical properties of Open Reading Frames (ORFs of eubacterial genomes such as codon composition and sequence length of all reading frames was developed. This new model predicts the average length, maximum length as well as the length distribution of the ORFs of 70 species with GC contents varying between 21% and 74%. Furthermore, the number of annotated genes is predicted with high accordance. However, the ORF length distribution in the five alternative reading frames shows interesting deviations from the predicted distribution. In particular, long ORFs appear more often than expected statistically. The unexpected depletion of stop codons in these alternative open reading frames cannot completely be explained by a biased codon usage in the +1 frame. While it is unknown if the stop codon depletion has a biological function, it could be due to a protein coding capacity of alternative ORFs exerting a selection pressure which prevents the fixation of stop codon mutations. The comparison of the analytical model with bacterial genomes, therefore, leads to a hypothesis suggesting novel gene candidates which can now be investigated in subsequent wet lab experiments.

  3. Statistical properties of nucleotides in human chromosomes 21 and 22

    International Nuclear Information System (INIS)

    Zhang Linxi; Sun Tingting

    2005-01-01

    In this paper the statistical properties of nucleotides in human chromosomes 21 and 22 are investigated. The n-tuple Zipf analysis with n = 3, 4, 5, 6, and 7 is used in our investigation. It is found that the most common n-tuples are those which consist only of adenine (A) and thymine (T), and the rarest n-tuples are those in which GC or CG pattern appears twice. With the n-tuples become more and more frequent, the double GC or CG pattern becomes a single GC or CG pattern. The percentage of four nucleotides in the rarest ten and the most common ten n-tuples are also considered in human chromosomes 21 and 22, and different behaviors are found in the percentage of four nucleotides. Frequency of appearance of n-tuple f(r) as a function of rank r is also examined. We find the n-tuple Zipf plot shows a power-law behavior for r n-1 and a rapid decrease for r > 4 n-1 . In order to explore the interior statistical properties of human chromosomes 21 and 22 in detail, we divide the chromosome sequence into some moving windows and we discuss the percentage of ξη (ξ, η = A, C, G, T) pair in those moving windows. In some particular regions, there are some obvious changes in the percentage of ξη pair, and there maybe exist functional differences. The normalized number of repeats N 0 (l) can be described by a power law: N 0 (l) ∼ l -μ . The distance distributions P 0 (S) between two nucleotides in human chromosomes 21 and 22 are also discussed. A two-order polynomial fit exists in those distance distributions: log P 0 (S) = a + bS + cS 2 , and it is quite different from the random sequence

  4. Probability distribution and statistical properties of spherically compensated cosmic regions in ΛCDM cosmology

    Science.gov (United States)

    Alimi, Jean-Michel; de Fromont, Paul

    2018-04-01

    The statistical properties of cosmic structures are well known to be strong probes for cosmology. In particular, several studies tried to use the cosmic void counting number to obtain tight constrains on dark energy. In this paper, we model the statistical properties of these regions using the CoSphere formalism (de Fromont & Alimi) in both primordial and non-linearly evolved Universe in the standard Λ cold dark matter model. This formalism applies similarly for minima (voids) and maxima (such as DM haloes), which are here considered symmetrically. We first derive the full joint Gaussian distribution of CoSphere's parameters in the Gaussian random field. We recover the results of Bardeen et al. only in the limit where the compensation radius becomes very large, i.e. when the central extremum decouples from its cosmic environment. We compute the probability distribution of the compensation size in this primordial field. We show that this distribution is redshift independent and can be used to model cosmic voids size distribution. We also derive the statistical distribution of the peak parameters introduced by Bardeen et al. and discuss their correlation with the cosmic environment. We show that small central extrema with low density are associated with narrow compensation regions with deep compensation density, while higher central extrema are preferentially located in larger but smoother over/under massive regions.

  5. Effects of Isospin mixing on statistical properties of 26Al and 30P

    International Nuclear Information System (INIS)

    Shriner, J.F. Jr.; Blackston, M.A.; Mahar, K.T.; Grossmann, C.A.; Mitchell, G.E.

    2000-01-01

    Odd-odd nuclides in the sd-shell have states of different isospin coexisting even near the ground state. Because isospin is not a perfect symmetry, this coexistence provides an opportunity to examine directly the effects of a broken symmetry on the statistical properties of a quantum system. We present results for the nuclides 26 Al and 30 P, for which the level schemes are relatively complete

  6. Nature and statistical properties of quasar associated absorption systems in the XQ-100 Legacy Survey

    DEFF Research Database (Denmark)

    Perrotta, Serena; D'Odorico, Valentina; Prochaska, J. Xavier

    2016-01-01

    We statistically study the physical properties of a sample of narrow absorption line (NAL) systems looking for empirical evidences to distinguish between intrinsic and intervening NALs without taking into account any a priori definition or velocity cut-off. We analyze the spectra of 100 quasars...

  7. Statistical properties of nonlinear one-dimensional wave fields

    Directory of Open Access Journals (Sweden)

    D. Chalikov

    2005-01-01

    Full Text Available A numerical model for long-term simulation of gravity surface waves is described. The model is designed as a component of a coupled Wave Boundary Layer/Sea Waves model, for investigation of small-scale dynamic and thermodynamic interactions between the ocean and atmosphere. Statistical properties of nonlinear wave fields are investigated on a basis of direct hydrodynamical modeling of 1-D potential periodic surface waves. The method is based on a nonstationary conformal surface-following coordinate transformation; this approach reduces the principal equations of potential waves to two simple evolutionary equations for the elevation and the velocity potential on the surface. The numerical scheme is based on a Fourier transform method. High accuracy was confirmed by validation of the nonstationary model against known solutions, and by comparison between the results obtained with different resolutions in the horizontal. The scheme allows reproduction of the propagation of steep Stokes waves for thousands of periods with very high accuracy. The method here developed is applied to simulation of the evolution of wave fields with large number of modes for many periods of dominant waves. The statistical characteristics of nonlinear wave fields for waves of different steepness were investigated: spectra, curtosis and skewness, dispersion relation, life time. The prime result is that wave field may be presented as a superposition of linear waves is valid only for small amplitudes. It is shown as well, that nonlinear wave fields are rather a superposition of Stokes waves not linear waves. Potential flow, free surface, conformal mapping, numerical modeling of waves, gravity waves, Stokes waves, breaking waves, freak waves, wind-wave interaction.

  8. Statistical properties of nonlinear one-dimensional wave fields

    Science.gov (United States)

    Chalikov, D.

    2005-06-01

    A numerical model for long-term simulation of gravity surface waves is described. The model is designed as a component of a coupled Wave Boundary Layer/Sea Waves model, for investigation of small-scale dynamic and thermodynamic interactions between the ocean and atmosphere. Statistical properties of nonlinear wave fields are investigated on a basis of direct hydrodynamical modeling of 1-D potential periodic surface waves. The method is based on a nonstationary conformal surface-following coordinate transformation; this approach reduces the principal equations of potential waves to two simple evolutionary equations for the elevation and the velocity potential on the surface. The numerical scheme is based on a Fourier transform method. High accuracy was confirmed by validation of the nonstationary model against known solutions, and by comparison between the results obtained with different resolutions in the horizontal. The scheme allows reproduction of the propagation of steep Stokes waves for thousands of periods with very high accuracy. The method here developed is applied to simulation of the evolution of wave fields with large number of modes for many periods of dominant waves. The statistical characteristics of nonlinear wave fields for waves of different steepness were investigated: spectra, curtosis and skewness, dispersion relation, life time. The prime result is that wave field may be presented as a superposition of linear waves is valid only for small amplitudes. It is shown as well, that nonlinear wave fields are rather a superposition of Stokes waves not linear waves. Potential flow, free surface, conformal mapping, numerical modeling of waves, gravity waves, Stokes waves, breaking waves, freak waves, wind-wave interaction.

  9. An Unusual Bone Loss Around Implants

    Directory of Open Access Journals (Sweden)

    Amirreza Rokn

    2013-01-01

    Full Text Available AbstractPre-implant disease is an inflammatory process, which can affect the surrounding tissues of a functional Osseointegrated implant that is usually as a result of a disequilibrium between the micro-flora and the body defense system.This case reports a 57 years old male with unusual bone loss around dental implants.This was an unusual case of peri-implantitis which occurred only in the implants on one side of the mouth although they all were unloaded implants.

  10. Statistical and Measurement Properties of Features Used in Essay Assessment. Research Report. ETS RR-04-21

    Science.gov (United States)

    Haberman, Shelby J.

    2004-01-01

    Statistical and measurement properties are examined for features used in essay assessment to determine the generalizability of the features across populations, prompts, and individuals. Data are employed from TOEFL® and GMAT® examinations and from writing for Criterion?.

  11. Statistical properties of the personal social network in the Facebook

    Science.gov (United States)

    Guo, Q.; Shao, F.; Hu, Z. L.; Liu, J. G.

    2013-10-01

    The statistical properties of the user interaction behaviors in a city have great significance for developing the network marketing strategy, promoting personalized service and so on. In this paper, we investigate the interaction property of the users from New Orleans network in the Facebook, and find that one's out-degree and in-degree are approximately the same. In addition, when the number of a user friends is less than 65, the number of their posts would linearly grow with the slope 4.2, but when one user's friends are more than 65, their posts would grow with the slope 2.1. Further, the average link weight is relatively flat when the out-degree ranges from 28 to 65, and before or after the section it is on the rise or in decline, respectively, from which we can conclude that one could not maintain stable and meaningful relationships with more than 65 people in a single city. We present a null model to reshuffle the network to guarantee that the empirical results are not obtained by accident. The result obtained after reshuffling suggests that there exists a limit that restricts people's social activities.

  12. Critical, statistical, and thermodynamical properties of lattice models

    Energy Technology Data Exchange (ETDEWEB)

    Varma, Vipin Kerala

    2013-10-15

    In this thesis we investigate zero temperature and low temperature properties - critical, statistical and thermodynamical - of lattice models in the contexts of bosonic cold atom systems, magnetic materials, and non-interacting particles on various lattice geometries. We study quantum phase transitions in the Bose-Hubbard model with higher body interactions, as relevant for optical lattice experiments of strongly interacting bosons, in one and two dimensions; the universality of the Mott insulator to superfluid transition is found to remain unchanged for even large three body interaction strengths. A systematic renormalization procedure is formulated to fully re-sum these higher (three and four) body interactions into the two body terms. In the strongly repulsive limit, we analyse the zero and low temperature physics of interacting hard-core bosons on the kagome lattice at various fillings. Evidence for a disordered phase in the Ising limit of the model is presented; in the strong coupling limit, the transition between the valence bond solid and the superfluid is argued to be first order at the tip of the solid lobe.

  13. Critical, statistical, and thermodynamical properties of lattice models

    International Nuclear Information System (INIS)

    Varma, Vipin Kerala

    2013-10-01

    In this thesis we investigate zero temperature and low temperature properties - critical, statistical and thermodynamical - of lattice models in the contexts of bosonic cold atom systems, magnetic materials, and non-interacting particles on various lattice geometries. We study quantum phase transitions in the Bose-Hubbard model with higher body interactions, as relevant for optical lattice experiments of strongly interacting bosons, in one and two dimensions; the universality of the Mott insulator to superfluid transition is found to remain unchanged for even large three body interaction strengths. A systematic renormalization procedure is formulated to fully re-sum these higher (three and four) body interactions into the two body terms. In the strongly repulsive limit, we analyse the zero and low temperature physics of interacting hard-core bosons on the kagome lattice at various fillings. Evidence for a disordered phase in the Ising limit of the model is presented; in the strong coupling limit, the transition between the valence bond solid and the superfluid is argued to be first order at the tip of the solid lobe.

  14. Local and global statistical dynamical properties of chaotic Markov analytic maps and repellers: A coarse grained and spectral perspective

    International Nuclear Information System (INIS)

    MacKernan, Donal; Basios, Vasileios

    2009-01-01

    The statistical properties of chaotic Markov analytic maps and equivalent repellers are investigated through matrix representations of the Frobenius-Perron operator (U). The associated basis sets are constructed using Chebyshev functions and Markov partitions which can be tailored to examine statistical dynamical properties associated with observables having support over local regions or for example, about periodic orbits. The decay properties of corresponding time correlations functions are given by a analytic expression of the spectra of U which is expected to be valid for a much larger class of systems than that studied here. An explicit and general expression is also derived for the correction factor to the dynamical zeta functions occurring when analytic function spaces are not invariant under U.

  15. An unusual mono-substituted Keggin anion-chain based 3D framework with 24-membered macrocycles as linker units

    International Nuclear Information System (INIS)

    Pang Haijun; Ma Huiyuan; Yu Yan; Yang Ming; Xun Ye; Liu Bo

    2012-01-01

    A new compound, [Cu I (H 2 O)(Hbpp) 2 ]⊂{[Cu I (bpp)] 2 [PW 11 Cu II O 39 ]} (1) (bpp=1,3-bis(4-pyridyl)propane), has been hydrothermally synthesized and structurally characterized by single crystal X-ray diffraction. In compound 1, the unusual –A–B–A–B– array mono-substituted Keggin anion-chains and 24-membered (Cubpp) 2 cation-macrocycles are linked together to form a (2, 4) connected 3D framework with channels of ca. 9.784×7.771 Å 2 along two directions, in which the [Cu(H 2 O)(Hbpp) 2 ] coordination fragments as guest components are trapped. The photocatalytic experiments of compound 1 were performed, which show a good catalytic activity of compound 1 for photodegradation of RhB. Furthermore, the IR, TGA and electrochemical properties of compound 1 were investigated. - Graphical abstract: An unusual example of mono-substituted Keggin anion-chain based hybrid compound that possesses a 3D structure has been synthesized, which offers a feasible route for synthesis of such compounds. Highlights: ► The first example of –A–B–A–B– array mono-substituted Keggin chain is observed. ► An unusual three dimensional structure based mono-substituted Keggin anion-chains. ► The photocatalysis and electrochemical properties of the title compound were studied.

  16. Statistical properties of single-mode emission in free-electron lasers

    International Nuclear Information System (INIS)

    Bertolotti, M.; Luks, A.; Perina, J.; Perinova, V.; Sibilia, C.

    1984-01-01

    The authors of this paper discuss the statistical properties of radiation produced in the free electron laser, in the case of singlemode emission when the system is used as an amplifier, with very small gain. The coherent states technique and the q-c number correspondence is employed, starting from the master-equation and obtaining the generalized Fokker-Planck equation for the anti-normal quasidistribution function. Solutions of Fokker-Planck equation provide the photocounting distribution and its factorial moments. No losses are included. It is shown that, in the short-time approximation, the radiation field exhibits antibunching, and that the photocounting distributions, when some suitable conditions on the field intensities are fulfilled, in the stationary regime shows a two-peak behavior, evidencing the existence of bistable states

  17. Statistical analysis of the factors that influenced the mechanical properties improvement of cassava starch films

    Science.gov (United States)

    Monteiro, Mayra; Oliveira, Victor; Santos, Francisco; Barros Neto, Eduardo; Silva, Karyn; Silva, Rayane; Henrique, João; Chibério, Abimaelle

    2017-08-01

    In order to obtain cassava starch films with improved mechanical properties in relation to the synthetic polymer in the packaging production, a complete factorial design 23 was carried out in order to investigate which factor significantly influences the tensile strength of the biofilm. The factors to be investigated were cassava starch, glycerol and modified clay contents. Modified bentonite clay was used as a filling material of the biofilm. Glycerol was the plasticizer used to thermoplastify cassava starch. The factorial analysis suggested a regression model capable of predicting the optimal mechanical property of the cassava starch film from the maximization of the tensile strength. The reliability of the regression model was tested by the correlation established with the experimental data through the following statistical analyse: Pareto graph. The modified clay was the factor of greater statistical significance on the observed response variable, being the factor that contributed most to the improvement of the mechanical property of the starch film. The factorial experiments showed that the interaction of glycerol with both modified clay and cassava starch was significant for the reduction of biofilm ductility. Modified clay and cassava starch contributed to the maximization of biofilm ductility, while glycerol contributed to the minimization.

  18. The nature of unusual luminescence in natural calcite, CaCO3

    Energy Technology Data Exchange (ETDEWEB)

    Gaft, M.; Nagli, L.; Panczer, G.; Waychunas, G.; Porat, N.

    2008-11-01

    The unusual luminescence of particular varieties of natural pink calcite (CaCO{sub 3}) samples was studied by laser-induced time-resolved luminescence spectroscopy at different temperatures. The luminescence is characterized by intense blue emission under short-wave UV lamp excitation with an extremely long decay time, accompanied by pink-orange luminescence under long wave UV excitation. Our investigation included optical absorption, natural thermostimulated luminescence (NTL) and Laser-Induced Breakdown Spectroscopy (LIBS) studies. Two luminescence centers were detected: a narrow violet band, with {lambda}{sub max} = 412 nm, {Delta} = 45 nm, two decay components of {tau}{sub 1} = 5 ns and {tau}{sub 2} = 7.2 ms, accompanied by very long afterglow, and an orange emission band with {lambda}{sub max} = 595 nm, {Delta} = 90 nm and {tau} = 5 ns. Both luminescence centers are thermally unstable with the blue emission disappearing after heating at 500 C, and the orange emission disappearing after heating at different temperatures starting from 230 C, although sometimes it is stable up to 500 C in different samples. Both centers have spectral-kinetic properties very unusual for mineral luminescence, which in combination with extremely low impurity concentrations, prevent their identification with specific impurity related emission. The most likely explanation of these observations may be the presence of radiation-induced luminescence centers. The long violet afterglow is evidently connected with trapped charge carrier liberation, with their subsequent migration through the valence band and ultimate recombination with a radiation-induced center responsible for the unusual violet luminescence.

  19. Computing physical properties with quantum Monte Carlo methods with statistical fluctuations independent of system size.

    Science.gov (United States)

    Assaraf, Roland

    2014-12-01

    We show that the recently proposed correlated sampling without reweighting procedure extends the locality (asymptotic independence of the system size) of a physical property to the statistical fluctuations of its estimator. This makes the approach potentially vastly more efficient for computing space-localized properties in large systems compared with standard correlated methods. A proof is given for a large collection of noninteracting fragments. Calculations on hydrogen chains suggest that this behavior holds not only for systems displaying short-range correlations, but also for systems with long-range correlations.

  20. Intermetallics structures, properties, and statistics

    CERN Document Server

    Steurer, Walter

    2016-01-01

    The focus of this book is clearly on the statistics, topology, and geometry of crystal structures and crystal structure types. This allows one to uncover important structural relationships and to illustrate the relative simplicity of most of the general structural building principles. It also allows one to show that a large variety of actual structures can be related to a rather small number of aristotypes. It is important that this book is readable and beneficial in the one way or another for everyone interested in intermetallic phases, from graduate students to experts in solid-state chemistry/physics/materials science. For that purpose it avoids using an enigmatic abstract terminology for the classification of structures. The focus on the statistical analysis of structures and structure types should be seen as an attempt to draw the background of the big picture of intermetallics, and to point to the white spots in it, which could be worthwhile exploring. This book was not planned as a textbook; rather, it...

  1. Application of Maximum Entropy Distribution to the Statistical Properties of Wave Groups

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The new distributions of the statistics of wave groups based on the maximum entropy principle are presented. The maximum entropy distributions appear to be superior to conventional distributions when applied to a limited amount of information. Its applications to the wave group properties show the effectiveness of the maximum entropy distribution. FFT filtering method is employed to obtain the wave envelope fast and efficiently. Comparisons of both the maximum entropy distribution and the distribution of Longuet-Higgins (1984) with the laboratory wind-wave data show that the former gives a better fit.

  2. Statistical optics

    CERN Document Server

    Goodman, Joseph W

    2015-01-01

    This book discusses statistical methods that are useful for treating problems in modern optics, and the application of these methods to solving a variety of such problems This book covers a variety of statistical problems in optics, including both theory and applications.  The text covers the necessary background in statistics, statistical properties of light waves of various types, the theory of partial coherence and its applications, imaging with partially coherent light, atmospheric degradations of images, and noise limitations in the detection of light. New topics have been introduced i

  3. Statistical distribution for generalized ideal gas of fractional-statistics particles

    International Nuclear Information System (INIS)

    Wu, Y.

    1994-01-01

    We derive the occupation-number distribution in a generalized ideal gas of particles obeying fractional statistics, including mutual statistics, by adopting a state-counting definition. When there is no mutual statistics, the statistical distribution interpolates between bosons and fermions, and respects a fractional exclusion principle (except for bosons). Anyons in a strong magnetic field at low temperatures constitute such a physical system. Applications to the thermodynamic properties of quasiparticle excitations in the Laughlin quantum Hall fluid are discussed

  4. Unusual radiological characteristics of teratoid/rhabdoid brain tumor ...

    African Journals Online (AJOL)

    We report a case of atypical teratoid rhabdoid brain tumor for 4 months old male child, who presented with unusual radiological findings, that can be confused with other brain tumors ,so we high light these unusual imaging features to aid in making correct diagnosis. Keywords: atypical teratoid–rhabdoid tumor, brain tumor, ...

  5. The testis: the unusual, the rare and the bizarre

    International Nuclear Information System (INIS)

    Stewart, V.R.; Sidhu, P.S.

    2007-01-01

    Ultrasound is the preferred technique when imaging the scrotal contents. Although appearances of many of the more common abnormalities present the examiner with no diagnostic difficulty, the more unusual conditions may present a considerable challenge. Many normal variants, unusual and rare abnormalities may be instantly recognized once seen. The current review highlights the more unusual and rare conditions affecting the scrotal contents in order to allow the reader the opportunity to gain knowledge of their existence and to aid future interpretation of the difficult examination

  6. 48 CFR 235.070 - Indemnification against unusually hazardous risks.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Indemnification against unusually hazardous risks. 235.070 Section 235.070 Federal Acquisition Regulations System DEFENSE... DEVELOPMENT CONTRACTING 235.070 Indemnification against unusually hazardous risks. ...

  7. Statistical Properties of Clear and Dark Duration Lengths

    Czech Academy of Sciences Publication Activity Database

    Brabec, Marek; Paulescu, M.; Badescu, V.

    2017-01-01

    Roč. 153, 1 September (2017), s. 508-518 ISSN 0038-092X Institutional support: RVO:67985807 Keywords : sunshine duration * clouds * solar irradiance * statistical lifetime modeling * cox regression * censored data Subject RIV: BB - Applied Statistics, Operational Research OBOR OECD: Statistics and probability Impact factor: 4.018, year: 2016

  8. Statistical inference for classification of RRIM clone series using near IR reflectance properties

    Science.gov (United States)

    Ismail, Faridatul Aima; Madzhi, Nina Korlina; Hashim, Hadzli; Abdullah, Noor Ezan; Khairuzzaman, Noor Aishah; Azmi, Azrie Faris Mohd; Sampian, Ahmad Faiz Mohd; Harun, Muhammad Hafiz

    2015-08-01

    RRIM clone is a rubber breeding series produced by RRIM (Rubber Research Institute of Malaysia) through "rubber breeding program" to improve latex yield and producing clones attractive to farmers. The objective of this work is to analyse measurement of optical sensing device on latex of selected clone series. The device using transmitting NIR properties and its reflectance is converted in terms of voltage. The obtained reflectance index value via voltage was analyzed using statistical technique in order to find out the discrimination among the clones. From the statistical results using error plots and one-way ANOVA test, there is an overwhelming evidence showing discrimination of RRIM 2002, RRIM 2007 and RRIM 3001 clone series with p value = 0.000. RRIM 2008 cannot be discriminated with RRIM 2014; however both of these groups are distinct from the other clones.

  9. High-Throughput Nanoindentation for Statistical and Spatial Property Determination

    Science.gov (United States)

    Hintsala, Eric D.; Hangen, Ude; Stauffer, Douglas D.

    2018-04-01

    Standard nanoindentation tests are "high throughput" compared to nearly all other mechanical tests, such as tension or compression. However, the typical rates of tens of tests per hour can be significantly improved. These higher testing rates enable otherwise impractical studies requiring several thousands of indents, such as high-resolution property mapping and detailed statistical studies. However, care must be taken to avoid systematic errors in the measurement, including choosing of the indentation depth/spacing to avoid overlap of plastic zones, pileup, and influence of neighboring microstructural features in the material being tested. Furthermore, since fast loading rates are required, the strain rate sensitivity must also be considered. A review of these effects is given, with the emphasis placed on making complimentary standard nanoindentation measurements to address these issues. Experimental applications of the technique, including mapping of welds, microstructures, and composites with varying length scales, along with studying the effect of surface roughness on nominally homogeneous specimens, will be presented.

  10. Some properties of the representation of the quasilocal observables in statistical mechanics and quantum field theory

    International Nuclear Information System (INIS)

    Testard, D.; Centre National de la Recherche Scientifique, 13 - Marseille

    1977-09-01

    For a finite non zero temperature state in Statistical Mechanics it is proved that the factor obtained in the corresponding representation of the quasilocal algebra has the property of Araki. The same result also holds for the 'wedge-algebras' of a hermitian scalar Wightman field

  11. Probing the statistical properties of unknown texts: application to the Voynich Manuscript.

    Science.gov (United States)

    Amancio, Diego R; Altmann, Eduardo G; Rybski, Diego; Oliveira, Osvaldo N; Costa, Luciano da F

    2013-01-01

    While the use of statistical physics methods to analyze large corpora has been useful to unveil many patterns in texts, no comprehensive investigation has been performed on the interdependence between syntactic and semantic factors. In this study we propose a framework for determining whether a text (e.g., written in an unknown alphabet) is compatible with a natural language and to which language it could belong. The approach is based on three types of statistical measurements, i.e. obtained from first-order statistics of word properties in a text, from the topology of complex networks representing texts, and from intermittency concepts where text is treated as a time series. Comparative experiments were performed with the New Testament in 15 different languages and with distinct books in English and Portuguese in order to quantify the dependency of the different measurements on the language and on the story being told in the book. The metrics found to be informative in distinguishing real texts from their shuffled versions include assortativity, degree and selectivity of words. As an illustration, we analyze an undeciphered medieval manuscript known as the Voynich Manuscript. We show that it is mostly compatible with natural languages and incompatible with random texts. We also obtain candidates for keywords of the Voynich Manuscript which could be helpful in the effort of deciphering it. Because we were able to identify statistical measurements that are more dependent on the syntax than on the semantics, the framework may also serve for text analysis in language-dependent applications.

  12. Unusual computed tomography findings and complications in acute appendicitis

    International Nuclear Information System (INIS)

    Palacio, Glaucia Andrade e Silva; D'Ippolito, Giuseppe

    2003-01-01

    The objective of this article is to describe and illustrate unusual computed tomography (CT) findings in patients with acute appendicitis. We reviewed the charts of 200 patients with clinical suspicion of acute appendicitis who were submitted to abdominal CT before surgery. Patients with unusual presentation or complications were selected for illustrating the main CT findings. Unusual complications of acute appendicitis were related to anomalous position of the appendix, contiguity to intraperitoneal organs such as the liver, gall bladder, annexes and the bladder and continuous use of anti inflammatory or antibiotics during the diagnostic process. We concluded that CT is a useful diagnostic tool in patients with complicated or unusual presentation acute appendicitis. The first step towards diagnosis in these cases i to have in mind the hypothesis of appendicitis in patients with acute abdominal pain. (author)

  13. Statistical properties of the ice particle distribution in stratiform clouds

    Science.gov (United States)

    Delanoe, J.; Tinel, C.; Testud, J.

    2003-04-01

    This paper presents an extensive analysis of several microphysical data bases CEPEX, EUCREX, CLARE and CARL to determine statistical properties of the Particle Size Distribution (PSD). The data base covers different type of stratiform clouds : tropical cirrus (CEPEX), mid-latitude cirrus (EUCREX) and mid-latitude cirrus and stratus (CARL,CLARE) The approach for analysis uses the concept of normalisation of the PSD developed by Testud et al. (2001). The normalization aims at isolating three independent characteristics of the PSD : its "intrinsic" shape, the "average size" of the spectrum and the ice water content IWC, "average size" is meant the mean mass weighted diameter. It is shown that concentration should be normalized by N_0^* proportional to IWC/D_m^4. The "intrinsic" shape is defined as F(Deq/D_m)=N(Deq)/N_0^* where Deq is the equivalent melted diameter. The "intrinsic" shape is found to be very stable in the range 001.5, more scatter is observed, but future analysis should decide if it is representative of real physical variation or statistical "error" due to counting problem. Considering an overall statistics over the full data base, a large scatter of the N_0^* against Dm plot is found. But in the case of a particular event or a particular leg of a flight, the N_0^* vs. Dm plot is much less scattered and shows a systematic trend for decaying of N_0^* when Dm increases. This trend is interpreted as the manifestation of the predominance of the aggregation process. Finally an important point for cloud remote sensing is investigated : the normalised relationships IWC/N_0^* against Z/N_0^* is much less scattered that the classical IWC against Z the radar reflectivity factor.

  14. A statistical characterization method for damping material properties and its application to structural-acoustic system design

    International Nuclear Information System (INIS)

    Jung, Byung C.; Lee, Doo Ho; Youn, Byeng D.; Lee, Soo Bum

    2011-01-01

    The performance of surface damping treatments may vary once the surface is exposed to a wide range of temperatures, because the performance of viscoelastic damping material is highly dependent on operational temperature. In addition, experimental data for dynamic responses of viscoelastic material are inherently random, which makes it difficult to design a robust damping layout. In this paper a statistical modeling procedure with a statistical calibration method is suggested for the variability characterization of viscoelastic damping material in constrained-layer damping structures. First, the viscoelastic material property is decomposed into two sources: (I) a random complex modulus due to operational temperature variability, and (II) experimental/model errors in the complex modulus. Next, the variability in the damping material property is obtained using the statistical calibration method by solving an unconstrained optimization problem with a likelihood function metric. Two case studies are considered to show the influence of the material variability on the acoustic performances in the structural-acoustic systems. It is shown that the variability of the damping material is propagated to that of the acoustic performances in the systems. Finally, robust and reliable damping layout designs of the two case studies are obtained through the reliability-based design optimization (RBDO) amidst severe variability in operational temperature and the damping material

  15. Statistical properties of curved polymer

    Indian Academy of Sciences (India)

    respective ground states decide the conformational statistics of the polymer. For semiflexible polymers, the relevant non-dimensional quantity is lp/L, where lp is the persistence length (which is proportional to the bending modulus k) and L is the contour length of the polymer. In the limit, lp/L ≪ 1, the polymer behaves as.

  16. Statistical Study of the Properties of Magnetosheath Lion Roars using MMS observations

    Science.gov (United States)

    Giagkiozis, S.; Wilson, L. B., III

    2017-12-01

    Intense whistler-mode waves of very short duration are frequently encountered in the magnetosheath. These emissions have been linked to mirror mode waves and the Earth's bow shock. They can efficiently transfer energy between different plasma populations. These electromagnetic waves are commonly referred to as Lion roars (LR), due to the sound generated when the signals are sonified. They are generally observed during dips of the magnetic field that are anti-correlated with increases of density. Using MMS data, we have identified more than 1750 individual LR burst intervals. Each emission was band-pass filtered and further split into >35,000 subintervals, for which the direction of propagation and the polarization were calculated. The analysis of subinterval properties provides a more accurate representation of their true nature than the more commonly used time- and frequency-averaged dynamic spectra analysis. The results of the statistical analysis of the wave properties will be presented.

  17. What limits production of unusual monoenoic fatty acids in transgenic plants?

    Science.gov (United States)

    Suh, Mi Chung; Schultz, David J; Ohlrogge, John B

    2002-08-01

    Unusual monounsaturated fatty acids are major constituents (greater than 80%) in seeds of Coriandrum sativum L. (coriander) and Thunbergia alata Bojer, as well as in glandular trichomes (greater than 80% derived products) of Pelargonium x hortorum (geranium). These diverged fatty acid structures are produced via distinct plastidial acyl-acyl carrier protein (ACP) desaturases. When expressed in Arabidopsis thaliana (L.) Heynh. under strong seed-specific promoters the unusual acyl-ACP desaturases resulted in accumulation of unusual monoene fatty acids at 1-15% of seed fatty acid mass. In this study, we have examined several factors that potentially limit higher production of unusual monoenes in transgenic oilseeds. (i) Immunoblots indicated that the introduced desaturases were expressed at levels equivalent to or higher than the endogenous delta9 18:0-ACP desaturase. However, the level of unusual fatty acid produced in transgenic plants was not correlated with the level of desaturase expression. (ii) The unusual desaturases were expressed in several backgrounds, including antisense 18:0-ACP desaturase plants, in fab1 mutants, and co-expressed with specialized ACP or ferredoxin isoforms. None of these experiments led to high production of expected products. (iii) No evidence was found for degradation of the unusual fatty acids during seed development. (iv) Petroselinic acid added to developing seeds was incorporated into triacylglycerol as readily as oleic acid, suggesting no major barriers to its metabolism by enzymes of glycerolipid assembly. (v) In vitro and in situ assay of acyl-ACP desaturases revealed a large discrepancy of activity when comparing unusual acyl-ACP desaturases with the endogenous delta9 18:0-ACP desaturase. The combined results, coupled with the sensitivity of acyl-ACP desaturase activity to centrifugation and low salt or detergent suggests low production of unusual monoenes in transgenic plants may be due to the lack of, or incorrect assemble of

  18. Cleft lip and palate: series of unusual clinical cases.

    Science.gov (United States)

    Paranaíba, Lívia Máris Ribeiro; Miranda, Roseli Teixeira de; Martelli, Daniella Reis Barbosa; Bonan, Paulo Rogério Ferreti; Almeida, Hudson de; Orsi Júnior, Julian Miranda; Martelli Júnior, Hercílio

    2010-01-01

    Cleft lip and/or palate (CL/P) represent the most common congenital anomalies of the face, corresponding to approximately 65% of all malformations of the craniofacial region. to describe unusual clinical cases of non-syndromic CL/P (CL/PNS), diagnosed in a reference service in Minas Gerais, Brazil, and correlate these alterations with possible risk factors. we carried out a retrospective study, between the years of 1992 and the 1st half of 2009, from medical records. Among the 778 cases of CL/PNS diagnosed in the period of 17 years, 5 (0.64%) were unusual CL/PNS, and all patients were male. It was found that among the 5 patients, 2 had incomplete right cleft lip with incomplete cleft palate, 2 were affected by left incomplete cleft lip and incomplete cleft palate, and 1 had a cleft lip and palate associated with complete right cleft palate. Risk factors such as consanguinity, maternal smoking and alcohol consumption, medication usage during pregnancy, history of abortion and/or stillbirths and maternal diseases were not associated with unusual CL/PNS. This study described 5 unusual cases of CL/PNS in a Brazilian population; no associations with the risk factors analyzed were seen. It also confirmed the unusualness of the prevalence of such alterations.

  19. STATISTICAL INSIGHT INTO THE BINDING REGIONS IN DISORDERED HUMAN PROTEOME

    Directory of Open Access Journals (Sweden)

    Uttam Pal

    2016-03-01

    Full Text Available The human proteome contains a significant number of intrinsically disordered proteins (IDPs. They show unusual structural features that enable them to participate in diverse cellular functions and play significant roles in cell signaling and reorganization processes. In addition, the actions of IDPs, their functional cooperativity, conformational alterations and folding often accompany binding to a target macromolecule. Applying bioinformatics approaches and with the aid of statistical methodologies, we investigated the statistical parameters of binding regions (BRs found in disordered human proteome. In this report, we detailed the bioinformatics analysis of binding regions found in the IDPs. Statistical models for the occurrence of BRs, their length distribution and percent occupancy in the parent proteins are shown. The frequency of BRs followed a Poisson distribution pattern with increasing expectancy with the degree of disorderedness. The length of the individual BRs also followed Poisson distribution with a mean of 6 residues, whereas, percentage of residues in BR showed a normal distribution pattern. We also explored the physicochemical properties such as the grand average of hydropathy (GRAVY and the theoretical isoelectric points (pIs. The theoretical pIs of the BRs followed a bimodal distribution as in the parent proteins. However, the mean acidic/basic pIs were significantly lower/higher than that of the proteins, respectively. We further showed that the amino acid composition of BRs was enriched in hydrophobic residues such as Ala, Val, Ile, Leu and Phe compared to the average sequence content of the proteins. Sequences in a BR showed conformational adaptability mostly towards flexible coil structure and followed by helix, however, the ordered secondary structural conformation was significantly lower in BRs than the proteins. Combining and comparing these statistical information of BRs with other methods may be useful for high

  20. Unusual MRI findings in grey matter heteropia

    International Nuclear Information System (INIS)

    Soto Ares, G.; Hamon-Kerautret, M.; Leclerc, X.; Pruvo, J.P.; Houlette, C.; Godefroy, O.

    1998-01-01

    We report unusual MRI patterns in patients with grey matter heterotopia. Standard T1- and T2-weighted spin-echo and inversion-recovery sequences were used in 22 patients presenting with seizures or developmental delay. The images were reviewed for signal change surrounding white matter and for atypical size, morphology or topography. We found 10 cases of subependymal heterotopias 11 of focal subcortical heterotopia and of diffuse subcortical heterotopia. On clinical or MRI grounds, 8 cases were considered unusual: 2 of the subependymal type, 2 of focal subcortical heterotopia with white matter abnormalities, 2 of focal subcortical heterotopia with no clinicoradiological correlation 1 of extensive hemispheric subcortical heterotopia and 1 of diffuse subcortical heterotopia confined to the frontal lobe. The classical classification of heterotopia enables easy radiological diagnosis even in cases with unusual patterns. In some cases, heterogeneity and high signal in surrounding white matter can be found. Cortical dysplasia is the most frequent associated malformation. (orig.)

  1. An unusual recurrence of pruritic creeping eruption after treatment

    African Journals Online (AJOL)

    abp

    2015-08-13

    Aug 13, 2015 ... However, an unusual recurrence of the disease in a Ghanaian male after standard treatment was observed ... dog or cat hookworm is not an unusual disease. However ... mistaken for fungal infections or inflammatory skin disorders. Indeed .... drug include dizziness, nausea, vomiting and intestinal cramps.

  2. Statistics of optical and geometrical properties of cirrus cloud over tibetan plateau measured by lidar and radiosonde

    Directory of Open Access Journals (Sweden)

    Dai Guangyao

    2018-01-01

    Full Text Available Cirrus clouds affect the energy budget and hydrological cycle of the earth’s atmosphere. The Tibetan Plateau (TP plays a significant role in the global and regional climate. Optical and geometrical properties of cirrus clouds in the TP were measured in July-August 2014 by lidar and radiosonde. The statistics and temperature dependences of the corresponding properties are analyzed. The cirrus cloud formations are discussed with respect to temperature deviation and dynamic processes.

  3. Unusual anatomy of maxillary central incisor with two roots

    Directory of Open Access Journals (Sweden)

    T S Ashwini Shivakumar

    2012-01-01

    Full Text Available Introduction: Knowledge of root canal morphology is essential for successful endodontic therapy. Failure to recognize unusual root canal anatomy may lead to unsuccessful endodontic treatment. Case Report: This case report describes the successful endodontic treatment of the maxillary central incisor with unusual anatomy of two roots and two root canals. A 23-year-old male patient was referred for dental consultation with discoloration of the maxillary right central incisor with periapical lesion, which revealed unusual anatomy of root on radiographic examination, and was confirmed upon exploration. Discussion: As described by Vertucci, the maxillary central incisor presents a single root and single root canal in 100% of the cases. However, few cases of maxillary central incisors with two canals were reported in the literature, most of which were associated with developmental anomalies like fusion, germination or dens invaginatus. Clinician should be aware of the unusual anatomical variations that should be detected by the different diagnostic resources available.

  4. Topological and statistical properties of nonlinear force-free fields

    Science.gov (United States)

    Mangalam, A.; Prasad, A.

