WorldWideScience

Sample records for cluster number counts

  1. Combining cluster number counts and galaxy clustering

    CERN Document Server

    Lacasa, Fabien

    2016-01-01

    We present a detailed modelling of the joint covariance matrix between cluster number counts and the galaxy angular power spectrum. To this end, we use a Halo Model framework complemented by a Halo Occupation Distribution model (HOD), and we work in full-sky. We demonstrate the importance of accounting for non-Gaussianity to produce accurate covariance predictions, as the Gaussian part of the covariance can in fact become subdominant in certain configurations. We discuss in particular the case of the super-sample covariance (SSC), including the effects of galaxy shot-noise, halo second order bias and non-local bias, and demonstrating interesting mathematical properties. Using the joint covariance matrix and a Fisher matrix methodology, we examine the prospects of combining these two probes to constrain cosmological and HOD parameters. We find that the combination indeed results in noticeable better constraints, in particular because the cross-covariance introduces a synergy between the probes on small scales....

  2. Combining cluster number counts and galaxy clustering

    Science.gov (United States)

    Lacasa, Fabien; Rosenfeld, Rogerio

    2016-08-01

    The abundance of clusters and the clustering of galaxies are two of the important cosmological probes for current and future large scale surveys of galaxies, such as the Dark Energy Survey. In order to combine them one has to account for the fact that they are not independent quantities, since they probe the same density field. It is important to develop a good understanding of their correlation in order to extract parameter constraints. We present a detailed modelling of the joint covariance matrix between cluster number counts and the galaxy angular power spectrum. We employ the framework of the halo model complemented by a Halo Occupation Distribution model (HOD). We demonstrate the importance of accounting for non-Gaussianity to produce accurate covariance predictions. Indeed, we show that the non-Gaussian covariance becomes dominant at small scales, low redshifts or high cluster masses. We discuss in particular the case of the super-sample covariance (SSC), including the effects of galaxy shot-noise, halo second order bias and non-local bias. We demonstrate that the SSC obeys mathematical inequalities and positivity. Using the joint covariance matrix and a Fisher matrix methodology, we examine the prospects of combining these two probes to constrain cosmological and HOD parameters. We find that the combination indeed results in noticeably better constraints, with improvements of order 20% on cosmological parameters compared to the best single probe, and even greater improvement on HOD parameters, with reduction of error bars by a factor 1.4-4.8. This happens in particular because the cross-covariance introduces a synergy between the probes on small scales. We conclude that accounting for non-Gaussian effects is required for the joint analysis of these observables in galaxy surveys.

  3. Expected Number Counts of Radio Galaxy Clusters

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Clusters of galaxies may contain radio sources if they still experience successive mergers at present. This has been confirmed by radio observations that about 30% of nearby clusters possess radio halos. We present a theoretical prediction of radio cluster counts using a semi-analytic approach which incorporates the empirical correlation between radio power and dynamical mass of clusters, and the cluster mass function described by the Press-Schechter formalism. The total population of radio clusters over the whole sky and their redshift distribution are given.

  4. Calibrating Cluster Number Counts with CMB lensing

    CERN Document Server

    Louis, Thibaut

    2016-01-01

    CMB Stage-4 experiments will reduce the uncertainties on the gravitational lensing potential by an order of magnitude compared to current measurements, and will also produce a Sunyaev-Zel'dovich (SZ) cluster catalog containing $\\sim10^{5}$ objects, two orders of magnitudes higher than what is currently available. In this paper we propose to combine these two observables and show that it is possible to calibrate the masses of the full Stage-4 cluster catalog internally owing to the high signal to noise measurement of the CMB lensing convergence field. We find that a CMB Stage-4 experiment will constrain the hydrostatic bias parameter to sub-percent accuracy. We also show constraints on a non parametric $Y-M$ relationship which could be used to study its evolution with mass and redshift. Finally we present a joint likelihood for thermal SZ (tSZ) flux and mass measurements, and show that it could lead to a $\\sim5\\sigma$ detection of the lower limit on the sum of the neutrino masses in the normal hierarchy ($\\sum...

  5. The SWIFT AGN and Cluster Survey I: Number Counts of AGN and Galaxy Clusters

    CERN Document Server

    Dai, Xinyu; Kochanek, Christopher S; Nugent, Jenna M; Bregman, Joel N

    2015-01-01

    The Swift AGN and Cluster Survey (SACS) uses 125 deg^2 of Swift XRT serendipitous fields with variable depths surrounding gamma-ray bursts to provide a medium depth (4e-15 erg/s/cm^2) and area survey filling the gap between deep, narrow Chandra/XMM-Newton surveys and wide, shallow ROSAT surveys. Here we present a catalog of 22,563 point sources and 442 extended sources and examine the number counts of the AGN and galaxy cluster populations. SACS provides excellent constraints on the AGN number counts at the bright end with negligible uncertainties due to cosmic variance, and these constraints are consistent with previous measurements. We use Wise mid-infrared (MIR) colors to classify the sources. For AGN we can roughly separate the point sources into MIR-red and MIR-blue AGN, finding roughly equal numbers of each type in the soft X-ray band (0.5-2 keV), but fewer MIR-blue sources in the hard X-ray band (2-8 keV). The cluster number counts, with 5% uncertainties from cosmic variance, are also consistent with p...

  6. The Hawaii SCUBA-2 Lensing Cluster Survey: Number Counts and Submillimeter Flux Ratios

    CERN Document Server

    Hsu, Li-Yen; Chen, Chian-Chou; Barger, Amy; Wang, Wei-Hao

    2016-01-01

    We present deep number counts at 450 $\\mu$m and 850 $\\mu$m using the SCUBA-2 camera on the James Clerk Maxwell Telescope. We combine data for six lensing cluster fields and three blank fields to measure the counts over a wide flux range at each wavelength. Thanks to the lensing magnification, our measurements extends to fluxes fainter than 1 mJy and 0.2 mJy at 450 $\\mu$m and 850 $\\mu$m, respectively. Our combined data highly constrain the faint end of the number counts. Integrating our counts shows that the majority of the extragalactic background light (EBL) at each wavelength is contributed by faint sources with $L_{\\rm IR} < 10^{12} L_{\\odot }$, corresponding to luminous infrared galaxies (LIRGs) or normal galaxies. By comparing our result with the 500 $\\mu$m stacking of $K$-selected sources from the literature, we conclude that the $K$-selected LIRGs and normal galaxies still cannot fully account for the EBL that originates from sources with $L_{\\rm IR} < 10^{12} L_{\\odot }$. This suggests that many...

  7. Joint likelihood function of cluster number counts and weak lensing power spectrum

    CERN Document Server

    Takada, Masahiro

    2013-01-01

    A coherent over- or under-density contrast across a finite survey volume causes an upward- or downward- fluctuation in the number of halos. This fluctuation in halo number adds a significant co-variant scatter in the observed amplitudes of weak lensing power spectrum at nonlinear, small scales. Because of this covariance, the amount of information that can be extracted from a measurement of the weak lensing power spectrum is significantly smaller than naive estimates. In this paper, we show that by measuring both the number counts of clusters and the power spectrum in the same survey region, we can mitigate this loss of information and significantly enhance the scientific return from the upcoming surveys. First, using the halo model approach, we derive the joint likelihood function of the halo number counts and the weak lensing power spectrum, taking into account the super-sample co-variance effect on the two observables. We show that the analytical model matches the distributions measured from 1000 realizati...

  8. Combined analysis of galaxy cluster number count, thermal Sunyaev-Zel'dovich power spectrum, and bispectrum

    Science.gov (United States)

    Hurier, G.; Lacasa, F.

    2017-08-01

    The thermal Sunyaev-Zel'dovich (tSZ) effect is a powerful probe of the evolution of structures in the universe, and is thus highly sensitive to cosmological parameters σ8 and Ωm, though its power is hampered by the current uncertainties on the cluster mass calibration. In this analysis we revisit constraints on these cosmological parameters as well as the hydrostatic mass bias, by performing (i) a robust estimation of the tSZ power-spectrum, (ii) a complete modeling and analysis of the tSZ bispectrum, and (iii) a combined analysis of galaxy clusters number count, tSZ power spectrum, and tSZ bispectrum. From this analysis, we derive as final constraints σ8 = 0.79 ± 0.02, Ωm = 0.29 ± 0.02, and (1-b) = 0.71 ± 0.07. These results favor a high value for the hydrostatic mass bias compared to numerical simulations and weak-lensing based estimations. They are furthermore consistent with both previous tSZ analyses, CMB derived cosmological parameters, and ancillary estimations of the hydrostatic mass bias.

  9. Resolved SZE Cluster Count

    Institute of Scientific and Technical Information of China (English)

    Jia-Yu Tang; Zu-Hui Fan

    2003-01-01

    We study the counts of resolved SZE (Sunyaev-Zel'dovich effect) clus-ters expected from an interferometric survey in different cosmological models underdifferent conditions. The self-similar universal gas model and Press-Schechter massfunction are used. We take the observing frequency to be 90 GHz, and consider twodish diameters, 1.2 m and 2.5 m. We calculate the number density of the galaxyclusters dN/(dΩdz) at a high flux limit Slimv = 100mJy and at a relative lowSlimv = 10 mJy. The total numbers of SZE clusters N in two low-Ω0 models arecompared. The results show that the influence of the resolved effect depends notonly on D, but also on Slimv: at a given D, the effect is more significant for a highthan for a low Slim Also, the resolved effect for a flat universe is more impressivethan that for an open universe. For D = 1.2m and Slimv= 10mJy, the resolvedeffect is very weak. Considering the designed interferometers which will be used tosurvey SZE clusters, we find that the resolved effect is insignificant when estimatingthe expected yield of the SZE cluster surveys.

  10. Spherical collapse model and cluster number counts in power-law f(T) gravity

    Science.gov (United States)

    Malekjani, M.; Basilakos, S.; Heidari, N.

    2017-04-01

    We study the spherical collapse model in the framework of spatially flat power law f(T) ∝ (- T)b gravity model. We find that the linear and non-linear growth of spherical overdensities of this particular f(T) model are affected by the power-law parameter b. Finally, we compute the predicted number counts of virialized haloes in order to distinguish the current f(T) model from the expectations of the concordance Λ cosmology. Specifically, the present analysis suggests that the f(T) gravity model with positive (negative) b predicts more (less) virialized objects with respect to those of Λ cold dark matter.

  11. On Counting the Rational Numbers

    Science.gov (United States)

    Almada, Carlos

    2010-01-01

    In this study, we show how to construct a function from the set N of natural numbers that explicitly counts the set Q[superscript +] of all positive rational numbers using a very intuitive approach. The function has the appeal of Cantor's function and it has the advantage that any high school student can understand the main idea at a glance…

  12. Faint Submillimeter Galaxies Revealed by Multifield Deep ALMA Observations: Number Counts, Spatial Clustering, and Dark Submillimeter Emitters

    CERN Document Server

    Ono, Yoshiaki; Kurono, Yasutaka; Momose, Rieko

    2014-01-01

    We present the statistics of faint submillimeter/millimeter galaxies (SMGs) and serendipitous detections of submillimeter/millimeter emitters (SMEs) with no multi-wavelength continuum counterpart revealed by the deep ALMA observations. We identify faint SMGs with flux densities of 0.1-1.0 mJy in the deep Band 6 and Band 7 maps of 10 independent fields that reduce cosmic variance effects. The differential number counts at 1.2 mm are found to increase with decreasing flux density down to 0.1 mJy. Our number counts indicate that the faint (0.1-1.0 mJy, or SFR_IR ~ 30-300 Msun/yr) SMGs contribute nearly a half of the extragalactic background light (EBL), while the remaining half of the EBL is mostly contributed by very faint sources with flux densities of 1 mJy) SMGs, but comparable with abundant high-z star-forming populations such as sBzKs, LBGs, and LAEs. Finally, we report the serendipitous detections of SMEs with continuum counterparts neither in our 1.2 mm-band nor multi-wavelength images including ultra de...

  13. Faint submillimeter galaxies revealed by multifield deep ALMA observations: number counts, spatial clustering, and a dark submillimeter line emitter

    Energy Technology Data Exchange (ETDEWEB)

    Ono, Yoshiaki; Ouchi, Masami; Momose, Rieko [Institute for Cosmic Ray Research, The University of Tokyo, Kashiwa, Chiba 277-8582 (Japan); Kurono, Yasutaka, E-mail: ono@icrr.u-tokyo.ac.jp [Joint ALMA Observatory, Alonso de Cordova 3107, Vitacura, Santiago 763-0355 (Chile)

    2014-11-01

    We present the statistics of faint submillimeter/millimeter galaxies (SMGs) and serendipitous detections of a submillimeter/millimeter line emitter (SLE) with no multi-wavelength continuum counterpart revealed by the deep ALMA observations. We identify faint SMGs with flux densities of 0.1-1.0 mJy in the deep Band-6 and Band-7 maps of 10 independent fields that reduce cosmic variance effects. The differential number counts at 1.2 mm are found to increase with decreasing flux density down to 0.1 mJy. Our number counts indicate that the faint (0.1-1.0 mJy, or SFR{sub IR} ∼ 30-300 M {sub ☉} yr{sup –1}) SMGs contribute nearly a half of the extragalactic background light (EBL), while the remaining half of the EBL is mostly contributed by very faint sources with flux densities of <0.1 mJy (SFR{sub IR} ≲ 30 M {sub ☉} yr{sup –1}). We conduct counts-in-cells analysis with multifield ALMA data for the faint SMGs, and obtain a coarse estimate of galaxy bias, b {sub g} < 4. The galaxy bias suggests that the dark halo masses of the faint SMGs are ≲ 7 × 10{sup 12} M {sub ☉}, which is smaller than those of bright (>1 mJy) SMGs, but consistent with abundant high-z star-forming populations, such as sBzKs, LBGs, and LAEs. Finally, we report the serendipitous detection of SLE-1, which has no continuum counterparts in our 1.2 mm-band or multi-wavelength images, including ultra deep HST/WFC3 and Spitzer data. The SLE has a significant line at 249.9 GHz with a signal-to-noise ratio of 7.1. If the SLE is not a spurious source made by the unknown systematic noise of ALMA, the strong upper limits of our multi-wavelength data suggest that the SLE would be a faint galaxy at z ≳ 6.

  14. Counting problems for number rings

    NARCIS (Netherlands)

    Brakenhoff, Johannes Franciscus

    2009-01-01

    In this thesis we look at three counting problems connected to orders in number fields. First we study the probability that for a random polynomial f in Z[X] the ring Z[X]/f is the maximal order in Q[X]/f. Connected to this is the probability that a random polynomial has a squarefree discriminant. T

  15. The Brera Multi-scale Wavelet HRI Cluster Survey: I Selection of the Sample and Number Counts

    CERN Document Server

    Moretti, A; Campana, S; Lazzati, D; Panzera, M R; Tagliaferri, G; Arena, S; Braglia, F; Dell'Antonio, I; Longhetti, M

    2004-01-01

    We describe the construction of the Brera Multi-scale Wavelet (BMW) HRI Cluster Survey, a deep sample of serendipitous X-ray selected clusters of galaxies based on the ROSAT HRI archive. This is the first cluster catalog exploiting the high angular resolution of this instrument. Cluster candidates are selected on the basis of their X-ray extension only, a parameter which is well measured by the BMW wavelet detection algorithm. The survey includes 154 candidates over a total solid angle of ~160 deg2 at 10^{-12}erg s^{-1} cm^{-2} and ~80 deg^2 at 1.8*10^{-13} erg s^{-1}$ cm^{-2}. At the same time, a fairly good sky coverage in the faintest flux bins (3-5*10^{-14}erg s^{-1} cm^{-2}) gives this survey the capability to detect a few clusters with z\\sim 1-1.2, depending on evolution. We present the results of extensive Monte Carlo simulations, providing a complete statistical characterization of the survey selection function and contamination level. We also present a new estimate of the surface density of clusters ...

  16. Vector perturbations of galaxy number counts

    Science.gov (United States)

    Durrer, Ruth; Tansella, Vittorio

    2016-07-01

    We derive the contribution to relativistic galaxy number count fluctuations from vector and tensor perturbations within linear perturbation theory. Our result is consistent with the the relativistic corrections to number counts due to scalar perturbation, where the Bardeen potentials are replaced with line-of-sight projection of vector and tensor quantities. Since vector and tensor perturbations do not lead to density fluctuations the standard density term in the number counts is absent. We apply our results to vector perturbations which are induced from scalar perturbations at second order and give numerical estimates of their contributions to the power spectrum of relativistic galaxy number counts.

  17. Vector perturbations of galaxy number counts

    CERN Document Server

    Durrer, Ruth

    2016-01-01

    We derive the contribution to relativistic galaxy number count fluctuations from vector and tensor perturbations within linear perturbation theory. Our result is consistent with the the relativistic corrections to number counts due to scalar perturbation, where the Bardeen potentials are replaced with line-of-sight projection of vector and tensor quantities. Since vector and tensor perturbations do not lead to density fluctuations the standard density term in the number counts is absent. We apply our results to vector perturbations which are induced from scalar perturbations at second order and give numerical estimates of their contributions to the power spectrum of relativistic galaxy number counts.

  18. Quantum abacus for counting and factorizing numbers

    Science.gov (United States)

    Suslov, M. V.; Lesovik, G. B.; Blatter, G.

    2011-05-01

    We generalize the binary quantum counting algorithm of Lesovik, Suslov, and Blatter [Phys. Rev. APLRAAN1050-294710.1103/PhysRevA.82.012316 82, 012316 (2010)] to higher counting bases. The algorithm makes use of qubits, qutrits, and qudits to count numbers in a base-2, base-3, or base-d representation. In operating the algorithm, the number nnumber n in the base-d representation; the inverse transformation is fully quantum at the level of individual qudits, while a simpler semiclassical version can be used on the level of qudit registers. Combining registers of qubits, qutrits, and qudits, where d is a prime number, with a simpler single-shot measurement allows us to find the powers of 2, 3, and other primes d in the number n. We show that the counting task naturally leads to the shift operation and an algorithm based on the quantum Fourier transformation. We discuss possible implementations of the algorithm using quantum spin-d systems, d-well systems, and their emulation with spin-1/2 or double-well systems. We establish the analogy between our counting algorithm and the phase estimation algorithm and make use of the latter’s performance analysis in stabilizing our scheme. Applications embrace a quantum metrological scheme to measure voltage (an analog to digital converter) and a simple procedure to entangle multiparticle states.

  19. MOIRCS Deep Survey. I: DRG Number Counts

    CERN Document Server

    Kajisawa, M; Suzuki, R; Tokoku, C; Uchimoto, Y K; Yoshikawa, T; Akiyama, M; Ichikawa, T; Ouchi, M; Omata, K; Tanaka, I; Nishimura, T; Yamada, T; Kajisawa, Masaru; Konishi, Masahiro; Suzuki, Ryuji; Tokoku, Chihiro; Uchimoto, Yuka Katsuno; Yoshikawa, Tomohiro; Akiyama, Masayuki; Ichikawa, Takashi; Ouchi, Masami; Omata, Koji; Tanaka, Ichi; Nishimura, Tetsuo; Yamada, Toru

    2006-01-01

    We use very deep near-infrared imaging data taken with Multi-Object InfraRed Camera and Spectrograph (MOIRCS) on the Subaru Telescope to investigate the number counts of Distant Red Galaxies (DRGs). We have observed a 4x7 arcmin^2 field in the Great Observatories Origins Deep Survey North (GOODS-N), and our data reach J=24.6 and K=23.2 (5sigma, Vega magnitude). The surface density of DRGs selected by J-K>2.3 is 2.35+-0.31 arcmin^-2 at K22 is smaller than that expected from the number counts at the brighter magnitude. The result indicates that while there are many bright galaxies at 222 suggest that the mass-dependent color distribution, where most of low-mass galaxies are blue while more massive galaxies tend to have redder colors, had already been established at that epoch.

  20. Cosmological constraints from Subaru weak lensing cluster counts

    CERN Document Server

    Hamana, Takashi; Koike, Michitaro; Miller, Lance

    2015-01-01

    We present results of weak lensing cluster counts obtained from 11 sq.deg SuprimeCam data. Although the area is much smaller than previous work dealing with weak lensing peak statistics, the number density of galaxies usable for weak lensing analysis is about twice as large as those. The higher galaxy number density reduces the noise in the weak lensing mass maps, and thus increases the signal-to-noise ratio of peaks of the lensing signal due to massive clusters. This enables us to construct a weak lensing selected cluster sample by adopting a high threshold S/N, such that the contamination rate due to false signals is small. We find 6 peaks with S/N>5. For all the peaks, previously identified clusters of galaxies are matched within a separation of 1 arcmin, demonstrating good correspondence between the peaks and clusters of galaxies. We evaluate the statistical error using mock weak lensing data, and find Npeak=6+/-3.1 in an effective area of 9.0 sq.deg. We compare the measured weak lensing cluster counts wi...

  1. Number Counts and Non-Gaussianity

    CERN Document Server

    Shandera, Sarah; Scott, Pat; Galarza, Jhon Yana

    2013-01-01

    We describe a general procedure for using number counts of any object to constrain the probability distribution of the primordial fluctuations, allowing for generic weak non-Gaussianity. We apply this procedure to use limits on the abundance of primordial black holes and dark matter ultracompact minihalos (UCMHs) to characterize the allowed statistics of primordial fluctuations on very small scales. We present constraints on the power spectrum and the amplitude of the skewness for two different families of non-Gaussian distributions, distinguished by the relative importance of higher moments. Although primordial black holes probe the smallest scales, ultracompact minihalos provide significantly stronger constraints on the power spectrum and so are more likely to eventually provide small-scale constraints on non-Gaussianity.

  2. Enhanced peptide quantification using spectral count clustering and cluster abundance

    Directory of Open Access Journals (Sweden)

    Lee Seungmook

    2011-10-01

    Full Text Available Abstract Background Quantification of protein expression by means of mass spectrometry (MS has been introduced in various proteomics studies. In particular, two label-free quantification methods, such as spectral counting and spectra feature analysis have been extensively investigated in a wide variety of proteomic studies. The cornerstone of both methods is peptide identification based on a proteomic database search and subsequent estimation of peptide retention time. However, they often suffer from restrictive database search and inaccurate estimation of the liquid chromatography (LC retention time. Furthermore, conventional peptide identification methods based on the spectral library search algorithms such as SEQUEST or SpectraST have been found to provide neither the best match nor high-scored matches. Lastly, these methods are limited in the sense that target peptides cannot be identified unless they have been previously generated and stored into the database or spectral libraries. To overcome these limitations, we propose a novel method, namely Quantification method based on Finding the Identical Spectral set for a Homogenous peptide (Q-FISH to estimate the peptide's abundance from its tandem mass spectrometry (MS/MS spectra through the direct comparison of experimental spectra. Intuitively, our Q-FISH method compares all possible pairs of experimental spectra in order to identify both known and novel proteins, significantly enhancing identification accuracy by grouping replicated spectra from the same peptide targets. Results We applied Q-FISH to Nano-LC-MS/MS data obtained from human hepatocellular carcinoma (HCC and normal liver tissue samples to identify differentially expressed peptides between the normal and disease samples. For a total of 44,318 spectra obtained through MS/MS analysis, Q-FISH yielded 14,747 clusters. Among these, 5,777 clusters were identified only in the HCC sample, 6,648 clusters only in the normal tissue sample

  3. Particle number counting statistics in ideal Bose gases

    National Research Council Canada - National Science Library

    Christoph Weiss; Martin Wilkens

    1997-01-01

    We discuss the exact particle number counting statistics of degenerate ideal Bose gases in the microcanonical, canonical, and grand-canonical ensemble, respectively, for various trapping potentials...

  4. Elliptic Tales Curves, Counting, and Number Theory

    CERN Document Server

    Ash, Avner

    2012-01-01

    Elliptic Tales describes the latest developments in number theory by looking at one of the most exciting unsolved problems in contemporary mathematics--the Birch and Swinnerton-Dyer Conjecture. The Clay Mathematics Institute is offering a prize of 1 million to anyone who can discover a general solution to the problem. In this book, Avner Ash and Robert Gross guide readers through the mathematics they need to understand this captivating problem. The key to the conjecture lies in elliptic curves, which are cubic equations in two variables. These equations may appear simple, yet they arise from

  5. Higher order relativistic galaxy number counts: dominating terms

    CERN Document Server

    Nielsen, Jeppe Trøst

    2016-01-01

    We review the number counts to second order concentrating on the terms which dominate on sub horizon scales. We re-derive the result for these terms and compare it with the different versions found in the literature. We generalize our derivation to higher order terms, especially the third order number counts which are needed to compute the 1-loop contribution to the power spectrum.

  6. Magic Numbers of Silicon Clusters

    OpenAIRE

    Pan, Jun; Ramakrishna, Mushti V.

    1994-01-01

    A structural model for intermediate sized silicon clusters is proposed that is able to generate unique structures without any dangling bonds. This structural model consists of bulk-like core of five atoms surrounded by fullerene-like surface. Reconstruction of the ideal fullerene geometry results in the formation of crown atoms surrounded by $\\pi$-bonded dimer pairs. This model yields unique structures for \\Si{33}, \\Si{39}, and \\Si{45} clusters without any dangling bonds and hence explains wh...

  7. Cosmology with velocity dispersion counts: an alternative to measuring cluster halo masses

    Science.gov (United States)

    Caldwell, C. E.; McCarthy, I. G.; Baldry, I. K.; Collins, C. A.; Schaye, J.; Bird, S.

    2016-11-01

    The evolution of galaxy cluster counts is a powerful probe of several fundamental cosmological parameters. A number of recent studies using this probe have claimed tension with the cosmology preferred by the analysis of the Planck primary cosmic microwave background (CMB) data, in the sense that there are fewer clusters observed than predicted based on the primary CMB cosmology. One possible resolution to this problem is systematic errors in the absolute halo mass calibration in cluster studies, which is required to convert the standard theoretical prediction (the halo mass function) into counts as a function of the observable (e.g. X-ray luminosity, Sunyaev-Zel'dovich flux, and optical richness). Here we propose an alternative strategy, which is to directly compare predicted and observed cluster counts as a function of the one-dimensional velocity dispersion of the cluster galaxies. We argue that the velocity dispersion of groups/clusters can be theoretically predicted as robustly as mass but, unlike mass, it can also be directly observed, thus circumventing the main systematic bias in traditional cluster counts studies. With the aid of the BAHAMAS suite of cosmological hydrodynamical simulations, we demonstrate the potential of the velocity dispersion counts for discriminating even similar Λ cold dark matter models. These predictions can be compared with the results from existing redshift surveys such as the highly complete Galaxy And Mass Assembly survey, and upcoming wide-field spectroscopic surveys such as the Wide Area Vista Extragalactic Survey and the Dark Energy Survey Instrument.

  8. Pixel-Cluster Counting Luminosity Measurement In ATLAS

    CERN Document Server

    McCormack, William Patrick; The ATLAS collaboration

    2016-01-01

    A precision measurement of the delivered luminosity is a key component of the ATLAS physics program at the Large Hadron Collider (LHC). A fundamental ingredient of the strategy to control the systematic uncertainties affecting the absolute luminosity has been to compare the measure- ments of several luminometers, most of which use more than one counting technique. The level of consistency across the various methods provides valuable cross-checks as well as an estimate of the detector-related systematic uncertainties. This poster describes the development of a luminosity algorithm based on pixel-cluster counting in the recently installed ATLAS inner b-layer (IBL), using data recorded during the 2015 pp run at the LHC. The noise and background contamination of the luminosity-associated cluster count is minimized by a multi-component fit to the measured cluster-size distribution in the forward pixel modules of the IBL. The linearity, long-term stability and statistical precision of the cluster- counting method a...

  9. Pixel-Cluster Counting Luminosity Measurement in ATLAS

    CERN Document Server

    McCormack, William Patrick; The ATLAS collaboration

    2016-01-01

    A precision measurement of the delivered luminosity is a key component of the ATLAS physics program at the Large Hadron Collider (LHC). A fundamental ingredient of the strategy to control the systematic uncertainties affecting the absolute luminosity has been to compare the measurements of several luminometers, most of which use more than one counting technique. The level of consistency across the various methods provides valuable cross-checks as well as an estimate of the detector-related systematic uncertainties. This poster describes the development of a luminosity algorithm based on pixel-cluster counting in the recently installed ATLAS inner b-layer (IBL), using data recorded during the 2015 pp run at the LHC. The noise and background contamination of the luminosity-associated cluster count is minimized by a multi-component fit to the measured cluster-size distribution in the forward pixel modules of the IBL. The linearity, long-term stability and statistical precision of the cluster-counting method are ...

  10. Submillimeter Number Counts From Statistical Analysis of BLAST Maps

    CERN Document Server

    Patanchon, Guillaume; Bock, James J; Chapin, Edward L; Devlin, Mark J; Dicker, Simon R; Griffin, Matthew; Gundersen, Joshua O; Halpern, Mark; Hargrave, Peter C; Hughes, David H; Klein, Jeff; Marsden, Gaelen; Mauskopf, Philip; Moncelsi, Lorenzo; Netterfield, Calvin B; Olmi, Luca; Pascale, Enzo; Rex, Marie; Scott, Douglas; Semisch, Christopher; Thomas, Nicholas; Truch, Matthew D P; Tucker, Carole; Tucker, Gregory S; Viero, Marco P; Wiebe, Donald V

    2009-01-01

    We describe the application of a statistical method to estimate submillimeter galaxy number counts from the confusion limited observations of the Balloon-borne Large Aperture Submillimeter Telescope (BLAST). Our method is based on a maximum likelihood fit to the pixel histogram, sometimes called 'P(D)', an approach which has been used before to probe faint counts, the difference being that here we advocate its use even for sources with relatively high signal-to-noise ratios. This method has an advantage over standard techniques of source extraction in providing an unbiased estimate of the counts from the bright end down to flux densities well below the confusion limit. We specifically analyse BLAST observations of a roughly 10 sq. deg map centered on the Great Observatories Origins Deep Survey South field. We provide estimates of number counts at the three BLAST wavelengths, 250, 350, and 500 microns, instead of counting sources in flux bins we estimate the counts at several flux density nodes connected with ...

  11. Validity Index and number of clusters

    Directory of Open Access Journals (Sweden)

    Mohamed Fadhel Saad

    2012-01-01

    Full Text Available Clustering (or cluster analysis has been used widely in pattern recognition, image processing, and data analysis. It aims to organize a collection of data items into c clusters, such that items within a cluster are more similar to each other than they are items in the other clusters. The number of clusters c is the most important parameter, in the sense that the remaining parameters have less influence on the resulting partition. To determine the best number of classes several methods were made, and are called validity index. This paper presents a new validity index for fuzzy clustering called a Modified Partition Coefficient And Exponential Separation (MPCAES index. The efficiency of the proposed MPCAES index is compared with several popular validity indexes. More information about these indexes is acquired in series of numerical comparisons and also real data Iris.

  12. Galaxy number counts and implications for strong lensing

    NARCIS (Netherlands)

    Fassnacht, C. D.; Koopmans, L. V. E.; Wong, K. C.

    2011-01-01

    We compare galaxy number counts in Advanced Camera for Surveys (ACS) fields containing moderate-redshift (0.2

  13. SXDF-ALMA 2 arcmin$^2$ Deep Survey: 1.1-mm Number Counts

    CERN Document Server

    Hatsukade, Bunyo; Umehata, Hideki; Aretxaga, Itziar; Caputi, Karina I; Dunlop, James S; Ikarashi, Soh; Iono, Daisuke; Ivison, Rob J; Lee, Minju; Makiya, Ryu; Matsuda, Yuichi; Motohara, Kentaro; Nakanishi, Kouichiro; Ohta, Kouji; Tadaki, Ken-ich; Tamura, Yoichi; Wang, Wei-Hao; Wilson, Grant W; Yamaguchi, Yuki; Yun, Min S

    2016-01-01

    We report 1.1 mm number counts revealed with the Atacama Large Millimeter/submillimeter Array (ALMA) in the Subaru/XMM-Newton Deep Survey Field (SXDF). The advent of ALMA enables us to reveal millimeter-wavelength number counts down to the faint end without source confusion. However, previous studies are based on the ensemble of serendipitously-detected sources in fields originally targeting different sources and could be biased due to the clustering of sources around the targets. We derive number counts in the flux range of 0.2-2 mJy by using 23 (>=4sigma) sources detected in a continuous 2.0 arcmin$^2$ area of the SXDF. The number counts are consistent with previous results within errors, suggesting that the counts derived from serendipitously-detected sources are not significantly biased, although there could be field-to-field variation due to the small survey area. By using the best-fit function of the number counts, we find that ~40% of the extragalactic background light at 1.1 mm is resolved at S(1.1mm)...

  14. Estimating the Number of Clusters via Normalized Cluster Instability

    OpenAIRE

    Haslbeck, Jonas M. B.; Wulff, Dirk U.

    2016-01-01

    We improve existing instability-based methods for the selection of the number of clusters $k$ in cluster analysis by normalizing instability. In contrast to existing instability methods which only perform well for bounded sequences of small $k$, our method performs well across the whole sequence of possible $k$. In addition, we compare for the first time model-based and model-free variants of $k$ selection via cluster instability and find that their performance is similar. We make our method ...

  15. Correlation functions quantify super-resolution images and estimate apparent clustering due to over-counting

    CERN Document Server

    Veatch, Sarah; Shelby, Sarah; Chiang, Ethan; Holowka, David; Baird, Barbara

    2011-01-01

    We present an analytical method to quantify clustering in super-resolution localization images of static surfaces in two dimensions. The method also describes how over-counting of labeled molecules contributes to apparent self-clustering and how the effective lateral resolution of an image can be determined. This treatment applies to clustering of proteins and lipids in membranes, where there is significant interest in using super-resolution localization techniques to probe membrane heterogeneity. When images are quantified using pair correlation functions, the magnitude of apparent clustering due to over-counting will vary inversely with the surface density of labeled molecules and does not depend on the number of times an average molecule is counted. Over-counting does not yield apparent co-clustering in double label experiments when pair cross-correlation functions are measured. We apply our analytical method to quantify the distribution of the IgE receptor (Fc{\\epsilon}RI) on the plasma membranes of chemi...

  16. Cosmology with velocity dispersion counts: an alternative to measuring cluster halo masses

    CERN Document Server

    Caldwell, C E; Baldry, I K; Collins, C A; Schaye, J; Bird, S

    2016-01-01

    The evolution of galaxy cluster counts is a powerful probe of several fundamental cosmological parameters. A number of recent studies using this probe have claimed tension with the cosmology preferred by the analysis of the Planck primary CMB data, in the sense that there are fewer clusters observed than predicted based on the primary CMB cosmology. One possible resolution to this problem is systematic errors in the absolute halo mass calibration in cluster studies, which is required to convert the standard theoretical prediction (the halo mass function) into counts as a function of the observable (e.g., X-ray luminosity, Sunyaev-Zel'dovich flux, optical richness). Here we propose an alternative strategy, which is to directly compare predicted and observed cluster counts as a function of the one-dimensional velocity dispersion of the cluster galaxies. We argue that the velocity dispersion of groups/clusters can be theoretically predicted as robustly as mass but, unlike mass, it can also be directly observed, ...

  17. What do cluster counts really tell us about the Universe?

    CERN Document Server

    Smith, Robert E

    2011-01-01

    We study the covariance matrix of the cluster mass function in cosmology. We adopt a two-line attack: firstly, we employ the counts-in-cells framework to derive an analytic expression for the covariance of the mass function. Secondly, we use a large ensemble of N-body simulations in the LCDM framework to test this. Our theoretical results show that the covariance can be written as the sum of two terms: a Poisson term, which dominates in the limit of rare clusters; and a sample variance term, which dominates for more abundant clusters. Our expressions are analogous to those of Hu & Kravtsov (2003) for multiple cells and a single mass tracer. Calculating the covariance depends on: the mass function and bias of clusters, and the variance of mass fluctuations within the survey volume. The predictions show that there is a strong bin-to-bin covariance between measurements. In terms of the cross-correlation coefficient, we find r~0.5 for haloes with M3e14 Msol, otherwise the information content of a survey of si...

  18. Correlation functions quantify super-resolution images and estimate apparent clustering due to over-counting.

    Directory of Open Access Journals (Sweden)

    Sarah L Veatch

    Full Text Available We present an analytical method using correlation functions to quantify clustering in super-resolution fluorescence localization images and electron microscopy images of static surfaces in two dimensions. We use this method to quantify how over-counting of labeled molecules contributes to apparent self-clustering and to calculate the effective lateral resolution of an image. This treatment applies to distributions of proteins and lipids in cell membranes, where there is significant interest in using electron microscopy and super-resolution fluorescence localization techniques to probe membrane heterogeneity. When images are quantified using pair auto-correlation functions, the magnitude of apparent clustering arising from over-counting varies inversely with the surface density of labeled molecules and does not depend on the number of times an average molecule is counted. In contrast, we demonstrate that over-counting does not give rise to apparent co-clustering in double label experiments when pair cross-correlation functions are measured. We apply our analytical method to quantify the distribution of the IgE receptor (FcεRI on the plasma membranes of chemically fixed RBL-2H3 mast cells from images acquired using stochastic optical reconstruction microscopy (STORM/dSTORM and scanning electron microscopy (SEM. We find that apparent clustering of FcεRI-bound IgE is dominated by over-counting labels on individual complexes when IgE is directly conjugated to organic fluorophores. We verify this observation by measuring pair cross-correlation functions between two distinguishably labeled pools of IgE-FcεRI on the cell surface using both imaging methods. After correcting for over-counting, we observe weak but significant self-clustering of IgE-FcεRI in fluorescence localization measurements, and no residual self-clustering as detected with SEM. We also apply this method to quantify IgE-FcεRI redistribution after deliberate clustering by

  19. Particle number counting statistics in ideal Bose gases.

    Science.gov (United States)

    Weiss, C; Wilkens, M

    1997-11-10

    We discuss the exact particle number counting statistics of degenerate ideal Bose gases in the microcanonical, canonical, and grand-canonical ensemble, respectively, for various trapping potentials. We then invoke the Maxwell's Demon ensemble [Navez et el., Phys. Rev. Lett. (1997)] and show that for large total number of particles the root-mean-square fluctuation of the condensate occupation scales n0 / [T=Tc] r N s with scaling exponents r = 3=2, s = 1=2 for the3D harmonic oscillator trapping potential, and r = 1,s= 2=3 for the 3D box. We derive an explicit expression for r and s in terms of spatial dimension D and spectral index sigma of the single-particle energy spectrum. Our predictions also apply to systems where Bose-Einstein condensation does not occur. We point out that the condensate fluctuations in the microcanonical and canonical ensemble respect the principle of thermodynamic equivalence.

  20. Multiwavelength Number Counts of AGN in the GOODS Fields

    Science.gov (United States)

    Urry, C. M.; Treister, E.; Chatzichristou, E. T.; Van Duyne, J.; Bauer, F. E.; Alexander, D. M.; Koekemoer, A. M.; Moustakas, L. A.; Brandt, W. N.; Grogin, N. A.; Bergeron, J.; Stern, D.; Chary, R.-R.; Conselice, C. J.; Cristiani, S.

    2004-05-01

    We model the X-ray, optical, and far-infrared flux distributions of AGN in the GOODS fields, starting from hard X-ray luminosity functions and spectral energy distributions appropriate to the unified scheme for AGN. The deep optical counts measured from HST ACS images can be well explained by a unified scheme that postulates roughly 3 times as many obscured as unobscured AGN. This scenario is consistent with the observed spectroscopic and photometric redshift distributions of the GOODS AGN once selection effects are considered. The previously reported discrepancy between observed spectroscopic redshift distributions and the predictions of population synthesis models for the X-ray background (which include a similarly large number of obscured AGN) is explained by bias against the most heavily obscured AGN in both X-ray surveys and optical spectroscopic samples. We present the model predictions for the number counts of AGN in the Spitzer MIPS 24 micron and IRAC 3.6-8 micron bands. The GOODS Spitzer observations will verify whether large numbers of obscured AGN are indeed present in the early Universe; these will be very bright far-infrared sources, including some, missed by X-ray observations, that look like ultraluminous infrared galaxies. Based on observations obtained with the NASA/ESA Hubble Space Telescope, which is operated by the Association of Universities for Research in Astronomy (AURA), Inc, under NASA contract NAS5-26555. This work was supported by NASA grants HST-GO-09425(.01-A,.13-A,.26-A); NSF CAREER award AST 99-83783; NASA contract number 1224666 issued by JPL/Caltech under NASA contract 1407; ASI grant I/R/088/02; and a Royal Society University Research Fellowship.

  1. Planck 2013 results. XX. Cosmology from Sunyaev-Zeldovich cluster counts

    DEFF Research Database (Denmark)

    Ade, P. A. R.; Aghanim, N.; Armitage-Caplan, C.;

    2013-01-01

    We present constraints on cosmological parameters using number counts as a function of redshift for a sub-sample of 189 galaxy clusters from the Planck SZ (PSZ) catalogue. The PSZ is selected through the signature of the Sunyaev-Zeldovich (SZ) effect, and the sub-sample used here has a signal...... spectrum amplitude σ8 and matter density parameter Ωm in a flat ΛCDM model. We test the robustness of our estimates and find that possible biases in the Y–M relation and the halo mass function are larger than the statistical uncertainties from the cluster sample. Assuming the X-ray determined mass...

  2. The Effect of Nearby Voids on Galaxy Number Counts

    CERN Document Server

    Bucklein, Brian K; Hintz, Eric G

    2016-01-01

    The size, shape and degree of emptiness of void interiors sheds light on the details of galaxy formation. A particularly interesting question is whether void interiors are completely empty or contain a dwarf population. However the nearby voids that are most conducive for dwarf searches have large angular diameters, on the order of a steradian, making it difficult to redshift-map a statistically significant portion of their volume to the magnitude limit of dwarf galaxies. As part of addressing this problem, we investigate here the usefulness of number counts in establishing the best locations to search inside nearby (d < 300 Mpc) galaxy voids, utilizing Wolf plots of log(n < m) vs. m as the basic diagnostic. To illustrate expected signatures, we consider the signature of three void profiles, "cut out", "built up", and "universal profile" carved into Monte-Carlo Schechter function models. We then investigate the signatures of voids in the Millennium Run dark matter simulation and the Sloan Digital Sky Su...

  3. Comparing Digital Sunspot Number Counts to the New International Sunspot Numbers

    Science.gov (United States)

    Balasubramaniam, K. S.; Henry, Timothy

    2016-05-01

    The International Sunspot Numbers (ISN; Version 2) have been recently (2015) revised at the Sunspot Index and Long Term Solar Observations maintained at Royal Observatory of Belgium (http://www.sidc.be/silso/datafiles). ISN is a reconciled aggregate over several ground-based observatories, mostly using hand-drawn sunspot recordings. We make a detailed 10-year comparisons between the Improved Solar Observing Optical Network’s prototype digital data (2002-2011) and the ISN V1 (Version 1; pre-2015), and ISN V2. Over the ~ 10-year period, ISN V1 underestimates the sunspot number counts by up to 40% while the ISN V2 overestimates by a similar amount. We also compare the hand-drawn data from a single telescope at the National Solar Observatory with the digital data and ISN numbers. These comparisons reveal caveats that need to be taken into account, as sunspot numbers are used to forecast both the solar cycle and the near term climatology of solar cycle impacts on the space environment.

  4. Deep Galex Observations of the Coma Cluster: Source Catalog and Galaxy Counts

    Science.gov (United States)

    Hammer, D.; Hornschemeier, A. E.; Mobasher, B.; Miller, N.; Smith, R.; Arnouts, S.; Milliard, B.; Jenkins, L.

    2010-01-01

    We present a source catalog from deep 26 ks GALEX observations of the Coma cluster in the far-UV (FUV; 1530 Angstroms) and near-UV (NUV; 2310 Angstroms) wavebands. The observed field is centered 0.9 deg. (1.6 Mpc) south-west of the Coma core, and has full optical photometric coverage by SDSS and spectroscopic coverage to r-21. The catalog consists of 9700 galaxies with GALEX and SDSS photometry, including 242 spectroscopically-confirmed Coma member galaxies that range from giant spirals and elliptical galaxies to dwarf irregular and early-type galaxies. The full multi-wavelength catalog (cluster plus background galaxies) is 80% complete to NUV=23 and FUV=23.5, and has a limiting depth at NUV=24.5 and FUV=25.0 which corresponds to a star formation rate of 10(exp -3) solar mass yr(sup -1) at the distance of Coma. The GALEX images presented here are very deep and include detections of many resolved cluster members superposed on a dense field of unresolved background galaxies. This required a two-fold approach to generating a source catalog: we used a Bayesian deblending algorithm to measure faint and compact sources (using SDSS coordinates as a position prior), and used the GALEX pipeline catalog for bright and/or extended objects. We performed simulations to assess the importance of systematic effects (e.g. object blends, source confusion, Eddington Bias) that influence source detection and photometry when using both methods. The Bayesian deblending method roughly doubles the number of source detections and provides reliable photometry to a few magnitudes deeper than the GALEX pipeline catalog. This method is also free from source confusion over the UV magnitude range studied here: conversely, we estimate that the GALEX pipeline catalogs are confusion limited at NUV approximately 23 and FUV approximately 24. We have measured the total UV galaxy counts using our catalog and report a 50% excess of counts across FUV=22-23.5 and NUV=21.5-23 relative to previous GALEX

  5. Refined tropical curve counts and canonical bases for quantum cluster algebras

    DEFF Research Database (Denmark)

    Mandel, Travis

    We express the (quantizations of the) Gross-Hacking-Keel-Kontsevich canonical bases for cluster algebras in terms of certain (Block-Göttsche) weighted counts of tropical curves. In the process, we obtain via scattering diagram techniques a new invariance result for these Block-Göttsche counts....

  6. Refined tropical curve counts and canonical bases for quantum cluster algebras

    DEFF Research Database (Denmark)

    Mandel, Travis

    We express the (quantizations of the) Gross-Hacking-Keel-Kontsevich canonical bases for cluster algebras in terms of certain (Block-Göttsche) weighted counts of tropical curves. In the process, we obtain via scattering diagram techniques a new invariance result for these Block-Göttsche counts....

  7. Determining the Optimal Number of Clusters with the Clustergram

    Science.gov (United States)

    Fluegemann, Joseph K.; Davies, Misty D.; Aguirre, Nathan D.

    2011-01-01

    Cluster analysis aids research in many different fields, from business to biology to aerospace. It consists of using statistical techniques to group objects in large sets of data into meaningful classes. However, this process of ordering data points presents much uncertainty because it involves several steps, many of which are subject to researcher judgment as well as inconsistencies depending on the specific data type and research goals. These steps include the method used to cluster the data, the variables on which the cluster analysis will be operating, the number of resulting clusters, and parts of the interpretation process. In most cases, the number of clusters must be guessed or estimated before employing the clustering method. Many remedies have been proposed, but none is unassailable and certainly not for all data types. Thus, the aim of current research for better techniques of determining the number of clusters is generally confined to demonstrating that the new technique excels other methods in performance for several disparate data types. Our research makes use of a new cluster-number-determination technique based on the clustergram: a graph that shows how the number of objects in the cluster and the cluster mean (the ordinate) change with the number of clusters (the abscissa). We use the features of the clustergram to make the best determination of the cluster-number.

  8. Counting

    Institute of Scientific and Technical Information of China (English)

    许有国

    2005-01-01

    Most people began to count in tens because they had ten fingers on their hands. But in some countries, people counted on one hand and used the three parts of their four fingers. So they counted in twelves, not in tens.

  9. Cluster growing process and a sequence of magic numbers

    DEFF Research Database (Denmark)

    Solov'yov, Ilia; Solov'yov, Andrey V.; Greiner, Walter

    2003-01-01

    demonstrate that in this way all known global minimum structures of the Lennard-Jones (LJ) clusters can be found. Our method provides an efficient tool for the calculation and analysis of atomic cluster structure. With its use we justify the magic number sequence for the clusters of noble gas atoms......We present a new theoretical framework for modeling the cluster growing process. Starting from the initial tetrahedral cluster configuration, adding new atoms to the system, and absorbing its energy at each step, we find cluster growing paths up to the cluster sizes of more than 100 atoms. We...... and compare it with experimental observations....

  10. Planck 2013 results. XX. Cosmology from Sunyaev-Zeldovich cluster counts

    CERN Document Server

    Ade, P.A.R.; Armitage-Caplan, C.; Arnaud, M.; Ashdown, M.; Atrio-Barandela, F.; Aumont, J.; Baccigalupi, C.; Banday, A.J.; Barreiro, R.B.; Barrena, R.; Bartlett, J.G.; Battaner, E.; Battye, R.; Benabed, K.; Benoit, A.; Benoit-Levy, A.; Bernard, J.P.; Bersanelli, M.; Bielewicz, P.; Bikmaev, I.; Blanchard, A.; Bobin, J.; Bock, J.J.; Bohringer, H.; Bonaldi, A.; Bond, J.R.; Borrill, J.; Bouchet, F.R.; Bourdin, H.; Bridges, M.; Brown, M.L.; Bucher, M.; Burenin, R.; Burigana, C.; Butler, R.C.; Cardoso, J.F.; Carvalho, P.; Catalano, A.; Challinor, A.; Chamballu, A.; Chary, R.R.; Chiang, L.Y.; Chiang, H.C.; Chon, G.; Christensen, P.R.; Church, S.; Clements, D.L.; Colombi, S.; Colombo, L.P.L.; Couchot, F.; Coulais, A.; Crill, B.P.; Curto, A.; Cuttaia, F.; Da Silva, A.; Dahle, H.; Danese, L.; Davies, R.D.; Davis, R.J.; de Bernardis, P.; de Rosa, A.; de Zotti, G.; Delabrouille, J.; Delouis, J.M.; Democles, J.; Desert, F.X.; Dickinson, C.; Diego, J.M.; Dolag, K.; Dole, H.; Donzelli, S.; Dore, O.; Douspis, M.; Dupac, X.; Efstathiou, G.; Ensslin, T.A.; Eriksen, H.K.; Finelli, F.; Flores-Cacho, I.; Forni, O.; Frailis, M.; Franceschi, E.; Fromenteau, S.; Galeotta, S.; Ganga, K.; Genova-Santos, R.T.; Giard, M.; Giardino, G.; Giraud-Heraud, Y.; Gonzalez-Nuevo, J.; Gorski, K.M.; Gratton, S.; Gregorio, A.; Gruppuso, A.; Hansen, F.K.; Hanson, D.; Harrison, D.; Henrot-Versille, S.; Hernandez-Monteagudo, C.; Herranz, D.; Hildebrandt, S.R.; Hivon, E.; Hobson, M.; Holmes, W.A.; Hornstrup, A.; Hovest, W.; Huffenberger, K.M.; Hurier, G.; Jaffe, T.R.; Jaffe, A.H.; Jones, W.C.; Juvela, M.; Keihanen, E.; Keskitalo, R.; Khamitov, I.; Kisner, T.S.; Kneissl, R.; Knoche, J.; Knox, L.; Kunz, M.; Kurki-Suonio, H.; Lagache, G.; Lahteenmaki, A.; Lamarre, J.M.; Lasenby, A.; Laureijs, R.J.; Lawrence, C.R.; Leahy, J.P.; Leonardi, R.; Leon-Tavares, J.; Lesgourgues, J.; Liddle, A.; Liguori, M.; Lilje, P.B.; Linden-Vornle, M.; Lopez-Caniego, M.; Lubin, P.M.; Macias-Perez, J.F.; Maffei, B.; Maino, D.; Mandolesi, N.; Marcos-Caballero, A.; Maris, M.; Marshall, D.J.; Martin, P.G.; Martinez-Gonzalez, E.; Masi, S.; Matarrese, S.; Matthai, F.; Mazzotta, P.; Meinhold, P.R.; Melchiorri, A.; Melin, J.B.; Mendes, L.; Mennella, A.; Migliaccio, M.; Mitra, S.; Miville-Deschenes, M.A.; Moneti, A.; Montier, L.; Morgante, G.; Mortlock, D.; Moss, A.; Munshi, D.; Naselsky, P.; Nati, F.; Natoli, P.; Netterfield, C.B.; Norgaard-Nielsen, H.U.; Noviello, F.; Novikov, D.; Novikov, I.; Osborne, S.; Oxborrow, C.A.; Paci, F.; Pagano, L.; Pajot, F.; Paoletti, D.; Partridge, B.; Pasian, F.; Patanchon, G.; Perdereau, O.; Perotto, L.; Perrotta, F.; Piacentini, F.; Piat, M.; Pierpaoli, E.; Pietrobon, D.; Plaszczynski, S.; Pointecouteau, E.; Polenta, G.; Ponthieu, N.; Popa, L.; Poutanen, T.; Pratt, G.W.; Prezeau, G.; Prunet, S.; Puget, J.L.; Rachen, J.P.; Rebolo, R.; Reinecke, M.; Remazeilles, M.; Renault, C.; Ricciardi, S.; Riller, T.; Ristorcelli, I.; Rocha, G.; Roman, M.; Rosset, C.; Roudier, G.; Rowan-Robinson, M.; Rubino-Martin, J.A.; Rusholme, B.; Sandri, M.; Santos, D.; Savini, G.; Scott, D.; Seiffert, M.D.; Shellard, E.P.S.; Spencer, L.D.; Starck, J.L.; Stolyarov, V.; Stompor, R.; Sudiwala, R.; Sunyaev, R.; Sureau, F.; Sutton, D.; Suur-Uski, A.S.; Sygnet, J.F.; Tauber, J.A.; Tavagnacco, D.; Terenzi, L.; Toffolatti, L.; Tomasi, M.; Tristram, M.; Tucci, M.; Tuovinen, J.; Turler, M.; Umana, G.; Valenziano, L.; Valiviita, J.; Van Tent, B.; Vielva, P.; Villa, F.; Vittorio, N.; Wade, L.A.; Wandelt, B.D.; Weller, J.; White, M.; White, S.D.M.; Yvon, D.; Zacchei, A.; Zonca, A.

    2014-01-01

    We present constraints on cosmological parameters using number counts as a function of redshift for a sub-sample of 189 galaxy clusters from the Planck SZ (PSZ) catalogue. The PSZ is selected through the signature of the Sunyaev--Zeldovich (SZ) effect, and the sub-sample used here has a signal-to-noise threshold of seven, with each object confirmed as a cluster and all but one with a redshift estimate. We discuss the completeness of the sample and our construction of a likelihood analysis. Using a relation between mass $M$ and SZ signal $Y$ calibrated to X-ray measurements, we derive constraints on the power spectrum amplitude $\\sigma_8$ and matter density parameter $\\Omega_{\\mathrm{m}}$ in a flat $\\Lambda$CDM model. We test the robustness of our estimates and find that possible biases in the $Y$--$M$ relation and the halo mass function are larger than the statistical uncertainties from the cluster sample. Assuming the X-ray determined mass to be biased low relative to the true mass by between zero and 30%, m...

  11. Clustering Using Isoperimetric Number of Trees

    CERN Document Server

    Daneshgar, Amir; Razavi, Basir Shariat

    2012-01-01

    In this paper we propose a graph-based data clustering algorithm which is based on exact clustering of a minimum spanning tree in terms of a minimum isoperimetry criteria. We show that our basic clustering algorithm runs in $O(n \\log n)$ and with post-processing in $O(n^2)$ (worst case) time where $n$ is the size of the data set. We also show that our generalized graph model which also allows the use of potentials at vertices can be used to extract a more detailed pack of information as the {\\it outlier profile} of the data set. In this direction we show that our approach can be used to define the concept of an outlier-set in a precise way and we propose approximation algorithms for finding such sets. We also provide a comparative performance analysis of our algorithm with other related ones and we show that the new clustering algorithm (without the outlier extraction procedure) behaves quite effectively even on hard benchmarks and handmade examples.

  12. Full counting statistics of information content and particle number

    Science.gov (United States)

    Utsumi, Yasuhiro

    2017-08-01

    We consider a bipartite quantum conductor and discuss the joint probability distribution of a particle number in a subsystem and the self-information associated with the reduced density matrix of the subsystem. By extending the multicontour Keldysh Green-function technique, we calculate the Rényi entropy of a positive integer order M subjected to the particle number constraint, from which we derive the joint probability distribution. For energy-independent transmission, we derive the time dependence of the accessible entanglement entropy, or the conditional entropy. We analyze the joint probability distribution for energy-dependent transmission probability at the steady state under the coherent resonant tunneling and the incoherent sequential tunneling conditions. We also discuss the probability distribution of the efficiency, which measures the information content transferred by a single electron.

  13. Black hole state counting in LQG: A number theoretical approach

    CERN Document Server

    Agullo, Ivan; Diaz-Polo, Jacobo; Fernandez-Borja, Enrique; Villaseñor, Eduardo J S

    2008-01-01

    We give a practical method to exactly compute black hole entropy in the framework of Loop Quantum Gravity. Along the way we provide a complete characterization of the relevant sector of the spectrum of the area operator, including degeneracies, and determine the number of solutions to the projection constraint analytically. We use a computer implementation of the proposed algorithm to confirm and extend previous results on the detailed structure of the black hole degeneracy spectrum.

  14. Planck 2015 results. XXIV. Cosmology from Sunyaev-Zeldovich cluster counts

    CERN Document Server

    Ade, P A R; Arnaud, M; Ashdown, M; Aumont, J; Baccigalupi, C; Banday, A J; Barreiro, R B; Bartlett, J G; Bartolo, N; Battaner, E; Battye, R; Benabed, K; Benoît, A; Benoit-Lévy, A; Bernard, J -P; Bersanelli, M; Bielewicz, P; Bonaldi, A; Bonavera, L; Bond, J R; Borrill, J; Bouchet, F R; Bucher, M; Burigana, C; Butler, R C; Calabrese, E; Cardoso, J -F; Catalano, A; Challinor, A; Chamballu, A; Chary, R -R; Chiang, H C; Christensen, P R; Church, S; Clements, D L; Colombi, S; Colombo, L P L; Combet, C; Comis, B; Couchot, F; Coulais, A; Crill, B P; Curto, A; Cuttaia, F; Danese, L; Davies, R D; Davis, R J; de Bernardis, P; de Rosa, A; de Zotti, G; Delabrouille, J; Désert, F -X; Diego, J M; Dolag, K; Dole, H; Donzelli, S; Doré, O; Douspis, M; Ducout, A; Dupac, X; Efstathiou, G; Elsner, F; Enßlin, T A; Eriksen, H K; Falgarone, E; Fergusson, J; Finelli, F; Forni, O; Frailis, M; Fraisse, A A; Franceschi, E; Frejsel, A; Galeotta, S; Galli, S; Ganga, K; Giard, M; Giraud-Héraud, Y; Gjerløw, E; González-Nuevo, J; Górski, K M; Gratton, S; Gregorio, A; Gruppuso, A; Gudmundsson, J E; Hansen, F K; Hanson, D; Harrison, D L; Henrot-Versillé, S; Hernández-Monteagudo, C; Herranz, D; Hildebrandt, S R; Hivon, E; Hobson, M; Holmes, W A; Hornstrup, A; Hovest, W; Huffenberger, K M; Hurier, G; Jaffe, A H; Jaffe, T R; Jones, W C; Juvela, M; Keihänen, E; Keskitalo, R; Kisner, T S; Kneissl, R; Knoche, J; Kunz, M; Kurki-Suonio, H; Lagache, G; Lähteenmäki, A; Lamarre, J -M; Lasenby, A; Lattanzi, M; Lawrence, C R; Leonardi, R; Lesgourgues, J; Levrier, F; Liguori, M; Lilje, P B; Linden-Vørnle, M; López-Caniego, M; Lubin, P M; Macías-Pérez, J F; Maggio, G; Maino, D; Mandolesi, N; Mangilli, A; Martin, P G; Martínez-González, E; Masi, S; Matarrese, S; Mazzotta, P; McGehee, P; Meinhold, P R; Melchiorri, A; Melin, J -B; Mendes, L; Mennella, A; Migliaccio, M; Mitra, S; Miville-Deschênes, M -A; Moneti, A; Montier, L; Morgante, G; Mortlock, D; Moss, A; Munshi, D; Murphy, J A; Naselsky, P; Nati, F; Natoli, P; Netterfield, C B; Nørgaard-Nielsen, H U; Noviello, F; Novikov, D; Novikov, I; Oxborrow, C A; Paci, F; Pagano, L; Pajot, F; Paoletti, D; Partridge, B; Pasian, F; Patanchon, G; Pearson, T J; Perdereau, O; Perotto, L; Perrotta, F; Pettorino, V; Piacentini, F; Piat, M; Pierpaoli, E; Pietrobon, D; Plaszczynski, S; Pointecouteau, E; Polenta, G; Popa, L; Pratt, G W; Prézeau, G; Prunet, S; Puget, J -L; Rachen, J P; Rebolo, R; Reinecke, M; Remazeilles, M; Renault, C; Renzi, A; Ristorcelli, I; Rocha, G; Roman, M; Rosset, C; Rossetti, M; Roudier, G; Rubiño-Martín, J A; Rusholme, B; Sandri, M; Santos, D; Savelainen, M; Savini, G; Scott, D; Seiffert, M D; Shellard, E P S; Spencer, L D; Stolyarov, V; Stompor, R; Sudiwala, R; Sunyaev, R; Sutton, D; Suur-Uski, A -S; Sygnet, J -F; Tauber, J A; Terenzi, L; Toffolatti, L; Tomasi, M; Tristram, M; Tucci, M; Tuovinen, J; Türler, M; Umana, G; Valenziano, L; Valiviita, J; Van Tent, B; Vielva, P; Villa, F; Wade, L A; Wandelt, B D; Wehus, I K; Weller, J; White, S D M; Yvon, D; Zacchei, A; Zonca, A

    2015-01-01

    We present cluster counts and corresponding cosmological constraints from the Planck full mission data set. Our catalogue consists of 439 clusters detected via their Sunyaev-Zeldovich (SZ) signal down to a signal-to-noise of six, and is more than a factor of two larger than the 2013 Planck cluster cosmology sample. The counts are consistent with those from 2013 and yield compatible constraints under the same modelling assumptions. Taking advantage of the larger catalogue, we extend our analysis to the two-dimensional distribution in redshift and signal-to-noise. We use mass estimates from two recent studies of gravitational lensing of background galaxies by Planck clusters to provide priors on the hydrostatic bias parameter, $1-b$. In addition, we use lensing of cosmic microwave background (CMB) temperature fluctuations by Planck clusters as a third independent constraint on this parameter. These various calibrations imply constraints on the present-day amplitude of matter fluctuations in varying degrees of t...

  15. Improved Particle Identification Using Cluster Counting in a Full-Length Drift Chamber Prototype

    CERN Document Server

    Caron, Jean-François; Lu, Philip; So, Rocky; Cheaib, Racha; Martin, Jean-Pierre; Faszer, Wayne; Beaulieu, Alexandre; de Jong, Samuel; Roney, Michael; de Sangro, Riccardo; Felici, Giulietto; Finocchiaro, Giuseppe; Piccolo, Marcello

    2014-01-01

    Single-cell prototype drift chambers were built at TRIUMF and tested with a $\\sim\\unit[210]{MeV/c}$ beam of positrons, muons, and pions. A cluster-counting technique is implemented which improves the ability to distinguish muons and pions when combined with a traditional truncated-mean charge measurement. Several cluster-counting algorithms and equipment variations are tested, all showing significant improvement when combined with the traditional method. The results show that cluster counting is a feasible option for any particle physics experiment using drift chambers for particle identification. The technique does not require electronics with an overly high sampling rate. Optimal results are found with a signal smoothing time of $\\sim\\unit[5]{ns}$ corresponding to a $\\sim\\unit[100]{MHz}$ Nyquist frequency.

  16. Clusters of EAS with electron number >~ 10^4

    CERN Document Server

    Fomin, Y A; Zotov, M Yu; Fomin, Yu. A.

    2002-01-01

    We perform cluster analysis of arrival times of extensive air showers (EAS) registered with the EAS-1000 Prototype array in the period from August, 1997 till February, 1999. We present twenty cluster events each consisting of one or several EAS clusters, study the dynamics of their development, and analyze the angular distribution of EAS in clusters. We find that there may be certain correlation between EAS clusters with mean electron number $\\sim10^5$ on the one hand and gamma-ray bursts and ultrahigh energy cosmic rays on the other.

  17. Metallic Softness Influence on Magic Numbers of Clusters

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The metallic softness parameter αr0 determines the structure of the cluster and governs the rule of magic numbers. Using molecular dynamic method, the stable structures and magic numbers are determined for the clusters consisting of 13 up to 147 atoms in medium range Morse potentials, which is suitable for most of metals. As the number of atoms constituting the cluster increases, the stable structures undergo transition from face-centered (FC) to edge-centered (EC) structures. The magic numbers take ones of FC series before transition and take ones of EC series after that. The transition point from FC to EC structures depends on the value of softness parameter.

  18. Packing of protein structures in clusters with magic numbers

    DEFF Research Database (Denmark)

    Lindgård, Per-Anker; Bohr, Henrik

    1997-01-01

    of clusters containing magic numbers of secondary structures and multipla of these cluster. A scheme for the relation between the sequence information and the native fold is given. We have performed a statistical analysis of available protein structures and found agreement with the predicted preferred...

  19. DETERMINE OPTIMUM NUMBER OF COMPACT OVERLAPPED CLUSTERS USING FRLVQ TECHNIQUE

    Institute of Scientific and Technical Information of China (English)

    Xu Wenhuan; Huang Qiang; Ji Zhen; Zhang Jihong

    2005-01-01

    A method, named XHJ-method, is proposed in this letter to determine the number of clusters of a data set, which incorporates with the Fuzzy Reinforced Learning Vector Quantization (FRLVQ) technique. The simulation results show that this new method works well for the traditional iris data and an artificial data set, which contains un-equally sized and spaced clusters.

  20. More Magic Numbers in Anionic Titanium-carbon Mixed Clusters

    Institute of Scientific and Technical Information of China (English)

    ZHAU Huajin; LIU Bingchen; ZHOU Rufang; NI Guoquan

    2000-01-01

    @@ Met-Cars[1] and related transition metal-carbon clusters represent a latest breakthrough in gas phase cluster research following the discovery and macroscopic synthesis of fullerenes. Different kinds of structural growth patterns (SGPs) have been proposed to analyze the observed magic numbers of these transition metal-carbon mixed clusters, including the multicage SGP[2], the nanocrystal SGP[3], and the recent layered SGP[4]. Recording larger magic numbers will be of great help to test and distinguish between the various SGPs.

  1. Two and Two Make Zero: The Counting Numbers, Their Conceptualization, Symbolization, and Acquisition

    Science.gov (United States)

    Yaseen, H. S.

    2011-01-01

    "Two and Two Make Zero" considers children's acquisition of numerical concepts from a wide range of perspectives including topics that are often overlooked, most notably: the principal properties of the counting numbers in and of themselves; the role that numerical symbols play in number acquisition; the underlying conceptual structure of number…

  2. Determining the number of clusters for nuclei segmentation in breast cancer image

    Science.gov (United States)

    Fatichah, Chastine; Navastara, Dini Adni; Suciati, Nanik; Nuraini, Lubna

    2017-02-01

    Clustering is commonly technique for image segmentation, however determining an appropriate number of clusters is still challenging. Due to nuclei variation of size and shape in breast cancer image, an automatic determining number of clusters for segmenting the nuclei breast cancer is proposed. The phase of nuclei segmentation in breast cancer image are nuclei detection, touched nuclei detection, and touched nuclei separation. We use the Gram-Schmidt for nuclei cell detection, the geometry feature for touched nuclei detection, and combining of watershed and spatial k-Means clustering for separating the touched nuclei in breast cancer image. The spatial k-Means clustering is employed for separating the touched nuclei, however automatically determine the number of clusters is difficult due to the variation of size and shape of single cell breast cancer. To overcome this problem, first we apply watershed algorithm to separate the touched nuclei and then we calculate the distance among centroids in order to solve the over-segmentation. We merge two centroids that have the distance below threshold. And the new of number centroid as input to segment the nuclei cell using spatial k- Means algorithm. Experiment show that, the proposed scheme can improve the accuracy of nuclei cell counting.

  3. Galaxy Number Counts in the Subaru Deep Field Multi-band Analysis in a Hierarchical Galaxy Formation Model

    CERN Document Server

    Nagashima, M; Totani, T; Gouda, N

    2002-01-01

    Number counts of galaxies are re-analyzed using a semi-analytic model (SAM) of galaxy formation based on the hierarchical clustering scenario. Faint galaxies in the Subaru Deep Field (SDF) and the Hubble Deep Field (HDF) are compared with our model galaxies. We have determined the astrophysical parameters in the SAM that reproduce observations of nearby galaxies, and used them to predict the number counts and redshifts of faint galaxies for three cosmological models, the standard cold dark matter (CDM) universe, a flat lambda-CDM, and an open CDM. The novelty of our SAM analysis is the inclusion of selection effects arising from the cosmological dimming of surface brightness of high-z galaxies, and from the absorption of visible light by internal dust and intergalactic HI clouds. As was found in our previous work, in which the UV/optical HDF galaxies were compared with our model galaxies, we find that our SAM reproduces counts of near-IR SDF galaxies in low-density models, and that the standard CDM universe i...

  4. Fast distributed large-pixel-count hologram computation using a GPU cluster.

    Science.gov (United States)

    Pan, Yuechao; Xu, Xuewu; Liang, Xinan

    2013-09-10

    Large-pixel-count holograms are one essential part for big size holographic three-dimensional (3D) display, but the generation of such holograms is computationally demanding. In order to address this issue, we have built a graphics processing unit (GPU) cluster with 32.5 Tflop/s computing power and implemented distributed hologram computation on it with speed improvement techniques, such as shared memory on GPU, GPU level adaptive load balancing, and node level load distribution. Using these speed improvement techniques on the GPU cluster, we have achieved 71.4 times computation speed increase for 186M-pixel holograms. Furthermore, we have used the approaches of diffraction limits and subdivision of holograms to overcome the GPU memory limit in computing large-pixel-count holograms. 745M-pixel and 1.80G-pixel holograms were computed in 343 and 3326 s, respectively, for more than 2 million object points with RGB colors. Color 3D objects with 1.02M points were successfully reconstructed from 186M-pixel hologram computed in 8.82 s with all the above three speed improvement techniques. It is shown that distributed hologram computation using a GPU cluster is a promising approach to increase the computation speed of large-pixel-count holograms for large size holographic display.

  5. Everybody Counts, but Usually Just to 10! A Systematic Analysis of Number Representations in Children's Books

    Science.gov (United States)

    Powell, Sarah R.; Nurnberger-Haag, Julie

    2015-01-01

    Research Findings: Teachers and parents often use trade books to introduce or reinforce mathematics concepts. To date, an analysis of the early numeracy content of trade books has not been conducted. Consequently, this study evaluated the properties of numbers and counting within trade books. We coded 160 trade books targeted at establishing early…

  6. Everybody Counts, but Usually Just to 10! A Systematic Analysis of Number Representations in Children's Books

    Science.gov (United States)

    Powell, Sarah R.; Nurnberger-Haag, Julie

    2015-01-01

    Research Findings: Teachers and parents often use trade books to introduce or reinforce mathematics concepts. To date, an analysis of the early numeracy content of trade books has not been conducted. Consequently, this study evaluated the properties of numbers and counting within trade books. We coded 160 trade books targeted at establishing early…

  7. Planck 2015 results. XXIV. Cosmology from Sunyaev-Zeldovich cluster counts

    Science.gov (United States)

    Planck Collaboration; Ade, P. A. R.; Aghanim, N.; Arnaud, M.; Ashdown, M.; Aumont, J.; Baccigalupi, C.; Banday, A. J.; Barreiro, R. B.; Bartlett, J. G.; Bartolo, N.; Battaner, E.; Battye, R.; Benabed, K.; Benoît, A.; Benoit-Lévy, A.; Bernard, J.-P.; Bersanelli, M.; Bielewicz, P.; Bock, J. J.; Bonaldi, A.; Bonavera, L.; Bond, J. R.; Borrill, J.; Bouchet, F. R.; Bucher, M.; Burigana, C.; Butler, R. C.; Calabrese, E.; Cardoso, J.-F.; Catalano, A.; Challinor, A.; Chamballu, A.; Chary, R.-R.; Chiang, H. C.; Christensen, P. R.; Church, S.; Clements, D. L.; Colombi, S.; Colombo, L. P. L.; Combet, C.; Comis, B.; Couchot, F.; Coulais, A.; Crill, B. P.; Curto, A.; Cuttaia, F.; Danese, L.; Davies, R. D.; Davis, R. J.; de Bernardis, P.; de Rosa, A.; de Zotti, G.; Delabrouille, J.; Désert, F.-X.; Diego, J. M.; Dolag, K.; Dole, H.; Donzelli, S.; Doré, O.; Douspis, M.; Ducout, A.; Dupac, X.; Efstathiou, G.; Elsner, F.; Enßlin, T. A.; Eriksen, H. K.; Falgarone, E.; Fergusson, J.; Finelli, F.; Forni, O.; Frailis, M.; Fraisse, A. A.; Franceschi, E.; Frejsel, A.; Galeotta, S.; Galli, S.; Ganga, K.; Giard, M.; Giraud-Héraud, Y.; Gjerløw, E.; González-Nuevo, J.; Górski, K. M.; Gratton, S.; Gregorio, A.; Gruppuso, A.; Gudmundsson, J. E.; Hansen, F. K.; Hanson, D.; Harrison, D. L.; Henrot-Versillé, S.; Hernández-Monteagudo, C.; Herranz, D.; Hildebrandt, S. R.; Hivon, E.; Hobson, M.; Holmes, W. A.; Hornstrup, A.; Hovest, W.; Huffenberger, K. M.; Hurier, G.; Jaffe, A. H.; Jaffe, T. R.; Jones, W. C.; Juvela, M.; Keihänen, E.; Keskitalo, R.; Kisner, T. S.; Kneissl, R.; Knoche, J.; Kunz, M.; Kurki-Suonio, H.; Lagache, G.; Lähteenmäki, A.; Lamarre, J.-M.; Lasenby, A.; Lattanzi, M.; Lawrence, C. R.; Leonardi, R.; Lesgourgues, J.; Levrier, F.; Liguori, M.; Lilje, P. B.; Linden-Vørnle, M.; López-Caniego, M.; Lubin, P. M.; Macías-Pérez, J. F.; Maggio, G.; Maino, D.; Mandolesi, N.; Mangilli, A.; Maris, M.; Martin, P. G.; Martínez-González, E.; Masi, S.; Matarrese, S.; McGehee, P.; Meinhold, P. R.; Melchiorri, A.; Melin, J.-B.; Mendes, L.; Mennella, A.; Migliaccio, M.; Mitra, S.; Miville-Deschênes, M.-A.; Moneti, A.; Montier, L.; Morgante, G.; Mortlock, D.; Moss, A.; Munshi, D.; Murphy, J. A.; Naselsky, P.; Nati, F.; Natoli, P.; Netterfield, C. B.; Nørgaard-Nielsen, H. U.; Noviello, F.; Novikov, D.; Novikov, I.; Oxborrow, C. A.; Paci, F.; Pagano, L.; Pajot, F.; Paoletti, D.; Partridge, B.; Pasian, F.; Patanchon, G.; Pearson, T. J.; Perdereau, O.; Perotto, L.; Perrotta, F.; Pettorino, V.; Piacentini, F.; Piat, M.; Pierpaoli, E.; Pietrobon, D.; Plaszczynski, S.; Pointecouteau, E.; Polenta, G.; Popa, L.; Pratt, G. W.; Prézeau, G.; Prunet, S.; Puget, J.-L.; Rachen, J. P.; Rebolo, R.; Reinecke, M.; Remazeilles, M.; Renault, C.; Renzi, A.; Ristorcelli, I.; Rocha, G.; Roman, M.; Rosset, C.; Rossetti, M.; Roudier, G.; Rubiño-Martín, J. A.; Rusholme, B.; Sandri, M.; Santos, D.; Savelainen, M.; Savini, G.; Scott, D.; Seiffert, M. D.; Shellard, E. P. S.; Spencer, L. D.; Stolyarov, V.; Stompor, R.; Sudiwala, R.; Sunyaev, R.; Sutton, D.; Suur-Uski, A.-S.; Sygnet, J.-F.; Tauber, J. A.; Terenzi, L.; Toffolatti, L.; Tomasi, M.; Tristram, M.; Tucci, M.; Tuovinen, J.; Türler, M.; Umana, G.; Valenziano, L.; Valiviita, J.; Van Tent, B.; Vielva, P.; Villa, F.; Wade, L. A.; Wandelt, B. D.; Wehus, I. K.; Weller, J.; White, S. D. M.; Yvon, D.; Zacchei, A.; Zonca, A.

    2016-09-01

    We present cluster counts and corresponding cosmological constraints from the Planck full mission data set. Our catalogue consists of 439 clusters detected via their Sunyaev-Zeldovich (SZ) signal down to a signal-to-noise ratio of 6, and is more than a factor of 2 larger than the 2013 Planck cluster cosmology sample. The counts are consistent with those from 2013 and yield compatible constraints under the same modelling assumptions. Taking advantage of the larger catalogue, we extend our analysis to the two-dimensional distribution in redshift and signal-to-noise. We use mass estimates from two recent studies of gravitational lensing of background galaxies by Planck clusters to provide priors on the hydrostatic bias parameter, (1-b). In addition, we use lensing of cosmic microwave background (CMB) temperature fluctuations by Planck clusters as an independent constraint on this parameter. These various calibrations imply constraints on the present-day amplitude of matter fluctuations in varying degrees of tension with those from the Planck analysis of primary fluctuations in the CMB; for the lowest estimated values of (1-b) the tension is mild, only a little over one standard deviation, while it remains substantial (3.7σ) for the largest estimated value. We also examine constraints on extensions to the base flat ΛCDM model by combining the cluster and CMB constraints. The combination appears to favour non-minimal neutrino masses, but this possibility does little to relieve the overall tension because it simultaneously lowers the implied value of the Hubble parameter, thereby exacerbating the discrepancy with most current astrophysical estimates. Improving the precision of cluster mass calibrations from the current 10%-level to 1% would significantly strengthen these combined analyses and provide a stringent test of the base ΛCDM model.

  8. Some types of parent number talk count more than others: relations between parents' input and children's cardinal-number knowledge.

    Science.gov (United States)

    Gunderson, Elizabeth A; Levine, Susan C

    2011-09-01

    Before they enter preschool, children vary greatly in their numerical and mathematical knowledge, and this knowledge predicts their achievement throughout elementary school (e.g. Duncan et al., 2007; Ginsburg & Russell, 1981). Therefore, it is critical that we look to the home environment for parental inputs that may lead to these early variations. Recent work has shown that the amount of number talk that parents engage in with their children is robustly related to a critical aspect of mathematical development - cardinal-number knowledge (e.g. knowing that the word 'three' refers to sets of three entities; Levine, Suriyakham, Rowe, Huttenlocher & Gunderson, 2010). The present study characterizes the different types of number talk that parents produce and investigates which types are most predictive of children's later cardinal-number knowledge. We find that parents' number talk involving counting or labeling sets of present, visible objects is related to children's later cardinal-number knowledge, whereas other types of parent number talk are not. In addition, number talk that refers to large sets of present objects (i.e. sets of size 4 to 10 that fall outside children's ability to track individual objects) is more robustly predictive of children's later cardinal-number knowledge than talk about smaller sets. The relation between parents' number talk about large sets of present objects and children's cardinal-number knowledge remains significant even when controlling for factors such as parents' socioeconomic status and other measures of parents' number and non-number talk.

  9. Relationship between the CMB, SZ Cluster Counts, and Local Hubble Parameter Measurements in a Simple Void Model

    CERN Document Server

    Ichiki, Kiyotomo; Oguri, Masamune

    2015-01-01

    The discrepancy between the amplitudes of matter fluctuations inferred from Sunyaev-Zel'dovich (SZ) cluster number counts, the primary temperature, and the polarization anisotropies of the cosmic microwave background (CMB) measured by the Planck satellite can be reconciled if the local universe is embedded in an under-dense region as shown by Lee, 2014. Here using a simple void model assuming the open Friedmann-Robertson-Walker geometry and a Markov Chain Monte Carlo technique, we investigate how deep the local under-dense region needs to be to resolve this discrepancy. Such local void, if exists, predicts the local Hubble parameter value that is different from the global Hubble constant. We derive the posterior distribution of the local Hubble parameter from a joint fitting of the Planck CMB data and SZ cluster number counts assuming the simple void model. We show that the predicted local Hubble parameter value of $H_{\\rm loc}=70.1\\pm0.34~{\\rm km\\,s^{-1}Mpc^{-1}}$ is in better agreement with direct local Hub...

  10. The SCUBA-2 Cosmology Legacy Survey: 850 μm maps, catalogues and number counts

    Science.gov (United States)

    Geach, J. E.; Dunlop, J. S.; Halpern, M.; Smail, Ian; van der Werf, P.; Alexander, D. M.; Almaini, O.; Aretxaga, I.; Arumugam, V.; Asboth, V.; Banerji, M.; Beanlands, J.; Best, P. N.; Blain, A. W.; Birkinshaw, M.; Chapin, E. L.; Chapman, S. C.; Chen, C.-C.; Chrysostomou, A.; Clarke, C.; Clements, D. L.; Conselice, C.; Coppin, K. E. K.; Cowley, W. I.; Danielson, A. L. R.; Eales, S.; Edge, A. C.; Farrah, D.; Gibb, A.; Harrison, C. M.; Hine, N. K.; Hughes, D.; Ivison, R. J.; Jarvis, M.; Jenness, T.; Jones, S. F.; Karim, A.; Koprowski, M.; Knudsen, K. K.; Lacey, C. G.; Mackenzie, T.; Marsden, G.; McAlpine, K.; McMahon, R.; Meijerink, R.; Michałowski, M. J.; Oliver, S. J.; Page, M. J.; Peacock, J. A.; Rigopoulou, D.; Robson, E. I.; Roseboom, I.; Rotermund, K.; Scott, Douglas; Serjeant, S.; Simpson, C.; Simpson, J. M.; Smith, D. J. B.; Spaans, M.; Stanley, F.; Stevens, J. A.; Swinbank, A. M.; Targett, T.; Thomson, A. P.; Valiante, E.; Wake, D. A.; Webb, T. M. A.; Willott, C.; Zavala, J. A.; Zemcov, M.

    2017-02-01

    We present a catalogue of ˜3000 submillimetre sources detected (≥3.5σ) at 850 μm over ˜5 deg2 surveyed as part of the James Clerk Maxwell Telescope (JCMT) SCUBA-2 Cosmology Legacy Survey (S2CLS). This is the largest survey of its kind at 850 μm, increasing the sample size of 850 μm selected submillimetre galaxies by an order of magnitude. The wide 850 μm survey component of S2CLS covers the extragalactic fields: UKIDSS-UDS, COSMOS, Akari-NEP, Extended Groth Strip, Lockman Hole North, SSA22 and GOODS-North. The average 1σ depth of S2CLS is 1.2 mJy beam-1, approaching the SCUBA-2 850 μm confusion limit, which we determine to be σc ≈ 0.8 mJy beam-1. We measure the 850 μm number counts, reducing the Poisson errors on the differential counts to approximately 4 per cent at S850 ≈ 3 mJy. With several independent fields, we investigate field-to-field variance, finding that the number counts on 0.5°-1° scales are generally within 50 per cent of the S2CLS mean for S850 > 3 mJy, with scatter consistent with the Poisson and estimated cosmic variance uncertainties, although there is a marginal (2σ) density enhancement in GOODS-North. The observed counts are in reasonable agreement with recent phenomenological and semi-analytic models, although determining the shape of the faint-end slope (S850 10 mJy there are approximately 10 sources per square degree, and we detect the distinctive up-turn in the number counts indicative of the detection of local sources of 850 μm emission, and strongly lensed high-redshift galaxies. All calibrated maps and the catalogue are made publicly available.

  11. What counts in preschool number knowledge? A Bayes factor analytic approach toward theoretical model development.

    Science.gov (United States)

    Mou, Yi; Berteletti, Ilaria; Hyde, Daniel C

    2017-09-06

    Preschool children vary tremendously in their numerical knowledge, and these individual differences strongly predict later mathematics achievement. To better understand the sources of these individual differences, we measured a variety of cognitive and linguistic abilities motivated by previous literature to be important and then analyzed which combination of these variables best explained individual differences in actual number knowledge. Through various data-driven Bayesian model comparison and selection strategies on competing multiple regression models, our analyses identified five variables of unique importance to explaining individual differences in preschool children's symbolic number knowledge: knowledge of the count list, nonverbal approximate numerical ability, working memory, executive conflict processing, and knowledge of letters and words. Furthermore, our analyses revealed that knowledge of the count list, likely a proxy for explicit practice or experience with numbers, and nonverbal approximate numerical ability were much more important to explaining individual differences in number knowledge than general cognitive and language abilities. These findings suggest that children use a diverse set of number-specific, general cognitive, and language abilities to learn about symbolic numbers, but the contribution of number-specific abilities may overshadow that of more general cognitive abilities in the learning process. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. Magic Numbers for Classical Lennard-Jones Cluster Heat Capacities

    CERN Document Server

    Frantz, D D

    1994-01-01

    Heat capacity curves as functions of temperature for classical atomic clusters bound by pairwise Lennard-Jones potentials were calculated for aggregate sizes from 4 to 24 using Monte Carlo methods. J-walking (or jump-walking) was used to overcome convergence difficulties due to quasi-ergodicity in the solid-liquid transition region. The heat capacity curves were found to differ markedly and nonmonotonically as functions of cluster size. Curves for N = 4, 5 and 8 consisted of a smooth, featureless, monotonic increase throughout the transition region, while curves for N = 7 and 15-17 showed a distinct shoulder in this region; the remaining clusters had distinguishable transition heat capacity peaks. The size and location of these peaks exhibited "magic number" behavior, with the most pronounced peaks occurring for magic number sizes of N = 13, 19 and 23. A comparison of the heat capacities with other cluster properties in the solid-liquid transition region that have been reported in the literature indicates par...

  13. Cosmological Constraints from Galaxy Clustering and the Mass-to-Number Ratio of Galaxy Clusters

    CERN Document Server

    Tinker, Jeremy L; Wechsler, Risa H; Becker, Matthew R; Rozo, Eduardo; Zu, Ying; Weinberg, David H; Zehavi, Idit; Blanton, Michael; Busha, Michael; Koester, Benjamin P

    2011-01-01

    We place constraints on the average density (Omega_m) and clustering amplitude (sigma_8) of matter using a combination of two measurements from the Sloan Digital Sky Survey: the galaxy two-point correlation function, w_p, and the mass-to-galaxy-number ratio within galaxy clusters, M/N, analogous to cluster M/L ratios. Our w_p measurements are obtained from DR7 while the sample of clusters is the maxBCG sample, with cluster masses derived from weak gravitational lensing. We construct non-linear galaxy bias models using the Halo Occupation Distribution (HOD) to fit both w_p and M/N for different cosmological parameters. HOD models that match the same two-point clustering predict different numbers of galaxies in massive halos when Omega_m or sigma_8 is varied, thereby breaking the degeneracy between cosmology and bias. We demonstrate that this technique yields constraints that are consistent and competitive with current results from cluster abundance studies, even though this technique does not use abundance inf...

  14. Bayesian latent variable models for hierarchical clustered count outcomes with repeated measures in microbiome studies.

    Science.gov (United States)

    Xu, Lizhen; Paterson, Andrew D; Xu, Wei

    2017-04-01

    Motivated by the multivariate nature of microbiome data with hierarchical taxonomic clusters, counts that are often skewed and zero inflated, and repeated measures, we propose a Bayesian latent variable methodology to jointly model multiple operational taxonomic units within a single taxonomic cluster. This novel method can incorporate both negative binomial and zero-inflated negative binomial responses, and can account for serial and familial correlations. We develop a Markov chain Monte Carlo algorithm that is built on a data augmentation scheme using Pólya-Gamma random variables. Hierarchical centering and parameter expansion techniques are also used to improve the convergence of the Markov chain. We evaluate the performance of our proposed method through extensive simulations. We also apply our method to a human microbiome study.

  15. The upper bound of the optimal number of clusters in fuzzy clustering

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The upper bound of the optimal number of clusters in clustering algorithm is studied in this paper. A new method is proposed to solve this issue. This method shows that the rule cmax≤n, which is popular in current papers, is reasonable in some sense. The above conclusion is tested and analyzed by some typical examples in the literature, which demonstrates the validity of the new method.

  16. BLAST Observations of the South Ecliptic Pole field: Number Counts and Source Catalogs

    CERN Document Server

    Valiante, Elisabetta; Bock, James; Braglia, Filiberto; Chapin, Edward; Devlin, Mark Joseph; Griffin, Matthew; Gundersen, Joshua; Halpern, Mark; Hargrave, Peter; Hughes, David; Klein, Jeff; Marsden, Gaelen; Mauskopf, Philip; Netterfield, Calvin; Olmi, Luca; Pascale, Enzo; Patanchon, Guillaume; Rex, Marie; Scott, Douglas; Scott, Kimberly; Semisch, Christopher; Stabenau, Hans; Thomas, Nicholas; Truch, Matthew; Tucker, Carole; Tucker, Gregory; Viero, Marco; Wiebe, Donald

    2010-01-01

    We present results from a survey carried out by the Balloon-borne Large Aperture Submillimeter Telescope (BLAST) on a 9 deg^2 field near the South Ecliptic Pole at 250, 350 and 500 {\\mu}m. The median 1{\\sigma} depths of the maps are 36.0, 26.4 and 18.4 mJy, respectively. We apply a statistical method to estimate submillimeter galaxy number counts and find that they are in agreement with other measurements made with the same instrument and with the more recent results from Herschel/SPIRE. Thanks to the large field observed, the new measurements give additional constraints on the bright end of the counts. We identify 132, 89 and 61 sources with S/N>4 at 250, 350, 500 {\\mu}m, respectively and provide a multi-wavelength combined catalog of 232 sources. The new BLAST maps and catalogs are available publicly at http://blastexperiment.info.

  17. Design and Analysis Considerations for Cluster Randomized Controlled Trials That Have a Small Number of Clusters.

    Science.gov (United States)

    Deke, John

    2016-10-25

    Cluster randomized controlled trials (CRCTs) often require a large number of clusters in order to detect small effects with high probability. However, there are contexts where it may be possible to design a CRCT with a much smaller number of clusters (10 or fewer) and still detect meaningful effects. The objective is to offer recommendations for best practices in design and analysis for small CRCTs. I use simulations to examine alternative design and analysis approaches. Specifically, I examine (1) which analytic approaches control Type I errors at the desired rate, (2) which design and analytic approaches yield the most power, (3) what is the design effect of spurious correlations, and (4) examples of specific scenarios under which impacts of different sizes can be detected with high probability. I find that (1) mixed effects modeling and using Ordinary Least Squares (OLS) on data aggregated to the cluster level both control the Type I error rate, (2) randomization within blocks is always recommended, but how best to account for blocking through covariate adjustment depends on whether the precision gains offset the degrees of freedom loss, (3) power calculations can be accurate when design effects from small sample, spurious correlations are taken into account, and (4) it is very difficult to detect small effects with just four clusters, but with six or more clusters, there are realistic circumstances under which small effects can be detected with high probability. © The Author(s) 2016.

  18. The SCUBA 8-mJy survey - I Sub-millimetre maps, sources and number counts

    CERN Document Server

    Scott, S; Dunlop, J; Serjeant, S; Peacock, J; Ivison, R J; Oliver, S; Mann, R; Lawrence, A; Efstathiou, A; Rowan-Robinson, M; Hughes, D; Archibald, E; Blain, A W; Longair, M

    2002-01-01

    We present maps, source lists, and number counts from the largest, unbiassed, extragalactic sub-mm survey so far undertaken with the SCUBA camera on the JCMT. Our maps cover 260 sq. arcmin, to a noise level S(850)=2.5 mJy/beam. We have reduced the data using both SURF, and our own pipeline which produces zero-footprint maps and noise images. The uncorrelated noise maps produced by the latter approach have allowed application of a maximum-likelihood method to measure the statistical significance of each peak, leading to properly quantified flux-density errors for all potential sources. We detect 19 sources with S/N > 4, 38 with S/N > 3.5, and 72 with S/N > 3. To assess completeness and the impact of source confusion we have applied our source extraction algorithm to a series of simulated images. The result is a new estimate of the sub-mm source counts in the flux-density range S(850)=5-15mJy, which we compare with other estimates, and with model predictions. Our estimate of the cumulative source count at S(850...

  19. A distortion of very-high-redshift galaxy number counts by gravitational lensing.

    Science.gov (United States)

    Wyithe, J Stuart B; Yan, Haojing; Windhorst, Rogier A; Mao, Shude

    2011-01-13

    The observed number counts of high-redshift galaxy candidates have been used to build up a statistical description of star-forming activity at redshift z ≳ 7, when galaxies reionized the Universe. Standard models predict that a high incidence of gravitational lensing will probably distort measurements of flux and number of these earliest galaxies. The raw probability of this happening has been estimated to be ∼0.5 per cent (refs 11, 12), but can be larger owing to observational biases. Here we report that gravitational lensing is likely to dominate the observed properties of galaxies with redshifts of z ≳ 12, when the instrumental limiting magnitude is expected to be brighter than the characteristic magnitude of the galaxy sample. The number counts could be modified by an order of magnitude, with most galaxies being part of multiply imaged systems, located less than 1 arcsec from brighter foreground galaxies at z ≈ 2. This lens-induced association of high-redshift and foreground galaxies has perhaps already been observed among a sample of galaxy candidates identified at z ≈ 10.6. Future surveys will need to be designed to account for a significant gravitational lensing bias in high-redshift galaxy samples.

  20. Determination of cosmology and evolution from K-band magnitude-redshift and number count observations

    CERN Document Server

    Jackson, J C; Dodgson, Marina

    2002-01-01

    We determine cosmological and evolutionary parameters from the 3CR K-band Hubble diagram and K-band number counts, assuming that the galaxies in question undergo pure luminosity evolution. Separately the two data sets are highly degenerate with respect to choice of cosmological and evolutionary parameters, but in combination the degeneracy is resolved. Of models which are either flat or have $\\Omega_\\Lambda=0$, the preferred ones are close to the canonical case $\\Omega_\\CdM=1$, $\\Omega_\\Lambda=0$, with luminosity evolution amounting to one magnitude brighter at z=1.

  1. Corner contribution to percolation cluster numbers in three dimensions

    Science.gov (United States)

    Kovács, István A.; Iglói, Ferenc

    2014-05-01

    In three-dimensional critical percolation we study numerically the number of clusters NΓ which intersect a given subset of bonds Γ. If Γ represents the interface between a subsystem and the environment, then NΓ is related to the entanglement entropy of the critical diluted quantum Ising model. Due to corners in Γ there are singular corrections to NΓ, which scale as bΓlnLΓ, with LΓ being the linear size of Γ and the prefactor bΓ is found to be universal. This result indicates that logarithmic finite-size corrections exist in the free energy of three-dimensional critical systems.

  2. Three counting methods agree on cell and neuron number in chimpanzee primary visual cortex

    Directory of Open Access Journals (Sweden)

    Daniel James Miller

    2014-05-01

    Full Text Available Determining the cellular composition of specific brain regions is crucial to our understanding of the function of neurobiological systems. It is therefore useful to identify the extent to which different methods agree when estimating the same properties of brain circuitry. In this study, we estimated the number of neuronal and non-neuronal cells in the primary visual cortex (area 17 or V1 of both hemispheres from a single chimpanzee. Specifically, we processed samples distributed across V1 of the right hemisphere after cortex was flattened into a sheet using two variations of the isotropic fractionator cell and neuron counting method. We processed the left hemisphere as serial brain slices for stereological investigation. The goal of this study was to evaluate the agreement between these methods in the most direct manner possible by comparing estimates of cell density across one brain region of interest in a single individual. In our hands, these methods produced similar estimates of the total cellular population (approximately 1 billion as well as the number of neurons (approximately 675 million in chimpanzee V1, providing evidence that both techniques estimate the same parameters of interest. In addition, our results indicate the strengths of each distinct tissue preparation procedure, highlighting the importance of attention to anatomical detail. In summary, we found that the isotropic fractionator and the stereological optical fractionator produced concordant estimates of the cellular composition of V1, and that this result supports the conclusion that chimpanzees conform to the primate pattern of exceptionally high packing density in V1. Ultimately, our data suggest that investigators can optimize their experimental approach by using any of these counting methods to obtain reliable cell and neuron counts.

  3. Student Count Mechanisms for Funding Purposes. Education Policy Brief, Volume 10, Number 2, Spring 2012

    Science.gov (United States)

    Lara, Lindsi M.; Spradlin, Terry E.; Wodicka, Christopher Y.

    2012-01-01

    This Education Policy Brief provides an overview of the student count mechanisms that are currently employed by states. It then reviews Indiana's outgoing count mechanism, the Single Count Date, and compares it with the newly enacted Multiple Count Dates mechanism. To conclude the discussion, the brief examines how other states use the Multiple…

  4. A New Method for Measuring Weak Lensing Magnification With Weighted Number Counts

    CERN Document Server

    Gillis, Bryan

    2015-01-01

    We present a new local method for optimally estimating the local effects of magnification from weak gravitational lensing, using a comparison of number counts in an arbitrary region of space to the expected unmagnified number counts. This method has equivalent statistical power to the optimally-weighted correlation function method previously employed to measure magnification, but has the potential to be used for purposes such as mass mapping, and is also significantly computationally faster. We present a proof-of-principle test of this method on data from the CFHTLenS, showing that its calculated magnification signals agree with predictions from model fits to shear data. Finally, we investigate how magnification data can be used to supplement shear data in determining the best-fit model mass profiles for galaxy dark matter haloes. We find that at redshifts greater than z~0.6, the inclusion of magnification can often significantly improve the constraints on the components of the mass profile which relate to ga...

  5. What dot clusters and bar graphs reveal: subitizing is fast counting and subtraction.

    Science.gov (United States)

    Boles, David B; Phillips, Jeffrey B; Givens, Somer M

    2007-08-01

    In two studies, we found that dot enumeration tasks resulted in shallow-sloped response time (RT) functions for displays of 1-4 dots and steep-sloped functions for displays of 5-8 dots, replicating results implicating subitizing and counting processes for low and high ranges of dots, respectively. Extracting number from a specific type of bar graph within the same numerical range produced a shallow-sloped but scallop-shaped RT function. Factor analysis confirmed two independent subranges for dots, but all bar graph values defined a unitary factor. Significantly, factor scores and asymmetries both showed correlations of bar graph recognition to dot subitizing but not to dot counting, strongly suggesting that subitizing was used in both enumeration of low numbers of dots and bar graph recognition. According to these results, subitizing appears to be a nonverbal process operating flexibly in either additive or subtractive fashion on analog quantities having spatial extent, a conclusion consistent with a fast-counting model of subitizing but not with other models of the subitizing process.

  6. The SCUBA-2 Cosmology Legacy Survey: 850um maps, catalogues and number counts

    CERN Document Server

    Geach, J E; Halpern, M; Smail, Ian; van der Werf, P; Alexander, D M; Almaini, O; Aretxaga, I; Arumugam, V; Asboth, V; Banerji, M; Beanlands, J; Best, P N; Blain, A W; Birkinshaw, M; Chapin, E L; Chapman, S C; Chen, C-C; Chrysostomou, A; Clarke, C; Clements, D L; Conselice, C; Coppin, K E K; Cowley, W I; Danielson, A L R; Eales, S; Edge, A C; Farrah, D; Gibb, A; Harrison, C M; Hine, N K; Hughes, D; Ivison, R J; Jarvis, M; Jenness, T; Jones, S F; Karim, A; Koprowski, M; Knudsen, K K; Lacey, C G; Mackenzie, T; Marsden, G; McAlpine, K; McMahon, R; Meijerink, R; Michalowski, M J; Oliver, S J; Page, M J; Peacock, J A; Rigopoulou, D; Robson, E I; Roseboom, I; Rotermund, K; Scott, Douglas; Serjeant, S; Simpson, C; Simpson, J M; Smith, D J B; Spaans, M; Stanley, F; Stevens, J A; Swinbank, A M; Targett, T; Thomson, A P; Valiante, E; Webb, T M A; Willott, C; Zavala, J A; Zemcov, M

    2016-01-01

    We present a catalogue of nearly 3,000 submillimetre sources detected at 850um over ~5 square degrees surveyed as part of the James Clerk Maxwell Telescope (JCMT) SCUBA-2 Cosmology Legacy Survey (S2CLS). This is the largest survey of its kind at 850um, probing a meaningful cosmic volume at the peak of star formation activity and increasing the sample size of submillimetre galaxies selected at 850um by an order of magnitude. We describe the wide 850um survey component of S2CLS, which covers the key extragalactic survey fields: UKIDSS-UDS, COSMOS, Akari-NEP, Extended Groth Strip, Lockman Hole North, SSA22 and GOODS-North. The average 1-sigma depth of S2CLS is 1.2 mJy/beam, approaching the SCUBA-2 850um confusion limit, which we determine to be ~0.8 mJy/beam. We measure the single dish 850um number counts to unprecedented accuracy, reducing the Poisson errors on the differential counts to approximately 4% at S_850~3mJy. With several independent fields, we investigate field-to-field variance, finding that the num...

  7. Expected z>5 QSO number counts in large area deep near-infrared surveys

    CERN Document Server

    Fontanot, Fabio; Jester, Sebastian

    2007-01-01

    The QSO luminosity function at z>5 provides strong constraints on models of joint evolution of QSO and their hosts. However, these observations are challenging because the low space densities of these objects necessitate surveying of large areas, in order to obtain statistically meaningful samples, while at the same time cosmological redshifting and dimming means that rather deep Near Infrared (NIR) imaging must be carried out. Several upcoming and proposed facilities with wide-field NIR imaging capabilities will open up this new region of parameter space. In this paper we present predictions for the expected number counts of z>5 QSOs, based on simple empirical models of QSO evolution, as a function of redshift, depth and surveyed area. We compute the evolution of observed-frame QSO magnitudes and colors in a representative photometric system covering the wavelength range 550nm < \\lambda < 1800nm, and combine this information with different estimates for the evolution of the QSO luminosity function. We ...

  8. ALMA Deep Field in SSA22: Source Catalog and Number Counts

    Science.gov (United States)

    Umehata, Hideki; Tamura, Yoichi; Kohno, Kotaro; Ivison, R. J.; Smail, Ian; Hatsukade, Bunyo; Nakanishi, Kouichiro; Kato, Yuta; Ikarashi, Soh; Matsuda, Yuichi; Fujimoto, Seiji; Iono, Daisuke; Lee, Minju; Steidel, Charles C.; Saito, Tomoki; Alexander, D. M.; Yun, Min S.; Kubo, Mariko

    2017-01-01

    We present results from a deep 2‧ × 3‧ (comoving scale of 3.7 Mpc × 5.5 Mpc at z = 3) survey at 1.1 mm, taken with the Atacama Large Millimeter/submillimeter Array (ALMA) in the SSA22 field. We observe the core region of a z = 3.09 protocluster, achieving a typical rms sensitivity of 60 μJy beam‑1 at a spatial resolution of 0.″7. We detect 18 robust ALMA sources at a signal-to-noise ratio (S/N) > 5. Comparison between the ALMA map and a 1.1 mm map, taken with the AzTEC camera on the Atacama Submillimeter Telescope Experiment (ASTE), indicates that three submillimeter sources discovered by the AzTEC/ASTE survey are resolved into eight individual submillimeter galaxies (SMGs) by ALMA. At least 10 of our 18 ALMA SMGs have spectroscopic redshifts of z ≃ 3.09, placing them in the protocluster. This shows that a number of dusty starburst galaxies are forming simultaneously in the core of the protocluster. The nine brightest ALMA SMGs with S/N > 10 have a median intrinsic angular size of 0\\buildrel{\\prime\\prime}\\over{.} {32}-0.06+0.13 ({2.4}-0.4+1.0 physical kpc at z = 3.09), which is consistent with previous size measurements of SMGs in other fields. As expected, the source counts show a possible excess compared to the counts in the general fields at S1.1mm ≥ 1.0 mJy, due to the protocluster. Our contiguous mm mapping highlights the importance of large-scale structures on the formation of dusty starburst galaxies.

  9. Making stillbirths count, making numbers talk - Issues in data collection for stillbirths

    NARCIS (Netherlands)

    Froen, J. Frederik; Gordijn, Sanne J.; Abdel-Aleem, Hany; Bergsjo, Per; Betran, Ana; Duke, Charles W.; Fauveau, Vincent; Flenady, Vicki; Hinderaker, Sven Gudmund; Hofmeyr, G. Justus; Jokhio, Abdul Hakeem; Lawn, Joy; Lumbiganon, Pisake; Merialdi, Mario; Pattinson, Robert; Shankar, Anuraj

    2009-01-01

    Background: Stillbirths need to count. They constitute the majority of the world's perinatal deaths and yet, they are largely invisible. Simply counting stillbirths is only the first step in analysis and prevention. From a public health perspective, there is a need for information on timing and

  10. Combined Mapping of Multiple clUsteriNg ALgorithms (COMMUNAL): A Robust Method for Selection of Cluster Number, K.

    Science.gov (United States)

    Sweeney, Timothy E; Chen, Albert C; Gevaert, Olivier

    2015-11-19

    In order to discover new subsets (clusters) of a data set, researchers often use algorithms that perform unsupervised clustering, namely, the algorithmic separation of a dataset into some number of distinct clusters. Deciding whether a particular separation (or number of clusters, K) is correct is a sort of 'dark art', with multiple techniques available for assessing the validity of unsupervised clustering algorithms. Here, we present a new technique for unsupervised clustering that uses multiple clustering algorithms, multiple validity metrics, and progressively bigger subsets of the data to produce an intuitive 3D map of cluster stability that can help determine the optimal number of clusters in a data set, a technique we call COmbined Mapping of Multiple clUsteriNg ALgorithms (COMMUNAL). COMMUNAL locally optimizes algorithms and validity measures for the data being used. We show its application to simulated data with a known K, and then apply this technique to several well-known cancer gene expression datasets, showing that COMMUNAL provides new insights into clustering behavior and stability in all tested cases. COMMUNAL is shown to be a useful tool for determining K in complex biological datasets, and is freely available as a package for R.

  11. Table of Cluster and Organism Species Number - Gclust Server | LSDB Archive [Life Science Database Archive metadata

    Lifescience Database Archive (English)

    Full Text Available Gclust Server Table of Cluster and Organism Species Number Data detail Data name Table of Cluster and Organism Specie...he number of sequences contained in the cluster, organism species, the number of ...sequences belonging to the cluster for each of 95 organism species, compiled into a tab-delimited text file ...format table. Data file File name: all95.tbl.zip File URL: ftp://ftp.biosciencedbc.jp/archive/gclust/LATEST/...er of sequences belonging to cluster in the Agrobacterium tumefaciens str. C58 sequence Bja Number of sequen

  12. A Self-Adaptive Fuzzy c-Means Algorithm for Determining the Optimal Number of Clusters

    Science.gov (United States)

    Wang, Zhihao; Yi, Jing

    2016-01-01

    For the shortcoming of fuzzy c-means algorithm (FCM) needing to know the number of clusters in advance, this paper proposed a new self-adaptive method to determine the optimal number of clusters. Firstly, a density-based algorithm was put forward. The algorithm, according to the characteristics of the dataset, automatically determined the possible maximum number of clusters instead of using the empirical rule n and obtained the optimal initial cluster centroids, improving the limitation of FCM that randomly selected cluster centroids lead the convergence result to the local minimum. Secondly, this paper, by introducing a penalty function, proposed a new fuzzy clustering validity index based on fuzzy compactness and separation, which ensured that when the number of clusters verged on that of objects in the dataset, the value of clustering validity index did not monotonically decrease and was close to zero, so that the optimal number of clusters lost robustness and decision function. Then, based on these studies, a self-adaptive FCM algorithm was put forward to estimate the optimal number of clusters by the iterative trial-and-error process. At last, experiments were done on the UCI, KDD Cup 1999, and synthetic datasets, which showed that the method not only effectively determined the optimal number of clusters, but also reduced the iteration of FCM with the stable clustering result. PMID:28042291

  13. New technique to count mosquito adults: using ImageJ software to estimate number of mosquito adults in a trap.

    Science.gov (United States)

    Kesavaraju, Banugopan; Dickson, Sammie

    2012-12-01

    A new technique is described here to count mosquitoes using open-source software. We wanted to develop a protocol that would estimate the total number of mosquitoes from a picture using ImageJ. Adult mosquitoes from CO2-baited traps were spread on a tray and photographed. The total number of mosquitoes in a picture was estimated using various calibrations on ImageJ, and results were compared with manual counting to identify the ideal calibration. The average trap count was 1,541, and the average difference between the manual count and the best calibration was 174.11 +/- 21.59, with 93% correlation. Subsequently, contents of a trap were photographed 5 different times after they were shuffled between each picture to alter the picture pattern of adult mosquitoes. The standard error among variations stayed below 50, indicating limited variation for total count between pictures of the same trap when the pictures were processed through ImageJ. These results indicate the software could be utilized efficiently to estimate total number of mosquitoes from traps.