    2018-01-01

    We use our semi-analytic solution of the nonlinear force-free field equation to construct three-dimensional magnetic fields that are applicable to the solar corona and study their statistical properties for estimating the degree of braiding exhibited by these fields. We present a new formula for calculating the winding number and compare it with the formula for the crossing number. The comparison is shown for a toy model of two helices and for realistic cases of nonlinear force-free fields; conceptually the formulae are nearly the same but the resulting distributions calculated for a given topology can be different. We also calculate linkages, which are useful topological quantities that are independent measures of the contribution of magnetic braiding to the total free energy and relative helicity of the field. Finally, we derive new analytical bounds for the free energy and relative helicity for the field configurations in terms of the linking number. These bounds will be of utility in estimating the braided energy available for nano-flares or for eruptions.

  5. Statistical properties of randomly broken objects and of multivalley structures in disordered systems

    International Nuclear Information System (INIS)

    Derrida, B.; Flyvbjerg, H.

    1987-02-01

    The statistical properties of the multivalley structure of disordered systems and of randomly broken objects have lots of features in common. For all these problems, if W s denotes the weight of the s th piece, we show that the probability distributions P 1 (W 1 ) of the largest piece W 1 , P 2 (W 2 ) of the second largest piece, and Π(Y) of Y = Σ s W s 2 have always singularities at W 1 = 1/n, W 2 = 1/n and Y = 1/n, n = 1, 2, 3,... (orig.)

  6. Emergence of unusual species of enterococci causing infections, South India

    Directory of Open Access Journals (Sweden)

    Rao Sambasiva R

    2005-03-01

    Full Text Available Abstract Background Enterococci tend to be one of the leading causes of nosocomial infections, with E. faecalis and E. faecium accounting up to 90% of the clinical isolates. Nevertheless, the incidence of other species of enterococci from clinical sources shows an alarming increase with the properties of intrinsic resistance to several antibiotics including beta-lactams and glycopeptides. Thus proper identification of enterococci to species level is quintessential for management and prevention of these bacteria in any healthcare facility. Hence this work was undertaken to study the prevalence of unusual species of enterococci causing human infections, in a tertiary care hospital in South India. Methods The study was conducted in a tertiary care hospital in South India from July 2001 to June 2003. Isolates of enterococci were collected from various clinical specimens and speciated using extensive phenotypic and physiological tests. Antimicrobial susceptibility testing were performed and interpreted as per NCCLS guidelines. Whole cell protein (WCP fingerprinting of enterococci were done for species validation by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE and analyzed computationally. Results Our study showed the prevalence of unusual (non-faecalis and non-faecium enterococci and atypical (biochemical variant species of enterococci as 19% (46 isolates and 5% (12 isolates respectively. The 7 unusual species (46 isolates isolated and confirmed by phenotypic characterization includes: 15 E. gallinarum (6.2%, 10 E. avium (4.1%, 6 E. raffinosus (2.5%, 6 E. hirae (2.5%, 4 E. mundtii (1.7%, 3 E. casseliflavus-including the two atypical isolates (1.2% and 2 E. durans (0.8%. The 12 atypical enterococcal species (5% that showed aberrant sugar reactions in conventional phenotyping were confirmed as E. faecalis, E. faecium and E. casseliflavus respectively by WCP fingerprinting. The antimicrobial susceptibility testing depicted the

  7. Oat cell carcinoma of the esophagus: Unusual radiological appearances

    Energy Technology Data Exchange (ETDEWEB)

    Bedi, D.G.; Shaw, M.T.

    1986-08-01

    Primary oat cell carcinoma of the esophagus is a very rare tumour. The radiographic appearance of the three cases described in this paper are unusual because they resemble benign lesions such as leiomyoma, fibrous polyp and candidiasis. It would be interesting to investigate whether such an unusual appearance is common for this neoplasm.

  8. An unusual oral habit presenting as Dentin Hypersensitivity | Afolabi ...

    African Journals Online (AJOL)

    We present the case of a 30-year-old man with an unusual oral habit- office pin chewing and filing of the front tooth which resulted in dentine hypersensitivity. Clinical relevance: The role of daily oral habits and techniques of cessation were suggested in the management of dentine hypersensitivity. Keywords: Unusual oral ...

  9. Thermal properties and stabilities of polymer thin films

    International Nuclear Information System (INIS)

    Kanaya, Toshiji; Kawashima, Kazuko; Inoue, Rintaro; Miyazaki, Tsukasa

    2009-01-01

    Recent extensive studies have revealed that polymer thin films showed very interesting but unusual thermal properties and stabilities. In the article we show that X-ray reflectivity and neutron reflectivity are very powerful tools to study the anomalous properties of polymer thin films. (author)

  10. Harmonic statistics

    International Nuclear Information System (INIS)

    Eliazar, Iddo

    2017-01-01

    The exponential, the normal, and the Poisson statistical laws are of major importance due to their universality. Harmonic statistics are as universal as the three aforementioned laws, but yet they fall short in their ‘public relations’ for the following reason: the full scope of harmonic statistics cannot be described in terms of a statistical law. In this paper we describe harmonic statistics, in their full scope, via an object termed harmonic Poisson process: a Poisson process, over the positive half-line, with a harmonic intensity. The paper reviews the harmonic Poisson process, investigates its properties, and presents the connections of this object to an assortment of topics: uniform statistics, scale invariance, random multiplicative perturbations, Pareto and inverse-Pareto statistics, exponential growth and exponential decay, power-law renormalization, convergence and domains of attraction, the Langevin equation, diffusions, Benford’s law, and 1/f noise. - Highlights: • Harmonic statistics are described and reviewed in detail. • Connections to various statistical laws are established. • Connections to perturbation, renormalization and dynamics are established.

  11. Harmonic statistics

    Energy Technology Data Exchange (ETDEWEB)

    Eliazar, Iddo, E-mail: eliazar@post.tau.ac.il

    2017-05-15

    The exponential, the normal, and the Poisson statistical laws are of major importance due to their universality. Harmonic statistics are as universal as the three aforementioned laws, but yet they fall short in their ‘public relations’ for the following reason: the full scope of harmonic statistics cannot be described in terms of a statistical law. In this paper we describe harmonic statistics, in their full scope, via an object termed harmonic Poisson process: a Poisson process, over the positive half-line, with a harmonic intensity. The paper reviews the harmonic Poisson process, investigates its properties, and presents the connections of this object to an assortment of topics: uniform statistics, scale invariance, random multiplicative perturbations, Pareto and inverse-Pareto statistics, exponential growth and exponential decay, power-law renormalization, convergence and domains of attraction, the Langevin equation, diffusions, Benford’s law, and 1/f noise. - Highlights: • Harmonic statistics are described and reviewed in detail. • Connections to various statistical laws are established. • Connections to perturbation, renormalization and dynamics are established.

  12. Statistical properties of highly excited quantum eigenstates of a strongly chaotic system

    International Nuclear Information System (INIS)

    Aurich, R.; Steiner, F.

    1992-06-01

    Statistical properties of highly excited quantal eigenstates are studied for the free motion (geodesic flow) on a compact surface of constant negative curvature (hyperbolic octagon) which represents a strongly chaotic system (K-system). The eigenstates are expanded in a circular-wave basis, and it turns out that the expansion coefficients behave as Gaussian pseudo-random numbers. It is shown that this property leads to a Gaussian amplitude distribution P(ψ) in the semiclassical limit, i.e. the wavefunctions behave as Gaussian random functions. This behaviour, which should hold for chaotic systems in general, is nicely confirmed for eigenstates lying 10000 states above the ground state thus probing the semiclassical limit. In addition, the autocorrelation function and the path-correlation function are calculated and compared with a crude semiclassical Bessel-function approximation. Agreement with the semiclassical prediction is only found, if a local averaging is performed over roughly 1000 de Broglie wavelengths. On smaller scales, the eigenstates show much more structure than predicted by the first semiclassical approximation. (orig.)

  13. Oat cell carcinoma of the esophagus: Unusual radiological appearances

    International Nuclear Information System (INIS)

    Bedi, D.G.; Shaw, M.T.

    1986-01-01

    Primary oat cell carcinoma of the esophagus is a very rare tumour. The radiographic appearance of the three cases described in this paper are unusual because they resemble benign lesions such as leiomyoma, fibrous polyp and candidiasis. It would be interesting to investigate whether such an unusual appearance is common for this neoplasm. (orig.)

  14. Geometric Approach to Quantum Statistical Mechanics and Application to Casimir Energy and Friction Properties

    International Nuclear Information System (INIS)

    Ichinose, Shoichi

    2010-01-01

    A geometric approach to general quantum statistical systems (including the harmonic oscillator) is presented. It is applied to Casimir energy and the dissipative system with friction. We regard the (N+1)-dimensional Euclidean coordinate system (X i ,τ) as the quantum statistical system of N quantum (statistical) variables (X τ ) and one Euclidean time variable (t). Introducing paths (lines or hypersurfaces) in this space (X τ ,t), we adopt the path-integral method to quantize the mechanical system. This is a new view of (statistical) quantization of the mechanical system. The system Hamiltonian appears as the area. We show quantization is realized by the minimal area principle in the present geometric approach. When we take a line as the path, the path-integral expressions of the free energy are shown to be the ordinary ones (such as N harmonic oscillators) or their simple variation. When we take a hyper-surface as the path, the system Hamiltonian is given by the area of the hyper-surface which is defined as a closed-string configuration in the bulk space. In this case, the system becomes a O(N) non-linear model. We show the recently-proposed 5 dimensional Casimir energy (ArXiv:0801.3064,0812.1263) is valid. We apply this approach to the visco-elastic system, and present a new method using the path-integral for the calculation of the dissipative properties.

  15. A study of outliers in statistical distributions of mechanical properties of structural steels

    International Nuclear Information System (INIS)

    Oefverbeck, P.; Oestberg, G.

    1977-01-01

    The safety against failure of pressure vessels can be assessed by statistical methods, so-called probabilistic fracture mechanics. The data base for such estimations is admittedly rather meagre, making it necessary to assume certain conventional statistical distributions. Since the failure rates arrived at are low, for nuclear vessels of the order of 10 - to 10 - per year, the extremes of the variables involved, among other things the mechanical properties of the steel used, are of particular interest. A question sometimes raised is whether outliers, or values exceeding the extremes in the assumed distributions, might occur. In order to explore this possibility a study has been made of strength values of three qualities of structural steels, available in samples of up to about 12,000. Statistical evaluation of these samples with respect to outliers, using standard methods for this purpose, revealed the presence of such outliers in most cases, with a frequency of occurrence of, typically, a few values per thousand, estimated by the methods described. Obviously, statistical analysis alone cannot be expected to shed any light on the causes of outliers. Thus, the interpretation of these results with respect to their implication for the probabilistic estimation of the integrety of pressure vessels must await further studies of a similar nature in which the test specimens corresponding to outliers can be recovered and examined metallographically. For the moment the results should be regarded only as a factor to be considered in discussions of the safety of pressure vessels. (author)

  16. Investigation of thermodynamic and mechanical properties of AlyIn1-yP alloys by statistical moment method

    Science.gov (United States)

    Ha, Vu Thi Thanh; Hung, Vu Van; Hanh, Pham Thi Minh; Tuyen, Nguyen Viet; Hai, Tran Thi; Hieu, Ho Khac

    2018-03-01

    The thermodynamic and mechanical properties of III-V zinc-blende AlP, InP semiconductors and their alloys have been studied in detail from statistical moment method taking into account the anharmonicity effects of the lattice vibrations. The nearest neighbor distance, thermal expansion coefficient, bulk moduli, specific heats at the constant volume and constant pressure of the zincblende AlP, InP and AlyIn1-yP alloys are calculated as functions of the temperature. The statistical moment method calculations are performed by using the many-body Stillinger-Weber potential. The concentration dependences of the thermodynamic quantities of zinc-blende AlyIn1-yP crystals have also been discussed and compared with those of the experimental results. Our results are reasonable agreement with earlier density functional theory calculations and can provide useful qualitative information for future experiments. The moment method then can be developed extensively for studying the atomistic structure and thermodynamic properties of nanoscale materials as well.

  17. Statistical properties of the normalized ice particle size distribution

    Science.gov (United States)

    Delanoë, Julien; Protat, Alain; Testud, Jacques; Bouniol, Dominique; Heymsfield, A. J.; Bansemer, A.; Brown, P. R. A.; Forbes, R. M.

    2005-05-01

    Testud et al. (2001) have recently developed a formalism, known as the "normalized particle size distribution (PSD)", which consists in scaling the diameter and concentration axes in such a way that the normalized PSDs are independent of water content and mean volume-weighted diameter. In this paper we investigate the statistical properties of the normalized PSD for the particular case of ice clouds, which are known to play a crucial role in the Earth's radiation balance. To do so, an extensive database of airborne in situ microphysical measurements has been constructed. A remarkable stability in shape of the normalized PSD is obtained. The impact of using a single analytical shape to represent all PSDs in the database is estimated through an error analysis on the instrumental (radar reflectivity and attenuation) and cloud (ice water content, effective radius, terminal fall velocity of ice crystals, visible extinction) properties. This resulted in a roughly unbiased estimate of the instrumental and cloud parameters, with small standard deviations ranging from 5 to 12%. This error is found to be roughly independent of the temperature range. This stability in shape and its single analytical approximation implies that two parameters are now sufficient to describe any normalized PSD in ice clouds: the intercept parameter N*0 and the mean volume-weighted diameter Dm. Statistical relationships (parameterizations) between N*0 and Dm have then been evaluated in order to reduce again the number of unknowns. It has been shown that a parameterization of N*0 and Dm by temperature could not be envisaged to retrieve the cloud parameters. Nevertheless, Dm-T and mean maximum dimension diameter -T parameterizations have been derived and compared to the parameterization of Kristjánsson et al. (2000) currently used to characterize particle size in climate models. The new parameterization generally produces larger particle sizes at any temperature than the Kristjánsson et al. (2000

  18. Statistical mechanics of violent relaxation

    International Nuclear Information System (INIS)

    Shu, F.H.

    1978-01-01

    We reexamine the foundations of Lynden-Bell's statistical mechanical discussion of violent relaxation in collisionless stellar systems. We argue that Lynden-Bell's formulation in terms of a continuum description introduces unnecessary complications, and we consider a more conventional formulation in terms of particles. We then find the exclusion principle discovered by Lynden-Bell to be quantitatively important only at phase densities where two-body encounters are no longer negligible. Since the edynamical basis for the exclusion principle vanishes in such cases anyway, Lynden-Bell statistics always reduces in practice to Maxwell-Boltzmann statistics when applied to stellar systems. Lynden-Bell also found the equilibrium distribution function generally to be a sum of Maxwellians with velocity dispersions dependent on the phase density at star formation. We show that this difficulty vanishes in the particulate description for an encounterless stellar system as long as stars of different masses are initially well mixed in phase space. Our methods also demonstrate the equivalence between Gibbs's formalism which uses the microcanonical ensemble and Boltzmann's formalism which uses a coarse-grained continuum description. In addition, we clarify the concept of irreversible behavior on a macroscopic scale for an encounterless stellar system. Finally, we comment on the use of unusual macroscopic constraints to simulate the effects of incomplete relaxation

  19. Statistical properties of spectra in harmonically trapped spin-orbit coupled systems

    DEFF Research Database (Denmark)

    V. Marchukov, O.; G. Volosniev, A.; V. Fedorov, D.

    2014-01-01

    We compute single-particle energy spectra for a one-body Hamiltonian consisting of a two-dimensional deformed harmonic oscillator potential, the Rashba spin-orbit coupling and the Zeeman term. To investigate the statistical properties of the obtained spectra as functions of deformation, spin......-orbit and Zeeman strengths we examine the distributions of the nearest neighbor spacings. We find that the shapes of these distributions depend strongly on the three potential parameters. We show that the obtained shapes in some cases can be well approximated with the standard Poisson, Brody and Wigner...... distributions. The Brody and Wigner distributions characterize irregular motion and help identify quantum chaotic systems. We present a special choices of deformation and spin-orbit strengths without the Zeeman term which provide a fair reproduction of the fourth-power repelling Wigner distribution. By adding...

  20. Origin of unusual bandgap shift and dual emission in organic-inorganic lead halide perovskites.

    Science.gov (United States)

    Dar, M Ibrahim; Jacopin, Gwénolé; Meloni, Simone; Mattoni, Alessandro; Arora, Neha; Boziki, Ariadni; Zakeeruddin, Shaik Mohammed; Rothlisberger, Ursula; Grätzel, Michael

    2016-10-01

    Emission characteristics of metal halide perovskites play a key role in the current widespread investigations into their potential uses in optoelectronics and photonics. However, a fundamental understanding of the molecular origin of the unusual blueshift of the bandgap and dual emission in perovskites is still lacking. In this direction, we investigated the extraordinary photoluminescence behavior of three representatives of this important class of photonic materials, that is, CH 3 NH 3 PbI 3 , CH 3 NH 3 PbBr 3 , and CH(NH 2 ) 2 PbBr 3 , which emerged from our thorough studies of the effects of temperature on their bandgap and emission decay dynamics using time-integrated and time-resolved photoluminescence spectroscopy. The low-temperature (photoluminescence of CH 3 NH 3 PbI 3 and CH 3 NH 3 PbBr 3 reveals two distinct emission peaks, whereas that of CH(NH 2 ) 2 PbBr 3 shows a single emission peak. Furthermore, irrespective of perovskite composition, the bandgap exhibits an unusual blueshift by raising the temperature from 15 to 300 K. Density functional theory and classical molecular dynamics simulations allow for assigning the additional photoluminescence peak to the presence of molecularly disordered orthorhombic domains and also rationalize that the unusual blueshift of the bandgap with increasing temperature is due to the stabilization of the valence band maximum. Our findings provide new insights into the salient emission properties of perovskite materials, which define their performance in solar cells and light-emitting devices.

  1. A social network's changing statistical properties and the quality of human innovation

    Science.gov (United States)

    Uzzi, Brian

    2008-06-01

    We examined the entire network of creative artists that made Broadway musicals, in the post-War period, a collaboration network of international acclaim and influence, with an eye to investigating how the network's structural features condition the relationship between individual artistic talent and the success of their musicals. Our findings show that some of the evolving topographical qualities of degree distributions, path lengths and assortativity are relatively stable with time even as collaboration patterns shift, which suggests their changes are only minimally associated with the ebb and flux of the success of new productions. In contrast, the clustering coefficient changed substantially over time and we found that it had a nonlinear association with the production of financially and artistically successful shows. When the clustering coefficient ratio is low or high, the financial and artistic success of the industry is low, while an intermediate level of clustering is associated with successful shows. We supported these findings with sociological theory on the relationship between social structure and collaboration and with tests of statistical inference. Our discussion focuses on connecting the statistical properties of social networks to their performance and the performance of the actors embedded within them.

  2. A social network's changing statistical properties and the quality of human innovation

    International Nuclear Information System (INIS)

    Uzzi, Brian

    2008-01-01

    We examined the entire network of creative artists that made Broadway musicals, in the post-War period, a collaboration network of international acclaim and influence, with an eye to investigating how the network's structural features condition the relationship between individual artistic talent and the success of their musicals. Our findings show that some of the evolving topographical qualities of degree distributions, path lengths and assortativity are relatively stable with time even as collaboration patterns shift, which suggests their changes are only minimally associated with the ebb and flux of the success of new productions. In contrast, the clustering coefficient changed substantially over time and we found that it had a nonlinear association with the production of financially and artistically successful shows. When the clustering coefficient ratio is low or high, the financial and artistic success of the industry is low, while an intermediate level of clustering is associated with successful shows. We supported these findings with sociological theory on the relationship between social structure and collaboration and with tests of statistical inference. Our discussion focuses on connecting the statistical properties of social networks to their performance and the performance of the actors embedded within them

  3. On the Statistical Properties of Cospectra

    Science.gov (United States)

    Huppenkothen, D.; Bachetti, M.

    2018-05-01

    In recent years, the cross-spectrum has received considerable attention as a means of characterizing the variability of astronomical sources as a function of wavelength. The cospectrum has only recently been understood as a means of mitigating instrumental effects dependent on temporal frequency in astronomical detectors, as well as a method of characterizing the coherent variability in two wavelength ranges on different timescales. In this paper, we lay out the statistical foundations of the cospectrum, starting with the simplest case of detecting a periodic signal in the presence of white noise, under the assumption that the same source is observed simultaneously in independent detectors in the same energy range. This case is especially relevant for detecting faint X-ray pulsars in detectors heavily affected by instrumental effects, including NuSTAR, Astrosat, and IXPE, which allow for even sampling and where the cospectrum can act as an effective way to mitigate dead time. We show that the statistical distributions of both single and averaged cospectra differ considerably from those for standard periodograms. While a single cospectrum follows a Laplace distribution exactly, averaged cospectra are approximated by a Gaussian distribution only for more than ∼30 averaged segments, dependent on the number of trials. We provide an instructive example of a quasi-periodic oscillation in NuSTAR and show that applying standard periodogram statistics leads to underestimated tail probabilities for period detection. We also demonstrate the application of these distributions to a NuSTAR observation of the X-ray pulsar Hercules X-1.

  4. Fractional statistics and quantum scaling properties of the integrable Penson-Kolb-Hubbard chain

    Science.gov (United States)

    Vitoriano, Carlindo; Coutinho-Filho, M. D.

    2010-09-01

    We investigate the ground-state and low-temperature properties of the integrable version of the Penson-Kolb-Hubbard chain. The model obeys fractional statistical properties, which give rise to fractional elementary excitations and manifest differently in the four regions of the phase diagram U/t versus n , where U is the Coulomb coupling, t is the correlated hopping amplitude, and n is the particle density. In fact, we can find local pair formation, fractionalization of the average occupation number per orbital k , or U - and n -dependent average electric charge per orbital k . We also study the scaling behavior near the U -driven quantum phase transitions and characterize their universality classes. Finally, it is shown that in the regime of parameters where local pair formation is energetically more favorable, the ground state exhibits power-law superconductivity; we also stress that above half filling the pair-hopping term stabilizes local Cooper pairs in the repulsive- U regime for U

  5. A statistical strategy to assess cleaning level of surfaces using fluorescence spectroscopy and Wilks’ ratio

    DEFF Research Database (Denmark)

    Stoica, Iuliana-Madalina; Babamoradi, Hamid; van den Berg, Frans

    2017-01-01

    •A statistical strategy combining fluorescence spectroscopy, multivariate analysis and Wilks’ ratio is proposed.•The method was tested both off-line and on-line having riboflavin as a (controlled) contaminant.•Wilks’ ratio signals unusual recordings based on shifts in variance and covariance...... structure described in in-control data....

  6. Unusual tumour ablations: report of difficult and interesting cases

    OpenAIRE

    Mauri, Giovanni; Nicosia, Luca; Varano, Gianluca Maria; Shyn, Paul; Sartori, Sergio; Tombesi, Paola; Di Vece, Francesca; Orsi, Franco; Solbiati, Luigi

    2017-01-01

    Image-guided ablations are nowadays applied in the treatment of a wide group of diseases and in different organs and regions, and every day interventional radiologists have to face more difficult and unusual cases of tumour ablation. In the present case review, we report four difficult and unusual cases, reporting some tips and tricks for a successful image-guided treatment.

  7. Optimization of Biodiesel-Diesel Blended Fuel Properties and Engine Performance with Ether Additive Using Statistical Analysis and Response Surface Methods

    Directory of Open Access Journals (Sweden)

    Obed M. Ali

    2015-12-01

    Full Text Available In this study, the fuel properties and engine performance of blended palm biodiesel-diesel using diethyl ether as additive have been investigated. The properties of B30 blended palm biodiesel-diesel fuel were measured and analyzed statistically with the addition of 2%, 4%, 6% and 8% (by volume diethyl ether additive. The engine tests were conducted at increasing engine speeds from 1500 rpm to 3500 rpm and under constant load. Optimization of independent variables was performed using the desirability approach of the response surface methodology (RSM with the goal of minimizing emissions and maximizing performance parameters. The experiments were designed using a statistical tool known as design of experiments (DoE based on RSM.

  8. Tasty but nasty? Exploring the role of sensory-liking and food appropriateness in the willingness to eat unusual novel foods like insects

    NARCIS (Netherlands)

    Tan Hui Shan, Grace; Fischer, A.R.H.; Trijp, van H.C.M.; Stieger, M.

    2016-01-01

    Unusual novel foods like insects are generally not considered to be appropriate as food in cultures where they are not commonly eaten, and are often rejected for reasons other than their intrinsic sensory properties. This study explores how the levels of sensory-liking and food appropriateness

  9. Equilibrium statistical mechanics

    CERN Document Server

    Mayer, J E

    1968-01-01

    The International Encyclopedia of Physical Chemistry and Chemical Physics, Volume 1: Equilibrium Statistical Mechanics covers the fundamental principles and the development of theoretical aspects of equilibrium statistical mechanics. Statistical mechanical is the study of the connection between the macroscopic behavior of bulk matter and the microscopic properties of its constituent atoms and molecules. This book contains eight chapters, and begins with a presentation of the master equation used for the calculation of the fundamental thermodynamic functions. The succeeding chapters highlight t

  10. Contributions to statistics

    CERN Document Server

    Mahalanobis, P C

    1965-01-01

    Contributions to Statistics focuses on the processes, methodologies, and approaches involved in statistics. The book is presented to Professor P. C. Mahalanobis on the occasion of his 70th birthday. The selection first offers information on the recovery of ancillary information and combinatorial properties of partially balanced designs and association schemes. Discussions focus on combinatorial applications of the algebra of association matrices, sample size analogy, association matrices and the algebra of association schemes, and conceptual statistical experiments. The book then examines latt

  11. Unusual radiological features in Paget's disease of bone

    International Nuclear Information System (INIS)

    Moore, T.E.; Kathol, M.H.; El-Khoury, G.Y.; Walker, C.W.; Gendall, P.W.; Whitten, C.G.

    1994-01-01

    The radiological diagnosis of Paget's disease of bone is usually straightforward because most cases conform to well-established classic descriptions. Diagnosis becomes more difficult, however, when radiological appearances are not typical or other disease processes mask or alter the behavior of Paget's disease. Examples are presented to illustrate four categories of unusual radiological presentation of Paget's disease; (1) unusual disease progression, (2) massive post-immobilization lysis, (3) metastatic spread to pagetic bone, and (4) vertebral end-plate destruction that mimics infection. (orig.)

  12. Statistical and dynamical properties of a dissipative kicked rotator

    Science.gov (United States)

    Oliveira, Diego F. M.; Leonel, Edson D.

    2014-11-01

    Some dynamical and statistical properties for a conservative as well as the dissipative problem of relativistic particles in a waveguide are considered. For the first time, two different types of dissipation namely: (i) due to viscosity and; (ii) due to inelastic collision (upon the kick) are considered individually and acting together. For the first case, and contrary to what is expected for the original Zaslavsky’s relativistic model, we show there is a critical parameter where a transition from local to global chaos occurs. On the other hand, after considering the introduction of dissipation also on the kick, the structure of the phase space changes in the sense that chaotic and periodic attractors appear. We study also the chaotic sea by using scaling arguments and we proposed an analytical argument to reinforce the validity of the scaling exponents obtained numerically. In principle such an approach can be extended to any two-dimensional map. Finally, based on the Lyapunov exponent, we show that the parameter space exhibits infinite families of self-similar shrimp-shape structures, corresponding to periodic attractors, embedded in a large region corresponding to chaotic attractors.

  13. Unusual causes of pneumothorax

    Science.gov (United States)

    Ouellette, Daniel R.; Parrish, Scott; Browning, Robert F.; Turner, J. Francis; Zarogoulidis, Konstantinos; Kougioumtzi, Ioanna; Dryllis, Georgios; Kioumis, Ioannis; Pitsiou, Georgia; Machairiotis, Nikolaos; Katsikogiannis, Nikolaos; Tsiouda, Theodora; Madesis, Athanasios; Karaiskos, Theodoros

    2014-01-01

    Pneumothorax is divided to primary and secondary. It is a situation that requires immediate treatment, otherwise it could have severe health consequences. Pneumothorax can be treated either by thoracic surgeons, or pulmonary physicians. In our current work, we will focus on unusual cases of pneumothorax. We will provide the etiology and treatment for each case, also a discussion will be made for each situation. PMID:25337394

  14. New naphthalene polyimide with unusual molar absorption coefficient and excited state properties: Synthesis, photophysics and electrochemistry

    Energy Technology Data Exchange (ETDEWEB)

    Ozser, Mustafa E. [Girne American University, Faculty of Engineering and Architecture, Department of Industrial Engineering, Girne, North Cyprus (Cyprus); Yucekan, Ilke; Bodapati, Jagadeesh B. [Eastern Mediterranean University, Faculty of Arts and Sciences, Department of Chemistry, Famagusta, North Cyprus (Cyprus); Icil, Huriye, E-mail: huriye.icil@emu.edu.tr [Eastern Mediterranean University, Faculty of Arts and Sciences, Department of Chemistry, Famagusta, North Cyprus (Cyprus)

    2013-11-15

    A high molecular weight 1,4,5,8-naphthalene polyimide (ENPI) by one-step polycondensation mechanism and for comparison its monomeric diimide (ENDI) were synthesized; the photophysical and electrochemical properties were studied in detail for ENPI. Monomer has shown unusual insolubility so that the characterization proven to be difficult, whereas ENPI has shown better solubility. The molecular weight data obtained by GPC for the polymer were M{sub n}=8240 and M{sub w}=34,000 g mol{sup −1} respectively with a polydispersity of 4.13. The polyimide exhibited outstandingly high molar absorption coefficients as 599,000, 1,021,000, and 972,700 M{sup −1} cm{sup −1}, which is first time reported in literature for the characteristic 0–2, 0–1, and 0–0 electronic transitions, respectively. ENPI showed concentration dependent and red shifted excimer emission in 1,1,2,2-tetrachloroethane (TCE). The polymer has undergone multielectron reductions in CHCl{sub 3} solution below 100 mV s{sup −1} scan rates which merged into two reversible one-electron reduction peaks at higher scan rates. In solid-state, similar scan rate dependent reduction peaks were noticed. The LUMO, HOMO and optical band gap values obtained for ENPI were −3.73, −6.91, and 3.18 eV respectively. ENDI polymer with striking features has great potential as new sensitizer for efficient dye sensitized organic cells. Highlights: • A high molecular weight naphthalene polyimide was synthesized (M{sub w}=34,000 g mol{sup −1}). • The oligoether polyimide exhibited outstanding molar absorptivity (972,700 M{sup −1} cm{sup −1}). • A red shifted excimer emission has been observed. • The polymer has undergone multielectron reductions.

  15. Unusual imaging characteristics of complicated hydatid disease

    International Nuclear Information System (INIS)

    Turgut, Ahmet Tuncay; Altin, Levent; Topcu, Salih; Kilicoglu, Buelent; Altinok, Tamer; Kaptanoglu, Erkan; Karademir, Alp; Kosar, Ugur

    2007-01-01

    Hydatid disease, a worldwide zoonosis, is caused by the larval stage of the Echinococcus tapeworm. Although the liver and the lungs are the most frequently involved organs in the body, hydatid cysts of other organs are unusual. Radiologically, they usually demonstrate typical imaging findings, but unusual imaging characteristics of complicated cyst of hydatid disease, associated with high morbidity and mortality, are rarely described in the literature. The purpose of this study is to review the general features of hydatidosis and to discuss atypical imaging characteristics of the complicated hydatid disease in the human, with an emphasis on structure and rupture of the cystic lesion as well as ultrasonography (USG), computed tomography (CT), and magnetic resonance imaging (MRI) features of the disease. In our study, the available literature and images of the cases with complicated hydatidosis involving liver, lung, brain, spine and orbit were reviewed retrospectively. In hydatid disease, there are many potential local and systemic complications due to secondary involvement in almost any anatomic location in humans. Radiologically, in addition to the presence of atypical findings such as perifocal edema, non-homogenous contrast enhancement, multiplicity or septations and calcification, various unusual manifestations due to rupture or infection of the cyst have been observed in our cases with complicated hydatid disease. To prevent subsequent acute catastrophic results and the development of recurrences in various organs, it should be kept in mind that complicated hydatid cysts can cause unusual USG, CT, and MRI findings, in addition to typical ones, in endemic areas. Therefore, familiarity with atypical radiological appearances of complicated hydatid disease may be valuable in making a correct diagnosis and treatment

  16. Unusual imaging characteristics of complicated hydatid disease

    Energy Technology Data Exchange (ETDEWEB)

    Turgut, Ahmet Tuncay [Department of Radiology, Ankara Training and Research Hospital, Ankara (Turkey)]. E-mail: ahmettuncayturgut@yahoo.com; Altin, Levent [Department of Radiology, Numune Training and Research Hospital, Ankara (Turkey); Topcu, Salih [Department of Thoracic Surgery, Faculty of Medicine, Kocaeli University, Izmit (Turkey); Kilicoglu, Buelent [Department of 4th General Surgery, Ankara Training and Research Hospital, Ankara (Turkey); Altinok, Tamer [Department of Thoracic Surgery, Meram Faculty of Medicine, Selcuk University, Konya (Turkey); Kaptanoglu, Erkan [Department of Neurosurgery, Numune Training and Research Hospital, Ankara (Turkey); Karademir, Alp [Department of Radiology, Numune Training and Research Hospital, Ankara (Turkey); Kosar, Ugur [Department of Radiology, Ankara Training and Research Hospital, Ankara (Turkey)

    2007-07-15

    Hydatid disease, a worldwide zoonosis, is caused by the larval stage of the Echinococcus tapeworm. Although the liver and the lungs are the most frequently involved organs in the body, hydatid cysts of other organs are unusual. Radiologically, they usually demonstrate typical imaging findings, but unusual imaging characteristics of complicated cyst of hydatid disease, associated with high morbidity and mortality, are rarely described in the literature. The purpose of this study is to review the general features of hydatidosis and to discuss atypical imaging characteristics of the complicated hydatid disease in the human, with an emphasis on structure and rupture of the cystic lesion as well as ultrasonography (USG), computed tomography (CT), and magnetic resonance imaging (MRI) features of the disease. In our study, the available literature and images of the cases with complicated hydatidosis involving liver, lung, brain, spine and orbit were reviewed retrospectively. In hydatid disease, there are many potential local and systemic complications due to secondary involvement in almost any anatomic location in humans. Radiologically, in addition to the presence of atypical findings such as perifocal edema, non-homogenous contrast enhancement, multiplicity or septations and calcification, various unusual manifestations due to rupture or infection of the cyst have been observed in our cases with complicated hydatid disease. To prevent subsequent acute catastrophic results and the development of recurrences in various organs, it should be kept in mind that complicated hydatid cysts can cause unusual USG, CT, and MRI findings, in addition to typical ones, in endemic areas. Therefore, familiarity with atypical radiological appearances of complicated hydatid disease may be valuable in making a correct diagnosis and treatment.

  17. Unusual causes of obstructive jaundice. Computed tomography

    International Nuclear Information System (INIS)

    Rodriguez, E.; Pombo, F.; Cao, I.; Fernandez, R.; Riba da, M.

    1998-01-01

    The purpose of this study is to present selected computed tomography (CT) images showing unusual causes of obstructive jaundice. We reviewed retrospectively the Ct findings of obstructive jaundice in 227 patients. The most common causes of biliary obstruction were adenocarcinoma of the pancreatic head (n=77) and cholangiocarcinoma (n=65). In 13 cases (5.7%), the etiology of obstructive jaundice was unusual or exceptional: tuberculous adenitis (n=3), obstruction of afferent loop (n=2)signet ring cell adenocarcinoma (n=3); in duodenum, gallbladder and papilla of Water), Mirizzi syndrome (n=1), adenocarcinoma of the hepatic flexure (n=1), choledochal cyst (n=1) and pancreatic lymphoma (n=1). (Author) 13 refs

  18. Statistical evaluation of the mechanical properties of high-volume class F fly ash concretes

    KAUST Repository

    Yoon, Seyoon

    2014-03-01

    High-Volume Fly Ash (HVFA) concretes are seen by many as a feasible solution for sustainable, low embodied carbon construction. At the moment, fly ash is classified as a waste by-product, primarily of thermal power stations. In this paper the authors experimentally and statistically investigated the effects of mix-design factors on the mechanical properties of high-volume class F fly ash concretes. A total of 240 and 32 samples were produced and tested in the laboratory to measure compressive strength and Young\\'s modulus respectively. Applicability of the CEB-FIP (Comite Euro-international du Béton - Fédération Internationale de la Précontrainte) and ACI (American Concrete Institute) Building Model Code (Thomas, 2010; ACI Committee 209, 1982) [1,2] to the experimentally-derived mechanical property data for HVFA concretes was established. Furthermore, using multiple linear regression analysis, Mean Squared Residuals (MSRs) were obtained to determine whether a weight- or volume-based mix proportion is better to predict the mechanical properties of HVFA concrete. The significance levels of the design factors, which indicate how significantly the factors affect the HVFA concrete\\'s mechanical properties, were determined using analysis of variance (ANOVA) tests. The results show that a weight-based mix proportion is a slightly better predictor of mechanical properties than volume-based one. The significance level of fly ash substitution rate was higher than that of w/b ratio initially but reduced over time. © 2014 Elsevier Ltd. All rights reserved.

  19. Effects of thickness on the statistical properties of the Barkhausen noise in amorphous films

    International Nuclear Information System (INIS)

    Santi, L.; Bohn, F.; Viegas, A.D.C.; Durin, G.; Magni, A.; Bonin, R.; Zapperi, S.; Sommer, R.L.

    2006-01-01

    The statistical properties of the Barkhausen noise (BN) in thin amorphous films are studied as a function of both the nominal composition and the thickness. BN was observed in single films with nominal compositions Fe 73.5 Cu 1 Nb 3 Si 22.5-x B x (with x=4 and 9) in the thickness range 20nm-5μm. The distributions of Barkhausen jump sizes and duration times were obtained and fitted to power laws with critical exponents τ=1.25+/-0.05 and α=1.60+/-0.05, respectively

  20. Large, cold, and unusual molecular cloud in Monoceros

    International Nuclear Information System (INIS)

    Maddalena, R.J.; Thaddeus, P.; and Columbia University)

    1985-01-01

    Observations of the J = 1 → 0 rotational transition of CO near the galactic plane in Monoceros (lroughly-equal216 0 ) reveal a molecular cloud with unusually low peak CO temperatures (T/sub R/ -1 ) typical of much warmer clouds. At the assumed distance of 3 kpc, the cloud is large (250 x 100 pc), has a mass of 7-11 x 10 5 M/sub sun/, and is well removed from the galactic midplane (130 pc). Except for a possible H II region, all the signs of star formation usually shown by clouds of comparable mass are missing. The cloud, unlike cloud complexes of similar size, is a single, continuous object that apparently has not been torn apart by star formation. Clouds with such properties are rare in the Galaxy; only one or two similar objects have been found. We discuss the possibility that the cloud is young and not yet forming stars but will evolve into a typical cloud complex once star formation begins

  1. Experimental research of vehicle traction properties for reconstruction of traffic accidents

    Directory of Open Access Journals (Sweden)

    Dudziak Marian

    2018-01-01

    Full Text Available In order to broaden the database of motor vehicle traction properties in unusual conditions, the research team has performed experimental studies: on wet and snow-covered surfaces. Tests of vehicles equipped with winter tyres with non-skid snow chains have been performed on snow-covered surfaces. It has been shown that on snowy surface chains affect vehicle traction properties, mostly during acceleration. They increase the rate of acceleration up to 50% compared to a vehicle with winter tyres without chains. The results of the performed research can be the basis for the full reconstruction of road accidents under these conditions. Knowledge of traction properties of cars in difficult and unusual conditions is an important cognitive factor and serves to improve road safety.