  14. Rhythm in number: exploring the affective, social and mathematical dimensions of using TouchCounts

    Science.gov (United States)

    Sinclair, Nathalie; Chorney, Sean; Rodney, Sheree

    2016-03-01

    In this paper, we investigate the mathematical, social and affective nature of children's engagement with TouchCounts, a multitouch application for counting and doing arithmetic. In order to study these dimensions of engagement in a way that recognizes their fundamental intertwinement, we use rhythm as a primary unit of analysis. Drawing on over 8 hours of research sessions with children aged 6, 7 and 8 years old, we show how various rhythms emerged from their interactions and how these rhythms changed over time—moving from the particular to the more general. We also show how important rhythm is to children's carrying of activity, which relates to aspects of interest and motivation.

  15. The State of the World's Children 2014 in Numbers: Every Child Counts. Revealing Disparities, Advancing Children's Rights

    Science.gov (United States)

    Aslam, Abid; Grojec, Anna; Little, Céline; Maloney, Ticiana; Tamagni, Jordan

    2014-01-01

    "The State of the World's Children 2014 In Numbers: Every Child Counts" highlights the critical role data and monitoring play in realizing children's rights. Credible data, disseminated effectively and used correctly, make it possible to target interventions that help right the wrong of exclusion. Data do not, of themselves, change the…

  16. Variation in number of trunk vertebrae and in count of costal grooves in salamanders of the family Hynobiidae

    NARCIS (Netherlands)

    Litvinchuk, S.N.; Borkin, L.J.

    2003-01-01

    Ten species from five genera of the family Hynobiidae were studied. The number of trunk vertebrae varied between 14 and 21, and the count of costal grooves ranged from 10 to 15. Both the within-species variation and the within-population variation were recorded in some species. In both kinds the val

  17. Effect of pre-milking teat preparation procedures on the microbial count on teats prior to cluster application

    Directory of Open Access Journals (Sweden)

    Gleeson D

    2009-07-01

    Full Text Available Abstract A study was carried out to investigate the effect of six pre-milking teat preparation procedures on lowering the staphylococal, streptococcal and coliform microbial count on teat skin prior to cluster application. The teat preparations included 'Iodine', 'Chlorhexidine' teat foam, 'Washing and drying' with paper, 'No preparation', 'Chlorine' teat foam, and disinfectant 'Wipes'. Teat preparations were applied for five days to 10 cows for each treatment during two herd management periods (indoors and outdoors. Teats were swabbed on day four and five before teat preparation and repeated after teat preparation. The swabs were plated on three selective agars: Baird Parker (Staphylococcus spp., Edwards (Streptococcus spp., and MacConkey (coliform. Following incubation, microbial counts for each pathogen type were manually counted and assigned to one of six categories depending on the microbial counts measured. The results were analysed by logistic regression using SAS 28. The main analysis was conducted on binary improvement scores for the swabbing outcomes. There were no differences for staphylococcal, streptococcal and coliform bacterial counts between treatments, measured 'before' teat preparation. Treatments containing 'Chlorhexidine' teat foam (OR = 4.46 and 'Wipes' (OR = 4.46 resulted in a significant reduction (P

  18. Clustering large number of extragalactic spectra of galaxies and quasars through canopies

    CERN Document Server

    De, Tuli; Chattopadhyay, Asis Kumar

    2013-01-01

    Cluster analysis is the distribution of objects into different groups or more precisely the partitioning of a data set into subsets (clusters) so that the data in subsets share some common trait according to some distance measure. Unlike classi cation, in clustering one has to rst decide the optimum number of clusters and then assign the objects into different clusters. Solution of such problems for a large number of high dimensional data points is quite complicated and most of the existing algorithms will not perform properly. In the present work a new clustering technique applicable to large data set has been used to cluster the spectra of 702248 galaxies and quasars having 1540 points in wavelength range imposed by the instrument. The proposed technique has successfully discovered ve clusters from this 702248X1540 data matrix.

  19. Deep near-IR observations of the Chandra Deep Field and of the HDF-South - Color and Number Counts

    CERN Document Server

    Saracco, P; Cristiani, S; D'Odorico, S; Fontana, A; Iovino, A; Poli, F; Vanzella, E

    2001-01-01

    We present near-IR (J and Ks) number counts and colors of galaxies detected in deep VLT-ISAAC images centered on the Chandra Deep Field and Hubble Deep Field-South for a total area of 13.6 arcmin$^2$. The limiting surface brightness obtained is Ks$\\simeq$22.8 mag/arcsec$^2$ and J$\\simeq$24.5 (1$\\sigma$) on both fields. A d$log$N/dm relation with a slope of $\\sim0.34$ in J and $\\sim0.28$ in Ks is found in both fields with no evidence of decline near the magnitude limit. The median J-Ks color of galaxies becomes bluer at magnitudes fainter than Ks$\\sim18$, in agreement with the different number counts slope observed in the two bands. We find a fraction ($\\le5%$ of the total sample) of sources with color redder than J-Ks=2.3 at magnitudes Ks$>20$. Most of them appear as isolated sources, possibly elliptical or dusty starburst galaxies at redshift $z>2$. The comparison of the observed number counts with models shows that our J-band and Ks-band counts are consistent with the prediction of a model based on a small ...

  20. Magic Numbers in Molecular Clusters: A Probe for Chemical Reactivity

    Science.gov (United States)

    1992-05-29

    gas phase reactions of DME with DME + or any of its frag- ment ions giving rise to methanol ions. The reaction (s) giving rise to the { DME )nCH 3 OH 2... methanol to give DME but to date, the mechanism of the initial C-C bond formation remains to be unequivocally established. 2 0 The initial step of...in proto- nated cluster ions. Several ion/molecule reactions in the DME system have been reported in 10 which methanol was suggested as the neutral

  1. A new method for determining the sensitivity of X-ray imaging observations and the X-ray number counts

    CERN Document Server

    Georgakakis, A; Laird, E S; Aird, J; Trichas, M

    2008-01-01

    We present a new method for determining the sensitivity of X-ray imaging observations, which correctly accounts for the observational biases that affect the probability of detecting a source of a given X-ray flux, without the need to perform a large number of time consuming simulations. We use this new technique to estimate the X-ray source counts in different spectral bands (0.5-2, 0.5-10, 2-10 and 5-10keV) by combining deep pencil-beam and shallow wide-area Chandra observations. The sample has a total of 6295 unique sources over an area of $\\rm 11.8deg^2$ and is the largest used to date to determine the X-ray number counts. We determine, for the first time, the break flux in the 5-10 keV band, in the case of a double power-law source count distribution. We also find an upturn in the 0.5-2keV counts at fluxes below about 6e-17erg/s/cm2. We show that this can be explained by the emergence of normal star-forming galaxies which dominate the X-ray population at faint fluxes. The fraction of the diffuse X-ray bac...

  2. The statistical distribution of the number of counted scintillation photons in digital silicon photomultipliers: model and validation.

    Science.gov (United States)

    van Dam, Herman T; Seifert, Stefan; Schaart, Dennis R

    2012-08-07

    In the design and application of scintillation detectors based on silicon photomultipliers (SiPMs), e.g. in positron emission tomography imaging, it is important to understand and quantify the non-proportionality of the SiPM response due to saturation, crosstalk and dark counts. A new type of SiPM, the so-called digital silicon photomultiplier (dSiPM), has recently been introduced. Here, we develop a model of the probability distribution of the number of fired microcells, i.e. the number of counted scintillation photons, in response to a given amount of energy deposited in a scintillator optically coupled to a dSiPM. Based on physical and functional principles, the model elucidates the statistical behavior of dSiPMs. The model takes into account the photon detection efficiency of the detector; the light yield, excess variance and time profile of the scintillator; and the crosstalk probability, dark count rate, integration time and the number of microcells of the dSiPM. Furthermore, relations for the expectation value and the variance of the number of fired cells are deduced. These relations are applied in the experimental validation of the model using a dSiPM coupled to a LSO:Ce,Ca scintillator. Finally, we propose an accurate method for the correction of energy spectra measured with dSiPM-based scintillation detectors.

  3. Making stillbirths count, making numbers talk - Issues in data collection for stillbirths

    Directory of Open Access Journals (Sweden)

    Jokhio Abdul

    2009-12-01

    Full Text Available Abstract Background Stillbirths need to count. They constitute the majority of the world's perinatal deaths and yet, they are largely invisible. Simply counting stillbirths is only the first step in analysis and prevention. From a public health perspective, there is a need for information on timing and circumstances of death, associated conditions and underlying causes, and availability and quality of care. This information will guide efforts to prevent stillbirths and improve quality of care. Discussion In this report, we assess how different definitions and limits in registration affect data capture, and we discuss the specific challenges of stillbirth registration, with emphasis on implementation. We identify what data need to be captured, we suggest a dataset to cover core needs in registration and analysis of the different categories of stillbirths with causes and quality indicators, and we illustrate the experience in stillbirth registration from different cultural settings. Finally, we point out gaps that need attention in the International Classification of Diseases and review the qualities of alternative systems that have been tested in low- and middle-income settings. Summary Obtaining high-quality data will require consistent definitions for stillbirths, systematic population-based registration, better tools for surveys and verbal autopsies, capacity building and training in procedures to identify causes of death, locally adapted quality indicators, improved classification systems, and effective registration and reporting systems.

  4. On Counting the Number of Non-isomorphic Bipartite Graphs%非同构二部图的计数

    Institute of Scientific and Technical Information of China (English)

    徐尚进; 吴正飞; 朱雁

    2006-01-01

    该文研究的是[m,n]型二部图的计数问题,利用这类图连接矩阵的分类导出了一种组合计数方法.%A combinatoric method which counts the number of non-isomorphic bi-partite graphs with type[m,n]is obtained by classifying their connection matrices.

  5. Planck 2015 results: XXIV. Cosmology from Sunyaev-Zeldovich cluster counts

    DEFF Research Database (Denmark)

    Ade, P. A R; Aghanim, N.; Arnaud, M.;

    2016-01-01

    because it simultaneously lowers the implied value of the Hubble parameter, thereby exacerbating the discrepancy with most current astrophysical estimates. Improving the precision of cluster mass calibrations from the current 10%-level to 1% would significantly strengthen these combined analyses...

  6. Sputum neutrophil counts are associated with more severe asthma phenotypes using cluster analysis.

    Science.gov (United States)

    Moore, Wendy C; Hastie, Annette T; Li, Xingnan; Li, Huashi; Busse, William W; Jarjour, Nizar N; Wenzel, Sally E; Peters, Stephen P; Meyers, Deborah A; Bleecker, Eugene R

    2014-06-01

    Clinical cluster analysis from the Severe Asthma Research Program (SARP) identified 5 asthma subphenotypes that represent the severity spectrum of early-onset allergic asthma, late-onset severe asthma, and severe asthma with chronic obstructive pulmonary disease characteristics. Analysis of induced sputum from a subset of SARP subjects showed 4 sputum inflammatory cellular patterns. Subjects with concurrent increases in eosinophil (≥2%) and neutrophil (≥40%) percentages had characteristics of very severe asthma. To better understand interactions between inflammation and clinical subphenotypes, we integrated inflammatory cellular measures and clinical variables in a new cluster analysis. Participants in SARP who underwent sputum induction at 3 clinical sites were included in this analysis (n = 423). Fifteen variables, including clinical characteristics and blood and sputum inflammatory cell assessments, were selected using factor analysis for unsupervised cluster analysis. Four phenotypic clusters were identified. Cluster A (n = 132) and B (n = 127) subjects had mild-to-moderate early-onset allergic asthma with paucigranulocytic or eosinophilic sputum inflammatory cell patterns. In contrast, these inflammatory patterns were present in only 7% of cluster C (n = 117) and D (n = 47) subjects who had moderate-to-severe asthma with frequent health care use despite treatment with high doses of inhaled or oral corticosteroids and, in cluster D, reduced lung function. The majority of these subjects (>83%) had sputum neutrophilia either alone or with concurrent sputum eosinophilia. Baseline lung function and sputum neutrophil percentages were the most important variables determining cluster assignment. This multivariate approach identified 4 asthma subphenotypes representing the severity spectrum from mild-to-moderate allergic asthma with minimal or eosinophil-predominant sputum inflammation to moderate-to-severe asthma with neutrophil-predominant or mixed granulocytic

  7. Effect of pre-milking teat preparation procedures on the microbial count on teats prior to cluster application

    Science.gov (United States)

    2009-01-01

    A study was carried out to investigate the effect of six pre-milking teat preparation procedures on lowering the staphylococal, streptococcal and coliform microbial count on teat skin prior to cluster application. The teat preparations included 'Iodine', 'Chlorhexidine' teat foam, 'Washing and drying' with paper, 'No preparation', 'Chlorine' teat foam, and disinfectant 'Wipes'. Teat preparations were applied for five days to 10 cows for each treatment during two herd management periods (indoors and outdoors). Teats were swabbed on day four and five before teat preparation and repeated after teat preparation. The swabs were plated on three selective agars: Baird Parker (Staphylococcus spp.), Edwards (Streptococcus spp.), and MacConkey (coliform). Following incubation, microbial counts for each pathogen type were manually counted and assigned to one of six categories depending on the microbial counts measured. The results were analysed by logistic regression using SAS [28]. The main analysis was conducted on binary improvement scores for the swabbing outcomes. There were no differences for staphylococcal, streptococcal and coliform bacterial counts between treatments, measured 'before' teat preparation. Treatments containing 'Chlorhexidine' teat foam (OR = 4.46) and 'Wipes' (OR = 4.46) resulted in a significant reduction (P teats compared to 'Washing and drying' or 'No preparation'. 'Chlorine' teat foam (OR = 3.45) and 'Wipes' (3.45) had the highest probability (P disinfectant treatments applied in reducing coliforms. Thus, the use of some disinfectant products for pre-milking teat preparation can have beneficial effects on reducing the levels of staphylococcal and streptococcal pathogens on teat skin. PMID:21851738

  8. Determining the Number of Clusters in a Data Set Without Graphical Interpretation

    Science.gov (United States)

    Aguirre, Nathan S.; Davies, Misty D.

    2011-01-01

    Cluster analysis is a data mining technique that is meant ot simplify the process of classifying data points. The basic clustering process requires an input of data points and the number of clusters wanted. The clustering algorithm will then pick starting C points for the clusters, which can be either random spatial points or random data points. It then assigns each data point to the nearest C point where "nearest usually means Euclidean distance, but some algorithms use another criterion. The next step is determining whether the clustering arrangement this found is within a certain tolerance. If it falls within this tolerance, the process ends. Otherwise the C points are adjusted based on how many data points are in each cluster, and the steps repeat until the algorithm converges,

  9. The irrationals a story of the numbers you can't count on

    CERN Document Server

    Havil, Julian

    2012-01-01

    The ancient Greeks discovered them, but it wasn’t until the nineteenth century that irrational numbers were properly understood and rigorously defined, and even today not all their mysteries have been revealed. In The Irrationals, the first popular and comprehensive book on the subject, Julian Havil tells the story of irrational numbers and the mathematicians who have tackled their challenges, from antiquity to the twenty-first century. Along the way, he explains why irrational numbers are surprisingly difficult to define—and why so many questions still surround them. Fascinating and illuminating, this is a book for everyone who loves math and the history behind it.

  10. AutoSOME: a clustering method for identifying gene expression modules without prior knowledge of cluster number

    Directory of Open Access Journals (Sweden)

    Cooper James B

    2010-03-01

    Full Text Available Abstract Background Clustering the information content of large high-dimensional gene expression datasets has widespread application in "omics" biology. Unfortunately, the underlying structure of these natural datasets is often fuzzy, and the computational identification of data clusters generally requires knowledge about cluster number and geometry. Results We integrated strategies from machine learning, cartography, and graph theory into a new informatics method for automatically clustering self-organizing map ensembles of high-dimensional data. Our new method, called AutoSOME, readily identifies discrete and fuzzy data clusters without prior knowledge of cluster number or structure in diverse datasets including whole genome microarray data. Visualization of AutoSOME output using network diagrams and differential heat maps reveals unexpected variation among well-characterized cancer cell lines. Co-expression analysis of data from human embryonic and induced pluripotent stem cells using AutoSOME identifies >3400 up-regulated genes associated with pluripotency, and indicates that a recently identified protein-protein interaction network characterizing pluripotency was underestimated by a factor of four. Conclusions By effectively extracting important information from high-dimensional microarray data without prior knowledge or the need for data filtration, AutoSOME can yield systems-level insights from whole genome microarray expression studies. Due to its generality, this new method should also have practical utility for a variety of data-intensive applications, including the results of deep sequencing experiments. AutoSOME is available for download at http://jimcooperlab.mcdb.ucsb.edu/autosome.

  11. [Method for an absolute count of the number of parasitic protozoa in fish].

    Science.gov (United States)

    Sous', S M

    1976-01-01

    A new technique is given of the absolute calculation of parasitic Protozoa in fishes. The mucus from the body and gills of fishes was mixed with such volume of water (V) that the drop of mixture (v) was clearly seen under themicroscope. The calculation of Protozoa was done in a sample from three drops of mixture covered with three slides (S). From 50 to 100 viewing fields were seen the them and an average number of Protozoa in one field was calculated. The total number of Protozoa in one fish (N) was equal to an average number of parasites in a viewing field (n) multiplied by the total number of viewing fields (m) which could be obtained at the examination of the whole mixture. The latter was calculated conventionally (see articles).

  12. The XMM Cluster Survey: The Halo Occupation Number of BOSS galaxies in X-ray clusters

    CERN Document Server

    Mehrtens, Nicola; Nichol, Robert C; Collins, Chris A; Sahlen, Martin; Rooney, Philip J; Mayers, Julian A; Bermeo-Hernandez, A; Bristow, Martyn; Capozzi, Diego; Christodoulou, L; Comparat, Johan; Hilton, Matt; Hoyle, Ben; Kay, Scott T; Liddle, Andrew R; Mann, Robert G; Masters, Karen; Miller, Christopher J; Parejko, John K; Prada, Francisco; Ross, Ashley J; Schneider, Donald P; Stott, John P; Streblyanska, Alina; Viana, Pedro T P; White, Martin; Wilcox, Harry; Zehavi, Idit

    2015-01-01

    We present a direct measurement of the mean halo occupation distribution (HOD) of galaxies taken from the eleventh data release (DR11) of the Sloan Digital Sky Survey-III Baryon Acoustic Oscillation Survey (BOSS). The HOD of BOSS low-redshift (LOWZ: $0.2 < z < 0.4$) and Constant-Mass (CMASS: $0.43 clusters drawn from the XMM Cluster Survey (XCS). Halo masses are determined for each galaxy cluster based on X-ray temperature measurements, and range between ${\\rm log_{10}} (M_{180}/M_{\\odot}) = 13-15$, encompassing the mass range of the `one-halo' term. Our directly-measured HODs are consistent with the HOD-model fits inferred via the galaxy-clustering analyses of Parejko et al. (2013) for the BOSS LOWZ sample and White et al. (2011) for the BOSS CMASS sample. We determine a best-fit alpha-index of 0.91$\\pm$0.08 and $1.27^{+0.03}_{-0.04}$ for the CMASS and LOWZ HOD, respectively. This result p...

  13. The XMM Cluster Survey: the halo occupation number of BOSS galaxies in X-ray clusters

    Science.gov (United States)

    Mehrtens, Nicola; Romer, A. Kathy; Nichol, Robert C.; Collins, Chris A.; Sahlén, Martin; Rooney, Philip J.; Mayers, Julian A.; Bermeo-Hernandez, A.; Bristow, Martyn; Capozzi, Diego; Christodoulou, L.; Comparat, Johan; Hilton, Matt; Hoyle, Ben; Kay, Scott T.; Liddle, Andrew R.; Mann, Robert G.; Masters, Karen; Miller, Christopher J.; Parejko, John K.; Prada, Francisco; Ross, Ashley J.; Schneider, Donald P.; Stott, John P.; Streblyanska, Alina; Viana, Pedro T. P.; White, Martin; Wilcox, Harry; Zehavi, Idit

    2016-12-01

    We present a direct measurement of the mean halo occupation distribution (HOD) of galaxies taken from the eleventh data release (DR11) of the Sloan Digital Sky Survey-III Baryon Oscillation Spectroscopic Survey (BOSS). The HOD of BOSS low-redshift (LOWZ: 0.2 < z < 0.4) and Constant-Mass (CMASS: 0.43 < z < 0.7) galaxies is inferred via their association with the dark matter haloes of 174 X-ray-selected galaxy clusters drawn from the XMM Cluster Survey (XCS). Halo masses are determined for each galaxy cluster based on X-ray temperature measurements, and range between log10(M180/M⊙) = 13 and 15. Our directly measured HODs are consistent with the HOD-model fits inferred via the galaxy-clustering analyses of Parejko et al. for the BOSS LOWZ sample and White et al. for the BOSS CMASS sample. Under the simplifying assumption that the other parameters that describe the HOD hold the values measured by these authors, we have determined a best-fitting alpha-index of 0.91 ± 0.08 and 1.27^{+0.03}_{-0.04} for the CMASS and LOWZ HOD, respectively. These alpha-index values are consistent with those measured by White et al. and Parejko et al. In summary, our study provides independent support for the HOD models assumed during the development of the BOSS mock-galaxy catalogues that have subsequently been used to derive BOSS cosmological constraints.

  14. Counting on the mental number line to make a move: sensorimotor ('pen') control and numerical processing.

    Science.gov (United States)

    Sheridan, Rebecca; van Rooijen, Maaike; Giles, Oscar; Mushtaq, Faisal; Steenbergen, Bert; Mon-Williams, Mark; Waterman, Amanda

    2017-07-27

    Mathematics is often conducted with a writing implement. But is there a relationship between numerical processing and sensorimotor 'pen' control? We asked participants to move a stylus so it crossed an unmarked line at a location specified by a symbolic number (1-9), where number colour indicated whether the line ran left-right ('normal') or vice versa ('reversed'). The task could be simplified through the use of a 'mental number line' (MNL). Many modern societies use number lines in mathematical education and the brain's representation of number appears to follow a culturally determined spatial organisation (so better task performance is associated with this culturally normal orientation-the MNL effect). Participants (counter-balanced) completed two consistent blocks of trials, 'normal' and 'reversed', followed by a mixed block where line direction varied randomly. Experiment 1 established that the MNL effect was robust, and showed that the cognitive load associated with reversing the MNL not only affected response selection but also the actual movement execution (indexed by duration) within the mixed trials. Experiment 2 showed that an individual's motor abilities predicted performance in the difficult (mixed) condition but not the easier blocks. These results suggest that numerical processing is not isolated from motor capabilities-a finding with applied consequences.

  15. RSQRT: AN HEURISTIC FOR ESTIMATING THE NUMBER OF CLUSTERS TO REPORT

    Science.gov (United States)

    Bruso, Kelsey

    2012-01-01

    Clustering can be a valuable tool for analyzing large datasets, such as in e-commerce applications. Anyone who clusters must choose how many item clusters, K, to report. Unfortunately, one must guess at K or some related parameter. Elsewhere we introduced a strongly-supported heuristic, RSQRT, which predicts K as a function of the attribute or item count, depending on attribute scales. We conducted a second analysis where we sought confirmation of the heuristic, analyzing data sets from theUCImachine learning benchmark repository. For the 25 studies where sufficient detail was available, we again found strong support. Also, in a side-by-side comparison of 28 studies, RSQRT best-predicted K and the Bayesian information criterion (BIC) predicted K are the same. RSQRT has a lower cost of O(log log n) versus O(n2) for BIC, and is more widely applicable. Using RSQRT prospectively could be much better than merely guessing. PMID:22773923

  16. Copy number variants in the kallikrein gene cluster.

    Directory of Open Access Journals (Sweden)

    Pernilla Lindahl

    Full Text Available The kallikrein gene family (KLK1-KLK15 is the largest contiguous group of protease genes within the human genome and is associated with both risk and outcome of cancer and other diseases. We searched for copy number variants in all KLK genes using quantitative PCR analysis and analysis of inheritance patterns of single nucleotide polymorphisms. Two deletions were identified: one 2235-bp deletion in KLK9 present in 1.2% of alleles, and one 3394-bp deletion in KLK15 present in 4.0% of alleles. Each deletion eliminated one complete exon and created out-of-frame coding that eliminated the catalytic triad of the resulting truncated gene product, which therefore likely is a non-functional protein. Deletion breakpoints identified by DNA sequencing located the KLK9 deletion breakpoint to a long interspersed element (LINE repeated sequence, while the deletion in KLK15 is located in a single copy sequence. To search for an association between each deletion and risk of prostate cancer (PC, we analyzed a cohort of 667 biopsied men (266 PC cases and 401 men with no evidence of PC at biopsy using short deletion-specific PCR assays. There was no association between evidence of PC in this cohort and the presence of either gene deletion. Haplotyping revealed a single origin of each deletion, with most recent common ancestor estimates of 3000-8000 and 6000-14 000 years for the deletions in KLK9 and KLK15, respectively. The presence of the deletions on the same haplotypes in 1000 Genomes data of both European and African populations indicate an early origin of both deletions. The old age in combination with homozygous presence of loss-of-function variants suggests that some kallikrein-related peptidases have non-essential functions.

  17. Effect of imbalance and intracluster correlation coefficient in cluster randomization trials with binary outcomes when the available number of clusters is fixed in advance.

    Science.gov (United States)

    Ahn, Chul; Hu, Fan; Skinner, Celette Sugg; Ahn, Daniel

    2009-07-01

    In some cluster randomization trials, the number of clusters cannot exceed a specified maximum value due to cost constraints or other practical reasons. Donner and Klar [Donner A, and Klar N. Design and analysis of cluster randomization trials in health research. Oxford University Press 2000] provided the sample size formula for the number of subjects required per cluster when the number of clusters cannot exceed a specified maximum value. The sample size formula of Donner and Klar assumes that the number of subjects is the same in each cluster. In practical situations, the number of subjects may be different among clusters. We conducted simulation studies to investigate the effect of the cluster size variability (kappa) and the intracluster correlation coefficient (rho) on the power of the study in which the number of available clusters is fixed in advance. For the balanced case (kappa=1.0), i.e., equal cluster size among clusters, the sample size formula yielded empirical powers close to the nominal level even when the number of available clusters per group (k*) is as small as 10. The sample size formula yielded empirical powers close to the nominal level when the number of available clusters per group (k*) is at least 20 and the imbalance parameter (kappa) is at least 0.8. Empirical powers were close to the nominal level when (rho or =0.8, and k*=10) or (rho< or =0.02, kappa=0.8, and k*=20).

  18. Cosmological constraints from Sunyaev-Zeldovich cluster counts: An approach to account for missing redshifts

    Energy Technology Data Exchange (ETDEWEB)

    Bonaldi, A.; Battye, R. A.; Brown, M. L., E-mail: anna.bonaldi@manchester.ac.uk [Jodrell Bank Centre for Astrophysics, Alan Turing Building, School of Physics and Astronomy, The University of Manchester, Oxford Road, Manchester, M13 9PL (United Kingdom)

    2014-05-10

    The accumulation of redshifts provides a significant observational bottleneck when using galaxy cluster surveys to constrain cosmological parameters. We propose a simple method to allow the use of samples where there is a fraction of the redshifts that are not known. The simplest assumption is that the missing redshifts are randomly extracted from the catalog, but the method also allows one to take into account known selection effects in the accumulation of redshifts. We quantify the reduction in statistical precision of cosmological parameter constraints as a function of the fraction of missing redshifts for simulated surveys, and also investigate the impact of making an incorrect assumption for the distribution of missing redshifts.

  19. Temporal stability of magic-number metal clusters: beyond the shell closing model

    Science.gov (United States)

    Desireddy, Anil; Kumar, Santosh; Guo, Jingshu; Bolan, Michael D.; Griffith, Wendell P.; Bigioni, Terry P.

    2013-02-01

    The anomalous stability of magic-number metal clusters has been associated with closed geometric and electronic shells and the opening of HOMO-LUMO gaps. Despite this enhanced stability, magic-number clusters are known to decay and react in the condensed phase to form other products. Improving our understanding of their decay mechanisms and developing strategies to control or eliminate cluster instability is a priority, to develop a more complete theory of their stability, to avoid studying mixtures of clusters produced by the decay of purified materials, and to enable technology development. Silver clusters are sufficiently reactive to facilitate the study of the ambient temporal stability of magic-number metal clusters and to begin to understand their decay mechanisms. Here, the solution phase stability of a series of silver:glutathione (Ag:SG) clusters was studied as a function of size, pH and chemical environment. Cluster stability was found to be a non-monotonic function of size. Electrophoretic separations showed that the dominant mechanism involved the redistribution of mass toward smaller sizes, where the products were almost exclusively previously known cluster sizes. Optical absorption spectra showed that the smaller clusters evolved toward the two most stable cluster sizes. The net surface charge was found to play an important role in cluster stabilization although charge screening had no effect on stability, contrary to DLVO theory. The decay mechanism was found to involve the loss of Ag+ ions and silver glutathionates. Clusters could be stabilized by the addition of Ag+ ions and destabilized by either the addition of glutathione or the removal of Ag+ ions. Clusters were also found to be most stable in near neutral pH, where they had a net negative surface charge. These results provide new mechanistic insights into the control of post-synthesis stability and chemical decay of magic-number metal clusters, which could be used to develop design principles

  20. Finding Rare AGN: X-ray Number Counts of Chandra Sources in Stripe 82

    CERN Document Server

    LaMassa, Stephanie M; Glikman, Eilat; Cappelluti, Nico; Civano, Francesca; Comastri, Andrea; Treister, Ezequiel; Arifin,; Boehringer, Hans; Cardamone, Carie; Chon, Gayoung; Kephart, Miranda; Murray, Stephen S; Richards, Gordon; Ross, Nic; Rozner, Joshua S; Schawinski, Kevin

    2012-01-01

    We present the first results of a wide area X-ray survey within the Sloan Digital Sky Survey (SDSS) Stripe 82, a 300 deg$^2$ region of the sky with a substantial investment in multi-wavelength coverage. We analyzed archival {\\it Chandra} observations that cover 7.5 deg$^2$ within Stripe 82 ("Stripe 82 ACX"), reaching 4.5$\\sigma$ flux limits of 7.9$\\times10^{-16}$, 3.4$\\times10^{-15}$ and 1.8$\\times10^{-15}$ erg s$^{-1}$ cm$^{-2}$ in the soft (0.5-2 keV), hard (2-7 keV) and full (0.5-7 keV) bands, to find 774, 239 and 1118 X-ray sources, respectively. Three hundred twenty-one sources are detected only in the full band and 9 sources are detected solely in the soft band. Utilizing data products from the {\\it Chandra} Source Catalog, we construct independent Log$N$-Log$S$ relationships, detailing the number density of X-ray sources as a function of flux, which show general agreement with previous {\\it Chandra} surveys. We compare the luminosity distribution of Stripe 82 ACX with the smaller, deeper CDF-S + E-CDFS...

  1. ALMA Deep Field in SSA22: Source Catalog and Number Counts

    CERN Document Server

    Umehata, Hideki; Kohno, Kotaro; Ivison, R J; Smail, Ian; Hatsukade, Bunyo; Nakanishi, Kouichiro; Kato, Yuta; Ikarashi, Soh; Matsuda, Yuichi; Fujimoto, Seiji; Iono, Daisuke; Lee, Minju; Steidel, Charles C; Saito, Tomoki; Alexander, D M; Yun, Min S; Kubo, Mariko

    2016-01-01

    We present results from a deep 2'x3' (comoving scale of 3.7 Mpc x 5.5 Mpc at z=3) survey at 1.1 mm taken with the Atacama Large Millimeter/submillimeter Array (ALMA) in the SSA22 field. We observe the core region of a z = 3.09 protocluster, achieving a typical rms sensitivity of 60 micro-Jy/beam at a spatial resolution of 0".7. We detect 18 robust ALMA sources at a signal-to-noise ratio (SNR) > 5. Comparison between the ALMA map and a 1.1 mm map taken with the AzTEC camera on the Atacama Submillimeter Telescope Experiment (ASTE) indicates that three submillimeter sources discovered by the AzTEC/ASTE survey are resolved into eight individual submillimeter galaxies (SMGs) by ALMA. At least ten of our 18 ALMA SMGs have spectroscopic redshifts of z = 3.09, placing them in the protocluster. This shows that a number of dusty starburst galaxies are forming simultaneously in the core of the protocluster. The nine brightest ALMA SMGs with SNR > 10 have a median intrinsic angular size of 0".32+0".13-0".06 (2.4+1.0-0.4 ...

  2. The treatment of mixing in core helium burning models - II. Constraints from cluster star counts

    Science.gov (United States)

    Constantino, Thomas; Campbell, Simon W.; Lattanzio, John C.; van Duijneveldt, Adam

    2016-03-01

    The treatment of convective boundaries during core helium burning is a fundamental problem in stellar evolution calculations. In the first paper of this series, we showed that new asteroseismic observations of these stars imply they have either very large convective cores or semiconvection/partially mixed zones that trap g modes. We probe this mixing by inferring the relative lifetimes of asymptotic giant branch (AGB) and horizontal branch (HB) from R2, the observed ratio of these stars in recent HST photometry of 48 Galactic globular clusters. Our new determinations of R2 are more self-consistent than those of previous studies and our overall calculation of R2 = 0.117 ± 0.005 is the most statistically robust now available. We also establish that the luminosity difference between the HB and the AGB clump is Δ log {L}_HB^AGB = 0.455 ± 0.012. Our results accord with earlier findings that standard models predict a lower R2 than is observed. We demonstrate that the dominant sources of uncertainty in models are the prescription for mixing and the stochastic effects that can result from its numerical treatment. The luminosity probability density functions that we derive from observations feature a sharp peak near the AGB clump. This constitutes a strong new argument against core breathing pulses, which broaden the predicted width of the peak. We conclude that the two mixing schemes that can match the asteroseismology are capable of matching globular cluster observations, but only if (i) core breathing pulses are avoided in models with a semiconvection/partially mixed zone, or (ii) that models with large convective cores have a particular depth of mixing beneath the Schwarzschild boundary during subsequent early-AGB `gravonuclear' convection.

  3. Submucosa 1.0 x 0.1 mm in size is sufficient to count inflammatory cell numbers in human airway biopsy specimens

    NARCIS (Netherlands)

    ten Hacken, NHT; Aleva, RM; Oosterhoff, Y; Smith, M; Kraan, J; Postma, DS; Timens, W

    1998-01-01

    Counting of inflammatory cells in human airway biopsy specimens is difficult because immunopositive cells are present in varying density in lung tissue. The goal of our study was to assess the minimal amount of tissue that is necessary for the counting of constant cell numbers. In bronchial biopsy s

  4. The treatment of mixing in core helium burning models -- II. Constraints from cluster star counts

    CERN Document Server

    Constantino, Thomas; Lattanzio, John C; van Duijneveldt, Adam

    2015-01-01

    The treatment of convective boundaries during core helium burning is a fundamental problem in stellar evolution calculations. In Paper~I we showed that new asteroseismic observations of these stars imply they have either very large convective cores or semiconvection/partially mixed zones that trap g-modes. We probe this mixing by inferring the relative lifetimes of asymptotic giant branch (AGB) and horizontal branch (HB) from $R_2$, the observed ratio of these stars in recent HST photometry of 48 Galactic globular clusters. Our new determinations of $R_2$ are more self-consistent than those of previous studies and our overall calculation of $R_2 = 0.117 \\pm 0.005$ is the most statistically robust now available. We also establish that the luminosity difference between the HB and the AGB clump is $\\Delta \\log{L}_\\text{HB}^\\text{AGB} = 0.455 \\pm 0.012$. Our results accord with earlier findings that standard models predict a lower $R_2$ than is observed. We demonstrate that the dominant sources of uncertainty in ...

  5. A multi-sequential number-theoretic optimization algorithm using clustering methods

    Institute of Scientific and Technical Information of China (English)

    XU Qing-song; LIANG Yi-zeng; HOU Zhen-ting

    2005-01-01

    A multi-sequential number-theoretic optimization method based on clustering was developed and applied to the optimization of functions with many local extrema. Details of the procedure to generate the clusters and the sequential schedules were given. The algorithm was assessed by comparing its performance with generalized simulated annealing algorithm in a difficult instructive example and a D-optimum experimental design problem. It is shown the presented algorithm to be more effective and reliable based on the two examples.

  6. Cross-Cultural and Intra-Cultural Differences in Finger-Counting Habits and Number Magnitude Processing: Embodied Numerosity in Canadian and Chinese University Students

    Directory of Open Access Journals (Sweden)

    Kyle Richard Morrissey

    2016-04-01

    Full Text Available Recent work in numerical cognition has shown-that number magnitude is not entirely abstract, and at least partly rooted in embodied and situated experiences, including finger-counting. The current study extends previous cross-cultural research to address within-culture individual differences in finger counting habits. Results indicated that Canadian participants demonstrated an additional cognitive load when comparing numbers that require more than one hand to represent, and this pattern of performance is further modulated by whether they typically start counting on their left hand or their right hand. Chinese students typically count on only one hand and so show no such effect, except for an increase in errors, similar to that seen in Canadians, for those whom self-identify as predominantly two-hand counters. Results suggest that the impact of finger counting habits extend beyond cultural experience and concord in predictable ways with differences in number magnitude processing for specific number-digits. We conclude that symbolic number magnitude processing is partially rooted in learned finger-counting habits, consistent with a motor simulation account of embodied numeracy and that argument is supported by both cross-cultural and within-culture differences in finger-counting habits.

  7. Velocity fluctuations and population distribution in clusters of settling particles at low Reynolds number

    CERN Document Server

    Boschan, A; Annichini, M; Gauthier, G

    2016-01-01

    A study on the spatial organization and velocity fluctuations of non Brownian spherical particles settling at low Reynolds number in a vertical Hele-Shaw cell is reported. The particle volume fraction ranged from 0.005 to 0.05, while the distance between cell plates ranged from 5 to 15 times the particle radius. Particle tracking revealed that particles were not uniformly distributed in space but assembled in transient settling clusters. The population distribution of these clusters followed an exponential law. The measured velocity fluctuations are in agreement with that predicted theoretically for spherical clusters, from the balance between the apparent weight and the drag force. This result suggests that particle clustering, more than a spatial distribution of particles derived from random and independent events, is at the origin of the velocity fluctuations.

  8. Two-dimensional magic numbers in mass abundances of photofragmented bimetallic clusters

    CERN Document Server

    Janssens, E; Neukermans, S; Silverans, R E; Lievens, P

    2003-01-01

    The stability of cationic gold clusters doped with one transition metal atom was investigated by a mass spectrometric analysis of fragments resulting from high fluence irradiation of a cluster beam. Strongly enhanced abundances are found for Au sub 5 X sup + , X = V, Mn, Cr, Fe, Co, Zn, which implies that these species are far more stable towards fragmentation than their neighbouring cluster sizes. Here we interpret the enhanced stability of these clusters within a shell model approach for two-dimensional (2D) systems: the number of delocalized electrons in Au sub 5 X sup + is six, which is a magic number for 2D systems. Quantum chemical calculations for Au sub N Zn sup + (N = 2-6) predict planar structures that are stabilized by the influence of the dopant atom. Also, the main features of the calculated molecular orbitals are well reproduced by a simple electron-in-a-box model. The present report constitutes the first observation of 2D magic numbers in size dependent properties of metal clusters.

  9. ALMACAL I: First dual-band number counts from a deep and wide ALMA submm survey, free from cosmic variance

    CERN Document Server

    Oteo, I; Ivison, R J; Smail, I; Biggs, A D

    2015-01-01

    We have exploited ALMA calibration observations to carry out a novel, wide and deep submm survey, ALMACAL. These calibration data comprise a large number of observations of calibrator fields in a variety of frequency bands and array configurations. Gathering together data acquired during multiple visits to many ALMA calibrators, it is possible to reach noise levels which allow the detection of faint dusty, star-forming galaxies (DSFGs) over a significant area. In this paper we outline our survey strategy and report the first results. We have analysed data for 69 calibrators, reaching depths of $\\sim 25 \\, {\\rm \\mu Jy \\, beam^{-1}}$ at sub-arcsec resolution. Adopting a conservative approach based on $\\geq 5 \\sigma$ detections, we have found eight and 11 DSFGs in ALMA bands 6 and 7, respectively, with flux densities $S_{\\rm 1.2 mm} \\geq 0.2 \\, {\\rm mJy}$. The faintest galaxies would have been missed by even the deepest \\emph{Herschel} surveys. Our cumulative number counts have been determined independently at 8...

  10. A Clustering Algorithm for Planning the Integration Process of a Large Number of Conceptual Schemas

    Institute of Scientific and Technical Information of China (English)

    Carlo Batini; Paola Bonizzoni; Marco Comerio; Riccardo Dondi; Yuri Pirola; Francesco Salandra

    2015-01-01

    When tens and even hundreds of schemas are involved in the integration process, criteria are needed for choosing clusters of schemas to be integrated, so as to deal with the integration problem through an efficient iterative process. Schemas in clusters should be chosen according to cohesion and coupling criteria that are based on similarities and dissimilarities among schemas. In this paper, we propose an algorithm for a novel variant of the correlation clustering approach that addresses the problem of assisting a designer in integrating a large number of conceptual schemas. The novel variant introduces upper and lower bounds to the number of schemas in each cluster, in order to avoid too complex and too simple integration contexts respectively. We give a heuristic for solving the problem, being an NP hard combinatorial problem. An experimental activity demonstrates an appreciable increment in the effectiveness of the schema integration process when clusters are computed by means of the proposed algorithm w.r.t. the ones manually defined by an expert.

  11. Estimation of absolute microglial cell numbers in mouse fascia dentata using unbiased and efficient stereological cell counting principles.

    Science.gov (United States)

    Wirenfeldt, Martin; Dalmau, Ishar; Finsen, Bente

    2003-11-01

    Stereology offers a set of unbiased principles to obtain precise estimates of total cell numbers in a defined region. In terms of microglia, which in the traumatized and diseased CNS is an extremely dynamic cell population, the strength of stereology is that the resultant estimate is unaffected by shrinkage or expansion of the tissue. The optical fractionator technique is very efficient but requires relatively thick sections (e.g., > or =20 microm after coverslipping) and the unequivocal identification of labeled cells throughout the section thickness. We have adapted our protocol for Mac-1 immunohistochemical visualization of microglial cells in thick (70 microm) vibratome sections for stereological counting within the murine hippocampus, and we have compared the staining results with other selective microglial markers: the histochemical demonstration of nucleotide diphosphatase (NDPase) activity and the tomato lectin histochemistry. The protocol gives sections of high quality with a final mean section thickness of >20 microm (h=22.3 microm +/- 0.64 microm), and with excellent rendition of Mac-1+ microglia through the entire height of the section. The NDPase staining gives an excellent visualization of microglia, although with this thickness, the intensity of the staining is too high to distinguish single cells. Lectin histochemistry does not visualize microglia throughout the section and, accordingly, is not suited for the optical fractionator. The mean total number of Mac-1+ microglial cells in the unilateral dentate gyrus of the normal young adult male C57BL/6 mouse was estimated to be 12,300 (coefficient of variation (CV)=0.13) with a mean coefficient of error (CE) of 0.06. The perspective of estimating microglial cell numbers using stereology is to establish a solid basis for studying the dynamics of the microglial cell population in the developing and in the injured, diseased and normal adult CNS.

  12. 基于K-means聚类和椭圆拟合方法的白粉虱计数算法%Whiteflies counting with K-means clustering and ellipse fitting

    Institute of Scientific and Technical Information of China (English)

    王志彬; 王开义; 张水发; 刘忠强; 穆翠霞

    2014-01-01

    Insect pests are one of the important factors leading to crop loss. Accurate insect counts provide an important basis for pest detection, and for proper preventive measures to be taken. At present, the common counting methods are mainly based on computer vision, but this type of technology primarily has the following problems: 1) how to determine the threshold of image segmentation. The effects of the algorithms are unsatisfactory, as their thresholds or parameters are fixed when they are used to segment insect images. 2) Most counting algorithms are mainly aimed at one certain crop for learning and testing. If applied to other crops, their portability is poor, and the counting results are inaccurate. Therefore, how to improve the generalization and accuracy of counting algorithm is an important direction for research on a counting method based on machine vision. To solve the above problems, a novel counting algorithm for whiteflies based on k-means clustering and ellipse fitting method was proposed in this paper. It combined k-means clustering algorithm with ellipse fitting and automatically learned the features of whiteflies and background to segment and count whitefly images accurately. First, whitefly image were segmented by a k-means clustering algorithm to separate the whiteflies from the background, and then the segmentation results were fitted using an ellipse fitting based on least square method and adding up the ellipse number. The color features of the ellipse centers were extracted as new centers of classes. The segmentation and counting was iterated until the difference between two continuous counts met the needs of the algorithm and the convergence ellipse count was output as the number of whiteflies. Moreover, to improve the adaptability of the algorithm to count whiteflies on various crops, the whitefly images to be counted were parted into blocks and the center block was used to learn the features of whiteflies such as color, size, and area. The

  13. The 3-Dimensional q-Deformed Harmonic Oscillator and Magic Numbers of Alkali Metal Clusters

    CERN Document Server

    Bonatsos, Dennis; Raychev, P P; Roussev, R P; Terziev, P A; Bonatsos, Dennis

    1999-01-01

    Magic numbers predicted by a 3-dimensional q-deformed harmonic oscillator with Uq(3) > SOq(3) symmetry are compared to experimental data for alkali metal clusters, as well as to theoretical predictions of jellium models, Woods--Saxon and wine bottle potentials, and to the classification scheme using the 3n+l pseudo quantum number. The 3-dimensional q-deformed harmonic oscillator correctly predicts all experimentally observed magic numbers up to 1500 (which is the expected limit of validity for theories based on the filling of electronic shells), thus indicating that Uq(3), which is a nonlinear extension of the U(3) symmetry of the spherical (3-dimensional isotropic) harmonic oscillator, is a good candidate for being the symmetry of systems of alkali metal clusters.

  14. Spatial periodicity of galaxy number counts from Fourier analysis of the large scale surveys of galaxies in the Universe

    CERN Document Server

    Hartnett, John G

    2007-01-01

    A Fourier analysis has been carried out on the galaxy number count as a function of redshift, the $N$-$z$ relation, calculated from redshift data of both the Sloan Digital Sky Survey (SDSS) and the 2dF Galaxy Redshift Survey (2dF GRS). Regardless of the interpretation of those redshifts, the results indicate that galaxies have preferred periodic redshifts. This is the \\textit{picket-fence} structure observed by some. Application of the Hubble law, at low redshift, results in galaxies preferentially located on concentric shells with periodic spacings. This analysis finds significant redshift spacings of $\\Delta z =$ 0.0102, 0.0246, and 0.0448 in the SDSS and strong agreement with the results from 2dF GRS. The combined results from both surveys indicate regular real space spacings of $44.0 \\pm 2.5$ $Mpc$, $102 \\pm 8$ $Mpc$ and $176 \\pm 29$ $Mpc$, for an assumed Hubble's constant $H_0 = 72 km s^{-1} Mpc^{-1}$. These results indicate that it is a real effect and not some observational artifact. The effect is sign...

  15. Polycystic ovarian morphology and the diagnosis of polycystic ovary syndrome: redefining threshold levels for follicle count and serum anti-Müllerian hormone using cluster analysis.

    Science.gov (United States)

    Lie Fong, S; Laven, J S E; Duhamel, A; Dewailly, D

    2017-08-01

    Can cluster analysis be used to differentiate between normo-ovulatory women with normal ovaries and normo-ovulatory women with polycystic ovarian morphology (PCOM) in a non-subjective manner? Cluster analysis can be used to accurately and non-subjectively differentiate between normo-ovulatory women with normal ovaries and normo-ovulatory women with PCOM. Currently, PCOM is diagnosed using a fixed threshold level, i.e. 12 or more follicles per ovary, and is one of the diagnostic criteria of polycystic ovary syndrome (PCOS). However, PCOM is also encountered in normo-ovulatory women, suggesting that it could just represent a normal variant. On the other hand, recent studies have shown subtle endocrine abnormalities in women with isolated PCOM that resemble those found in women with PCOS. Because of the strong correlation between anti-Müllerian hormone (AMH) and follicle number, a high serum AMH level has been proposed as a surrogate marker for PCOM and could, therefore, be integrated in the diagnostic classifications for PCOS. This was a retrospective observational cohort study. Original cohorts had been recruited for previous studies between 1998 and 2010. Two hundred ninety-seven regularly cycling women and 700 women with PCOS were eligible for inclusion. Cluster analysis was performed in 297 regularly cycling women. After exclusion of 'PCOM' clusters, each 'non-PCOM' cluster (young, n = 118 and old, n = 100) was included in the construction of a receiver operating characteristics curve to test the diagnostic performance of follicle number per ovary (FNPO) and serum AMH in discriminating similarly aged full-blown PCOS patients (n = 411 and 237, respectively) from normal regularly cycling non-PCOM women. The optimal number of clusters was four; age was the most important classifying variable, followed by the FNPO and serum AMH. Two distinct clusters of normo-ovulatory women with PCOM were isolated and differed solely by age, i.e. 'young' and 'old'. Both 'PCOM

  16. High redshift galaxies in the ALHAMBRA survey . I. Selection method and number counts based on redshift PDFs

    Science.gov (United States)

    Viironen, K.; Marín-Franch, A.; López-Sanjuan, C.; Varela, J.; Chaves-Montero, J.; Cristóbal-Hornillos, D.; Molino, A.; Fernández-Soto, A.; Vilella-Rojo, G.; Ascaso, B.; Cenarro, A. J.; Cerviño, M.; Cepa, J.; Ederoclite, A.; Márquez, I.; Masegosa, J.; Moles, M.; Oteo, I.; Pović, M.; Aguerri, J. A. L.; Alfaro, E.; Aparicio-Villegas, T.; Benítez, N.; Broadhurst, T.; Cabrera-Caño, J.; Castander, J. F.; Del Olmo, A.; González Delgado, R. M.; Husillos, C.; Infante, L.; Martínez, V. J.; Perea, J.; Prada, F.; Quintana, J. M.

    2015-04-01

    Context. Most observational results on the high redshift restframe UV-bright galaxies are based on samples pinpointed using the so-called dropout technique or Ly-α selection. However, the availability of multifilter data now allows the dropout selections to be replaced by direct methods based on photometric redshifts. In this paper we present the methodology to select and study the population of high redshift galaxies in the ALHAMBRA survey data. Aims: Our aim is to develop a less biased methodology than the traditional dropout technique to study the high redshift galaxies in ALHAMBRA and other multifilter data. Thanks to the wide area ALHAMBRA covers, we especially aim at contributing to the study of the brightest, least frequent, high redshift galaxies. Methods: The methodology is based on redshift probability distribution functions (zPDFs). It is shown how a clean galaxy sample can be obtained by selecting the galaxies with high integrated probability of being within a given redshift interval. However, reaching both a complete and clean sample with this method is challenging. Hence, a method to derive statistical properties by summing the zPDFs of all the galaxies in the redshift bin of interest is introduced. Results: Using this methodology we derive the galaxy rest frame UV number counts in five redshift bins centred at z = 2.5,3.0,3.5,4.0, and 4.5, being complete up to the limiting magnitude at mUV(AB) = 24, where mUV refers to the first ALHAMBRA filter redwards of the Ly-α line. With the wide field ALHAMBRA data we especially contribute to the study of the brightest ends of these counts, accurately sampling the surface densities down to mUV(AB) = 21-22. Conclusions: We show that using the zPDFs it is easy to select a very clean sample of high redshift galaxies. We also show that it is better to do statistical analysis of the properties of galaxies using a probabilistic approach, which takes into account both the incompleteness and contamination issues in a

  17. Structural rearrangements and magic numbers in reactions between pyridine-containing water clusters and ammonia.

    Science.gov (United States)

    Ryding, Mauritz J; Ruusuvuori, Kai; Andersson, Patrik U; Zatula, Alexey S; McGrath, Matthew J; Kurtén, Theo; Ortega, Ismael K; Vehkamäki, Hanna; Uggerud, Einar

    2012-05-24

    Molecular cluster ions H(+)(H(2)O)(n), H(+)(pyridine)(H(2)O)(n), H(+)(pyridine)(2)(H(2)O)(n), and H(+)(NH(3))(pyridine)(H(2)O)(n) (n = 16-27) and their reactions with ammonia have been studied experimentally using a quadrupole-time-of-flight mass spectrometer. Abundance spectra, evaporation spectra, and reaction branching ratios display magic numbers for H(+)(NH(3))(pyridine)(H(2)O)(n) and H(+)(NH(3))(pyridine)(2)(H(2)O)(n) at n = 18, 20, and 27. The reactions between H(+)(pyridine)(m)(H(2)O)(n) and ammonia all seem to involve intracluster proton transfer to ammonia, thus giving clusters of high stability as evident from the loss of several water molecules from the reacting cluster. The pattern of the observed magic numbers suggest that H(+)(NH(3))(pyridine)(H(2)O)(n) have structures consisting of a NH(4)(+)(H(2)O)(n) core with the pyridine molecule hydrogen-bonded to the surface of the core. This is consistent with the results of high-level ab initio calculations of small protonated pyridine/ammonia/water clusters.

  18. Monoclonal B-cell lymphocytosis (MBL) with normal lymphocyte counts is associated with decreased numbers of normal circulating B-cell subsets.

    Science.gov (United States)

    Hauswirth, Alexander W; Almeida, Julia; Nieto, Wendy G; Teodosio, Cristina; Rodriguez-Caballero, Arancha; Romero, Alfonso; López, Antonio; Fernandez-Navarro, Paulino; Vega, Tomas; Perez-Andres, Martin; Valent, Peter; Jäger, Ulrich; Orfao, Alberto

    2012-07-01

    Monoclonal B-cell lymphocytosis (MBL) with normal lymphocyte counts is associated with decreased numbers of normal circulating B-cell subsets.Little is known about the distribution of normal lymphoid cells and their subsets in the peripheral blood (PB) of subjects with monoclonal B-cell lymphocytosis (MBL). In our study, we compared the absolute number of PB lymphoid cells and their subpopulations in 95 MBL cases with normal lymphocyte counts vs. 617 age-/sex-matched non-MBL healthy subjects (controls), using highly sensitive flow cytometry. MBL cases showed significantly reduced numbers of normal circulating B-cells, at the expense of immature and naive B-cells; in addition, CD4+CD8+ double-positive T-cells and CD8+ T-cells were significantly lower and higher vs. controls, respectively. Moreover, most normal B-cell subsets were significantly decreased in PB at >1% MBL-counts, vs. "low-count" MBL cases, and lower amounts of immature/naive B-cells were detected in biclonal (particularly in cases with coexisting CLL-like- and non-CLL-like B-cell clones) vs. monoclonal MBL subjects. In summary, our results show imbalanced (reduced) absolute numbers of recently produced normal circulating B-cells (e.g., immature and naıve B-cells) in MBL, which becomes more pronounced as the MBL cell count increases.

  19. Multi-hop routing-based optimization of the number of cluster-heads in wireless sensor networks.

    Science.gov (United States)

    Nam, Choon Sung; Han, Young Shin; Shin, Dong Ryeol

    2011-01-01

    Wireless sensor networks require energy-efficient data transmission because the sensor nodes have limited power. A cluster-based routing method is more energy-efficient than a flat routing method as it can only send specific data for user requirements and aggregate similar data by dividing a network into a local cluster. However, previous clustering algorithms have some problems in that the transmission radius of sensor nodes is not realistic and multi-hop based communication is not used both inside and outside local clusters. As energy consumption based on clustering is dependent on the number of clusters, we need to know how many clusters are best. Thus, we propose an optimal number of cluster-heads based on multi-hop routing in wireless sensor networks. We observe that a local cluster made by a cluster-head influences the energy consumption of sensor nodes. We determined an equation for the number of packets to send and relay, and calculated the energy consumption of sensor networks using it. Through the process of calculating the energy consumption, we can obtain the optimal number of cluster-heads in wireless sensor networks.

  20. Application of the Cluster Counting/Timing techniques to improve the performances of high transparency Drift Chamber for modern HEP experiments

    Science.gov (United States)

    Chiarello, G.; Chiri, C.; Cocciolo, G.; Corvaglia, A.; Grancagnolo, F.; Panareo, M.; Pepino, A.; Renga, F.; Tassielli, G. F.; Voena, C.

    2017-07-01

    Ultra-low mass and high granularity Drift Chambers seems to be a better choice for modern HEP experiments, to achieve a good momentum resolution on the charged particle. We present how, in Helium based gas mixture, by counting and measuring the arrival time of each individual ionization cluster and by using statistical tools, it is possible to reconstruct a bias free estimate of the impact parameter and a more discriminant Particle Identification.

  1. Vortex Clusters and Their Time Evolution in High- Reynolds-Number Turbulence

    Science.gov (United States)

    Ishihara, Takashi; Uno, Atsuya; Morishita, Koji; Yokokawa, Mitsuo; Kaneda, Yukio

    2016-11-01

    Time series data (with a time interval of 4τη) obtained by high-resolution direct numerical simulations (DNSs) of forced incompressible turbulence in a periodic box, with a maximum of 122883 grid points and Taylor micro-scale Reynolds numbers Rλ up to 2300, are used to study the vortex dynamics in high Reynolds number (Re) turbulent flows. Here τη is the Kolmogorov time scale. A visualization method to handle such large-scale data was developed for this study. In the high Re turbulence generated by the DNS, we observed the dynamics of tube-like vortex clusters of various sizes, which are constructed by strong micro vortices. For example, we observed the generation of the tube-like clusters of various sizes and the processes of their merging and breakdown. We also observed layer-like vortex clusters of the order of the integral length scale forming shear layers in the high Re turbulence. This research used computational resources of the K computer and other computers of the HPCI system provided by the AICS and the ITC of Nagoya University through the HPCI System Research Project (Project ID:hp150174, hp160102).

  2. Importance of Viral Sequence Length and Number of Variable and Informative Sites in Analysis of HIV Clustering.

    Science.gov (United States)

    Novitsky, Vlad; Moyo, Sikhulile; Lei, Quanhong; DeGruttola, Victor; Essex, M

    2015-05-01

    To improve the methodology of HIV cluster analysis, we addressed how analysis of HIV clustering is associated with parameters that can affect the outcome of viral clustering. The extent of HIV clustering and tree certainty was compared between 401 HIV-1C near full-length genome sequences and subgenomic regions retrieved from the LANL HIV Database. Sliding window analysis was based on 99 windows of 1,000 bp and 45 windows of 2,000 bp. Potential associations between the extent of HIV clustering and sequence length and the number of variable and informative sites were evaluated. The near full-length genome HIV sequences showed the highest extent of HIV clustering and the highest tree certainty. At the bootstrap threshold of 0.80 in maximum likelihood (ML) analysis, 58.9% of near full-length HIV-1C sequences but only 15.5% of partial pol sequences (ViroSeq) were found in clusters. Among HIV-1 structural genes, pol showed the highest extent of clustering (38.9% at a bootstrap threshold of 0.80), although it was significantly lower than in the near full-length genome sequences. The extent of HIV clustering was significantly higher for sliding windows of 2,000 bp than 1,000 bp. We found a strong association between the sequence length and proportion of HIV sequences in clusters, and a moderate association between the number of variable and informative sites and the proportion of HIV sequences in clusters. In HIV cluster analysis, the extent of detectable HIV clustering is directly associated with the length of viral sequences used, as well as the number of variable and informative sites. Near full-length genome sequences could provide the most informative HIV cluster analysis. Selected subgenomic regions with a high extent of HIV clustering and high tree certainty could also be considered as a second choice.

  3. Symmetry broken and restored coupled-cluster theory: II. Global gauge symmetry and particle number

    Science.gov (United States)

    Duguet, T.; Signoracci, A.

    2017-01-01

    We have recently extended many-body perturbation theory (MBPT) and coupled-cluster theory performed on top of a Slater determinant breaking rotational symmetry to allow for the restoration of the angular momentum at any truncation order (Duguet 2015 J. Phys. G: Nucl. Part. Phys. 42 025107). Following a similar route, we presently extend Bogoliubov MBPT and Bogoliubov coupled cluster theory performed on top of a Bogoliubov reference state breaking global gauge symmetry to allow for the restoration of the particle number at any truncation order. Eventually, formalisms can be merged to handle SU(2) and U(1) symmetries at the same time. The long-term goal relates to the ab initio description of near-degenerate finite quantum systems with an open-shell character.

  4. Relativistic Electron Shock Drift Acceleration in Low Mach Number Galaxy Cluster Shocks

    CERN Document Server

    Matsukiyo, Shuichi; Yamazaki, Ryo; Umeda, Takayuki

    2011-01-01

    An extreme case of electron shock drift acceleration in low Mach number collisionless shocks is investigated as a plausible mechanism of initial acceleration of relativistic electrons in large-scale shocks in galaxy clusters where upstream plasma temperature is of the order of 10 keV and a degree of magnetization is not too small. One-dimensional electromagnetic full particle simulations reveal that, even though a shock is rather moderate, a part of thermal incoming electrons are accelerated and reflected through relativistic shock drift acceleration and form a local nonthermal population just upstream of the shock. The accelerated electrons can self-generate local coherent waves and further be back-scattered toward the shock by those waves. This may be a scenario for the first stage of the electron shock acceleration occurring at the large-scale shocks in galaxy clusters such as CIZA J2242.8+5301 which has well defined radio relics.

  5. The Nustar Extragalactic Surveys: The Number Counts of Active Galactic Nuclei and the Resolved Fraction of the Cosmic X-Ray Background

    DEFF Research Database (Denmark)

    Harrison, F. A.; Aird, J.; Civano, F.;

    2016-01-01

    cm-2 ≤ 10-12, a factor ∼100 fainter than previous measurements. The 8–24 keV number counts match predictions from AGN populationsynthesis models, directly confirming the existence of a population of obscured and/or hard X-ray sources inferredfrom the shape of the integrated cosmic X-ray background...

  6. Counting the number of indecomposable representations and a q-analogue of the Weyl-Kac denominator identity of type _n

    Institute of Scientific and Technical Information of China (English)

    OBUL; Abdukadir

    2008-01-01

    By using Frobenius maps and F-stable representations,we count the number of isomor- phism classes of indecomposable representations with the fixed dimension vector of a species of type _n over a finite field,first,and then,as an application,give a q-analogue of the Weyl-Kac denominator identity of type _n.

  7. The Nustar Extragalactic Surveys: The Number Counts of Active Galactic Nuclei and the Resolved Fraction of the Cosmic X-Ray Background

    DEFF Research Database (Denmark)

    Harrison, F. A.; Aird, J.; Civano, F.

    2016-01-01

    . The measured NuSTAR counts lie significantly abovesimple extrapolation with a Euclidian slope to low flux of the Swift/BAT 15–55 keV number counts measured at higher fluxes (S(15–55 keV) ≤ 10−11 erg s-1 cm-2), reflecting the evolution of the AGN population between the Swift/BAT local (z ...STAR’s z ~ 1 sample. CXB synthesis models, which account for AGNevolution, lie above the Swift/BAT measurements, suggesting that they do not fully capture the evolution of obscured AGNs at low redshifts....

  8. Minimum number of clusters and comparison of analysis methods for cross sectional stepped wedge cluster randomised trials with binary outcomes: A simulation study.

    Science.gov (United States)

    Barker, Daniel; D'Este, Catherine; Campbell, Michael J; McElduff, Patrick

    2017-03-09

    Stepped wedge cluster randomised trials frequently involve a relatively small number of clusters. The most common frameworks used to analyse data from these types of trials are generalised estimating equations and generalised linear mixed models. A topic of much research into these methods has been their application to cluster randomised trial data and, in particular, the number of clusters required to make reasonable inferences about the intervention effect. However, for stepped wedge trials, which have been claimed by many researchers to have a statistical power advantage over the parallel cluster randomised trial, the minimum number of clusters required has not been investigated. We conducted a simulation study where we considered the most commonly used methods suggested in the literature to analyse cross-sectional stepped wedge cluster randomised trial data. We compared the per cent bias, the type I error rate and power of these methods in a stepped wedge trial setting with a binary outcome, where there are few clusters available and when the appropriate adjustment for a time trend is made, which by design may be confounding the intervention effect. We found that the generalised linear mixed modelling approach is the most consistent when few clusters are available. We also found that none of the common analysis methods for stepped wedge trials were both unbiased and maintained a 5% type I error rate when there were only three clusters. Of the commonly used analysis approaches, we recommend the generalised linear mixed model for small stepped wedge trials with binary outcomes. We also suggest that in a stepped wedge design with three steps, at least two clusters be randomised at each step, to ensure that the intervention effect estimator maintains the nominal 5% significance level and is also reasonably unbiased.

  9. Blue Straggler Stars a direct comparison of Star counts and population ratios in six Galactic Globular Clusters

    CERN Document Server

    Ferraro, F R; Rood, R T; Paltrinieri, B; Buonanno, R; Ferraro, Francesco R.; Sills, Alison; Rood, Robert T.; Paltrinieri, Barbara; Buonanno, Roberto

    2003-01-01

    The central regions of six Galactic Globular Clusters (GGCs) (M3, M80, M10, M13, M92 and NGC 288) have been imaged using HST-WFPC2 and the ultraviolet (UV) filters (F255W, F336W). The selected sample covers a large range in both central density and metallicity ([Fe/H]). In this paper, we present a direct cluster-to-cluster comparison of the Blue Stragglers Stars (BSS) population as selected from (m_{255},m_{255}-m_{336}) Color Magnitude Diagrams (CMDs). We have found:(a) BSS in three of the clusters (M3, M80, M92) are much more concentrated toward the center of the cluster than the red giants; because of the smaller BSS samples for the other clusters we can only note that the BSS radial distributions are consistent with central concentration; (b) the specific frequency of BSS varies greatly from cluster to cluster. The most interesting result is that the two clusters with largest BSS specific frequency are at the central density extremes of our sample: NGC 288 (lowest central density) and M80 (highest). This ...

  10. On identifying the optimal number of population clusters via the deviance information criterion.

    Science.gov (United States)

    Gao, Hong; Bryc, Katarzyna; Bustamante, Carlos D

    2011-01-01

    Inferring population structure using bayesian clustering programs often requires a priori specification of the number of subpopulations, K, from which the sample has been drawn. Here, we explore the utility of a common bayesian model selection criterion, the Deviance Information Criterion (DIC), for estimating K. We evaluate the accuracy of DIC, as well as other popular approaches, on datasets generated by coalescent simulations under various demographic scenarios. We find that DIC outperforms competing methods in many genetic contexts, validating its application in assessing population structure.

  11. Number of Clusters and the Quality of Hybrid Predictive Models in Analytical CRM

    Directory of Open Access Journals (Sweden)

    Łapczyński Mariusz

    2014-08-01

    Full Text Available Making more accurate marketing decisions by managers requires building effective predictive models. Typically, these models specify the probability of customer belonging to a particular category, group or segment. The analytical CRM categories refer to customers interested in starting cooperation with the company (acquisition models, customers who purchase additional products (cross- and up-sell models or customers intending to resign from the cooperation (churn models. During building predictive models researchers use analytical tools from various disciplines with an emphasis on their best performance. This article attempts to build a hybrid predictive model combining decision trees (C&RT algorithm and cluster analysis (k-means. During experiments five different cluster validity indices and eight datasets were used. The performance of models was evaluated by using popular measures such as: accuracy, precision, recall, G-mean, F-measure and lift in the first and in the second decile. The authors tried to find a connection between the number of clusters and models' quality.

  12. The NuSTAR Extragalactic Surveys: The Number Counts of Active Galactic Nuclei and the Resolved Fraction of the Cosmic X-Ray Background

    Science.gov (United States)

    Harrison, F. A.; Aird, J.; Civano, F.; Lansbury, G.; Mullaney, J. R.; Ballantyne, D. R.; Alexander, D. M.; Stern, D.; Ajello, M.; Barret, D.; Bauer, F. E.; Baloković, M.; Brandt, W. N.; Brightman, M.; Boggs, S. E.; Christensen, F. E.; Comastri, A.; Craig, W. W.; Del Moro, A.; Forster, K.; Gandhi, P.; Giommi, P.; Grefenstette, B. W.; Hailey, C. J.; Hickox, R. C.; Hornstrup, A.; Kitaguchi, T.; Koglin, J.; Luo, B.; Madsen, K. K.; Mao, P. H.; Miyasaka, H.; Mori, K.; Perri, M.; Pivovaroff, M.; Puccetti, S.; Rana, V.; Treister, E.; Walton, D.; Westergaard, N. J.; Wik, D.; Zappacosta, L.; Zhang, W. W.; Zoglauer, A.

    2016-11-01

    We present the 3-8 keV and 8-24 keV number counts of active galactic nuclei (AGNs) identified in the Nuclear Spectroscopic Telescope Array (NuSTAR) extragalactic surveys. NuSTAR has now resolved 33%-39% of the X-ray background in the 8-24 keV band, directly identifying AGNs with obscuring columns up to ˜ {10}25 {{cm}}-2. In the softer 3-8 keV band the number counts are in general agreement with those measured by XMM-Newton and Chandra over the flux range 5× {10}-15 ≲ S(3-8 keV)/{erg} {{{s}}}-1 {{cm}}-2 ≲ {10}-12 probed by NuSTAR. In the hard 8-24 keV band NuSTAR probes fluxes over the range 2× {10}-14 ≲ S(8-24 keV)/{erg} {{{s}}}-1 {{cm}}-2 ≲ {10}-12, a factor ˜100 fainter than previous measurements. The 8-24 keV number counts match predictions from AGN population synthesis models, directly confirming the existence of a population of obscured and/or hard X-ray sources inferred from the shape of the integrated cosmic X-ray background. The measured NuSTAR counts lie significantly above simple extrapolation with a Euclidian slope to low flux of the Swift/BAT 15-55 keV number counts measured at higher fluxes (S(15-55 keV) ≳ 10-11 {erg} {{{s}}}-1 {{cm}}-2), reflecting the evolution of the AGN population between the Swift/BAT local (z\\lt 0.1) sample and NuSTAR’s z˜ 1 sample. CXB synthesis models, which account for AGN evolution, lie above the Swift/BAT measurements, suggesting that they do not fully capture the evolution of obscured AGNs at low redshifts.

  13. Detection of Enhancement in Number Densities of Background Galaxies due to Magnification by Massive Galaxy Clusters

    Energy Technology Data Exchange (ETDEWEB)

    Chiu, I.; Dietrich, J. P.; Mohr, J. J.; Applegate, D. E.; Benson, B. A.; Bleem, L. E.; Bayliss, M. B.; Bocquet, S.; Carlstrom, J. E.; Capasso, R.

    2016-04-11

    We present a detection of the enhancement in the number densities of background galaxies induced from lensing magnification and use it to test the Sunyaev-Zel'dovich effect (SZE-) inferred masses in a sample of 19 galaxy clusters with median redshift z similar or equal to 0.42 selected from the South Pole Telescope SPT-SZ survey. These clusters are observed by the Megacam on the Magellan Clay Telescope though gri filters. Two background galaxy populations are selected for this study through their photometric colours; they have median redshifts zmedian similar or equal to 0.9 (low-z background) and z(median) similar or equal to 1.8 (high-z background). Stacking these populations, we detect the magnification bias effect at 3.3 sigma and 1.3 sigma for the low-and high-z backgrounds, respectively. We fit Navarro, Frenk and White models simultaneously to all observed magnification bias profiles to estimate the multiplicative factor. that describes the ratio of the weak lensing mass to the mass inferred from the SZE observable-mass relation. We further quantify systematic uncertainties in. resulting from the photometric noise and bias, the cluster galaxy contamination and the estimations of the background properties. The resulting. for the combined background populations with 1 sigma uncertainties is 0.83 +/- 0.24(stat) +/- 0.074(sys), indicating good consistency between the lensing and the SZE-inferred masses. We use our best-fitting eta to predict the weak lensing shear profiles and compare these predictions with observations, showing agreement between the magnification and shear mass constraints. This work demonstrates the promise of using the magnification as a complementary method to estimate cluster masses in large surveys.

  14. Detection of enhancement in number densities of background galaxies due to magnification by massive galaxy clusters

    Science.gov (United States)

    Chiu, I.; Dietrich, J. P.; Mohr, J.; Applegate, D. E.; Benson, B. A.; Bleem, L. E.; Bayliss, M. B.; Bocquet, S.; Carlstrom, J. E.; Capasso, R.; Desai, S.; Gangkofner, C.; Gonzalez, A. H.; Gupta, N.; Hennig, C.; Hoekstra, H.; von der Linden, A.; Liu, J.; McDonald, M.; Reichardt, C. L.; Saro, A.; Schrabback, T.; Strazzullo, V.; Stubbs, C. W.; Zenteno, A.

    2016-04-01

    We present a detection of the enhancement in the number densities of background galaxies induced from lensing magnification and use it to test the Sunyaev-Zel'dovich effect (SZE-) inferred masses in a sample of 19 galaxy clusters with median redshift z ≃ 0.42 selected from the South Pole Telescope SPT-SZ survey. These clusters are observed by the Megacam on the Magellan Clay Telescope though gri filters. Two background galaxy populations are selected for this study through their photometric colours; they have median redshifts zmedian ≃ 0.9 (low-z background) and zmedian ≃ 1.8 (high-z background). Stacking these populations, we detect the magnification bias effect at 3.3σ and 1.3σ for the low- and high-z backgrounds, respectively. We fit Navarro, Frenk and White models simultaneously to all observed magnification bias profiles to estimate the multiplicative factor η that describes the ratio of the weak lensing mass to the mass inferred from the SZE observable-mass relation. We further quantify systematic uncertainties in η resulting from the photometric noise and bias, the cluster galaxy contamination and the estimations of the background properties. The resulting η for the combined background populations with 1σ uncertainties is 0.83 ± 0.24(stat) ± 0.074(sys), indicating good consistency between the lensing and the SZE-inferred masses. We use our best-fitting η to predict the weak lensing shear profiles and compare these predictions with observations, showing agreement between the magnification and shear mass constraints. This work demonstrates the promise of using the magnification as a complementary method to estimate cluster masses in large surveys.

  15. Typical Methods of Counting the Number of Combinations%组合计数的几个典型方法

    Institute of Scientific and Technical Information of China (English)

    杨仁付

    2014-01-01

    在研究图的着色和树的计数问题中,遇到大量的复杂的计数问题,这些问题都不能用常规的计数方法来解决。交叉分类、发生函数以及Polya方法是解决这类问题的典型和有效方法,本文以代数学的视角阐述了这些方法的具体应用和解决技巧。%In the study of graph coloring and tree counting , numerous complicated counting problems are en-countered .These problems cannot be easily solved with ordinary counting methods .Cross-classification , and gener-ating function approach and Polya Theorem are typical and effective way to solve these problems .This paper de-scribes the perspective of algebra specific application of these methods and solving skills .

  16. Coagulation-fragmentation for a finite number of particles and application to telomere clustering in the yeast nucleus

    Science.gov (United States)

    Hozé, Nathanaël; Holcman, David

    2012-01-01

    We develop a coagulation-fragmentation model to study a system composed of a small number of stochastic objects moving in a confined domain, that can aggregate upon binding to form local clusters of arbitrary sizes. A cluster can also dissociate into two subclusters with a uniform probability. To study the statistics of clusters, we combine a Markov chain analysis with a partition number approach. Interestingly, we obtain explicit formulas for the size and the number of clusters in terms of hypergeometric functions. Finally, we apply our analysis to study the statistical physics of telomeres (ends of chromosomes) clustering in the yeast nucleus and show that the diffusion-coagulation-fragmentation process can predict the organization of telomeres.

  17. Find the Picture of Eight Turtles: A Link between Children's Counting and Their Knowledge of Number Word Semantics

    Science.gov (United States)

    Slusser, Emily B.; Sarnecka, Barbara W.

    2011-01-01

    An essential part of understanding number words (e.g., "eight") is understanding that all number words refer to the dimension of experience we call numerosity. Knowledge of this general principle may be separable from knowledge of individual number word meanings. That is, children may learn the meanings of at least a few individual number words…

  18. Cyclic single-molecule magnets: from the odd-numbered heptanuclear to a dimer of heptanuclear dysprosium clusters.

    Science.gov (United States)

    Tian, Haiquan; Bao, Song-Song; Zheng, Li-Min

    2016-02-01

    A heptanuclear and a dimer of heptanuclear dysprosium clusters (Dy7 and Dy14) have been successfully synthesized by ingenious coalescence of the single and double pyrazinyl hydrazone as well as phosphonate ligands. The complexes feature the largest odd-numbered cyclic lanthanide clusters reported thus far. Both exhibit single molecule magnet behaviors at low temperature.

  19. Fusion process of Lennard-Jones clusters: global minima and magic numbers formation

    DEFF Research Database (Denmark)

    Solov'yov, Ilia; Solov'yov, Andrey V.; Greiner, Walter

    2004-01-01

    We present a new theoretical framework for modeling the fusion process of Lennard–Jones (LJ) clusters. Starting from the initial tetrahedral cluster configuration, adding new atoms to the system and absorbing its energy at each step, we find cluster growing paths up to the cluster size of 150 atoms...

  20. Fusion process of Lennard-Jones clusters: global minima and magic numbers formation

    DEFF Research Database (Denmark)

    Solov'yov, Ilia; Solov'yov, Andrey V.; Greiner, Walter

    2004-01-01

    We present a new theoretical framework for modeling the fusion process of Lennard–Jones (LJ) clusters. Starting from the initial tetrahedral cluster configuration, adding new atoms to the system and absorbing its energy at each step, we find cluster growing paths up to the cluster size of 150 atoms...

  1. T-cell triggering thresholds are modulated by the number of antigen within individual T-cell receptor clusters

    Energy Technology Data Exchange (ETDEWEB)

    Manz, Boryana N. [Howard Hughes Medical Inst., Chevy Chase, MD (United States); Univ. of California, Berkeley, CA (United States); Jackson, Bryan L. [Howard Hughes Medical Inst., Chevy Chase, MD (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Petit, Rebecca S. [Howard Hughes Medical Inst., Chevy Chase, MD (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Dustin, Michael L. [New York School of Medicine, New York, NY (United States); Groves, Jay [Howard Hughes Medical Inst., Chevy Chase, MD (United States); Univ. of California, Berkeley, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2011-05-31

    T cells react to extremely small numbers of activating agonist peptides. Spatial organization of T-cell receptors (TCR) and their peptide-major histocompatibility complex (pMHC) ligands into microclusters is correlated with T-cell activation. In this study, we have designed an experimental strategy that enables control over the number of agonist peptides per TCR cluster, without altering the total number engaged by the cell. Supported membranes, partitioned with grids of barriers to lateral mobility, provide an effective way of limiting the total number of pMHC ligands that may be assembled within a single TCR cluster. Observations directly reveal that restriction of pMHC content within individual TCR clusters can decrease T-cell sensitivity for triggering initial calcium flux at fixed total pMHC density. Further analysis suggests that triggering thresholds are determined by the number of activating ligands available to individual TCR clusters, not by the total number encountered by the cell. Results from a series of experiments in which the overall agonist density and the maximum number of agonist per TCR cluster are independently varied in primary T cells indicate that the most probable minimal triggering unit for calcium signaling is at least four pMHC in a single cluster for this system. In conclusion, this threshold is unchanged by inclusion of coagonist pMHC, but costimulation of CD28 by CD80 can modulate the threshold lower.

  2. The NuSTAR Extragalactic Surveys: The Number Counts of Active Galactic Nuclei and the Resolved Fraction of the Cosmic X-ray Background

    CERN Document Server

    Harrison, F A; Civano, F; Lansbury, G; Mullaney, J R; Ballantyne, D R; Alexander, D M; Stern, D; Ajello, M; Barret, D; Bauer, F E; Balokovic, M; Brandt, W N; Brightman, M; Boggs, S E; Christensen, F E; Comastri, A; Craig, W W; Del Moro, A; Forster, K; Gandhi, P; Giommi, P; Grefenstette, B W; Hailey, C J; Hickox, R C; Hornstrup, A; Kitaguchi, T; Koglin, J; Luo, B; Madsen, K K; Mao, P H; Miyasaka, H; Mori, K; Perri, M; Pivovaroff, M; Puccetti, S; Rana, V; Treister, E; Walton, D; Westergaard, N J; Wik, D; Zappacosta, L; Zhang, W W; Zoglauer, A

    2015-01-01

    We present the 3-8 keV and 8-24 keV number counts of active galactic nuclei (AGN) identified in the NuSTAR extragalactic surveys. NuSTAR has now resolved approximately 35% of the X-ray background in the 8-24 keV band, directly identifying AGN with obscuring columns up to 1e25 / cm2. In the softer 3-8 keV band the number counts are in general agreement with those measured by XMM-Newton and Chandra over the flux range 5e-15 1e-11 erg/cm2/s, for any realistic AGN spectral model. The most natural explanation for the difference is an evolution in the AGN poulation between the very local objects seen by BAT and the more distant (0.5 < z < 1) NuSTAR sample that is not accounted for in the current models.

  3. The SCUBA-2 Cosmology Legacy Survey: ALMA resolves the bright-end of the sub-millimeter number counts

    CERN Document Server

    Simpson, James; Swinbank, Mark; Chapman, Scott; Geach, James; Ivison, Rob; Thomson, Alasdair; Aretxaga, Itziar; Blain, Andrew; Cowley, Will; Chen, Chian-Chou; Coppin, Kristen; Dunlop, Jim; Edge, Alastair; Farrah, Duncan; Ibar, Edo; Karim, Alex; Knudsen, Kirsten; Meijerink, Rowin; Michalowski, Michal; Scott, Douglas; Spanns, Marco; van der Werf, Paul

    2015-01-01

    We present high-resolution 870-um ALMA continuum maps of 30 bright sub-millimeter sources in the UKIDSS UDS field. These sources are selected from deep, 1-square degrees 850-um maps from the SCUBA--2 Cosmology Legacy Survey, and are representative of the brightest sources in the field (median SCUBA2 flux S_850=8.7+/-0.4 mJy). We detect 52 sub-millimeter galaxies (SMGs) at >4-sigma significance in our 30 ALMA maps. In 61+/-17% of the ALMA maps the single-dish source comprises a blend of >=2 SMGs, where the secondary SMGs are Ultra--Luminous Infrared Galaxies (ULIRGs) with L_IR>10^12 Lo. The brightest SMG contributes on average 80+/-4% of the single-dish flux density, and in the ALMA maps containing >=2 SMGs the secondary SMG contributes 25+/-3% of the integrated ALMA flux. We construct source counts and show that multiplicity boosts the apparent single-dish cumulative counts by 20% at S_870>7.5mJy, and by 60% at S_870>12mJy. We combine our sample with previous ALMA studies of fainter SMGs and show that the cou...

  4. Constraints on photoionization feedback from number counts of ultra-faint high-redshift galaxies in the Frontier Fields

    CERN Document Server

    Castellano, M; Ferrara, A; Merlin, E; Fontana, A; Amorín, R; Grazian, A; Mármol-Queralto, E; Michałowski, M J; Mortlock, A; Paris, D; Parsa, S; Pilo, S; Santini, P

    2016-01-01

    We exploit a sample of ultra-faint high-redshift galaxies (demagnified HST $H_{160}$ magnitude $>30$) in the Frontier Fields clusters A2744 and M0416 to constrain a theoretical model for the UV luminosity function (LF) in the presence of photoionization feedback. The objects have been selected on the basis of accurate photometric redshifts computed from multi-band photometry including 7 HST bands and deep $K_s$ and IRAC observations. Magnification is computed on an object-by-object basis from all available lensing models of the two clusters. We take into account source detection completeness as a function of luminosity and size, magnification effects and systematics in the lens modeling of the clusters under investigation. We find that our sample of high-$z$ galaxies constrain the cut-off halo circular velocity below which star-formation is suppressed by photo-ionization feedback to $v_c^{\\rm cut} < 50$ km s$^{-1}$. This circular velocity corresponds to a halo mass of $\\approx5.6\\times10^9~M_\\odot$ and $\\a...

  5. Solving the long-standing discrepancy in the Microlensing Optical Depth Toward the Galactic Bulge by correcting the stellar number count

    CERN Document Server

    Sumi, T

    2016-01-01

    We find that significant incompleteness in stellar number counts results in a significant overestimate of the microlensing optical depth $\\tau$ and event rate per star per year $\\Gamma$ toward the Galactic bulge from the first two years of MOA-II survey. We find that the completeness in Red Clump Giant (RCG) counts $f_{\\rm RC}$ decreases proportional to the galactic latitude $b$, as $f_{\\rm RC}=(0.63\\pm0.11)-(0.052\\pm0.028)\\times b$, ranging 1-0.7 at $b=-6^\\circ\\sim-1.5^\\circ$. This caused overestimates in $\\tau$ and $\\Gamma$. The previous measurements with all source by Difference Image Analysis (DIA) by MACHO and MOA-I suffer the same bias due to their relatively poor seeing. On the other hand, the measurements with RCG sample by OGLE-II, MACHO and EROS were free from this bias because they seldomected only the events associated to the resolved stars. Thus, the incompleteness both in the number of events and stellar number count cancel out. We estimate $\\tau$ and $\\Gamma$ by correcting this incompleteness. ...

  6. Separation Number and Generalized Clustering Coefficient in Small World Networks based on String Formalism

    CERN Document Server

    Toyota, Norihito

    2011-01-01

    We reformulated the string formalism given by Aoyama, using an adjacent matrix of a network and introduced a series of generalized clustering coefficients based on it. Furthermore we numerically evaluated Milgram condition proposed by their article in order to explore $q$-$th$ degrees of separation in scale free networks. In this article, we apply the reformulation to small world networks and numerically evaluate Milgram condition, especially the separation number of small world networks and its relation to cycle structures are discussed. Considering the number of non-zero elements of an adjacent matrix, the average path length and Milgram condition, we show that the formalism proposed by us is effective to analyze the six degrees of separation, especially effective for analyzing the relation between the separation number and cycle structures in a network. By this analysis of small world networks, it proves that a sort of power low holds between $M_n$, which is a key quantity in Milgram condition, and the gen...

  7. Coagulation–fragmentation for a finite number of particles and application to telomere clustering in the yeast nucleus

    Energy Technology Data Exchange (ETDEWEB)

    Hozé, Nathanaël [Ecole Normale Supérieure, Institute of Biology (IBENS), Group of Computational Biology and Applied Mathematics, 46 rue d' Ulm, 75005 Paris (France); Holcman, David, E-mail: holcman@biologie.ens.fr [Ecole Normale Supérieure, Institute of Biology (IBENS), Group of Computational Biology and Applied Mathematics, 46 rue d' Ulm, 75005 Paris (France); Department of Applied Mathematics, UMR 7598, Université Pierre et Marie Curie 187, 75252 Paris Cedex 05 (France)

    2012-01-30

    We develop a coagulation–fragmentation model to study a system composed of a small number of stochastic objects moving in a confined domain, that can aggregate upon binding to form local clusters of arbitrary sizes. A cluster can also dissociate into two subclusters with a uniform probability. To study the statistics of clusters, we combine a Markov chain analysis with a partition number approach. Interestingly, we obtain explicit formulas for the size and the number of clusters in terms of hypergeometric functions. Finally, we apply our analysis to study the statistical physics of telomeres (ends of chromosomes) clustering in the yeast nucleus and show that the diffusion–coagulation–fragmentation process can predict the organization of telomeres. -- Highlights: ► We develop a coagulation–fragmentation model to study a system composed of a small number of stochastic particles. ► The stochastic objects are moving in a confined domain. ► We apply our analysis to study the statistical physics of telomeres (ends of chromosomes) clustering in the yeast nucleus. ► We show that the diffusion–coagulation–fragmentation process can predict the organization of telomeres in yeast.

  8. The search for true numbers of neurons and glial cells in the human brain: A review of 150 years of cell counting.

    Science.gov (United States)

    von Bartheld, Christopher S; Bahney, Jami; Herculano-Houzel, Suzana

    2016-12-15

    For half a century, the human brain was believed to contain about 100 billion neurons and one trillion glial cells, with a glia:neuron ratio of 10:1. A new counting method, the isotropic fractionator, has challenged the notion that glia outnumber neurons and revived a question that was widely thought to have been resolved. The recently validated isotropic fractionator demonstrates a glia:neuron ratio of less than 1:1 and a total number of less than 100 billion glial cells in the human brain. A survey of original evidence shows that histological data always supported a 1:1 ratio of glia to neurons in the entire human brain, and a range of 40-130 billion glial cells. We review how the claim of one trillion glial cells originated, was perpetuated, and eventually refuted. We compile how numbers of neurons and glial cells in the adult human brain were reported and we examine the reasons for an erroneous consensus about the relative abundance of glial cells in human brains that persisted for half a century. Our review includes a brief history of cell counting in human brains, types of counting methods that were and are employed, ranges of previous estimates, and the current status of knowledge about the number of cells. We also discuss implications and consequences of the new insights into true numbers of glial cells in the human brain, and the promise and potential impact of the newly validated isotropic fractionator for reliable quantification of glia and neurons in neurological and psychiatric diseases. J. Comp. Neurol. 524:3865-3895, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  9. Revision of single atom local density and capture number varying with coverage in uniform depletion approximation and its effect on coalescence and number of stable clusters

    Institute of Scientific and Technical Information of China (English)

    Shao Qing-Yi; Zhang Juan

    2011-01-01

    In vapour deposition,single atoms(adatoms)on the substrate surface are the main source of growth.The change in its density plays a decisive role in the growth of thin films and quantum size islands.In the nucleation and cluster coalescence stages of vapour deposition,the growth of stable clusters occurs on the substrate surface covered by stable clusters.Nucleation occurs in the non-covered part,while the total area covered by stable clusters on the substrate surface will gradually increase.Carefully taking into account the coverage effect,a revised single atom density rate equation is given for the famous and widely used thin-film rate equation theory,but the work of solving the revised equation has not been done.In this paper,we solve the equation and obtain the single-atom density and capture number by using a uniform depletion approximation.We determine that the single atom density is much lower than that evaluated from the single atom density rate equation in the traditional rate equation theory when the stable cluster coverage fraction is large,and it goes down very fast with an increase in the coverage fraction.The revised equation gives a higher value for the 'average' capture number than the present equation. It also increases with increasing coverage.That makes the preparation of single crystalline thin film materials difficult and the size control of quantum size islands complicated.We also discuss the effect of the revision on coalescence and the number of stable clusters in vapour deposition.

  10. Constraints on neutrino masses from the study of the nearby large-scale structure and galaxy cluster counts

    CERN Document Server

    Boehringer, Hans

    2016-01-01

    The high precision measurements of the cosmic microwave background by the Planck survey yielded tight constraints on cosmological parameters and the statistics of the density fluctuations at the time of recombination. This provides the means for a critical study of structure formation in the Universe by comparing the microwave background results with present epoch measurements of the cosmic large-scale structure. It can reveal subtle effects such as how different forms of Dark Matter may modify structure growth. Currently most interesting is the damping effect of structure growth by massive neutrinos. Different observations of low redshift matter density fluctuations provided evidence for a signature of massive neutrinos. Here we discuss the study of the cosmic large-scale structure with a complete sample of nearby, X-ray luminous clusters from our REFLEX cluster survey. From the observed X-ray luminosity function and its reproduction for different cosmological models, we obtain tight constraints on the cosmo...

  11. Extragalactic millimeter-wave point-source catalog, number counts and statistics from 771 deg{sup 2} of the SPT-SZ survey

    Energy Technology Data Exchange (ETDEWEB)

    Mocanu, L. M.; Crawford, T. M.; Benson, B. A.; Bleem, L. E.; Carlstrom, J. E.; Chang, C. L.; Crites, A. T. [Kavli Institute for Cosmological Physics, University of Chicago, Chicago, IL 60637 (United States); Vieira, J. D. [California Institute of Technology, Pasadena, CA 91125 (United States); Aird, K. A. [University of Chicago, Chicago, IL 60637 (United States); Aravena, M. [European Southern Observatory, Alonso de Córdova 3107, Vitacura Santiago (Chile); Austermann, J. E.; Everett, W. B.; Halverson, N. W. [Department of Astrophysical and Planetary Sciences and Department of Physics, University of Colorado, Boulder, CO 80309 (United States); Béthermin, M. [Laboratoire AIM-Paris-Saclay, CEA/DSM/Irfu-CNRS-Université Paris Diderot, CEA-Saclay, Orme des Merisiers, F-91191 Gif-sur-Yvette (France); Bothwell, M. [Cavendish Laboratory, University of Cambridge, 19 J.J. Thomson Avenue, Cambridge CB3 0HE (United Kingdom); Chapman, S. [Department of Physics and Atmospheric Science, Dalhousie University, Halifax NS B3H 3J5 (Canada); Cho, H.-M. [NIST Quantum Devices Group, Boulder, CO 80305 (United States); De Haan, T.; Dobbs, M. A. [Department of Physics, McGill University, Montreal, Quebec H3A 2T8 (Canada); George, E. M., E-mail: lmocanu@uchicago.edu [Department of Physics, University of California, Berkeley, CA 94720 (United States); and others

    2013-12-10

    We present a point-source catalog from 771 deg{sup 2} of the South Pole Telescope Sunyaev-Zel'dovich survey at 95, 150, and 220 GHz. We detect 1545 sources above 4.5σ significance in at least one band. Based on their relative brightness between survey bands, we classify the sources into two populations, one dominated by synchrotron emission from active galactic nuclei, and one dominated by thermal emission from dust-enshrouded star-forming galaxies. We find 1238 synchrotron and 307 dusty sources. We cross-match all sources against external catalogs and find 189 unidentified synchrotron sources and 189 unidentified dusty sources. The dusty sources without counterparts are good candidates for high-redshift, strongly lensed submillimeter galaxies. We derive number counts for each population from 1 Jy down to roughly 11, 4, and 11 mJy at 95, 150, and 220 GHz. We compare these counts with galaxy population models and find that none of the models we consider for either population provide a good fit to the measured counts in all three bands. The disparities imply that these measurements will be an important input to the next generation of millimeter-wave extragalactic source population models.

  12. Review of Sex, Drugs and Body Counts: The Politics of Numbers in Global Crime and Conflict, edited by Peter Andreas and Kelly M. Greenhill

    Directory of Open Access Journals (Sweden)

    Aaron G. Montgomery

    2011-01-01

    Full Text Available Andreas, Peter, and Greenhill, Kelly M. (Eds.. Sex, Drugs, and Body Counts: The Politics of Numbers in Global Crime and Conflict, (Ithaca, NY: Cornell University Press, 2010. 287 pp. ISBN 978-0-8014-4861-4 (cloth; ISBN 978-0-8014-7618-1 (pbk.The ten scholarly papers in Sex, Drugs and Body Counts explore the generation and propagation of numbers that drive policy decisions in the U.S. government regarding human trafficking, drug trade, and armed conflict (including the war on terror. Each of these papers, written by different authors, provides an illuminating insight into how some of the numbers we hear or read in the news are derived. While the general message of the papers tends to be depressing, namely that the numbers driving U.S. policy vary from being slightly suspect to clearly fabricated, the book does provide positive examples of how accurate numbers can be obtained and how the numbers that are being used can be interpreted. As a teaching resource, the book provides instructors an opportunity to deepen their understanding of how quantitative data are used in U.S. policy, allowing them to explore these issues in class. Individual papers from the book could be used in a general education course (either in mathematics or in a field related to the topics as a way to introduce students to reading quantitatively dense material. In a course more focused on the topics of the book and with a more quantitatively literate audience, the entire book could probably be assigned as reading.

  13. Infrared-faint radio sources: a cosmological view. AGN number counts, the cosmic X-ray background and SMBH formation

    Science.gov (United States)

    Zinn, P.-C.; Middelberg, E.; Ibar, E.

    2011-07-01

    Context. Infrared-faint radio sources (IFRS) are extragalactic emitters clearly detected at radio wavelengths but barely detected or undetected at optical and infrared wavelengths, with 5σ sensitivities as low as 1 μJy. Aims: Spectral energy distribution (hereafter SED) modelling and analyses of their radio properties indicate that IFRS are consistent with a population of (potentially extremely obscured) high-redshift AGN at 3 ≤ z ≤ 6. We demonstrate some astrophysical implications of this population and compare them to predictions from models of galaxy evolution and structure formation. Methods: We compiled a list of IFRS from four deep extragalactic surveys and extrapolated the IFRS number density to a survey-independent value of (30.8 ± 15.0) deg-2. We computed the IFRS contribution to the total number of AGN in the Universe to account for the cosmic X-ray background. By estimating the black hole mass contained in IFRS, we present conclusions for the SMBH mass density in the early universe and compare it to relevant simulations of structure formation after the Big Bang. Results: The number density of AGN derived from the IFRS density was found to be ~310 deg-2, which is equivalent to a SMBH mass density of the order of 103 M⊙ Mpc-3 in the redshift range 3 ≤ z ≤ 6. This produces an X-ray flux of 9 × 10-16 W m-2 deg-2 in the 0.5-2.0 keV band and 3 × 10-15 W m-2 deg-2 in the 2.0-10 keV band, in agreement with the missing unresolved components of the Cosmic X-ray Background. To address SMBH formation after the Big Bang we invoke a scenario involving both halo gas accretion and major mergers.

  14. Artificial Neural Network to Modeling Zero-inflated Count Data: Application to Predicting Number of Return to Blood Donation.

    Science.gov (United States)

    Haghani, Shima; Sedehi, Morteza; Kheiri, Soleiman

    2017-09-02

    Traditional statistical models often are based on certain presuppositions and limitations that may not presence in actual data and lead to turbulence in estimation or prediction. In these situations, artificial neural networks (ANNs) could be suitable alternative rather than classical statistical methods.  A prospective cohort study. The study was conducted in Shahrekord Blood Transfusion Center, Shahrekord, central Iran, on blood donors from 2008-2009. The accuracy of the proposed model to prediction of number of return to blood donations was compared with classical statistical models. A number of 864 donors who had a first-time successful donation were followed for five years. Number of return for blood donation was considered as response variable. Poisson regression (PR), negative binomial regression (NBR), zero-inflated Poisson regression (ZIPR) and zero-inflated negative binomial regression (ZINBR) as well as ANN model were fitted to data. MSE criterion was used to compare models. To fitting the models, STATISTICA 10 and, R 3.2.2 was used RESULTS: The MSE of PR, NBR, ZIPR, ZINBR and ANN models was obtained 2.71, 1.01, 1.54, 0.094 and 0.056 for the training and 4.05, 9.89, 3.99, 2.53 and 0.27 for the test data, respectively. The ANN model had the least MSE in both training, and test data set and has a better performance than classic models. ANN could be a suitable alternative for modeling such data because of fewer restrictions.

  15. Infrared-Faint Radio Sources: A Cosmological View - AGN Number Counts, the Cosmic X-Ray Background and SMBH Formation

    CERN Document Server

    Zinn, Peter-Christian; Ibar, Edo

    2011-01-01

    Context. Infrared Faint Radio Sources (IFRS) are extragalactic emitters clearly detected at radio wavelengths but barely detected or undetected at optical and infrared wavelengths, with 5 sigma sensitivities as low as 1 uJy. Aims. Recent SED-modelling and analysis of their radio properties shows that IFRS are consistent with a population of (potentially extremely obscured) high-redshift AGN at 3number density to a survey-independent value of (30.8 +- 15.0) per square degree. We computed the IFRS contribution to the total number of AGN in the Universe to account for the Cosmic X-ray Background. By estimating the black hole mass contained in IFRS, we present conclusions for the SMBH mass density in the early universe and compare it to relevant simula...

  16. Photon counting with photon number resolution through superconducting nanowires coupled to a multi-channel TDC in FPGA

    Science.gov (United States)

    Lusardi, N.; Los, J. W. N.; Gourgues, R. B. M.; Bulgarini, G.; Geraci, A.

    2017-03-01

    The paper presents a system for measuring photon statistics and photon timing in the few-photon regime down to the single-photon level. The measurement system is based on superconducting nanowire single photon detectors and a time-to-digital converter implemented into a programmable device. The combination of these devices gives high performance to the system in terms of resolution and adaptability to the actual experimental conditions. As a case of application, we present the measurement of photon statistics for coherent light states. In this measurement, we make use of 8th order single photon correlations to reconstruct with high fidelity the statistics of a coherent state with average photon number up to 4. The processing is performed by means of a tapped-delay-line time-to-digital converter architecture that also hosts an asynchronous-correlated-digital-counter implemented in a field programmable gate array device and specifically designed for performance optimization in multi-channel usage.

  17. Analytic view at alpha clustering in even-even heavy nuclei near magic numbers 82 and 126

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed, Saad M.S. [Universiti Kebangsaan Malaysia, School of Applied Physics, Faculty of Science and Technology, Selangor (Malaysia); University of Malaya, Department of Physics, Faculty of Science, Kuala Lumpur (Malaysia); University of Malaya, Quantum Science Centre, Department of Physics, Faculty of Science, Kuala Lumpur (Malaysia); Yahaya, Redzuwan; Radiman, Shahidan; Yasir, Muhamad Samudi [Universiti Kebangsaan Malaysia, School of Applied Physics, Faculty of Science and Technology, Selangor (Malaysia); Kassim, Hasan Abu; Khandaker, Mayeen Uddin [University of Malaya, Department of Physics, Faculty of Science, Kuala Lumpur (Malaysia); University of Malaya, Quantum Science Centre, Department of Physics, Faculty of Science, Kuala Lumpur (Malaysia)

    2015-02-01

    Most studies on the determination of the alpha-decay preformation factor have used decay formulae. The preformation factor is known to contain abundant information on the nuclear structure. The successful determination of the preformation factor through the cluster formation model (CFM) motivates this study to determine the factor for nuclei near the magic numbers and present results in an analytic study based on different comparisons and observations. The difference between preformation factors obtained from CFM and from the decay formula method is significant. The formula method is used for the entire process of alpha decay as a transition between two states, whereas CFM is applied for the initial state of alpha formation. The preformation factor obtained using CFM and clusterization state representation was first compared with that obtained from the decay formula. Results were used to investigate alpha formation in even-even heavy nuclei, including 72 < Z < 92 and 92 < N < 142, near the magic numbers Z = 82 and N = 126. The values of the preformation factor were discussed and explained in detail according to the clusterization state representation to describe the most possible states of ground-state nuclei. The alpha clustering described through CFM is found to be consistent with that described using the decay formula for the open-shell nuclei of N < 126. The presence of more nucleons in the open-shell nuclei results in lower probability for alpha clustering and lower value of the preformation factor. However, few nucleons beyond the closed shell can cause higher probability for alpha clustering and larger value of the preformation factor. The maximum and minimum of the alpha-cluster formation occur in the nucleus of the double-shell closure (with N = 126 and Z = 82) and in the nucleus of two protons and two neutrons more. This formation probability is sensitive to the subshells, leading to the possibility of more clusterization states, including core-cluster

  18. Numbers of presynaptic Ca(2+) channel clusters match those of functionally defined vesicular docking sites in single central synapses.

    Science.gov (United States)

    Miki, Takafumi; Kaufmann, Walter A; Malagon, Gerardo; Gomez, Laura; Tabuchi, Katsuhiko; Watanabe, Masahiko; Shigemoto, Ryuichi; Marty, Alain

    2017-06-27

    Many central synapses contain a single presynaptic active zone and a single postsynaptic density. Vesicular release statistics at such "simple synapses" indicate that they contain a small complement of docking sites where vesicles repetitively dock and fuse. In this work, we investigate functional and morphological aspects of docking sites at simple synapses made between cerebellar parallel fibers and molecular layer interneurons. Using immunogold labeling of SDS-treated freeze-fracture replicas, we find that Cav2.1 channels form several clusters per active zone with about nine channels per cluster. The mean value and range of intersynaptic variation are similar for Cav2.1 cluster numbers and for functional estimates of docking-site numbers obtained from the maximum numbers of released vesicles per action potential. Both numbers grow in relation with synaptic size and decrease by a similar extent with age between 2 wk and 4 wk postnatal. Thus, the mean docking-site numbers were 3.15 at 2 wk (range: 1-10) and 2.03 at 4 wk (range: 1-4), whereas the mean numbers of Cav2.1 clusters were 2.84 at 2 wk (range: 1-8) and 2.37 at 4 wk (range: 1-5). These changes were accompanied by decreases of miniature current amplitude (from 93 pA to 56 pA), active-zone surface area (from 0.0427 μm(2) to 0.0234 μm(2)), and initial success rate (from 0.609 to 0.353), indicating a tightening of synaptic transmission with development. Altogether, these results suggest a close correspondence between the number of functionally defined vesicular docking sites and that of clusters of voltage-gated calcium channels.

  19. Numbers of presynaptic Ca2+ channel clusters match those of functionally defined vesicular docking sites in single central synapses

    Science.gov (United States)

    Miki, Takafumi; Kaufmann, Walter A.; Malagon, Gerardo; Gomez, Laura; Tabuchi, Katsuhiko; Watanabe, Masahiko; Shigemoto, Ryuichi; Marty, Alain

    2017-01-01

    Many central synapses contain a single presynaptic active zone and a single postsynaptic density. Vesicular release statistics at such “simple synapses” indicate that they contain a small complement of docking sites where vesicles repetitively dock and fuse. In this work, we investigate functional and morphological aspects of docking sites at simple synapses made between cerebellar parallel fibers and molecular layer interneurons. Using immunogold labeling of SDS-treated freeze-fracture replicas, we find that Cav2.1 channels form several clusters per active zone with about nine channels per cluster. The mean value and range of intersynaptic variation are similar for Cav2.1 cluster numbers and for functional estimates of docking-site numbers obtained from the maximum numbers of released vesicles per action potential. Both numbers grow in relation with synaptic size and decrease by a similar extent with age between 2 wk and 4 wk postnatal. Thus, the mean docking-site numbers were 3.15 at 2 wk (range: 1–10) and 2.03 at 4 wk (range: 1–4), whereas the mean numbers of Cav2.1 clusters were 2.84 at 2 wk (range: 1–8) and 2.37 at 4 wk (range: 1–5). These changes were accompanied by decreases of miniature current amplitude (from 93 pA to 56 pA), active-zone surface area (from 0.0427 μm2 to 0.0234 μm2), and initial success rate (from 0.609 to 0.353), indicating a tightening of synaptic transmission with development. Altogether, these results suggest a close correspondence between the number of functionally defined vesicular docking sites and that of clusters of voltage-gated calcium channels. PMID:28607047

  20. Variations in CCL3L gene cluster sequence and non-specific gene copy numbers

    Directory of Open Access Journals (Sweden)

    Edberg Jeffrey C

    2010-03-01

    Full Text Available Abstract Background Copy number variations (CNVs of the gene CC chemokine ligand 3-like1 (CCL3L1 have been implicated in HIV-1 susceptibility, but the association has been inconsistent. CCL3L1 shares homology with a cluster of genes localized to chromosome 17q12, namely CCL3, CCL3L2, and, CCL3L3. These genes are involved in host defense and inflammatory processes. Several CNV assays have been developed for the CCL3L1 gene. Findings Through pairwise and multiple alignments of these genes, we have shown that the homology between these genes ranges from 50% to 99% in complete gene sequences and from 70-100% in the exonic regions, with CCL3L1 and CCL3L3 being identical. By use of MEGA 4 and BioEdit, we aligned sense primers, anti-sense primers, and probes used in several previously described assays against pre-multiple alignments of all four chemokine genes. Each set of probes and primers aligned and matched with overlapping sequences in at least two of the four genes, indicating that previously utilized RT-PCR based CNV assays are not specific for only CCL3L1. The four available assays measured median copies of 2 and 3-4 in European and African American, respectively. The concordance between the assays ranged from 0.44-0.83 suggesting individual discordant calls and inconsistencies with the assays from the expected gene coverage from the known sequence. Conclusions This indicates that some of the inconsistencies in the association studies could be due to assays that provide heterogenous results. Sequence information to determine CNV of the three genes separately would allow to test whether their association with the pathogenesis of a human disease or phenotype is affected by an individual gene or by a combination of these genes.