  2. Statistical properties of a utility measure of observer performance compared to area under the ROC curve

    Science.gov (United States)

    Abbey, Craig K.; Samuelson, Frank W.; Gallas, Brandon D.; Boone, John M.; Niklason, Loren T.

    2013-03-01

    The receiver operating characteristic (ROC) curve has become a common tool for evaluating diagnostic imaging technologies, and the primary endpoint of such evaluations is the area under the curve (AUC), which integrates sensitivity over the entire false positive range. An alternative figure of merit for ROC studies is expected utility (EU), which focuses on the relevant region of the ROC curve as defined by disease prevalence and the relative utility of the task. However if this measure is to be used, it must also have desirable statistical properties keep the burden of observer performance studies as low as possible. Here, we evaluate effect size and variability for EU and AUC. We use two observer performance studies recently submitted to the FDA to compare the EU and AUC endpoints. The studies were conducted using the multi-reader multi-case methodology in which all readers score all cases in all modalities. ROC curves from the study were used to generate both the AUC and EU values for each reader and modality. The EU measure was computed assuming an iso-utility slope of 1.03. We find mean effect sizes, the reader averaged difference between modalities, to be roughly 2.0 times as big for EU as AUC. The standard deviation across readers is roughly 1.4 times as large, suggesting better statistical properties for the EU endpoint. In a simple power analysis of paired comparison across readers, the utility measure required 36% fewer readers on average to achieve 80% statistical power compared to AUC.

  3. Interpretation of unusual events from CERN and DESY

    International Nuclear Information System (INIS)

    Hall, L.J.; Jaffee, R.L.; Rosner, J.L.

    1984-01-01

    Several classes of interesting and unusual events from the Sp-barpS and from PETRA are studied with two purposes in mind. Firstly, varieties of background within the standard SU(3)xSU(2)xU(1) model are described, together with estimates of the number of expected events. Secondly, a review of the recent explanations of the events involving new physics is given. Critical assessments of these proposals focus on the assumptions made, expected rates for the unusual events, and the ability to account for events of several categories

  4. Statistical mechanics and dynamics of solvable models with long-range interactions

    International Nuclear Information System (INIS)

    Campa, Alessandro; Dauxois, Thierry; Ruffo, Stefano

    2009-01-01

    For systems with long-range interactions, the two-body potential decays at large distances as V(r)∼1/r α , with α≤d, where d is the space dimension. Examples are: gravitational systems, two-dimensional hydrodynamics, two-dimensional elasticity, charged and dipolar systems. Although such systems can be made extensive, they are intrinsically non additive: the sum of the energies of macroscopic subsystems is not equal to the energy of the whole system. Moreover, the space of accessible macroscopic thermodynamic parameters might be non convex. The violation of these two basic properties of the thermodynamics of short-range systems is at the origin of ensemble inequivalence. In turn, this inequivalence implies that specific heat can be negative in the microcanonical ensemble, and temperature jumps can appear at microcanonical first order phase transitions. The lack of convexity allows us to easily spot regions of parameter space where ergodicity may be broken. Historically, negative specific heat had been found for gravitational systems and was thought to be a specific property of a system for which the existence of standard equilibrium statistical mechanics itself was doubted. Realizing that such properties may be present for a wider class of systems has renewed the interest in long-range interactions. Here, we present a comprehensive review of the recent advances on the statistical mechanics and out-of-equilibrium dynamics of solvable systems with long-range interactions. The core of the review consists in the detailed presentation of the concept of ensemble inequivalence, as exemplified by the exact solution, in the microcanonical and canonical ensembles, of mean-field type models. Remarkably, the entropy of all these models can be obtained using the method of large deviations. Long-range interacting systems display an extremely slow relaxation towards thermodynamic equilibrium and, what is more striking, the convergence towards quasi-stationary states. The

  5. Magnetic field drift shell splitting: Cause of unusual dayside particle pitch angle distributions during storms and substorms

    International Nuclear Information System (INIS)

    Sibeck, D.G.; McEntire, R.W.; Lui, A.T.Y.; Lopez, R.E.; Krimigis, S.M.

    1987-01-01

    We present a magnetic field drift shell--splitting model for the unusual butterfly and head-and-shoulder energetic (E>25 keV) particle pitch angle distributions (PADs) which appear deep within the dayside magnetosphere during the course of storms and substorms. Drift shell splitting separates the high and low pitch angle particles in nightside injections as they move to the dayside magnetosphere, so that the higher pitch angle particles move radially away from Earth. Consequently, butterfly PADs with a surplus of low pitch angle particles form on the inner edge of the injection, but head-and-shoulder PADs with a surplus of high pitch angle particles from on the outer edge. A similar process removes high pitch angle particles from the inner dayside magnetosphere during storms, leaving the remaining lower pitch angle particles to form butterfly PADs on the inner edge of the ring current. A detailed case and statistical study of CCE/MEPA observations, as well as a review of previous work, shows most examples of unusual PADs to be consistent with the model. copyright American Geophysical Union 1987

  6. Recurring waterbird mortalities and unusual etiologies

    Science.gov (United States)

    Cole, Rebecca A.; Franson, J. Christian; Boere, Gerard C.; Galbraith, Colin A.; Stroud, David A.

    2006-01-01

    Over the last decade, the National Wildlife Health Center of the United States Geological Survey has documented various largescale mortalities of birds caused by infectious and non-infectious disease agents. Some of these mortality events have unusual or unidentified etiologies and have been recurring. While some of the causes of mortalities have been elucidated, others remain in various stages of investigation and identification. Two examples are discussed: 1) Leyogonimus polyoon (Class: Trematoda), not found in the New World until 1999, causes severe enteritis and has killed over 15 000 American Coot Fulica americana in the upper mid-western United States. The geographic range of this parasite within North America is predicted to be limited to the Great Lakes Basin. 2) In the early 1990s, estimates of up to 6% of the North American population of the Eared Grebe Podiceps nigricollis died at Salton Sea, California, with smaller mortalities occurring throughout the 1990s. Birds were observed to have unusual preening behaviour, and to congregate at freshwater drains and move onto land. Suggested etiologies included interactions of contaminants, immuno-suppression, an unusual form of a bacterial disease, and an unknown biotoxin. During studies carried out from 2000 to 2003, Eared Grebe mortality did not approach the level seen in the early 1990s and, although bacteria were identified as minor factors, the principal cause of mortality remains undetermined. The potential population impact of these emerging and novel disease agents is currently unknown.

  7. Evaluation of statistical and geostatistical models of digital soil properties mapping in tropical mountain regions

    Directory of Open Access Journals (Sweden)

    Waldir de Carvalho Junior

    2014-06-01

    Full Text Available Soil properties have an enormous impact on economic and environmental aspects of agricultural production. Quantitative relationships between soil properties and the factors that influence their variability are the basis of digital soil mapping. The predictive models of soil properties evaluated in this work are statistical (multiple linear regression-MLR and geostatistical (ordinary kriging and co-kriging. The study was conducted in the municipality of Bom Jardim, RJ, using a soil database with 208 sampling points. Predictive models were evaluated for sand, silt and clay fractions, pH in water and organic carbon at six depths according to the specifications of the consortium of digital soil mapping at the global level (GlobalSoilMap. Continuous covariates and categorical predictors were used and their contributions to the model assessed. Only the environmental covariates elevation, aspect, stream power index (SPI, soil wetness index (SWI, normalized difference vegetation index (NDVI, and b3/b2 band ratio were significantly correlated with soil properties. The predictive models had a mean coefficient of determination of 0.21. Best results were obtained with the geostatistical predictive models, where the highest coefficient of determination 0.43 was associated with sand properties between 60 to 100 cm deep. The use of a sparse data set of soil properties for digital mapping can explain only part of the spatial variation of these properties. The results may be related to the sampling density and the quantity and quality of the environmental covariates and predictive models used.

  8. Statistical properties of the coarse-grained velocity gradient tensor in turbulence: Monte-Carlo simulations of the tetrad model

    International Nuclear Information System (INIS)

    Pumir, Alain; Naso, Aurore

    2010-01-01

    A proper description of the velocity gradient tensor is crucial for understanding the dynamics of turbulent flows, in particular the energy transfer from large to small scales. Insight into the statistical properties of the velocity gradient tensor and into its coarse-grained generalization can be obtained with the help of a stochastic 'tetrad model' that describes the coarse-grained velocity gradient tensor based on the evolution of four points. Although the solution of the stochastic model can be formally expressed in terms of path integrals, its numerical determination in terms of the Monte-Carlo method is very challenging, as very few configurations contribute effectively to the statistical weight. Here, we discuss a strategy that allows us to solve the tetrad model numerically. The algorithm is based on the importance sampling method, which consists here of identifying and sampling preferentially the configurations that are likely to correspond to a large statistical weight, and selectively rejecting configurations with a small statistical weight. The algorithm leads to an efficient numerical determination of the solutions of the model and allows us to determine their qualitative behavior as a function of scale. We find that the moments of order n≤4 of the solutions of the model scale with the coarse-graining scale and that the scaling exponents are very close to the predictions of the Kolmogorov theory. The model qualitatively reproduces quite well the statistics concerning the local structure of the flow. However, we find that the model generally tends to predict an excess of strain compared to vorticity. Thus, our results show that while some physical aspects are not fully captured by the model, our approach leads to a very good description of several important qualitative properties of real turbulent flows.

  9. Unusual anatomy of maxillary central incisor with two roots

    OpenAIRE

    T S Ashwini Shivakumar; Saleem Makandar; Ajay Kadam

    2012-01-01

    Introduction: Knowledge of root canal morphology is essential for successful endodontic therapy. Failure to recognize unusual root canal anatomy may lead to unsuccessful endodontic treatment. Case Report: This case report describes the successful endodontic treatment of the maxillary central incisor with unusual anatomy of two roots and two root canals. A 23-year-old male patient was referred for dental consultation with discoloration of the maxillary right central incisor with periapical les...

  10. Statistical spatial properties of speckle patterns generated by multiple laser beams

    International Nuclear Information System (INIS)

    Le Cain, A.; Sajer, J. M.; Riazuelo, G.

    2011-01-01

    This paper investigates hot spot characteristics generated by the superposition of multiple laser beams. First, properties of speckle statistics are studied in the context of only one laser beam by computing the autocorrelation function. The case of multiple laser beams is then considered. In certain conditions, it is shown that speckles have an ellipsoidal shape. Analytical expressions of hot spot radii generated by multiple laser beams are derived and compared to numerical estimates made from the autocorrelation function. They are also compared to numerical simulations performed within the paraxial approximation. Excellent agreement is found for the speckle width as well as for the speckle length. Application to the speckle patterns generated in the Laser MegaJoule configuration in the zone where all the beams overlap is presented. Influence of polarization on the size of the speckles as well as on their abundance is studied.

  11. Effect of carboxymethylcellulose on the rheological and filtration properties of bentonite clay samples determined by experimental planning and statistical analysis

    Directory of Open Access Journals (Sweden)

    B. M. A. Brito

    Full Text Available Abstract Over the past few years, considerable research has been conducted using the techniques of mixture delineation and statistical modeling. Through this methodology, applications in various technological fields have been found/optimized, especially in clay technology, leading to greater efficiency and reliability. This work studied the influence of carboxymethylcellulose on the rheological and filtration properties of bentonite dispersions to be applied in water-based drilling fluids using experimental planning and statistical analysis for clay mixtures. The dispersions were prepared according to Petrobras standard EP-1EP-00011-A, which deals with the testing of water-based drilling fluid viscosifiers for oil prospecting. The clay mixtures were transformed into sodic compounds, and carboxymethylcellulose additives of high and low molar mass were added, in order to improve their rheology and filtrate volume. Experimental planning and statistical analysis were used to verify the effect. The regression models were calculated for the relation between the compositions and the following rheological properties: apparent viscosity, plastic viscosity, and filtrate volume. The significance and validity of the models were confirmed. The results showed that the 3D response surfaces of the compositions with high molecular weight carboxymethylcellulose added were the ones that most contributed to the rise in apparent viscosity and plastic viscosity, and that those with low molecular weight were the ones that most helped in the reduction of the filtrate volume. Another important observation is that the experimental planning and statistical analysis can be used as an important auxiliary tool to optimize the rheological properties and filtrate volume of bentonite clay dispersions for use in drilling fluids when carboxymethylcellulose is added.

  12. Xanthogranulomatous endometritis: an unusual pathological entity ...

    African Journals Online (AJOL)

    Xanthogranulomatous endometritis is an unusual pathological entity mimicking endometrial carcinoma. This shows sheets of foamy histiocytes alongwith other inflammatory cells. We, hereby, report a case of 45 year multigravida female with irregular menstrual history, clinically diagnosed as carcinoma and ...

  13. An unusual coexistence of Addison's disease and ...

    African Journals Online (AJOL)

    2013-07-17

    Jul 17, 2013 ... Case Study: An unusual coexistence of Addison's disease and phaeochromocytoma. 164 ... strongly positive. ... Department of Endocrinology and Metabolism, Ondokuz Mayis University Medical School, Samsun, Turkey.

  14. Cellular automata and statistical mechanical models

    International Nuclear Information System (INIS)

    Rujan, P.

    1987-01-01

    The authors elaborate on the analogy between the transfer matrix of usual lattice models and the master equation describing the time development of cellular automata. Transient and stationary properties of probabilistic automata are linked to surface and bulk properties, respectively, of restricted statistical mechanical systems. It is demonstrated that methods of statistical physics can be successfully used to describe the dynamic and the stationary behavior of such automata. Some exact results are derived, including duality transformations, exact mappings, disorder, and linear solutions. Many examples are worked out in detail to demonstrate how to use statistical physics in order to construct cellular automata with desired properties. This approach is considered to be a first step toward the design of fully parallel, probabilistic systems whose computational abilities rely on the cooperative behavior of their components

  15. Unusual temperature dependence of the magnetic moment in URu2Si2

    International Nuclear Information System (INIS)

    Faak, B.; Flouquet, J.; Lejay, P.

    1994-01-01

    The influence of the sample quality on the magnetic properties of the heavy-fermion superconductor URu 2 Si 2 has been studied by elastic neutron scattering. Two single crystals prepared under identical conditions received different heat treatments. The as-grown crystal shows an unusual temperature dependence of the magnetic Bragg peak intensity. The annealed sample behaves normally. The low-temperature magnetic moment is identical for the two samples, showing that the small moment of 0.023 (3) μ B is intrinsic. By varying the instrumental resolution, we show that the ordered moment as well as the limited correlation length (200-400 A) are of static origin. The finite correlation length appears related to defects. (author). 9 refs., 1 fig

  16. The rarity of "unusual" [corrected] dispositions of victim bodies: staging and posing.

    Science.gov (United States)

    Keppel, Robert D; Weis, Joseph G

    2004-11-01

    The act of leaving a victim's body in an unusual position is a conscious criminal action by an offender to thwart an investigation, shock the finder and investigators of the crime scene, or give perverted pleasure to the killer. The unusual position concepts of posing and staging a murder victim have been documented thoroughly and have been accepted by the courts as a definable phenomenon. One staging case and one posing case are outlined and reveal characteristics of those homicides. From the Washington State Attorney General's Homicide Investigation and Tracking System's database on murder covering the years 1981-2000 (a total of 5,224 cases), the relative frequency of unusual body dispositions is revealed as a very rare occurrence. Only 1.3% of victims are left in an unusual position, with 0.3% being posed and 0.1% being staged. The characteristics of these types of murders also set them apart: compared to all other murders, in staged murders the victims and killers are, on average, older. All victims and offenders in the staged murders are white, with victims being disproportionately white in murders with any kind of unusual body disposition. Likewise, females stand out as victims when the body is posed, staged, or left in other unusual positions. Whereas posed bodies are more likely to include sexual assault, often in serial murders, there is no evidence of either in the staged cases. Lastly, when a body is left in an unusual position, binding is more likely, as well as the use of more "hands on" means of killing the victim, such as stabbing or cutting weapons, bludgeons, ligatures, or hands and feet.

  17. Attitudes of Tourists about the Possibility of Development of Unusual Hotels in Serbia

    Directory of Open Access Journals (Sweden)

    Klisara Dubravka

    2015-01-01

    Full Text Available This paper deals with the problem of relatively young type of hotel that is increasingly attracting the attention of the modern tourist. Unusual hotels are very interesting phenomenon, not only for tourists and hospitality professionals, but also for people who are (currently out of the tourist flows. These are facilities with untypical architectural design, non-standard equipped or with services that are not common in the hospitality industry. They often contribute to the attractiveness of the area in which they are located. However, business sustainability of unusual hotels, as well as any other hotel, depends on guests, i.e. number of overnight stays.We present the results of research conducted among tourists in Serbia. The main task is to examined whether tourists are interested in the potential developing of unusual hotels. If so, which subtypes of unusual hotel would be best suited for the territory of Serbia. In order to compare experiences and operating results, parallel survey was conducted among owners of unusual hotels around the world. The results suggest a conclusion - with a favourable investment climate, unusual hotels should have a future in Serbia.

  18. Effects of thickness on the statistical properties of the Barkhausen noise in amorphous films

    Energy Technology Data Exchange (ETDEWEB)

    Santi, L. [Departamento de Fisica, Universidade Federal de Santa Maria, 97105-900, Santa Maria, RS (Brazil); Bohn, F. [Departamento de Fisica, Universidade Federal de Santa Maria, 97105-900, Santa Maria, RS (Brazil); Viegas, A.D.C. [Departamento de Fisica, Universidade Federal de Santa Maria, 97105-900, Santa Maria, RS (Brazil); Durin, G. [Istituto Elettrotecnico Nazionale Galileo Ferraris, Turin (Italy); Magni, A. [Istituto Elettrotecnico Nazionale Galileo Ferraris, Turin (Italy); Bonin, R. [Istituto Elettrotecnico Nazionale Galileo Ferraris, Turin (Italy); Zapperi, S. [Istituto dei Sistemi Complessi-CNR, Roma (Italy); Sommer, R.L. [Centro Brasileiro de Pesquisas Fisicas, 22290-180, Rio de Janeiro, RJ (Brazil)]. E-mail: sommer@cbpf.br

    2006-10-01

    The statistical properties of the Barkhausen noise (BN) in thin amorphous films are studied as a function of both the nominal composition and the thickness. BN was observed in single films with nominal compositions Fe{sub 73.5}Cu{sub 1}Nb{sub 3}Si{sub 22.5-x}B{sub x} (with x=4 and 9) in the thickness range 20nm-5{mu}m. The distributions of Barkhausen jump sizes and duration times were obtained and fitted to power laws with critical exponents {tau}=1.25+/-0.05 and {alpha}=1.60+/-0.05, respectively.

  19. An unusual foreign body of esophagus

    Directory of Open Access Journals (Sweden)

    Surinder K Singhal

    2010-07-01

    Full Text Available We report a rare case of an unusually long foreign body (Datun impacted in the esophagus of a 56 year-old gentleman. He was literate, without any psychiatric illness and had been using “Neem” (Azadirachta indica stick for cleaning his teeth for the past twenty years. Neem sticks are used for brushing teeth, perhaps one of the earliest and very effective dental care. On closer questioning he revealed his habit of passing the Neem stick into his throat with the aim of cleaning it too while cleaning his teeth. He presented to our emergency early in the morning with this strange long foreign body impacted in his esophagus which was removed successfully using a Jackson’s adult rigid oesophagoscope. We believe this to be the first case of such an unusually long foreign body to be reported in the literature.

  20. Generation of a Kind of Displaced Thermal States in the Diffusion Process and its Statistical Properties

    Science.gov (United States)

    Xiang-Guo, Meng; Hong-Yi, Fan; Ji-Suo, Wang

    2018-04-01

    This paper proposes a kind of displaced thermal states (DTS) and explores how this kind of optical field emerges using the entangled state representation. The results show that the DTS can be generated by a coherent state passing through a diffusion channel with the diffusion coefficient ϰ only when there exists κ t = (e^{\\hbar ν /kBT} - 1 )^{-1}. Also, its statistical properties, such as mean photon number, Wigner function and entropy, are investigated.

  1. Stabilization of actinides and lanthanides in unusually high oxidation states

    International Nuclear Information System (INIS)

    Eller, P.G.; Penneman, R.A.

    1986-01-01

    Chemical environments can be chosen which stabilize actinides and lanthanides in unusually high or low oxidation states and in unusual coordination. In many cases, one can rationalize the observed species as resulting from strong charge/size influences provided by specific sites in host lattices (e.g., Tb(IV) in BaTbO 3 or Am(IV) in polytungstate anions). In other cases, the unusual species can be considered from an acid-base viewpoint (e.g., U(III) in AsF 5 /HF solution or Pu(VII) in Li 5 PuO 6 ). In still other cases, an interplay of steric and redox effects can lead to interesting comparisons (e.g., instability of double fluoride salts of Pu(V) and Pu(VI) relative to U, Np, and Am analogues). Generalized ways to rationalize compounds containing actinides and lanthanides in unusual valences (particularly high valences), including the above and numerous other examples, will form the focus of this paper. Recently developed methods for synthesizing high valent f-element fluorides using superoxidizers and superacids at low temperatures will also be described. 65 refs., 8 figs., 9 tabs

  2. Statistical study of 22 K steel machanical properties

    International Nuclear Information System (INIS)

    Zhevanov, O.Ya.; Kolpishon, Eh.Yu.; Egorov, M.F.

    1988-01-01

    Test results of 100 specimens of 22 K steel are analyzed for determination of relation between the technology of production, structure and properties of steels. Mechanical properties (ultimate strength and yield strength, relative elongation, relative narrowing, impact strength, hardness) and structural parameters are considered. Investigation into the regressive dependence between mechanical properties and the diameter of the indentor mark when determining Brinell hardness have shown that it is advisable to replace the testing mechanical properties at static extension by the control of hardness and microstructure

  3. The Sedentary Multi-Frequency Survey. I. Statistical Identification and Cosmological Properties of HBL BL Lacs

    OpenAIRE

    Giommi, P.; Menna, M. T.; Padovani, P.

    1999-01-01

    We have assembled a multi-frequency database by cross-correlating the NVSS catalog of radio sources with the RASSBSC list of soft X-ray sources, obtaining optical magnitude estimates from the Palomar and UK Schmidt surveys as provided by the APM and COSMOS on-line services. By exploiting the nearly unique broad-band properties of High-Energy Peaked (HBL) BL Lacs we have statistically identified a sample of 218 objects that is expected to include about 85% of BL Lacs and that is therefore seve...

  4. Probable Unusual Transmission of Zika Virus

    Centers for Disease Control (CDC) Podcasts

    This podcast discusses a study about the probable unusual transmission of Zika Virus Infection from a scientist to his wife, published in the May 2011 issue of Emerging Infectious Diseases. Dr. Brian Foy, Associate Professor at Colorado State University, shares details of this event.

  5. Thermal and statistical properties of nuclei and nuclear systems

    International Nuclear Information System (INIS)

    Moretto, L.G.; Wozniak, G.J.

    1989-07-01

    The term statistical decay, statistical or thermodynamic equilibrium, thermalization, temperature, etc., have been used in nuclear physics since the introduction of the compound nucleus (CN) concept, and they are still used, perhaps even more frequently, in the context of intermediate- and high-energy heavy-ion reactions. Unfortunately, the increased popularity of these terms has not made them any clearer, and more often than not one encounters sweeping statements about the alleged statisticity of a nuclear process where the ''statistical'' connotation is a more apt description of the state of the speaker's mind than of the nuclear reaction. It is our goal, in this short set of lectures, to set at least some ideas straight on this broad and beautiful subject, on the one hand by clarifying some fundamental concepts, on the other by presenting some interesting applications to actual physical cases. 74 refs., 38 figs

  6. Ionization-potential depression and other dense plasma statistical property studies - Application to spectroscopic diagnostics.

    Science.gov (United States)

    Calisti, Annette; Ferri, Sandrine; Mossé, Caroline; Talin, Bernard

    2017-02-01

    The radiative properties of an emitter surrounded by a plasma, are modified through various mechanisms. For instance the line shapes emitted by bound-bound transitions are broadened and carry useful information for plasma diagnostics. Depending on plasma conditions the electrons occupying the upper quantum levels of radiators no longer exist as they belong to the plasma free electron population. All the charges present in the radiator environment contribute to the lowering of the energy required to free an electron in the fundamental state. This mechanism is known as ionization potential depression (IPD). The knowledge of IPD is useful as it affects both the radiative properties of the various ionic states and their populations. Its evaluation deals with highly complex n-body coupled systems, involving particles with different dynamics and attractive ion-electron forces. A classical molecular dynamics (MD) code, the BinGo-TCP code, has been recently developed to simulate neutral multi-component (various charge state ions and electrons) plasma accounting for all the charge correlations. In the present work, results on IPD and other dense plasma statistical properties obtained using the BinGo-TCP code are presented. The study focuses on aluminum plasmas for different densities and several temperatures in order to explore different plasma coupling conditions.

  7. Unusual Presentation of Maydl's Hernia

    African Journals Online (AJOL)

    Nikhil NBA, Natarajan K, Mohanty A, et al. An. Unusual Case of Maydl's Hernia. Int J Cur Res Rev. 2013;5(6):22-5. 11. Ganesaratnam M. Maydl's hernia: Report of a Series of Seven Cases and Review of Literature. Brit J Surg. 1985;72:737-8. 12. Weledji EP, Mokake M, Ngowe MN. A Rare. Presentation of Maydl's Hernia.

  8. Unusual lightning electric field waveforms observed in Kathmandu, Nepal, and Uppsala, Sweden

    Science.gov (United States)

    Adhikari, Pitri Bhakta; Sharma, Shriram; Baral, Kedarnath; Rakov, Vladimir A.

    2017-11-01

    Unusual lightning events have been observed in Uppsala, Sweden, and Kathmandu, Nepal, using essentially the same electric field measuring system developed at Uppsala University. They occurred in the storms that also generated ;normal; lightning events. The unusual events recorded in Uppsala occurred on one thunderstorm day. Similar events were observed in Kathmandu on multiple thunderstorm days. The unusual events were analyzed in this study assuming them to be positive ground flashes (+CGs), although we cannot rule out the possibility that some or most of them were actually cloud discharges (ICs). The unusual events were each characterized by a relatively slow, negative (atmospheric electricity sign convention) electric field waveform preceded by a pronounced opposite-polarity pulse whose duration was some tens of microseconds. To the best of our knowledge, such unusual events have not been reported in the literature. The average amplitudes of the opposite-polarity pulses with respect to those of the following main waveform were found to be about 33% in Uppsala (N = 31) and about 38% in Kathmandu (N = 327). The average durations of the main waveform and the preceding opposite-polarity pulse in Uppsala were 8.24 ms and 57.1 μs, respectively, and their counterparts in Kathmandu were 421 μs and 39.7 μs. Electric field waveforms characteristic of negative ground flashes (-CGs) were also observed, and none of them exhibited an opposite-polarity pulse prior to the main waveform. Possible origins of the unusual field waveforms are discussed.

  9. NPP unusual events: data, analysis and application

    International Nuclear Information System (INIS)

    Tolstykh, V.

    1990-01-01

    Subject of the paper are the IAEA cooperative patterns of unusual events data treatment and utilization of the operating safety experience feedback. The Incident Reporting System (IRS) and the Analysis of Safety Significant Event Team (ASSET) are discussed. The IRS methodology in collection, handling, assessment and dissemination of data on NPP unusual events (deviations, incidents and accidents) occurring during operations, surveillance and maintenance is outlined by the reports gathering and issuing practice, the experts assessment procedures and the parameters of the system. After 7 years of existence the IAEA-IRS contains over 1000 reports and receives 1.5-4% of the total information on unusual events. The author considers the reports only as detailed technical 'records' of events requiring assessment. The ASSET approaches implying an in-depth occurrences analysis directed towards level-1 PSA utilization are commented on. The experts evaluated root causes for the reported events and some trends are presented. Generally, internal events due to unexpected paths of water in the nuclear installations, occurrences related to the integrity of the primary heat transport systems, events associated with the engineered safety systems and events involving human factor represent the large groups deserving close attention. Personal recommendations on how to use the events related information use for NPP safety improvement are given. 2 tabs (R.Ts)

  10. Statistical correlations in an ideal gas of particles obeying fractional exclusion statistics.

    Science.gov (United States)

    Pellegrino, F M D; Angilella, G G N; March, N H; Pucci, R

    2007-12-01

    After a brief discussion of the concepts of fractional exchange and fractional exclusion statistics, we report partly analytical and partly numerical results on thermodynamic properties of assemblies of particles obeying fractional exclusion statistics. The effect of dimensionality is one focal point, the ratio mu/k_(B)T of chemical potential to thermal energy being obtained numerically as a function of a scaled particle density. Pair correlation functions are also presented as a function of the statistical parameter, with Friedel oscillations developing close to the fermion limit, for sufficiently large density.

  11. Chalk: composition, diagenesis and physical properties

    DEFF Research Database (Denmark)

    Fabricius, Ida Lykke

    2007-01-01

    Chalk is a sedimentary rock of unusually high homogeneity on the scale where physical properties are measured, but the properties fall in wide ranges. Chalk may thus be seen as the ideal starting point for a physical understanding of rocks in general. Properties as porosity, permeability, capillary...... involving clay, silica, and calcite are interlinked, but progress differently in different localities. This partly depends on primary sediment composition, including organic content, which may induce the formation of concretions by microbial action. The diagenetic processes also depend on water depth, rate...

  12. Unusual Cancers of the Head and Neck

    Science.gov (United States)

    ... more information). Unusual Cancers of the Head and Neck Nasopharyngeal Cancer See the PDQ summary on Childhood ... of PDQ documents can be used freely as text. It cannot be identified as an NCI PDQ ...

  13. Probing the statistical properties of Anderson localization with quantum emitters

    International Nuclear Information System (INIS)

    Smolka, Stephan; Thyrrestrup, Henri; Sapienza, Luca; Lehmann, Tau B; Rix, Kristian R; GarcIa, Pedro D; Lodahl, Peter; Froufe-Perez, Luis S

    2011-01-01

    Wave propagation in disordered media can be strongly modified by multiple scattering and wave interference. Ultimately, the so-called Anderson-localized regime is reached when the waves become strongly confined in space. So far, Anderson localization of light has been probed in transmission experiments by measuring the intensity of an external light source after propagation through a disordered medium. However, discriminating between Anderson localization and losses in these experiments remains a major challenge. In this paper, we present an alternative approach where we use quantum emitters embedded in disordered photonic crystal waveguides as light sources. Anderson-localized modes are efficiently excited and the analysis of the photoluminescence spectra allows us to explore their statistical properties, for example the localization length and average loss length. With increasing the amount of disorder induced in the photonic crystal, we observe a pronounced increase in the localization length that is attributed to changes in the local density of states, a behavior that is in stark contrast to entirely random systems. The analysis may pave the way for accurate models and the control of Anderson localization in disordered photonic crystals.

  14. Precipitation in a boiling soup: is microphysics driving the statistical properties of intense turbulent convection?

    Science.gov (United States)

    Parodi, A.; von Hardenberg, J.; Provenzale, A.

    2012-04-01

    Intense precipitation events are often associated with strong convective phenomena in the atmosphere. A deeper understanding of how microphysics affects the spatial and temporal variability of convective processes is relevant for many hydro-meteorological applications, such as the estimation of rainfall using remote sensing techniques and the ability to predict severe precipitation processes. In this paper, high-resolution simulations (0.1-1 km) of an atmosphere in radiative-convective equilibrium are performed using the Weather Research and Forecasting (WRF) model by prescribing different microphysical parameterizations. The dependence of fine-scale spatio-temporal properties of convective structures on microphysical details are investigated and the simulation results are compared with the known properties of radar maps of precipitation fields. We analyze and discuss similarities and differences and, based also on previous results on the dependence of precipitation statistics on the raindrop terminal velocity, try to draw some general inferences.

  15. Unusual presentation of perirenal lung metastases

    International Nuclear Information System (INIS)

    D'Souza, D.L.; Heinze, S.B.; Dowling, R.J.

    2006-01-01

    Lung cancer is not commonly known to metastasise to the perirenal space, with only five such cases previously published. We present an unusual case of perirenal lung metastases manifesting as diffuse perinephric stranding which to our knowledge has not been described before Copyright (2006) Blackwell Publishing Asia Pty Ltd

  16. The Statistical Properties of Host Load

    Directory of Open Access Journals (Sweden)

    Peter A. Dinda

    1999-01-01

    Full Text Available Understanding how host load changes over time is instrumental in predicting the execution time of tasks or jobs, such as in dynamic load balancing and distributed soft real‐time systems. To improve this understanding, we collected week‐long, 1 Hz resolution traces of the Digital Unix 5 second exponential load average on over 35 different machines including production and research cluster machines, compute servers, and desktop workstations. Separate sets of traces were collected at two different times of the year. The traces capture all of the dynamic load information available to user‐level programs on these machines. We present a detailed statistical analysis of these traces here, including summary statistics, distributions, and time series analysis results. Two significant new results are that load is self‐similar and that it displays epochal behavior. All of the traces exhibit a high degree of self‐similarity with Hurst parameters ranging from 0.73 to 0.99, strongly biased toward the top of that range. The traces also display epochal behavior in that the local frequency content of the load signal remains quite stable for long periods of time (150–450 s mean and changes abruptly at epoch boundaries. Despite these complex behaviors, we have found that relatively simple linear models are sufficient for short‐range host load prediction.

  17. Structure and properties during aging of an ultra-high strength Al-Cu-Li-Ag-Mg alloy

    Science.gov (United States)

    Gayle, Frank W.; Heubaum, Frank H.; Pickens, Joseph R.

    1990-01-01

    The structure and properties of the strengthening phases formed during aging in an Al-Cu-Li-Ag-Mg alloy (Weldalite 049) were elulcidated, by following the development of the microstructure by means of TEM. The results of observations showed that the Weldalite 049 alloy has a series of unusual and technologically useful combinations of mechanical properties in different aging conditions, such as natural aging without prior cold work to produce high strengths, a reversion temper of lower yield strength and unusually high ductility, a room temperature reaging of the reversion temper eventually leading to the original T4 hardness, and ultrahigh-strength T6 properties.

  18. Statistical Physics

    CERN Document Server

    Mandl, Franz

    1988-01-01

    The Manchester Physics Series General Editors: D. J. Sandiford; F. Mandl; A. C. Phillips Department of Physics and Astronomy, University of Manchester Properties of Matter B. H. Flowers and E. Mendoza Optics Second Edition F. G. Smith and J. H. Thomson Statistical Physics Second Edition E. Mandl Electromagnetism Second Edition I. S. Grant and W. R. Phillips Statistics R. J. Barlow Solid State Physics Second Edition J. R. Hook and H. E. Hall Quantum Mechanics F. Mandl Particle Physics Second Edition B. R. Martin and G. Shaw The Physics of Stars Second Edition A. C. Phillips Computing for Scient

  19. QSPR Study of the Retention/release Property of Odorant Molecules in Water Using Statistical Methods

    Directory of Open Access Journals (Sweden)

    Assia Belhassan

    2017-10-01

    Full Text Available An integrated approach physicochemistry and structures property relationships has been carried out to study the odorant molecules retention/release phenomenon in the water. This study aimed to identify the molecular properties (molecular descriptors that govern this phenomenon assuming that modifying the structure leads automatically to a change in the retention/release property of odorant molecules. ACD/ChemSketch, MarvinSketch, and ChemOffice programs were used to calculate several molecular descriptors of 51 odorant molecules (15 alcohols, 11 aldehydes, 9 ketones and 16 esters. A total of 37 molecules (2/3 of the data set were placed in the training set to build the QSPR models, whereas the remaining, 14 molecules (1/3 of the data set constitute the test set. The best descriptors were selected to establish the quantitative structure property relationship (QSPR of the retention/release property of odorant molecules in water using multiple linear regression (MLR, multiple non-linear regression (MNLR and an artificial neural network (ANN methods. We propose a quantitative model according to these analyses. The models were used to predict the retention/release property of the test set compounds, and agreement between the experimental and predicted values was verified. The descriptors showed by QSPR study are used for study and designing of new compounds. The statistical results indicate that the predicted values are in good agreement with the experimental results. To validate the predictive power of the resulting models, external validation multiple correlation coefficient was calculated and has both in addition to a performant prediction power, a favorable estimation of stability. DOI: http://dx.doi.org/10.17807/orbital.v9i4.978 

  20. Properties of incident reporting systems in relation to statistical trend and pattern analysis

    International Nuclear Information System (INIS)

    Kalfsbeek, H.W.; Arsenis, S.P.

    1990-01-01

    This paper describes the properties deemed desirable for an incident reporting system in order to render it useful for extracting valid statistical trend and pattern information. The perspective under which a data collection system is seen in this paper is the following: data are essentially gathered on a set of variables describing an event or incident (the items featuring on a reporting format) in order to learn about (multiple) dependencies (called interactions) between these variables. Hence, the necessary features of the data source are highlighted and potential problem sources limiting the validity of the results to be obtained are identified. In this frame, important issues are the reporting completeness, related to the reporting criteria and reporting frequency, and of course the reporting contents and quality. The choice of the report items (the variables) and their categorization (code dictionary) may influence (bias) the insights gained from trend and pattern analyses, as may the presence or absence of a structure for correlating the reported issues within an incident. The issues addressed in this paper are brought in relation to some real world reporting systems on safety related events in Nuclear Power Plants, so that their possibilities and limitations with regard to statistical trend and pattern analysis become manifest

  1. Unusual negative magnetoresistance in Bi2Se3-ySy topological insulator under perpendicular magnetic field

    Science.gov (United States)

    Singh, Rahul; Gangwar, Vinod K.; Daga, D. D.; Singh, Abhishek; Ghosh, A. K.; Kumar, Manoranjan; Lakhani, A.; Singh, Rajeev; Chatterjee, Sandip

    2018-03-01

    The magneto-transport properties of Bi2Se3-ySy were investigated. Magnetoresistance (MR) decreases with an increase in the S content, and finally, for 7% (i.e., y = 0.21) S doping, the magnetoresistance becomes negative. This negative MR is unusual as it is observed when a magnetic field is applied in the perpendicular direction to the plane of the sample. The magneto-transport behavior shows the Shubnikov-de Haas (SdH) oscillation, indicating the coexistence of surface and bulk states. The negative MR has been attributed to the non-trivial bulk conduction.

  2. Some statistical properties of strange attractors: engineering view

    International Nuclear Information System (INIS)

    Mijangos, M; Kontorovich, V; Aguilar-Torrentera, J

    2008-01-01

    In this paper, the statistical characterization of strange attractors is investigated via the so-called 'model distribution' approach. It is shown that in order to calculate the first four cumulants, which are necessary to create a model distribution of kurtosis approximation, a systematic method for the calculus of the variance needs to be considered. Correspondently, an analytical method based on the Kolmogorov-Sinai (K-S) entropy for variance approximation is herein proposed. The methodology is of interest for its application in the statistical analysis of chaotic systems that model physical phenomena found in some areas of electrical (communication) engineering

  3. Thermodynamics, Gibbs Method and Statistical Physics of Electron Gases Gibbs Method and Statistical Physics of Electron Gases

    CERN Document Server

    Askerov, Bahram M

    2010-01-01

    This book deals with theoretical thermodynamics and the statistical physics of electron and particle gases. While treating the laws of thermodynamics from both classical and quantum theoretical viewpoints, it posits that the basis of the statistical theory of macroscopic properties of a system is the microcanonical distribution of isolated systems, from which all canonical distributions stem. To calculate the free energy, the Gibbs method is applied to ideal and non-ideal gases, and also to a crystalline solid. Considerable attention is paid to the Fermi-Dirac and Bose-Einstein quantum statistics and its application to different quantum gases, and electron gas in both metals and semiconductors is considered in a nonequilibrium state. A separate chapter treats the statistical theory of thermodynamic properties of an electron gas in a quantizing magnetic field.