  1. PARTIAL TRAINING METHOD FOR HEURISTIC ALGORITHM OF POSSIBLE CLUSTERIZATION UNDER UNKNOWN NUMBER OF CLASSES

    Directory of Open Access Journals (Sweden)

    D. A. Viattchenin

    2009-01-01

    Full Text Available A method for constructing a subset of labeled objects which is used in a heuristic algorithm of possible  clusterization with partial  training is proposed in the  paper.  The  method  is  based  on  data preprocessing by the heuristic algorithm of possible clusterization using a transitive closure of a fuzzy tolerance. Method efficiency is demonstrated by way of an illustrative example.

  2. Unified description of magic numbers of metal clusters in terms of the 3-dimensional q-deformed harmonic oscillator

    CERN Document Server

    Bonatsos, Dennis; Lenis, D; Raychev, P P; Roussev, R P; Terziev, P A

    2000-01-01

    Magic numbers predicted by a 3-dimensional q-deformed harmonic oscillator with Uq(3)>SOq(3) symmetry are compared to experimental data for atomic clusters of alkali metals (Li, Na, K, Rb, Cs), noble metals (Cu, Ag, Au), divalent metals (Zn, Cd), and trivalent metals (Al, In), as well as to theoretical predictions of jellium models, Woods-Saxon and wine bottle potentials, and to the classification scheme using the 3n+l pseudo quantum number. In alkali metal clusters and noble metal clusters the 3-dimensional q-deformed harmonic oscillator correctly predicts all experimentally observed magic numbers up to 1500 (which is the expected limit of validity for theories based on the filling of electronic shells), while in addition it gives satisfactory results for the magic numbers of clusters of divalent metals and trivalent metals, thus indicating that Uq(3), which is a nonlinear extension of the U(3) symmetry of the spherical (3-dimensional isotropic) harmonic oscillator, is a good candidate for being the symmetry ...

  3. 计数式光纤Bragg光栅风速仪设计%Design of fiber Bragg grating anemometer using principle of number counting

    Institute of Scientific and Technical Information of China (English)

    景霞; 刘爱莲; 赵振刚; 谢涛; 李英娜; 肖范; 李川

    2015-01-01

    To eliminate influence of temperature fluctuations on wind speed measurement with anemometer,design a kind of fiber Bragg grating( FBG)anemometer using principle of number counting effectively and stably measure wind speed. This kind of anemometer has a wind cup,which has a speed cam,and the counting device consists of speed cam and a balanceable cantilever on which FBG is pasted. Based on linear relationship between wind speed and revolving speed of the wind cup,build sensing model,then can calculate according to numbers of central light wave changes,calculate wind speed and monitor wind speed live in the aim area. Wind tunnel experiments show that wind speed sensor using principle of number counting start up wind speed is 0. 9 m/s,linearity is 6% and sensitivity is 0. 65 r/m.%为消除温度波动变化对风速测量带来的影响,能更有效、稳定地测量风速,设计一种计数式光纤Bragg光栅( FBG)风速仪。风速仪采用风杯结构,在风杯转轮上设置转速凸轮,粘贴有FBG的等强度悬臂梁与转速凸轮组成计数装置。基于风杯转速与风速呈线性关系建立了传感模型,根据中心波长变化次数进行计数,从而计算出风速,实现了对风场内风速实时监测。风洞试验表明:计数式FBG风速传感器的起动风速为0.9 m/s,线性度为6%,灵敏度为0.65 r/m。

  4. An influence of the copy number of biosynthetic gene clusters on the production level of antibiotics in a heterologous host.

    Science.gov (United States)

    Manderscheid, Niko; Bilyk, Bohdan; Busche, Tobias; Kalinowski, Jörn; Paululat, Thomas; Bechthold, Andreas; Petzke, Lutz; Luzhetskyy, Andriy

    2016-08-20

    Streptomyces albus J1074 is a well-known host for heterologous expression of secondary metabolites. To further increase its potential and to study the influence of cluster multiplication, additional φC31-attachment site was integrated into its genome using a system for transposon mutagenesis. Four secondary metabolite clusters were expressed in strains with different numbers of attachment sites, ranging from one to three copies of the site. Secondary metabolite production was examined and a new compound could be detected, purified and its structure was elucidated.

  5. The trace of a substantial assembly of massive E-S0 galaxies at 0.8number counts

    CERN Document Server

    Prieto, Mercedes

    2015-01-01

    K-band galaxy number counts (GNCs) exhibit a slope change at K~17.5 mag not present in optical bands. To unveil the nature of this feature, we have derived the contribution of different galaxy types to the total K-band GNCs at 0.32 cannot predict the slope change, whereas those imposing a relatively late assembly on them (z<1.5) can reproduce it. The K-band GNCs by redshift bins and morphological types point to a progressively definitive build-up of ~50% of this galaxy population at 0.8

  6. Evaluation of a method using survey counts and tag data to estimate the number of Pacific walruses (Odobenus rosmarus divergens) using a coastal haulout in northwestern Alaska

    Science.gov (United States)

    Battaile, Brian; Jay, Chadwick V.; Udevitz, Mark S.; Fischbach, Anthony S.

    2017-01-01

    Increased periods of sparse sea ice over the continental shelf of the Chukchi Sea in late summer have reduced offshore haulout habitat for Pacific walruses (Odobenus rosmarus divergens) and increased opportunities for human activities in the region. Knowing how many walruses could be affected by human activities would be useful to conservation decisions. Currently, there are no adequate estimates of walrus abundance in the northeastern Chukchi Sea during summer–early autumn. Estimating abundance in autumn might be possible from coastal surveys of hauled out walruses during periods when offshore sea ice is unavailable to walruses. We evaluated methods to estimate the size of the walrus population that was using a haulout on the coast of northwestern Alaska in autumn by using aerial photography to count the number of hauled out walruses (herd size) and data from 37 tagged walruses to estimate availability (proportion of population hauled out). We used two methods to estimate availability, direct proportions of hauled out tagged walruses and smoothed proportions using local polynomial regression. Point estimates of herd size (4200–38,000 walruses) and total population size (76,000–287,000 walruses) ranged widely among days and between the two methods of estimating availability. Estimates of population size were influenced most by variation in estimates of availability. Coastal surveys might be improved most by counting walruses when the greatest numbers are hauled out, thereby reducing the influence of availability on population size estimates. The chance of collecting data during peak haulout periods would be improved by conducting multiple surveys.

  7. Kinetic-theory predictions of clustering instabilities in granular flows: beyond the small-Knudsen-number regime

    Energy Technology Data Exchange (ETDEWEB)

    Mitrano, Peter P.; Zenk, John R.; Benyahia, Sofiane; Galvin, Janine E.; Dahl, Steven R.; Hrenya, Christine M.

    2013-12-04

    In this work we quantitatively assess, via instabilities, a Navier–Stokes-order (small- Knudsen-number) continuum model based on the kinetic theory analogy and applied to inelastic spheres in a homogeneous cooling system. Dissipative collisions are known to give rise to instabilities, namely velocity vortices and particle clusters, for sufficiently large domains. We compare predictions for the critical length scales required for particle clustering obtained from transient simulations using the continuum model with molecular dynamics (MD) simulations. The agreement between continuum simulations and MD simulations is excellent, particularly given the presence of well-developed velocity vortices at the onset of clustering. More specifically, spatial mapping of the local velocity-field Knudsen numbers (Knu) at the time of cluster detection reveals Knu » 1 due to the presence of large velocity gradients associated with vortices. Although kinetic-theory-based continuum models are based on a small- Kn (i.e. small-gradient) assumption, our findings suggest that, similar to molecular gases, Navier–Stokes-order (small-Kn) theories are surprisingly accurate outside their expected range of validity.

  8. Shear-induced clustering of Brownian colloids in associative polymer networks at moderate Péclet number

    Science.gov (United States)

    Kim, Juntae; Helgeson, Matthew E.

    2016-08-01

    We investigate shear-induced clustering and its impact on fluid rheology in polymer-colloid mixtures at moderate colloid volume fraction. By employing a thermoresponsive system that forms associative polymer-colloid networks, we present experiments of rheology and flow-induced microstructure on colloid-polymer mixtures in which the relative magnitudes of the time scales associated with relaxation of viscoelasticity and suspension microstructure are widely and controllably varied. In doing so, we explore several limits of relative magnitude of the relevant dimensionless shear rates, the Weissenberg number Wi and the Péclet number Pe. In all of these limits, we find that the fluid exhibits two distinct regimes of shear thinning at relatively low and high shear rates, in which the rheology collapses by scaling with Wi and Pe, respectively. Using three-dimensionally-resolved flow small-angle neutron scattering measurements, we observe clustering of the suspension above a critical shear rate corresponding to Pe ˜0.1 over a wide range of fluid conditions, having anisotropy with projected orientation along both the vorticity and compressional axes of shear. The degree of anisotropy is shown to scale with Pe. From this we formulate an empirical model for the shear stress and viscosity, in which the viscoelastic network stress is augmented by an asymptotic shear thickening contribution due to hydrodynamic clustering. Overall, our results elucidate the significant role of hydrodynamic interactions in contributing to shear-induced clustering of Brownian suspensions in viscoelastic liquids.

  9. Magic number behavior for heat capacities of medium sized classical Lennard-Jones clusters

    CERN Document Server

    Frantz, D D

    2001-01-01

    Monte Carlo methods were used to calculate heat capacities as functions of temperature for classical atomic clusters of aggregate sizes $25 \\leq N \\leq 60$ that were bound by pairwise Lennard-Jones potentials. The parallel tempering method was used to overcome convergence difficulties due to quasiergodicity in the solid-liquid phase-change regions. All of the clusters studied had pronounced peaks in their heat capacity curves, most of which corresponded to their solid-liquid phase-change regions. The heat capacity peak height and location exhibited two general trends as functions of cluster size: for $N = 25$ to 36, the peak temperature slowly increased, while the peak height slowly decreased, disappearing by $N = 37$; for $N = 30$, a very small secondary peak at very low temperature emerged and quickly increased in size and temperature as $N$ increased, becoming the dominant peak by $N = 36$. Superimposed on these general trends were smaller fluctuations in the peak heights that corresponded to ``magic numbe...

  10. Counting carbohydrates

    Science.gov (United States)

    Carb counting; Carbohydrate-controlled diet; Diabetic diet; Diabetes-counting carbohydrates ... Many foods contain carbohydrates (carbs), including: Fruit and fruit juice Cereal, bread, pasta, and rice Milk and milk products, soy milk Beans, legumes, ...

  11. Seal Counts

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Database of seal counts from aerial photography. Counts by image, site, species, and date are stored in the database along with information on entanglements and...

  12. Platelet Count

    Science.gov (United States)

    ... their spleen removed surgically Use of birth control pills (oral contraceptives) Some conditions may cause a temporary (transitory) increased ... increased platelet counts include estrogen and birth control pills (oral contraceptives). Mildly decreased platelet counts may be seen in ...

  13. Transradial Amputee Gesture Classification Using an Optimal Number of sEMG Sensors: An Approach Using ICA Clustering.

    Science.gov (United States)

    Naik, Ganesh R; Al-Timemy, Ali H; Nguyen, Hung T

    2016-08-01

    Surface electromyography (sEMG)-based pattern recognition studies have been widely used to improve the classification accuracy of upper limb gestures. Information extracted from multiple sensors of the sEMG recording sites can be used as inputs to control powered upper limb prostheses. However, usage of multiple EMG sensors on the prosthetic hand is not practical and makes it difficult for amputees due to electrode shift/movement, and often amputees feel discomfort in wearing sEMG sensor array. Instead, using fewer numbers of sensors would greatly improve the controllability of prosthetic devices and it would add dexterity and flexibility in their operation. In this paper, we propose a novel myoelectric control technique for identification of various gestures using the minimum number of sensors based on independent component analysis (ICA) and Icasso clustering. The proposed method is a model-based approach where a combination of source separation and Icasso clustering was utilized to improve the classification performance of independent finger movements for transradial amputee subjects. Two sEMG sensor combinations were investigated based on the muscle morphology and Icasso clustering and compared to Sequential Forward Selection (SFS) and greedy search algorithm. The performance of the proposed method has been validated with five transradial amputees, which reports a higher classification accuracy ( > 95%). The outcome of this study encourages possible extension of the proposed approach to real time prosthetic applications.

  14. Ribosomal DNA clusters and telomeric (TTAGG)n repeats in blue butterflies (Lepidoptera, Lycaenidae) with low and high chromosome numbers

    Science.gov (United States)

    Vershinina, Alisa O.; Anokhin, Boris A.; Lukhtanov, Vladimir A.

    2015-01-01

    Abstract Ribosomal DNA clusters and telomeric repeats are important parts of eukaryotic genome. However, little is known about their organization and localization in karyotypes of organisms with holocentric chromosomes. Here we present first cytogenetic study of these molecular structures in seven blue butterflies of the genus Polyommatus Latreille, 1804 with low and high chromosome numbers (from n=10 to n=ca.108) using fluorescence in situ hybridization (FISH) with 18S rDNA and (TTAGG)n telomeric probes. FISH with the 18S rDNA probe showed the presence of two different variants of the location of major rDNA clusters in Polyommatus species: with one or two rDNA-carrying chromosomes in haploid karyotype. We discuss evolutionary trends and possible mechanisms of changes in the number of ribosomal clusters. We also demonstrate that Polyommatus species have the classical insect (TTAGG)n telomere organization. This chromosome end protection mechanism probably originated de novo in small chromosomes that evolved via fragmentations. PMID:26140159

  15. Maximization of the Supportable Number of Sensors in QoS-Aware Cluster-Based Underwater Acoustic Sensor Networks

    Directory of Open Access Journals (Sweden)

    Thi-Tham Nguyen

    2014-03-01

    Full Text Available This paper proposes a practical low-complexity MAC (medium access control scheme for quality of service (QoS-aware and cluster-based underwater acoustic sensor networks (UASN, in which the provision of differentiated QoS is required. In such a network, underwater sensors (U-sensor in a cluster are divided into several classes, each of which has a different QoS requirement. The major problem considered in this paper is the maximization of the number of nodes that a cluster can accommodate while still providing the required QoS for each class in terms of the PDR (packet delivery ratio. In order to address the problem, we first estimate the packet delivery probability (PDP and use it to formulate an optimization problem to determine the optimal value of the maximum packet retransmissions for each QoS class. The custom greedy and interior-point algorithms are used to find the optimal solutions, which are verified by extensive simulations. The simulation results show that, by solving the proposed optimization problem, the supportable number of underwater sensor nodes can be maximized while satisfying the QoS requirements for each class.

  16. Maximization of the supportable number of sensors in QoS-aware cluster-based underwater acoustic sensor networks.

    Science.gov (United States)

    Nguyen, Thi-Tham; Le, Duc Van; Yoon, Seokhoon

    2014-03-07

    This paper proposes a practical low-complexity MAC (medium access control) scheme for quality of service (QoS)-aware and cluster-based underwater acoustic sensor networks (UASN), in which the provision of differentiated QoS is required. In such a network, underwater sensors (U-sensor) in a cluster are divided into several classes, each of which has a different QoS requirement. The major problem considered in this paper is the maximization of the number of nodes that a cluster can accommodate while still providing the required QoS for each class in terms of the PDR (packet delivery ratio). In order to address the problem, we first estimate the packet delivery probability (PDP) and use it to formulate an optimization problem to determine the optimal value of the maximum packet retransmissions for each QoS class. The custom greedy and interior-point algorithms are used to find the optimal solutions, which are verified by extensive simulations. The simulation results show that, by solving the proposed optimization problem, the supportable number of underwater sensor nodes can be maximized while satisfying the QoS requirements for each class.

  17. HerMES: A search for high-redshift dusty galaxies in the HerMES Large Mode Survey - Catalogue, number counts and early results

    CERN Document Server

    Asboth, V; Sayers, J; Bethermin, M; Chapman, S C; Clements, D L; Cooray, A; Dannerbauer, H; Farrah, D; Glenn, J; Golwala, S R; Halpern, M; Ibar, E; Ivison, R J; Maloney, P R; Marques-Chaves, R; Martinez-Navajas, P I; Oliver, S J; Perez-Fournon, I; Riechers, D A; Rowan-Robinson, M; Scott, Douglas; Siegel, S R; Vieira, J D; Viero, M; Wang, L; Wardlow, J; Wheeler, J

    2016-01-01

    Selecting sources with rising flux densities towards longer wavelengths from Herschel/SPIRE maps is an efficient way to produce a catalogue rich in high-redshift (z > 4) dusty star-forming galaxies. The effectiveness of this approach has already been confirmed by spectroscopic follow-up observations, but the previously available catalogues made this way are limited by small survey areas. Here we apply a map-based search method to 274 deg$^2$ of the HerMES Large Mode Survey (HeLMS) and create a catalogue of 477 objects with SPIRE flux densities $S_{500} > S_{350} >S_{250}$ and a 5 \\sigma cut-off $S_{500}$ > 52 mJy. From this catalogue we determine that the total number of these "red" sources is at least an order of magnitude higher than predicted by galaxy evolution models. These results are in agreement with previous findings in smaller HerMES fields; however, due to our significantly larger sample size we are also able to investigate the shape of the red source counts for the first time. We examine the 500 $...

  18. The SCUBA-2 Cosmology Legacy Survey: blank-field number counts of 450um-selected galaxies and their contribution to the cosmic infrared background

    CERN Document Server

    Geach, J E; Coppin, K E K; Dunlop, J S; Halpern, M; Smail, Ian; van der Werf, P; Serjeant, S; Farrah, D; Roseboom, I; Targett, T; Arumugam, V; Asboth, V; Blain, A; Chrysostomou, A; Clarke, C; Ivison, R J; Jones, S L; Karim, A; Mackenzie, T; Meijerink, R; Michalowski, M J; Scott, D; Simpson, J; Swinbank, A M; Alexander, D; Almaini, O; Aretxaga, I; Best, P; Chapman, S; Clements, D L; Conselice, C; Danielson, A L R; Eales, S; Edge, A C; Gibb, A; Hughes, D; Jenness, T; Knudsen, K K; Lacey, C; Marsden, G; McMahon, R; Oliver, S; Page, M J; Peacock, J A; Rigopoulou, D; Robson, E I; Spaans, M; Stevens, J; Webb, T M A; Willott, C; Wilson, C D; Zemcov, M

    2012-01-01

    The first deep blank-field 450um map (1-sigma~1.3mJy) from the SCUBA-2 Cosmology Legacy Survey (S2CLS), conducted with the James Clerk Maxwell Telescope (JCMT) is presented. Our map covers 140 arcmin^2 of the COSMOS field, in the footprint of the HST CANDELS area. Using 60 submillimetre galaxies (SMGs) detected at >3.75-sigma, we evaluate the number counts of 450um-selected galaxies with flux densities S_450>5mJy. The 8-arcsec JCMT beam and high sensitivity of SCUBA-2 now make it possible to directly resolve a larger fraction of the cosmic infrared background (CIB, peaking at ~200um) into the individual galaxies responsible for its emission than has previously been possible at this wavelength. At S_450>5mJy we resolve (7.4[+/-]0.7)x10^-2 MJy/sr of the CIB at 450um (equivalent to 16[+/-]7% of the absolute brightness measured by COBE at this wavelength) into point sources. A further ~40% of the CIB can be recovered through a statistical stack of 24um emitters in this field, indicating that the majority (~60%) o...

  19. HaplotypeCN: copy number haplotype inference with Hidden Markov Model and localized haplotype clustering.

    Directory of Open Access Journals (Sweden)

    Yen-Jen Lin

    Full Text Available Copy number variation (CNV has been reported to be associated with disease and various cancers. Hence, identifying the accurate position and the type of CNV is currently a critical issue. There are many tools targeting on detecting CNV regions, constructing haplotype phases on CNV regions, or estimating the numerical copy numbers. However, none of them can do all of the three tasks at the same time. This paper presents a method based on Hidden Markov Model to detect parent specific copy number change on both chromosomes with signals from SNP arrays. A haplotype tree is constructed with dynamic branch merging to model the transition of the copy number status of the two alleles assessed at each SNP locus. The emission models are constructed for the genotypes formed with the two haplotypes. The proposed method can provide the segmentation points of the CNV regions as well as the haplotype phasing for the allelic status on each chromosome. The estimated copy numbers are provided as fractional numbers, which can accommodate the somatic mutation in cancer specimens that usually consist of heterogeneous cell populations. The algorithm is evaluated on simulated data and the previously published regions of CNV of the 270 HapMap individuals. The results were compared with five popular methods: PennCNV, genoCN, COKGEN, QuantiSNP and cnvHap. The application on oral cancer samples demonstrates how the proposed method can facilitate clinical association studies. The proposed algorithm exhibits comparable sensitivity of the CNV regions to the best algorithm in our genome-wide study and demonstrates the highest detection rate in SNP dense regions. In addition, we provide better haplotype phasing accuracy than similar approaches. The clinical association carried out with our fractional estimate of copy numbers in the cancer samples provides better detection power than that with integer copy number states.

  20. HaplotypeCN: Copy Number Haplotype Inference with Hidden Markov Model and Localized Haplotype Clustering

    Science.gov (United States)

    Lin, Yen-Jen; Chen, Yu-Tin; Hsu, Shu-Ni; Peng, Chien-Hua; Tang, Chuan-Yi; Yen, Tzu-Chen; Hsieh, Wen-Ping

    2014-01-01

    Copy number variation (CNV) has been reported to be associated with disease and various cancers. Hence, identifying the accurate position and the type of CNV is currently a critical issue. There are many tools targeting on detecting CNV regions, constructing haplotype phases on CNV regions, or estimating the numerical copy numbers. However, none of them can do all of the three tasks at the same time. This paper presents a method based on Hidden Markov Model to detect parent specific copy number change on both chromosomes with signals from SNP arrays. A haplotype tree is constructed with dynamic branch merging to model the transition of the copy number status of the two alleles assessed at each SNP locus. The emission models are constructed for the genotypes formed with the two haplotypes. The proposed method can provide the segmentation points of the CNV regions as well as the haplotype phasing for the allelic status on each chromosome. The estimated copy numbers are provided as fractional numbers, which can accommodate the somatic mutation in cancer specimens that usually consist of heterogeneous cell populations. The algorithm is evaluated on simulated data and the previously published regions of CNV of the 270 HapMap individuals. The results were compared with five popular methods: PennCNV, genoCN, COKGEN, QuantiSNP and cnvHap. The application on oral cancer samples demonstrates how the proposed method can facilitate clinical association studies. The proposed algorithm exhibits comparable sensitivity of the CNV regions to the best algorithm in our genome-wide study and demonstrates the highest detection rate in SNP dense regions. In addition, we provide better haplotype phasing accuracy than similar approaches. The clinical association carried out with our fractional estimate of copy numbers in the cancer samples provides better detection power than that with integer copy number states. PMID:24849202

  1. Cosmological constraints from galaxy clustering and the mass-to-number ratio of galaxy clusters: marginalizing over the physics of galaxy formation

    Energy Technology Data Exchange (ETDEWEB)

    Reddick, Rachel M.; Wechsler, Risa H.; Lu, Yu [Kavli Institute for Particle Astrophysics and Cosmology, Physics Department, Stanford University, Stanford, CA 94305 (United States); Tinker, Jeremy L., E-mail: rmredd@stanford.edu, E-mail: rwechsler@stanford.edu [Center for Cosmology and Particle Physics, Department of Physics, New York University, New York, NY 10003 (United States)

    2014-03-10

    Many approaches to obtaining cosmological constraints rely on the connection between galaxies and dark matter. However, the distribution of galaxies is dependent on their formation and evolution as well as on the cosmological model, and galaxy formation is still not a well-constrained process. Thus, methods that probe cosmology using galaxies as tracers for dark matter must be able to accurately estimate the cosmological parameters. This can be done without knowing details of galaxy formation a priori as long as the galaxies are well represented by a halo occupation distribution (HOD). We apply this reasoning to the method of obtaining Ω {sub m} and σ{sub 8} from galaxy clustering combined with the mass-to-number ratio of galaxy clusters. To test the sensitivity of this method to variations due to galaxy formation, we consider several different models applied to the same cosmological dark matter simulation. The cosmological parameters are then estimated using the observables in each model, marginalizing over the parameters of the HOD. We find that for models where the galaxies can be well represented by a parameterized HOD, this method can successfully extract the desired cosmological parameters for a wide range of galaxy formation prescriptions.

  2. Galaxy Bias and Halo-Occupation Numbers from Large-Scale Clustering

    CERN Document Server

    Sefusatti, E; Sefusatti, Emiliano; Scoccimarro, Roman

    2005-01-01

    We show that current surveys have at least as much signal to noise in higher-order statistics as in the power spectrum at weakly nonlinear scales. We discuss how one can use this information to determine the mean of the galaxy halo occupation distribution (HOD) using only large-scale information, through galaxy bias parameters determined from the galaxy bispectrum and trispectrum. After introducing an averaged, reasonably fast to evaluate, trispectrum estimator, we show that the expected errors on linear and quadratic bias parameters can be reduced by at least 20-40%. Also, the inclusion of the trispectrum information, which is sensitive to "three-dimensionality" of structures, helps significantly in constraining the mass dependence of the HOD mean. Our approach depends only on adequate modeling of the abundance and large-scale clustering of halos and thus is independent of details of how galaxies are distributed within halos. This provides a consistency check on the traditional approach of using two-point st...

  3. Quantifying the impact of community quarantine on SARS transmission in Ontario: estimation of secondary case count difference and number needed to quarantine

    Directory of Open Access Journals (Sweden)

    Laflèche Julie ML

    2009-12-01

    Full Text Available Abstract Background Community quarantine is controversial, and the decision to use and prepare for it should be informed by specific quantitative evidence of benefit. Case-study reports on 2002-2004 SARS outbreaks have discussed the role of quarantine in the community in transmission. However, this literature has not yielded quantitative estimates of the reduction in secondary cases attributable to quarantine as would be seen in other areas of health policy and cost-effectiveness analysis. Methods Using data from the 2003 Ontario, Canada, SARS outbreak, two novel expressions for the impact of quarantine are presented. Secondary Case Count Difference (SCCD reflects reduction in the average number of transmissions arising from a SARS case in quarantine, relative to not in quarantine, at onset of symptoms. SCCD was estimated using Poisson and negative binomial regression models (with identity link function comparing the number of secondary cases to each index case for quarantine relative to non-quarantined index cases. The inverse of this statistic is proposed as the number needed to quarantine (NNQ to prevent one additional secondary transmission. Results Our estimated SCCD was 0.133 fewer secondary cases per quarantined versus non-quarantined index case; and a NNQ of 7.5 exposed individuals to be placed in community quarantine to prevent one additional case of transmission in the community. This analysis suggests quarantine can be an effective preventive measure, although these estimates lack statistical precision. Conclusions Relative to other health policy areas, literature on quarantine tends to lack in quantitative expressions of effectiveness, or agreement on how best to report differences in outcomes attributable to control measure. We hope to further this discussion through presentation of means to calculate and express the impact of population control measures. The study of quarantine effectiveness presents several methodological and

  4. Objects, Numbers, Fingers, Space: Clustering of Ventral and Dorsal Functions in Young Children and Adults

    Science.gov (United States)

    Chinello, Alessandro; Cattani, Veronica; Bonfiglioli, Claudia; Dehaene, Stanislas; Piazza, Manuela

    2013-01-01

    In the primate brain, sensory information is processed along two partially segregated cortical streams: the ventral stream, mainly coding for objects' shape and identity, and the dorsal stream, mainly coding for objects' quantitative information (including size, number, and spatial position). Neurophysiological measures indicate that such…

  5. Objects, Numbers, Fingers, Space: Clustering of Ventral and Dorsal Functions in Young Children and Adults

    Science.gov (United States)

    Chinello, Alessandro; Cattani, Veronica; Bonfiglioli, Claudia; Dehaene, Stanislas; Piazza, Manuela

    2013-01-01

    In the primate brain, sensory information is processed along two partially segregated cortical streams: the ventral stream, mainly coding for objects' shape and identity, and the dorsal stream, mainly coding for objects' quantitative information (including size, number, and spatial position). Neurophysiological measures indicate that such…

  6. Calculating the number of cluster heads based on the rate-distortion function in wireless sensor networks.

    Science.gov (United States)

    Yang, Mingxin; He, Jingsha; Zhang, Yuqiang

    2014-01-01

    Due to limited resources in wireless sensor nodes, energy efficiency is considered as one of the primary constraints in the design of the topology of wireless sensor networks (WSNs). Since data that are collected by wireless sensor nodes exhibit the characteristics of temporal association, data fusion has also become a very important means of reducing network traffic as well as eliminating data redundancy as far as data transmission is concerned. Another reason for data fusion is that, in many applications, only some of the data that are collected can meet the requirements of the sink node. In this paper, we propose a method to calculate the number of cluster heads or data aggregators during data fusion based on the rate-distortion function. In our discussion, we will first establish an energy consumption model and then describe a method for calculating the number of cluster heads from the point of view of reducing energy consumption. We will also show through theoretical analysis and experimentation that the network topology design based on the rate-distortion function is indeed more energy-efficient.

  7. Calculating the Number of Cluster Heads Based on the Rate-Distortion Function in Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Mingxin Yang

    2014-01-01

    Full Text Available Due to limited resources in wireless sensor nodes, energy efficiency is considered as one of the primary constraints in the design of the topology of wireless sensor networks (WSNs. Since data that are collected by wireless sensor nodes exhibit the characteristics of temporal association, data fusion has also become a very important means of reducing network traffic as well as eliminating data redundancy as far as data transmission is concerned. Another reason for data fusion is that, in many applications, only some of the data that are collected can meet the requirements of the sink node. In this paper, we propose a method to calculate the number of cluster heads or data aggregators during data fusion based on the rate-distortion function. In our discussion, we will first establish an energy consumption model and then describe a method for calculating the number of cluster heads from the point of view of reducing energy consumption. We will also show through theoretical analysis and experimentation that the network topology design based on the rate-distortion function is indeed more energy-efficient.

  8. Blood Count Tests

    Science.gov (United States)

    Your blood contains red blood cells (RBC), white blood cells (WBC), and platelets. Blood count tests measure the number and types of cells in your blood. This helps doctors check on your overall health. ...

  9. Analyzing indirect effects in cluster randomized trials. The effect of estimation method, number of groups and group sizes on accuracy and power.

    Directory of Open Access Journals (Sweden)

    Joop eHox

    2014-02-01

    Full Text Available Cluster randomized trials assess the effect of an intervention that is carried out at the group or cluster level. Ajzen’s theory of planned behaviour is often used to model the effect of the intervention as an indirect effect mediated in turn by attitude, norms and behavioural intention. Structural equation modelling (SEM is the technique of choice to estimate indirect effects and their significance. However, this is a large sample technique, and its application in a cluster randomized trial assumes a relatively large number of clusters. In practice, the number of clusters in these studies tends to be relatively small, e.g. much less than fifty. This study uses simulation methods to find the lowest number of clusters needed when multilevel SEM is used to estimate the indirect effect. Maximum likelihood estimation is compared to Bayesian analysis, with the central quality criteria being accuracy of the point estimate and the confidence interval. We also investigate the power of the test for the indirect effect. We conclude that Bayes estimation works well with much smaller cluster level sample sizes such as 20 cases than maximum likelihood estimation; although the bias is larger the coverage is much better. When only 5 to 10 clusters are available per treatment condition even with Bayesian estimation problems occur.

  10. The Role of Vision in the Development of Finger-Number Interactions: Finger-Counting and Finger-Montring in Blind Children

    Science.gov (United States)

    Crollen, Virginie; Mahe, Rachel; Collignon, Olivier; Seron, Xavier

    2011-01-01

    Previous research has suggested that the use of the fingers may play a functional role in the development of a mature counting system. However, the role of developmental vision in the elaboration of a finger numeral representation remains unexplored. In the current study, 14 congenitally blind children and 14 matched sighted controls undertook…

  11. A Model Comparison for Count Data with a Positively Skewed Distribution with an Application to the Number of University Mathematics Courses Completed

    Science.gov (United States)

    Liou, Pey-Yan

    2009-01-01

    The current study examines three regression models: OLS (ordinary least square) linear regression, Poisson regression, and negative binomial regression for analyzing count data. Simulation results show that the OLS regression model performed better than the others, since it did not produce more false statistically significant relationships than…

  12. Determining the number of clusters for kernelized fuzzy C-means algorithms for automatic medical image segmentation

    Directory of Open Access Journals (Sweden)

    E.A. Zanaty

    2012-03-01

    Full Text Available In this paper, we determine the suitable validity criterion of kernelized fuzzy C-means and kernelized fuzzy C-means with spatial constraints for automatic segmentation of magnetic resonance imaging (MRI. For that; the original Euclidean distance in the FCM is replaced by a Gaussian radial basis function classifier (GRBF and the corresponding algorithms of FCM methods are derived. The derived algorithms are called as the kernelized fuzzy C-means (KFCM and kernelized fuzzy C-means with spatial constraints (SKFCM. These methods are implemented on eighteen indexes as validation to determine whether indexes are capable to acquire the optimal clusters number. The performance of segmentation is estimated by applying these methods independently on several datasets to prove which method can give good results and with which indexes. Our test spans various indexes covering the classical and the rather more recent indexes that have enjoyed noticeable success in that field. These indexes are evaluated and compared by applying them on various test images, including synthetic images corrupted with noise of varying levels, and simulated volumetric MRI datasets. Comparative analysis is also presented to show whether the validity index indicates the optimal clustering for our datasets.

  13. Multiplicity Counting

    Energy Technology Data Exchange (ETDEWEB)

    Geist, William H. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-12-01

    This set of slides begins by giving background and a review of neutron counting; three attributes of a verification item are discussed: 240Pueff mass; α, the ratio of (α,n) neutrons to spontaneous fission neutrons; and leakage multiplication. It then takes up neutron detector systems – theory & concepts (coincidence counting, moderation, die-away time); detector systems – some important details (deadtime, corrections); introduction to multiplicity counting; multiplicity electronics and example distributions; singles, doubles, and triples from measured multiplicity distributions; and the point model: multiplicity mathematics.

  14. Reticulocyte count

    Science.gov (United States)

    ... radiation therapy, or infection) Cirrhosis of the liver Anemia caused by low iron levels, or low levels of vitamin B12 or folate Chronic kidney disease Reticulocyte count may be higher during pregnancy.

  15. Influence of Heat Shock Temperatures and Fast Freezing on Viability of Probiotic Sporeformers and the Issue of Spore Plate Count Versus True Numbers

    Directory of Open Access Journals (Sweden)

    Mojtaba Jafari

    2016-02-01

    Full Text Available Background and Objectives: The purpose of the present study was to investigate effects of various heat shock conditions and fast freezing and subsequent thawing on the viability and recovery of Bacillus coagulans and Bacillus subtilis as probiotic sporeformers, and also to compare spore plate and microscopic counts. Materials and Methods: After preparing the final suspensions of B. coagulans and Bacillus subtilis subsp. Natto spores, they were spread-plated before and after fast freezing treatment (-70°C for about 1 min. Heat shock treatments of the spores were carried out at 68oC for 15, 20, and 30 min as well as at 80oC for 10 and 15 min. Concentrations of the examined probiotic sporeformers were determined simultaneously by plate enumerations and microscopically determined counts. Student’s t-test and one-way analysis of variance (ANOVA of SPSS were used for statistical analysis of the data. Analysis of DoE results was carried out using Minitab. Results: The results presented here show that the highest recovery rates for B. coagulans (14.75 log CFU/mL and B. subtilis spores (14.80 log CFU/mL were under a heat shock condition of 68°C for 20 min in nutrient agar (p<0.05. In addition, the survival rates of B. coagulans and B. subtilis spores under the fast freezing and subsequent thawing condition were about 90% and 88%, respectively. Plate counts differed significantly from counts determined microscopically, with differences of almost 0.5 and 0.8 log for B. coagulans and B. subtilis spores, respectively (p<0.05. In addition, DoE results of the study revealed that both factors of spore count method and only freezing factor in fast freezing treatment have a significant effect on concentrations of the spores examined (p<0.05. Conclusions: Heat shock conditions, freezing and subsequent thawing circumstances, and plate counts or enumerations determined microscopically have significant influences on the viability of probiotic sporeformers and

  16. Sublattice Counting and Orbifolds

    CERN Document Server

    Hanany, Amihay; Reffert, Susanne

    2010-01-01

    Abelian orbifolds of C^3 are known to be encoded by hexagonal brane tilings. To date it is not known how to count all such orbifolds. We fill this gap by employing number theoretic techniques from crystallography, and by making use of Polya's Enumeration Theorem. The results turn out to be beautifully encoded in terms of partition functions and Dirichlet Series. The same methods apply to counting orbifolds of any toric non-compact Calabi-Yau singularity. As additional examples, we count the orbifolds of the conifold, of the L^{aba} theories, and of C^4.

  17. Counting curves on surfaces

    OpenAIRE

    2015-01-01

    In this paper we consider an elementary, and largely unexplored, combinatorial problem in low-dimensional topology. Consider a real 2-dimensional compact surface $S$, and fix a number of points $F$ on its boundary. We ask: how many configurations of disjoint arcs are there on $S$ whose boundary is $F$? We find that this enumerative problem, counting curves on surfaces, has a rich structure. For instance, we show that the curve counts obey an effective recursion, in the general framework of to...

  18. Understanding Blood Counts

    Science.gov (United States)

    ... Lab and Imaging Tests Understanding Blood Counts Understanding Blood Counts Understanding Blood Counts SHARE: Print Glossary Blood cell counts give ... your blood that's occupied by red cells. Normal Blood Counts Normal blood counts fall within a range ...

  19. White Blood Cell Count

    Science.gov (United States)

    ... limited. Home Visit Global Sites Search Help? White Blood Cell Count Share this page: Was this page helpful? ... Count; Leukocyte Count; White Count Formal name: White Blood Cell Count Related tests: Complete Blood Count , Blood Smear , ...

  20. Tuning optical properties of magic number cluster (SiO2)4O2H4 by substitutional bonding with gold atoms.

    Science.gov (United States)

    Cai, Xiulong; Zhang, Peng; Ma, Liuxue; Zhang, Wenxian; Ning, Xijing; Zhao, Li; Zhuang, Jun

    2009-04-30

    By bonding gold atoms to the magic number cluster (SiO(2))(4)O(2)H(4), two groups of Au-adsorbed shell-like clusters Au(n)(SiO(2))(4)O(2)H(4-n) (n = 1-4) and Au(n)(SiO(2))(4)O(2) (n = 5-8) were obtained, and their spectral properties were studied. The ground-state structures of these clusters were optimized by density functional theory, and the results show that in despite of the different numbers and types of the adsorbed Au atoms, the cluster core (SiO(2))(4)O(2) of T(d) point-group symmetry keeps almost unchanged. The absorption spectra were obtained by time-dependent density functional theory. From one group to the other, an extension of absorption wavelength from the UV-visible to the NIR region was observed, and in each group the absorption strengths vary linearly with the number of Au atoms. These features indicate their advantages for exploring novel materials with easily controlled tunable optical properties. Furthermore, due to the weak electronic charge transfer between the Au atoms, the clusters containing Au(2) dimers, especially Au(8)(SiO(2))(4)O(2), absorb strongly NIR light at 900 approximately 1200 nm. Such strong absorption suggests potential applications of these shell-like clusters in tumor cells thermal therapy, like the gold-coated silica nanoshells with larger sizes.

  1. Counting Penguins.

    Science.gov (United States)

    Perry, Mike; Kader, Gary

    1998-01-01

    Presents an activity on the simplification of penguin counting by employing the basic ideas and principles of sampling to teach students to understand and recognize its role in statistical claims. Emphasizes estimation, data analysis and interpretation, and central limit theorem. Includes a list of items for classroom discussion. (ASK)

  2. Counting Populations

    Science.gov (United States)

    Damonte, Kathleen

    2004-01-01

    Scientists use sampling to get an estimate of things they cannot easily count. A population is made up of all the organisms of one species living together in one place at the same time. All of the people living together in one town are considered a population. All of the grasshoppers living in a field are a population. Scientists keep track of the…

  3. Galactic Extinction and Reddening from the South Galactic Cap u-band Sky Survey: u-band Galaxy Number Counts and u ‑ r  Color Distribution

    Science.gov (United States)

    Li, Linlin; Shen, Shiyin; Hou, Jinliang; Yuan, Fangting; Zhong, Jing; Zou, Hu; Zhou, Xu; Jiang, Zhaoji; Peng, Xiyan; Fan, Dongwei; Fan, Xiaohui; Fan, Zhou; He, Boliang; Jing, Yipeng; Lesser, Michael; Li, Cheng; Ma, Jun; Nie, Jundan; Wang, Jiali; Wu, Zhenyu; Zhang, Tianmeng; Zhou, Zhimin

    2017-02-01

    We study the integral Galactic extinction and reddening based on the galaxy catalog of the South Galactic Cap u-band Sky Survey (SCUSS), where u-band galaxy number counts and u ‑ r color distribution are used to derive the Galactic extinction and reddening respectively. We compare these independent statistical measurements with the reddening map of Schlegel et al. (SFD) and find that both the extinction and reddening from the number counts and color distribution are in good agreement with the SFD results at low extinction regions (E{(B-V)}{SFD}extinction regions (E{(B-V)}{SFD}> 0.12 mag), the SFD map overestimates the Galactic reddening systematically, which can be approximated by a linear relation {{Δ }}E{(B-V)=0.43[E(B-V)}{SFD}-0.12]. By combining the results from galaxy number counts and color distribution, we find that the shape of the Galactic extinction curve is in good agreement with the standard RV = 3.1 extinction law of O’Donnell.

  4. HerMES: deep number counts at 250, 350, and 500 microns in the COSMOS and GOODS-N fields and the build-up of the cosmic infrared background

    CERN Document Server

    Béthermin, M; Ilbert, O; Conley, A; Lagache, G; Amblard, A; Arumugam, V; Aussel, H; Berta, S; Bock, J; Boselli, A; Buat, V; Casey, C M; Castro-Rodríguez, N; Cava, A; Clements, D L; Cooray, A; Dowell, C D; Eales, S; Farrah, D; Franceschini, A; Glenn, J; Griffin, M; Hatziminaoglou, E; Heinis, S; Ibar, E; Ivison, R J; Kartaltepe, J S; Levenson, L; Magdis, G; Marchetti, L; Marsden, G; Nguyen, H T; O'Halloran, B; Oliver, S J; Omont, A; Page, M J; Panuzzo, P; Papageorgiou, A; Pearson, C P; Pérez-Fournon, I; Pohlen, M; Rigopoulou, D; Roseboom, I G; Rowan-Robinson, M; Salvato, M; Schulz, B; Scott, Douglas; Seymour, N; Shupe, D L; Smith, A J; Symeonidis, M; Trichas, M; Tugwell, K E; Vaccari, M; Valtchanov, I; Vieira, J D; Viero, M; Wang, L; Xu, C K; Zemcov, M

    2012-01-01

    ABRIGED Herschel/SPIRE has provided confusion limited maps of deep fields at 250, 350, and 500um, as part of the HerMES survey. Due to confusion, only a small fraction of the Cosmic Infrared Background can be resolved into individually-detected sources. Our goal is to produce deep galaxy number counts and redshift distributions below the confusion limit, which we then use to place strong constraints on the origins of the cosmic infrared background and on models of galaxy evolution. We individually extracted the bright SPIRE with a method using the positions, the flux densities, and the redshifts of the 24um sources as a prior, and derived the number counts and redshift distributions of the bright SPIRE sources. For fainter SPIRE sources, we reconstructed the number counts and the redshift distribution below the confusion limit using the deep 24um catalogs associated with photometric redshift and information provided by the stacking of these sources into the deep SPIRE maps. Finally, by integrating all these c...

  5. Iron-centered ten-vertex germanium clusters: the ubiquity of low energy pentagonal prismatic structures with various skeletal electron counts.

    Science.gov (United States)

    Uţă, M M; Cioloboc, D; King, R B

    2012-09-13

    One of the most significant recent developments (in 2009) is the discovery of the clusters M@Ge10(3-) (M = Fe, Co) in which the outer Ge10 polyhedron is a pentagonal prism rather than a deltahedral structure of the type predicted by the Wade-Mingos rules. Consistent with this experimental observation, density functional theory shows the lowest energy structures to be pentagonal prisms for the iron-centered clusters Fe@Ge10(z) in all nine charge states ranging from -5 to +3. This contrasts with the previously studied cobalt-centered germanium clusters Co@Ge10(z) for which the lowest energy structures are pentagonal prisms only for the electron richest systems where z ranges from -3 to -5. The C3v structures derived from the tetracapped trigonal prism found as lowest energy structures of the electron poorer Co@Ge10(z) (z = 0, -1, -2) systems are higher energy structures for the iron-centered germanium clusters Fe@Ge10(z) (z = 0, -1, -2). The strong energetic preference for pentagonal prismatic structures in the Fe@Ge10(z) clusters can be attributed to the need for the larger volume of the pentagonal prism relative to other 10-vertex closed polyhedra to accommodate the interstitial iron atom.

  6. Pedestrian Counting with Occlusion Handling Using Stereo Thermal Cameras

    Directory of Open Access Journals (Sweden)

    Miklas S. Kristoffersen

    2016-01-01

    Full Text Available The number of pedestrians walking the streets or gathered in public spaces is a valuable piece of information for shop owners, city governments, event organizers and many others. However, automatic counting that takes place day and night is challenging due to changing lighting conditions and the complexity of scenes with many people occluding one another. To address these challenges, this paper introduces the use of a stereo thermal camera setup for pedestrian counting. We investigate the reconstruction of 3D points in a pedestrian street with two thermal cameras and propose an algorithm for pedestrian counting based on clustering and tracking of the 3D point clouds. The method is tested on two five-minute video sequences captured at a public event with a moderate density of pedestrians and heavy occlusions. The counting performance is compared to the manually annotated ground truth and shows success rates of 95.4% and 99.1% for the two sequences.

  7. Near-Infrared Properties of Moderate-Redshift Galaxy Clusters: Halo Occupation Number, Mass-to-Light Ratios and Omega(M)

    Energy Technology Data Exchange (ETDEWEB)

    Muzzin, Adam; Yee, H.K.C.; /Toronto U., Astron. Dept.; Hall, Patrick B.; /York U., Canada; Lin, Huan; /Fermilab

    2007-03-01

    Using K-band imaging for 15 of the Canadian Network for Observational Cosmology (CNOC1) clusters we examine the near-infrared properties of moderate-redshift (0.19 < z < 0.55) galaxy clusters. We find that the number of K-band selected cluster galaxies within R{sub 500} (the Halo Occupation Number, HON) is well-correlated with the cluster dynamical mass (M{sub 500}) and X-ray Temperature (T{sub x}); however, the intrinsic scatter in these scaling relations is 37% and 46% respectively. Comparison with clusters in the local universe shows that the HON-M{sub 500} relation does not evolve significantly between z = 0 and z {approx} 0.3. This suggests that if dark matter halos are disrupted or undergo significant tidal-stripping in high-density regions as seen in numerical simulations, the stellar mass within the halos is tightly bound, and not removed during the process. The total K-band cluster light (L{sub 200},K) and K-band selected richness (parameterized by B{sub gc,K}) are also correlated with both the cluster T{sub x} and M{sub 200}. The total (intrinsic) scatter in the L{sub 200,K}-M{sub 200} and B{sub gc,K}-M{sub 200} relations are 43%(31%) and 35%(18%) respectively and indicates that for massive clusters both L{sub 200,K} and B{sub gc,K} can predict M{sub 200} with similar accuracy as T{sub x}, L{sub x} or optical richness (B{sub gc}). Examination of the mass-to-light ratios of the clusters shows that similar to local clusters, the K-band mass-to-light ratio is an increasing function of halo mass. Using the K-band mass-to-light ratios of the clusters, we apply the Oort technique and find {Omega}{sub m,0} = 0.22 {+-} 0.02, which agrees well with recent combined concordance cosmology parameters, but, similar to previous cluster studies, is on the low-density end of preferred values.

  8. The Growing Number of Kids in Severely Distressed Neighborhoods: Evidence from the 2000 Census. A Kids Count/PRB Report on Census 2000.

    Science.gov (United States)

    O'Hare, William; Mather, Mark

    Between 1990-2000, there was a decrease in the number of children living in high-poverty neighborhoods, but the picture provided by the decrease in poverty levels alone is incomplete and potentially misleading. Using a more comprehensive measure of neighborhood quality, researchers found that the number of children living in severely distressed…

  9. [Blood Count Specimen].

    Science.gov (United States)

    Tamura, Takako

    2015-12-01

    The circulating blood volume accounts for 8% of the body weight, of which 45% comprises cellular components (blood cells) and 55% liquid components. We can measure the number and morphological features of blood cells (leukocytes, red blood cells, platelets), or count the amount of hemoglobin in a complete blood count: (CBC). Blood counts are often used to detect inflammatory diseases such as infection, anemia, a bleeding tendency, and abnormal cell screening of blood disease. This count is widely used as a basic data item of health examination. In recent years, clinical tests before consultation have become common among outpatient clinics, and the influence of laboratory values on consultation has grown. CBC, which is intended to count the number of raw cells and to check morphological features, is easily influenced by the environment, techniques, etc., during specimen collection procedures and transportation. Therefore, special attention is necessary to read laboratory data. Providing correct test values that accurately reflect a patient's condition from the laboratory to clinical side is crucial. Inappropriate medical treatment caused by erroneous values resulting from altered specimens should be avoided. In order to provide correct test values, the daily management of devices is a matter of course, and comprehending data variables and positively providing information to the clinical side are important. In this chapter, concerning sampling collection, blood collection tubes, dealing with specimens, transportation, and storage, I will discuss their effects on CBC, along with management or handling methods.

  10. Clustering of Tuberculosis Cases Based on Variable-Number Tandem-Repeat Typing in Relation to the Population Structure of Mycobacterium tuberculosis in the Netherlands

    NARCIS (Netherlands)

    Sloot, R.; Borgdorff, M.W.; Beer, J.L. de; Ingen, J. van; Supply, P.; Soolingen, D. van

    2013-01-01

    The population structure of 3,776 Mycobacterium tuberculosis isolates was determined using variable-number tandem-repeat (VNTR) typing. The degree of clonality was so high that a more relaxed definition of clustering cannot be applied. Among recent immigrants with non-Euro-American isolates, transmi

  11. Galaxy Populations in Massive Galaxy Clusters to z = 1.1: Color Distribution, Concentration, Halo Occupation Number and Red Sequence Fraction

    Science.gov (United States)

    Hennig, C.; Mohr, J. J.; Zenteno, A.; Desai, S.; Dietrich, J. P.; Bocquet, S.; Strazzullo, V.; Saro, A.; Abbott, T. M. C.; Abdalla, F. B.; Bayliss, M.; Benoit-Lévy, A.; Bernstein, R. A.; Bertin, E.; Brooks, D.; Capasso, R.; Capozzi, D.; Carnero, A.; Kind, M. Carrasco; Carretero, J.; Chiu, I.; D'Andrea, C. B.; daCosta, L. N.; Diehl, H. T.; Doel, P.; Eifler, T. F.; Evrard, A. E.; Fausti-Neto, A.; Fosalba, P.; Frieman, J.; Gangkofner, C.; Gonzalez, A.; Gruen, D.; Gruendl, R. A.; Gupta, N.; Gutierrez, G.; Honscheid, K.; Hlavacek-Larrondo, J.; James, D. J.; Kuehn, K.; Kuropatkin, N.; Lahav, O.; March, M.; Marshall, J. L.; Martini, P.; McDonald, M.; Melchior, P.; Miller, C. J.; Miquel, R.; Neilsen, E.; Nord, B.; Ogando, R.; Plazas, A. A.; Reichardt, C.; Romer, A. K.; Rozo, E.; Rykoff, E. S.; Sanchez, E.; Santiago, B.; Schubnell, M.; Sevilla-Noarbe, I.; Smith, R. C.; Soares-Santos, M.; Sobreira, F.; Stalder, B.; Stanford, S. A.; Suchyta, E.; Swanson, M. E. C.; Tarle, G.; Thomas, D.; Vikram, V.; Walker, A. R.; Zhang, Y.

    2017-01-01

    We study the galaxy populations in 74 Sunyaev Zeldovich Effect (SZE) selected clusters from the South Pole Telescope (SPT) survey that have been imaged in the science verification phase of the Dark Energy Survey (DES). The sample extends up to z ˜ 1.1 with 4 × 1014M⊙ ≤ M200 ≤ 3 × 1015M⊙. Using the band containing the 4000 Å break and its redward neighbor, we study the color-magnitude distributions of cluster galaxies to ˜m★ + 2, finding: (1) the intrinsic rest frame g - r color width of the red sequence (RS) population is ˜0.03 out to z ˜ 0.85 with a preference for an increase to ˜0.07 at z = 1 and (2) the prominence of the RS declines beyond z ˜ 0.6. The spatial distribution of cluster galaxies is well described by the NFW profile out to 4R200 with a concentration of cg = 3.59^{+0.20}_{-0.18}, 5.37^{+0.27}_{-0.24} and 1.38^{+0.21}_{-0.19} for the full, the RS and the blue non-RS populations, respectively, but with ˜40% to 55% cluster to cluster variation and no statistically significant redshift or mass trends. The number of galaxies within the virial region N200 exhibits a mass trend indicating that the number of galaxies per unit total mass is lower in the most massive clusters, and shows no significant redshift trend. The red sequence (RS) fraction within R200 is (68 ± 3)% at z = 0.46, varies from ˜55% at z = 1 to ˜80% at z = 0.1, and exhibits intrinsic variation among clusters of ˜14%. We discuss a model that suggests the observed redshift trend in RS fraction favors a transformation timescale for infalling field galaxies to become RS galaxies of 2 to 3 Gyr.

  12. Counting Possibilia

    Directory of Open Access Journals (Sweden)

    Alfredo Tomasetta

    2010-06-01

    Full Text Available Timothy Williamson supports the thesis that every possible entity necessarily exists and so he needs to explain how a possible son of Wittgenstein’s, for example, exists in our world:he exists as a merely possible object (MPO, a pure locus of potential. Williamson presents a short argument for the existence of MPOs: how many knives can be made by fitting together two blades and two handles? Four: at the most two are concrete objects, the others being merely possible knives and merely possible objects. This paper defends the idea that one can avoid reference and ontological commitment to MPOs. My proposal is that MPOs can be dispensed with by using the notion of rules of knife-making. I first present a solution according to which we count lists of instructions - selected by the rules - describing physical combinations between components. This account, however, has its own difficulties and I eventually suggest that one can find a way out by admitting possible worlds, entities which are more commonly accepted - at least by philosophers - than MPOs. I maintain that, in answering Williamson’s questions, we count classes of physically possible worlds in which the same instance of a general rule is applied.

  13. Synthesis, structure, and magnetic studies of manganese-oxygen clusters of reduced coordination number, featuring an unchelated, 5-coordinate octanuclear manganese cluster with water-derived oxo ligands.

    Science.gov (United States)

    Kondaveeti, Sandeep K; Vaddypally, Shivaiah; Lam, Carol; Hirai, Daigorou; Ni, Ni; Cava, Robert J; Zdilla, Michael J

    2012-10-01

    The synthesis of reduced coordination (less than 6), unchelated manganese oxygen cluster systems is described. Addition of phenols to Mn(NR(2))(2) (R = SiMe(3)) results in protolytic amide ligand replacement, and represents the primary entry into the described chemistry. Addition of PhOH to Mn(NR(2))(2) results in the formation of the heteroleptic dimer Mn(2)(μ-OPh)(2)(NR(2))(2)(THF)(2) (1). Usage of the sterically larger 2,6-diphenylphenol (Ph(2)C(6)H(3)OH) as the ligand source results in the formation of a 3-coordinate heteroleptic dimer without THF coordination, Mn(2)(μ-OC(6)H(3)Ph(2))(2)(NR(2))(2) (2). Attempts to generate 2 in the presence of THF or Et(2)O resulted in isolation of monomeric Mn(OC(6)H(3)Ph(2))(2)L(2) (3, L = THF, Et(2)O). Use of the sterically intermediate 2,4,6-trimethylphenol (MesOH) resulted in formation of the linear trinuclear cluster Mn(3)(μ-OMes)(4)(NR(2))(2)(THF)(2) (4). Reaction of Mn(NR(2))(2) with PhOH in the presence of water, or reaction of 1 with water, results in the formation of a 5-coordinate, unchelated Mn-O cluster, Mn(8)(μ(5)-O)(2)(μ-OPh)(12)(THF)(6) (5). Preparation, structures, steric properties, and magnetic properties are presented. Notably, complex 5 exhibits a temperature-dependent phase transition between a 4-spin paramagnetic system at low temperature, and an 8-spin paramagnetic system at room temperature.

  14. Single particle counting diagnostic system for measuring fine particulates at high number densities in research and industrial applications. Final report summarizing instrument development, validation and operating instructions

    Energy Technology Data Exchange (ETDEWEB)

    Holve, D.J.

    1983-10-01

    Optical methods for particle size distribution measurements in practical high temperature environments have achieved feasibility and offer significant advantages over conventional sampling methods. The present report describes a mobile electro-optical system which has been designed for general use in a wide range of research and industrial environments. Specific features of this system include a method of providing in situ alignment and incorporation of an extinction measurement for application to optically thick aerosol flows. The instrument has demonstrated capability for measuring individual particles in the size range 0.25 to 100 microns at number densities up to 10/sup 12//m/sup 3/. In addition to demonstration of the system's wide dynamic range, we show the utility of the in situ alignment method in hot (1100 K) turbulent flows where beam steering can be a problem. As an example of the instrument's application, number and mass frequency distribution measurements of flyash and pulverized coal obtained in an atmospheric combustion exhaust simulator show that the raw pulverized coal contains large numbers of submicron particles similar to the flyash formed after combustion.

  15. Counting quasar--radio source pairs to derive the millijansky radio luminosity function and clustering strength to z=3.5

    CERN Document Server

    Fine, S; Johnston, R; Jarvis, M J; Mauch, T

    2015-01-01

    We apply a cross-correlation technique to infer the $S>3$mJy radio luminosity function (RLF) from the NRAO VLA sky survey (NVSS) to $z\\sim3.5$. We measure $\\Sigma$ the over density of radio sources around spectroscopically confirmed quasars. $\\Sigma$ is related to the space density of radio sources at the distance of the quasars and the clustering strength between the two samples, hence knowledge of one constrains the other. Under simple assumptions we find $\\Phi\\propto (1+z)^{3.7\\pm0.7}$ out to $z\\sim2$. Above this redshift the evolution slows and we constrain the evolution exponent to $<1.01$ ($2\\sigma$). This behaviour is almost identical to that found by previous authors for the bright end of the RLF potentially indicating that we are looking at the same population. This suggests that the NVSS is dominated by a single population; most likely radio sources associated with high-excitation cold-mode accretion. Inversely, by adopting a previously modelled RLF we can constrain the clustering of high-redshif...

  16. Cluster Analysis of World's Airports on the Basis of Number of Passengers Handled (Case Study Examinning the Impact of Significant Events

    Directory of Open Access Journals (Sweden)

    Marta Žambochová

    2017-03-01

    Full Text Available Nowadays, the air transportation is one of key means of transport. Unfortunately, there are many factors influencing its popularity and intensity of its use. There are many studies investigating these factors. The paper investigates the possibility of classifying the world's airports in terms of the trend in the number of handled passengers as it is one of the main economic indicators for airports. For this classification we chose cluster analysis. The paper focuses on an important aspect of the process, which chooses the appropriate number of clusters. It turned out that in terms of interpretation of the results, it may not always be the most efficient to set this number at the theoretically best and recommended value. As a result of our analysis, several groups of airports with similar trend of post-event reactions are found. Therefore, this may bring better understanding of the intensity and the range of the impact of particular events on air transportation.

  17. Counting children at risk: exploring a method to estimate the number of children exposed to parental mental illness using adult health survey data.

    Science.gov (United States)

    Bassani, Diego Garcia; Padoin, Cintia Vontobel; Veldhuizen, Scott

    2008-11-01

    Children exposed to parental psychiatric disorders have an increased risk of several psychiatric disorders, impaired development, behavioural problems, injuries, physical illness and mortality. Even though this high-risk group has been shown to benefit from health promotion and preventive interventions, estimates of the size of the population at risk are not available. Estimating the number of exposed children using adult survey data will likely generate valuable information for health policy, planning, and advocacy. In this paper, the authors present a method to indirectly estimate the size of this population using secondary data. A Canadian adult health survey and the Census were combined to estimate the prevalence of exposure of children less than 12 years to parental and non-parental psychiatric disorders. A method to combine census and survey data is presented and tested under varying degrees of data availability. Results are compared to the actual number of children exposed to parental psychiatric disorders and discussed. The most accurate estimates were obtained when the most complete survey was combined with relatively detailed census information. Incomplete survey simulations produced substantial underestimates of the prevalence of exposure even when combined with detailed census information.

  18. Faint Submillimter Galaxy Counts at 450 micron

    CERN Document Server

    Chen, Chian-Chou; Barger, Amy J; Casey, Caitlin M; Lee, Nicholas; Sanders, David B; Wang, Wei-Hao; Williams, Jonathan P

    2012-01-01

    We present the results of SCUBA2 observations at 450 micron and 850 micron of the field lensed by the massive cluster A370. With a total survey area > 100 arcmin2 and 1 sigma sensitivities of 3.92 and 0.82 mJy/beam at 450 and 850 micron respectively, we find a secure sample of 20 sources at 450 micron and 26 sources at 850 micron with a signal-to-noise ratio > 4. Using the latest lensing model of A370 and Monte Carlo simulations, we derive the number counts at both wavelengths. The 450 micron number counts probe a factor of four deeper than the counts recently obtained from the Herschel Space Telescope at similar wavelengths, and we estimate that ~47-61% of the 450 micron extragalactic background light (EBL) resolved into individual sources with 450 micron fluxes greater than 4.5 mJy. The faint 450 micron sources in the 4 sigma sample have positional accuracies of 3 arcseconds, while brighter sources (signal-to-noise > 6 sigma) are good to 1.4 arcseconds. Using the deep radio map (1 sigma ~ 6 uJy) we find tha...

  19. The SCUBA-2 Cosmology Legacy Survey: The EGS deep field I - Deep number counts and the redshift distribution of the recovered Cosmic Infrared Background at 450 and 850 um

    CERN Document Server

    Zavala, J A; Geach, J E; Hughes, D H; Birkinshaw, M; Chapin, E; Chapman, S; Chen, Chian-Chou; Clements, D L; Dunlop, J S; Farrah, D; Ivison, R J; Jenness, T; Michałowski, M J; Robson, E I; Scott, Douglas; Simpson, J; Spaans, M; van der Werf, P

    2016-01-01

    We present deep observations at 450 um and 850 um in the Extended Groth Strip field taken with the SCUBA-2 camera mounted on the James Clerk Maxwell Telescope as part of the deep SCUBA-2 Cosmology Legacy Survey (S2CLS), achieving a central instrumental depth of $\\sigma_{450}=1.2$ mJy/beam and $\\sigma_{850}=0.2$ mJy/beam. We detect 57 sources at 450 um and 90 at 850 um with S/N > 3.5 over ~70 sq. arcmin. From these detections we derive the number counts at flux densities $S_{450}>4.0$ mJy and $S_{850}>0.9$ mJy, which represent the deepest number counts at these wavelengths derived using directly extracted sources from only blank-field observations with a single-dish telescope. Our measurements smoothly connect the gap between previous shallower blank-field single-dish observations and deep interferometric ALMA results. We estimate the contribution of our SCUBA-2 detected galaxies to the cosmic infrared background (CIB), as well as the contribution of 24 um-selected galaxies through a stacking technique, which ...

  20. Association studies of the copy-number variable ß-defensin cluster on 8p23.1 in adenocarcinoma and chronic pancreatitis

    Directory of Open Access Journals (Sweden)

    Taudien Stefan

    2012-11-01

    Full Text Available Abstract Background Human ß-defensins are a family of antimicrobial peptides located at the mucosal surface. Both sequence multi-site variations (MSV and copy-number variants (CNV of the defensin-encoding genes are associated with increased risk for various diseases, including cancer and inflammatory conditions such as psoriasis and acute pancreatitis. In a case–control study, we investigated the association between MSV in DEFB104 as well as defensin gene (DEF cluster copy number (CN, and pancreatic ductal adenocarcinoma (PDAC and chronic pancreatitis (CP. Results Two groups of PDAC (N=70 and CP (N=60 patients were compared to matched healthy control groups CARLA1 (N=232 and CARLA2 (N=160, respectively. Four DEFB104 MSV were haplotyped by PCR, cloning and sequencing. DEF cluster CN was determined by multiplex ligation-dependent probe amplification. Neither the PDAC nor the CP cohorts show significant differences in the DEFB104 haplotype distribution compared to the respective control groups CARLA1 and CARLA2, respectively. The diploid DEF cluster CN exhibit a significantly different distribution between PDAC and CARLA1 (Fisher’s exact test P=0.027, but not between CP and CARLA2 (P=0.867. Conclusion Different DEF cluster b CN distribution between PDAC patients and healthy controls indicate a potential protective effect of higher CNs against the disease.

  1. Copy number of pilus gene clusters in Haemophilus influenzae and variation in the hifE pilin gene.

    Science.gov (United States)

    Read, T D; Satola, S W; Opdyke, J A; Farley, M M

    1998-04-01

    Brazilian purpuric fever (BPF)-associated Haemophilus influenzae biogroup aegyptius strain F3031 contains two identical copies of a five gene cluster (hifA to hifE) encoding pili similar to well-characterized Hif fimbriae of H. influenzae type b. HifE, the putative pilus tip adhesin of F3031, shares only 40% amino acid sequence similarity with the same molecule from type b strains, whereas the other four proteins have 75 to 95% identity. To determine whether pilus cluster duplication and the hifE(F3031) allele were special features of BPF-associated bacteria, we analyzed a collection of H. influenzae strains by PCR with hifA- and hifE-specific oligonucleotides, by Southern hybridization with a hifC gene probe, and by nucleotide sequencing. The presence of two pilus clusters was limited to some H. influenzae biogroup aegyptius strains. The hifE(F3031) allele was limited to H. influenzae biogroup aegyptius. Two strains contained one copy of hifE(F3031) and one copy of a variant hifE allele. We determined the nucleotide sequences of four hifE genes from H. influenzae biogroup aegyptius and H. influenzae capsule serotypes a and c. The predicted proteins produced by these genes demonstrated only 35 to 70% identity to the three published HifE proteins from nontypeable H. influenzae, serotype b, and BPF strains. The C-terminal third of the molecules implicated in chaperone binding was the most highly conserved region. Three conserved domains in the otherwise highly variable N-terminal putative receptor-binding region of HifE were similar to conserved portions in the N terminus of Neisseria pilus adhesin PilC. We concluded that two pilus clusters and hifE(F3031) were not specific for BPF-causing H. influenzae, and we also identified portions of HifE possibly involved in binding mammalian cell receptors.

  2. Cluster-cluster clustering

    Science.gov (United States)

    Barnes, J.; Dekel, A.; Efstathiou, G.; Frenk, C. S.

    1985-01-01

    The cluster correlation function xi sub c(r) is compared with the particle correlation function, xi(r) in cosmological N-body simulations with a wide range of initial conditions. The experiments include scale-free initial conditions, pancake models with a coherence length in the initial density field, and hybrid models. Three N-body techniques and two cluster-finding algorithms are used. In scale-free models with white noise initial conditions, xi sub c and xi are essentially identical. In scale-free models with more power on large scales, it is found that the amplitude of xi sub c increases with cluster richness; in this case the clusters give a biased estimate of the particle correlations. In the pancake and hybrid models (with n = 0 or 1), xi sub c is steeper than xi, but the cluster correlation length exceeds that of the points by less than a factor of 2, independent of cluster richness. Thus the high amplitude of xi sub c found in studies of rich clusters of galaxies is inconsistent with white noise and pancake models and may indicate a primordial fluctuation spectrum with substantial power on large scales.

  3. Cluster-cluster clustering

    Energy Technology Data Exchange (ETDEWEB)

    Barnes, J.; Dekel, A.; Efstathiou, G.; Frenk, C.S.

    1985-08-01

    The cluster correlation function xi sub c(r) is compared with the particle correlation function, xi(r) in cosmological N-body simulations with a wide range of initial conditions. The experiments include scale-free initial conditions, pancake models with a coherence length in the initial density field, and hybrid models. Three N-body techniques and two cluster-finding algorithms are used. In scale-free models with white noise initial conditions, xi sub c and xi are essentially identical. In scale-free models with more power on large scales, it is found that the amplitude of xi sub c increases with cluster richness; in this case the clusters give a biased estimate of the particle correlations. In the pancake and hybrid models (with n = 0 or 1), xi sub c is steeper than xi, but the cluster correlation length exceeds that of the points by less than a factor of 2, independent of cluster richness. Thus the high amplitude of xi sub c found in studies of rich clusters of galaxies is inconsistent with white noise and pancake models and may indicate a primordial fluctuation spectrum with substantial power on large scales. 30 references.

  4. Natural vocalizations in the mammalian inferior colliculus are broadly encoded by a small number of independent multi-unit clusters

    Directory of Open Access Journals (Sweden)

    Dominika eLyzwa

    2016-02-01

    Full Text Available How complex natural sounds are represented by the main converging center of the auditory midbrain, the central inferior colliculus, is an open question. We applied neural discrimination to determine the variation of detailed encoding of individual vocalizations across the best frequency gradient of the central inferior colliculus. The analysis was based on collective responses from several neurons. These multi-unit spike trains were recorded from guinea pigs exposed to a spectrotemporally rich set of eleven species-specific vocalizations. Spike trains of disparate units from the same recording were combined in order to investigate whether groups of multi-unit clusters represent the whole set of vocalizations more reliably than only one unit, and whether temporal response correlations between them facilitate an unambiguous neural representation of the vocalizations. We found a spatial distribution of the capability to accurately encode groups of vocalizations across the best frequency gradient. Different vocalizations are optimally discriminated at different locations of the best frequency gradient. Furthermore, groups of a few multi-unit clusters yield improved discrimination over only one multi-unit cluster betweenall tested vocalizations. However, temporal response correlations between units do not yield better discrimination. Our study is based on a large set of units of simultaneously recorded responses from several guinea pigs and electrode insertion positions. Our findings suggest abroadly distributed code for behaviorally relevant vocalizations in the mammalian inferior colliculus.Responses from a few non-interacting units are sufficient to faithfully represent the whole set of studied vocalizations with diverse spectrotemporal properties.

  5. Galaxy populations in massive galaxy clusters to z = 1.1: colour distribution, concentration, halo occupation number and red sequence fraction

    Science.gov (United States)

    Hennig, C.; Mohr, J. J.; Zenteno, A.; Desai, S.; Dietrich, J. P.; Bocquet, S.; Strazzullo, V.; Saro, A.; Abbott, T. M. C.; Abdalla, F. B.; Bayliss, M.; Benoit-Lévy, A.; Bernstein, R. A.; Bertin, E.; Brooks, D.; Capasso, R.; Capozzi, D.; Carnero, A.; Carrasco Kind, M.; Carretero, J.; Chiu, I.; D'Andrea, C. B.; daCosta, L. N.; Diehl, H. T.; Doel, P.; Eifler, T. F.; Evrard, A. E.; Fausti-Neto, A.; Fosalba, P.; Frieman, J.; Gangkofner, C.; Gonzalez, A.; Gruen, D.; Gruendl, R. A.; Gupta, N.; Gutierrez, G.; Honscheid, K.; Hlavacek-Larrondo, J.; James, D. J.; Kuehn, K.; Kuropatkin, N.; Lahav, O.; March, M.; Marshall, J. L.; Martini, P.; McDonald, M.; Melchior, P.; Miller, C. J.; Miquel, R.; Neilsen, E.; Nord, B.; Ogando, R.; Plazas, A. A.; Reichardt, C.; Romer, A. K.; Rozo, E.; Rykoff, E. S.; Sanchez, E.; Santiago, B.; Schubnell, M.; Sevilla-Noarbe, I.; Smith, R. C.; Soares-Santos, M.; Sobreira, F.; Stalder, B.; Stanford, S. A.; Suchyta, E.; Swanson, M. E. C.; Tarle, G.; Thomas, D.; Vikram, V.; Walker, A. R.; Zhang, Y.

    2017-06-01

    We study the galaxy populations in 74 Sunyaev-Zeldovich effect selected clusters from the South Pole Telescope survey, which have been imaged in the science verification phase of the Dark Energy Survey. The sample extends up to z ˜ 1.1 with 4 × 1014 M⊙ ≤ M200 ≤ 3 × 1015M⊙. Using the band containing the 4000 Å break and its redward neighbour, we study the colour-magnitude distributions of cluster galaxies to ˜m* + 2, finding that: (1)The intrinsic rest frame g - r colour width of the red sequence (RS) population is ˜0.03 out to z ˜ 0.85 with a preference for an increase to ˜0.07 at z = 1, and (2) the prominence of the RS declines beyond z ˜ 0.6. The spatial distribution of cluster galaxies is well described by the NFW profile out to 4R200 with a concentration of cg = 3.59^{+0.20}_{-0.18}, 5.37^{+0.27}_{-0.24} and 1.38^{+0.21}_{-0.19} for the full, the RS and the blue non-RS populations, respectively, but with ˜40 per cent to 55 per cent cluster to cluster variation and no statistically significant redshift or mass trends. The number of galaxies within the virial region N200 exhibits a mass trend indicating that the number of galaxies per unit total mass is lower in the most massive clusters, and shows no significant redshift trend. The RS fraction within R200 is (68 ± 3) per cent at z = 0.46, varies from ˜55 per cent at z = 1 to ˜80 per cent at z = 0.1 and exhibits intrinsic variation among clusters of ˜14 per cent. We discuss a model that suggests that the observed redshift trend in RS fraction favours a transformation time-scale for infalling field galaxies to become RS galaxies of 2-3 Gyr.

  6. Clustering of Beijing genotype Mycobacterium tuberculosis isolates from the Mekong delta in Vietnam on the basis of variable number of tandem repeat versus restriction fragment length polymorphism typing

    Directory of Open Access Journals (Sweden)

    Huyen Mai NT

    2013-02-01

    Full Text Available Abstract Background In comparison to restriction fragment length polymorphism (RFLP typing, variable number of tandem repeat (VNTR typing is easier to perform, faster and yields results in a simple, numerical format. Therefore, this technique has gained recognition as the new international gold standard in typing of Mycobacterium tuberculosis. However, some reports indicated that VNTR typing may be less suitable for Beijing genotype isolates. We therefore compared the performance of internationally standardized RFLP and 24 loci VNTR typing to discriminate among 100 Beijing genotype isolates from the Southern Vietnam. Methods Hundred Beijing genotype strains defined by spoligotyping were randomly selected and typed by RFLP and VNTR typing. The discriminatory power of VNTR and RFLP typing was compared using the Bionumerics software. Results Among 95 Beijing strains available for analysis, 14 clusters were identified comprising 34 strains and 61 unique profiles in 24 loci VNTR typing ((Hunter Gaston Discrimination Index (HGDI = 0.994. 13 clusters containing 31 strains and 64 unique patterns in RFLP typing (HGDI = 0.994 were found. Nine RFLP clusters were subdivided by VNTR typing and 12 VNTR clusters were split by RFLP. Five isolates (5% revealing double alleles or no signal in two or more loci in VNTR typing could not be analyzed. Conclusions Overall, 24 loci VNTR typing and RFLP typing had similar high-level of discrimination among 95 Beijing strains from Southern Vietnam. However, loci VNTR 154, VNTR 2461 and VNTR 3171 had hardly added any value to the level of discrimination.

  7. Counting and Topological Order

    Institute of Scientific and Technical Information of China (English)

    陈阳军

    1997-01-01

    The counting method is a simple and efficient method for processing linear recursive datalog queries.Its time complexity is bounded by O(n,e)where n and e denote the numbers the numbers of nodes and edges,respectively,in the graph representing the input.relations.In this paper,the concepts of heritage appearance function and heritage selection function are introduced,and an evaluation algorithm based on the computation of such functions in topological order is developed .This new algorithm requires only linear time in the case of non-cyclic data.

  8. The SCUBA-2 Cosmology Legacy Survey: the EGS deep field - I. Deep number counts and the redshift distribution of the recovered cosmic infrared background at 450 and 850 μ m

    Science.gov (United States)

    Zavala, J. A.; Aretxaga, I.; Geach, J. E.; Hughes, D. H.; Birkinshaw, M.; Chapin, E.; Chapman, S.; Chen, Chian-Chou; Clements, D. L.; Dunlop, J. S.; Farrah, D.; Ivison, R. J.; Jenness, T.; Michałowski, M. J.; Robson, E. I.; Scott, Douglas; Simpson, J.; Spaans, M.; van der Werf, P.

    2017-01-01

    We present deep observations at 450 and 850 μm in the Extended Groth Strip field taken with the SCUBA-2 camera mounted on the James Clerk Maxwell Telescope as part of the deep SCUBA-2 Cosmology Legacy Survey (S2CLS), achieving a central instrumental depth of σ450 = 1.2 mJy beam-1 and σ850 = 0.2 mJy beam-1. We detect 57 sources at 450 μm and 90 at 850 μm with signal-to-noise ratio >3.5 over ˜70 arcmin2. From these detections, we derive the number counts at flux densities S450 > 4.0 mJy and S850 > 0.9 mJy, which represent the deepest number counts at these wavelengths derived using directly extracted sources from only blank-field observations with a single-dish telescope. Our measurements smoothly connect the gap between previous shallower blank-field single-dish observations and deep interferometric ALMA results. We estimate the contribution of our SCUBA-2 detected galaxies to the cosmic infrared background (CIB), as well as the contribution of 24 μm-selected galaxies through a stacking technique, which add a total of 0.26 ± 0.03 and 0.07 ± 0.01 MJy sr-1, at 450 and 850 μm, respectively. These surface brightnesses correspond to 60 ± 20 and 50 ± 20 per cent of the total CIB measurements, where the errors are dominated by those of the total CIB. Using the photometric redshifts of the 24 μm-selected sample and the redshift distributions of the submillimetre galaxies, we find that the redshift distribution of the recovered CIB is different at each wavelength, with a peak at z ˜ 1 for 450 μm and at z ˜ 2 for 850 μm, consistent with previous observations and theoretical models.

  9. 基于聚类NASVD的CE2-GRS月表放射性元素Th计数率分布%Distribution of the Thorium Counting Rate on the Lunar Surface from CE2-GRS Based on Cluster NASVD

    Institute of Scientific and Technical Information of China (English)

    李晓丽; 葛良全; 杨佳; 熊盛青

    2015-01-01

    月表Th元素分布特征对于分析月表岩石成因及化学特征等提供了重要依据。为了减小嫦娥二号伽玛谱(CE2-GRS)噪声对获取Th元素分布特征的影响,提出了一种基于噪声调整的奇异值分解(NASVD)去噪算法。通过伽玛谱预处理、去噪、本底扣除及净峰面积求解等步骤,获得月表放射性元素Th计数率全月分布图。通过与国内外其他方法所获得的Th元素计数率分布图对比有较高的一致性。与传统伽玛谱去噪算法比较,聚类NASVD算法能有效地去除统计涨落噪声影响,提取出嫦娥二号伽玛谱中的特征峰信息。%The distribution of thorium on the lunar surface provides the important evidence for lunar evolution history. It is difficult to obtain the distribution of thorium on the lunar surface from CE2-GRS because of noise in the spectrum. The method for smoothing the spectrum is proposed which is based on cluster NASVD. The counting rate map of thorium on the lunar surface is achieved from CE2-GRS. Counting rate map of thorium gamma-rays shows a surface thorium distribution that is in general agreement with other measurement from LP-GRS and SLENE GRS which have better accuracy. It is more effectively to reduce the noise and get the weak information of characteristic peak used the method of cluster NASVD than other traditional methods for smoothing gamma-ray spectrum.

  10. Counting carbon

    DEFF Research Database (Denmark)

    Damsø, Tue; Kjær, Tyge; Christensen, Thomas Budde

    2016-01-01

    The article contains an analysis of GHG accounting methodologies applied by local governments in Denmark. Eight Danish methodologies have been identified, a Danish best practice distinguished and assessed based on the criteria for good practice in GHG accounting: Relevance, comparability......, transparency, completeness, consistency and accuracy. In doing so a number of key concepts are defined and compared, and the relative relevance of the different criteria has been discussed. We observe a high degree of convergence among the Danish approaches in the application of data sources, quantification...... approaches and scope, identifying data availability as the key barrier for improving the specificity and dynamicity of local GHG accounts, and with it the accuracy and ability to monitor changes in emissions. In furthering an international best practice the Danish approach indicates that an adaptive approach...

  11. DC KIDS COUNT e-Databook Indicators

    Science.gov (United States)

    DC Action for Children, 2012

    2012-01-01

    This report presents indicators that are included in DC Action for Children's 2012 KIDS COUNT e-databook, their definitions and sources and the rationale for their selection. The indicators for DC KIDS COUNT represent a mix of traditional KIDS COUNT indicators of child well-being, such as the number of children living in poverty, and indicators of…

  12. Monte Carlo Simulation of Counting Experiments.

    Science.gov (United States)

    Ogden, Philip M.

    A computer program to perform a Monte Carlo simulation of counting experiments was written. The program was based on a mathematical derivation which started with counts in a time interval. The time interval was subdivided to form a binomial distribution with no two counts in the same subinterval. Then the number of subintervals was extended to…

  13. Effects of the number of markers per haplotype and clustering of haplotypes on the accuracy of QTL mapping and prediction of genomic breeding values

    Directory of Open Access Journals (Sweden)

    Schrooten Chris

    2009-01-01

    Full Text Available Abstract The aim of this paper was to compare the effect of haplotype definition on the precision of QTL-mapping and on the accuracy of predicted genomic breeding values. In a multiple QTL model using identity-by-descent (IBD probabilities between haplotypes, various haplotype definitions were tested i.e. including 2, 6, 12 or 20 marker alleles and clustering base haplotypes related with an IBD probability of > 0.55, 0.75 or 0.95. Simulated data contained 1100 animals with known genotypes and phenotypes and 1000 animals with known genotypes and unknown phenotypes. Genomes comprising 3 Morgan were simulated and contained 74 polymorphic QTL and 383 polymorphic SNP markers with an average r2 value of 0.14 between adjacent markers. The total number of haplotypes decreased up to 50% when the window size was increased from two to 20 markers and decreased by at least 50% when haplotypes related with an IBD probability of > 0.55 instead of > 0.95 were clustered. An intermediate window size led to more precise QTL mapping. Window size and clustering had a limited effect on the accuracy of predicted total breeding values, ranging from 0.79 to 0.81. Our conclusion is that different optimal window sizes should be used in QTL-mapping versus genome-wide breeding value prediction.

  14. Effects of the number of markers per haplotype and clustering of haplotypes on the accuracy of QTL mapping and prediction of genomic breeding values.

    Science.gov (United States)

    Calus, Mario P L; Meuwissen, Theo H E; Windig, Jack J; Knol, Egbert F; Schrooten, Chris; Vereijken, Addie L J; Veerkamp, Roel F

    2009-01-15

    The aim of this paper was to compare the effect of haplotype definition on the precision of QTL-mapping and on the accuracy of predicted genomic breeding values. In a multiple QTL model using identity-by-descent (IBD) probabilities between haplotypes, various haplotype definitions were tested i.e. including 2, 6, 12 or 20 marker alleles and clustering base haplotypes related with an IBD probability of > 0.55, 0.75 or 0.95. Simulated data contained 1100 animals with known genotypes and phenotypes and 1000 animals with known genotypes and unknown phenotypes. Genomes comprising 3 Morgan were simulated and contained 74 polymorphic QTL and 383 polymorphic SNP markers with an average r2 value of 0.14 between adjacent markers. The total number of haplotypes decreased up to 50% when the window size was increased from two to 20 markers and decreased by at least 50% when haplotypes related with an IBD probability of > 0.55 instead of > 0.95 were clustered. An intermediate window size led to more precise QTL mapping. Window size and clustering had a limited effect on the accuracy of predicted total breeding values, ranging from 0.79 to 0.81. Our conclusion is that different optimal window sizes should be used in QTL-mapping versus genome-wide breeding value prediction.

  15. How to count an introduction to combinatorics

    CERN Document Server

    Allenby, RBJT

    2010-01-01

    What's It All About? What Is Combinatorics? Classic Problems What You Need to Know Are You Sitting Comfortably? Permutations and Combinations The Combinatorial Approach Permutations CombinationsApplications to Probability Problems The Multinomial Theorem Permutations and Cycles Occupancy Problems Counting the Solutions of Equations New Problems from Old A ""Reduction"" Theorem for the Stirling Numbers The Inclusion-Exclusion Principle Double Counting Derangements A Formula for the Stirling NumbersStirling and Catalan Numbers Stirling Numbers Permutations and Stirling Numbers Catalan Numbers Pa

  16. The ALMA Spectroscopic Survey in the Hubble Ultra Deep Field: Continuum Number Counts, Resolved 1.2 mm Extragalactic Background, and Properties of the Faintest Dusty Star-forming Galaxies

    Science.gov (United States)

    Aravena, M.; Decarli, R.; Walter, F.; Da Cunha, E.; Bauer, F. E.; Carilli, C. L.; Daddi, E.; Elbaz, D.; Ivison, R. J.; Riechers, D. A.; Smail, I.; Swinbank, A. M.; Weiss, A.; Anguita, T.; Assef, R. J.; Bell, E.; Bertoldi, F.; Bacon, R.; Bouwens, R.; Cortes, P.; Cox, P.; Gónzalez-López, J.; Hodge, J.; Ibar, E.; Inami, H.; Infante, L.; Karim, A.; Le Le Fèvre, O.; Magnelli, B.; Ota, K.; Popping, G.; Sheth, K.; van der Werf, P.; Wagg, J.

    2016-12-01

    We present an analysis of a deep (1σ = 13 μJy) cosmological 1.2 mm continuum map based on ASPECS, the ALMA Spectroscopic Survey in the Hubble Ultra Deep Field. In the 1 arcmin2 covered by ASPECS we detect nine sources at \\gt 3.5σ significance at 1.2 mm. Our ALMA-selected sample has a median redshift of z=1.6+/- 0.4, with only one galaxy detected at z > 2 within the survey area. This value is significantly lower than that found in millimeter samples selected at a higher flux density cutoff and similar frequencies. Most galaxies have specific star formation rates (SFRs) similar to that of main-sequence galaxies at the same epoch, and we find median values of stellar mass and SFRs of 4.0× {10}10 {M}⊙ and ˜ 40 {M}⊙ yr-1, respectively. Using the dust emission as a tracer for the interstellar medium (ISM) mass, we derive depletion times that are typically longer than 300 Myr, and we find molecular gas fractions ranging from ˜0.1 to 1.0. As noted by previous studies, these values are lower than those using CO-based ISM estimates by a factor of ˜2. The 1 mm number counts (corrected for fidelity and completeness) are in agreement with previous studies that were typically restricted to brighter sources. With our individual detections only, we recover 55% ± 4% of the extragalactic background light (EBL) at 1.2 mm measured by the Planck satellite, and we recover 80% ± 7% of this EBL if we include the bright end of the number counts and additional detections from stacking. The stacked contribution is dominated by galaxies at z˜ 1{--}2, with stellar masses of (1-3) × 1010 M {}⊙ . For the first time, we are able to characterize the population of galaxies that dominate the EBL at 1.2 mm.

  17. The origins of counting algorithms.

    Science.gov (United States)

    Cantlon, Jessica F; Piantadosi, Steven T; Ferrigno, Stephen; Hughes, Kelly D; Barnard, Allison M

    2015-06-01

    Humans' ability to count by verbally labeling discrete quantities is unique in animal cognition. The evolutionary origins of counting algorithms are not understood. We report that nonhuman primates exhibit a cognitive ability that is algorithmically and logically similar to human counting. Monkeys were given the task of choosing between two food caches. First, they saw one cache baited with some number of food items, one item at a time. Then, a second cache was baited with food items, one at a time. At the point when the second set was approximately equal to the first set, the monkeys spontaneously moved to choose the second set even before that cache was completely baited. Using a novel Bayesian analysis, we show that the monkeys used an approximate counting algorithm for comparing quantities in sequence that is incremental, iterative, and condition controlled. This proto-counting algorithm is structurally similar to formal counting in humans and thus may have been an important evolutionary precursor to human counting. © The Author(s) 2015.

  18. Copy number variation of the beta defensin gene cluster on chromosome 8p influences the bacterial microbiota within the nasopharynx of otitis-prone children.

    Science.gov (United States)

    Jones, Eric A; Kananurak, Anchasa; Bevins, Charles L; Hollox, Edward J; Bakaletz, Lauren O

    2014-01-01

    As there is increasing evidence that aberrant defensin expression is related to susceptibility for infectious disease and inflammatory disorders, we sought to determine if copy number of the beta-defensin gene cluster located on chromosome 8p23.1 (DEFB107, 106, 105, 104, 103, DEFB4 and SPAG11), that shows copy number variation as a block, was associated with susceptibility to otitis media (OM). The gene DEFB103 within this complex encodes human beta defensin-3 (hBD-3), an antimicrobial peptide (AP) expressed by epithelial cells that line the mammalian airway, important for defense of mucosal surfaces and previously shown to have bactericidal activity in vitro against multiple human pathogens, including the three that predominate in OM. To this end, we conducted a retrospective case-control study of 113 OM prone children and 267 controls aged five to sixty months. We identified the copy number of the above defined beta-defensin gene cluster (DEFB-CN) in each study subject by paralogue ratio assays. The mean DEFB-CN was indistinguishable between subjects classified as OM prone based on a recent history of multiple episodes of OM and control subjects who had no history of OM (4.4 ± 0.96 versus 4.4 ± 1.08, respectively: Odds Ratio [OR]: 1.16 (95% CI: 0.61, 2.20). Despite a lack of direct association, we observed a statistically significant correlation between DEFB-CN and nasopharyngeal bacterial colonization patterns. Collectively, our findings suggested that susceptibility to OM might be mediated by genetic variation among individuals, wherein a DEFB-CN less than 4 exerts a marked influence on the microbiota of the nasopharynx, specifically with regard to colonization by the three predominant bacterial pathogens of OM.

  19. Copy number variation of the beta defensin gene cluster on chromosome 8p influences the bacterial microbiota within the nasopharynx of otitis-prone children.

    Directory of Open Access Journals (Sweden)

    Eric A Jones

    Full Text Available As there is increasing evidence that aberrant defensin expression is related to susceptibility for infectious disease and inflammatory disorders, we sought to determine if copy number of the beta-defensin gene cluster located on chromosome 8p23.1 (DEFB107, 106, 105, 104, 103, DEFB4 and SPAG11, that shows copy number variation as a block, was associated with susceptibility to otitis media (OM. The gene DEFB103 within this complex encodes human beta defensin-3 (hBD-3, an antimicrobial peptide (AP expressed by epithelial cells that line the mammalian airway, important for defense of mucosal surfaces and previously shown to have bactericidal activity in vitro against multiple human pathogens, including the three that predominate in OM. To this end, we conducted a retrospective case-control study of 113 OM prone children and 267 controls aged five to sixty months. We identified the copy number of the above defined beta-defensin gene cluster (DEFB-CN in each study subject by paralogue ratio assays. The mean DEFB-CN was indistinguishable between subjects classified as OM prone based on a recent history of multiple episodes of OM and control subjects who had no history of OM (4.4 ± 0.96 versus 4.4 ± 1.08, respectively: Odds Ratio [OR]: 1.16 (95% CI: 0.61, 2.20. Despite a lack of direct association, we observed a statistically significant correlation between DEFB-CN and nasopharyngeal bacterial colonization patterns. Collectively, our findings suggested that susceptibility to OM might be mediated by genetic variation among individuals, wherein a DEFB-CN less than 4 exerts a marked influence on the microbiota of the nasopharynx, specifically with regard to colonization by the three predominant bacterial pathogens of OM.

  20. Numbers and Numerals.

    Science.gov (United States)

    Smith, David Eugene; Ginsburg, Jekuthiel

    Counting, naming numbers, numerals, computation, and fractions are the topics covered in this pamphlet. Number lore and interesting number properties are noted; the derivation of some arithmetic terms is briefly discussed. (DT)

  1. Correction of the counting up number by dead time in detector systems for radiograph images; Correccion del numero de conteos por tiempo muerto en sistemas detectores para imagenes radiograficas

    Energy Technology Data Exchange (ETDEWEB)

    Cerdeira E, A. [Telital Spa, Trieste (Italy); Cicuttin, A. [Laboratory of Microprocessors, ICTP-INFN, Trieste (Italy); Cerdeira, A.; Estrada, M.; Luca, A. de [Depto. de Ingenieria Electrica, 07000 Mexico D.F. (Mexico)

    2002-07-01

    The effect of the dead time in a detection system by counting up of particles and the contribution of this error in the final image resolution is analysed. It is given a statistical criteria for the optimization of electronic parameters such as dead time and counting up memory which help in the implementation of these systems with the minimum necessary characteristics which satisfy the resolution requirements. (Author)

  2. A catalog of 203 galaxy clusters serendipitously detected in the ROSAT PSPC pointed observations

    DEFF Research Database (Denmark)

    Vikhlinin, A.; McNamara, B.R.; Forman, W.;

    1998-01-01

    We present a catalog of 203 clusters of galaxies serendipitously detected in 647 ROSAT PSPC high Galactic latitude pointings covering 158 deg(2). This is one of the largest X-ray-selected cluster samples, comparable in size only to the ROSAT All-Sky Survey sample of nearby clusters (Ebeling et al......), corresponding to very poor groups, to similar to 5 x 10(44) ergs s(-1), corresponding to rich clusters. The cluster redshifts range from z = 0.015 to z > 0.5. The catalog lists X-ray fluxes, core radii, and spectroscopic redshifts for 73 clusters and photometric redshifts for the remainder. Our detection method...... confirmed clusters. The number of false detections and their flux distribution are in perfect agreement with simulations. The log N-log S relation for clusters derived from our catalog shows excellent agreement with counts of bright clusters derived from the Einstein Extended Medium Sensitivity Survey...

  3. Verbal Counting in Bilingual Contexts

    Science.gov (United States)

    Donevska-Todorova, Ana

    2015-01-01

    Informal experiences in mathematics often include playful competitions among young children in counting numbers in as many as possible different languages. Can these enjoyable experiences result with excellence in the formal processes of education? This article discusses connections between mathematical achievements and natural languages within…

  4. The Big Pumpkin Count.

    Science.gov (United States)

    Coplestone-Loomis, Lenny

    1981-01-01

    Pumpkin seeds are counted after students convert pumpkins to jack-o-lanterns. Among the activities involved, pupils learn to count by 10s, make estimates, and to construct a visual representation of 1,000. (MP)

  5. Counting coalescent histories.

    Science.gov (United States)

    Rosenberg, Noah A

    2007-04-01

    Given a species tree and a gene tree, a valid coalescent history is a list of the branches of the species tree on which coalescences in the gene tree take place. I develop a recursion for the number of valid coalescent histories that exist for an arbitrary gene tree/species tree pair, when one gene lineage is studied per species. The result is obtained by defining a concept of m-extended coalescent histories, enumerating and counting these histories, and taking the special case of m = 1. As a sum over valid coalescent histories appears in a formula for the probability that a random gene tree evolving along the branches of a fixed species tree has a specified labeled topology, the enumeration of valid coalescent histories can considerably reduce the effort required for evaluating this formula.

  6. VersaCount: customizable manual tally software for cell counting

    Directory of Open Access Journals (Sweden)

    DeRisi Joseph L

    2010-01-01

    Full Text Available Abstract Background The manual counting of cells by microscopy is a commonly used technique across biological disciplines. Traditionally, hand tally counters have been used to track event counts. Although this method is adequate, there are a number of inefficiencies which arise when managing large numbers of samples or large sample sizes. Results We describe software that mimics a traditional multi-register tally counter. Full customizability allows operation on any computer with minimal hardware requirements. The efficiency of counting large numbers of samples and/or large sample sizes is improved through the use of a "multi-count" register that allows single keystrokes to correspond to multiple events. Automatically updated multi-parameter values are implemented as user-specified equations, reducing errors and time required for manual calculations. The user interface was optimized for use with a touch screen and numeric keypad, eliminating the need for a full keyboard and mouse. Conclusions Our software provides an inexpensive, flexible, and productivity-enhancing alternative to manual hand tally counters.

  7. Cosmology with Galaxy Clusters through the Sunyaev-Zel'dovich effect

    CERN Document Server

    Diego-Rodriguez, J M

    2002-01-01

    Future Sunyaev-Zel'dovich effect (SZE) surveys will detect thousands of clusters, many of them at high redshift. We show how the SZE number counts as a function of flux can be used as a useful way of constraining the cosmological model. The constraints can be dramatically improved if redshift information is provided for a small subsample of the observed clusters. In this work we present the constraints in Omega_m and Sigma_8 expected for a combined mm-optical survey. The mm survey (Planck) providing the cluster number counts as a function of flux and the optical survey (GTC) the redshift estimation of a small subsample of the cluster catalogue. We also show how it is possible to get an accurate estimate of the cluster flux using a non-parametric component separation algorithm and how using morphological redshifts it is possible to make a high-z preselection of the small subsample to be observed in the optical.

  8. The Origins of Counting Algorithms

    OpenAIRE

    Cantlon, Jessica F.; Piantadosi, Steven T.; Ferrigno, Stephen; Hughes, Kelly D.; Allison M Barnard

    2015-01-01

    Humans’ ability to ‘count’ by verbally labeling discrete quantities is unique in animal cognition. The evolutionary origins of counting algorithms are not understood. We report that non-human primates exhibit a cognitive ability that is algorithmically and logically similar to human counting. Monkeys were given the task of choosing between two food caches. Monkeys saw one cache baited with some number of food items, one item at a time. Then, a second cache was baited with food items, one at a...

  9. Tree modules and counting polynomials

    CERN Document Server

    Kinser, Ryan

    2011-01-01

    We give a formula for counting tree modules for the quiver S_g with g loops and one vertex in terms of tree modules on its universal cover. This formula, along with work of Helleloid and Rodriguez-Villegas, is used to show that the number of d-dimensional tree modules for S_g is polynomial in g with the same degree and leading coefficient as the counting polynomial A_{S_g}(d, q) for absolutely indecomposables over F_q, evaluated at q=1.

  10. Counting losses due to saturation effects of scintillation counters at high count rates

    CERN Document Server

    Hashimoto, K

    1999-01-01

    The counting statistics of a scintillation counter, with a preamplifier saturated by an overloading input, are investigated. First, the formulae for the variance and the mean number of counts, accumulated within a given gating time, are derived by considering counting-loss effects originating from the saturation and a finite resolving time of the electronic circuit. Numerical examples based on the formulae indicate that the saturation makes a positive contribution to the variance-to-mean ratio and that the contribution increases with count rate. Next the ratios are measured under high count rates when the preamplifier saturation can be observed. By fitting the present formula to the measured data, the counting-loss parameters can be evaluated. Corrections based on the parameters are made for various count rates measured in a nuclear reactor. As a result of the corrections, the linearity between count rate and reactor power can be restored.

  11. Constraining CMB-consistent primordial voids with cluster evolution

    CERN Document Server

    Mathis, H; Griffiths, L M; Kunz, M

    2004-01-01

    Using cosmological simulations, we make predictions for the distribution of clusters in a plausible non-gaussian model where primordial voids nucleated during inflation act together with scale-invariant adiabatic gaussian fluctuations as seeds for the formation of large-scale structure. This model agrees with most recent observations of the anisotropies of the cosmic microwave background (CMB) and can account for the excess of power measured on cluster scales by the Cosmic Background Imager (CBI), the large empty regions apparent in nearby galaxy redshift surveys and the number of giant arcs measured in deep cluster lensing surveys. We show that the z=0 cluster mass function differs from predictions for a standard LCDM cosmology with the same sigma_8. Moreover, as massive clusters also form much earlier in the "void" scenario, we show that integrated number counts of SZ sources and simple statistics of strong lensing can easily falsify this model.

  12. Noun Countability; Count Nouns and Non-count Nouns, What are the Syntactic Differences Between them?

    Directory of Open Access Journals (Sweden)

    Azhar A. Alkazwini

    2016-11-01

    Full Text Available Words that function as the subjects of verbs, objects of verbs or prepositions and which can have a plural form and possessive ending are known as nouns. They are described as referring to persons, places, things, states, or qualities and might also be used as an attributive modifier. In this paper, classes and subclasses of nouns shall be presented, then, noun countability branching into count and non-count nous shall be discussed. A number of present examples illustrating differences between count and non-count nouns and this includes determiner-head-co-occurrence restrictions of number, subject-verb agreement, in addition to some exceptions to this agreement rule shall be discussed. Also, the lexically inherent number in nouns and how inherently plural nouns are classified in terms of (+/- count are illustrated. This research will discuss partitive construction of count and non-count nouns, nouns as attributive modifier and, finally, conclude with the fact that there are syntactic difference between count and non-count in the English Language. Keywords: English Language, Nouns, Count, Non-count, Syntactic Differences, Proper Nouns

  13. Is It Counting, or Is It Adding?

    Science.gov (United States)

    Eisenhardt, Sara; Fisher, Molly H.; Thomas, Jonathan; Schack, Edna O.; Tassell, Janet; Yoder, Margaret

    2014-01-01

    The Common Core State Standards for Mathematics (CCSSI 2010) expect second grade students to "fluently add and subtract within 20 using mental strategies" (2.OA.B.2). Most children begin with number word sequences and counting approximations and then develop greater skill with counting. But do all teachers really understand how this…

  14. Is It Counting, or Is It Adding?

    Science.gov (United States)

    Eisenhardt, Sara; Fisher, Molly H.; Thomas, Jonathan; Schack, Edna O.; Tassell, Janet; Yoder, Margaret

    2014-01-01

    The Common Core State Standards for Mathematics (CCSSI 2010) expect second grade students to "fluently add and subtract within 20 using mental strategies" (2.OA.B.2). Most children begin with number word sequences and counting approximations and then develop greater skill with counting. But do all teachers really understand how this…

  15. Comprehensive assessment of sequence variation within the copy number variable defensin cluster on 8p23 by target enriched in-depth 454 sequencing

    Directory of Open Access Journals (Sweden)

    Zhang Xinmin

    2011-05-01

    Full Text Available Abstract Background In highly copy number variable (CNV regions such as the human defensin gene locus, comprehensive assessment of sequence variations is challenging. PCR approaches are practically restricted to tiny fractions, and next-generation sequencing (NGS approaches of whole individual genomes e.g. by the 1000 Genomes Project is confined by an affordable sequence depth. Combining target enrichment with NGS may represent a feasible approach. Results As a proof of principle, we enriched a ~850 kb section comprising the CNV defensin gene cluster DEFB, the invariable DEFA part and 11 control regions from two genomes by sequence capture and sequenced it by 454 technology. 6,651 differences to the human reference genome were found. Comparison to HapMap genotypes revealed sensitivities and specificities in the range of 94% to 99% for the identification of variations. Using error probabilities for rigorous filtering revealed 2,886 unique single nucleotide variations (SNVs including 358 putative novel ones. DEFB CN determinations by haplotype ratios were in agreement with alternative methods. Conclusion Although currently labor extensive and having high costs, target enriched NGS provides a powerful tool for the comprehensive assessment of SNVs in highly polymorphic CNV regions of individual genomes. Furthermore, it reveals considerable amounts of putative novel variations and simultaneously allows CN estimation.

  16. Arrangement and number of clustered regularly interspaced short palindromic repeat spacers are associated with erythromycin susceptibility in emm12, emm75 and emm92 of group A streptococcus.

    Science.gov (United States)

    Zheng, P-X; Chiang-Ni, C; Wang, S-Y; Tsai, P-J; Kuo, C-F; Chuang, W-J; Lin, Y-S; Liu, C-C; Wu, J-J

    2014-06-01

    Clustered regularly interspaced short palindromic repeats (CRISPR) are composed of numerous repeat-spacer units and are considered a prokaryotic defence system against foreign nucleic acids. Since antibiotic-resistant genes are frequently encoded in foreign nucleic acids, the aim of this study was to test whether erythromycin susceptibility in group A streptococcus (Streptococcus pyogenes) is associated with characteristics of CRISPR elements. Erythromycin susceptibility of 330 isolates collected between 1997 and 2003 was analysed. Among 29 emm types, emm12, emm75 and emm92 showed significant changes in erythromycin-resistance rates. By sequencing the spacers from two CRISPR loci, spacer contents in emm12, emm75 and emm92 strains were associated with erythromycin susceptibility. Strains with fewer spacers were more resistant to erythromycin. Moreover, in emm4 strains, which showed no significant change in their annual erythromycin-resistance rate, CRISPR type and number of spacers were not correlated with erythromycin susceptibility. These results highlight a novel association between CRISPR spacer content and erythromycin susceptibility in group A streptococcus.

  17. The DUB/USP17 deubiquitinating enzymes: A gene family within a tandemly repeated sequence, is also embedded within the copy number variable Beta-defensin cluster

    Directory of Open Access Journals (Sweden)

    Scott Christopher J

    2010-04-01

    Full Text Available Abstract Background The DUB/USP17 subfamily of deubiquitinating enzymes were originally identified as immediate early genes induced in response to cytokine stimulation in mice (DUB-1, DUB-1A, DUB-2, DUB-2A. Subsequently we have identified a number of human family members and shown that one of these (DUB-3 is also cytokine inducible. We originally showed that constitutive expression of DUB-3 can block cell proliferation and more recently we have demonstrated that this is due to its regulation of the ubiquitination and activity of the 'CAAX' box protease RCE1. Results Here we demonstrate that the human DUB/USP17 family members are found on both chromosome 4p16.1, within a block of tandem repeats, and on chromosome 8p23.1, embedded within the copy number variable beta-defensin cluster. In addition, we show that the multiple genes observed in humans and other distantly related mammals have arisen due to the independent expansion of an ancestral sequence within each species. However, it is also apparent when sequences from humans and the more closely related chimpanzee are compared, that duplication events have taken place prior to these species separating. Conclusions The observation that the DUB/USP17 genes, which can influence cell growth and survival, have evolved from an unstable ancestral sequence which has undergone multiple and varied duplications in the species examined marks this as a unique family. In addition, their presence within the beta-defensin repeat raises the question whether they may contribute to the influence of this repeat on immune related conditions.

  18. Submillimeter Imaging of RCS022434-0002.5: Intense Activity in a High-Redshift Cluster?

    CERN Document Server

    Webb, T M A; Ivison, R J; Hoekstra, H; Gladders, M D; Barrientos, L F; Hsieh, B C

    2005-01-01

    We present deep 850micron imaging of the z=0.773 strong lensing galaxy cluster RCSJ022434-0002.5 from the Red-Sequence Cluster Survey (RCS). These data are part of a larger submillimeter survey of RCS clusters, with SCUBA on the JCMT. We find five objects at 850micron, all of which are also detected at either 1.4-GHz, 450micron or both. The number density of objects in this field is in general agreement with the blank-field source counts; however, when combined with other cluster surveys a general tendency of cluster fields towards higher submm number densities is seen, which may be the result of unrecognized submillimeter luminous cluster galaxies. Primarily employing optical photometric redshifts we show that two of the five submillimeter galaxies in this field are consistent with being cluster members, while two are more likely background systems.

  19. Data Clustering

    Science.gov (United States)

    Wagstaff, Kiri L.