  4. Semi-Poisson statistics in quantum chaos.

    Science.gov (United States)

    García-García, Antonio M; Wang, Jiao

    2006-03-01

    We investigate the quantum properties of a nonrandom Hamiltonian with a steplike singularity. It is shown that the eigenfunctions are multifractals and, in a certain range of parameters, the level statistics is described exactly by semi-Poisson statistics (SP) typical of pseudointegrable systems. It is also shown that our results are universal, namely, they depend exclusively on the presence of the steplike singularity and are not modified by smooth perturbations of the potential or the addition of a magnetic flux. Although the quantum properties of our system are similar to those of a disordered conductor at the Anderson transition, we report important quantitative differences in both the level statistics and the multifractal dimensions controlling the transition. Finally, the study of quantum transport properties suggests that the classical singularity induces quantum anomalous diffusion. We discuss how these findings may be experimentally corroborated by using ultracold atoms techniques.

  5. salmonella typhi spondyutis: an unusual presentation

    African Journals Online (AJOL)

    It was relieved by lying flat. She had pre- viously been admitted to King Edward VIII Hospital in. May 1969 with a cough, chest and abdominal pain, ... foot and cranium may be the sites of skeletal involvement. Our case shows several unusual features. Sickle-cell anaemia and haemoglobinopathy were absent. Although.

  6. Unusual Cutaneous Manifestation of Tuberous Sclerosis

    Directory of Open Access Journals (Sweden)

    K C Shah

    1980-01-01

    Full Text Available Cutaneous manifestations are found in 60 to 70% cases of tuberous sclerosis and consist of adenoma sebaceum, periungual fibromatas, cafe au lait spots, shagreen patches and white macules. Our patient showed unusual skin manifestations like spotty pigmentation on the chest, back and abdomen and hyperkeratosis palmaris et plantaris.

  7. Log-concave Probability Distributions: Theory and Statistical Testing

    DEFF Research Database (Denmark)

    An, Mark Yuing

    1996-01-01

    This paper studies the broad class of log-concave probability distributions that arise in economics of uncertainty and information. For univariate, continuous, and log-concave random variables we prove useful properties without imposing the differentiability of density functions. Discrete...... and multivariate distributions are also discussed. We propose simple non-parametric testing procedures for log-concavity. The test statistics are constructed to test one of the two implicati ons of log-concavity: increasing hazard rates and new-is-better-than-used (NBU) property. The test for increasing hazard...... rates are based on normalized spacing of the sample order statistics. The tests for NBU property fall into the category of Hoeffding's U-statistics...

  8. Studies in the statistical and thermal properties of hadronic matter under some extreme conditions

    International Nuclear Information System (INIS)

    Chase, K.C.; Mekjian, A.Z.; Bhattacharyya, P.

    1997-01-01

    The thermal and statistical properties of hadronic matter under some extreme conditions are investigated using an exactly solvable canonical ensemble model. A unified model describing both the fragmentation of nuclei and the thermal properties of hadronic matter is developed. Simple expressions are obtained for quantities such as the hadronic equation of state, specific heat, compressibility, entropy, and excitation energy as a function of temperature and density. These expressions encompass the fermionic aspect of nucleons, such as degeneracy pressure and Fermi energy at low temperatures and the ideal gas laws at high temperatures and low density. Expressions are developed which connect these two extremes with behavior that resembles an ideal Bose gas with its associated Bose condensation. In the thermodynamic limit, an infinite cluster exists below a certain critical condition in a manner similar to the sudden appearance of the infinite cluster in percolation theory. The importance of multiplicity fluctuations is discussed and some recent data from the EOS collaboration on critical point behavior of nuclei can be accounted for using simple expressions obtained from the model. copyright 1997 The American Physical Society

  9. Fundamentals of statistics

    CERN Document Server

    Mulholland, Henry

    1968-01-01

    Fundamentals of Statistics covers topics on the introduction, fundamentals, and science of statistics. The book discusses the collection, organization and representation of numerical data; elementary probability; the binomial Poisson distributions; and the measures of central tendency. The text describes measures of dispersion for measuring the spread of a distribution; continuous distributions for measuring on a continuous scale; the properties and use of normal distribution; and tests involving the normal or student's 't' distributions. The use of control charts for sample means; the ranges

  10. Unusual causes of mechanical small bowel obstruction

    International Nuclear Information System (INIS)

    Shatnawi, Nawaf J.; Bani-Hani, Kamal E.

    2005-01-01

    We herein report our experience regarding unusual causes of bowel obstruction to increase the awareness of surgeons regarding this disease. From 1991 to 2003, we had experience at the University affiliated hospitals, northern Jordan with 24 patients with small bowel obstruction resulting from unusual causes. We retrospectively reviewed the medical records of these patients with regards to the mode of presentation, cause of obstruction, radiological and operative findings, management and outcome. We recorded 15 patients who underwent previous abdominal surgery. Preoperative diagnosis was correct in only one patient with an internal hernia, but the abdominal CT scan suggested the diagnosis in 5 of the 9 patients who had the scan. The final diagnosis was internal hernias in 11 patients, foreign bodies in 5, ischemic strictures in 3, carcinoid tumors in 2, endometriosis in 2, and metastatic deposit from interstitial bladder carcinoma in one patient. Nine of the 12 patients with recurrent obstruction had either short course or recurrence obstruction during the same hospital admission. W carried out bowel resections in 15 patients (5 resections were due to bowel strangulation). Post operative death occurred in 4 patients. Awareness of these rare causes of intestinal obstruction even in patients with previous abdominal operation might improve the outcome. The tentative diagnosis of adhesion obstruction in patients with unusual obstructive etiology might lead to a higher rate of gangrenous complications. Rigorous preoperative evaluation including careful history and early abdominal CT may show the obstructive cause. (author)

  11. Magnetic vortex excitation as spin torque oscillator and its unusual trajectories

    Science.gov (United States)

    Natarajan, Kanimozhi; Muthuraj, Ponsudana; Rajamani, Amuda; Arumugam, Brinda

    2018-05-01

    We report an interesting observation of unusual trajectories of vortex core oscillations in a spin valve pillar. Micromagnetic simulation in the composite free layer spin valve nano-pillar shows magnetic vortex excitation under critical current density. When current density is slightly increased and wave vector is properly tuned, for the first time we observe a star like and square gyration. Surprisingly this star like and square gyration also leads to steady, coherent and sustained oscillations. Moreover, the frequency of gyration is also very high for this unusual trajectories. The power spectral analysis reveals that there is a marked increase in output power and frequency with less distortions. Our investigation explores the possibility of these unusual trajectories to exhibit spin torque oscillations.

  12. No Laughing Matter: Gelastic Migraine and Other Unusual Headache Syndromes.

    Science.gov (United States)

    Mathew, Paul G; Robertson, Carrie E

    2016-05-01

    Primary and secondary headache disorders have established diagnostic criteria in the International Classification of Headache Disorders IIIb, as well as classic findings, which although not part of the formal criteria are often suggestive of a particular diagnosis. At times, headache disorders can involve unusual symptoms that lack an identifiable secondary cause. This review will discuss some of these unusual symptoms, including headache associated auditory and olfactory symptoms, as well as two case reports involving gelastic migraine and migrainous thoracalgia.

  13. Escherichia coli photoreactivating enzyme: purification and properties

    International Nuclear Information System (INIS)

    Snapka, R.M.; Sutherland, B.M.

    1980-01-01

    Researchers have purified large quantities of Escherichia coli photoreactivating enzyme to apparent homogeneity and have studied its physical and chemical properties. The enzyme has a molecular weight of 36,800 and a S/sub 20,w/ 0 of 3.72 S. Amino acid analysis revealed an apparent absence of tryptophan, a low content of aromatic residues, and the presence of no unusual amino acids. The N terminus is arginine. The purified enzyme contained up to 13% carbohydrate by weight. The carbohydrate was composed of mannose, galactose, glucose, and N-acetylglucosamine. The enzyme is also associated with RNA containing uracil, adenine, guanine, and cytosine with no unusual bases detected

  14. A social network's changing statistical properties and the quality of human innovation

    Energy Technology Data Exchange (ETDEWEB)

    Uzzi, Brian [Kellogg School of Management, Northwestern University, Evanston, IL (United States)], E-mail: uzzi@northwestern.edu

    2008-06-06

    We examined the entire network of creative artists that made Broadway musicals, in the post-War period, a collaboration network of international acclaim and influence, with an eye to investigating how the network's structural features condition the relationship between individual artistic talent and the success of their musicals. Our findings show that some of the evolving topographical qualities of degree distributions, path lengths and assortativity are relatively stable with time even as collaboration patterns shift, which suggests their changes are only minimally associated with the ebb and flux of the success of new productions. In contrast, the clustering coefficient changed substantially over time and we found that it had a nonlinear association with the production of financially and artistically successful shows. When the clustering coefficient ratio is low or high, the financial and artistic success of the industry is low, while an intermediate level of clustering is associated with successful shows. We supported these findings with sociological theory on the relationship between social structure and collaboration and with tests of statistical inference. Our discussion focuses on connecting the statistical properties of social networks to their performance and the performance of the actors embedded within them.

  15. Statistical properties of solar flares and coronal mass ejections through the solar cycle

    International Nuclear Information System (INIS)

    Telloni, Daniele; Antonucci, Ester; Carbone, Vincenzo; Lepreti, Fabio

    2016-01-01

    Waiting Time Distributions (WTDs) of solar flares are investigated all through the solar cycle. The same approach applied to Coronal Mass Ejections (CMEs) in a previous work is considered here for flare occurrence. Our analysis reveals that flares and CMEs share some common statistical properties, which result dependent on the level of solar activity. Both flares and CMEs seem to independently occur during minimum solar activity phases, whilst their WTDs significantly deviate from a Poisson function at solar maximum, thus suggesting that these events are correlated. The characteristics of WTDs are constrained by the physical processes generating those eruptions associated with flares and CMEs. A scenario may be drawn in which different mechanisms are actively at work during different phases of the solar cycle. Stochastic processes, most likely related to random magnetic reconnections of the field lines, seem to play a key role during solar minimum periods. On the other hand, persistent processes, like sympathetic eruptions associated to the variability of the photospheric magnetism, are suggested to dominate during periods of high solar activity. Moreover, despite the similar statistical properties shown by flares and CMEs, as it was mentioned above, their WTDs appear different in some aspects. During solar minimum periods, the flare occurrence randomness seems to be more evident than for CMEs. Those persistent mechanisms generating interdependent events during maximum periods of solar activity can be suggested to play a more important role for CMEs than for flares, thus mitigating the competitive action of the random processes, which seem instead strong enough to weaken the correlations among flare event occurrence during solar minimum periods. However, it cannot be excluded that the physical processes at the basis of the origin of the temporal correlation between solar events are different for flares and CMEs, or that, more likely, more sophisticated effects are

  16. Statistical aspects of determinantal point processes

    DEFF Research Database (Denmark)

    Lavancier, Frédéric; Møller, Jesper; Rubak, Ege

    The statistical aspects of determinantal point processes (DPPs) seem largely unexplored. We review the appealing properties of DDPs, demonstrate that they are useful models for repulsiveness, detail a simulation procedure, and provide freely available software for simulation and statistical infer...

  17. Unusual Metastases in Renal Cell Carcinoma: A Single Institution Experience and Review of Literature

    Science.gov (United States)

    Villarreal-Garza, Cynthia; Perez-Alvarez, Sandra I.; Gonzalez-Espinoza, Ivan R.; Leon-Rodriguez, Eucario

    2010-01-01

    Background To report location and management of atypical metastases from renal cell carcinoma (RCC) in the Instituto Nacional de Ciencias Medicas e Investigacion Salvador Zubiran (INCMNSZ) in Mexico City. Methods Between 1987 to 2009, 545 patients with RCC were retrospectively identified at the INCMNSZ. Patients with unusual metastases confirmed by histopathology were analyzed. Epidemiological, clinical, diagnosis, treatment and outcome data were reviewed. Results Sixty patients developed 98 unusual metastases secondary to RCC. The group was comprised of 35 men (58.3%), with a median age of 60 years at diagnosis. Metachronous unusual metastases with primary renal cancer were observed in 37 individuals (61.7%). Median time from primary RCC diagnosis to the first unusual metastasis was 16.5 months. Median survival from diagnosis of the first unusual metastasis to death was 5.0 months (CI 95%: 2.8-7.2 months). Patients with an initial solitary metastatic lesion in an unusual site (28.3%) had a better survival compared to patients who primarily presented with multiple metastases, 17.0 (CI 95%: 6.1-27.9) Vs 3.0 months (CI 95%: 0.9-5.1), p = 0.001. Unusual metastasis resection (21 patients) improved survival, 25.0 (CI 95%: 5.1-44.9) Vs 3.0 months (CI 95%: 0.8-5.2), p < 0.0001. No survival difference was observed between localization of unsual metastases (p = 0.72). Conclusions In patients with advanced RCC we suggest an individual diagnostic and surgical approach to achieve complete resection with disease-free margins, even in the presence of unusual metastatic sites, multifocality, or history of metastasectomy. These strategy might provide not only palliation for symptoms, but an opportunity for meaningful disease free and overall survival. PMID:29147198

  18. Normothermic thyroid storm: an unusual presentation

    Science.gov (United States)

    Sabir, Anas Ahmad; Sada, Kabiru; Yusuf, Bashir O.; Aliyu, Idris

    2016-01-01

    Thyroid storm is a rare life-threatening emergency due to thyrotoxicosis. A 30-year-old female presented with restlessness, tachycardia and vomiting but with normothermia which is an unusual presentation. There is the need for clinicians to be aware of atypical clinical features that can make the diagnosis of thyroid storm difficult. PMID:27540465

  19. Statistical methods and materials characterisation

    International Nuclear Information System (INIS)

    Wallin, K.R.W.

    2010-01-01

    Statistics is a wide mathematical area, which covers a myriad of analysis and estimation options, some of which suit special cases better than others. A comprehensive coverage of the whole area of statistics would be an enormous effort and would also be outside the capabilities of this author. Therefore, this does not intend to be a textbook on statistical methods available for general data analysis and decision making. Instead it will highlight a certain special statistical case applicable to mechanical materials characterization. The methods presented here do not in any way rule out other statistical methods by which to analyze mechanical property material data. (orig.)

  20. QSPR study of the retention/release property of odorant molecules in pectin gels using statistical methods

    Directory of Open Access Journals (Sweden)

    Assia Belhassan

    2017-11-01

    Full Text Available The ACD/ChemSketch, MarvinSketch, and ChemOffice programmes were used to calculate several molecular descriptors of 51 odorant molecules (15 alcohols, 11 aldehydes, 9 ketones and 16 esters. The best descriptors were selected to establish the Quantitative Structure-Property Relationship (QSPR of the retention/release property of odorant molecules in pectin gels using Principal Components Analysis (PCA, Multiple Linear Regression (MLR, Multiple Non-linear Regression (MNLR and Artificial Neural Network (ANN methods We propose a quantitative model based on these analyses. PCA has been used to select descriptors that exhibit high correlation with the retention/release property. The MLR method yielded correlation coefficients of 0.960 and 0.958 for PG-0.4 (pectin concentration: 0.4% w/w and PG-0.8 (pectin concentration: 0.8% w/w media, respectively. Internal and external validations were used to determine the statistical quality of the QSPR of the two MLR models. The MNLR method, considering the relevant descriptors obtained from the MLR, yielded correlation coefficients of 0.978 and 0.975 for PG-0.4 and PG-0.8 media, respectively. The applicability domain of MLR models was investigated using simple and leverage approaches to detect outliers and outside compounds. The effects of different descriptors on the retention/release property are described, and these descriptors were used to study and design new compounds with higher and lower values of the property than the existing ones. Keywords: Odorant Molecules, Retention/Release, Pectin Gels, Quantitative Structure Property Relationship, Multiple Linear Regression, Artificial Neural Network

  1. Identifying clusters of active transportation using spatial scan statistics.

    Science.gov (United States)

    Huang, Lan; Stinchcomb, David G; Pickle, Linda W; Dill, Jennifer; Berrigan, David

    2009-08-01

    There is an intense interest in the possibility that neighborhood characteristics influence active transportation such as walking or biking. The purpose of this paper is to illustrate how a spatial cluster identification method can evaluate the geographic variation of active transportation and identify neighborhoods with unusually high/low levels of active transportation. Self-reported walking/biking prevalence, demographic characteristics, street connectivity variables, and neighborhood socioeconomic data were collected from respondents to the 2001 California Health Interview Survey (CHIS; N=10,688) in Los Angeles County (LAC) and San Diego County (SDC). Spatial scan statistics were used to identify clusters of high or low prevalence (with and without age-adjustment) and the quantity of time spent walking and biking. The data, a subset from the 2001 CHIS, were analyzed in 2007-2008. Geographic clusters of significantly high or low prevalence of walking and biking were detected in LAC and SDC. Structural variables such as street connectivity and shorter block lengths are consistently associated with higher levels of active transportation, but associations between active transportation and socioeconomic variables at the individual and neighborhood levels are mixed. Only one cluster with less time spent walking and biking among walkers/bikers was detected in LAC, and this was of borderline significance. Age-adjustment affects the clustering pattern of walking/biking prevalence in LAC, but not in SDC. The use of spatial scan statistics to identify significant clustering of health behaviors such as active transportation adds to the more traditional regression analysis that examines associations between behavior and environmental factors by identifying specific geographic areas with unusual levels of the behavior independent of predefined administrative units.

  2. The unusual practices within some Neo-Pentecostal churches in South Africa: Reflections and recommendations

    Directory of Open Access Journals (Sweden)

    Mookgo S. Kgatle

    2017-09-01

    Full Text Available This article reflects and makes recommendations on the recent unusual practices within some Neo-Pentecostal churches in South Africa. Neo-Pentecostal churches in South Africa refer to churches that have crossed denominational boundaries. These churches idolise the miraculous, healing, deliverance and enactment of bizarre church performances often performed by charismatic and highly influential spiritual leaders. There have been unusual practices within some Neo-Pentecostal churches that include, among others, the eating of grass, eating of snakes, drinking of petrol, spraying of Doom on the congregants and other experiences. There are many possible theological, psychological and socio-economic explanations for these unusual practices. Given the facts that many South Africans experience various socio-economic challenges, it is argued here that the socio-economic factor is the main explanation for the support of these unusual practices. The unusual practices within some Neo-Pentecostal churches in South Africa are critically unpacked by looking at various churches where the incidents happened. The possible theological, psychological and socio-economic explanations for such practices are outlined in detail. Recommendations are made based on the scientific findings on the unusual practices.

  3. Spectroscopic investigation of the redox properties of CoAPO molecular sieves

    NARCIS (Netherlands)

    Peeters, M.P.J.; Hooff, van J.H.C.; Sheldon, R.A.; Zholobenko, V.L.; Kustov, L.M.; Kazansky, V.B.; Balmoos, von R.; Higgins, J.B.; Treacy, M.M.J

    1993-01-01

    Acid sites in CoAPO-5 and CoAPO-11 and redox properties of these Co-substituted aluminophosphates have been investigated using UV- and IR-spectroscopy. The data obtained show that CoAPO exhibits quite unusual acidic and redox properties. The absence of the bridged OH-group seems to be a common

  4. Modern applied U-statistics

    CERN Document Server

    Kowalski, Jeanne

    2008-01-01

    A timely and applied approach to the newly discovered methods and applications of U-statisticsBuilt on years of collaborative research and academic experience, Modern Applied U-Statistics successfully presents a thorough introduction to the theory of U-statistics using in-depth examples and applications that address contemporary areas of study including biomedical and psychosocial research. Utilizing a "learn by example" approach, this book provides an accessible, yet in-depth, treatment of U-statistics, as well as addresses key concepts in asymptotic theory by integrating translational and cross-disciplinary research.The authors begin with an introduction of the essential and theoretical foundations of U-statistics such as the notion of convergence in probability and distribution, basic convergence results, stochastic Os, inference theory, generalized estimating equations, as well as the definition and asymptotic properties of U-statistics. With an emphasis on nonparametric applications when and where applic...

  5. Giant seborrheic keratosis of the face – an unusual presentation

    Directory of Open Access Journals (Sweden)

    Koh Khai Luen

    2016-04-01

    Full Text Available Seborrheic keratosis is the most common benign epidermal lesion in the world, especially among the elderly. Its inherent benign nature has precluded the need to remove it for medical reasons. Most of the concerns presented to dermatologists or plastic surgeons are of cosmetic reasons, besides some unusual appearances that necessitate cutaneous malignancy evaluation. Unusually large sizes of seborrheic keratosis are rarely reported, and its clinical significance is largely unknown. It has been proven by recent molecular studies that seborrheic keratosis is true neoplasia rather than a mere epidermal hyperplasia, and various authors have reported several cases of concomitant malignancy arising from seborrheic keratosis. Plastic surgeon expertise is often required when faced with an extensive lesion, requiring reconstructive procedures to preserve good aesthetic and functional outcomes. The purpose of this review is to report a case of an unusually large seborrheic keratosis on the face, highlighting its clinical relevance and surgical management.

  6. Rigor mortis in an unusual position: Forensic considerations.

    Science.gov (United States)

    D'Souza, Deepak H; Harish, S; Rajesh, M; Kiran, J

    2011-07-01

    We report a case in which the dead body was found with rigor mortis in an unusual position. The dead body was lying on its back with limbs raised, defying gravity. Direction of the salivary stains on the face was also defying the gravity. We opined that the scene of occurrence of crime is unlikely to be the final place where the dead body was found. The clues were revealing a homicidal offence and an attempt to destroy the evidence. The forensic use of 'rigor mortis in an unusual position' is in furthering the investigations, and the scientific confirmation of two facts - the scene of death (occurrence) is different from the scene of disposal of dead body, and time gap between the two places.

  7. Effects of cosmic-string framework on the thermodynamical properties of anharmonic oscillator using the ordinary statistics and the q-deformed superstatistics approaches

    Energy Technology Data Exchange (ETDEWEB)

    Sobhani, Hadi; Hassanabadi, Hassan [Shahrood University of Technology, Faculty of Physics, Shahrood (Iran, Islamic Republic of); Chung, Won Sang [Gyeongsang National University, Department of Physics and Research Institute of Natural Science, College of Natural Science, Jinju (Korea, Republic of)

    2018-02-15

    In this article, we determine the thermodynamical properties of the anharmonic canonical ensemble within the cosmic-string framework. We use the ordinary statistics and the q-deformed superstatistics for this study. The q-deformed superstatistics is derived by modifying the probability density in the original superstatistics. The Schroedinger equation is rewritten in the cosmic-string framework. Next, the anharmonic oscillator is investigated in detail. The wave function and the energy spectrum of the considered system are derived using the bi-confluent Heun functions. In the next step, we first determine the thermodynamical properties for the canonical ensemble of the anharmonic oscillator in the cosmic-string framework using the ordinary statistics approach. Also, these quantities have been obtained in the q-deformed superstatistics. For vanishing deformation parameter, the ordinary results are obtained. (orig.)

  8. Statistical mechanics

    CERN Document Server

    Jana, Madhusudan

    2015-01-01

    Statistical mechanics is self sufficient, written in a lucid manner, keeping in mind the exam system of the universities. Need of study this subject and its relation to Thermodynamics is discussed in detail. Starting from Liouville theorem gradually, the Statistical Mechanics is developed thoroughly. All three types of Statistical distribution functions are derived separately with their periphery of applications and limitations. Non-interacting ideal Bose gas and Fermi gas are discussed thoroughly. Properties of Liquid He-II and the corresponding models have been depicted. White dwarfs and condensed matter physics, transport phenomenon - thermal and electrical conductivity, Hall effect, Magneto resistance, viscosity, diffusion, etc. are discussed. Basic understanding of Ising model is given to explain the phase transition. The book ends with a detailed coverage to the method of ensembles (namely Microcanonical, canonical and grand canonical) and their applications. Various numerical and conceptual problems ar...

  9. Statistical optics

    Science.gov (United States)

    Goodman, J. W.

    This book is based on the thesis that some training in the area of statistical optics should be included as a standard part of any advanced optics curriculum. Random variables are discussed, taking into account definitions of probability and random variables, distribution functions and density functions, an extension to two or more random variables, statistical averages, transformations of random variables, sums of real random variables, Gaussian random variables, complex-valued random variables, and random phasor sums. Other subjects examined are related to random processes, some first-order properties of light waves, the coherence of optical waves, some problems involving high-order coherence, effects of partial coherence on imaging systems, imaging in the presence of randomly inhomogeneous media, and fundamental limits in photoelectric detection of light. Attention is given to deterministic versus statistical phenomena and models, the Fourier transform, and the fourth-order moment of the spectrum of a detected speckle image.

  10. Pediatric sciatic neuropathies due to unusual vascular causes

    NARCIS (Netherlands)

    Srinivasan, Jayashri; Escolar, Diane; Ryan, Monique; Darras, Basil; Jones, H. Royden

    Four cases of pediatric sciatic neuropathies due to unusual vascular mechanisms are reported. Pediatric sciatic neuropathies were seen after umbilical artery catheterization, embolization of arteriovenous malformation, meningococcemia, and hypereosinophilic vasculitis. Electrophysiologic studies

  11. What is between Fermi-Dirac and Bose-Einstein Statistics?

    OpenAIRE

    Byczuk, Krzysztof; Spalek, Jozef; Joyce, Geoffrey; Sarkar, Sarben

    2004-01-01

    We overwiev the properties of a quantum gas of particles with the intermediate statistics defined by Haldane. Although this statistics has no direct connection to the symmetry of the multiparticle wave function, the statistical distribution function interpolates continuously between the Fermi-Dirac and the Bose-Einstein limits. We present an explicit solution of the transcendental equation for the didtribution function in a general case, as well as determine the thermodynamic properties in bo...

  12. Gentile statistics and restricted partitions

    Indian Academy of Sciences (India)

    The partition function of Gentile statistics also has the property that it nicely interpolates between the ... We now construct the partition function for such a system which also incorporates the property of interpolation ... As in [4], we however keep s arbitrary even though for s > 2 there are no quadratic. Hamiltonian systems.

  13. Establishing statistical models of manufacturing parameters

    International Nuclear Information System (INIS)

    Senevat, J.; Pape, J.L.; Deshayes, J.F.

    1991-01-01

    This paper reports on the effect of pilgering and cold-work parameters on contractile strain ratio and mechanical properties that were investigated using a large population of Zircaloy tubes. Statistical models were established between: contractile strain ratio and tooling parameters, mechanical properties (tensile test, creep test) and cold-work parameters, and mechanical properties and stress-relieving temperature

  14. The Relationship between Clinical Presentation and Unusual Sensory Interests in Autism Spectrum Disorders: A Preliminary Investigation

    Science.gov (United States)

    Zachor, Ditza A.; Ben-Itzchak, Esther

    2014-01-01

    Unusual responses to sensory stimuli have been described in autism spectrum disorder (ASD).The study examined the frequencies of "unusual sensory interests" and "negative sensory responses" and their relation to functioning in a large ASD population (n = 679). Having "unusual sensory interests" was reported in 70.4%…

  15. Unusual presentation of cutaneous leiomyoma

    Directory of Open Access Journals (Sweden)

    Sapnashree Bhaskar

    2014-01-01

    Full Text Available Herein, we report a case of leiomyoma cutis because of its rarity and unusual presentation. The case presented with a solitary leiomyoma lesion which was painless. However, the adjacent normal appearing area was tender. A biopsy of the lesion as well as of a portion of the adjacent normal appearing area was taken, which confirmed the diagnosis of cutaneous leiomyoma. This may suggest the dormant nature of the disease which has not yet become apparent.

  16. Unusual skeletal metastases from myxoid liposarcoma only detectable by MR imaging

    International Nuclear Information System (INIS)

    Ishii, T.; Ueda, T.; Myoui, A.; Tamai, N.; Hosono, N.; Yoshikawa, H.

    2003-01-01

    We present two cases of skeletal metastases from myxoid liposarcoma, occurring several years after treatment of the primary tumors in the lower limb. The present two case reports have unusual radiological features only detectable by MR imaging and not by plain radiographs or bone scans. From the present two cases, we found that a negative plain radiograph of the spine or a negative bone scan could not exclude skeletal metastases from myxoid liposarcoma, and MRI was a more sensitive screening procedure for their detection, especially in T1-weighted images. Unusual radiological features of skeletal metastases from myxoid liposarcoma are not well documented and only a few cases have been previously reported. Our aim is to document two more patients exhibiting the unusual radiological features of skeletal metastases from myxoid liposarcoma to improve their early detection and management. (orig.)

  17. Several unusual cases of child abuse.

    Science.gov (United States)

    Palmer, H; Weston, J T

    1976-10-01

    All childhood deaths which occurred in New Mexico during 1974 and 1975 were reviewed. Nine fatal instances of abuse were identified representing the entire spectrum of physical abuse: neglect, abuse in a single episode of injury, repetitive abuse, or sexual abuse. Several cases are summarized. These are unusual either in the distribution of pathologic findings or in the problems encountered in court presentation.

  18. Unusual signal intensity of congenital pulmonary airway malformation on fetal magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Owada, Keiho; Miyazaki, Osamu; Nosaka, Shunsuke [National Center for Child Health and Development, Department of Radiology, Tokyo (Japan); Matsuoka, Kentaro [National Center for Child Health and Development, Department of Pathology, Tokyo (Japan); Sago, Haruhiko [National Center for Child Health and Development, Department of Perinatal Medicine and Maternal Care, Tokyo (Japan)

    2015-05-01

    Congenital pulmonary airway malformation (CPAM) is classified into pathologically different types. These types are sometimes distinguishable by fetal lung MRI and are usually observed as higher-signal lesions on T2-weighted images than normal lung. We describe a case of unusual CPAM resembling neoplasms, with a lower signal than is found in normal lung. Histopathology showed a large number of mucogenic cells but found no evidence that could explain this feature on fetal MRI. An unusual low-signal mass associated with a pulmonary cyst in fetal lung on MRI may suggest an unusual type 1 CPAM. (orig.)

  19. Unusual signal intensity of congenital pulmonary airway malformation on fetal magnetic resonance imaging

    International Nuclear Information System (INIS)

    Owada, Keiho; Miyazaki, Osamu; Nosaka, Shunsuke; Matsuoka, Kentaro; Sago, Haruhiko

    2015-01-01

    Congenital pulmonary airway malformation (CPAM) is classified into pathologically different types. These types are sometimes distinguishable by fetal lung MRI and are usually observed as higher-signal lesions on T2-weighted images than normal lung. We describe a case of unusual CPAM resembling neoplasms, with a lower signal than is found in normal lung. Histopathology showed a large number of mucogenic cells but found no evidence that could explain this feature on fetal MRI. An unusual low-signal mass associated with a pulmonary cyst in fetal lung on MRI may suggest an unusual type 1 CPAM. (orig.)

  20. Statistical symmetries in physics

    International Nuclear Information System (INIS)

    Green, H.S.; Adelaide Univ., SA

    1994-01-01

    Every law of physics is invariant under some group of transformations and is therefore the expression of some type of symmetry. Symmetries are classified as geometrical, dynamical or statistical. At the most fundamental level, statistical symmetries are expressed in the field theories of the elementary particles. This paper traces some of the developments from the discovery of Bose statistics, one of the two fundamental symmetries of physics. A series of generalizations of Bose statistics is described. A supersymmetric generalization accommodates fermions as well as bosons, and further generalizations, including parastatistics, modular statistics and graded statistics, accommodate particles with properties such as 'colour'. A factorization of elements of ggl(n b ,n f ) can be used to define truncated boson operators. A general construction is given for q-deformed boson operators, and explicit constructions of the same type are given for various 'deformed' algebras. A summary is given of some of the applications and potential applications. 39 refs., 2 figs

  1. Case Report: Unusual computed tomographic features of ...

    African Journals Online (AJOL)

    A case report of a 57-year old woman who presented with signs and symptoms of intracranial mass. Computed tomographic (CT) and clinical features were unusual and suggestive of a parasaggital Meningioma. However an accurate diagnosis of a tuberculoma was made at surgery and histopathological examination.

  2. Nonlinear wave chaos: statistics of second harmonic fields.

    Science.gov (United States)

    Zhou, Min; Ott, Edward; Antonsen, Thomas M; Anlage, Steven M

    2017-10-01

    Concepts from the field of wave chaos have been shown to successfully predict the statistical properties of linear electromagnetic fields in electrically large enclosures. The Random Coupling Model (RCM) describes these properties by incorporating both universal features described by Random Matrix Theory and the system-specific features of particular system realizations. In an effort to extend this approach to the nonlinear domain, we add an active nonlinear frequency-doubling circuit to an otherwise linear wave chaotic system, and we measure the statistical properties of the resulting second harmonic fields. We develop an RCM-based model of this system as two linear chaotic cavities coupled by means of a nonlinear transfer function. The harmonic field strengths are predicted to be the product of two statistical quantities and the nonlinearity characteristics. Statistical results from measurement-based calculation, RCM-based simulation, and direct experimental measurements are compared and show good agreement over many decades of power.

  3. Statistical physics including applications to condensed matter

    CERN Document Server

    Hermann, Claudine

    2005-01-01

    Statistical Physics bridges the properties of a macroscopic system and the microscopic behavior of its constituting particles, otherwise impossible due to the giant magnitude of Avogadro's number. Numerous systems of today's key technologies -- as e.g. semiconductors or lasers -- are macroscopic quantum objects; only statistical physics allows for understanding their fundamentals. Therefore, this graduate text also focuses on particular applications such as the properties of electrons in solids with applications, and radiation thermodynamics and the greenhouse effect.

  4. Statistical Model Checking of Rich Models and Properties

    DEFF Research Database (Denmark)

    Poulsen, Danny Bøgsted

    in undecidability issues for the traditional model checking approaches. Statistical model checking has proven itself a valuable supplement to model checking and this thesis is concerned with extending this software validation technique to stochastic hybrid systems. The thesis consists of two parts: the first part...... motivates why existing model checking technology should be supplemented by new techniques. It also contains a brief introduction to probability theory and concepts covered by the six papers making up the second part. The first two papers are concerned with developing online monitoring techniques...... systems. The fifth paper shows how stochastic hybrid automata are useful for modelling biological systems and the final paper is concerned with showing how statistical model checking is efficiently distributed. In parallel with developing the theory contained in the papers, a substantial part of this work...

  5. Peroneal Arteriovenous Fistula and Pseudoaneurysm: An Unusual Presentation

    Directory of Open Access Journals (Sweden)

    Kevin C. Ching

    2014-01-01

    Full Text Available Peroneal artery arteriovenous fistulas and pseudoaneurysms are extremely rare with the majority of reported cases due to penetrating, orthopedic, or iatrogenic trauma. Failure to diagnose this unusual vascular pathology may lead to massive hemorrhage or limb threatening ischemia. We report an interesting case of a 14-year-old male who presented with acute musculoskeletal pain of his lower extremity. Initial radiographs were negative. Further imaging workup revealed a peroneal arteriovenous fistula with a large pseudoaneurysm. After initial endovascular intervention was unsuccessful, the vessels were surgically ligated in the operating room. Pathology revealed papillary endothelial hyperplasia consistent with an aneurysm and later genetic testing was consistent with Ehlers-Danlos syndrome Type IV. This case illustrates an unusual cause of acute atraumatic musculoskeletal pain and uncommon presentation of Ehlers-Danlos syndrome.

  6. An unusual case of calcineurine inhibitor pain syndrome.

    Science.gov (United States)

    Nickavar, Azar; Mehrazma, Mitra; Hallaji, Farideh

    2014-09-01

    Cyclosporine induced pain syndrome (CIPS) is a newly diagnosed complication of calcineurine inhibitors, mainly observed in solid organ and hematopoetic transplantations. The present case is a male child with steroid resistant nephrotic syndrome on low therapeutic level cyclosporine treatment. He presented with intractable and debilitating leg pain, with no reported history of previous injury or trauma. The pain was reluctant to antimicrobial and sedative treatment. MRI revealed bone marrow and soft tissue edema in the mid shaft of patient's right leg. Inspite of unusual manifestations, CIPS was suggested and cyclosporine discontinued. However, the pain did not improve and was resistant to calcium blocker. Subsequently, core decompression was performed as an unusual treatment of CIPS, revealing normal bone morphology. The pain improved rapidly and the patient was discharged a few days later.

  7. Matrix algebra theory, computations and applications in statistics

    CERN Document Server

    Gentle, James E

    2017-01-01

    This textbook for graduate and advanced undergraduate students presents the theory of matrix algebra for statistical applications, explores various types of matrices encountered in statistics, and covers numerical linear algebra. Matrix algebra is one of the most important areas of mathematics in data science and in statistical theory, and the second edition of this very popular textbook provides essential updates and comprehensive coverage on critical topics in mathematics in data science and in statistical theory. Part I offers a self-contained description of relevant aspects of the theory of matrix algebra for applications in statistics. It begins with fundamental concepts of vectors and vector spaces; covers basic algebraic properties of matrices and analytic properties of vectors and matrices in multivariate calculus; and concludes with a discussion on operations on matrices in solutions of linear systems and in eigenanalysis. Part II considers various types of matrices encountered in statistics, such as...

  8. Cutaneous sporotrichosis: Unusual clinical presentations

    Directory of Open Access Journals (Sweden)

    Mahajan Vikram

    2010-01-01

    Full Text Available Three unusual clinical forms of sporotrichosis described in this paper will be a primer for the clinicians for an early diagnosis and treatment, especially in its unusual presentations. Case 1, a 52-year-old man, developed sporotrichosis over pre-existing facial nodulo-ulcerative basal cell carcinoma of seven-year duration, due to its contamination perhaps from topical herbal pastes and lymphocutaneous sporotrichosis over right hand/forearm from facial lesion/herbal paste. Case 2, a 25-year-old woman, presented with disseminated systemic-cutaneous, osteoarticular and possibly pleural (effusion sporotrichosis. There was no laboratory evidence of tuberculosis and treatment with anti-tuberculosis drugs (ATT did not benefit. Both these cases were diagnosed by histopathology/culture of S. schenckii from tissue specimens. Case 3, a 20-year-old girl, had multiple intensely pruritic, nodular lesions over/around left knee of two-year duration. She was diagnosed clinically as a case of prurigo nodularis and histologically as cutaneous tuberculosis, albeit, other laboratory investigations and treatment with ATT did not support the diagnosis. All the three patients responded well to saturated solution of potassium iodide (SSKI therapy. A high clinical suspicion is important in early diagnosis and treatment to prevent chronicity and morbidity in these patients. SSKI is fairly safe and effective when itraconazole is not affordable/ available.

  9. Statistical aspects of nuclear structure

    International Nuclear Information System (INIS)

    Parikh, J.C.

    1977-01-01

    The statistical properties of energy levels and a statistical approach to transition strengths are discussed in relation to nuclear structure studies at high excitation energies. It is shown that the calculations can be extended to the ground state domain also. The discussion is based on the study of random matrix theory of level density and level spacings, using the Gaussian Orthogonal Ensemble (GOE) concept. The short range and long range correlations are also studied statistically. The polynomial expansion method is used to obtain excitation strengths. (A.K.)

  10. Highly Porous, Rigid-Rod Polyamide Aerogels with Superior Mechanical Properties and Unusually High Thermal Conductivity.