    2012-03-01

    clustering, in which some partial information about item assignments or other components of the resulting output are already known and must be accommodated by the solution. Some algorithms seek a partition of the data set into distinct clusters, while others build a hierarchy of nested clusters that can capture taxonomic relationships. Some produce a single optimal solution, while others construct a probabilistic model of cluster membership. More formally, clustering algorithms operate on a data set X composed of items represented by one or more features (dimensions). These could include physical location, such as right ascension and declination, as well as other properties such as brightness, color, temporal change, size, texture, and so on. Let D be the number of dimensions used to represent each item, xi ∈ RD. The clustering goal is to produce an organization P of the items in X that optimizes an objective function f : P -> R, which quantifies the quality of solution P. Often f is defined so as to maximize similarity within a cluster and minimize similarity between clusters. To that end, many algorithms make use of a measure d : X x X -> R of the distance between two items. A partitioning algorithm produces a set of clusters P = {c1, . . . , ck} such that the clusters are nonoverlapping (c_i intersected with c_j = empty set, i != j) subsets of the data set (Union_i c_i=X). Hierarchical algorithms produce a series of partitions P = {p1, . . . , pn }. For a complete hierarchy, the number of partitions n’= n, the number of items in the data set; the top partition is a single cluster containing all items, and the bottom partition contains n clusters, each containing a single item. For model-based clustering, each cluster c_j is represented by a model m_j , such as the cluster center or a Gaussian distribution. The wide array of available clustering algorithms may seem bewildering, and covering all of them is beyond the scope of this chapter. Choosing among them for a

  20. Multivariate ultrametric root counting

    CERN Document Server

    Avendano, Martin

    2011-01-01

    Let $K$ be a field, complete with respect to a discrete non-archimedian valuation and let $k$ be the residue field. Consider a system $F$ of $n$ polynomial equations in $K\\vars$. Our first result is a reformulation of the classical Hensel's Lemma in the language of tropical geometry: we show sufficient conditions (semiregularity at $w$) that guarantee that the first digit map $\\delta:(K^\\ast)^n\\to(k^\\ast)^n$ is a one to one correspondence between the solutions of $F$ in $(K^\\ast)^n$ with valuation $w$ and the solutions in $(k^\\ast)^n$ of the initial form system ${\\rm in}_w(F)$. Using this result, we provide an explicit formula for the number of solutions in $(K^\\ast)^n$ of a certain class of systems of polynomial equations (called regular), characterized by having finite tropical prevariety, by having initial forms consisting only of binomials, and by being semiregular at any point in the tropical prevariety. Finally, as a consequence of the root counting formula, we obtain the expected number of roots in $(K...

  1. Analyzing indirect effects in cluster randomized trials : The effect of estimation method, number of groups and group sizes on accuracy and power

    NARCIS (Netherlands)

    Hox, Joop J.; Moerbeek, Mirjam; Kluytmans, Anouck; van de Schoot, Rens

    2014-01-01

    Cluster randomized trials assess the effect of an intervention that is carried out at the group or cluster level. Ajzen's theory of planned behavior is often used to model the effect of the intervention as an indirect effect mediated in turn by attitude, norms and behavioral intention. Structural

  2. An Automatic Clustering Technique for Optimal Clusters

    CERN Document Server

    Pavan, K Karteeka; Rao, A V Dattatreya; 10.5121/ijcsea.2011.1412

    2011-01-01

    This paper proposes a simple, automatic and efficient clustering algorithm, namely, Automatic Merging for Optimal Clusters (AMOC) which aims to generate nearly optimal clusters for the given datasets automatically. The AMOC is an extension to standard k-means with a two phase iterative procedure combining certain validation techniques in order to find optimal clusters with automation of merging of clusters. Experiments on both synthetic and real data have proved that the proposed algorithm finds nearly optimal clustering structures in terms of number of clusters, compactness and separation.

  3. Health Physics counting room

    CERN Multimedia

    1970-01-01

    The Health Physics counting room, where the quantity of induced radioactivity in materials is determined. This information is used to evaluate possible radiation hazards from the material investigated.

  4. Cluster editing

    DEFF Research Database (Denmark)

    Böcker, S.; Baumbach, Jan

    2013-01-01

    . The problem has been the inspiration for numerous algorithms in bioinformatics, aiming at clustering entities such as genes, proteins, phenotypes, or patients. In this paper, we review exact and heuristic methods that have been proposed for the Cluster Editing problem, and also applications......The Cluster Editing problem asks to transform a graph into a disjoint union of cliques using a minimum number of edge modifications. Although the problem has been proven NP-complete several times, it has nevertheless attracted much research both from the theoretical and the applied side...

  5. The Voronoi Tessellation Cluster Finder in 2 1 Dimensions

    Energy Technology Data Exchange (ETDEWEB)

    Soares-Santos, Marcelle; /Fermilab /Sao Paulo U.; de Carvalho, Reinaldo R.; /Sao Jose, INPE; Annis, James; /Fermilab; Gal, Roy R.; /Hawaii U.; La Barbera, Francesco; /Capodimonte Observ.; Lopes, Paulo A.A.; /Valongo Observ.; Wechsler, Risa H.; Busha, Michael T.; Gerke, Brian F.; /SLAC /KIPAC, Menlo Park

    2011-06-23

    We present a detailed description of the Voronoi Tessellation (VT) cluster finder algorithm in 2+1 dimensions, which improves on past implementations of this technique. The need for cluster finder algorithms able to produce reliable cluster catalogs up to redshift 1 or beyond and down to 10{sup 13.5} solar masses is paramount especially in light of upcoming surveys aiming at cosmological constraints from galaxy cluster number counts. We build the VT in photometric redshift shells and use the two-point correlation function of the galaxies in the field to both determine the density threshold for detection of cluster candidates and to establish their significance. This allows us to detect clusters in a self-consistent way without any assumptions about their astrophysical properties. We apply the VT to mock catalogs which extend to redshift 1.4 reproducing the ?CDM cosmology and the clustering properties observed in the Sloan Digital Sky Survey data. An objective estimate of the cluster selection function in terms of the completeness and purity as a function of mass and redshift is as important as having a reliable cluster finder. We measure these quantities by matching the VT cluster catalog with the mock truth table. We show that the VT can produce a cluster catalog with completeness and purity >80% for the redshift range up to {approx}1 and mass range down to {approx}10{sup 13.5} solar masses.

  6. The Voronoi Tessellation Cluster Finder in 2 1 Dimensions

    Energy Technology Data Exchange (ETDEWEB)

    Soares-Santos, Marcelle; /Fermilab /Sao Paulo U.; de Carvalho, Reinaldo R.; /Sao Jose, INPE; Annis, James; /Fermilab; Gal, Roy R.; /Hawaii U.; La Barbera, Francesco; /Capodimonte Observ.; Lopes, Paulo A.A.; /Valongo Observ.; Wechsler, Risa H.; Busha, Michael T.; Gerke, Brian F.; /SLAC /KIPAC, Menlo Park

    2011-06-23

    We present a detailed description of the Voronoi Tessellation (VT) cluster finder algorithm in 2+1 dimensions, which improves on past implementations of this technique. The need for cluster finder algorithms able to produce reliable cluster catalogs up to redshift 1 or beyond and down to 10{sup 13.5} solar masses is paramount especially in light of upcoming surveys aiming at cosmological constraints from galaxy cluster number counts. We build the VT in photometric redshift shells and use the two-point correlation function of the galaxies in the field to both determine the density threshold for detection of cluster candidates and to establish their significance. This allows us to detect clusters in a self-consistent way without any assumptions about their astrophysical properties. We apply the VT to mock catalogs which extend to redshift 1.4 reproducing the ?CDM cosmology and the clustering properties observed in the Sloan Digital Sky Survey data. An objective estimate of the cluster selection function in terms of the completeness and purity as a function of mass and redshift is as important as having a reliable cluster finder. We measure these quantities by matching the VT cluster catalog with the mock truth table. We show that the VT can produce a cluster catalog with completeness and purity >80% for the redshift range up to {approx}1 and mass range down to {approx}10{sup 13.5} solar masses.

  7. Anarthria impairs subvocal counting.

    Science.gov (United States)

    Cubelli, R; Nichelli, P; Pentore, R

    1993-12-01

    We studied subvocal counting in two pure anarthric patients. Analysis showed that they performed definitively worse than normal subjects free to articulate subvocally and their scores were in the lower bounds of the performances of subjects suppressing articulation. These results suggest that subvocal counting is impaired after anarthria.

  8. EcoCount

    Directory of Open Access Journals (Sweden)

    Phillip P. Allen

    2014-05-01

    Full Text Available Techniques that analyze biological remains from sediment sequences for environmental reconstructions are well established and widely used. Yet, identifying, counting, and recording biological evidence such as pollen grains remain a highly skilled, demanding, and time-consuming task. Standard procedure requires the classification and recording of between 300 and 500 pollen grains from each representative sample. Recording the data from a pollen count requires significant effort and focused resources from the palynologist. However, when an adaptation to the recording procedure is utilized, efficiency and time economy improve. We describe EcoCount, which represents a development in environmental data recording procedure. EcoCount is a voice activated fully customizable digital count sheet that allows the investigator to continuously interact with a field of view during the data recording. Continuous viewing allows the palynologist the opportunity to remain engaged with the essential task, identification, for longer, making pollen counting more efficient and economical. EcoCount is a versatile software package that can be used to record a variety of environmental evidence and can be installed onto different computer platforms, making the adoption by users and laboratories simple and inexpensive. The user-friendly format of EcoCount allows any novice to be competent and functional in a very short time.

  9. Survey on Text Document Clustering

    OpenAIRE

    M.Thangamani; Dr.P.Thangaraj

    2010-01-01

    Document clustering is also referred as text clustering, and its concept is merely equal to data clustering. It is hardly difficult to find the selective information from an ‘N’number of series information, so that document clustering came into picture. Basically cluster means a group of similar data, document clustering means segregating the data into different groups of similar data. Clustering can be of mathematical, statistical or numerical domain. Clustering is a fundamental data analysi...

  10. Making environmental DNA count.

    Science.gov (United States)

    Kelly, Ryan P

    2016-01-01

    The arc of reception for a new technology or method--like the reception of new information itself--can pass through predictable stages, with audiences' responses evolving from 'I don't believe it', through 'well, maybe' to 'yes, everyone knows that' to, finally, 'old news'. The idea that one can sample a volume of water, sequence DNA out of it, and report what species are living nearby has experienced roughly this series of responses among biologists, beginning with the microbial biologists who developed genetic techniques to reveal the unseen microbiome. 'Macrobial' biologists and ecologists--those accustomed to dealing with species they can see and count--have been slower to adopt such molecular survey techniques, in part because of the uncertain relationship between the number of recovered DNA sequences and the abundance of whole organisms in the sampled environment. In this issue of Molecular Ecology Resources, Evans et al. (2015) quantify this relationship for a suite of nine vertebrate species consisting of eight fish and one amphibian. Having detected all of the species present with a molecular toolbox of six primer sets, they consistently find DNA abundances are associated with species' biomasses. The strength and slope of this association vary for each species and each primer set--further evidence that there is no universal parameter linking recovered DNA to species abundance--but Evans and colleagues take a significant step towards being able to answer the next question audiences tend to ask: 'Yes, but how many are there?'

  11. A contagem oral como pré-requisito para a aquisição do conceito de número com crianças pré-escolares Oral counting as a pre-requisite for the acquisition of the concept of number with pre-scholars

    Directory of Open Access Journals (Sweden)

    Giseli Monteiro

    2002-01-01

    Full Text Available A contagem oral como pré-requisito para aquisição do conceito de número foi ensinada através do procedimento de escolha de acordo com o modelo com crianças pré-escolares. Aos dois grupos foram ensinadas as relações de equivalência entre número e quantidade, porém a contagem oral foi ensinada apenas para o Grupo Experimental. No treino foram utilizados estímulos impressos (números, palavras e figuras e auditivos (ditado. Ambos os grupos foram, então, submetidos a diferentes condições de teste para verificar o efeito da contagem oral. Na generalização foi utilizado um jogo de dominó. O desempenho dos sujeitos que foram submetidos ao ensino da contagem oral foi superior ao dos sujeitos que não passaram por esse procedimento. É discutida a importância da contagem oral na aquisição do conceito de número, sendo apontada como facilitadora no estabelecimento de relações de equivalência de estímulos não diretamente ensinadas (generalização.The oral counting as a pre-requisite for the acquisition of the concept of number taught through procedure of matching to sample with pre-scholars. To both groups were taught the equivalence relations between number and quantity, whereas the oral counting was taught just to the Experimental Group (EG. In training were used printed stimuli (numbers, words and figures and words dictated by the research. After that, both groups' subjects were assessed to different conditions of testing to evaluate the effects the oral counting. Lastly, all the subjects (CG and EG were given the Generalization Test I and Generalization Test II (game of domino, made out of all the relations. The behavior of subjects submitted to the training of oral counting was superior in relation of the subject's behavior that no submitted to that procedure. The importance of oral counting in the acquisition of the concept of numbers related to the setting up of the relations number-quantity is discussed, being the oral

  12. Observations of different core water cluster ions Y-(H2O)n (Y = O2, HOx, NOx, COx) and magic number in atmospheric pressure negative corona discharge mass spectrometry.

    Science.gov (United States)

    Sekimoto, Kanako; Takayama, Mitsuo

    2011-01-01

    Reliable mass spectrometry data from large water clusters Y(-)(H(2)O)(n) with various negative core ions Y(-) such as O(2)(-), HO(-), HO(2)(-), NO(2)(-), NO(3)(-), NO(3)(-)(HNO(3))(2), CO(3)(-) and HCO(4)(-) have been obtained using atmospheric pressure negative corona discharge mass spectrometry. All the core Y(-) ions observed were ionic species that play a central role in tropospheric ion chemistry. These mass spectra exhibited discontinuities in ion peak intensity at certain size clusters Y(-)(H(2)O)(m) indicating specific thermochemical stability. Thus, Y(-)(H(2)O)(m) may correspond to the magic number or first hydrated shell in the cluster series Y(-)(H(2)O)(n). The high intensity discontinuity at HO(-)(H(2)O)(3) observed was the first mass spectrometric evidence for the specific stability of HO(-)(H(2)O)(3) as the first hydrated shell which Eigen postulated in 1964. The negative ion water clusters Y(-)(H(2)O)(n) observed in the mass spectra are most likely to be formed via core ion formation in the ambient discharge area (760 torr) and the growth of water clusters by adiabatic expansion in the vacuum region of the mass spectrometers (≈1 torr). The detailed mechanism of the formation of the different core water cluster ions Y(-)(H(2)O)(n) is described.

  13. Deep Source-Counting at 3 GHz

    Science.gov (United States)

    Vernstrom, Tessa; Wall, Jasper; Scott, Douglas

    2014-05-01

    We describe an analysis of 3-GHz confusion-limited data from the Karl J. Jansky Very Large Array (VLA). We show that with minimal model assumptions, P(D), Bayesian and Markov-Chain Mone-Carlo (MCMC) methods can define the source count to levels some 10 times fainter than the conventional confusion limit. Our verification process includes a full realistic simulation that considers known information on source angular extent and clustering. It appears that careful analysis of the statistical properties of an image is more effective than counting individual objects.

  14. The Complexity of Approximately Counting Stable Matchings

    CERN Document Server

    Chebolu, Prasad; Martin, Russell

    2010-01-01

    We investigate the complexity of approximately counting stable matchings in the $k$-attribute model, where the preference lists are determined by dot products of "preference vectors" with "attribute vectors", or by Euclidean distances between "preference points" and "attribute points". Irving and Leather proved that counting the number of stable matchings in the general case is $#P$-complete. Counting the number of stable matchings is reducible to counting the number of downsets in a (related) partial order and is interreducible, in an approximation-preserving sense, to a class of problems that includes counting the number of independent sets in a bipartite graph ($#BIS$). It is conjectured that no FPRAS exists for this class of problems. We show this approximation-preserving interreducibilty remains even in the restricted $k$-attribute setting when $k \\geq 3$ (dot products) or $k \\geq 2$ (Euclidean distances). Finally, we show it is easy to count the number of stable matchings in the 1-attribute dot-product ...

  15. Counting solutions for the N -queens and Latin-square problems by Monte Carlo simulations.

    Science.gov (United States)

    Zhang, Cheng; Ma, Jianpeng

    2009-01-01

    We apply Monte Carlo simulations to count the numbers of solutions of two well-known combinatorial problems: the N -queens problem and Latin-square problem. The original system is first converted to a general thermodynamic system, from which the number of solutions of the original system is obtained by using the method of computing the partition function. Collective moves are used to further accelerate sampling: swap moves are used in the N -queens problem and a cluster algorithm is developed for the Latin squares. The method can handle systems of 10;{4}degrees of freedom with more than 10;{10,000} solutions.

  16. 1996 : Track Count Protocol

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The goal of St. Vincent National Wildlife Refuge's Track Count Protocol is to provide an index to the population size of game animals inhabiting St. Vincent Island.

  17. Counting Belief Propagation

    CERN Document Server

    Kersting, Kristian; Natarajan, Sriraam

    2012-01-01

    A major benefit of graphical models is that most knowledge is captured in the model structure. Many models, however, produce inference problems with a lot of symmetries not reflected in the graphical structure and hence not exploitable by efficient inference techniques such as belief propagation (BP). In this paper, we present a new and simple BP algorithm, called counting BP, that exploits such additional symmetries. Starting from a given factor graph, counting BP first constructs a compressed factor graph of clusternodes and clusterfactors, corresponding to sets of nodes and factors that are indistinguishable given the evidence. Then it runs a modified BP algorithm on the compressed graph that is equivalent to running BP on the original factor graph. Our experiments show that counting BP is applicable to a variety of important AI tasks such as (dynamic) relational models and boolean model counting, and that significant efficiency gains are obtainable, often by orders of magnitude.

  18. Analog multivariate counting analyzers

    CERN Document Server

    Nikitin, A V; Armstrong, T P

    2003-01-01

    Characterizing rates of occurrence of various features of a signal is of great importance in numerous types of physical measurements. Such signal features can be defined as certain discrete coincidence events, e.g. crossings of a signal with a given threshold, or occurrence of extrema of a certain amplitude. We describe measuring rates of such events by means of analog multivariate counting analyzers. Given a continuous scalar or multicomponent (vector) input signal, an analog counting analyzer outputs a continuous signal with the instantaneous magnitude equal to the rate of occurrence of certain coincidence events. The analog nature of the proposed analyzers allows us to reformulate many problems of the traditional counting measurements, and cast them in a form which is readily addressed by methods of differential calculus rather than by algebraic or logical means of digital signal processing. Analog counting analyzers can be easily implemented in discrete or integrated electronic circuits, do not suffer fro...

  19. Housing Inventory Count

    Data.gov (United States)

    Department of Housing and Urban Development — This report displays the data communities reported to HUD about the nature of their dedicated homeless inventory, referred to as their Housing Inventory Count (HIC)....

  20. Allegheny County Traffic Counts

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — Traffic sensors at over 1,200 locations in Allegheny County collect vehicle counts for the Pennsylvania Department of Transportation. Data included in the Health...

  1. Liquid Scintillation Counting

    OpenAIRE

    Carlsson, Sten

    1993-01-01

    In liquid scintillation counting (LSC) we use the process of luminescense to detect ionising radiation emit$ed from a radionuclide. Luminescense is emission of visible light of nonthermal origin. 1t was early found that certain organic molecules have luminescent properties and such molecules are used in LSC. Today LSC is the mostwidespread method to detect pure beta-ernitters like tritium and carbon-14. 1t has unique properties in its efficient counting geometry, deteetability and the lack of...

  2. Counting RG flows

    OpenAIRE

    Gukov, Sergei

    2016-01-01

    Interpreting renormalization group flows as solitons interpolating between different fixed points, we ask various questions that are normally asked in soliton physics but not in renormalization theory. Can one count RG flows? Are there different "topological sectors" for RG flows? What is the moduli space of an RG flow, and how does it compare to familiar moduli spaces of (supersymmetric) dowain walls? Analyzing these questions in a wide variety of contexts --- from counting RG walls to AdS/C...

  3. Factorial PD-Clustering

    CERN Document Server

    Tortora, Cristina; Summa, Mireille Gettler

    2011-01-01

    Factorial clustering methods have been developed in recent years thanks to the improving of computational power. These methods perform a linear transformation of data and a clustering on transformed data optimizing a common criterion. Factorial PD-clustering is based on Probabilistic Distance clustering (PD-clustering). PD-clustering is an iterative, distribution free, probabilistic, clustering method. Factorial PD-clustering make a linear transformation of original variables into a reduced number of orthogonal ones using a common criterion with PD-Clustering. It is demonstrated that Tucker 3 decomposition allows to obtain this transformation. Factorial PD-clustering makes alternatively a Tucker 3 decomposition and a PD-clustering on transformed data until convergence. This method could significantly improve the algorithm performance and allows to work with large dataset, to improve the stability and the robustness of the method.

  4. Neutron counting with cameras

    Energy Technology Data Exchange (ETDEWEB)

    Van Esch, Patrick; Crisanti, Marta; Mutti, Paolo [Institut Laue Langevin, Grenoble (France)

    2015-07-01

    A research project is presented in which we aim at counting individual neutrons with CCD-like cameras. We explore theoretically a technique that allows us to use imaging detectors as counting detectors at lower counting rates, and transits smoothly to continuous imaging at higher counting rates. As such, the hope is to combine the good background rejection properties of standard neutron counting detectors with the absence of dead time of integrating neutron imaging cameras as well as their very good spatial resolution. Compared to Xray detection, the essence of thermal neutron detection is the nuclear conversion reaction. The released energies involved are of the order of a few MeV, while X-ray detection releases energies of the order of the photon energy, which is in the 10 KeV range. Thanks to advances in camera technology which have resulted in increased quantum efficiency, lower noise, as well as increased frame rate up to 100 fps for CMOS-type cameras, this more than 100-fold higher available detection energy implies that the individual neutron detection light signal can be significantly above the noise level, as such allowing for discrimination and individual counting, which is hard to achieve with X-rays. The time scale of CMOS-type cameras doesn't allow one to consider time-of-flight measurements, but kinetic experiments in the 10 ms range are possible. The theory is next confronted to the first experimental results. (authors)

  5. 21 CFR 1210.16 - Method of bacterial count.

    Science.gov (United States)

    2010-04-01

    ... FEDERAL IMPORT MILK ACT Inspection and Testing § 1210.16 Method of bacterial count. The bacterial count of milk and cream refers to the number of viable bacteria as determined by the standard plate method of... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Method of bacterial count. 1210.16 Section...

  6. Counts-in-Cylinders in the Sloan Digital Sky Survey with Comparisons to N-Body

    Energy Technology Data Exchange (ETDEWEB)

    Berrier, Heather D.; Barton, Elizabeth J.; /UC, Irvine; Berrier, Joel C.; /Arkansas U.; Bullock, James S.; /UC, Irvine; Zentner, Andrew R.; /Pittsburgh U.; Wechsler, Risa H. /KIPAC, Menlo Park /SLAC

    2010-12-16

    Environmental statistics provide a necessary means of comparing the properties of galaxies in different environments and a vital test of models of galaxy formation within the prevailing, hierarchical cosmological model. We explore counts-in-cylinders, a common statistic defined as the number of companions of a particular galaxy found within a given projected radius and redshift interval. Galaxy distributions with the same two-point correlation functions do not necessarily have the same companion count distributions. We use this statistic to examine the environments of galaxies in the Sloan Digital Sky Survey, Data Release 4. We also make preliminary comparisons to four models for the spatial distributions of galaxies, based on N-body simulations, and data from SDSS DR4 to study the utility of the counts-in-cylinders statistic. There is a very large scatter between the number of companions a galaxy has and the mass of its parent dark matter halo and the halo occupation, limiting the utility of this statistic for certain kinds of environmental studies. We also show that prevalent, empirical models of galaxy clustering that match observed two- and three-point clustering statistics well fail to reproduce some aspects of the observed distribution of counts-in-cylinders on 1, 3 and 6-h{sup -1}Mpc scales. All models that we explore underpredict the fraction of galaxies with few or no companions in 3 and 6-h{sup -1} Mpc cylinders. Roughly 7% of galaxies in the real universe are significantly more isolated within a 6 h{sup -1} Mpc cylinder than the galaxies in any of the models we use. Simple, phenomenological models that map galaxies to dark matter halos fail to reproduce high-order clustering statistics in low-density environments.

  7. Nice numbers

    CERN Document Server

    Barnes, John

    2016-01-01

    In this intriguing book, John Barnes takes us on a journey through aspects of numbers much as he took us on a geometrical journey in Gems of Geometry. Similarly originating from a series of lectures for adult students at Reading and Oxford University, this book touches a variety of amusing and fascinating topics regarding numbers and their uses both ancient and modern. The author intrigues and challenges his audience with both fundamental number topics such as prime numbers and cryptography, and themes of daily needs and pleasures such as counting one's assets, keeping track of time, and enjoying music. Puzzles and exercises at the end of each lecture offer additional inspiration, and numerous illustrations accompany the reader. Furthermore, a number of appendices provides in-depth insights into diverse topics such as Pascal’s triangle, the Rubik cube, Mersenne’s curious keyboards, and many others. A theme running through is the thought of what is our favourite number. Written in an engaging and witty sty...

  8. Approximate Counting of Graphical Realizations.

    Science.gov (United States)

    Erdős, Péter L; Kiss, Sándor Z; Miklós, István; Soukup, Lajos

    2015-01-01

    In 1999 Kannan, Tetali and Vempala proposed a MCMC method to uniformly sample all possible realizations of a given graphical degree sequence and conjectured its rapidly mixing nature. Recently their conjecture was proved affirmative for regular graphs (by Cooper, Dyer and Greenhill, 2007), for regular directed graphs (by Greenhill, 2011) and for half-regular bipartite graphs (by Miklós, Erdős and Soukup, 2013). Several heuristics on counting the number of possible realizations exist (via sampling processes), and while they work well in practice, so far no approximation guarantees exist for such an approach. This paper is the first to develop a method for counting realizations with provable approximation guarantee. In fact, we solve a slightly more general problem; besides the graphical degree sequence a small set of forbidden edges is also given. We show that for the general problem (which contains the Greenhill problem and the Miklós, Erdős and Soukup problem as special cases) the derived MCMC process is rapidly mixing. Further, we show that this new problem is self-reducible therefore it provides a fully polynomial randomized approximation scheme (a.k.a. FPRAS) for counting of all realizations.

  9. Approximate Counting of Graphical Realizations.

    Directory of Open Access Journals (Sweden)

    Péter L Erdős

    Full Text Available In 1999 Kannan, Tetali and Vempala proposed a MCMC method to uniformly sample all possible realizations of a given graphical degree sequence and conjectured its rapidly mixing nature. Recently their conjecture was proved affirmative for regular graphs (by Cooper, Dyer and Greenhill, 2007, for regular directed graphs (by Greenhill, 2011 and for half-regular bipartite graphs (by Miklós, Erdős and Soukup, 2013. Several heuristics on counting the number of possible realizations exist (via sampling processes, and while they work well in practice, so far no approximation guarantees exist for such an approach. This paper is the first to develop a method for counting realizations with provable approximation guarantee. In fact, we solve a slightly more general problem; besides the graphical degree sequence a small set of forbidden edges is also given. We show that for the general problem (which contains the Greenhill problem and the Miklós, Erdős and Soukup problem as special cases the derived MCMC process is rapidly mixing. Further, we show that this new problem is self-reducible therefore it provides a fully polynomial randomized approximation scheme (a.k.a. FPRAS for counting of all realizations.

  10. Photon counting digital holography

    Science.gov (United States)

    Demoli, Nazif; Skenderović, Hrvoje; Stipčević, Mario; Pavičić, Mladen

    2016-05-01

    Digital holography uses electronic sensors for hologram recording and numerical method for hologram reconstruction enabling thus the development of advanced holography applications. However, in some cases, the useful information is concealed in a very wide dynamic range of illumination intensities and successful recording requires an appropriate dynamic range of the sensor. An effective solution to this problem is the use of a photon-counting detector. Such detectors possess counting rates of the order of tens to hundreds of millions counts per second, but conditions of recording holograms have to be investigated in greater detail. Here, we summarize our main findings on this problem. First, conditions for optimum recording of digital holograms for detecting a signal significantly below detector's noise are analyzed in terms of the most important holographic measures. Second, for time-averaged digital holograms, optimum recordings were investigated for exposures shorter than the vibration cycle. In both cases, these conditions are studied by simulations and experiments.

  11. Galaxy Populations in Massive Galaxy Clusters to z=1.1: Color Distribution, Concentration, Halo Occupation Number and Red Sequence Fraction

    CERN Document Server

    Hennig, C; Zenteno, A; Desai, S; Dietrich, J P; Bocquet, S; Strazzullo, V; Saro, A; Abbott, T M C; Abdalla, F B; Bayliss, M; Benoit-Levy, A; Bernstein, R A; Bertin, E; Brooks, D; Capasso, R; Capozzi, D; Carnero, A; Kind, M Carrasco; Carretero, J; Chiu, I; D'Andrea, C B; daCosta, L N; Diehl, H T; Doel, P; Eifler, T F; Evrard, A E; Fausti-Neto, A; Fosalba, P; Frieman, J; Gangkofner, C; Gonzalez, A; Gruen, D; Gruendl, R A; Gupta, N; Gutierrez, G; Honscheid, K; Hlavacek-Larrondo, J; James, D J; Kuehn, K; Kuropatkin, N; Lahav, O; March, M; Marshall, J L; Martini, P; McDonald, M; Melchior, P; Miller, C J; Miquel, R; Neilsen, E; Nord, B; Ogando, R; Plazas, A A; Reichardt, C; Romer, A K; Rozo, E; Rykoff, E S; Sanchez, E; Santiago, B; Schubnell, M; Sevilla-Noarbe, I; Smith, R C; Soares-Santos, M; Sobreira, F; Stalder, B; Stanford, S A; Suchyta, E; Swanson, M E C; Tarle, G; Thomas, D; Vikram, V; Walker, A R; Zhang, Y

    2016-01-01

    We study the galaxy populations in 74 Sunyaev Zeldovich Effect (SZE) selected clusters from the South Pole Telescope (SPT) survey that have been imaged in the science verification phase of the Dark Energy Survey (DES). The sample extends up to $z\\sim 1.1$ with $4 \\times 10^{14} M_{\\odot}\\le M_{200}\\le 3\\times 10^{15} M_{\\odot}$. Using the band containing the 4000~\\AA\\ break and its redward neighbor, we study the color-magnitude distributions of cluster galaxies to $\\sim m_*+2$, finding: (1) the intrinsic rest frame $g-r$ color width of the red sequence (RS) population is $\\sim$0.03 out to $z\\sim0.85$ with a preference for an increase to $\\sim0.07$ at $z=1$ and (2) the prominence of the RS declines beyond $z\\sim0.6$. The spatial distribution of cluster galaxies is well described by the NFW profile out to $4R_{200}$ with a concentration of $c_{\\mathrm{g}} = 3.59^{+0.20}_{-0.18}$, $5.37^{+0.27}_{-0.24}$ and $1.38^{+0.21}_{-0.19}$ for the full, the RS and the blue non-RS populations, respectively, but with $\\sim4...

  12. Rainflow counting revisited

    Energy Technology Data Exchange (ETDEWEB)

    Soeker, H. [Deutsches Windenergie-Institut (Germany)

    1996-09-01

    As state of the art method the rainflow counting technique is presently applied everywhere in fatigue analysis. However, the author feels that the potential of the technique is not fully recognized in wind energy industries as it is used, most of the times, as a mere data reduction technique disregarding some of the inherent information of the rainflow counting results. The ideas described in the following aim at exploitation of this information and making it available for use in the design and verification process. (au)

  13. Examine Counting Procedure among Students with Mild Intellectual Disability: A Case of Penang Malaysia

    Science.gov (United States)

    Taibat, Adiat B.; Ahmad, Aznan Che; Ghazali, Munirah

    2013-01-01

    This study investigates counting procedure in number counting based on gender among students with mild intellectual disability. Quantitative approach was used for testing counting procedure in number counting among these students. The samples for the study comprise fifteen male and fifteen female students with intellectual disability. Descriptive…

  14. [Effect of mouse genotype on the hematopoietic stem cell count. II. The number of hematopietic stem cells in BALB/c and CC57BR strain mice differing by the level of endogenous colony formation].

    Science.gov (United States)

    Kozlov, V A

    1979-01-01

    The number of stem hematopoietic cells in the hematopoietic organs of mice of BALB/c and CC57BR strains and (CC57BRXBALB/c)F1 hybrids was studied by the method of exogenous colony-forming units. The assay of migration of stem cells from the bone marrow to the spleen was carried out. It was found that the spleen and the bone marrow of mice of the studied genotypes contain approximately the same relative number of hematopoietic stem cells. The number of stem cells which migrate from the bone marrow to the spleen is greater in the mice of BALB/c strain than in the CC57BR mice.

  15. What Counts as Evidence?

    Science.gov (United States)

    Dougherty Stahl, Katherine A.

    2014-01-01

    Each disciplinary community has its own criteria for determining what counts as evidence of knowledge in their academic field. The criteria influence the ways that a community's knowledge is created, communicated, and evaluated. Situating reading, writing, and language instruction within the content areas enables teachers to explicitly…

  16. Reticulocyte Count Test

    Science.gov (United States)

    ... may be ordered when: CBC results show a decreased RBC count and/or a decreased hemoglobin and hematocrit A healthcare practitioner wants to ... and hematocrit, to help determine the degree and rate of overproduction of RBCs ... during pregnancy . Newborns have a higher percentage of reticulocytes, but ...

  17. What Counts as Prostitution?

    Directory of Open Access Journals (Sweden)

    Stuart P. Green

    2016-08-01

    Full Text Available What counts, or should count, as prostitution? In the criminal law today, prostitution is understood to involve the provision of sexual services in exchange for money or other benefits. But what exactly is a ‘sexual service’? And what exactly is the nature of the required ‘exchange’? The key to answering these questions is to recognize that how we choose to define prostitution will inevitably depend on why we believe one or more aspects of prostitution are wrong or harmful, or should be criminalized or otherwise deterred, in the first place. These judgements, in turn, will often depend on an assessment of the contested empirical evidence on which they rest. This article describes a variety of real-world contexts in which the ‘what counts as prostitution’ question has arisen, surveys a range of leading rationales for deterring prostitution, and demonstrates how the answer to the definition question depends on the answer to the normative question. The article concludes with some preliminary thoughts on how analogous questions about what should count as sexual conduct arise in the context of consensual offences such as adultery and incest, as well as non-consensual offences such as sexual assault.

  18. Statistical connection of peak counts to power spectrum and moments in weak-lensing field

    Science.gov (United States)

    Shirasaki, Masato

    2017-02-01

    The number density of local maxima of weak-lensing field, referred to as weak-lensing peak counts, can be used as a cosmological probe. However, its relevant cosmological information is still unclear. We study the relationship between the peak counts and other statistics in weak-lensing field by using 1000 ray-tracing simulations. We construct a local transformation of lensing field K to a new Gaussian field y, named local-Gaussianized transformation. We calibrate the transformation with numerical simulations so that the one-point distribution and the power spectrum of K can be reproduced from a single Gaussian field y and monotonic relation between y and K. Therefore, the correct information of two-point clustering and any order of moments in weak-lensing field should be preserved under local-Gaussianized transformation. We then examine if local-Gaussianized transformation can predict weak-lensing peak counts in simulations. The local-Gaussianized transformation is insufficient to explain weak-lensing peak counts in the absence of shape noise. The prediction by local-Gaussianized transformation underestimates the simulated peak counts with a level of ˜20-30 per cent over a wide range of peak heights. Local-Gaussianized transformation can predict the weak-lensing peak counts with an ˜10 per cent accuracy in the presence of shape noise. Our analyses suggest that the cosmological information beyond power spectrum and its moments would be necessary to predict the weak-lensing peak counts with a percent-level accuracy, which is an expected statistical uncertainty in upcoming wide-field galaxy surveys.

  19. Evolution of the cluster X-ray luminosity function

    DEFF Research Database (Denmark)

    Mullis, C.R.; Vikhlinin, A.; Henry, J.P.

    2004-01-01

    We report measurements of the cluster X-ray luminosity function out to z = 0.8 based on the final sample of 201 galaxy systems from the 160 Square Degree ROSAT Cluster Survey. There is little evidence for any measurable change in cluster abundance out to z similar to 0.6 at luminosities of less...... than a few times 10(44) h(50)(-2) ergs s(-1) (0.5 - 2.0 keV). However, for 0.6 cluster deficit using integrated number counts...... and a maximum likelihood analysis of the observed luminosity-redshift distribution fit with a model luminosity function. The negative evolution signal is more than 3 sigma regardless of the adopted local luminosity function or cosmological framework. Our results and those from several other surveys...

  20. Counting statistics for genetic switches based on effective interaction approximation

    Science.gov (United States)

    Ohkubo, Jun

    2012-09-01

    Applicability of counting statistics for a system with an infinite number of states is investigated. The counting statistics has been studied a lot for a system with a finite number of states. While it is possible to use the scheme in order to count specific transitions in a system with an infinite number of states in principle, we have non-closed equations in general. A simple genetic switch can be described by a master equation with an infinite number of states, and we use the counting statistics in order to count the number of transitions from inactive to active states in the gene. To avoid having the non-closed equations, an effective interaction approximation is employed. As a result, it is shown that the switching problem can be treated as a simple two-state model approximately, which immediately indicates that the switching obeys non-Poisson statistics.

  1. Counting statistics for genetic switches based on effective interaction approximation

    CERN Document Server

    Ohkubo, Jun

    2012-01-01

    Applicability of counting statistics for a system with an infinite number of states is investigated. The counting statistics has been studied a lot for a system with a finite number of states. While it is possible to use the scheme in order to count specific transitions in a system with an infinite number of states in principle, we have non-closed equations in general. A simple genetic switch can be described by a master equation with an infinite number of states, and we use the counting statistics in order to count the number of transitions from inactive to active states in the gene. To avoid to have the non-closed equations, an effective interaction approximation is employed. As a result, it is shown that the switching problem can be treated as a simple two-state model approximately, which immediately indicates that the switching obeys non-Poisson statistics.

  2. Improvement in the energy resolving capabilities of photon counting detectors

    Science.gov (United States)

    Kang, D.; Lim, K. T.; Park, K.; Cho, G.

    2016-12-01

    Patterned pixel array was proposed to increase the number of energy bins in a single pixel of photon counting detectors without adding more comparators and counters. The pixels were grouped into four different types and each pixel has a common threshold and a specific threshold assigned to each pixel type. The common threshold in every pixel records the total number of incident photons regardless of its pixel type and the specific thresholds classify incident photon energies. The patterned pixel array was evaluated with the pinhole gamma camera system based on the XRI-UNO detector flip-chip bonded with a 1mm thick CdTe sensor. The experimental data was acquired with time-over-threshold mode to avoid the charge sharing problem. The shared total charges created by one photon can be found by summing all pixels within the cluster. To correct the different response to the same energy of photon, the energy calibration of the time-over-threshold value was perfomed independently depending on the cluster size. The time-over-threshold values were separated into two energy bins since we assumed that each pixel has two thresholds. Although each pixel has only two thresholds, five images from different energy windows were obtained by sharing the spectal information from four adjacent pixels. Thus, degradation of the spatial resolution in the image occured in each energy window. The image of the entire energy, however, was not degraded since all four different types of pixels have a common threshold just above the noise level. In addition, the number of steps for the threshold scan method can be drastically reduced with the increased number of effective thresholds in a single pixel.

  3. High Count Rate Electron Probe Microanalysis

    Science.gov (United States)

    Geller, Joseph D.; Herrington, Charles

    2002-01-01

    Reducing the measurement uncertainty of quantitative analyses made using electron probe microanalyzers (EPMA) requires a careful study of the individual uncertainties from each definable step of the measurement. Those steps include measuring the incident electron beam current and voltage, knowing the angle between the electron beam and the sample (takeoff angle), collecting the emitted x rays from the sample, comparing the emitted x-ray flux to known standards (to determine the k-ratio) and transformation of the k-ratio to concentration using algorithms which includes, as a minimum, the atomic number, absorption, and fluorescence corrections. This paper discusses the collection and counting of the emitted x rays, which are diffracted into the gas flow or sealed proportional x-ray detectors. The representation of the uncertainty in the number of collected x rays collected reduces as the number of counts increase. The uncertainty of the collected signal is fully described by Poisson statistics. Increasing the number of x rays collected involves either counting longer or at a higher counting rate. Counting longer means the analysis time increases and may become excessive to get to the desired uncertainty. Instrument drift also becomes an issue. Counting at higher rates has its limitations, which are a function of the detector physics and the detecting electronics. Since the beginning of EPMA analysis, analog electronics have been used to amplify and discriminate the x-ray induced ionizations within the proportional counter. This paper will discuss the use of digital electronics for this purpose. These electronics are similar to that used for energy dispersive analysis of x rays with either Si(Li) or Ge(Li) detectors except that the shaping time constants are much smaller. PMID:27446749

  4. The right to count does not always count

    DEFF Research Database (Denmark)

    Sodemann, Morten

    2013-01-01

    The best prescription against illness is learning to read and to count. People who are unable to count have a harder time learning to read. People who have difficulty counting make poorer decisions, are less able to combine information and are less likely to have a strategy for life...

  5. Relevant Subspace Clustering

    DEFF Research Database (Denmark)

    Müller, Emmanuel; Assent, Ira; Günnemann, Stephan;

    2009-01-01

    Subspace clustering aims at detecting clusters in any subspace projection of a high dimensional space. As the number of possible subspace projections is exponential in the number of dimensions, the result is often tremendously large. Recent approaches fail to reduce results to relevant subspace c...

  6. Enhanced clustering tendency of Cu-impurities with a number of oxygen vacancies in heavy carbon-loaded TiO2 - the bulk and surface morphologies

    Science.gov (United States)

    Zatsepin, D. A.; Boukhvalov, D. W.; Kurmaev, E. Z.; Zatsepin, A. F.; Kim, S. S.; Gavrilov, N. V.; Zhidkov, I. S.

    2017-09-01

    The over threshold carbon-loadings (∼50 at.%) of initial TiO2-hosts and posterior Cu-sensitization (∼7 at.%) was made using pulsed ion-implantation technique in sequential mode with 1 h vacuum-idle cycle between sequential stages of embedding. The final Cx-TiO2:Cu samples were qualified using XPS wide-scan elemental analysis, core-levels and valence band mappings. The results obtained were discussed on the theoretic background employing DFT-calculations. The combined XPS-and-DFT analysis allows to establish and prove the final formula of the synthesized samples as Cx-TiO2:[Cu+][Cu2+] for the bulk and Cx-TiO2:[Cu+][Cu0] for thin-films. It was demonstrated the in the mode of heavy carbon-loadings the remaining majority of neutral C-C bonds (sp3-type) is dominating and only a lack of embedded carbon is fabricating the O-Cdbnd O clusters. No valence base-band width altering was established after sequential carbon-copper modification of the atomic structure of initial TiO2-hosts except the dominating majority of Cu 3s states after Cu-sensitization. The crucial role of neutral carbon low-dimensional impurities as the precursors for the new phases growth was shown for Cu-sensitized Cx-TiO2 intermediate-state hosts.

  7. Pedestrian Counting with Occlusion Handling Using Stereo Thermal Cameras

    DEFF Research Database (Denmark)

    Kristoffersen, Miklas Strøm; Dueholm, Jacob Velling; Gade, Rikke

    2016-01-01

    and the complexity of scenes with many people occluding one another. To address these challenges, this paper introduces the use of a stereo thermal camera setup for pedestrian counting. We investigate the reconstruction of 3D points in a pedestrian street with two thermal cameras and propose an algorithm...... for pedestrian counting based on clustering and tracking of the 3D point clouds. The method is tested on two five-minute video sequences captured at a public event with a moderate density of pedestrians and heavy occlusions. The counting performance is compared to the manually annotated ground truth and shows...

  8. Clustering of Beijing genotype Mycobacterium tuberculosis isolates from the Mekong delta in Vietnam on the basis of variable number of tandem repeat versus restriction fragment length polymorphism typing.

    NARCIS (Netherlands)

    Huyen, M.N.; Kremer, K.; Lan, N.T.; Buu, T.N.; Cobelens, F.G.; Tiemersma, E.W.; Haas, P. de; Soolingen, D. van

    2013-01-01

    BACKGROUND: In comparison to restriction fragment length polymorphism (RFLP) typing, variable number of tandem repeat (VNTR) typing is easier to perform, faster and yields results in a simple, numerical format. Therefore, this technique has gained recognition as the new international gold standard i

  9. Stalking the count. Dracula, Fandom and Tourism

    NARCIS (Netherlands)

    S.L. Reijnders (Stijn)

    2011-01-01

    textabstractLarge numbers of tourists travel to Transylvania every year, looking for traces of Count Dracula. This article investigates why people feel the need to connect fictional stories, such as Dracula, with identifiable physical locations, and why they subsequently want to visit these

  10. Maximum-likelihood model averaging to profile clustering of site types across discrete linear sequences.

    Directory of Open Access Journals (Sweden)

    Zhang Zhang

    2009-06-01

    Full Text Available A major analytical challenge in computational biology is the detection and description of clusters of specified site types, such as polymorphic or substituted sites within DNA or protein sequences. Progress has been stymied by a lack of suitable methods to detect clusters and to estimate the extent of clustering in discrete linear sequences, particularly when there is no a priori specification of cluster size or cluster count. Here we derive and demonstrate a maximum likelihood method of hierarchical clustering. Our method incorporates a tripartite divide-and-conquer strategy that models sequence heterogeneity, delineates clusters, and yields a profile of the level of clustering associated with each site. The clustering model may be evaluated via model selection using the Akaike Information Criterion, the corrected Akaike Information Criterion, and the Bayesian Information Criterion. Furthermore, model averaging using weighted model likelihoods may be applied to incorporate model uncertainty into the profile of heterogeneity across sites. We evaluated our method by examining its performance on a number of simulated datasets as well as on empirical polymorphism data from diverse natural alleles of the Drosophila alcohol dehydrogenase gene. Our method yielded greater power for the detection of clustered sites across a breadth of parameter ranges, and achieved better accuracy and precision of estimation of clusters, than did the existing empirical cumulative distribution function statistics.

  11. Maximum-likelihood model averaging to profile clustering of site types across discrete linear sequences.

    Directory of Open Access Journals (Sweden)

    Zhang Zhang

    2009-06-01

    Full Text Available A major analytical challenge in computational biology is the detection and description of clusters of specified site types, such as polymorphic or substituted sites within DNA or protein sequences. Progress has been stymied by a lack of suitable methods to detect clusters and to estimate the extent of clustering in discrete linear sequences, particularly when there is no a priori specification of cluster size or cluster count. Here we derive and demonstrate a maximum likelihood method of hierarchical clustering. Our method incorporates a tripartite divide-and-conquer strategy that models sequence heterogeneity, delineates clusters, and yields a profile of the level of clustering associated with each site. The clustering model may be evaluated via model selection using the Akaike Information Criterion, the corrected Akaike Information Criterion, and the Bayesian Information Criterion. Furthermore, model averaging using weighted model likelihoods may be applied to incorporate model uncertainty into the profile of heterogeneity across sites. We evaluated our method by examining its performance on a number of simulated datasets as well as on empirical polymorphism data from diverse natural alleles of the Drosophila alcohol dehydrogenase gene. Our method yielded greater power for the detection of clustered sites across a breadth of parameter ranges, and achieved better accuracy and precision of estimation of clusters, than did the existing empirical cumulative distribution function statistics.

  12. CalCOFI Egg Counts

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish egg counts and standardized counts for eggs captured in CalCOFI icthyoplankton nets (primarily vertical [Calvet or Pairovet], oblique [bongo or ring nets], and...

  13. High Red Blood Cell Count

    Science.gov (United States)

    Symptoms High red blood cell count By Mayo Clinic Staff A high red blood cell count is an increase in oxygen-carrying cells in your bloodstream. Red blood cells transport oxygen from your lungs to tissues throughout ...

  14. Count Number Product Quality Process Management and Test System Based on C++ Development and Application%基于C++开发的算号器产品品质流程管理监测系统与应用

    Institute of Scientific and Technical Information of China (English)

    金志虎; 范淑一; 金毅; 甘玉玺; 庞建荣; 王明贵; 王贵

    2015-01-01

    and the number of statistics, meanwhile the operating environment of this system requirements is not high and can run normally in the Windows XP running normal computer and IPv4/V6 local area network. Especially a large number of poka yoke design and graphical interface made this system has high usability, the production line workers can operate skillfully and use freely after simple training, it improved the production automation degree. The failure can locate the cause of the error and location quickly and accurately, therefore improved the product quality monitoring of speed, easy to improve the production process and technology. If necessary it can eliminate the potential risks through summing up and analysis of production test data. The first time, products pass rate up to 96% from 84% in the past, the final qualified products pass rate increase from 90% to 98%.

  15. Generalized Entropy Concentration for Counts

    CERN Document Server

    Oikonomou, Kostas N

    2016-01-01

    We consider the phenomenon of entropy concentration under linear constraints in a discrete setting, using the "balls and bins" paradigm, but without the assumption that the number of balls allocated to the bins is known. Therefore instead of \\ frequency vectors and ordinary entropy, we have count vectors with unknown sum, and a certain generalized entropy. We show that if the constraints bound the allowable sums, this suffices for concentration to occur even in this setting. The concentration can be either in terms of deviation from the maximum generalized entropy value, or in terms of the norm of the difference from the maximum generalized entropy vector. Without any asymptotic considerations, we quantify the concentration in terms of various parameters, notably a tolerance on the constraints which ensures that they are always satisfied by an integral vector. Generalized entropy maximization is not only compatible with ordinary MaxEnt, but can also be considered an extension of it, as it allows us to address...

  16. A THUMBNAIL HISTORY OF HETEROTROPHIC PLATE COUNT (HPC) METHODOLOGY IN THE UNITED STATES

    Science.gov (United States)

    Over the past 100 years, the method of determining the number of bacteria in water, foods or other materials has been termed variously as: bacterial plate count, total plate count, total viable plate count, aerobic plate count, standard plate cound and more recently, heterotrophi...

  17. Positive motivic measures are counting measures

    CERN Document Server

    Ellenberg, Jordan S

    2009-01-01

    Let K be a field. A positive motivic measure on the Grothendieck ring K_0(Var_K) is a homomorphism from K_0(Var_K) to the real numbers assigning a nonnegative value to every variety. In this note we show that the only positive motivic measures are the counting measures: measures on K_0(Var_{F_q}) which send a variety to its number of rational points over some fixed finite extension of F_q.

  18. Optimal allocation of point-count sampling effort

    Science.gov (United States)

    Barker, R.J.; Sauer, J.R.; Link, W.A.

    1993-01-01

    Both unlimited and fixedradius point counts only provide indices to population size. Because longer count durations lead to counting a higher proportion of individuals at the point, proper design of these surveys must incorporate both count duration and sampling characteristics of population size. Using information about the relationship between proportion of individuals detected at a point and count duration, we present a method of optimizing a pointcount survey given a fixed total time for surveying and travelling between count points. The optimization can be based on several quantities that measure precision, accuracy, or power of tests based on counts, including (1) meansquare error of estimated population change; (2) mean-square error of average count; (3) maximum expected total count; or (4) power of a test for differences in average counts. Optimal solutions depend on a function that relates count duration at a point to the proportion of animals detected. We model this function using exponential and Weibull distributions, and use numerical techniques to conduct the optimization. We provide an example of the procedure in which the function is estimated from data of cumulative number of individual birds seen for different count durations for three species of Hawaiian forest birds. In the example, optimal count duration at a point can differ greatly depending on the quantities that are optimized. Optimization of the mean-square error or of tests based on average counts generally requires longer count durations than does estimation of population change. A clear formulation of the goals of the study is a critical step in the optimization process.

  19. Counting Statistics and Ion Interval Density in AMS

    Energy Technology Data Exchange (ETDEWEB)

    Vogel, J S; Ognibene, T; Palmblad, M; Reimer, P

    2004-08-03

    Confidence in the precisions of AMS and decay measurements must be comparable for the application of the {sup 14}C calibration to age determinations using both technologies. We confirmed the random nature of the temporal distribution of {sup 14}C ions in an AMS spectrometer for a number of sample counting rates and properties of the sputtering process. The temporal distribution of ion counts was also measured to confirm the applicability of traditional counting statistics.

  20. Simulating HST observations of strong lensing clusters

    Science.gov (United States)

    Meneghetti, Massimo

    2014-10-01

    The Frontier Fields {FF} are using galaxy cluster gravitational lensing to boost the powers of Hubble and Spitzer to reveal the faintest galaxies yet observed. Accurate gravitational lensing models with uncertainty estimates are required to study some of the physical parameters of the lensed galaxies. Simulated HST observations of lensing clusters with known mass distributions are ideal to determine the accuracies of these modeling methods. Our team has begun performing these tests, demonstrating that integrated quantities such as lensed number counts are accurately recovered, enabling luminosity functions to be constrained. We have also begun to quantify magnification uncertainties for individual galaxies, but additional tests are needed. Here we propose to create a set of simulated osbervations of clusters selected to be analogs of the CLASH and FF clusters. They will include lensing effects and they will be delivered to the Mikulski Archive for Space Telescopes as a legacy product for others to analyze. They will be usable to extend our tests for robustly determine the accuracies in model magnification and mass measurements. Mass uncertainties will be a key ingredient in efforts to use galaxy clusters to constrain cosmology and theories of structure formation. Results from this program will also be useful to improve lens modeling methods toward more optimal use of the large numbers of lensing constraints available in deep FF imaging. This program will help astronomers realize the full potential of the large investments of Hubble, Spitzer, Chandra, and ground-based observing time in the FF, CLASH, and other past and future cluster lensing observations.

  1. Stellar Mass Segregation in the Aged Galactic Open Star Cluster Berkeley 17

    CERN Document Server

    Bhattacharya, Souradeep; Vaidya, Kaushar; Chen, Wen-Ping

    2016-01-01

    We present the analysis of the morphology of Berkeley\\,17, the oldest known open cluster ($\\sim10$ Gyr), using a probabilistic star counting of Pan-STARRS point sources, and confirm its core-tail shape, plus an antitail, previously detected with 2MASS data. The stellar population, as diagnosed by the color-magnitude diagram and theoretical isochrones, shows more massive than lower-mass members in the cluster core, whereas there is a paucity of massive members in both tails. This manifests mass segregation in this aged star cluster with the low-mass members being stripped away from the system. It has been claimed that Berkeley 17 is associated with an excessive number of blue stragglers. Our analysis in comparison of the cluster with nearby reference fields indicates that about half of the blue stragglers may be field contaminations, and some may be confused with the rare blue horizontal-branch stars in this cluster.