    Science.gov (United States)

    Williams, Jarrod C; Nguyen, Baochau N; McCorkle, Linda; Scheiman, Daniel; Griffin, Justin S; Steiner, Stephen A; Meador, Mary Ann B

    2017-01-18

    We report here the fabrication of polyamide aerogels composed of poly-p-phenylene-terephthalamide, the same backbone chemistry as DuPont's Kevlar. The all-para-substituted polymers gel without the use of cross-linker and maintain their shape during processing-an improvement over the meta-substituted cross-linked polyamide aerogels reported previously. Solutions containing calcium chloride (CaCl 2 ) and para-phenylenediamine (pPDA) in N-methylpyrrolidinone (NMP) at low temperature are reacted with terephthaloyl chloride (TPC). Polymerization proceeds over the course of 5 min resulting in gelation. Removal of the reaction solvent via solvent exchange followed by extraction with supercritical carbon dioxide provides aerogels with densities ranging from 0.1 to 0.3 g/cm 3 , depending on the concentration of calcium chloride, the formulated number of repeat units, n, and the concentration of polymer in the reaction mixture. These variables were assessed in a statistical experimental study to understand their effects on the properties of the aerogels. Aerogels made using at least 30 wt % CaCl 2 had the best strength when compared to aerogels of similar density. Furthermore, aerogels made using 30 wt % CaCl 2 exhibited the lowest shrinkage when aged at elevated temperatures. Notably, whereas most aerogel materials are highly insulating (thermal conductivities of 10-30 mW/m K), the polyamide aerogels produced here exhibit remarkably high thermal conductivities (50-80 mW/(m K)) at the same densities as other inorganic and polymer aerogels. These high thermal conductivities are attributed to efficient phonon transport by the rigid-rod polymer backbone. In conjunction with their low cost, ease of fabrication with respect to other polymer aerogels, low densities, and high mass-normalized strength and stiffness properties, these aerogels are uniquely valuable for applications such as lightweighting in consumer electronics, automobiles, and aerospace where weight reduction is

  11. Unusual motions of a vibrating string

    Science.gov (United States)

    Hanson, Roger J.

    2003-10-01

    The actual motions of a sinusoidally driven vibrating string can be very complex due to nonlinear effects resulting from varying tension and longitudinal motion not included in simple linear theory. Commonly observed effects are: generation of motion perpendicular to the driving force, sudden jumps in amplitude, hysteresis, and generation of higher harmonics. In addition, these effects are profoundly influenced by wire asymmetries which in a brass harpsichord wire can cause a small splitting of each natural frequency of free vibration into two closely spaced frequencies (relative separation ~0.2% to 2%), each associated with transverse motion along two orthogonal characteristic wire axes. Some unusual resulting patterns of complex motions of a point on the wire are exhibited on videotape. Examples include: sudden changes of harmonic content, generation of subharmonics, and motion which appears nearly chaotic but which has a pattern period of over 10 s. Another unusual phenomenon due to entirely different causes can occur when a violin string is bowed with a higher than normal force resulting in sounds ranging from about a musical third to a twelfth lower than the sound produced when the string is plucked.

  12. Statistical physics

    CERN Document Server

    Guénault, Tony

    2007-01-01

    In this revised and enlarged second edition of an established text Tony Guénault provides a clear and refreshingly readable introduction to statistical physics, an essential component of any first degree in physics. The treatment itself is self-contained and concentrates on an understanding of the physical ideas, without requiring a high level of mathematical sophistication. A straightforward quantum approach to statistical averaging is adopted from the outset (easier, the author believes, than the classical approach). The initial part of the book is geared towards explaining the equilibrium properties of a simple isolated assembly of particles. Thus, several important topics, for example an ideal spin-½ solid, can be discussed at an early stage. The treatment of gases gives full coverage to Maxwell-Boltzmann, Fermi-Dirac and Bose-Einstein statistics. Towards the end of the book the student is introduced to a wider viewpoint and new chapters are included on chemical thermodynamics, interactions in, for exam...

  13. Unusual complication and successful high-dose chemotherapy ...

    African Journals Online (AJOL)

    ... treated with high-dose chemotherapy in our institution, complicated by unusual bilateral renal vein tumour thrombi and tumour lysis syndrome. We believe this unique case highlights the need for early recognition of current and potential complications on staging computed tomography imaging, as well as successful use of ...

  14. Unusual headaches in the elderly.

    Science.gov (United States)

    Bamford, Cynthia C; Mays, MaryAnn; Tepper, Stewart J

    2011-08-01

    Prevalence of headache lowers with age, and headaches of elderly adults tend to be different than those of the younger population. Secondary headaches, such as headaches associated with vascular disease, head trauma, and neoplasm, are more common. Also, certain headache types tend to be geriatric disorders, such as primary cough headache, hypnic headache, typical aura without headache, exploding head syndrome, and giant cell arteritis. This review provides an overview of some of the major and unusual geriatric headaches, both primary and secondary.

  15. Generalized statistical mechanics approaches to earthquakes and tectonics

    Science.gov (United States)

    Papadakis, Giorgos; Michas, Georgios

    2016-01-01

    Despite the extreme complexity that characterizes the mechanism of the earthquake generation process, simple empirical scaling relations apply to the collective properties of earthquakes and faults in a variety of tectonic environments and scales. The physical characterization of those properties and the scaling relations that describe them attract a wide scientific interest and are incorporated in the probabilistic forecasting of seismicity in local, regional and planetary scales. Considerable progress has been made in the analysis of the statistical mechanics of earthquakes, which, based on the principle of entropy, can provide a physical rationale to the macroscopic properties frequently observed. The scale-invariant properties, the (multi) fractal structures and the long-range interactions that have been found to characterize fault and earthquake populations have recently led to the consideration of non-extensive statistical mechanics (NESM) as a consistent statistical mechanics framework for the description of seismicity. The consistency between NESM and observations has been demonstrated in a series of publications on seismicity, faulting, rock physics and other fields of geosciences. The aim of this review is to present in a concise manner the fundamental macroscopic properties of earthquakes and faulting and how these can be derived by using the notions of statistical mechanics and NESM, providing further insights into earthquake physics and fault growth processes. PMID:28119548

  16. The statistical properties of recreational catch rate data for some fish stocks off the northeast U.S. coast

    OpenAIRE

    Terceiro, Mark

    2003-01-01

    Recreational fisheries in the waters off the northeast U.S. target a variety of pelagic and demersal fish species, and catch and effort data sampled from recreational fisheries are a critical component of the information used in resource evaluation and management. Standardized indices of stock abundance developed from recreational fishery catch rates are routinely used in stock assessments. The statistical properties of both simulated and empirical recreational fishery catch-rate data such...

  17. Experience from unusual occurrences in HWP (Tuticorin) (Paper No. 4.8)

    International Nuclear Information System (INIS)

    Kanthiah, W.S.A.; Vaidyan, P.A.O.; Bhowmick, S.C.

    1992-01-01

    During the operation of heavy water plants a number of unusual incidents do occur which are hurdles to the smooth operation of the system. An attempt has been made to give a detailed study of a few cases of unusual occurrences such as rupture of ammonia cracker tubes, water entry in cable junction box through nitrogen line, potassium amide splash on maintenance personnel, booster compressor trip explosion in effluent system, etc. in Heavy Water Plant, Tuticorin. (author). 5 figs

  18. Superfluid 3He at very low temperatures: a very unusual excitation gas

    International Nuclear Information System (INIS)

    Pickett, G.R.; Enrico, M.P.; Fisher, S.N.; Guenault, A.M.; Torizuka, K.

    1994-01-01

    The excitation gas in superfluid 3 He at low temperatures shows a number of remarkable dynamical properties arising from the unusual dispersion curve. The existence of an energy gap leads to many of the observed properties varying rapidly with temperature, since the excitation density is dominated by the gap Boltzmann factor exp(-Δ/kT). But also, the fact that the minimum energy lies at finite momentum gives rise to Andreev scattering processes, in which the velocity of the excitation is reversed but the momentum left virtually unchanged. Since the dispersion curve looks different to a moving observer, there is the possibility of the free production of quasiparticle-quasihole pairs at a Landau critical velocity. At low temperatures the mean free path becomes much larger than any experimental size. Using vibrating wire resonators as universal probes, we can monitor the temperature, measure the Kapitz resistance, examine the nonlinear regime beyond the two-fluid model, observe the Landau velocity, create and detect thermal beams of excitation with black-body radiators, observe Andreev reflection directly and probe A-phase textures (in which the gas is one-dimensional). Future possibilities are discussed. (orig.)

  19. Statistical properties and fractals of nucleotide clusters in DNA sequences

    International Nuclear Information System (INIS)

    Sun Tingting; Zhang Linxi; Chen Jin; Jiang Zhouting

    2004-01-01

    Statistical properties of nucleotide clusters in DNA sequences and their fractals are investigated in this paper. The average size of nucleotide clusters in non-coding sequence is larger than that in coding sequence. We investigate the cluster-size distribution P(S) for human chromosomes 21 and 22, and the results are different from previous works. The cluster-size distribution P(S 1 +S 2 ) with the total size of sequential Pu-cluster and Py-cluster S 1 +S 2 is studied. We observe that P(S 1 +S 2 ) follows an exponential decay both in coding and non-coding sequences. However, we get different results for human chromosomes 21 and 22. The probability distribution P(S 1 ,S 2 ) of nucleotide clusters with the size of sequential Pu-cluster and Py-cluster S 1 and S 2 respectively, is also examined. In the meantime, some of the linear correlations are obtained in the double logarithmic plots of the fluctuation F(l) versus nucleotide cluster distance l along the DNA chain. The power spectrums of nucleotide clusters are also discussed, and it is concluded that the curves are flat and hardly changed and the 1/3 frequency is neither observed in coding sequence nor in non-coding sequence. These investigations can provide some insights into the nucleotide clusters of DNA sequences

  20. The Statistical Properties of Galaxies Containing Ultraluminous X-Ray Objects

    Science.gov (United States)

    Ptak, A.; Colbert, E.

    2004-05-01

    We present a statistical analysis of the properties of galaxies containing ultraluminous X-ray objects (ULXs). Our primary goal is to establish the fraction of galaxies containing a ULX as a function of ULX luminosity. Our sample is based on ROSAT HRI observations of galaxies. We find that ~12% of galaxies contain at least one ULX with LX>1039 ergs s-1, and ~1% of galaxies contain at least one ULX with LX>1040 ergs s-1. These ULX frequencies are lower limits, since ROSAT HRI observations would miss absorbed ULXs (i.e., with NH>~1021cm-2) and those within ~10" of the nucleus (due to the positional error circle of the ROSAT HRI). The Hubble type distribution of galaxies with a ULX differs significantly from the distribution of types for nearby Third Reference Catalog galaxies but does not differ significantly from the galaxy type distribution of galaxies observed by the HRI in general. We find no increase in the mean far-infrared (FIR) luminosity or FIR/K-band luminosity ratio for galaxies with a ULX relative to galaxies observed by the HRI in general; however, this result is also most likely biased by the soft bandpass of the HRI and the relatively low number of high star formation rate galaxies observed by the HRI with enough sensitivity to detect a ULX.

  1. Probable Unusual Transmission of Zika Virus

    Centers for Disease Control (CDC) Podcasts

    2011-05-23

    This podcast discusses a study about the probable unusual transmission of Zika Virus Infection from a scientist to his wife, published in the May 2011 issue of Emerging Infectious Diseases. Dr. Brian Foy, Associate Professor at Colorado State University, shares details of this event.  Created: 5/23/2011 by National Center for Emerging Zoonotic and Infectious Diseases (NCEZID).   Date Released: 5/25/2011.

  2. Emphysematous cystitis: An unusual lower urinary tract infection ...

    African Journals Online (AJOL)

    Emphysematous cystitis: An unusual lower urinary tract infection. MA Lakmichi, M Boukhar, F Barjani, O Saghir, T Hanich, B Wakrim, M Gabsi, A Elhauos, N Charif Idrissi Genouni, N Ousehal, Z Dahami, SM Moudouni, I Sarf ...

  3. Statistical Estimators Using Jointly Administrative and Survey Data to Produce French Structural Business Statistics

    Directory of Open Access Journals (Sweden)

    Brion Philippe

    2015-12-01

    Full Text Available Using as much administrative data as possible is a general trend among most national statistical institutes. Different kinds of administrative sources, from tax authorities or other administrative bodies, are very helpful material in the production of business statistics. However, these sources often have to be completed by information collected through statistical surveys. This article describes the way Insee has implemented such a strategy in order to produce French structural business statistics. The originality of the French procedure is that administrative and survey variables are used jointly for the same enterprises, unlike the majority of multisource systems, in which the two kinds of sources generally complement each other for different categories of units. The idea is to use, as much as possible, the richness of the administrative sources combined with the timeliness of a survey, even if the latter is conducted only on a sample of enterprises. One main issue is the classification of enterprises within the NACE nomenclature, which is a cornerstone variable in producing the breakdown of the results by industry. At a given date, two values of the corresponding code may coexist: the value of the register, not necessarily up to date, and the value resulting from the data collected via the survey, but only from a sample of enterprises. Using all this information together requires the implementation of specific statistical estimators combining some properties of the difference estimators with calibration techniques. This article presents these estimators, as well as their statistical properties, and compares them with those of other methods.

  4. An unusual case of the Capgras syndrome.

    Science.gov (United States)

    Fialkov, M J; Robins, A H

    1978-04-01

    A variant of the Capgras syndrome is described in a 43-year-old woman who had vitiligo and multinodular goitre. The unusual feature of the case was that the patient not only misidentified members of her own family but also claimed that she herself had been replaced by a double.

  5. Unusual Market Activity Announcements: A Study of Price Manipulation on the Indonesian Stock Exchange

    Directory of Open Access Journals (Sweden)

    Mamduh M. Hanafi

    2010-05-01

    Full Text Available We investigate stocks involved in the Unusual Market Activity (UMA Announcements. The Indonesian Stock Exchange occasionally issues UMA announcements when it suspects that there are unusual price increases (positive UMAs or price decreases (negative UMAs, as well as unusual increases in trading volumes. We believe that UMA announcements signal a high probability that stocks are being manipulated. We find no differences in fundamentals and trading variables between stocks in the UMA announcements and those not in the UMA announcements. Any stock is vulnerable to market manipulation. Stocks in the UMA announcements do not exhibit reversal patterns, suggesting that price effect is permanent. UMAs seem to convey relevant information, which is most likely in the form of insider type of information. Keywords: emerging market; price manipulation; unusual market activity announcement.

  6. Quantum statistics and liquid helium 3 - helum 4 mixtures

    International Nuclear Information System (INIS)

    Cohen, E.G.D.

    1979-01-01

    The behaviour of liquid helium 3-helium 4 mixtures is considered from the point of view of manifestation of quantum statistics effects in macrophysics. The Boze=Einstein statistics is shown to be of great importance for understanding superfluid helium-4 properties whereas the Fermi-Dirac statistics is of importance for understanding helium-3 properties. Without taking into consideration the interaction between the helium atoms it is impossible to understand the basic properties of liquid helium 33 - helium 4 mixtures at constant pressure. Proposed is a simple model of the liquid helium 3-helium 4 mixture, namely the binary mixture consisting of solid spheres of two types subjecting to the Fermi-Dirac and Bose-Einstein statistics relatively. This model predicts correctly the most surprising peculiarities of phase diagrams of concentration dependence on temperature for helium solutions. In particular, the helium 4 Bose-Einstein statistics is responsible for the phase lamination of helium solutions at low temperatures. It starts in the peculiar critical point. The helium 4 Fermi-Dirac statistics results in incomplete phase lamination close to the absolute zero temperatures, that permits operation of a powerful cooling facility, namely refrigerating machine on helium solution

  7. Evolution of IPv6 Internet topology with unusual sudden changes

    International Nuclear Information System (INIS)

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

    2013-01-01

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

  8. Evolution of IPv6 Internet topology with unusual sudden changes

    Science.gov (United States)

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

    2013-07-01

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

  9. Statistical studies of powerful extragalactic radio sources

    Energy Technology Data Exchange (ETDEWEB)

    Macklin, J T

    1981-01-01

    This dissertation is mainly about the use of efficient statistical tests to study the properties of powerful extragalactic radio sources. Most of the analysis is based on subsets of a sample of 166 bright (3CR) sources selected at 178 MHz. The first chapter is introductory and it is followed by three on the misalignment and symmetry of double radio sources. The properties of nuclear components in extragalactic sources are discussed in the next chapter, using statistical tests which make efficient use of upper limits, often the only available information on the flux density from the nuclear component. Multifrequency observations of four 3CR sources are presented in the next chapter. The penultimate chapter is about the analysis of correlations involving more than two variables. The Spearman partial rank correlation coefficient is shown to be the most powerful test available which is based on non-parametric statistics. It is therefore used to study the dependences of the properties of sources on their size at constant redshift, and the results are interpreted in terms of source evolution. Correlations of source properties with luminosity and redshift are then examined.

  10. Dysphagia as an unusual complication of pleural mesothelioma

    International Nuclear Information System (INIS)

    Khan, S.; But, N.; Bajwa, F.

    2008-01-01

    Dysphagia is an unusual presentation of pleural mesothelioma and carries a grim prognosis. A case of an elderly patient is presented herein, in whom the diagnosis was confirmed histologically, and the patient was still surviving 6 months after palliation. (author)

  11. Cognitive control and unusual decisions about beauty: An fMRI study

    Directory of Open Access Journals (Sweden)

    Albert eFlexas

    2014-07-01

    Full Text Available Studies of visual aesthetic preference have shown that people without art training generally prefer representational paintings to abstract paintings. This, however, is not always the case: preferences can sometimes go against this usual tendency. We aimed to explore this issue, investigating the relationship between ‘unusual responses’ and reaction time in an aesthetic appreciation task. Results of a behavioural experiment confirmed the trend for laypeople to consider as beautiful mostly representational stimuli and as not beautiful mostly abstract ones (‘usual response’. Furthermore, when participants gave unusual responses, they needed longer time, especially when considering abstract stimuli as beautiful. We interpreted this longer time as greater involvement of the cognitive mastering and evaluation stages during the unusual responses. Results of an fMRI experiment indicated that the anterior cingulate, orbitofrontal cortex and insula were the main structures involved in this effect. We discuss the possible role of these areas in an aesthetic appreciation task.

  12. Unusual occurrences during LMFR operation. Proceedings of a technical committee meeting

    International Nuclear Information System (INIS)

    2000-10-01

    Design of liquid metal cooled fast reactors (LMFRs) is still in evolution, and only a small number of LMFRs are in operation around the world. Specialists operating these LMFRs have gained valuable experience from incidents, failures, and other events that took place in the reactors. These unusual occurrences, lessons learned and measures undertaken to prevent recurrences are often either not reported in the literature, or reported only briefly and without sufficient detail. Hence there is a need for specialists designing and operating LMFRs to share their knowledge on unusual occurrences. Considerable experimental and theoretical knowledge in this field were collected by several Member states over the past decades. The needs in generalisation, review and documentation of fundamental knowledge in liquid metal cooled reactor technology were a major consideration in the recommendation by the International Working group on fast reactors for the IAEA to convene this Technical Committee meeting on the subject of unusual occurrences during LMFR operation and the consequences for reactor systems

  13. Statistical methods in nuclear theory

    International Nuclear Information System (INIS)

    Shubin, Yu.N.

    1974-01-01

    The paper outlines statistical methods which are widely used for describing properties of excited states of nuclei and nuclear reactions. It discusses physical assumptions lying at the basis of known distributions between levels (Wigner, Poisson distributions) and of widths of highly excited states (Porter-Thomas distribution, as well as assumptions used in the statistical theory of nuclear reactions and in the fluctuation analysis. The author considers the random matrix method, which consists in replacing the matrix elements of a residual interaction by random variables with a simple statistical distribution. Experimental data are compared with results of calculations using the statistical model. The superfluid nucleus model is considered with regard to superconducting-type pair correlations

  14. Emergence of quantum mechanics from classical statistics

    International Nuclear Information System (INIS)

    Wetterich, C

    2009-01-01

    The conceptual setting of quantum mechanics is subject to an ongoing debate from its beginnings until now. The consequences of the apparent differences between quantum statistics and classical statistics range from the philosophical interpretations to practical issues as quantum computing. In this note we demonstrate how quantum mechanics can emerge from classical statistical systems. We discuss conditions and circumstances for this to happen. Quantum systems describe isolated subsystems of classical statistical systems with infinitely many states. While infinitely many classical observables 'measure' properties of the subsystem and its environment, the state of the subsystem can be characterized by the expectation values of only a few probabilistic observables. They define a density matrix, and all the usual laws of quantum mechanics follow. No concepts beyond classical statistics are needed for quantum physics - the differences are only apparent and result from the particularities of those classical statistical systems which admit a quantum mechanical description. In particular, we show how the non-commuting properties of quantum operators are associated to the use of conditional probabilities within the classical system, and how a unitary time evolution reflects the isolation of the subsystem.

  15. Unusual strain in homoepitaxial CdTe(001) layers grown by molecular beam epitaxy

    Energy Technology Data Exchange (ETDEWEB)

    Heinke, H.; Waag, A.; Moeller, M.O.; Regnet, M.M.; Landwehr, G. [Physikalisches Institut, Univ. Wuerzburg (Germany)

    1994-01-01

    For homoepitaxial CdTe(001) films grown by molecular beam epitaxy onto CdTe(001) substrates, a difference between the lattice constants of the substrate and the layer was systematically observed using high resolution X-ray diffraction. Reciprocal space maps point out an unusual strain state of such layers which is indicated by the position of their reciprocal lattice points. They lie in a section of reciprocal space which is usually forbidden by elasticity theory. The strain is laterally anisotropic leading to a monoclinic symmetry of the thin films. The lateral strain is depth dependent. Possible reasons for the formation of the unusual strain are discussed, and a correlation of the unusual strain with the growth conditions is attempted

  16. Statistical properties of intensity of partially polarised semiconductor laser light backscattered by a single-mode optical fibre

    International Nuclear Information System (INIS)

    Alekseev, A E; Potapov, V T; Gorshkov, B G

    2015-01-01

    We report the results of studying statistical properties of the intensity of partially polarised coherent light backscattered by a single mode optical fibre. An expression is derived for the deviation of the backscattered light intensity depending on the scattering region length, the degree of the light source coherence and the degree of scattered light polarisation. It is shown that the backscattered light in a fibre scattered-light interferometer is partially polarised with the polarisation degree P = 1/3 in the case of external perturbations of the interferometer fibre. (scattering of light)

  17. Hidden Statistics of Schroedinger Equation

    Science.gov (United States)

    Zak, Michail

    2011-01-01

    Work was carried out in determination of the mathematical origin of randomness in quantum mechanics and creating a hidden statistics of Schr dinger equation; i.e., to expose the transitional stochastic process as a "bridge" to the quantum world. The governing equations of hidden statistics would preserve such properties of quantum physics as superposition, entanglement, and direct-product decomposability while allowing one to measure its state variables using classical methods.

  18. 'Unusual' MRI appearance of sphenoid sinus mucocele

    International Nuclear Information System (INIS)

    Ruelle, A.; Pisani, R.; Andrioli, G.

    1991-01-01

    The authors report a case of sphenoid sinus mucocele which exhibited unusual MRI features. However a review of the literature shows that these lesions may present with different MRI appearances probably related to the variability of the cyst content. Further series are needed for a better definition of the MRI behaviour of the lesions. (orig.)

  19. Statistical theory of heat

    CERN Document Server

    Scheck, Florian

    2016-01-01

    Scheck’s textbook starts with a concise introduction to classical thermodynamics, including geometrical aspects. Then a short introduction to probabilities and statistics lays the basis for the statistical interpretation of thermodynamics. Phase transitions, discrete models and the stability of matter are explained in great detail. Thermodynamics has a special role in theoretical physics. Due to the general approach of thermodynamics the field has a bridging function between several areas like the theory of condensed matter, elementary particle physics, astrophysics and cosmology. The classical thermodynamics describes predominantly averaged properties of matter, reaching from few particle systems and state of matter to stellar objects. Statistical Thermodynamics covers the same fields, but explores them in greater depth and unifies classical statistical mechanics with quantum theory of multiple particle systems. The content is presented as two tracks: the fast track for master students, providing the essen...

  20. Unusual osteopathy in a newborn

    Energy Technology Data Exchange (ETDEWEB)

    Jequier, S.; Nogrady, M.B.; Wesenberg, R.L.

    1983-06-01

    A newborn baby presented with hyaline membrane disease, interstitial pneumonia, jaundice, hepatosplenomegaly, and unusual bone manifestations with lytic and sclerotic bone lesions and virtually absent periosteal reaction. He subsequently developed intracranial calcifications and mental retardation. The pneumonia and hepatosplenomegaly resolved. At the time of the delivery, a sibling was suffering from a severe undetermined viral infection. The clinical evolution of the disease and the radiologic findings led us to believe that this patient has a prenatal viral infection. The laboratory tests and the histologic picture of the bone biopsy supported the diagnosis.

  1. Unusual osteopathy in a newborn

    International Nuclear Information System (INIS)

    Jequier, S.; Nogrady, M.B.; Wesenberg, R.L.

    1983-01-01

    A newborn baby presented with hyaline membrane disease, interstitial pneumonia, jaundice, hepatosplenomegaly, and unusual bone manifestations with lytic and sclerotic bone lesions and virtually absent periosteal reaction. He subsequently developed intracranial calcifications and mental retardation. The pneumonia and hepatosplenomegaly resolved. At the time of the delivery, a sibling was suffering from a severe undetermined viral infection. The clinical evolution of the disease and the radiologic findings led us to believe that this patient has a prenatal viral infection. The laboratory tests and the histologic picture of the bone biopsy supported the diagnosis. (orig.)

  2. Unusual CT image of a cerebral hydatid cyst

    International Nuclear Information System (INIS)

    Gonzalez-Ruiz, C.A.; Isla, A.; Blazquez, M.G.; Perez-Higueras, A.

    1990-01-01

    We report an unusual case of cerebral hydatid cyst which was found with CT. Unenhanced CT showed a hyperdense, not calcified, ring surrounding the cyst cavity. This has never been reported before. We propose a possible explanation for such abnormal behaviour. (orig.)

  3. Functional summary statistics for the Johnson-Mehl model

    DEFF Research Database (Denmark)

    Møller, Jesper; Ghorbani, Mohammad

    The Johnson-Mehl germination-growth model is a spatio-temporal point process model which among other things have been used for the description of neurotransmitters datasets. However, for such datasets parametric Johnson-Mehl models fitted by maximum likelihood have yet not been evaluated by means...... of functional summary statistics. This paper therefore invents four functional summary statistics adapted to the Johnson-Mehl model, with two of them based on the second-order properties and the other two on the nuclei-boundary distances for the associated Johnson-Mehl tessellation. The functional summary...... statistics theoretical properties are investigated, non-parametric estimators are suggested, and their usefulness for model checking is examined in a simulation study. The functional summary statistics are also used for checking fitted parametric Johnson-Mehl models for a neurotransmitters dataset....

  4. Myopericytoma proliferating in an unusual anastomosing multinodular fashion.

    Science.gov (United States)

    Inoue, Takuya; Misago, Noriyuki; Asami, Akihiko; Tokunaga, Osamu; Narisawa, Yutaka

    2016-05-01

    We herein describe a case of myopericytoma that proliferated in an unusual fashion. Myopericytoma is described as a group of rare, benign, dermal or subcutaneous tumors that are characterized histologically by a striking, concentric, perivascular proliferation of spindle cells and showing apparent differentiation towards perivascular myoid cells. Myopericytoma forms a morphological continuum with myofibroma/myofibromatosis, glomus tumor and angioleiomyoma. The patient was a 64-year-old woman who demonstrated a recurrent ulcer on an atrophic plaque on her left shin. A histopathological examination of the plaque demonstrated that tumor cells proliferated in an anastomosing multinodular fashion along the vessels in the dermis and subcutaneous tissue. In those nodules, there were numerous, small, concentric proliferations of myoid-appearing spindle cells around small vascular lumina. The present case is an unusual example of myopericytoma, manifesting in a characteristic anastomosing, multinodular, infiltrating fashion. © 2015 Japanese Dermatological Association.

  5. Statistical mapping of the effect of knee extension on thigh muscle viscoelastic properties using magnetic resonance elastography

    International Nuclear Information System (INIS)

    Barnhill, Eric; Kennedy, Paul; Van Beek, Edwin J R; Roberts, Neil; Hammer, Steven; Brown, Colin

    2013-01-01

    Skeletal muscle viscoelastic properties reflect muscle microstructure and neuromuscular activation. Elastographic methods, including magnetic resonance elastography, have been used to characterize muscle viscoelastic properties in terms of region of interest (ROI) measurements. The present study extended this approach to create thresholded pixel-by-pixel maps of viscoelastic properties of skeletal muscle during rest and knee extension in eleven subjects. ROI measurements were taken for individual quadricep muscles and the quadriceps region as a whole, and the viscoelastic parameter map pixels were statistically tested at positive false discovery rate q ⩽ 0.25. ROI measurements showed significant (p ⩽ 0.05) increase in storage modulus (G′) and loss modulus (G″), with G″ increasing more than G′, in agreement with previous findings. The q-value maps further identified the vastus intermedius as the primary driver of this change, with greater G″/G′ increase than surrounding regions. Additionally, a cluster of significant decrease in G″/G′ was found in the region of vastus lateralis below the fulcrum point of the lift. Viscoelastic parameter mapping of contracted muscle allows new insight into the relationship between physiology, neuromuscular activation, and human performance. (paper)

  6. Structural phase transition and elastic properties of samarium monopnictides

    International Nuclear Information System (INIS)

    Pagare, Gitanjali; Chouhan, Sunil Singh; Soni, Pooja; Sanyal, Sankar P.

    2011-01-01

    In recent years the monopnictides and monochalcogenides of the rare-earth elements with rocksalt structure (B 1 ) have aroused intensive interest due to the presence of strongly correlated f electrons in them. Under pressure, the nature of f-electrons of these compounds can be changed from localized to itinerant leading to significant changes in physical and chemical properties. These unusual structural, electronic, and high-pressure properties make them candidates for advanced industrial applications. For these applications they provide unique physical properties which cannot be achieved with other materials

  7. Searches with long-lived or unusual signatures

    CERN Document Server

    Haug, S; The ATLAS collaboration

    2013-01-01

    We present recent ATLAS and CMS results from searches with long-lived and unusual signatures. They are based on analysis of LHC proton-proton collisions at center of mass energies at 7 and 8 TeV. Long-lived and heavy particles may cause peculiar signatures in the detectors, but are in several Standard Model extensions well motivated.

  8. Perspectives and challenges in statistical physics and complex systems for the next decade

    CERN Document Server

    Raposo, Ernesto P; Gomes Eleutério da Luz, Marcos

    2014-01-01

    Statistical Physics (SP) has followed an unusual evolutionary path in science. Originally aiming to provide a fundamental basis for another important branch of Physics, namely Thermodynamics, SP gradually became an independent field of research in its own right. But despite more than a century of steady progress, there are still plenty of challenges and open questions in the SP realm. In fact, the area is still rapidly evolving, in contrast to other branches of science, which already have well defined scopes and borderlines of applicability. This difference is due to the steadily expanding num

  9. Statistical aspects of determinantal point processes

    DEFF Research Database (Denmark)

    Lavancier, Frédéric; Møller, Jesper; Rubak, Ege Holger

    The statistical aspects of determinantal point processes (DPPs) seem largely unexplored. We review the appealing properties of DDPs, demonstrate that they are useful models for repulsiveness, detail a simulation procedure, and provide freely available software for simulation and statistical...... inference. We pay special attention to stationary DPPs, where we give a simple condition ensuring their existence, construct parametric models, describe how they can be well approximated so that the likelihood can be evaluated and realizations can be simulated, and discuss how statistical inference...

  10. Beyond quantum microcanonical statistics

    International Nuclear Information System (INIS)

    Fresch, Barbara; Moro, Giorgio J.

    2011-01-01

    Descriptions of molecular systems usually refer to two distinct theoretical frameworks. On the one hand the quantum pure state, i.e., the wavefunction, of an isolated system is determined to calculate molecular properties and their time evolution according to the unitary Schroedinger equation. On the other hand a mixed state, i.e., a statistical density matrix, is the standard formalism to account for thermal equilibrium, as postulated in the microcanonical quantum statistics. In the present paper an alternative treatment relying on a statistical analysis of the possible wavefunctions of an isolated system is presented. In analogy with the classical ergodic theory, the time evolution of the wavefunction determines the probability distribution in the phase space pertaining to an isolated system. However, this alone cannot account for a well defined thermodynamical description of the system in the macroscopic limit, unless a suitable probability distribution for the quantum constants of motion is introduced. We present a workable formalism assuring the emergence of typical values of thermodynamic functions, such as the internal energy and the entropy, in the large size limit of the system. This allows the identification of macroscopic properties independently of the specific realization of the quantum state. A description of material systems in agreement with equilibrium thermodynamics is then derived without constraints on the physical constituents and interactions of the system. Furthermore, the canonical statistics is recovered in all generality for the reduced density matrix of a subsystem.

  11. An Unusual Cause of Rectal Stenosis

    Directory of Open Access Journals (Sweden)

    Maja Gruber

    2016-08-01

    Full Text Available Solitary rectal ulcer syndrome (SRUS is a benign disease that is often misdiagnosed. It is characterized by a combination of symptoms, endoscopic findings and histology. Patients present with constipation, rectal bleeding, mucous discharge, pain and a sensation of incomplete defecation. There are many different manifestations of this disease, with or without rectal prolapse. We report an unusual presentation of SRUS as a circular stenosis in a middle-aged male.

  12. Unusual presentation of extrapulmonary tuberculosis: a case report ...

    African Journals Online (AJOL)

    This case study highlights an unusual manifestation of extrapulmonary tuberculosis (TB) in a person living with HIV, namely mammary TB. Clinicians practising in settings where HIV and TB are endemic need to be aware of the clinical presentation, diagnosis and management of mammary TB.

  13. Response of the Pre-oriented Goal-directed Attention to Usual and Unusual Distractors: A Preliminary Study

    Directory of Open Access Journals (Sweden)

    Golnaz Baghdadi

    2017-03-01

    Full Text Available Introduction: In this study, we investigated the distraction power of the unusual and usual images on the attention of 20 healthy primary school children. Methods: Our study was different from previous ones in that the participants were asked to fix the initial position of their attention on a pre-defined location after being presented with unusual images as distractors. The goals were presented in locations, which were far from the attraction basin of distractors. Our expectation was that the pre-orienting of the attention to the position of targets can reduce the attractive effect of unusual images compared to the usual ones. The percentage of correct responses and the reaction time have been measured as behavioral indicators of attention performance. Results: Results showed that using the goal-directed attention, subjects ignored both kinds of distractors nearly the same way. Conclusion: With regard to previous reports about the more attraction towards the unusual images, it is suggested that the dynamics of the visual attention system be sensitive to the initial condition. That is, changing the initial position of the attention can lead to the decrement of the unusual images’ effects. However, several other possibilities such as a probable delay in processing unusual features could explain this observation, too. 

  14. Statistical inference based on divergence measures

    CERN Document Server

    Pardo, Leandro

    2005-01-01

    The idea of using functionals of Information Theory, such as entropies or divergences, in statistical inference is not new. However, in spite of the fact that divergence statistics have become a very good alternative to the classical likelihood ratio test and the Pearson-type statistic in discrete models, many statisticians remain unaware of this powerful approach.Statistical Inference Based on Divergence Measures explores classical problems of statistical inference, such as estimation and hypothesis testing, on the basis of measures of entropy and divergence. The first two chapters form an overview, from a statistical perspective, of the most important measures of entropy and divergence and study their properties. The author then examines the statistical analysis of discrete multivariate data with emphasis is on problems in contingency tables and loglinear models using phi-divergence test statistics as well as minimum phi-divergence estimators. The final chapter looks at testing in general populations, prese...

  15. Statistical properties of the seasonal fractionally integrated ...

    African Journals Online (AJOL)

    We investigate the properties of this new model providing stationary conditions, some explicit form of the autocovariance function and the spectral density. We also establish the asymptotic behaviour of the spectral density function near the seasonal frequencies. Keywords: Seasonality; Spatial short memory; Seasonal long ...

  16. Statistical alignment: computational properties, homology testing and goodness-of-fit

    DEFF Research Database (Denmark)

    Hein, J; Wiuf, Carsten; Møller, Martin

    2000-01-01

    The model of insertions and deletions in biological sequences, first formulated by Thorne, Kishino, and Felsenstein in 1991 (the TKF91 model), provides a basis for performing alignment within a statistical framework. Here we investigate this model.Firstly, we show how to accelerate the statistical...... alignment algorithms several orders of magnitude. The main innovations are to confine likelihood calculations to a band close to the similarity based alignment, to get good initial guesses of the evolutionary parameters and to apply an efficient numerical optimisation algorithm for finding the maximum...... analysis.Secondly, we propose a new homology test based on this model, where homology means that an ancestor to a sequence pair can be found finitely far back in time. This test has statistical advantages relative to the traditional shuffle test for proteins.Finally, we describe a goodness-of-fit test...

  17. Free Software Development. 1. Fitting Statistical Regressions

    Directory of Open Access Journals (Sweden)

    Lorentz JÄNTSCHI

    2002-12-01

    Full Text Available The present paper is focused on modeling of statistical data processing with applications in field of material science and engineering. A new method of data processing is presented and applied on a set of 10 Ni–Mn–Ga ferromagnetic ordered shape memory alloys that are known to exhibit phonon softening and soft mode condensation into a premartensitic phase prior to the martensitic transformation itself. The method allows to identify the correlations between data sets and to exploit them later in statistical study of alloys. An algorithm for computing data was implemented in preprocessed hypertext language (PHP, a hypertext markup language interface for them was also realized and put onto comp.east.utcluj.ro educational web server, and it is accessible via http protocol at the address http://vl.academicdirect.ro/applied_statistics/linear_regression/multiple/v1.5/. The program running for the set of alloys allow to identify groups of alloys properties and give qualitative measure of correlations between properties. Surfaces of property dependencies are also fitted.

  18. Statistical properties of online avatar numbers in a massive multiplayer online role-playing game

    Science.gov (United States)

    Jiang, Zhi-Qiang; Ren, Fei; Gu, Gao-Feng; Tan, Qun-Zhao; Zhou, Wei-Xing

    2010-02-01

    Massive multiplayer online role-playing games (MMORPGs) have been very popular in the past few years. The profit of an MMORPG company is proportional to how many users registered, and the instant number of online avatars is a key factor to assess how popular an MMORPG is. We use the online-offline logs on an MMORPG server to reconstruct the instant number of online avatars per second and investigate its statistical properties. We find that the online avatar number exhibits one-day periodic behavior and clear intraday pattern, the fluctuation distribution of the online avatar numbers has a leptokurtic non-Gaussian shape with power-law tails, and the increments of online avatar numbers after removing the intraday pattern are uncorrelated and the associated absolute values have long-term correlation. In addition, both time series exhibit multifractal nature.

  19. Parametric statistical inference basic theory and modern approaches

    CERN Document Server

    Zacks, Shelemyahu; Tsokos, C P

    1981-01-01

    Parametric Statistical Inference: Basic Theory and Modern Approaches presents the developments and modern trends in statistical inference to students who do not have advanced mathematical and statistical preparation. The topics discussed in the book are basic and common to many fields of statistical inference and thus serve as a jumping board for in-depth study. The book is organized into eight chapters. Chapter 1 provides an overview of how the theory of statistical inference is presented in subsequent chapters. Chapter 2 briefly discusses statistical distributions and their properties. Chapt

  20. Unusual buffer action of free-standing nanoscopically confined water.

    Science.gov (United States)

    Liao, Kylin; Xu, Xiaozhou; Du, Xuezhong

    2010-01-15

    The acid-base properties of nanoscopic water confined in the black soap films (BSFs), which were prepared from aqueous solutions of sodium dodecylsulphate (SDS) with the dye neutral red (NR) as a pH probe, were investigated using a combination of UV-vis and FTIR spectroscopy. For the SDS micellar solutions at pH 1.0-9.5 adjusted with HCl/NaOH solutions and at pH 9.4 with ammonium buffered solution, the aqueous core thicknesses in the corresponding BSFs ranged from 2.7 to 6.2 nm, and the nanoscopically confined water exhibits unusual buffer action resistant not only to acidic/alkaline solutions but also to standard buffer solution. In the heavily water-depleted confined zones, it is most likely that charge pairs in proton-transfer reactions could not be formed effectively and proton transfer was prohibited in the absence of sufficient solvating ability. Theoretical analyzes indicated that the buffer action of the nanoscopic water originated from the confinement effect of two charged surfaces of the BSFs. These results might inspire deeper understanding and further studies of biobuffering, enzyme superactivity, acid-catalyzed reactions, and Nafion fuel cell membranes.

  1. Unusual Voltage-Gated Sodium Currents as Targets for Pain.

    Science.gov (United States)

    Barbosa, C; Cummins, T R

    2016-01-01

    Pain is a serious health problem that impacts the lives of many individuals. Hyperexcitability of peripheral sensory neurons contributes to both acute and chronic pain syndromes. Because voltage-gated sodium currents are crucial to the transmission of electrical signals in peripheral sensory neurons, the channels that underlie these currents are attractive targets for pain therapeutics. Sodium currents and channels in peripheral sensory neurons are complex. Multiple-channel isoforms contribute to the macroscopic currents in nociceptive sensory neurons. These different isoforms exhibit substantial variations in their kinetics and pharmacology. Furthermore, sodium current complexity is enhanced by an array of interacting proteins that can substantially modify the properties of voltage-gated sodium channels. Resurgent sodium currents, atypical currents that can enhance recovery from inactivation and neuronal firing, are increasingly being recognized as playing potentially important roles in sensory neuron hyperexcitability and pain sensations. Here we discuss unusual sodium channels and currents that have been identified in nociceptive sensory neurons, describe what is known about the molecular determinants of the complex sodium currents in these neurons. Finally, we provide an overview of therapeutic strategies to target voltage-gated sodium currents in nociceptive neurons. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. Statistical analysis of angular correlation measurements

    International Nuclear Information System (INIS)

    Oliveira, R.A.A.M. de.

    1986-01-01

    Obtaining the multipole mixing ratio, δ, of γ transitions in angular correlation measurements is a statistical problem characterized by the small number of angles in which the observation is made and by the limited statistic of counting, α. The inexistence of a sufficient statistics for the estimator of δ, is shown. Three different estimators for δ were constructed and their properties of consistency, bias and efficiency were tested. Tests were also performed in experimental results obtained in γ-γ directional correlation measurements. (Author) [pt

  3. An Unusual Presentation of Myasthenia Gravis | Chijioke | West ...

    African Journals Online (AJOL)

    BACK GROUND: Myasthenia gravis (MG) is generally a rare disorder and may thus be easily misdiagnosed. Misdiagnosis is even more likely when the presentation is atypical. OBJECTIVE: To present and discuss an unusual presentation of myasthenia gravis METHOD: A 67-year-old man presented with progressive ...

  4. Hypothetical views on some unusual disease associations with ...

    African Journals Online (AJOL)

    Sickle cell anemia (SCA) is a disease accompanied with several complications arising mainly from vasoocclusion and haemolysis. There are also complications of infections which may occur due to defective cell mediated and humoral immunity. However, there are associations that have been observed to be unusual in ...

  5. TESTING MODELS OF MAGNETIC FIELD EVOLUTION OF NEUTRON STARS WITH THE STATISTICAL PROPERTIES OF THEIR SPIN EVOLUTIONS

    International Nuclear Information System (INIS)

    Zhang Shuangnan; Xie Yi

    2012-01-01

    We test models for the evolution of neutron star (NS) magnetic fields (B). Our model for the evolution of the NS spin is taken from an analysis of pulsar timing noise presented by Hobbs et al.. We first test the standard model of a pulsar's magnetosphere in which B does not change with time and magnetic dipole radiation is assumed to dominate the pulsar's spin-down. We find that this model fails to predict both the magnitudes and signs of the second derivatives of the spin frequencies (ν-double dot). We then construct a phenomenological model of the evolution of B, which contains a long-term decay (LTD) modulated by short-term oscillations; a pulsar's spin is thus modified by its B-evolution. We find that an exponential LTD is not favored by the observed statistical properties of ν-double dot for young pulsars and fails to explain the fact that ν-double dot is negative for roughly half of the old pulsars. A simple power-law LTD can explain all the observed statistical properties of ν-double dot. Finally, we discuss some physical implications of our results to models of the B-decay of NSs and suggest reliable determination of the true ages of many young NSs is needed, in order to constrain further the physical mechanisms of their B-decay. Our model can be further tested with the measured evolutions of ν-dot and ν-double dot for an individual pulsar; the decay index, oscillation amplitude, and period can also be determined this way for the pulsar.

  6. Unusual events in the use of radioactive material at medical applications

    International Nuclear Information System (INIS)

    Czarwinski, R.

    2002-01-01

    In the Federal Republic of Germany unusual events in the use of radioactive materials and in the operation of accelerators outside the nuclear sector are evaluated centrally and published annually. At that evaluation it can be distinguished between the medical and non-medical application of ionising radiation. Around 3000 user of radioactive materials are registered in medicine including research and teaching. That means approximately 25% of all users in Germany. Firstly an overview on the number of unusual events in the last ten years is given for medical applications like afterloading, gamma irradiation, nuclear medicine, radiation sources and accelerators. The analysis of the incidents in the considered medical areas resulted in two categories-human error and technical break down. The main causes for the incidents which could be analysed are presented in the paper. Additionally the radiation exposures resulting from the incidents are considered. The analysis of these unusual events enables in dependence of the known information lessons learned to avoid similar errors. This feedback will be offered. (Author)

  7. An Unusual Case Report of Erupted Odontoma

    Directory of Open Access Journals (Sweden)

    Dhaval Mehta

    2013-01-01

    Full Text Available Odontomas are the most common of the odontogenic tumors of the jaws, which are benign, slow growing, and nonaggressive. They are usually asymptomatic and found in routine dental radiographic examination. Odontomas are usually associated with tooth eruption disturbances. Eruption of odontoma in oral cavity is rare entity. Here we report a case of an unusual erupted compound odontoma.

  8. Unusual variant of Cantrell′s pentalogy?

    Directory of Open Access Journals (Sweden)

    Kumar Basant

    2008-01-01

    Full Text Available A 12-hour-old male infant presented with prolapsed abdominal content through a defect on left side of chest wall with respiratory distress. A thorough clinical examination suggested absence of ectopia cordis, abdominal wall defect, and any bony anomaly. The child expired after 6 hours of admission because of respiratory distress and electrolyte imbalance. Is congenital defect of chest wall associated with diaphragmatic hernia without ectopia cordis and omphalocele, an unusual variant of Cantrell′s pentalogy?

  9. Unusual intramuscular lipoma of deltoid muscle.

    Science.gov (United States)

    Kapetanakis, Stylianos; Papathanasiou, Jiannis; Dermon, Antonios; Dimitrakopoulou, Alexandra; Ververidis, Athanasios; Chloropoulou, Pelagia; Kazakos, Konstantinos

    2010-01-01

    Lipomas are common soft tissue tumors usually located under the skin. Nevertheless, intramuscular lipomas of deltoid muscle are unusual tumors. We present a case of 74-year-old woman with an intramuscular like clepsydra lipoma of deltoid muscle. The lesion was a palpable soft mass at the lateral side of the humerus. The patient had no previous history of trauma. The main symptom was pain only in abduction and extension. Imaging, pathological findings and surgical excision are discussed.

  10. Wasp sting: An unusual fatal outcome

    International Nuclear Information System (INIS)

    George, P.; Mathew, P.; Pawar, B.; Calton, N.

    2008-01-01

    Wasp stings are not uncommon especially in populations living in theproximity of forested area-s all over the world. Local manifestationsfollowing stings are common and unusually life threatening anaphylaxis mayoccur, requiring prompt treatment. Multi organ failure and acute renalfailure following wasp stings are rare and histological evaluation suggestacute tubular necrosis secondary to hemolysis, rhabdomyolysis and directvenom toxicity. A rare complication of a patient following multiple waspstings with disseminated intravascular coagulation, acute renal failure andthrombotic microangiopathy is presented. (author)

  11. Isotopic evidence for the formation of unusually humus-rich soils in the Baltic region

    Science.gov (United States)

    Leinweber, Peter; Acksel, Andre; Kühn, Peter

    2017-04-01

    Arable mineral soils in the Pleistocene landscape of Northern Germany usually contain about 4 to 8 kg of organic C (Corg) per m2, most of which is visually recognizable concentrated in the tilled topsoil horizon. Some unusually humus-rich (10 to 20 kg Corg m-2), and deeply (> 70 cm) dark-colored soils in coastal regions with mollic properties have been classified as Chernozems. Their location far away from the middle German and Central European Chernozem regions, absence of steppe vegetation and semi-arid climate conditions make classical pedogenetic theories doubtful. However, non-targeted mass spectrometric analyses of soil organic matter (SOM) composition revealed great similarities with typical Chernozems worldwide (Thiele-Bruhn et al., 2014) and made alternative (e.g. waterlogged) pathways of SOM accumulation unlikely. Subsequent detailed multi-method SOM analyses down the soil profiles revealed relative enrichments in cyclic ("black carbon") and heterocyclic organic compounds in the deeper, bioturbated horizons. These were plausibly explained by the input of combustion residues, likely originating from anthropogenic activities because spots of these soils coincided with archeological artifacts of early settlements (Acksel et al., 2016). However, these finding could not completely explain the genesis of Chernozems in the Baltic region. Therefore, we actually explored isotope analyses (12/13C, 13/14C, 14/15N, 32/34S) to find out the origin of these unusual SOM enrichments and the time period in which it occurred. The results will be compiled to a consistent hypothesis on the formation of these soils in the Baltic and other Northern European regions. References Acksel, A., W. Amelung, P. Kühn, E. Gehrt, T. Regier, P. Leinweber. 2016. Soil organic matter characteristics as indicator of Chernozem genesis in the Baltic Sea region. Geoderma Regional 7, 187-200. Thiele-Bruhn, S., Leinweber P., Eckhardt K.-U., Siem H.K., Blume H.-P. 2014. Identifying Chernozem

  12. Properties of permutation-based gene tests and controlling type 1 error using a summary statistic based gene test.

    Science.gov (United States)

    Swanson, David M; Blacker, Deborah; Alchawa, Taofik; Ludwig, Kerstin U; Mangold, Elisabeth; Lange, Christoph

    2013-11-07

    The advent of genome-wide association studies has led to many novel disease-SNP associations, opening the door to focused study on their biological underpinnings. Because of the importance of analyzing these associations, numerous statistical methods have been devoted to them. However, fewer methods have attempted to associate entire genes or genomic regions with outcomes, which is potentially more useful knowledge from a biological perspective and those methods currently implemented are often permutation-based. One property of some permutation-based tests is that their power varies as a function of whether significant markers are in regions of linkage disequilibrium (LD) or not, which we show from a theoretical perspective. We therefore develop two methods for quantifying the degree of association between a genomic region and outcome, both of whose power does not vary as a function of LD structure. One method uses dimension reduction to "filter" redundant information when significant LD exists in the region, while the other, called the summary-statistic test, controls for LD by scaling marker Z-statistics using knowledge of the correlation matrix of markers. An advantage of this latter test is that it does not require the original data, but only their Z-statistics from univariate regressions and an estimate of the correlation structure of markers, and we show how to modify the test to protect the type 1 error rate when the correlation structure of markers is misspecified. We apply these methods to sequence data of oral cleft and compare our results to previously proposed gene tests, in particular permutation-based ones. We evaluate the versatility of the modification of the summary-statistic test since the specification of correlation structure between markers can be inaccurate. We find a significant association in the sequence data between the 8q24 region and oral cleft using our dimension reduction approach and a borderline significant association using the

  13. Radiographic evaluation and unusual bone formations in different genetic patterns in synpolydactyly

    International Nuclear Information System (INIS)

    Yucel, Aylin; Acar, Murat; Kuru, Ilhami; Bozan, M. Eray; Solak, Mustafa

    2005-01-01

    To compare the radiological findings of heterozygous and homozygous subjects with synpolydactyly (SPD) and to discuss their unusual bone formations. Families with hand and foot SPD were examined. Genetic analysis was performed with blood samples and the pedigree was constructed. The affected individuals, especially those with distinctive phenotypic features, were invited to our orthopaedics clinic for further diagnostic studies. All participants underwent detailed clinical and X-ray examinations. Of the invited patients, 16 (five female and 11 male; age range 4-37 years, mean age 10.75 years) were included in our study, and hand and foot radiographs were obtained. All subjects had bilateral hand radiographs (32 hands), and 14 had bilateral foot radiographs (28 feet). Genetic analysis revealed 12 heterozygote (75%) and four (25%) homozygote phenotypes. Among patients enrolled into the study nine (three homozygotes, six heterozygotes) had SPD of both hands and feet bilaterally (tetrasynpolydactyly). Six unusual bone formations were observed in the hands and feet: delta phalanx, delta metacarpal/metatarsal, kissing delta phalanx, true double epiphysis, pseudoepiphysis and cone-shaped epiphysis. There were major differences in radiological and clinical manifestations of homozygote and heterozygote phenotypes. The homozygous SPD presented with very distinctive unusual bone formations. The existence and variety of unusual bones may indicate the severity of penetrance and expressivity of SPD. (orig.)

  14. International Conference on Robust Statistics

    CERN Document Server

    Filzmoser, Peter; Gather, Ursula; Rousseeuw, Peter

    2003-01-01

    Aspects of Robust Statistics are important in many areas. Based on the International Conference on Robust Statistics 2001 (ICORS 2001) in Vorau, Austria, this volume discusses future directions of the discipline, bringing together leading scientists, experienced researchers and practitioners, as well as younger researchers. The papers cover a multitude of different aspects of Robust Statistics. For instance, the fundamental problem of data summary (weights of evidence) is considered and its robustness properties are studied. Further theoretical subjects include e.g.: robust methods for skewness, time series, longitudinal data, multivariate methods, and tests. Some papers deal with computational aspects and algorithms. Finally, the aspects of application and programming tools complete the volume.

  15. Statistics of polarization speckle: theory versus experiment

    DEFF Research Database (Denmark)

    Wang, Wei; Hanson, Steen Grüner; Takeda, Mitsuo

    2010-01-01

    In this paper, we reviewed our recent work on the statistical properties of polarization speckle, described by stochastic Stokes parameters fluctuating in space. Based on the Gaussian assumption for the random electric field components and polar-interferometer, we investigated theoretically...... and experimentally the statistics of Stokes parameters of polarization speckle, including probability density function of Stokes parameters with the spatial degree of polarization, autocorrelation of Stokes vector and statistics of spatial derivatives for Stokes parameters....

  16. A statistical mechanics model for free-for-all airplane passenger boarding

    Science.gov (United States)

    Steffen, Jason H.

    2008-12-01

    I discuss a model for free-for-all passenger boarding which is employed by some discount air carriers. The model is based on the principles of statistical mechanics, where each seat in the aircraft has an associated energy which reflects the preferences of travelers. As each passenger enters the airplane they select their seats using Boltzmann statistics, proceed to that location, load their luggage, sit down, and the partition function seen by remaining passengers is modified to reflect this fact. I discuss the various model parameters and make qualitative comparisons of this passenger boarding model with those that involve assigned seats. The model can be used to predict the probability that certain seats will be occupied at different times during the boarding process. These results might provide a useful description of this boarding method. The model is a relatively unusual application of undergraduate level physics and describes a situation familiar to many students and faculty.

  17. A statistical mechanics model for free-for-all airplane passenger boarding

    International Nuclear Information System (INIS)

    Steffen, Jason H.; Fermilab

    2008-01-01

    I discuss a model for free-for-all passenger boarding which is employed by some discount air carriers. The model is based on the principles of statistical mechanics where each seat in the aircraft has an associated energy which reflects the preferences of travelers. As each passenger enters the airplane they select their seats using Boltzmann statistics, proceed to that location, load their luggage, sit down, and the partition function seen by remaining passengers is modified to reflect this fact. I discuss the various model parameters and make qualitative comparisons of this passenger boarding model with those that involve assigned seats. The model can be used to predict the probability that certain seats will be occupied at different times during the boarding process. These results might provide a useful description of this boarding method. The model is a relatively unusual application of undergraduate level physics and describes a situation familiar to many students and faculty

  18. A statistical mechanics model for free-for-all airplane passenger boarding

    Energy Technology Data Exchange (ETDEWEB)

    Steffen, Jason H.; /Fermilab

    2008-08-01

    I discuss a model for free-for-all passenger boarding which is employed by some discount air carriers. The model is based on the principles of statistical mechanics where each seat in the aircraft has an associated energy which reflects the preferences of travelers. As each passenger enters the airplane they select their seats using Boltzmann statistics, proceed to that location, load their luggage, sit down, and the partition function seen by remaining passengers is modified to reflect this fact. I discuss the various model parameters and make qualitative comparisons of this passenger boarding model with those that involve assigned seats. The model can be used to predict the probability that certain seats will be occupied at different times during the boarding process. These results might provide a useful description of this boarding method. The model is a relatively unusual application of undergraduate level physics and describes a situation familiar to many students and faculty.

  19. Quantum mechanics as applied mathematical statistics

    International Nuclear Information System (INIS)

    Skala, L.; Cizek, J.; Kapsa, V.

    2011-01-01

    Basic mathematical apparatus of quantum mechanics like the wave function, probability density, probability density current, coordinate and momentum operators, corresponding commutation relation, Schroedinger equation, kinetic energy, uncertainty relations and continuity equation is discussed from the point of view of mathematical statistics. It is shown that the basic structure of quantum mechanics can be understood as generalization of classical mechanics in which the statistical character of results of measurement of the coordinate and momentum is taken into account and the most important general properties of statistical theories are correctly respected.

  20. Statistical Assessment of the Effect of Chemical Composition on Mechanical Properties of Hypereutectic AlSi17CuNiMg Silumin

    Directory of Open Access Journals (Sweden)

    J. Szymszal

    2007-07-01

    Full Text Available The paper presents a statistical assessment of the effect of chemical composition on mechanical properties of hypereutectic AlSi17 silumin, which is expected to act as a counterpart of alloys used by automotive industry and aviation for casting of high-duty engine parts in West European countries and USA. The studies on the choice of chemical composition of silumins were preceded by analysis of the reference literature to state what effect some selected alloying elements and manufacturing technology may have on the mechanical properties (HB, Rm and A5 of these alloys. As alloying additives, Cu, Ni and Mg in proper combinations were used. The alloy after modification with phosphorus (CuF was cast into a metal mould. Basing on the results obtained, it has been reported that the developed silumin of hypereutectic composition is characterised by properties similar to its Western counterparts.

  1. Statistical properties of Faraday rotation measure in external galaxies - I. Intervening disc galaxies

    Science.gov (United States)

    Basu, Aritra; Mao, S. A.; Fletcher, Andrew; Kanekar, Nissim; Shukurov, Anvar; Schnitzeler, Dominic; Vacca, Valentina; Junklewitz, Henrik

    2018-06-01

    Deriving the Faraday rotation measure (RM) of quasar absorption line systems, which are tracers of high-redshift galaxies intervening background quasars, is a powerful tool for probing magnetic fields in distant galaxies. Statistically comparing the RM distributions of two quasar samples, with and without absorption line systems, allows one to infer magnetic field properties of the intervening galaxy population. Here, we have derived the analytical form of the probability distribution function (PDF) of RM produced by a single galaxy with an axisymmetric large-scale magnetic field. We then further determine the PDF of RM for one random sight line traversing each galaxy in a population with a large-scale magnetic field prescription. We find that the resulting PDF of RM is dominated by a Lorentzian with a width that is directly related to the mean axisymmetric large-scale field strength of the galaxy population if the dispersion of B0 within the population is smaller than . Provided that RMs produced by the intervening galaxies have been successfully isolated from other RM contributions along the line of sight, our simple model suggests that in galaxies probed by quasar absorption line systems can be measured within ≈50 per cent accuracy without additional constraints on the magneto-ionic medium properties of the galaxies. Finally, we discuss quasar sample selection criteria that are crucial to reliably interpret observations, and argue that within the limitations of the current data base of absorption line systems, high-metallicity damped Lyman-α absorbers are best suited to study galactic dynamo action in distant disc galaxies.

  2. Our experience with unusual gastrointestinal tract duplications in infants

    Directory of Open Access Journals (Sweden)

    Bilal Mirza

    2014-01-01

    Full Text Available Background: Classical duplications may present along any part of gastrointestinal tract (GIT from mouth to anus. Atypical or unusual rare varieties of GIT duplications may also occur, but with different anatomical features. Materials and Methods: We reviewed our 5-year record (February 2008-January 2013 to describe clinical profile of unusual GIT duplications in neonates and small infants. Results: Three patients with atypical variety of GIT duplications were managed in our department during this tenure. Two were females and one male. Age was ranged between 11 days and 2 months. All patients presented with massive abdominal distension causing respiratory embarrassment in two of them. In all patients, the pre-operative differential diagnoses also included GIT duplication cysts. Computerized tomography (CT scan showed single huge cyst in one and multiple cysts in two patients. In one patient the CT scan also depicted a thoracic cyst in relation to posterior mediastinum. At operation, one patient had colonic tubular duplication cyst along with another isolated duplication cyst, the second case had a tubular duplication cyst of ileum with its segmental dilatation, and in the third case two isolated duplications were found. Duplication cysts were excised along with mucosal stripping in one patient, cyst excision and intestinal resection and anastomosis in one patient, and only cysts excision in one. All patients did well post-operatively. Conclusion: We presented unusual GIT duplications. These duplications are managed on similar lines as classical duplications with good prognosis when dealt early.

  3. An unusual etiology of posttraumatic Collet–Sicard Syndrome: a ...

    African Journals Online (AJOL)

    A CT-Scan of the neck was performed demonstrating a fracture of the left styloid process at ... The Magnetic Resonance Imaging showed unusually well seen lower cranial ... Six months after the injury a total neurological recovery was noted.

  4. On the Statistical Properties of Turbulent Energy Transfer Rate in the Inner Heliosphere

    Science.gov (United States)

    Sorriso-Valvo, Luca; Carbone, Francesco; Perri, Silvia; Greco, Antonella; Marino, Raffaele; Bruno, Roberto

    2018-01-01

    The transfer of energy from large to small scales in solar wind turbulence is an important ingredient of the long-standing question of the mechanism of the interplanetary plasma heating. Previous studies have shown that magnetohydrodynamic (MHD) turbulence is statistically compatible with the observed solar wind heating as it expands in the heliosphere. However, in order to understand which processes contribute to the plasma heating, it is necessary to have a local description of the energy flux across scales. To this aim, it is customary to use indicators such as the magnetic field partial variance of increments (PVI), which is associated with the local, relative, scale-dependent magnetic energy. A more complete evaluation of the energy transfer should also include other terms, related to velocity and cross-helicity. This is achieved here by introducing a proxy for the local, scale-dependent turbulent energy transfer rate ɛ_{Δ t}(t), based on the third-order moment scaling law for MHD turbulence. Data from Helios 2 are used to determine the statistical properties of such a proxy in comparison with the magnetic and velocity fields PVI, and the correlation with local solar wind heating is computed. PVI and ɛ_{Δ t}(t) are generally well correlated; however, ɛ_{Δ t}(t) is a very sensitive proxy that can exhibit large amplitude values, both positive and negative, even for low amplitude peaks in the PVI. Furthermore, ɛ_{Δ t}(t) is very well correlated with local increases of the temperature when large amplitude bursts of energy transfer are localized, thus suggesting an important role played by this proxy in the study of plasma energy dissipation.

  5. Unusual cause of coma | Jaggi | Malawi Medical Journal

    African Journals Online (AJOL)

    Journal Home > Vol 8, No 2 (1992) >. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register. Unusual cause of coma. P Jaggi, AD Harries. Abstract. No Abstract. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL ...

  6. Finite-sample instrumental variables inference using an asymptotically pivotal statistic

    NARCIS (Netherlands)

    Bekker, P; Kleibergen, F

    2003-01-01

    We consider the K-statistic, Kleibergen's (2002, Econometrica 70, 1781-1803) adaptation of the Anderson-Rubin (AR) statistic in instrumental variables regression. Whereas Kleibergen (2002) especially analyzes the asymptotic behavior of the statistic, we focus on finite-sample properties in, a

  7. Primary periosteal lymphoma - rare and unusual

    Energy Technology Data Exchange (ETDEWEB)

    Abdelwahab, Ibrahim F. [Coney Island Hospital, Department of Radiology, New York, NY (United States); Hoch, Benjamin [Mount Sinai School of Medicine, CUNY, Department of Pathology, New York, NY (United States); Hermann, George [Mount Sinai School of Medicine, CUNY, Department of Radiology, New York, NY (United States); Bianchi, Stefano [Clinique et Fondation des Grangettes, Geneva (Switzerland); Klein, Michael J. [UAB School of Medicine, Department of Pathology, Birmingham, AL (United States); Springfield, Dempsey S. [Mount Sinai School of Medicine, CUNY, Department of Orthopedics, New York, NY (United States)

    2007-04-15

    We describe a primary periosteal lymphoma that involved only the periosteum without affecting the adjacent medulla or the regional lymph nodes. No other lymphomatous foci were found in either the distant lymph nodes or viscera. This unusual presentation simulates the imaging appearance of surface lesions of bone, namely benign and malignant tumors, and departs from the typical appearance of primary lymphoma of bone. Therefore, this rare type of lymphoma should be considered in the differential diagnosis of surface bone lesions. (orig.)

  8. An unusual presentation of a glomus tumour.

    LENUS (Irish Health Repository)

    Nugent, N

    2011-02-01

    Glomus tumours are benign, soft tissue tumours, usually of fingertips. Classically they present with severe pain, temperature sensitivity and localised tenderness. The diagnosis is often delayed due to sometimes non-specific symptoms and rarity of the disorder. While usually a clinical diagnosis, imaging may be necessary for diagnosis and localisation. We present a case of glomus tumour of the fingertip with an unusual history.

  9. Diagnostic considerations concerning a case of an unusual gingivitis

    NARCIS (Netherlands)

    van der Haring, I.S.; Witjes, M.J.H.

    2006-01-01

    A young woman presented a severe gingivitis that wouldn't respond to antibiotics prescribed by her general practitioner. Thorough clinical examination showed atypical gingival inflammation. In such unusual cases a careful anamnesis is essential in determining appropriate continued diagnostic

  10. Statistics of natural binaural sounds.

    Directory of Open Access Journals (Sweden)

    Wiktor Młynarski

    Full Text Available Binaural sound localization is usually considered a discrimination task, where interaural phase (IPD and level (ILD disparities at narrowly tuned frequency channels are utilized to identify a position of a sound source. In natural conditions however, binaural circuits are exposed to a stimulation by sound waves originating from multiple, often moving and overlapping sources. Therefore statistics of binaural cues depend on acoustic properties and the spatial configuration of the environment. Distribution of cues encountered naturally and their dependence on physical properties of an auditory scene have not been studied before. In the present work we analyzed statistics of naturally encountered binaural sounds. We performed binaural recordings of three auditory scenes with varying spatial configuration and analyzed empirical cue distributions from each scene. We have found that certain properties such as the spread of IPD distributions as well as an overall shape of ILD distributions do not vary strongly between different auditory scenes. Moreover, we found that ILD distributions vary much weaker across frequency channels and IPDs often attain much higher values, than can be predicted from head filtering properties. In order to understand the complexity of the binaural hearing task in the natural environment, sound waveforms were analyzed by performing Independent Component Analysis (ICA. Properties of learned basis functions indicate that in natural conditions soundwaves in each ear are predominantly generated by independent sources. This implies that the real-world sound localization must rely on mechanisms more complex than a mere cue extraction.

  11. Statistics of natural binaural sounds.

    Science.gov (United States)

    Młynarski, Wiktor; Jost, Jürgen

    2014-01-01

    Binaural sound localization is usually considered a discrimination task, where interaural phase (IPD) and level (ILD) disparities at narrowly tuned frequency channels are utilized to identify a position of a sound source. In natural conditions however, binaural circuits are exposed to a stimulation by sound waves originating from multiple, often moving and overlapping sources. Therefore statistics of binaural cues depend on acoustic properties and the spatial configuration of the environment. Distribution of cues encountered naturally and their dependence on physical properties of an auditory scene have not been studied before. In the present work we analyzed statistics of naturally encountered binaural sounds. We performed binaural recordings of three auditory scenes with varying spatial configuration and analyzed empirical cue distributions from each scene. We have found that certain properties such as the spread of IPD distributions as well as an overall shape of ILD distributions do not vary strongly between different auditory scenes. Moreover, we found that ILD distributions vary much weaker across frequency channels and IPDs often attain much higher values, than can be predicted from head filtering properties. In order to understand the complexity of the binaural hearing task in the natural environment, sound waveforms were analyzed by performing Independent Component Analysis (ICA). Properties of learned basis functions indicate that in natural conditions soundwaves in each ear are predominantly generated by independent sources. This implies that the real-world sound localization must rely on mechanisms more complex than a mere cue extraction.

  12. A solitary bronchial papilloma with unusual endoscopic presentation: case study and literature review

    Directory of Open Access Journals (Sweden)

    Frejeville Marie

    2009-08-01

    Full Text Available Abstract Background Solitary endobronchial papillomas (SEP are rare tumors and most of them are described by case report. A misdiagnosis is common with viral related papillomas. A histopathological classification has recently permitted a major advancement in the understanding of the disease. Case Presentation We report a case of a mixed bronchial papilloma with an unusual endoscopic presentation. The literature was extensively reviewed to ascertain the unusual characteristics of the current case. A 39-year of age male was referred to our institution for the investigation of a slight hemoptysis. Routine examination was normal. A fibroscopy revealed an unusual feature of the right main bronchus. The lesion was a plane, non-bleeding, non-glistering sub-mucosal proliferation. No enhanced coloration was noticed. Biopsies revealed a mixed solitary bronchial papilloma. In situ HPV hybridization was negative. Endoscopic treatment (electrocautery was effective with no relapse. Conclusion This lesion contrasts with the data of the literature where papilloma were described as wart-like lesions or cauliflower tumors, with symptoms generally related to bronchial obstruction. We advise chest physicians to be cautious with unusually small swollen lesions of the bronchi that may reveal a solitary bronchial papilloma. Endoscopic imaging can significantly contribute to the difficult diagnosis of SEP by pulmonary physicians and endoscopists.

  13. Some statistical properties of gene expression clustering for array data

    DEFF Research Database (Denmark)

    Abreu, G C G; Pinheiro, A; Drummond, R D

    2010-01-01

    DNA array data without a corresponding statistical error measure. We propose an easy-to-implement and simple-to-use technique that uses bootstrap re-sampling to evaluate the statistical error of the nodes provided by SOM-based clustering. Comparisons between SOM and parametric clustering are presented...... for simulated as well as for two real data sets. We also implement a bootstrap-based pre-processing procedure for SOM, that improves the false discovery ratio of differentially expressed genes. Code in Matlab is freely available, as well as some supplementary material, at the following address: https...

  14. Original article Urethral Stricture and HIV: Unusual Presentations ...

    African Journals Online (AJOL)

    mn

    cause of urethral stricture in this series was traumatic injury The other important cause was post-inflammatory (after gonococcal urethritis) with HIV co-infection. These patients posed a challenge due to our lack of experience and the absence of literature guidelines on the optimal management. The first unusual feature in the ...

  15. Spinal Metastasis Of Wilm's Tumuor: An Unusual Occurrence ...

    African Journals Online (AJOL)

    Background: Metastasis of the Wilm's tumor is usually to surrounding tissue, the lungs and the liver. Rarely is there spread to bone, bone-marrow, spinal canal and other tissues, but this unusual mode of spread sometimes occurs. Objectives: To report a case of Wilm's tumuor complicated by spastic paraplegia consequent to ...

  16. Unusual Presentation of Meningitis following Stab Neck | Motsitsi ...

    African Journals Online (AJOL)

    Background: A case report of stab neck presenting at Kalafong Hospital, Pretoria, South Africa with atypical meningitis. The objective was to illustrate the challenge of diagnosing this unusual and late presentation of meningitis. Case Report: A 48 year-old male patient presented to us two days after a stab neck. He was ...

  17. endodontic treatment of unusually long discolored maxillary central ...

    African Journals Online (AJOL)

    a few cases of dual–rooted maxillary central incisor have been reported in literature1-5. Maxillary central incisors vary in root ... The following case report describes the endodontic management of a patient with an unusually long maxillary central incisor in our environment. CASE PROFILE. A 31 year-old male was referred ...

  18. Statistics a guide to the use of statistical methods in the physical sciences

    CERN Document Server

    Barlow, Roger J

    1989-01-01

    The Manchester Physics Series General Editors: D. J. Sandiford; F. Mandl; A. C. Phillips Department of Physics and Astronomy, University of Manchester Properties of Matter B. H. Flowers and E. Mendoza Optics Second Edition F. G. Smith and J. H. Thomson Statistical Physics Second Edition F. Mandl Electromagnetism Second Edition I. S. Grant and W. R. Phillips Statistics R. J. Barlow Solid State Physics Second Edition J. R. Hook and H. E. Hall Quantum Mechanics F. Mandl Particle Physics Second Edition B. R. Martin and G. Shaw The Physics of Stars Second Edition A.C. Phillips Computing for Scienti

  19. Powerful Statistical Inference for Nested Data Using Sufficient Summary Statistics

    Science.gov (United States)

    Dowding, Irene; Haufe, Stefan

    2018-01-01

    Hierarchically-organized data arise naturally in many psychology and neuroscience studies. As the standard assumption of independent and identically distributed samples does not hold for such data, two important problems are to accurately estimate group-level effect sizes, and to obtain powerful statistical tests against group-level null hypotheses. A common approach is to summarize subject-level data by a single quantity per subject, which is often the mean or the difference between class means, and treat these as samples in a group-level t-test. This “naive” approach is, however, suboptimal in terms of statistical power, as it ignores information about the intra-subject variance. To address this issue, we review several approaches to deal with nested data, with a focus on methods that are easy to implement. With what we call the sufficient-summary-statistic approach, we highlight a computationally efficient technique that can improve statistical power by taking into account within-subject variances, and we provide step-by-step instructions on how to apply this approach to a number of frequently-used measures of effect size. The properties of the reviewed approaches and the potential benefits over a group-level t-test are quantitatively assessed on simulated data and demonstrated on EEG data from a simulated-driving experiment. PMID:29615885

  20. Quantum mechanics from classical statistics

    International Nuclear Information System (INIS)

    Wetterich, C.

    2010-01-01

    Quantum mechanics can emerge from classical statistics. A typical quantum system describes an isolated subsystem of a classical statistical ensemble with infinitely many classical states. The state of this subsystem can be characterized by only a few probabilistic observables. Their expectation values define a density matrix if they obey a 'purity constraint'. Then all the usual laws of quantum mechanics follow, including Heisenberg's uncertainty relation, entanglement and a violation of Bell's inequalities. No concepts beyond classical statistics are needed for quantum physics - the differences are only apparent and result from the particularities of those classical statistical systems which admit a quantum mechanical description. Born's rule for quantum mechanical probabilities follows from the probability concept for a classical statistical ensemble. In particular, we show how the non-commuting properties of quantum operators are associated to the use of conditional probabilities within the classical system, and how a unitary time evolution reflects the isolation of the subsystem. As an illustration, we discuss a classical statistical implementation of a quantum computer.

  1. Photoinduced quantum magnetotransport properties of silicene and germanene

    KAUST Repository

    Tahir, Muhammad

    2015-10-30

    Silicene and germanene have remarkable electronic properties due to strong spin orbit coupling and buckled single layer structures. We derive and analyze the band structures of these materials in the presence of perpendicular electric and magnetic fields taking into account the effects of off-resonant light. Using linear response theory, analytical expressions are derived and evaluated for the Hall and longitudinal conductivities. Contrary to graphene, we show that the light leads to a single Dirac cone state and thus to unusual plateaus and magnetotransport properties, which are desirable for electronic applications.

  2. Quasiparticle features and level statistics of odd-odd nucleus

    International Nuclear Information System (INIS)

    Cheng Nanpu; Zheng Renrong; Zhu Shunquan

    2001-01-01

    The energy levels of the odd-odd nucleus 84 Y are calculated by using the axially symmetric rotor plus quasiparticles model. The two standard statistical tests of Random-Matrix Theory such as the distribution function p(s) of the nearest-neighbor level spacings (NNS) and the spectral rigidity Δ 3 are used to explore the statistical properties of the energy levels. By analyzing the properties of p(s) and Δ 3 under various conditions, the authors find that the quasiparticle features mainly affect the statistical properties of the odd-odd nucleus 84 Y through the recoil term and the Coriolis force in this theoretical mode, and that the chaotic degree of the energy levels decreases with the decreasing of the Fermi energy and the energy-gap parameters. The effect of the recoil term is small while the Coriolis force plays a major role in the spectral structure of 84 Y

  3. Unusual bond paths in organolithium compounds

    International Nuclear Information System (INIS)

    Bachrach, S.M.; Ritchie, J.P.

    1986-01-01

    We have applied the topological method to a number of organolithium compounds. The wavefunctions were determined with GAUSSIAN-82 using 3-21G basis set and fully optimized geometries. Gradient paths were obtained using the RHODER package and critical points were located using EXTREME. These results indicate the unusual nature of organolithium compounds. The strange bond paths arise mainly from the ionic nature of the C-Li interaction. We suggest that the term ''bond path'' may best be suited for covalent bonds. 4 figs., 1 tab

  4. An unusual presentation of testicular tumor

    International Nuclear Information System (INIS)

    Amin, M.U.; Rahan, T.; Haq, A.U.; Aftab, P.

    2006-01-01

    A case of testicular choriocarcinoma is reported in which blood mixed stools and haemoptysis were the presenting manifestations as the patient never told about the testicular swelling to his parents. Orchidectomy was performed but the patient presented again with massive hematemesis due to gastric perforation secondary to gastric metastasis. The size of the testis at diagnosis was approximately 12 x 7cm. This was also unusual as testicular choriocarcinoma presents as a small mass. The patient eventually died of the complications within one month of diagnosis. (author)

  5. Distinctive receptor binding properties of the surface glycoprotein of a natural Feline Leukemia Virus isolate with unusual disease spectrum

    Directory of Open Access Journals (Sweden)

    Albritton Lorraine M

    2011-05-01

    Full Text Available Abstract Background Feline leukemia virus (FeLV-945, a member of the FeLV-A subgroup, was previously isolated from a cohort of naturally infected cats. An unusual multicentric lymphoma of non-T-cell origin was observed in natural and experimental infection with FeLV-945. Previous studies implicated the FeLV-945 surface glycoprotein (SU as a determinant of disease outcome by an as yet unknown mechanism. The present studies demonstrate that FeLV-945 SU confers distinctive properties of binding to the cell surface receptor. Results Virions bearing the FeLV-945 Env protein were observed to bind the cell surface receptor with significantly increased efficiency, as was soluble FeLV-945 SU protein, as compared to the corresponding virions or soluble protein from a prototype FeLV-A isolate. SU proteins cloned from other cohort isolates exhibited increased binding efficiency comparable to or greater than FeLV-945 SU. Mutational analysis implicated a domain containing variable region B (VRB to be the major determinant of increased receptor binding, and identified a single residue, valine 186, to be responsible for the effect. Conclusions The FeLV-945 SU protein binds its cell surface receptor, feTHTR1, with significantly greater efficiency than does that of prototype FeLV-A (FeLV-A/61E when present on the surface of virus particles or in soluble form, demonstrating a 2-fold difference in the relative dissociation constant. The results implicate a single residue, valine 186, as the major determinant of increased binding affinity. Computational modeling suggests a molecular mechanism by which residue 186 interacts with the receptor-binding domain through residue glutamine 110 to effect increased binding affinity. Through its increased receptor binding affinity, FeLV-945 SU might function in pathogenesis by increasing the rate of virus entry and spread in vivo, or by facilitating entry into a novel target cell with a low receptor density.

  6. Uniportal anatomic combined unusual segmentectomies.

    Science.gov (United States)

    González-Rivas, Diego; Lirio, Francisco; Sesma, Julio

    2017-01-01

    Nowadays, sublobar anatomic resections are gaining momentum as a valid alternative for early stage lung cancer. Despite being technically demanding, anatomic segmentectomies can be performed by uniportal video-assisted thoracic surgery (VATS) approach to combine the benefits of minimally invasiveness with the maximum lung sparing. This procedure can be even more complex if a combined resection of multiple segments from different lobes has to be done. Here we report five cases of combined and unusual segmentectomies done by the same experienced surgeon in high volume institutions to show uniportal VATS is a feasible approach for these complex resections and to share an excellent educational resource.

  7. Unusual magnetoresistance in cubic B20 Fe0.85Co0.15Si chiral magnets

    Science.gov (United States)

    Huang, S. X.; Chen, Fei; Kang, Jian; Zang, Jiadong; Shu, G. J.; Chou, F. C.; Chien, C. L.

    2016-06-01

    The B20 chiral magnets with broken inversion symmetry and C4 rotation symmetry have attracted much attention. The broken inversion symmetry leads to the Dzyaloshinskii-Moriya that gives rise to the helical and Skyrmion states. We report the unusual magnetoresistance (MR) of B20 chiral magnet Fe0.85Co0.15Si that directly reveals the broken C4 rotation symmetry and shows the anisotropic scattering by Skyrmions with respect to the current directions. The intimacy between unusual MR and broken symmetry is well confirmed by theoretically studying an effective Hamiltonian with spin-orbit coupling. The unusual MR serves as a transport signature for the Skyrmion phase.

  8. Unusual magnetoresistance in cubic B20 Fe0.85Co0.15Si chiral magnets

    International Nuclear Information System (INIS)

    Huang, S X; Chen, Fei; Zang, Jiadong; Chien, C L; Kang, Jian; Shu, G J; Chou, F C

    2016-01-01

    The B20 chiral magnets with broken inversion symmetry and C 4 rotation symmetry have attracted much attention. The broken inversion symmetry leads to the Dzyaloshinskii–Moriya that gives rise to the helical and Skyrmion states. We report the unusual magnetoresistance (MR) of B20 chiral magnet Fe 0.85 Co 0.15 Si that directly reveals the broken C 4 rotation symmetry and shows the anisotropic scattering by Skyrmions with respect to the current directions. The intimacy between unusual MR and broken symmetry is well confirmed by theoretically studying an effective Hamiltonian with spin–orbit coupling. The unusual MR serves as a transport signature for the Skyrmion phase. (paper)

  9. Purulent meningitis with unusual diffusion-weighted MRI findings

    International Nuclear Information System (INIS)

    Abe, M.; Takayama, Y.; Yamashita, H.; Noguchi, M.; Sagoh, T.

    2002-01-01

    We describe unusual findings obtained by diffusion-weighted magnetic resonance imaging (MRI) in a patient with acute purulent meningitis caused by penicillin-resistant Streptococcus pneumoniae. Along cerebral convexities and the Sylvian fissure, multiple small intense lesions showed high signal intensity in these sequences. This may be the first report of diffusion-weighted in purulent meningitis

  10. Unusual near-band-edge photoluminescence at room temperature in heavily-doped ZnO:Al thin films prepared by pulsed laser deposition

    International Nuclear Information System (INIS)

    Mohanty, Bhaskar Chandra; Yeon, Deuk Ho; Das, Sachindra Nath; Kwak, Ji Hye; Yoon, Kyung Hoon; Cho, Yong Soo

    2013-01-01

    Room temperature photoluminescence (PL) properties of heavily-doped ZnO:Al thin films (with carrier concentration n in the range of 5–20 × 10 20 cm −3 ) prepared by pulsed laser deposition have been investigated. Despite their high carrier concentration, the films exhibited strong room temperature near-band-edge bound excitons at ∼3.34 eV and an unusual peak at ∼3.16 eV, and negligible deep-level emission even for the films deposited at a temperature as low as 25 °C. The radiative efficiency of the films increased with growth temperature as a result of increased n and improved crystallinity. A large blue shift of optical band gap was observed, which is consistent with the n-dependent Burstein–Moss and band gap-renormalization effects. Comparison of the results of the PL and optical measurements revealed a large Stokes shift that increased with increase in n. It has been explained by a model based on local potential fluctuations caused by randomly-distributed doping impurities. - Highlights: • Studied PL properties of heavily-doped ZnO:Al films grown by PLD. • Unusual strong near-band-edge emissions and negligible deep-level emission at RT. • Increased optical band gap with growth temperature and thus carrier concentration. • Stokes shift and PL peak width increased with carrier concentration. • Results explained by a model based on local potential fluctuations

  11. An unusual presentation of juvenile lupus nephritis

    Directory of Open Access Journals (Sweden)

    Malleshwar Bottu

    2016-01-01

    Full Text Available The incidence of juvenile lupus varies widely ranging between 4 and 250 per 100,000 population. Most common organ involvement in juvenile lupus is kidney. Neurological, cutaneous and hematological involvements are also involved. Skeletal muscle involvement in the form of myositis is rare. Myositis as presenting manifestation in juvenile lupus is also unusual. Herein, we report one such case wherein myositis preceded the onset of lupus nephritis

  12. An unusual cause of anemia and encephalopathy

    Directory of Open Access Journals (Sweden)

    Sanjeev Kumar Sharma

    2015-04-01

    Full Text Available The authors present here an interesting case of recent onset anemia that was associated with an encephalopathy of the unusual cause.Although severe anemia can theoretically result in anemic hypoxia and can then lead to hypoxic encephalopathy, it is not a primary cause of encephalopathy. More frequently anemia can contribute together with other multiple causes of encephalopathy, such as infections, metabolic abnormalities, trauma, hepatic dysfunction, hypertension, toxins.

  13. Primary malignant peripheral nerve sheath tumor at unusual location

    Directory of Open Access Journals (Sweden)

    Souvagya Panigrahi

    2013-01-01

    Full Text Available Malignant peripheral nerve sheath tumor (MPNST is a rare soft tissue sarcoma. Most arise in association with major nerve trunks. Their most common anatomical sites are the proximal portions of the upper and lower extremities and the trunk. MPNSTs have rarely been reported in literature to occur in other unusual body parts. We review all such cases reported till now in terms of site of origin, surgical treatment, adjuvant therapy and outcome and shortly describe our experience with two of these cases. Both of our case presented with lump at unusual sites resembling neurofibroma, one at orbitotemporal area and other in the paraspinal region with characteristic feature of neurofibroma with the exception that both had very short history of progression. They underwent gross total removal of the tumor with adjuvant radiotherapy postoperatively. At 6-month follow-up both are doing well with no evidence of recurrence.

  14. Statistics of resonances and time reversal reconstruction in aluminum acoustic chaotic cavities

    NARCIS (Netherlands)

    Antoniuk, O.; Sprik, R.

    2010-01-01

    The statistical properties of wave propagation in classical chaotic systems are of fundamental interest in physics and are the basis for diagnostic tools in materials science. The statistical properties depend in particular also on the presence of time reversal invariance in the system, which can be

  15. UNUSUALLY WIDE BINARIES: ARE THEY WIDE OR UNUSUAL?

    International Nuclear Information System (INIS)

    Kraus, Adam L.; Hillenbrand, Lynne A.

    2009-01-01

    We describe an astrometric and spectroscopic campaign to confirm the youth and association of a complete sample of candidate wide companions in Taurus and Upper Sco. Our survey found 15 new binary systems (three in Taurus and 12 in Upper Sco) with separations of 3''-30'' (500-5000 AU) among all of the known members with masses of 2.5-0.012 M sun . The total sample of 49 wide systems in these two regions conforms to only some expectations from field multiplicity surveys. Higher mass stars have a higher frequency of wide binary companions, and there is a marked paucity of wide binary systems near the substellar regime. However, the separation distribution appears to be log-flat, rather than declining as in the field, and the mass ratio distribution is more biased toward similar-mass companions than the initial mass function or the field G-dwarf distribution. The maximum separation also shows no evidence of a limit at ∼ sun . We attribute this result to the post-natal dynamical sculpting that occurs for most field systems; our binary systems will escape to the field intact, but most field stars are formed in denser clusters and undergo significant dynamical evolution. In summary, only wide binary systems with total masses ∼ sun appear to be 'unusually wide'.

  16. Distinguish Dynamic Basic Blocks by Structural Statistical Testing

    DEFF Research Database (Denmark)

    Petit, Matthieu; Gotlieb, Arnaud

    Statistical testing aims at generating random test data that respect selected probabilistic properties. A distribution probability is associated with the program input space in order to achieve statistical test purpose: to test the most frequent usage of software or to maximize the probability of...... control flow path) during the test data selection. We implemented this algorithm in a statistical test data generator for Java programs. A first experimental validation is presented...

  17. Statistical methods to monitor the West Valley off-gas system

    International Nuclear Information System (INIS)

    Eggett, D.L.

    1990-01-01

    This paper reports on the of-gas system for the ceramic melter operated at the West Valley Demonstration Project at West Valley, NY, monitored during melter operation. A one-at-a-time method of monitoring the parameters of the off-gas system is not statistically sound. Therefore, multivariate statistical methods appropriate for the monitoring of many correlated parameters will be used. Monitoring a large number of parameters increases the probability of a false out-of-control signal. If the parameters being monitored are statistically independent, the control limits can be easily adjusted to obtain the desired probability of a false out-of-control signal. The principal component (PC) scores have desirable statistical properties when the original variables are distributed as multivariate normals. Two statistics derived from the PC scores and used to form multivariate control charts are outlined and their distributional properties reviewed

  18. Carbohydrate Metabolism in Archaea: Current Insights into Unusual Enzymes and Pathways and Their Regulation

    Science.gov (United States)

    Esser, Dominik; Rauch, Bernadette

    2014-01-01

    SUMMARY The metabolism of Archaea, the third domain of life, resembles in its complexity those of Bacteria and lower Eukarya. However, this metabolic complexity in Archaea is accompanied by the absence of many “classical” pathways, particularly in central carbohydrate metabolism. Instead, Archaea are characterized by the presence of unique, modified variants of classical pathways such as the Embden-Meyerhof-Parnas (EMP) pathway and the Entner-Doudoroff (ED) pathway. The pentose phosphate pathway is only partly present (if at all), and pentose degradation also significantly differs from that known for bacterial model organisms. These modifications are accompanied by the invention of “new,” unusual enzymes which cause fundamental consequences for the underlying regulatory principles, and classical allosteric regulation sites well established in Bacteria and Eukarya are lost. The aim of this review is to present the current understanding of central carbohydrate metabolic pathways and their regulation in Archaea. In order to give an overview of their complexity, pathway modifications are discussed with respect to unusual archaeal biocatalysts, their structural and mechanistic characteristics, and their regulatory properties in comparison to their classic counterparts from Bacteria and Eukarya. Furthermore, an overview focusing on hexose metabolic, i.e., glycolytic as well as gluconeogenic, pathways identified in archaeal model organisms is given. Their energy gain is discussed, and new insights into different levels of regulation that have been observed so far, including the transcript and protein levels (e.g., gene regulation, known transcription regulators, and posttranslational modification via reversible protein phosphorylation), are presented. PMID:24600042

  19. Northern Gulf of Mexico Marine Mammal Unusual Mortality Event Database

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Tissues and samples collected from marine mammals during investigation of the Northern Gulf of Mexico Marine Mammal Unusual Mortality Event are tracked within this...

  20. Application of Ontology Technology in Health Statistic Data Analysis.

    Science.gov (United States)

    Guo, Minjiang; Hu, Hongpu; Lei, Xingyun

    2017-01-01

    Research Purpose: establish health management ontology for analysis of health statistic data. Proposed Methods: this paper established health management ontology based on the analysis of the concepts in China Health Statistics Yearbook, and used protégé to define the syntactic and semantic structure of health statistical data. six classes of top-level ontology concepts and their subclasses had been extracted and the object properties and data properties were defined to establish the construction of these classes. By ontology instantiation, we can integrate multi-source heterogeneous data and enable administrators to have an overall understanding and analysis of the health statistic data. ontology technology provides a comprehensive and unified information integration structure of the health management domain and lays a foundation for the efficient analysis of multi-source and heterogeneous health system management data and enhancement of the management efficiency.

  1. Ruptured rectal duplication with urogenital abnormality: Unusual presentation.

    Science.gov (United States)

    Solanki, Shailesh; Babu, M Narendra; Jadhav, Vinay; Shankar, Gowri; Santhanakrishnan, Ramesh

    2015-01-01

    Rectal duplication (RD) accounts for 5% of alimentary tract duplication. A varied presentation and associated anomalies have been described in the literature. Antenatal rupture of the RD is very rare. We present an unusual case of a ruptured RD associated with urogenital abnormalities in newborn male. We are discussing diagnosis, embryology, management and literature review of ruptured RD.

  2. An unusual presentation of toothpick penetration of colon

    OpenAIRE

    Wani, Imtiaz; Wani, Shamima A; Mir, Shabir; Parra, Khursheed

    2010-01-01

    This case report presents the delayed unusual presentation of plastic toothpick penetrating transverse colon 3 months after ingestion with localized peritonitis. Role of omentum "policeman of abdomen" for salvage is highlighted. Careful observation and long-term lookup for any neglected ingested foreign body are stressed. The delayed presentation can be sometimes proving as a surgical emergency.

  3. An unusual presentation of toothpick penetration of colon

    Directory of Open Access Journals (Sweden)

    Wani Imtiaz

    2010-01-01

    Full Text Available This case report presents the delayed unusual presentation of plastic toothpick penetrating transverse colon 3 months after ingestion with localized peritonitis. Role of omentum "policeman of abdomen" for salvage is highlighted. Careful observation and long-term lookup for any neglected ingested foreign body are stressed. The delayed presentation can be sometimes proving as a surgical emergency.

  4. An unusual foreign body in the preputial sac.

    Science.gov (United States)

    Jaiswal, A K

    1992-01-01

    A 28 year old Indian male presented with an unusual foreign body, a penicillin bottle containing tincture of iodine, in the preputial sac. The purpose of introducing the bottle was to tickle his glans penis as a form of masturbation. The bottle was so firmly impacted that it could be removed only under general anaesthesia. Images PMID:1427809

  5. Spondylo-megaepiphyseal-metaphyseal dysplasia: an unusual bone dysplasia

    International Nuclear Information System (INIS)

    Agarwal, Prachi Pragya; Srinivasan, Ashok; Sharma, Raju; Gupta, Arun Kumar; Kabra, Madhulika

    2003-01-01

    A rare case of spondylo-megaepiphyseal-metaphyseal dysplasia is reported in a 10-year-old boy. The features were metaphyseal dysplasia, markedly defective ossification of vertebral body centres and enlarged epiphyses. Although it shares some features with spondylo-metaphyseal dysplasia, oto-spondylo-megaepiphyseal dysplasia and cleidocranial dysplasia, the presence of several unusual radiological findings sets it apart. (orig.)

  6. Hepatobiliary fascioliasis: a case with unusual radiological features.

    Science.gov (United States)

    Yeşildağ, Ahmet; Senol, Altuğ; Köroğlu, Mert; Koçkar, Cem; Oyar, Orhan; Işler, Mehmet

    2010-12-01

    We report a case of hepatobiliary fascioliasis presenting with unusual radiological findings that have not been reported previously. Imaging studies revealed hepatic cystic pouches communicating with intrahepatic bile ducts. Snail-like, oval shaped and conglomerated echogenic particles with no acoustic shadowing, suggesting F. hepatica, were detected in these cystic pouches. In addition, secondary sclerosing cholangitis developed after fascioliasis.

  7. Statistical Comparison of the Baseline Mechanical Properties of NBG-18 and PCEA Graphite

    Energy Technology Data Exchange (ETDEWEB)

    Mark C. Carroll; David T. Rohrbaugh

    2013-08-01

    High-purity graphite is the core structural material of choice in the Very High Temperature Reactor (VHTR), a graphite-moderated, helium-cooled design that is capable of producing process heat for power generation and for industrial process that require temperatures higher than the outlet temperatures of present nuclear reactors. The Baseline Graphite Characterization Program is endeavoring to minimize the conservative estimates of as-manufactured mechanical and physical properties by providing comprehensive data that captures the level of variation in measured values. In addition to providing a comprehensive comparison between these values in different nuclear grades, the program is also carefully tracking individual specimen source, position, and orientation information in order to provide comparisons and variations between different lots, different billets, and different positions from within a single billet. This report is a preliminary comparison between the two grades of graphite that were initially favored in the two main VHTR designs. NBG-18, a medium-grain pitch coke graphite from SGL formed via vibration molding, was the favored structural material in the pebble-bed configuration, while PCEA, a smaller grain, petroleum coke, extruded graphite from GrafTech was favored for the prismatic configuration. An analysis of the comparison between these two grades will include not only the differences in fundamental and statistically-significant individual strength levels, but also the differences in variability in properties within each of the grades that will ultimately provide the basis for the prediction of in-service performance. The comparative performance of the different types of nuclear grade graphites will continue to evolve as thousands more specimens are fully characterized from the numerous grades of graphite being evaluated.

  8. Statistical properties of Faraday rotation measure in external galaxies - I: intervening disc galaxies

    Science.gov (United States)

    Basu, Aritra; Mao, S. A.; Fletcher, Andrew; Kanekar, Nissim; Shukurov, Anvar; Schnitzeler, Dominic; Vacca, Valentina; Junklewitz, Henrik

    2018-03-01

    Deriving the Faraday rotation measure (RM) of quasar absorption line systems, which are tracers of high-redshift galaxies intervening background quasars, is a powerful tool for probing magnetic fields in distant galaxies. Statistically comparing the RM distributions of two quasar samples, with and without absorption line systems, allows one to infer magnetic field properties of the intervening galaxy population. Here, we have derived the analytical form of the probability distribution function (PDF) of RM produced by a single galaxy with an axisymmetric large-scale magnetic field. We then further determine the PDF of RM for one random sight line traversing each galaxy in a population with a large-scale magnetic field prescription. We find that the resulting PDF of RM is dominated by a Lorentzian with a width that is directly related to the mean axisymmetric large-scale field strength ⟨B0⟩ of the galaxy population if the dispersion of B0 within the population is smaller than ⟨B0⟩. Provided that RMs produced by the intervening galaxies have been successfully isolated from other RM contributions along the line of sight, our simple model suggests that ⟨B0⟩ in galaxies probed by quasar absorption line systems can be measured within ≈50 per cent accuracy without additional constraints on the magneto-ionic medium properties of the galaxies. Finally, we discuss quasar sample selection criteria that are crucial to reliably interpret observations, and argue that within the limitations of the current database of absorption line systems, high-metallicity damped Lyman-α absorbers are best suited to study galactic dynamo action in distant disc galaxies.

  9. Unusual blunt force wound produced by a gun muzzle.

    Science.gov (United States)

    Hanzlick, R; Zaki, S A

    1986-09-01

    Most blunt force injuries produced by guns are associated with gun butts, and patterned, muzzle/sight impressions are usually produced by discharging firearms. An unusual and distinct forehead laceration produced by a blow with the muzzle end of a .32 caliber revolver is presented.

  10. Brownian quasi-particles in statistical physics

    International Nuclear Information System (INIS)

    Tellez-Arenas, A.; Fronteau, J.; Combis, P.

    1979-01-01

    The idea of a Brownian quasi-particle and the associated differentiable flow (with nonselfadjoint forces) are used here in the context of a stochastic description of the approach towards statistical equilibrium. We show that this quasi-particle flow acquires, at equilibrium, the principal properties of a conservative Hamiltonian flow. Thus the model of Brownian quasi-particles permits us to establish a link between the stochastic description and the Gibbs description of statistical equilibrium

  11. Unusual 4-hydroxybenzaldehyde synthase activity from tissue cultures of the vanilla orchid Vanilla planifolia.

    Science.gov (United States)

    Podstolski, Andrzej; Havkin-Frenkel, Daphna; Malinowski, Jacek; Blount, Jack W; Kourteva, Galina; Dixon, Richard A

    2002-11-01

    Tissue cultures of the vanilla orchid, Vanilla planifolia, produce the flavor compound vanillin (4-hydroxy-3-methoxybenzaldehyde) and vanillin precursors such as 4-hydroxybenzaldehyde. A constitutively expressed enzyme activity catalyzing chain shortening of a hydroxycinnamic acid, believed to be the first reaction specific for formation of vanilla flavor compounds, was identified in these cultures. The enzyme converts 4-coumaric acid non-oxidatively to 4-hydroxybenzaldehyde in the presence of a thiol reagent but with no co-factor requirement. Several forms of this 4-hydroxybenzaldehyde synthase (4HBS) were resolved and partially purified by a combination of hydrophobic interaction, ion exchange and gel filtration chromatography. These forms appear to be interconvertible. The unusual properties of the 4HBS, and its appearance in different protein fractions, raise questions as to its physiological role in vanillin biosynthesis in vivo.

  12. Unusual Thermal Hall Effect in a Kitaev Spin Liquid Candidate α -RuCl3

    Science.gov (United States)

    Kasahara, Y.; Sugii, K.; Ohnishi, T.; Shimozawa, M.; Yamashita, M.; Kurita, N.; Tanaka, H.; Nasu, J.; Motome, Y.; Shibauchi, T.; Matsuda, Y.

    2018-05-01

    The Kitaev quantum spin liquid displays the fractionalization of quantum spins into Majorana fermions. The emergent Majorana edge current is predicted to manifest itself in the form of a finite thermal Hall effect, a feature commonly discussed in topological superconductors. Here we report on thermal Hall conductivity κx y measurements in α -RuCl3 , a candidate Kitaev magnet with the two-dimensional honeycomb lattice. In a spin-liquid (Kitaev paramagnetic) state below the temperature characterized by the Kitaev interaction JK/kB˜80 K , positive κx y develops gradually upon cooling, demonstrating the presence of highly unusual itinerant excitations. Although the zero-temperature property is masked by the magnetic ordering at TN=7 K , the sign, magnitude, and T dependence of κx y/T at intermediate temperatures follows the predicted trend of the itinerant Majorana excitations.

  13. Shnirelman peak in the level spacing statistics

    International Nuclear Information System (INIS)

    Chirikov, B.V.; Shepelyanskij, D.L.

    1994-01-01

    The first results on the statistical properties of the quantum quasidegeneracy are presented. A physical interpretation of the Shnirelman theorem predicted the bulk quasidegeneracy is given. The conditions for the strong impact of the degeneracy on the quantum level statistics are formulated which allows to extend the application of the Shnirelman theorem into a broad class of quantum systems. 14 refs., 3 figs

  14. Statistical evaluation of waveform collapse reveals scale-free properties of neuronal avalanches

    Directory of Open Access Journals (Sweden)

    Aleena eShaukat

    2016-04-01

    Full Text Available Neural avalanches are a prominent form of brain activity characterized by network-wide bursts whose statistics follow a power-law distribution with a slope near 3/2. Recent work suggests that avalanches of different durations can be rescaled and thus collapsed together. This collapse mirrors work in statistical physics where it is proposed to form a signature of systems evolving in a critical state. However, no rigorous statistical test has been proposed to examine the degree to which neuronal avalanches collapse together. Here, we describe a statistical test based on functional data analysis, where raw avalanches are first smoothed with a Fourier basis, then rescaled using a time-warping function. Finally, an F ratio test combined with a bootstrap permutation is employed to determine if avalanches collapse together in a statistically reliable fashion. To illustrate this approach, we recorded avalanches from cortical cultures on multielectrode arrays as in previous work. Analyses show that avalanches of various durations can be collapsed together in a statistically robust fashion. However, a principal components analysis revealed that the offset of avalanches resulted in marked variance in the time-warping function, thus arguing for limitations to the strict fractal nature of avalanche dynamics. We compared these results with those obtained from cultures treated with an AMPA/NMDA receptor antagonist (APV/DNQX, which yield a power-law of avalanche durations with a slope greater than 3/2. When collapsed together, these avalanches showed marked misalignments both at onset and offset time-points. In sum, the proposed statistical evaluation suggests the presence of scale-free avalanche waveforms and constitutes an avenue for examining critical dynamics in neuronal systems.

  15. Unusual case of congenital/infantile fibrosarcoma in a new born

    Directory of Open Access Journals (Sweden)

    Eddiba Tarik

    2013-01-01

    Full Text Available Congenital infantile fibrosarcoma (CIFS is a rare mesenchymal tumor that is primarily developed in the soft tissue of distal extremities and occasionally in unusual locations such as the lung and retroperitoneum. It occurs mainly in children below the age of 5 years. About 200 cases have been reported in the literature so far, very few of them in new-borns. The prognosis of this tumor is relatively good compared to adult forms. We report an unusual case of CIFS occurring in new-born mimicking an hemangioma and causing hemorrhage in the neonatal period. The tumor is located in the left arm and axilla and associated with a hand malformation. A shoulder amputation is performed after chemotherapy failure. The infant is now two-years old with no recurrence.

  16. Large abdominal-pelvic cyst: An unusual presentation of hepatic echinococcosis

    Energy Technology Data Exchange (ETDEWEB)

    Borre, D.G.; Borre, G.E.

    1988-10-01

    The authors present an unusual form of hepatic echinococcosis characterized by a cystic mass that occupied the whole abdomen. The clinical features and the results of the diagnostic imaging procedures (ultrasound, computed tomography) are commented.

  17. CPT invariance and the spin-statistics connection

    CERN Document Server

    Bain, Jonathan

    2016-01-01

    This book seeks to answer the question "What explains CPT invariance and the spin-statistics connection?" These properties play foundational roles in relativistic quantum field theories (RQFTs), are supported by high-precision experiments, and figure into explanations of a wide range of phenomena, from antimatter, to the periodic table of the elements, to superconductors and superfluids. They can be derived in RQFTs by means of the famous CPT and Spin-Statistics theorems; but, the author argues, these theorems cannot be said to explain these properties, at least under standard philosophical accounts of scientific explanation. This is because there are multiple, in some cases incompatible, ways of deriving these theorems, and, secondly, because the theorems fail for the types of theories that underwrite the empirical evidence: non-relativistic quantum theories, and realistic interacting RQFTs. The goal of this book is to work towards an understanding of CPT invariance and the spin-statistics connection by firs...

  18. The effects of dynamics on statistical emission

    International Nuclear Information System (INIS)

    Friedman, W.A.

    1989-01-01

    The dynamical processes which occur during the disassembly of an excited nuclear system influence predictions arising from a statistical treatment of the decay of that system. Changes, during the decay period, in such collective properties as angular momentum, density, and kinetic energy of the emitting source affect both the mass and energy spectra of the emitted fragments. This influence will be examined. The author will explore the influence of nuclear compressibility on the decay process, in order to determine what information can be learned about this property from the products of decay. He will compare the relationship between disparate scenarios of decay: a succession of binary decays, each governed by statistics; and a full microcanonical distribution at a single freeze-out density. The author hopes to learn from the general nature of these two statistical predictions when one or the other might be more realistic, and what signatures resulting from the two models might be used to determine which accounts best for specific experimental results

  19. Chemical composition of HAL, an isotopically-unusual Allende inclusion

    Science.gov (United States)

    Davis, A. M.; Tanaka, T.; Grossman, L.; Lee, T.; Wasserburg, G. J.

    1982-01-01

    Samples of hibonite, black rim, and portions of friable rim from an unusual Allende inclusion, named HAL, were analyzed by INAA and RNAA for 37 major, minor, and trace elements. An unusually low amount of Ce was found in HAL, although it otherwise was highly enriched in REE compared to C1 chondrites. HAL is also depleted in Sr, Ba, U, V, Ru, Os, and Ir relative to other refractory elements. It is concluded that the distribution of REE between hibonite and rims was established when hibonite and other refractory minerals were removed at slightly different temperatures from a hot, oxidizing gas in which they previously coexisted as separate grains. Possible locations for the chemical and mass dependent isotopic fractionation are considered to be in ejecta from the low temperature helium-burning zone of a supernova and in the locally oxidizing environment generated by evaporation of interstellar grains of near-chondritic chemical composition.

  20. Unusual bonding and properties in main group element chemistry: rational synthesis, characterization, and experimental electron density determination of mixed-valent tetraphosphetes.

    Science.gov (United States)

    Breuers, Verena; Lehmann, Christian W; Frank, Walter

    2015-03-16

    Five dispirocyclic λ(3),λ(5)-tetraphosphetes [{R2Si(NR(1))(NR(2))P2}2] (R(1) = R(2) and R(1) ≠ R(2)) are easily prepared in almost quantitative yields via photolysis of the respective bis(trimethylsilyl)phosphanyldiazaphosphasiletidines with intense visible light. These deep-yellow low-coordinate phosphorus compounds can be considered as the first higher congeners of the well-known cyclodiphosphazenes. The tetraphosphetes are remarkably stable in air and show unexpected molecular properties related to the unique bonding situation of the central four-π-electron four-membered phosphorus ring. The extent of rhombic distortion of the central P4 ring is remarkable due to an unusually acute angle at the σ(2)-phosphorus atoms. All of the P-P bonds are approximately equal in length. The distances are in the middle of the range given by phosphorus single and double bonds. The anisotropic absorption of visible light that can easily be observed in the case of the yellow/colorless dichroic crystals of [{Me2Si(NtBu)(NtBu)P2}2] and the exceptional (31)P NMR chemical shift of the σ(2)-phosphorus atoms are the most remarkable features of the λ(3),λ(5)-tetraphosphetes. In the case of [{Me2Si(NtBu)(NtBu)P2}2], the Hansen-Coppens multipole model is applied to extract the electron density from high-resolution X-ray diffraction data obtained at 100 K. Static deformation density and topological analysis reveal a unique bonding situation in the central unsaturated P4 fragment characterized by polar σ-bonding, pronounced out-of-ring non-bonding lone pair density on the σ(2)-phosphorus atoms, and an additional non-classical three-center back-bonding contribution. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Unusual ISS Rate Signature

    Science.gov (United States)

    Laible, Michael R.

    2011-01-01

    On November 23, 2011 International Space Station Guidance, Navigation, and Control reported unusual pitch rate disturbance. These disturbances were an order of magnitude greater than nominal rates. The Loads and Dynamics team was asked to review and analyze current accelerometer data to investigate this disturbance. This paper will cover the investigation process under taken by the Loads and Dynamics group. It will detail the accelerometers used and analysis performed. The analysis included performing Frequency Fourier Transform of the data to identify the mode of interest. This frequency data is then reviewed with modal analysis of the ISS system model. Once this analysis is complete and the disturbance quantified, a forcing function was produced to replicate the disturbance. This allows the Loads and Dynamics team to report the load limit values for the 100's of interfaces on the ISS.

  2. Detection of unusual events and trends in complex non-stationary data streams

    International Nuclear Information System (INIS)

    Charlton-Perez, C.; Perez, R.B.; Protopopescu, V.; Worley, B.A.

    2011-01-01

    The search for unusual events and trends hidden in multi-component, nonlinear, non-stationary, noisy signals is extremely important for diverse applications, ranging from power plant operation to homeland security. In the context of this work, we define an unusual event as a local signal disturbance and a trend as a continuous carrier of information added to and different from the underlying baseline dynamics. The goal of this paper is to investigate the feasibility of detecting hidden events inside intermittent signal data sets corrupted by high levels of noise, by using the Hilbert-Huang empirical mode decomposition method.

  3. Applied statistical thermodynamics

    CERN Document Server

    Lucas, Klaus

    1991-01-01

    The book guides the reader from the foundations of statisti- cal thermodynamics including the theory of intermolecular forces to modern computer-aided applications in chemical en- gineering and physical chemistry. The approach is new. The foundations of quantum and statistical mechanics are presen- ted in a simple way and their applications to the prediction of fluid phase behavior of real systems are demonstrated. A particular effort is made to introduce the reader to expli- cit formulations of intermolecular interaction models and to show how these models influence the properties of fluid sy- stems. The established methods of statistical mechanics - computer simulation, perturbation theory, and numerical in- tegration - are discussed in a style appropriate for newcom- ers and are extensively applied. Numerous worked examples illustrate how practical calculations should be carried out.

  4. Statistics for experimentalists

    CERN Document Server

    Cooper, B E

    2014-01-01

    Statistics for Experimentalists aims to provide experimental scientists with a working knowledge of statistical methods and search approaches to the analysis of data. The book first elaborates on probability and continuous probability distributions. Discussions focus on properties of continuous random variables and normal variables, independence of two random variables, central moments of a continuous distribution, prediction from a normal distribution, binomial probabilities, and multiplication of probabilities and independence. The text then examines estimation and tests of significance. Topics include estimators and estimates, expected values, minimum variance linear unbiased estimators, sufficient estimators, methods of maximum likelihood and least squares, and the test of significance method. The manuscript ponders on distribution-free tests, Poisson process and counting problems, correlation and function fitting, balanced incomplete randomized block designs and the analysis of covariance, and experiment...

  5. Statistical properties of wall shear stress fluctuations in turbulent channel flows

    International Nuclear Information System (INIS)

    Keirsbulck, L.; Labraga, L.; Gad-el-Hak, M.

    2012-01-01

    Highlights: ► Accurate measurements of instantaneous wall shear stress are conducted. ► LDA is used to measure near-wall streamwise velocity. ► Electrochemical probe is used to measure wall shear stress. ► Frequency response and non-uniform correction methods were used to provide an accurate, well-resolved wall-statistics database. ► Reynolds number dependency of the statistical wall quantities is investigated. - Abstract: Instantaneous velocity and wall shear stress measurements are conducted in a turbulent channel flow in the Kármán number range of Re τ = 74–400. A one-dimensional LDA system is used to measure the streamwise velocity fluctuations, and an electrochemical technique is utilized to measure the instantaneous wall shear stress. For the latter, frequency response and nonuniform correction methods are used to provide an accurate, well-resolved wall statistics database. The Reynolds number dependency of the statistical wall quantities is carefully investigated. The corrected relative wall shear stress fluctuations fit well with the best DNS data available and meet the need for clarification of the small discrepancy observed in the literature between the experimental and numerical results of such quantities. Higher-order statistics of the wall shear stress, spectra, and the turbulence kinetic energy budget at the wall are also investigated. The present paper shows that the electrochemical technique is a powerful experimental method for hydrodynamic studies involving highly unsteady flows. The study brings with it important consequences, especially in the context of the current debate regarding the appropriate scaling as well as the validation of new predictive models of near-wall turbulence.

  6. A Case of Unusual Clitoromegaly.

    Science.gov (United States)

    Wooi Ch'ng, Tong; Umpaichitra, Vatcharapan

    2018-05-03

    Mild degree of clitoromegaly can be associated with patient with polycystic ovarian syndrome (PCOS). We describe an unusually significant clitoromegaly in a patient with PCOS. An 18-year old non-obese female referred for clitoromegaly. Her genitalia exam showed significant clitoral enlargement with a well-formed glans, clitoris measured at 35 mm for length and 10 mm for width. Pelvic ultrasound showed left ovarian cyst. Testosterone level ranged from 28.8 to 64.1 ng/dl (normal: 8.4-48.1 ng/dl) with normal sex hormone binding globulin. Other ovarian hormones were in acceptable ranges. This case demonstrates the coexistence of significant clitoromegaly, PCOS, and non-functioning ovarian cyst. Copyright © 2018. Published by Elsevier Inc.

  7. Ruptured rectal duplication with urogenital abnormality: Unusual presentation

    Directory of Open Access Journals (Sweden)

    Shailesh Solanki

    2015-01-01

    Full Text Available Rectal duplication (RD accounts for 5% of alimentary tract duplication. A varied presentation and associated anomalies have been described in the literature. Antenatal rupture of the RD is very rare. We present an unusual case of a ruptured RD associated with urogenital abnormalities in newborn male. We are discussing diagnosis, embryology, management and literature review of ruptured RD.

  8. A primer of statistical methods for correlating parameters and properties of electrospun poly(l -lactide) scaffolds for tissue engineering-PART 1: Design of experiments

    KAUST Repository

    Seyedmahmoud, Rasoul

    2014-03-20

    Tissue engineering scaffolds produced by electrospinning are of enormous interest, but still lack a true understanding about the fundamental connection between the outstanding functional properties, the architecture, the mechanical properties, and the process parameters. Fragmentary results from several parametric studies only render some partial insights that are hard to compare and generally miss the role of parameters interactions. To bridge this gap, this article (Part-1 of 2) features a case study on poly-l-lactide scaffolds to demonstrate how statistical methods such as design of experiments can quantitatively identify the correlations existing between key scaffold properties and control parameters, in a systematic, consistent, and comprehensive manner disentangling main effects from interactions. The morphological properties (i.e., fiber distribution and porosity) and mechanical properties (Young\\'s modulus) are "charted" as a function of molecular weight (MW) and other electrospinning process parameters (the Xs), considering the single effect as well as interactions between Xs. For the first time, the major role of the MW emerges clearly in controlling all scaffold properties. The correlation between mechanical and morphological properties is also addressed.

  9. Identifying sources of soil inorganic pollutants on a regional scale using a multivariate statistical approach: Role of pollutant migration and soil physicochemical properties

    International Nuclear Information System (INIS)

    Zhang Changbo; Wu Longhua; Luo Yongming; Zhang Haibo; Christie, Peter

    2008-01-01

    Principal components analysis (PCA) and correlation analysis were used to estimate the contribution of four components related to pollutant sources on the total variation in concentrations of Cu, Zn, Pb, Cd, As, Se, Hg, Fe and Mn in surface soil samples from a valley in east China with numerous copper and zinc smelters. Results indicate that when carrying out source identification of inorganic pollutants their tendency to migrate in soils may result in differences between the pollutant composition of the source and the receptor soil, potentially leading to errors in the characterization of pollutants using multivariate statistics. The stability and potential migration or movement of pollutants in soils must therefore be taken into account. Soil physicochemical properties may offer additional useful information. Two different mechanisms have been hypothesized for correlations between soil heavy metal concentrations and soil organic matter content and these may be helpful in interpreting the statistical analysis. - Principal components analysis with Varimax rotation can help identify sources of soil inorganic pollutants but pollutant migration and soil properties can exert important effects

  10. Unusual causes of acute abdomen in a Nigerian hospital ...

    African Journals Online (AJOL)

    Acute abdomen is the most common abdominal emergency associated with high morbidity and mortality in General surgical practice. Over a 7-year period, a study of unusual causes of acute abdomen was undertaken, with the aim of identifying these causes and outcome of operative management. Eleven cases were ...

  11. The insignificance of statistical significance testing

    Science.gov (United States)

    Johnson, Douglas H.

    1999-01-01

    Despite their use in scientific journals such as The Journal of Wildlife Management, statistical hypothesis tests add very little value to the products of research. Indeed, they frequently confuse the interpretation of data. This paper describes how statistical hypothesis tests are often viewed, and then contrasts that interpretation with the correct one. I discuss the arbitrariness of P-values, conclusions that the null hypothesis is true, power analysis, and distinctions between statistical and biological significance. Statistical hypothesis testing, in which the null hypothesis about the properties of a population is almost always known a priori to be false, is contrasted with scientific hypothesis testing, which examines a credible null hypothesis about phenomena in nature. More meaningful alternatives are briefly outlined, including estimation and confidence intervals for determining the importance of factors, decision theory for guiding actions in the face of uncertainty, and Bayesian approaches to hypothesis testing and other statistical practices.

  12. Origami-based cellular metamaterial with auxetic, bistable, and self-locking properties

    Science.gov (United States)

    Kamrava, Soroush; Mousanezhad, Davood; Ebrahimi, Hamid; Ghosh, Ranajay; Vaziri, Ashkan

    2017-04-01

    We present a novel cellular metamaterial constructed from Origami building blocks based on Miura-ori fold. The proposed cellular metamaterial exhibits unusual properties some of which stemming from the inherent properties of its Origami building blocks, and others manifesting due to its unique geometrical construction and architecture. These properties include foldability with two fully-folded configurations, auxeticity (i.e., negative Poisson’s ratio), bistability, and self-locking of Origami building blocks to construct load-bearing cellular metamaterials. The kinematics and force response of the cellular metamaterial during folding were studied to investigate the underlying mechanisms resulting in its unique properties using analytical modeling and experiments.

  13. An Unusual Laryngeal Foreign Body in Adult.

    Science.gov (United States)

    Ndiaye, Cire; Regonne, Eric Joel; Ahmed, Houra; Diom, Evelyne Siga; Deguenonvo, Richard Edouard Alain; Mbaye, Aminata; Zemene, Yilkal; Ndiaye, Issa Cheikh

    2016-01-01

    The accidental aspiration of a foreign body is a frequent domestic accident among children but a rare occurrence in adults. The laryngeal impaction of a coin is an unusual accident; only a few cases have been reported in the literature. Diagnosis is mostly achieved by clinicoradiological examinations. The authors report an uncommon case of laryngeal impaction of a coin in a 21-year-old patient, presenting with dysphonia without dyspnea or stridor. The extraction was performed by endoscopy.

  14. An Unusual Laryngeal Foreign Body in Adult

    OpenAIRE

    Ndiaye, Cire; Regonne, Eric Joel; Ahmed, Houra; Diom, Evelyne Siga; Deguenonvo, Richard Edouard Alain; Mbaye, Aminata; Zemene, Yilkal; Ndiaye, Issa Cheikh

    2016-01-01

    The accidental aspiration of a foreign body is a frequent domestic accident among children but a rare occurrence in adults. The laryngeal impaction of a coin is an unusual accident; only a few cases have been reported in the literature. Diagnosis is mostly achieved by clinicoradiological examinations. The authors report an uncommon case of laryngeal impaction of a coin in a 21-year-old patient, presenting with dysphonia without dyspnea or stridor. The extraction was performed by endoscopy.

  15. Structure, reactivity and electronic properties of Mn doped Ni13 clusters

    International Nuclear Information System (INIS)

    Banerjee, Radhashyam; Datta, Soumendu; Mookerjee, Abhijit

    2013-01-01

    In this work we have studied the structural and magnetic properties of Ni 13 cluster mono- and bi-doped with Mn atoms. We have noted their tendency of being reactive toward the H 2 molecule. We have found unusually enhanced stability in the mono-doped cluster (i.e. of the Ni 12 Mn) and the diminished stability of the corresponding chemisorbed cluster, Ni 12 MnH 2 . Our analysis of the stability and HOMO–LUMO gap explains this unusual behavior. Interestingly, we have also seen the quenching in the net magnetic moment upon H 2 absorption in the doped Ni 13−m Mn m alloy clusters. This has been reported earlier for smaller Ni n clusters [1

  16. Structure, reactivity and electronic properties of Mn doped Ni13 clusters

    Science.gov (United States)

    Banerjee, Radhashyam; Datta, Soumendu; Mookerjee, Abhijit

    2013-06-01

    In this work we have studied the structural and magnetic properties of Ni13 cluster mono- and bi-doped with Mn atoms. We have noted their tendency of being reactive toward the H2 molecule. We have found unusually enhanced stability in the mono-doped cluster (i.e. of the Ni12Mn) and the diminished stability of the corresponding chemisorbed cluster, Ni12MnH2. Our analysis of the stability and HOMO-LUMO gap explains this unusual behavior. Interestingly, we have also seen the quenching in the net magnetic moment upon H2 absorption in the doped NiMnm alloy clusters. This has been reported earlier for smaller Nin clusters [1].

  17. Thermodynamics for Fractal Statistics

    OpenAIRE

    da Cruz, Wellington

    1998-01-01

    We consider for an anyon gas its termodynamics properties taking into account the fractal statistics obtained by us recently. This approach describes the anyonic excitations in terms of equivalence classes labeled by fractal parameter or Hausdorff dimension $h$. An exact equation of state is obtained in the high-temperature and low-temperature limits, for gases with a constant density of states.

  18. Electronic and magnetic properties of ultrathin rhodium nanowires

    CERN Document Server

    Wang Bao Lin; Ren-Yun; Sun Hou Qian; Chen Xiao Shuang; Zhao Ji Jun

    2003-01-01

    The structures of ultrathin rhodium nanowires are studied using empirical molecular dynamics simulations with a genetic algorithm. Helical multishell cylindrical and pentagonal packing structures are found. The electronic and magnetic properties of the rhodium nanowires are calculated using an spd tight-binding Hamiltonian in the unrestricted Hartree-Fock approximation. The average magnetic moment and electronic density of states are obtained. Our results indicate that the electronic and magnetic properties of the rhodium nanowires depend not only on the size of the wire but also on the atomic structure. In particular, centred pentagonal and hexagonal structures can be unusually ferromagnetic.

  19. Case series of unusual causes intestinal obstruction in infants and ...

    African Journals Online (AJOL)

    Introduction Many of the causes of intestinal obstruction arise from ... In this work, we report eight unusual cases of intestinal ..... lymph is considered to be the result of an imbalance ... During fetal life, midgut communicates with the yolk sac.

  20. Oral malignant melanoma: a rare case with unusual clinical ...

    African Journals Online (AJOL)

    Primary Oral malignant melanoma is a rare tumor with an indigent prognosis. This is a case report of 47-year-old Sudanese female diagnosed as Oral malignant melanoma of the mandible with an unusual pattern of growth and clinical presentation. Furthermore, a possibility of intraosseous origin is suggested. Pan African ...

  1. Humidity Effects on Soluble Core Mechanical and Thermal Properties (Polyvinyl Alcohol/Microballoon Composite)

    Science.gov (United States)

    1993-01-01

    This document constitutes the final report for the study of humidity effects and loading rate on soluble core (PVA/MB composite material) mechanical and thermal properties. This report describes test results, procedures employed, and any unusual occurrences or specific observations associated with this test program.

  2. Cardiopulmonary Resuscitation: Unusual Techniques for Unusual Situations

    Directory of Open Access Journals (Sweden)

    Vidhu Bhatnagar

    2018-01-01

    Full Text Available Background: The cardiopulmonary resuscitation (CPR in prone position has been dealt with in 2010 American Heart Association (AHA guidelines but have not been reviewed in 2015 guidelines. The guidelines for patients presenting with cardiac arrest under general anesthesia in lateral decubitus position and regarding resuscitation in confined spaces like airplanes are also not available in AHA guidelines. This article is an attempt to highlight the techniques adopted for resuscitation in these unusual situations. Aims: This study aims to find out the methodology and efficacy in nonconventional CPR approaches such as CPR in prone, CPR in lateral position, and CPR in confined spaces. Methods: We conducted a literature search using MeSH search strings such as CPR + Prone position, CPR + lateral Position, and CPR + confined spaces. Results: No randomized controlled trials are available. The literature search gives a handful of case reports, some simulation- and manikin-based studies but none can qualify for class I evidence. The successful outcome of CPR performed in prone position has shown compressions delivered on the thoracic spine with the same rate and force as they were delivered during supine position. A hard surface is required under the patient to provide uniform force and sternal counter pressure. Two rescuer technique for providing successful chest compression in lateral position has been documented in the few case reports published. Over the head CPR and straddle (STR, CPR has been utilized for CPR in confined spaces. Ventilation in operating rooms was taken care by an advanced airway in situ. Conclusion: A large number of studies of high quality are required to be conducted to determine the efficacy of CPR in such positions.

  3. Statistical properties of aerosol-cloud-precipitation interactions in South America

    Directory of Open Access Journals (Sweden)

    T. A. Jones

    2010-03-01

    Full Text Available Given the complex interaction between aerosol, cloud, and atmospheric properties, it is difficult to extract their individual effects to observed rainfall amount. This research uses principle component analysis (PCA that combines Moderate Resolution Imaging Spectroradiometer (MODIS aerosol and cloud products, NCEP Reanalysis atmospheric products, and rainrate estimates from the Tropical Rainfall Measuring Mission (TRMM precipitation radar (PR to assess if aerosols affect warm rain processes. Data collected during September 2006 over the Amazon basin in South America during the biomass-burning season are used. The goal of this research is to combine these observations into a smaller number of variables through PCA with each new variable having a unique physical interpretation. In particular, we are concerned with PC variables whose weightings include aerosol optical thickness (AOT, as these may be an indicator of aerosol indirect effects. If they are indeed occurring, then PC values that include AOT should change as a function of rainrate.

    To emphasize the advantage of PCA, changes in aerosol, cloud, and atmospheric observations are compared to rainrate. Comparing no-rain, rain, and heavy rain only (>5 mm h−1 samples, we find that cloud thicknesses, humidity, and upward motion are all greater during rain and heavy rain conditions. However, no statistically significant difference in AOT exists between each sample, indicating that atmospheric conditions are more important to rainfall than aerosol concentrations as expected. If aerosols are affecting warm process clouds, it would be expected that stratiform precipitation would decrease as a function increasing aerosol concentration through either Twomey and/or semi-direct effects. PCA extracts the latter signal in a variable labeled PC2, which explains 15% of the total variance and is second in importance the variable (PC1 containing the broad atmospheric conditions. PC2

  4. Unusual Cases of Hypothenar Hammer Syndrome.

    Science.gov (United States)

    Orrapin, Saranat; Arworn, Supapong; Wisetborisut, Anawat

    2015-01-01

    Hypothenar hammer syndrome (HHS) is a rare occupational disease. The risk group of HHS is patient whose dominate hand used as a hammer. Our study report unusually cases in Chiang Mai University Hospital. 19 year-old basketball player had right ulnar artery aneurysm for two months. After operation, his symptom was relieved and returned to play basketball again. 65 year-old housekeeper had non-dominated hand ulnar artery aneurysm for two years. After operation she still had hand claudication due to poor run-off vessel. HHS is previously state in risk group. But from our report there was a risk in different occupation.

  5. An Unusual Case of Gastrointestinal Bleeding

    Directory of Open Access Journals (Sweden)

    Kristin N. Fiorino

    2011-01-01

    Full Text Available A 10-year-old boy presented with a 3-day history of worsening abdominal pain, fever, emesis and melena. Abdominal ultrasound revealed a right upper quadrant mass that was confirmed by computed tomography angiogram (CTA, which showed an 8 cm well-defined retroperitoneal vascular mass. 123Iodine metaiodobenzylguanidine (123MIBG scan indicated uptake only in the abdominal mass. Subsequent biopsy revealed a paraganglioma that was treated with chemotherapy. This case represents an unusual presentation of a paraganglioma associated with gastrointestinal (GI bleeding and highlights the utility of CTA and 123MIBG in evaluation and treatment.

  6. An unusually strong Einstein ring in the radio source PKS1830-211

    International Nuclear Information System (INIS)

    Jauncey, D.L.

    1991-01-01

    RADIO observations of the strong, flat-spectrum radio source PKS1830-211 revealed a double structure, with a separation of 1 arcsec, suggesting that it might be a gravitationally lensed object. We have now obtained high-resolution radio images of PKS1830-211 from several interferometric radiotelescope networks, which show an unusual elliptical ring-like structure connecting the two brighter components. The presence of the ring, and the similarity of the two brighter spots, argue strongly that this is indeed a gravitationally lensed system, specifically an Einstein ring in which lens and lensed object are closely aligned. Although the source is close to the galactic plane, it seems that both the lens and background (lensed) object are extragalactic. This object is one hundred times brighter than either of the two previously discovered radio Einstein rings, and is among the six brightest flat-spectrum sources in the sky. Its brightness makes it a peculiar object: it must involve either a chance alignment of a lensing object with an unusually bright background source, or an alignment with a less bright object but amplified to an unusual degree. (author)

  7. Statistical mechanics of black holes

    International Nuclear Information System (INIS)

    Harms, B.; Leblanc, Y.

    1992-01-01

    We analyze the statistical mechanics of a gas of neutral and charged black holes. The microcanonical ensemble is the only possible approach to this system, and the equilibrium configuration is the one for which most of the energy is carried by a single black hole. Schwarzschild black holes are found to obey the statistical bootstrap condition. In all cases, the microcanonical temperature is identical to the Hawking temperature of the most massive black hole in the gas. U(1) charges in general break the bootstrap property. The problems of black-hole decay and of quantum coherence are also addressed

  8. Energy-level statistics and time relaxation in quantum systems

    International Nuclear Information System (INIS)

    Gruver, J.L.; Cerdeira, H.A.; Aliaga, J.; Mello, P.A.; Proto, A.N.

    1997-05-01

    We study a quantum-mechanical system, prepared, at t = 0, in a model state, that subsequently decays into a sea of other states whose energy levels form a discrete spectrum with given statistical properties. An important quantity is the survival probability P(t), defined as the probability, at time t, to find the system in the original model state. Our main purpose is to analyze the influence of the discreteness and statistical properties of the spectrum on the behavior of P(t). Since P(t) itself is a statistical quantity, we restrict our attention to its ensemble average , which is calculated analytically using random-matrix techniques, within certain approximations discussed in the text. We find, for , an exponential decay, followed by a revival, governed by the two-point structure of the statistical spectrum, thus giving a nonzero asymptotic value for large t's. The analytic result compares well with a number of computer simulations, over a time range discussed in the text. (author). 17 refs, 1 fig

  9. Compound speckles and their statistical and dynamical properties

    DEFF Research Database (Denmark)

    Hanson, Steen Grüner; Jakobsen, Michael Linde; Skov Hansen, Rene

    2008-01-01

    Two issues will be treated in this presentation, both focusing on gaining a deeper understanding of dynamic speckles, aiming at the use for probing dynamical properties of scattering structures. The first issue to be addressed is the dynamics of speckles arising from illuminating a solid surface...

  10. Transparent control of three-body selective destruction of tunneling via unusual states

    International Nuclear Information System (INIS)

    Luo, Yunrong; Tan, Jintao; Hai, Wenhua; Lu, Gengbiao

    2015-01-01

    We study transparent control of quantum tunneling via unusual analytical solutions for three bosons held in a driven double-well. Under high-frequency approximation, we analytically obtain the fine band structure and general non-Floquet state. At some collapse points of the quasi-energy spectra, the latter becomes the unusual special states. Based on the analytical results and their numerical correspondences, we clearly reveal the mechanism of coherent tunneling and suggest a scheme to transparently control the tunneling of three bosons from one well to another. The results can be observed with the current experimental capability (Chen et al 2011 Phys. Rev. Lett. 107 210405) (paper)

  11. Statistical Model Checking for Biological Systems

    DEFF Research Database (Denmark)

    David, Alexandre; Larsen, Kim Guldstrand; Legay, Axel

    2014-01-01

    Statistical Model Checking (SMC) is a highly scalable simulation-based verification approach for testing and estimating the probability that a stochastic system satisfies a given linear temporal property. The technique has been applied to (discrete and continuous time) Markov chains, stochastic...

  12. Unusual migration of ventriculo peritoneal distal catheter into vagina

    Directory of Open Access Journals (Sweden)

    Sghavamedin Tavallaee

    2015-04-01

    Full Text Available VP shunt is one of the most popular methods for ICP reduction and treatment of hydrocephalus. Various complications of this method are not uncommon such as shunt malfunction, infection and unusual migration of distal catheter. I present a case of migration of the peritoneal catheter out of the vagina.

  13. Large Penile Mass With Unusual Benign Histopathology

    Directory of Open Access Journals (Sweden)

    Nate Johnson

    2015-09-01

    Full Text Available Pseudoepitheliomatous hyperplasia is an extremely rare condition presenting as a lesion on the glans penis in older men. Physical exam without biopsy cannot differentiate malignant from nonmalignant growth. We report a case of large penile mass in an elderly male with a history of lichen sclerosis, highly suspicious for malignancy. Subsequent surgical removal and biopsy demonstrated pseudoepitheliomatous hyperplasia, an unusual benign histopathologic diagnosis with unclear prognosis. We review the literature and discuss options for treatment and surveillance.

  14. An Unusual Laryngeal Foreign Body in Adult

    Directory of Open Access Journals (Sweden)

    Cire Ndiaye

    2016-01-01

    Full Text Available The accidental aspiration of a foreign body is a frequent domestic accident among children but a rare occurrence in adults. The laryngeal impaction of a coin is an unusual accident; only a few cases have been reported in the literature. Diagnosis is mostly achieved by clinicoradiological examinations. The authors report an uncommon case of laryngeal impaction of a coin in a 21-year-old patient, presenting with dysphonia without dyspnea or stridor. The extraction was performed by endoscopy.

  15. Quantum statistics of many-particle systems

    International Nuclear Information System (INIS)

    Kraeft, W.D.; Ebeling, W.; Kremp, D.; Ropke, G.

    1986-01-01

    This paper presents the elements of quantum statistics and discusses the quantum mechanics of many-particle systems. The method of second quantization is discussed and the Bogolyubov hierarchy is examined. The general properties of the correlation function and one-particle Green's function are examined. The paper presents dynamical and thermodynamical information contained in the spectral function. An equation of motion is given for the one-particle Green's function. T-matrix and thermodynamic properties in binary collision approximation are discussed

  16. Understanding the Unusual 2017 Monsoon and Floods in South Asia

    Science.gov (United States)

    Akanda, A. S.; Palash, W.; Hasan, M. A.; Nusrat, F.

    2017-12-01

    Driven primarily by the South Asian Monsoon, the Ganges-Brahmaputra-Meghna (GBM) river basin system collectively drains intense precipitation for an area of more than 1.5 million square kilometers during the wet summer season. Bangladesh, being the lowest riparian country in the system, experiences recurrent floods and immense suffering to its population. The 2017 monsoon season was quite unusual in terms of the characteristics of the precipitation received in the basin. The monsoon was spread out over a much larger time span (April-October) compared to the average monsoon season (June-September). Although the monsoon does not typically start until June in Bangladesh, the 2017 season started much earlier in April with unusually heavy precipitation in the Meghna basin region and caused major damage to agriculture in northeastern Bangladesh. The rainfall continued in several record-breaking pulses, compared to the typical one or two large waves. One of the largest pulses occurred in early August with very high in intensity and volume, causing ECMWF to issue a major warning about widespread flooding in Bangladesh, Northern India, and Eastern Nepal. This record flood event impacted over 40 million people in the above regions, causing major damage to life and infrastructure. Although the Brahmaputra rose above the danger level several times this season, the Ganges was unusually low, thus sparing downstream areas from disastrous floods. However, heavy precipitation continued until October, causing urban flooding in Dhaka and Chittagong - and worsening sanitation and public health conditions in southern Bangladesh - currently undergoing a terrible humanitarian crisis involving Rohingya refugees from the Myanmar. Despite marked improvement in flood forecasting systems in recent years, the 2017 floods identified critical gaps in our understanding of the flooding phenomena and limitations of dissemination in these regions. In this study, we investigate 1) the unusual

  17. Vaginal haemangioendothelioma: an unusual tumour.

    LENUS (Irish Health Repository)

    Mohan, H

    2012-02-01

    Vaginal tumours are uncommon and this is a particularly rare case of a vaginal haemangioendothelioma in a 38-year-old woman. Initial presentation consisted of symptoms similar to uterovaginal prolapse with "something coming down". Examination under anaesthesia demonstrated a necrotic anterior vaginal wall tumour. Histology of the lesion revealed a haemangioendothelioma which had some features of haemangiopericytoma. While the natural history of vaginal haemangioendothelioma is uncertain, as a group, they have a propensity for local recurrence. To our knowledge this is the third reported case of a vaginal haemangioendothelioma. Management of this tumour is challenging given the paucity of literature on this tumour. There is a need to add rare tumours to our "knowledge bank" to guide management of these unusual tumours.

  18. Unusual clinical manifestations of leptospirosis

    Directory of Open Access Journals (Sweden)

    Bal A

    2005-01-01

    Full Text Available Leptospirosis has protean clinical manifestations. The classical presentation of the disease is an acute biphasic febrile illness with or without jaundice. Unusual clinical manifestations may result from involvement of pulmonary, cardiovascular, neural, gastrointestinal, ocular and other systems. Immunological phenomena secondary to antigenic mimicry may also be an important component of many clinical features and may be responsible for reactive arthritis. Leptospirosis in early pregnancy may lead to fetal loss. There are a few reports of leptospirosis in HIV- infected individuals but no generalisation can be made due to paucity of data. It is important to bear in mind that leptospiral illness may be a significant component in cases of dual infections or in simultaneous infections with more than two pathogens.

  19. Scientific Letter: Stabbing nails into the neck: an unusual self ...

    African Journals Online (AJOL)

    Scientific Letter: Stabbing nails into the neck: an unusual self-damaging behavior mandating neurosurgery. A Aghabiklooei, R Aghabiklooei, N Zamani. Abstract. Scientific Letter - No Abstract Available. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT.

  20. Origin of an unusual heavy oil from the Baiyinchagan depression, Erlian basin, northern China

    Energy Technology Data Exchange (ETDEWEB)

    Haiping Huang [China University of Geosciences, Beijing (China); University of Newcastle, Newcastle upon Tyne (United Kingdom). School of Civil Engineering and Geosciences; Guangxi Jin [China University of Geosciences, Beijing (China); Exploration and Development Institute, Puyang (China); Changsong Lin; Yabin Zheng [China University of Geosciences, Beijing (China)

    2003-01-01

    A detailed organic geochemical analysis of six oil samples from the Baiyinchagan depression in the Erlian basin, Northern China, was carried out in order to evaluate their origin. The oils are reservoired at a very shallow depth (223-560 m subsurface) and their chemical and physical properties vary greatly, ranging from normal to extremely heavy oil. The preservation of non-biodegraded oil in such a shallow reservoir is possibly related with palaeo-pasteurization of the reservoir before uplift. Maturity difference is not the primary control on the chemical and physical properties of the oils and there is considerable geochemical evidence to suggest the additional influence of in-reservoir/post-accumulation processes such as biodegradation, water-washing and (possibly) evaporation. Whereas some oils appear to be less affected, others are moderately biodegraded up to level 4 on the [Peters and Moldowan, 1993] scale, with sterane distributions largely unaffected and 25-norhopanes undetected. Contrary to classical biodegradation, the unusual heavy oil shows little evidence of biodegradation from aliphatic components. Water-washing is suggested to be the primary process leading to its formation since the severe alteration of soluble aromatic hydrocarbons is observed. In addition, since the oils have been uplifted significantly after accumulation, evaporation and/or leakage to modify oil compositions cannot be ruled out. (author)

  1. Ontologies and tag-statistics

    Science.gov (United States)

    Tibély, Gergely; Pollner, Péter; Vicsek, Tamás; Palla, Gergely

    2012-05-01

    reproducing the main statistical features of tag co-occurrence. This model has high potential for further practical applications, e.g., it can provide the starting point for a benchmark system in ontology retrieval or it may help pinpoint unusual correlations in the co-occurrence of tags.

  2. Ontologies and tag-statistics

    International Nuclear Information System (INIS)

    Tibély, Gergely; Vicsek, Tamás; Pollner, Péter; Palla, Gergely

    2012-01-01

    reproducing the main statistical features of tag co-occurrence. This model has high potential for further practical applications, e.g., it can provide the starting point for a benchmark system in ontology retrieval or it may help pinpoint unusual correlations in the co-occurrence of tags. (paper)

  3. Statistical properties of random clique networks

    Science.gov (United States)

    Ding, Yi-Min; Meng, Jun; Fan, Jing-Fang; Ye, Fang-Fu; Chen, Xiao-Song

    2017-10-01

    In this paper, a random clique network model to mimic the large clustering coefficient and the modular structure that exist in many real complex networks, such as social networks, artificial networks, and protein interaction networks, is introduced by combining the random selection rule of the Erdös and Rényi (ER) model and the concept of cliques. We find that random clique networks having a small average degree differ from the ER network in that they have a large clustering coefficient and a power law clustering spectrum, while networks having a high average degree have similar properties as the ER model. In addition, we find that the relation between the clustering coefficient and the average degree shows a non-monotonic behavior and that the degree distributions can be fit by multiple Poisson curves; we explain the origin of such novel behaviors and degree distributions.

  4. Statistical eclipses of close-in Kepler sub-Saturns

    Energy Technology Data Exchange (ETDEWEB)

    Sheets, Holly A.; Deming, Drake, E-mail: hsheets@astro.umd.edu [Department of Astronomy, University of Maryland, College Park, MD 20742-2421 (United States)

    2014-10-20

    We present a method to detect small atmospheric signals in Kepler's planet candidate light curves by averaging light curves for multiple candidates with similar orbital and physical characteristics. Our statistical method allows us to measure unbiased physical properties of Kepler's planet candidates, even for candidates whose individual signal-to-noise precludes the detection of their secondary eclipse. We detect a secondary eclipse depth of 3.83{sub −1.11}{sup +1.10} ppm for a group of 31 sub-Saturn (R < 6 R {sub ⊕}) planet candidates with the greatest potential for a reflected light signature ((R{sub p} /a){sup 2} > 10 ppm). Including Kepler-10b in this group increases the depth to 5.08{sub −0.72}{sup +0.71} ppm. For a control group with (R{sub p} /a){sup 2} < 1 ppm, we find a depth of 0.36 ± 0.37 ppm, consistent with no detection. We also analyze the light curve of Kepler-10b and find an eclipse depth of 7.08 ± 1.06 ppm. If the eclipses are due solely to reflected light, this corresponds to a geometric albedo of 0.22 ± 0.06 for our group of close-in sub-Saturns, 0.37 ± 0.05 if including Kepler-10b in the group, and 0.60 ± 0.09 for Kepler-10b alone. Including a thermal emission model does not change the geometric albedo appreciably, assuming A{sub B} = (3/2)*A{sub g} . Our result for Kepler-10b is consistent with previous works. Our result for close-in sub-Saturns shows that Kepler-10b is unusually reflective, but our analysis is consistent with the results of Demory for super-Earths. Our results also indicate that hot Neptunes are typically more reflective than hot Jupiters.

  5. Embolia cutis medicamentosa: an unusual adverse reaction to terlipressin

    Science.gov (United States)

    Gatos-Gatopoulos, Polychronis; Kostantoudakis, Stephanos; Panayiotides, Ioannis G.; Dimitriadis, George D.; Triantafyllou, Konstantinos

    2017-01-01

    Terlipressin is a synthetic long-acting analog of vasopressin widely used to control variceal bleeding by lowering portal venous pressure. We report an unusual adverse reaction to terlipressin in a 78-year-old patient with esophageal variceal bleeding who developed skin necrosis soon after treatment initiation. Skin biopsy revealed embolia cutis medicamentosa. PMID:29118569

  6. Neck mass: An unusual presentation of prostate cancer metastasis ...

    African Journals Online (AJOL)

    Globally, prostate cancer is a disease of public health importance and it is most common among men between 60 to 70 years of age. Distant primaries involving supraclavicular nodes secondary to prostate cancer is very rare. This report is a case of an unusual presentation of prostate cancer manifesting as a huge neck ...

  7. Open-chain poly(organophosphazenes). Synthesis and properties

    International Nuclear Information System (INIS)

    Vinogradova, Svetlana V; Tur, Dzidra R; Vasnev, Valery A

    1998-01-01

    Various methods for the synthesis of open-chain poly(organophosphazenes) are considered. The mechanism of polymerisation of hexachlorocyclotriphosphazene and the basic principles of formation of poly(organophosphazene) macromolecules by polymeranalogous reactions of poly(dichloro-phosphazene) with various nucleophilic reagents are analysed from a new viewpoint. The potential of this synthetic method for targeted design of poly(organophosphazenes) of various structures is shown. The possibility of synthesising poly(organophosphazenes) by polymerisation of cyclophosphazenes is also discussed. The problem of unit non-uniformity of poly(organophosphazenes) and its influence on the properties of these polymers are considered. The properties of poly(organophosphazenes) are considered in detail and it is shown that these polymers possess unusual valuable properties, which provide opportunities for their successful practical application. The bibliography includes 276 references.

  8. Statistical retrieval of thin liquid cloud microphysical properties using ground-based infrared and microwave observations

    Science.gov (United States)

    Marke, Tobias; Ebell, Kerstin; Löhnert, Ulrich; Turner, David D.

    2016-12-01

    In this article, liquid water cloud microphysical properties are retrieved by a combination of microwave and infrared ground-based observations. Clouds containing liquid water are frequently occurring in most climate regimes and play a significant role in terms of interaction with radiation. Small perturbations in the amount of liquid water contained in the cloud can cause large variations in the radiative fluxes. This effect is enhanced for thin clouds (liquid water path, LWP cloud properties crucial. Due to large relative errors in retrieving low LWP values from observations in the microwave domain and a high sensitivity for infrared methods when the LWP is low, a synergistic retrieval based on a neural network approach is built to estimate both LWP and cloud effective radius (reff). These statistical retrievals can be applied without high computational demand but imply constraints like prior information on cloud phase and cloud layering. The neural network retrievals are able to retrieve LWP and reff for thin clouds with a mean relative error of 9% and 17%, respectively. This is demonstrated using synthetic observations of a microwave radiometer (MWR) and a spectrally highly resolved infrared interferometer. The accuracy and robustness of the synergistic retrievals is confirmed by a low bias in a radiative closure study for the downwelling shortwave flux, even for marginally invalid scenes. Also, broadband infrared radiance observations, in combination with the MWR, have the potential to retrieve LWP with a higher accuracy than a MWR-only retrieval.

  9. Statistical properties of SASE FEL radiation: experimental results from the VUV FEL at the TESLA test facility at DESY

    International Nuclear Information System (INIS)

    Yurkov, M.V.

    2002-01-01

    This paper presents an experimental study of the statistical properties of the radiation from a SASE FEL. The experiments were performed at the TESLA Test Facility VUV SASE FEL at DESY operating in a high-gain linear regime with a gain of about 10 6 . It is shown that fluctuations of the output radiation energy follows a gamma-distribution. We also measured for the first time the probability distribution of SASE radiation energy after a narrow-band monochromator. The experimental results are in good agreement with theoretical predictions, the energy fluctuations after the monochromator follow a negative exponential distribution

  10. A primer of statistical methods for correlating parameters and properties of electrospun poly(L-lactide) scaffolds for tissue engineering--PART 1: design of experiments.

    Science.gov (United States)

    Seyedmahmoud, Rasoul; Rainer, Alberto; Mozetic, Pamela; Maria Giannitelli, Sara; Trombetta, Marcella; Traversa, Enrico; Licoccia, Silvia; Rinaldi, Antonio

    2015-01-01

    Tissue engineering scaffolds produced by electrospinning are of enormous interest, but still lack a true understanding about the fundamental connection between the outstanding functional properties, the architecture, the mechanical properties, and the process parameters. Fragmentary results from several parametric studies only render some partial insights that are hard to compare and generally miss the role of parameters interactions. To bridge this gap, this article (Part-1 of 2) features a case study on poly-L-lactide scaffolds to demonstrate how statistical methods such as design of experiments can quantitatively identify the correlations existing between key scaffold properties and control parameters, in a systematic, consistent, and comprehensive manner disentangling main effects from interactions. The morphological properties (i.e., fiber distribution and porosity) and mechanical properties (Young's modulus) are "charted" as a function of molecular weight (MW) and other electrospinning process parameters (the Xs), considering the single effect as well as interactions between Xs. For the first time, the major role of the MW emerges clearly in controlling all scaffold properties. The correlation between mechanical and morphological properties is also addressed. © 2014 Wiley Periodicals, Inc.

  11. Mean-field theory of anyons near Bose statistics

    International Nuclear Information System (INIS)

    McCabe, J.; MacKenzie, R.

    1992-01-01

    The validity of a mean-field approximation for a boson-based free anyon gas near Bose statistics is shown. The magnetic properties of the system is discussed in the approximation that the statistical magnetic field is uniform. It is proved that the anyon gas does not exhibit a Meissner effect in the domain of validity the approximation. (K.A.) 7 refs

  12. Boltzmann and Einstein: Statistics and dynamics –An unsolved ...

    Indian Academy of Sciences (India)

    The struggle of Boltzmann with the proper description of the behavior of classical macroscopic bodies in equilibrium in terms of the properties of the particles out of which they consist will be sketched. He used both a dynamical and a statistical method. However, Einstein strongly disagreed with Boltzmann's statistical method ...

  13. Adenine phosphoribosyltransferase from Sulfolobus solfataricus is an enzyme with unusual kinetic properties and a crystal structure that suggests it evolved from a 6-oxopurine phosphoribosyltransferase.

    Science.gov (United States)

    Jensen, Kaj Frank; Hansen, Michael Riis; Jensen, Kristine Steen; Christoffersen, Stig; Poulsen, Jens-Christian Navarro; Mølgaard, Anne; Kadziola, Anders

    2015-04-14

    The adenine phosphoribosyltransferase (APRTase) encoded by the open reading frame SSO2342 of Sulfolobus solfataricus P2 was subjected to crystallographic, kinetic, and ligand binding analyses. The enzyme forms dimers in solution and in the crystals, and binds one molecule of the reactants 5-phosphoribosyl-α-1-pyrophosphate (PRPP) and adenine or the product adenosine monophosphate (AMP) or the inhibitor adenosine diphosphate (ADP) in each active site. The individual subunit adopts an overall structure that resembles a 6-oxopurine phosphoribosyltransferase (PRTase) more than known APRTases implying that APRT functionality in Crenarchaeotae has its evolutionary origin in this family of PRTases. Only the N-terminal two-thirds of the polypeptide chain folds as a traditional type I PRTase with a five-stranded β-sheet surrounded by helices. The C-terminal third adopts an unusual three-helix bundle structure that together with the nucleobase-binding loop undergoes a conformational change upon binding of adenine and phosphate resulting in a slight contraction of the active site. The inhibitor ADP binds like the product AMP with both the α- and β-phosphates occupying the 5'-phosphoribosyl binding site. The enzyme shows activity over a wide pH range, and the kinetic and ligand binding properties depend on both pH and the presence/absence of phosphate in the buffers. A slow hydrolysis of PRPP to ribose 5-phosphate and pyrophosphate, catalyzed by the enzyme, may be facilitated by elements in the C-terminal three-helix bundle part of the protein.

  14. The unusual kinematics of the galaxy IC 10

    International Nuclear Information System (INIS)

    Cohen, R.J.

    1979-01-01

    Observations of neutral hydrogen emission from the galaxy IC 10 show a large outer envelope of gas more than 1 0 in extent. The emission has a velocity gradient along the major axis in the opposite sense to that of the central concentration mapped by Shostak. This unusual velocity reversal can be interpreted in terms of a warped gas-layer in normal rotation and seen face-on. (author)

  15. An unusual presentation of postpartum ovarian vein thrombosis

    International Nuclear Information System (INIS)

    Hakim, Fayaz A.; Khan, Nadra N.; Qushmaq, Khalid A.; Al-Shami, Sadiq Y.

    2007-01-01

    Ovarian vein thrombosis is a rare but potentially serious complication following childbirth. The majority of patients present during the first week postpartum, with fever and right lower quadrant abdominal pain. We report an unusual case of postpartum ovarian vein thrombosis who presented with fever, low backache, and painful thighs. A high index of suspicion is crucial to diagnose and treat this condition in order to avoid serious consequences. (author)

  16. POEMS syndrome: unusual radiographic, scintigraphic and CT features

    International Nuclear Information System (INIS)

    Narvaez, J.A.; Majos, C.; Valls, C.; Fernandez-Cabrera, L.; Narvaez, J.

    1998-01-01

    POEMS syndrome is a multisystemic disorder related to a plasma cell dyscrasia. Radiologically, this syndrome is characterized by sclerotic focal bone lesions with a normal radionuclide bone scan. We report a case of POEMS syndrome with an expansile lytic lesion in the sternum showing periosteal reaction and soft tissue mass, which revealed locally increased uptake of radiotracer in bone scintigraphy. These unusual findings and the differential diagnosis are discussed. (orig.)

  17. An Unusual Cause of Precordial Chest Pain

    Directory of Open Access Journals (Sweden)

    Sevket Ozkaya

    2013-01-01

    Full Text Available Extraskeletal chondrosarcoma in anterior mediastinum is very rare. A 45-year-old male patient was admitted to the hospital with precordial chest pain. A large and well-shaped mass in the anterior mediastinum was seen radiologically, and there was a clearly compression of the heart by the mass. The lesion was totally resected, and extraskeletal mediastinal chondrosarcoma was histopathologically diagnosed. We aimed to present and discuss the radiologic, clinic, and histopathologic features of unusual presentation of extraskeletal chondrosarcoma in a case.

  18. Microfilaria in pleural effusion: An unusual association

    Directory of Open Access Journals (Sweden)

    Rehena Sarkar

    2016-01-01

    Full Text Available Lymphatic filariasis is a major public health problem in tropical countries and India is endemic for it. However, lymphatic filariasis presenting as pleural effusion is an unusual manifestation and finding microfilaria in pleural effusion without any lung pathology is rare. We report a case of pleural effusion without any underlying lung pathology and normal blood picture. Clinical cure occurred after treatment with diethyl-carbamazepine. Filariasis should be kept in view while considering the differential diagnosis of idiopathic pleural effusion, especially in endemic countries.

  19. Hepatic Parasitic Abscess Caused by Clonorchiasis: Unusual CT Findings of Clonorchiasis

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Yun Jin; Byun, Jae Ho; Yoon, Seong Eon; Yu, Eun Sil [University of Ulsan College of Medicine, Seoul (Korea, Republic of)

    2007-02-15

    We report here on the CT findings of an unusual case of hepatic parasitic abscess that was caused by clonorchiasis; this malady mimicked cholangiocarcinoma, and there was no dilatation of the intrahepatic bile ducts. lonorchiasis is a snail-transmitted, parasitic disease of the bile ducts; this is caused by chronic infestation of liver flukes, Clonorchis sinensis, which reside mainly in the medium- and small-sized intrahepatic bile ducts. The CT, ultrasonograms and cholangiograms of clonorchiasis patients usually show diffuse, uniform, minimal or mild dilatation of the small intrahepatic bile ducts, particularly in the periphery, without dilatation of the extrahepatic bile duct. We report here on the CT findings of an unusual case of hepatic parasitic abscess caused by clonorchiasis; this malady mimicked cholangiocarcinoma, and there was no dilatation of the intrahepatic bile ducts.

  20. Hepatic Parasitic Abscess Caused by Clonorchiasis: Unusual CT Findings of Clonorchiasis

    International Nuclear Information System (INIS)

    Jang, Yun Jin; Byun, Jae Ho; Yoon, Seong Eon; Yu, Eun Sil

    2007-01-01

    We report here on the CT findings of an unusual case of hepatic parasitic abscess that was caused by clonorchiasis; this malady mimicked cholangiocarcinoma, and there was no dilatation of the intrahepatic bile ducts. lonorchiasis is a snail-transmitted, parasitic disease of the bile ducts; this is caused by chronic infestation of liver flukes, Clonorchis sinensis, which reside mainly in the medium- and small-sized intrahepatic bile ducts. The CT, ultrasonograms and cholangiograms of clonorchiasis patients usually show diffuse, uniform, minimal or mild dilatation of the small intrahepatic bile ducts, particularly in the periphery, without dilatation of the extrahepatic bile duct. We report here on the CT findings of an unusual case of hepatic parasitic abscess caused by clonorchiasis; this malady mimicked cholangiocarcinoma, and there was no dilatation of the intrahepatic bile ducts