  2. Ion-counting nanodosimetry: current status and future applications.

    Science.gov (United States)

    Schulte, R; Bashkirov, V; Garty, G; Leloup, C; Shchemelinin, S; Breskin, A; Chechik, R; Milligan, J; Grosswendt, B

    2003-12-01

    There is a growing interest in the study of interactions of ionizing radiation with condensed matter at the nanometer level. The motivation for this research is the hypothesis that the number of ionizations occurring within short segments of DNA-size subvolumes is a major factor determining the biological effectiveness of ionizing radiation. A novel dosimetry technique, called nanodosimetry, measures the spatial distribution of individual ionizations in an irradiated low-pressure gas model of DNA. The measurement of nanodosimetric event size spectra may enable improved characterization of radiation quality, with applications in proton and charged-particle therapy, radiation protection, and space research. We describe an ion-counting nanodosimeter developed for measuring radiation-induced ionization clusters in small, wall-less low-pressure gas volumes, simulating short DNA segments. It measures individual radiation-induced ions, deposited in 1 Torr propane within a tissue-equivalent cylindrical volume of 2-4 nm diameter and up to 100 nm length. We present first ionization cluster size distributions obtained with 13.6 MeV protons, 4.25 MeV alpha particles and 24.8 MeV carbon nuclei in propane; they correspond to a wide LET range of 4-500 keV/microm. We are currently developing plasmid-based assays to characterize the local clustering of DNA damage with biological methods. First results demonstrate that there is increasing complexity of DNA damage with increasing LET. Systematic comparison of biological and nanodosimetric data will help us to validate biophysical models predicting radiation quality based on nanodosimetric spectra. Possible applications for charged particle radiation therapy planning are discussed.

  3. Oscillations in counting statistics

    CERN Document Server

    Wilk, Grzegorz

    2016-01-01

    The very large transverse momenta and large multiplicities available in present LHC experiments on pp collisions allow a much closer look at the corresponding distributions. Some time ago we discussed a possible physical meaning of apparent log-periodic oscillations showing up in p_T distributions (suggesting that the exponent of the observed power-like behavior is complex). In this talk we concentrate on another example of oscillations, this time connected with multiplicity distributions P(N). We argue that some combinations of the experimentally measured values of P(N) (satisfying the recurrence relations used in the description of cascade-stochastic processes in quantum optics) exhibit distinct oscillatory behavior, not observed in the usual Negative Binomial Distributions used to fit data. These oscillations provide yet another example of oscillations seen in counting statistics in many different, apparently very disparate branches of physics further demonstrating the universality of this phenomenon.

  4. Number Games, Magnitude Representation, and Basic Number Skills in Preschoolers

    Science.gov (United States)

    Whyte, Jemma Catherine; Bull, Rebecca

    2008-01-01

    The effect of 3 intervention board games (linear number, linear color, and nonlinear number) on young children's (mean age = 3.8 years) counting abilities, number naming, magnitude comprehension, accuracy in number-to-position estimation tasks, and best-fit numerical magnitude representations was examined. Pre- and posttest performance was…

  5. Number Games, Magnitude Representation, and Basic Number Skills in Preschoolers

    Science.gov (United States)

    Whyte, Jemma Catherine; Bull, Rebecca

    2008-01-01

    The effect of 3 intervention board games (linear number, linear color, and nonlinear number) on young children's (mean age = 3.8 years) counting abilities, number naming, magnitude comprehension, accuracy in number-to-position estimation tasks, and best-fit numerical magnitude representations was examined. Pre- and posttest performance was…

  6. If Not Only Numbers Count: Allocation of Equal Chances

    Directory of Open Access Journals (Sweden)

    Marlies Ahlert

    2009-01-01

    Full Text Available It is assumed that medical guidelines specify the appropriate amount of a divisible good which each individual should receive. Individual requirements and probabilities that the treatment is successful if an appropriate amount is received differ. The same applies to the success probabilities if individuals are inadequately treated. If supply is insufficient to serve all with appropriate amounts an allocation decision is necessary. We define probabilistic allocation rules that allocate chances of successful treatment to all individuals. We analyse a specific random allocation rule that assigns maximal equal gains of chances. We characterize the equal gain rule axiomatically.

  7. Super-Resolution Imaging and Quantitative Analysis of Membrane Protein/Lipid Raft Clustering Mediated by Cell-Surface Self-Assembly of Hybrid Nanoconjugates.

    Science.gov (United States)

    Hartley, Jonathan M; Chu, Te-Wei; Peterson, Eric M; Zhang, Rui; Yang, Jiyuan; Harris, Joel; Kopeček, Jindřich

    2015-08-17

    Super-resolution imaging was used to quantify organizational changes in the plasma membrane after treatment with hybrid nanoconjugates. The nanoconjugates crosslinked CD20 on the surface of malignant B cells, thereby inducing apoptosis. Super-resolution images were analyzed by using pair-correlation analysis to determine cluster size and to count the average number of molecules in the clusters. The role of lipid rafts was investigated by pre-treating cells with a cholesterol chelator and actin destabilizer to prevent lipid raft formation. Lipid raft cluster size correlated with apoptosis induction after treatment with the nanoconjugates. Lipid raft clusters had radii of ∼ 200 nm in cells treated with the hybrid nanoconjugates. Super-resolution images provided precise molecule location coordinates that could be used to determine density of bound conjugates, cluster size, and number of molecules per cluster.

  8. Automated counting of white blood cells in synovial fluid.

    NARCIS (Netherlands)

    R. de Jonge (Robert); R.W. Brouwer (Reinoud); M. Smit (Marij); M. de Frankrijker-Merkestijn; R.J. Dolhain; J.M.W. Hazes (Mieke); A.W. van Toorenenbergen (Albert); J. Lindemans (Jan)

    2004-01-01

    textabstractOBJECTIVES: To evaluate the performance of automated leucocyte (white blood cell; WBC) counting by comparison with manual counting. METHODS: The number of WBC was determined in heparinized synovial fluid samples by the use of (i) a standard urine cytometer (Kova) and a

  9. Automatic counting and classification of bacterial colonies using hyperspectral imaging

    Science.gov (United States)

    Detection and counting of bacterial colonies on agar plates is a routine microbiology practice to get a rough estimate of the number of viable cells in a sample. There have been a variety of different automatic colony counting systems and software algorithms mainly based on color or gray-scale pictu...

  10. Magnitude Representations and Counting Skills in Preschool Children

    Science.gov (United States)

    Batchelor, Sophie; Keeble, Sarah; Gilmore, Camilla

    2015-01-01

    When children learn to count, they map newly acquired symbolic representations of number onto preexisting nonsymbolic representations. The nature and timing of this mapping is currently unclear. Some researchers have suggested this mapping process helps children understand the cardinal principle of counting, while other evidence suggests that this…

  11. Probing dark energy with the next generation X-ray surveys of galaxy clusters

    CERN Document Server

    Sartoris, B; Rosati, P; Weller, J

    2011-01-01

    We present forecasts on the capability of future wide-area high-sensitivity X-ray surveys of galaxy clusters to yield constraints on the parameters defining the Dark Energy (DE) equation of state (EoS). Our analysis is carried out for future X-ray surveys which have enough sensitivity to provide accurate measurements of X-ray mass proxies and Fe-line based redshifts for about 2x10^4 clusters. We base our analysis on the Fisher Matrix formalism, by combining information on the cluster number counts and power spectrum, also including, for the first time in the analysis of the large scale cluster distribution, the effect of linear redshift-space distortions (RSDs). This study is performed with the main purpose of dissecting the cosmological information provided by geometrical and growth tests, which are both included in the analysis of number counts and clustering of galaxy clusters. We compare cosmological constraints obtained by assuming different levels of prior knowledge of the parameters which define the ob...

  12. Analysis of forest fires spatial clustering using local fractal measure

    Science.gov (United States)

    Kanevski, Mikhail; Rochat, Mikael; Timonin, Vadim

    2013-04-01

    The research deals with an application of local fractal measure - local sandbox counting or mass counting, for the characterization of patterns of spatial clustering. The main application concerns the simulated (random patterns within validity domain in forest regions) and real data (forest fires in Ticino, Switzerland) case studies. The global patterns of spatial clustering of forest fires were extensively studied using different topological (nearest-neighbours, Voronoi polygons), statistical (Ripley's k-function, Morisita diagram) and fractal/multifractal measures (box-counting, sandbox counting, lacunarity) (Kanevski, 2008). Generalizations of these measures to functional ones can reveal the structure of the phenomena, e.g. burned areas. All these measures are valuable and complementary tools to study spatial clustering. Moreover, application of the validity domain (complex domain where phenomena is studied) concept helps in understanding and interpretation of the results. In the present paper a sandbox counting method was applied locally, i.e. each point of ignition was considered as a centre of events counting with an increasing search radius. Then, the local relationships between the radius and the number of ignition points within the given radius were examined. Finally, the results are mapped using an interpolation algorithm for the visualization and analytical purposes. Both 2d (X,Y) and 3d (X,Y,Z) cases were studied and compared. Local "fractal" study gives an interesting spatially distributed picture of clustering. The real data case study was compared with a reference homogeneous pattern - complete spatial randomness. The difference between two patterns clearly indicates the regions with important spatial clustering. An extension to the local functional measure was applied taking into account the surface of burned area, i.e. by analysing only data with the fires above some threshold of burned area. Such analysis is similar to marked point processes and

  13. Spatial cluster modelling

    CERN Document Server

    Lawson, Andrew B

    2002-01-01

    Research has generated a number of advances in methods for spatial cluster modelling in recent years, particularly in the area of Bayesian cluster modelling. Along with these advances has come an explosion of interest in the potential applications of this work, especially in epidemiology and genome research. In one integrated volume, this book reviews the state-of-the-art in spatial clustering and spatial cluster modelling, bringing together research and applications previously scattered throughout the literature. It begins with an overview of the field, then presents a series of chapters that illuminate the nature and purpose of cluster modelling within different application areas, including astrophysics, epidemiology, ecology, and imaging. The focus then shifts to methods, with discussions on point and object process modelling, perfect sampling of cluster processes, partitioning in space and space-time, spatial and spatio-temporal process modelling, nonparametric methods for clustering, and spatio-temporal ...

  14. Counting pairs of faint galaxies

    CERN Document Server

    Woods, D; Richer, H B; Woods, David; Fahlman, Gregory G; Richer, Harvey B

    1995-01-01

    The number of close pairs of galaxies observed to faint magnitude limits, when compared to nearby samples, determines the interaction or merger rate as a function of redshift. The prevalence of mergers at intermediate redshifts is fundamental to understanding how galaxies evolve and the relative population of galaxy types. Mergers have been used to explain the excess of galaxies in faint blue counts above the numbers expected from no-evolution models. Using deep CFHT (I\\leq24) imaging of a ``blank'' field we find a pair fraction which is consistent with the galaxies in our sample being randomly distributed with no significant excess of ``physical'' close pairs. This is contrary to the pair fraction of 34\\%\\pm9\\% found by Burkey {\\it et al.} for similar magnitude limits and using an identical approach to the pair analysis. Various reasons for this discrepancy are discussed. Colors and morphologies of our close pairs are consistent with the bulk of them being random superpositions although, as indicators of int...

  15. Cluster headache

    Science.gov (United States)

    Histamine headache; Headache - histamine; Migrainous neuralgia; Headache - cluster; Horton's headache; Vascular headache - cluster ... A cluster headache begins as a severe, sudden headache. The headache commonly strikes 2 to 3 hours after you fall ...

  16. Cluster Forests

    CERN Document Server

    Yan, Donghui; Jordan, Michael I

    2011-01-01

    Inspired by Random Forests (RF) in the context of classification, we propose a new clustering ensemble method---Cluster Forests (CF). Geometrically, CF randomly probes a high-dimensional data cloud to obtain "good local clusterings" and then aggregates via spectral clustering to obtain cluster assignments for the whole dataset. The search for good local clusterings is guided by a cluster quality measure $\\kappa$. CF progressively improves each local clustering in a fashion that resembles the tree growth in RF. Empirical studies on several real-world datasets under two different performance metrics show that CF compares favorably to its competitors. Theoretical analysis shows that the $\\kappa$ criterion is shown to grow each local clustering in a desirable way---it is "noise-resistant." A closed-form expression is obtained for the mis-clustering rate of spectral clustering under a perturbation model, which yields new insights into some aspects of spectral clustering.

  17. LAWRENCE RADIATION LABORATORY COUNTING HANDBOOK

    Energy Technology Data Exchange (ETDEWEB)

    Group, Nuclear Instrumentation

    1966-10-01

    The Counting Handbook is a compilation of operational techniques and performance specifications on counting equipment in use at the Lawrence Radiation Laboratory, Berkeley. Counting notes have been written from the viewpoint of the user rather than that of the designer or maintenance man. The only maintenance instructions that have been included are those that can easily be performed by the experimenter to assure that the equipment is operating properly.

  18. Counting Frequencies from Zotero Items

    Directory of Open Access Journals (Sweden)

    Spencer Roberts

    2013-04-01

    Full Text Available In Counting Frequencies you learned how to count the frequency of specific words in a list using python. In this lesson, we will expand on that topic by showing you how to get information from Zotero HTML items, save the content from those items, and count the frequencies of words. It may be beneficial to look over the previous lesson before we begin.

  19. Haida Numbers and Calculation.

    Science.gov (United States)

    Cogo, Robert

    Experienced traders in furs, blankets, and other goods, the Haidas of the 1700's had a well-developed decimal system for counting and calculating. Their units of linear measure included the foot, yard, and fathom, or six feet. This booklet lists the numbers from 1 to 20 in English and Haida; explains the Haida use of ten, hundred, and thousand…

  20. Eosinophil count - absolute

    Science.gov (United States)

    ... Abnormal Results Mean A high number of eosinophils (eosinophilia) are often linked to a variety of disorders. ... Accessed March 29, 2017. Klion AD, Weller PF. Eosinophilia and eosinophil-related disorders. In: Adkinson NF, Bochner ...

  1. Star Clusters

    OpenAIRE

    Gieles, M.

    1993-01-01

    Star clusters are observed in almost every galaxy. In this thesis we address several fundamental problems concerning the formation, evolution and disruption of star clusters. From observations of (young) star clusters in the interacting galaxy M51, we found that clusters are formed in complexes of stars and star clusters. These complexes share similar properties with giant molecular clouds, from which they are formed. Many (70%) of the young clusters will not survive the fist 10 Myr, due to t...

  2. Accurate Atom Counting in Mesoscopic Ensembles

    CERN Document Server

    Hume, D B; Joos, M; Muessel, W; Strobel, H; Oberthaler, M K

    2013-01-01

    Many cold atom experiments rely on precise atom number detection, especially in the context of quantum-enhanced metrology where effects at the single particle level are important. Here, we investigate the limits of atom number counting via resonant fluorescence detection for mesoscopic samples of trapped atoms. We characterize the precision of these fluorescence measurements beginning from the single-atom level up to more than one thousand. By investigating the primary noise sources, we obtain single-atom resolution for atom numbers as high as 1200. This capability is an essential prerequisite for future experiments with highly entangled states of mesoscopic atomic ensembles.

  3. Accurate Atom Counting in Mesoscopic Ensembles

    Science.gov (United States)

    Hume, D. B.; Stroescu, I.; Joos, M.; Muessel, W.; Strobel, H.; Oberthaler, M. K.

    2013-12-01

    Many cold atom experiments rely on precise atom number detection, especially in the context of quantum-enhanced metrology where effects at the single particle level are important. Here, we investigate the limits of atom number counting via resonant fluorescence detection for mesoscopic samples of trapped atoms. We characterize the precision of these fluorescence measurements beginning from the single-atom level up to more than one thousand. By investigating the primary noise sources, we obtain single-atom resolution for atom numbers as high as 1200. This capability is an essential prerequisite for future experiments with highly entangled states of mesoscopic atomic ensembles.

  4. Accurate atom counting in mesoscopic ensembles.

    Science.gov (United States)

    Hume, D B; Stroescu, I; Joos, M; Muessel, W; Strobel, H; Oberthaler, M K

    2013-12-20

    Many cold atom experiments rely on precise atom number detection, especially in the context of quantum-enhanced metrology where effects at the single particle level are important. Here, we investigate the limits of atom number counting via resonant fluorescence detection for mesoscopic samples of trapped atoms. We characterize the precision of these fluorescence measurements beginning from the single-atom level up to more than one thousand. By investigating the primary noise sources, we obtain single-atom resolution for atom numbers as high as 1200. This capability is an essential prerequisite for future experiments with highly entangled states of mesoscopic atomic ensembles.

  5. SUMS Counts-Related Projects

    Data.gov (United States)

    Social Security Administration — Staging Instance for all SUMs Counts related projects including: Redeterminations/Limited Issue, Continuing Disability Resolution, CDR Performance Measures, Initial...

  6. The Acquisition of Counting Skill in Preschooler

    Directory of Open Access Journals (Sweden)

    Kadir Çakır

    2013-03-01

    Full Text Available Abstract- The aim of this study was to find out more information on the acquisition of counting skill in preschool children. For this purpose, children’s judgment of acceptability of a counting activity was used to investigate whether children’s counting skills are governed by their implicit knowledge of a number of counting principles. Data showed that children easily recognized the violation of one or more counting principles in a one’s application of counting principles in sequences of English and Turkish count words, implying that children have the understanding of counting principles. The sessions on counting in Turkish make it very likely that the children were responding to violations of rules rather than merely violation of well-learning of count words. These results give additional support to the assumption that there are innate counting principles that rule young children’s counting. Keywords: counting principles, error-detection task, mathematical development. Özet- Okul Öncesi Çocuklarda Sayma İlkeleri. Bu çalışmada çocukların bir sayma etkinliğinin geçerli olup olmadığı hakkındaki yargıları kullanılarak, sayma becerisinin doğuştan sahip olunan bir dizi örtük ilkeler tarafından yönlendirilip yönlendirilmediği incelenmiştir. Bu amaç doğrultusunda, bir grup okul öncesi çocuklardan videodan izledikleri bir aktör çocuğun hem anadilinde (İngilizce hem de bilmedikleri bir yabancı dilde (Türkçe yaptığı farklı hatalar içeren sayma serilerinin doğru veya yanlış olup olmadığı belirtmesi istenmiştir. Elde edilen sonuçlar çocukların sayma etkinliklerine rehberlik eden doğuştan getirdikleri örtük “sayma ilkelerine” sahip olduklarına ilişkin görüşleri destekler yönündedir. Örneğin, gerek İngilizce gerekse Türkçe sayma serilerinde, “standart (doğru sayma” serisi diğer tüm serilere göre anlamlı ölçüde “doğru” bir sayma olarak değerlendirilirken, T

  7. Numbers their history and meaning

    CERN Document Server

    Flegg, Graham

    2003-01-01

    Readable, jargon-free book examines the earliest endeavors to count and record numbers, initial attempts to solve problems by using equations, and origins of infinite cardinal arithmetic. "Surprisingly exciting." - Choice.

  8. Does Each Atom Count in the Reactivity of Vanadia Nanoclusters?

    Science.gov (United States)

    Zhang, Mei-Qi; Zhao, Yan-Xia; Liu, Qing-Yu; Li, Xiao-Na; He, Sheng-Gui

    2017-01-11

    Vanadium oxide cluster anions (V2O5)nVxOy(-) (n = 1-31; x = 0, 1; and x + y ≤ 5) with different oxygen deficiencies (Δ = 2y-1-5x = 0, ± 1, and ±2) have been prepared by laser ablation and reacted to abstract hydrogen atoms from alkane molecules (n-butane) in a fast flow reactor. When the cluster size n is less than 25, the Δ = 1 series [(V2O5)nO(-) clusters] that can contain atomic oxygen radical anions (O(•-)) generally have much higher reactivity than the other four cluster series (Δ = -2, -1, 0, and 2), indicating that each atom counts in the hydrogen-atom abstraction (HAA) reactivity. Unexpectedly, all of the five cluster series have similar HAA reactivity when the cluster size is greater than 25. The critical dimension of vanadia particles separating the cluster behavior (each atom counts) from the bulk behavior (each atom contributes a little part) is thus about 1.6 nm (∼V50O125). The strong electron-phonon coupling of the vanadia particles has been proposed to create the O(•-) radicals (V(5+) = O(2-)+ heat → V(4+)-O(•-)) for the n > 25 clusters with Δ = -2, -1, 0, and 2. Such a mechanism is supported by a comparative study with the scandium system [(Sc2O3)nScxOy(-) (n = 1-29; x = 0, 1; and x + y ≤ 4)] for which the Δ = 1 series [(Sc2O3)nO(-) clusters] always have much higher HAA reactivity than the other cluster series.

  9. Cluster fusion algorithm: application to Lennard-Jones clusters

    DEFF Research Database (Denmark)

    Solov'yov, Ilia; Solov'yov, Andrey V.; Greiner, Walter

    2008-01-01

    paths up to the cluster size of 150 atoms. We demonstrate that in this way all known global minima structures of the Lennard-Jones clusters can be found. Our method provides an efficient tool for the calculation and analysis of atomic cluster structure. With its use we justify the magic number sequence...... for the clusters of noble gas atoms and compare it with experimental observations. We report the striking correspondence of the peaks in the dependence of the second derivative of the binding energy per atom on cluster size calculated for the chain of the Lennard-Jones clusters based on the icosahedral symmetry......We present a new general theoretical framework for modelling the cluster structure and apply it to description of the Lennard-Jones clusters. Starting from the initial tetrahedral cluster configuration, adding new atoms to the system and absorbing its energy at each step, we find cluster growing...

  10. Cluster fusion algorithm: application to Lennard-Jones clusters

    DEFF Research Database (Denmark)

    Solov'yov, Ilia; Solov'yov, Andrey V.; Greiner, Walter

    2006-01-01

    paths up to the cluster size of 150 atoms. We demonstrate that in this way all known global minima structures of the Lennard-Jones clusters can be found. Our method provides an efficient tool for the calculation and analysis of atomic cluster structure. With its use we justify the magic number sequence...... for the clusters of noble gas atoms and compare it with experimental observations. We report the striking correspondence of the peaks in the dependence of the second derivative of the binding energy per atom on cluster size calculated for the chain of the Lennard-Jones clusters based on the icosahedral symmetry......We present a new general theoretical framework for modelling the cluster structure and apply it to description of the Lennard-Jones clusters. Starting from the initial tetrahedral cluster configuration, adding new atoms to the system and absorbing its energy at each step, we find cluster growing...

  11. COUNTING FAIR NEAR-TRIANGULATIONS ON THE DISC

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    In this paper various kinds of fair near-triangulations are enumerated and several other types of near-triangulations are counted with the root-face valency,the number of edges and faces as the parameters.

  12. Efficient Prime Counting and the Chebyshev Primes

    Directory of Open Access Journals (Sweden)

    Michel Planat

    2013-01-01

    Full Text Available The function where is the logarithm integral and the number of primes up to is well known to be positive up to the (very large Skewes' number. Likewise, according to Robin's work, the functions and , where and are Chebyshev summatory functions, are positive if and only if Riemann hypothesis (RH holds. One introduces the jump function at primes and one investigates , , and . In particular, , and for . Besides, for any odd , an infinite set of the so-called Chebyshev primes. In the context of RH, we introduce the so-called Riemann primes as champions of the function (or of the function . Finally, we find a good prime counting function , that is found to be much better than the standard Riemann prime counting function.

  13. Calling Dunbar's Numbers

    CERN Document Server

    MacCarron, Pádraig; Dunbar, Robin

    2016-01-01

    The social brain hypothesis predicts that humans have an average of about 150 relationships at any given time. Within this 150, there are layers of friends of an ego, where the number of friends in a layer increases as the emotional closeness decreases. Here we analyse a mobile phone dataset, firstly, to ascertain whether layers of friends can be identified based on call frequency. We then apply different clustering algorithms to break the call frequency of egos into clusters and compare the number of alters in each cluster with the layer size predicted by the social brain hypothesis. In this dataset we find strong evidence for the existence of a layered structure. The clustering yields results that match well with previous studies for the innermost and outermost layers, but for layers in between we observe large variability.

  14. Clustering of resting state networks.

    Directory of Open Access Journals (Sweden)

    Megan H Lee

    Full Text Available BACKGROUND: The goal of the study was to demonstrate a hierarchical structure of resting state activity in the healthy brain using a data-driven clustering algorithm. METHODOLOGY/PRINCIPAL FINDINGS: The fuzzy-c-means clustering algorithm was applied to resting state fMRI data in cortical and subcortical gray matter from two groups acquired separately, one of 17 healthy individuals and the second of 21 healthy individuals. Different numbers of clusters and different starting conditions were used. A cluster dispersion measure determined the optimal numbers of clusters. An inner product metric provided a measure of similarity between different clusters. The two cluster result found the task-negative and task-positive systems. The cluster dispersion measure was minimized with seven and eleven clusters. Each of the clusters in the seven and eleven cluster result was associated with either the task-negative or task-positive system. Applying the algorithm to find seven clusters recovered previously described resting state networks, including the default mode network, frontoparietal control network, ventral and dorsal attention networks, somatomotor, visual, and language networks. The language and ventral attention networks had significant subcortical involvement. This parcellation was consistently found in a large majority of algorithm runs under different conditions and was robust to different methods of initialization. CONCLUSIONS/SIGNIFICANCE: The clustering of resting state activity using different optimal numbers of clusters identified resting state networks comparable to previously obtained results. This work reinforces the observation that resting state networks are hierarchically organized.

  15. Reference counting for reversible languages

    DEFF Research Database (Denmark)

    Mogensen, Torben Ægidius

    2014-01-01

    deallocation. This requires the language to be linear: A pointer can not be copied and it can only be eliminated by deallocating the node to which it points. We overcome this limitation by adding reference counts to nodes: Copying a pointer to a node increases the reference count of the node and eliminating...

  16. Coinductive counting with weighted automata

    NARCIS (Netherlands)

    Rutten, J.J.M.M.

    2002-01-01

    A general methodology is developed to compute the solution of a wide variety of basic counting problems in a uniform way: (1) the objects to be counted are enumerated by means of an infinite weighted automaton; (2) the automaton is reduced by means of the quantitative notion of stream bisimulation;

  17. Low White Blood Cell Count

    Science.gov (United States)

    Symptoms Low white blood cell count By Mayo Clinic Staff A low white blood cell count (leukopenia) is a decrease in disease-fighting cells ( ... a decrease in a certain type of white blood cell (neutrophil). The definition of low white blood cell ...

  18. Stellar populations in star clusters

    CERN Document Server

    Li, Chengyuan; Deng, Licai

    2016-01-01

    Stellar populations contain the most important information about star clus- ter formation and evolution. Until several decades ago, star clusters were believed to be ideal laboratories for studies of simple stellar populations (SSPs). However, discoveries of multiple stellar populations in Galactic globular clusters have expanded our view on stellar populations in star clusters. They have simultaneously generated a number of controversies, particularly as to whether young star clusters may have the same origin as old globular clusters. In addition, extensive studies have revealed that the SSP scenario does not seem to hold for some intermediate-age and young star clusters either, thus making the origin of multiple stellar populations in star clusters even more complicated. Stellar population anomalies in numerous star clusters are well-documented, implying that the notion of star clusters as true SSPs faces serious challenges. In this review, we focus on stellar populations in massive clusters with different ...

  19. The adventure of numbers

    CERN Document Server

    Godefroy, Gilles

    2004-01-01

    Numbers are fascinating. The fascination begins in childhood, when we first learn to count. It continues as we learn arithmetic, algebra, geometry, and so on. Eventually, we learn that numbers not only help us to measure the world, but also to understand it and, to some extent, to control it. In The Adventure of Numbers, Gilles Godefroy follows the thread of our expanding understanding of numbers to lead us through the history of mathematics. His goal is to share the joy of discovering and understanding this great adventure of the mind. The development of mathematics has been punctuated by a n

  20. Hanford whole body counting manual

    Energy Technology Data Exchange (ETDEWEB)

    Palmer, H.E.; Brim, C.P.; Rieksts, G.A.; Rhoads, M.C.

    1987-05-01

    This document, a reprint of the Whole Body Counting Manual, was compiled to train personnel, document operation procedures, and outline quality assurance procedures. The current manual contains information on: the location, availability, and scope of services of Hanford's whole body counting facilities; the administrative aspect of the whole body counting operation; Hanford's whole body counting facilities; the step-by-step procedure involved in the different types of in vivo measurements; the detectors, preamplifiers and amplifiers, and spectroscopy equipment; the quality assurance aspect of equipment calibration and recordkeeping; data processing, record storage, results verification, report preparation, count summaries, and unit cost accounting; and the topics of minimum detectable amount and measurement accuracy and precision. 12 refs., 13 tabs.

  1. An analytical model of crater count equilibrium

    Science.gov (United States)

    Hirabayashi, Masatoshi; Minton, David A.; Fassett, Caleb I.

    2017-06-01

    Crater count equilibrium occurs when new craters form at the same rate that old craters are erased, such that the total number of observable impacts remains constant. Despite substantial efforts to understand this process, there remain many unsolved problems. Here, we propose an analytical model that describes how a heavily cratered surface reaches a state of crater count equilibrium. The proposed model formulates three physical processes contributing to crater count equilibrium: cookie-cutting (simple, geometric overlap), ejecta-blanketing, and sandblasting (diffusive erosion). These three processes are modeled using a degradation parameter that describes the efficiency for a new crater to erase old craters. The flexibility of our newly developed model allows us to represent the processes that underlie crater count equilibrium problems. The results show that when the slope of the production function is steeper than that of the equilibrium state, the power law of the equilibrium slope is independent of that of the production function slope. We apply our model to the cratering conditions in the Sinus Medii region and at the Apollo 15 landing site on the Moon and demonstrate that a consistent degradation parameterization can successfully be determined based on the empirical results of these regions. Further developments of this model will enable us to better understand the surface evolution of airless bodies due to impact bombardment.

  2. Approximately Counting Embeddings into Random Graphs

    CERN Document Server

    Furer, Martin

    2008-01-01

    Let H be a graph, and let C(H,G) be the number of (subgraph isomorphic) copies of H contained in a graph G. We investigate the fundamental problem of estimating C(H,G). Previous results cover only a few specific instances of this general problem, for example, the case when H has degree at most one (monomer-dimer problem). In this paper, we present the first general subcase of the subgraph isomorphism counting problem which is almost always efficiently approximable. The results rely on a new graph decomposition technique. Informally, the decomposition is a labeling of the vertices generating a sequence of bipartite graphs. The decomposition permits us to break the problem of counting embeddings of large subgraphs into that of counting embeddings of small subgraphs. Using this method, we present a simple randomized algorithm for the counting problem. For all decomposable graphs H and all graphs G, the algorithm is an unbiased estimator. Furthermore, for all graphs H having a decomposition where each of the bipa...

  3. Aspects of situated cognition in embodied numerosity: the case of finger counting.

    Science.gov (United States)

    Wasner, Mirjam; Moeller, Korbinian; Fischer, Martin H; Nuerk, Hans-Christoph

    2014-08-01

    Numerical cognitions such as spatial-numerical associations have been observed to be influenced by grounded, embodied and situated factors. For the case of finger counting, grounded and embodied influences have been reported. However, situated influences, e.g., that reported counting habits change with perception and action within a given situation, have not been systematically examined. To pursue the issue of situatedness of reported finger-counting habits, 458 participants were tested in three separate groups: (1) spontaneous condition: counting with both hands available, (2) perceptual condition: counting with horizontal (left-to-right) perceptual arrangement of fingers (3) perceptual and proprioceptive condition: counting with horizontal (left-to-right) perceptual arrangement of fingers and with busy dominant hand. Report of typical counting habits differed strongly between the three conditions. 28 % reported to start counting with the left hand in the spontaneous counting condition (1), 54 % in the perceptual condition (2) and 62 % in the perceptual and proprioceptive condition (3). Additionally, all participants in the spontaneous counting group showed a symmetry-based counting pattern (with the thumb as number 6), while in the two other groups, a considerable number of participants exhibited a spatially continuous counting pattern (with the pinkie as number 6). Taken together, the study shows that reported finger-counting habits depend on the perceptual and proprioceptive situation and thus are strongly influenced by situated cognition. We suggest that this account reconciles apparently contradictory previous findings of different counting preferences regarding the starting hand in different examination situations.

  4. Counting gluings of octahedra

    CERN Document Server

    Bonzom, Valentin

    2016-01-01

    Three--dimensional colored triangulations are gluings of tetrahedra whose faces carry the colors 0, 1, 2, 3 and in which the attaching maps between tetrahedra are defined using the colors. This framework makes it possible to generalize the notion of two--dimensional $2p$--angulations to three dimensions in a way which is suitable for combinatorics and enumeration. In particular, universality classes of three--dimensional triangulations can be investigated within this framework. Here we study colored triangulations obtained by gluing octahedra. Those which maximize the number of edges at fixed number of octahedra are fully characterized and are shown to have the topology of the 3--sphere. They are further shown to be in bijection with a family of trees, a result which is confirmed by the exact enumeration.

  5. Counting acyclic hypergraphs

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Acyclic hypergraphs are analogues of forests in graphs. They arevery useful in the design of databases. The number of distinct acyclic uniform hypergraphs with n labeled vertices is studied. With the aid of the principle of inclusion-exclusion, two formulas are presented. One is the explicit formula for strict (d)-connected acyclic hypergraphs, the other is the recurrence formula for linear acyclic hypergraphs.

  6. Statistical connection of peak counts to power spectrum and moments in weak lensing field

    CERN Document Server

    Shirasaki, Masato

    2016-01-01

    The number density of local maxima of weak lensing field, referred to as weak-lensing peak counts, can be used as a cosmological probe. However, its relevant cosmological information is still unclear. We study the relationship between the peak counts and other statistics in weak lensing field by using 1000 ray-tracing simulations. We construct a local transformation of lensing field $\\cal K$ to a new Gaussian field $y$, named local-Gaussianized transformation. We calibrate the transformation with numerical simulations so that the one-point distribution and the power spectrum of $\\cal K$ can be reproduced from a single Gaussian field $y$ and monotonic relation between $y$ and $\\cal K$. Therefore, the correct information of two-point clustering and any order of moments in weak lensing field should be preserved under local-Gaussianized transformation. We then examine if local-Gaussianized transformation can predict weak-lensing peak counts in simulations. The local-Gaussianized transformation is insufficient to ...

  7. Weighted Clustering

    DEFF Research Database (Denmark)

    Ackerman, Margareta; Ben-David, Shai; Branzei, Simina

    2012-01-01

    We investigate a natural generalization of the classical clustering problem, considering clustering tasks in which different instances may have different weights.We conduct the first extensive theoretical analysis on the influence of weighted data on standard clustering algorithms in both...... the partitional and hierarchical settings, characterizing the conditions under which algorithms react to weights. Extending a recent framework for clustering algorithm selection, we propose intuitive properties that would allow users to choose between clustering algorithms in the weighted setting and classify...

  8. High Count Rate Single Photon Counting Detector Array Project

    Data.gov (United States)

    National Aeronautics and Space Administration — An optical communications receiver requires efficient and high-rate photon-counting capability so that the information from every photon, received at the aperture,...

  9. A new sieve for distinct coordinate counting

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    We present a new sieve for the distinct coordinate counting problem.This significantly improves the classical inclusion-exclusion sieve for this problem,in the sense that the number of terms is reduced from 2(k 2) to k!,and reduced further to p(k) in the symmetric case,where p(k) denotes the number of partitions of k.As an illustration of applications,we give an in-depth study of a basic example arising from coding theory and graph theory.

  10. Tune Your Brown Clustering, Please

    DEFF Research Database (Denmark)

    Derczynski, Leon; Chester, Sean; Bøgh, Kenneth Sejdenfaden

    2015-01-01

    explore the dynamic between the input corpus size, chosen number of classes, and quality of the resulting clusters, which has an impact for any approach using Brown clustering. In every scenario that we examine, our results reveal that the values most commonly used for the clustering are sub-optimal....

  11. Vote Counting as Mathematical Proof

    DEFF Research Database (Denmark)

    Schürmann, Carsten; Pattinson, Dirk

    2015-01-01

    Trust in the correctness of an election outcome requires proof of the correctness of vote counting. By formalising particular voting protocols as rules, correctness of vote counting amounts to verifying that all rules have been applied correctly. A proof of the outcome of any particular election......-based formalisation of voting protocols inside a theorem prover, we synthesise vote counting programs that are not only provably correct, but also produce independently verifiable certificates. These programs are generated from a (formal) proof that every initial set of ballots allows to decide the election winner...

  12. White blood cell counting system

    Science.gov (United States)

    1972-01-01

    The design, fabrication, and tests of a prototype white blood cell counting system for use in the Skylab IMSS are presented. The counting system consists of a sample collection subsystem, sample dilution and fluid containment subsystem, and a cell counter. Preliminary test results show the sample collection and the dilution subsystems are functional and fulfill design goals. Results for the fluid containment subsystem show the handling bags cause counting errors due to: (1) adsorption of cells to the walls of the container, and (2) inadequate cleaning of the plastic bag material before fabrication. It was recommended that another bag material be selected.

  13. High Reproducibility of ELISPOT Counts from Nine Different Laboratories

    Directory of Open Access Journals (Sweden)

    Srividya Sundararaman

    2015-01-01

    Full Text Available The primary goal of immune monitoring with ELISPOT is to measure the number of T cells, specific for any antigen, accurately and reproducibly between different laboratories. In ELISPOT assays, antigen-specific T cells secrete cytokines, forming spots of different sizes on a membrane with variable background intensities. Due to the subjective nature of judging maximal and minimal spot sizes, different investigators come up with different numbers. This study aims to determine whether statistics-based, automated size-gating can harmonize the number of spot counts calculated between different laboratories. We plated PBMC at four different concentrations, 24 replicates each, in an IFN-γ ELISPOT assay with HCMV pp65 antigen. The ELISPOT plate, and an image file of the plate was counted in nine different laboratories using ImmunoSpot® Analyzers by (A Basic Count™ relying on subjective counting parameters set by the respective investigators and (B SmartCount™, an automated counting protocol by the ImmunoSpot® Software that uses statistics-based spot size auto-gating with spot intensity auto-thresholding. The average coefficient of variation (CV for the mean values between independent laboratories was 26.7% when counting with Basic Count™, and 6.7% when counting with SmartCount™. Our data indicates that SmartCount™ allows harmonization of counting ELISPOT results between different laboratories and investigators.

  14. Extreme value statistics of weak lensing shear peak counts

    CERN Document Server

    Reischke, Robert; Bartelmann, Matthias

    2015-01-01

    The statistics of peaks in weak gravitational lensing maps is a promising technique to constrain cosmological parameters in present and future surveys. Here we investigate its power when using general extreme value statistics which is very sensitive to the exponential tail of the halo mass function. To this end, we use an analytic method to quantify the number of weak lensing peaks caused by galaxy clusters, large-scale structures and observational noise. Doing so, we further improve the method in the regime of high signal-to-noise ratios dominated by non-linear structures by accounting for the embedding of those counts into the surrounding shear caused by large scale structures. We derive the extreme value and order statistics for both over-densities (positive peaks) and under-densities (negative peaks) and provide an optimized criterion to split a wide field survey into sub-fields in order to sample the distribution of extreme values such that the expected objects causing the largest signals are mostly due ...

  15. Capabilities of R Package mixAK for Clustering Based on Multivariate Continuous and Discrete Longitudinal Data

    Directory of Open Access Journals (Sweden)

    Arnošt Komárek

    2014-09-01

    Full Text Available R package mixAK originally implemented routines primarily for Bayesian estimation of finite normal mixture models for possibly interval-censored data. The functionality of the package was considerably enhanced by implementing methods for Bayesian estimation of mixtures of multivariate generalized linear mixed models proposed in Komrek and Komrkov (2013. Among other things, this allows for a cluster analysis (classification based on multivariate continuous and discrete longitudinal data that arise whenever multiple outcomes of a different nature are recorded in a longitudinal study. This package also allows for a data-driven selection of a number of clusters as methods for selecting a number of mixture components were implemented. A model and clustering methodology for multivariate continuous and discrete longitudinal data is overviewed. Further, a step-by-step cluster analysis based jointly on three longitudinal variables of different types (continuous, count, dichotomous is given, which provides a user manual for using the package for similar problems.

  16. Make My Trip Count 2015

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — The Make My Trip Count (MMTC) commuter survey, conducted in September and October 2015 by GBA, the Pittsburgh 2030 District, and 10 other regional transportation...

  17. Direct calibration of click-counting detectors

    Science.gov (United States)

    Bohmann, M.; Kruse, R.; Sperling, J.; Silberhorn, C.; Vogel, W.

    2017-03-01

    We introduce and experimentally implement a method for the detector calibration of photon-number-resolving time-bin multiplexing layouts based on the measured click statistics of superconducting nanowire detectors. In particular, the quantum efficiencies, the dark count rates, and the positive operator-valued measures of these measurement schemes are directly obtained with high accuracy. The method is based on the moments of the click-counting statistics for coherent states with different coherent amplitudes. The strength of our analysis is that we can directly conclude—on a quantitative basis—that the detection strategy under study is well described by a linear response function for the light-matter interaction and that it is sensitive to the polarization of the incident light field. Moreover, our method is further extended to a two-mode detection scenario. Finally, we present possible applications for such well-characterized detectors, such as sensing of atmospheric loss channels and phase sensitive measurements.

  18. Mesoscopic full counting statistics and exclusion models

    Science.gov (United States)

    Roche, P.-E.; Derrida, B.; Douçot, B.

    2005-02-01

    We calculate the distribution of current fluctuations in two simple exclusion models. Although these models are classical, we recover even for small systems such as a simple or a double barrier, the same distibution of current as given by traditional formalisms for quantum mesoscopic conductors. Due to their simplicity, the full counting statistics in exclusion models can be reduced to the calculation of the largest eigenvalue of a matrix, the size of which is the number of internal configurations of the system. As examples, we derive the shot noise power and higher order statistics of current fluctuations (skewness, full counting statistics, ....) of various conductors, including multiple barriers, diffusive islands between tunnel barriers and diffusive media. A special attention is dedicated to the third cumulant, which experimental measurability has been demonstrated lately.

  19. Counting radon tracks in Makrofol detectors with the 'image reduction and analysis facility' (IRAF) software package

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez, F. [Laboratorio de Fisica Medica y Radioactividad Ambiental, Departamento de Medicina Fisica y Farmacologia, Universidad de La Laguna, 38320 La Laguna, Tenerife (Spain)]. E-mail: fimerall@ull.es; Gonzalez-Manrique, S. [Laboratorio de Fisica Medica y Radioactividad Ambiental, Departamento de Medicina Fisica y Farmacologia, Universidad de La Laguna, 38320 La Laguna, Tenerife (Spain); Karlsson, L. [Laboratorio de Fisica Medica y Radioactividad Ambiental, Departamento de Medicina Fisica y Farmacologia, Universidad de La Laguna, 38320 La Laguna, Tenerife (Spain); Hernandez-Armas, J. [Laboratorio de Fisica Medica y Radioactividad Ambiental, Departamento de Medicina Fisica y Farmacologia, Universidad de La Laguna, 38320 La Laguna, Tenerife (Spain); Aparicio, A. [Instituto de Astrofisica de Canarias, 38200 La Laguna, Tenerife (Spain); Departamento de Astrofisica, Universidad de La Laguna. Avenida. Astrofisico Francisco Sanchez s/n, 38071 La Laguna, Tenerife (Spain)

    2007-03-15

    Makrofol detectors are commonly used for long-term radon ({sup 222}Rn) measurements in houses, schools and workplaces. The use of this type of passive detectors for the determination of radon concentrations requires the counting of the nuclear tracks produced by alpha particles on the detecting material. The 'image reduction and analysis facility' (IRAF) software package is a piece of software commonly used in astronomical applications. It allows detailed counting and mapping of sky sections where stars are grouped very closely, even forming clusters. In order to count the nuclear tracks in our Makrofol radon detectors, we have developed an inter-disciplinary application that takes advantage of the similitude that exist between counting stars in a dark sky and tracks in a track-etch detector. Thus, a low cost semi-automatic system has been set up in our laboratory which utilises a commercially available desktop scanner and the IRAF software package. A detailed description of the proposed semi-automatic method and its performance, in comparison to ocular counting, is described in detail here. In addition, the calibration factor for this procedure, 2.97+/-0.07kBqm{sup -3}htrack{sup -1}cm{sup 2}, has been calculated based on the results obtained from exposing 46 detectors to certified radon concentrations. Furthermore, the results of a preliminary radon survey carried out in 62 schools in Tenerife island (Spain), using Makrofol detectors, counted with the mentioned procedure, are briefly presented. The results reported here indicate that the developed procedure permits a fast, accurate and unbiased determination of the radon tracks in a large number of detectors. The measurements carried out in the schools showed that the radon concentrations in at least 12 schools were above 200Bqm{sup -3} and, in two of them, above 400Bqm{sup -3}. Further studies should be performed at those schools following the European Union recommendations about radon concentrations in

  20. The Mayan Long Count Calendar

    OpenAIRE

    Chanier, Thomas

    2015-01-01

    The Maya were known for their astronomical proficiency. This is demonstrated in the Mayan codices where ritual practices were related to astronomical events/predictions. Whereas Mayan mathematics were based on a vigesimal system, they used a different base when dealing with long periods of time, the Long Count Calendar (LCC), composed of different Long Count Periods: the Tun of 360 days, the Katun of 7200 days and the Baktun of 144000 days. There were two other calendars used in addition to t...

  1. Counting Word Frequencies with Python

    Directory of Open Access Journals (Sweden)

    William J. Turkel

    2012-07-01

    Full Text Available Your list is now clean enough that you can begin analyzing its contents in meaningful ways. Counting the frequency of specific words in the list can provide illustrative data. Python has an easy way to count frequencies, but it requires the use of a new type of variable: the dictionary. Before you begin working with a dictionary, consider the processes used to calculate frequencies in a list.

  2. Design considerations for examining trends in avian abundance using point counts: examples from oak woodlands

    Science.gov (United States)

    Kathryn L. Purcell; Sylvia R. Mori; Mary K. Chase

    2005-01-01

    We used data from two oak-woodland sites in California to develop guidelines for the design of bird monitoring programs using point counts. We used power analysis to determine sample size adequacy when varying the number of visits, count stations, and years for examining trends in abundance. We assumed an overdispersed Poisson distribution for count data, with...

  3. Galaxy Counts at 24 Microns in the SWIRE Fields

    CERN Document Server

    Shupe, David L; Lonsdale, Carol J; Masci, Frank; Evans, Tracey; Fang, Fan; Oliver, Sebastian; Vaccari, Mattia; Rodighiero, Giulia; Padgett, Deborah; Surace, Jason A; Xu, C Kevin; Berta, Stefano; Pozzi, Francesca; Franceschini, Alberto; Babbedge, Thomas; Gonzales-Solares, Eduardo; Siana, Brian D; Farrah, Duncan; Frayer, David T; Smith, H E; Polletta, Maria; Owen, Frazer; Perez-Fournon, Ismael

    2007-01-01

    This paper presents galaxy source counts at 24 microns in the six Spitzer Wide-field InfraRed Extragalactic (SWIRE) fields. The source counts are compared to counts in other fields, and to model predictions that have been updated since the launch of Spitzer. This analysis confirms a very steep rise in the Euclidean-normalized differential number counts between 2 mJy and 0.3 mJy. Variations in the counts between fields show the effects of sample variance in the flux range 0.5-10 mJy, up to 100% larger than Poisson errors. Nonetheless, a "shoulder" in the normalized counts persists at around 3 mJy. The peak of the normalized counts at 0.3 mJy is higher and narrower than most models predict. In the ELAIS N1 field, the 24 micron data are combined with Spitzer-IRAC data and five-band optical imaging, and these bandmerged data are fit with photometric redshift templates. Above 1 mJy the counts are dominated by galaxies at z less than 0.3. By 300 microJy, about 25% are between z ~ 0.3-0.8, and a significant fraction...

  4. Three-Dimensional Computer-Aided Detection of Microcalcification Clusters in Digital Breast Tomosynthesis

    Directory of Open Access Journals (Sweden)

    Ji-wook Jeong

    2016-01-01

    Full Text Available We propose computer-aided detection (CADe algorithm for microcalcification (MC clusters in reconstructed digital breast tomosynthesis (DBT images. The algorithm consists of prescreening, MC detection, clustering, and false-positive (FP reduction steps. The DBT images containing the MC-like objects were enhanced by a multiscale Hessian-based three-dimensional (3D objectness response function and a connected-component segmentation method was applied to extract the cluster seed objects as potential clustering centers of MCs. Secondly, a signal-to-noise ratio (SNR enhanced image was also generated to detect the individual MC candidates and prescreen the MC-like objects. Each cluster seed candidate was prescreened by counting neighboring individual MC candidates nearby the cluster seed object according to several microcalcification clustering criteria. As a second step, we introduced bounding boxes for the accepted seed candidate, clustered all the overlapping cubes, and examined. After the FP reduction step, the average number of FPs per case was estimated to be 2.47 per DBT volume with a sensitivity of 83.3%.

  5. Meaningful Clusters

    Energy Technology Data Exchange (ETDEWEB)

    Sanfilippo, Antonio P.; Calapristi, Augustin J.; Crow, Vernon L.; Hetzler, Elizabeth G.; Turner, Alan E.

    2004-05-26

    We present an approach to the disambiguation of cluster labels that capitalizes on the notion of semantic similarity to assign WordNet senses to cluster labels. The approach provides interesting insights on how document clustering can provide the basis for developing a novel approach to word sense disambiguation.

  6. Making fingers and words count in a cognitive robot.

    Science.gov (United States)

    De La Cruz, Vivian M; Di Nuovo, Alessandro; Di Nuovo, Santo; Cangelosi, Angelo

    2014-01-01

    Evidence from developmental as well as neuroscientific studies suggest that finger counting activity plays an important role in the acquisition of numerical skills in children. It has been claimed that this skill helps in building motor-based representations of number that continue to influence number processing well into adulthood, facilitating the emergence of number concepts from sensorimotor experience through a bottom-up process. The act of counting also involves the acquisition and use of a verbal number system of which number words are the basic building blocks. Using a Cognitive Developmental Robotics paradigm we present results of a modeling experiment on whether finger counting and the association of number words (or tags) to fingers, could serve to bootstrap the representation of number in a cognitive robot, enabling it to perform basic numerical operations such as addition. The cognitive architecture of the robot is based on artificial neural networks, which enable the robot to learn both sensorimotor skills (finger counting) and linguistic skills (using number words). The results obtained in our experiments show that learning the number words in sequence along with finger configurations helps the fast building of the initial representation of number in the robot. Number knowledge, is instead, not as efficiently developed when number words are learned out of sequence without finger counting. Furthermore, the internal representations of the finger configurations themselves, developed by the robot as a result of the experiments, sustain the execution of basic arithmetic operations, something consistent with evidence coming from developmental research with children. The model and experiments demonstrate the importance of sensorimotor skill learning in robots for the acquisition of abstract knowledge such as numbers.

  7. Measuring the dark energy with quasar clustering

    CERN Document Server

    Calvão, M O; Waga, I

    2002-01-01

    We show, through Monte Carlo simulations, that the Alcock-Pazynski test, as applied to quasar clustering, is a powerful tool to probe the cosmological density and equation of state parameters, Omega_{m0}, Omega_{x0} and w. By taking into account peculiar velocity corrections to the correlation function we obtain, for the Two-Degree Field QSO Redshift Survey (2QZ), the predicted 1\\sigma and 2\\sigma confidence contours. It turns out that the test is competitive with future supernova and galaxy number count ones, besides being complementary to them, for fixed curvature. In particular, we find out that it is especially sensitive to the difference Omega_{m0}-Omega_{Lambda 0}, thus being ideal to combine with CMB results.

  8. Analysis of Decision Trees in Context Clustering of Hidden Markov Model Based Thai Speech Synthesis

    Directory of Open Access Journals (Sweden)

    Suphattharachai Chomphan

    2011-01-01

    Full Text Available Problem statement: In Thai speech synthesis using Hidden Markov model (HMM based synthesis system, the tonal speech quality is degraded due to tone distortion. This major problem must be treated appropriately to preserve the tone characteristics of each syllable unit. Since tone brings about the intelligibility of the synthesized speech. It is needed to establish the tone questions and other phonetic questions in tree-based context clustering process accordingly. Approach: This study describes the analysis of questions in tree-based context clustering process of an HMM-based speech synthesis system for Thai language. In the system, spectrum, pitch or F0 and state duration are modeled simultaneously in a unified framework of HMM, their parameter distributions are clustered independently by using a decision-tree based context clustering technique. The contextual factors which affect spectrum, pitch and duration, i.e., part of speech, position and number of phones in a syllable, position and number of syllables in a word, position and number of words in a sentence, phone type and tone type, are taken into account for constructing the questions of the decision tree. All in all, thirteen sets of questions are analyzed in comparison. Results: In the experiment, we analyzed the decision trees by counting the number of questions in each node coming from those thirteen sets and by calculating the dominance score given to each question as the reciprocal of the distance from the root node to the question node. The highest number and dominance score are of the set of phonetic type, while the second, third highest ones are of the set of part of speech and tone type. Conclusion: By counting the number of questions in each node and calculating the dominance score, we can set the priority of each question set. All in all, the analysis results bring about further development of Thai speech synthesis with efficient context clustering process in

  9. Multipixel silicon avalanche photodiode with ultralow dark count rate at liquid nitrogen temperature.

    Science.gov (United States)

    Akiba, M; Tsujino, K; Sato, K; Sasaki, M

    2009-09-14

    Multipixel silicon avalanche photodiodes (Si APDs) are novel photodetectors used as silicon photomultipliers (SiPMs), or multipixel photon counter (MPPC), because they have fast response, photon-number resolution, and a high count rate; one drawback, however, is the high dark count rate. We developed a system for cooling an MPPC to liquid nitrogen temperature and thus reduce the dark count rate. Our system achieved dark count rates of <0.2 cps. Here we present the afterpulse probability, counting capability, timing jitter, and photon-number resolution of our system at 78.5 K and 295 K.

  10. New Limits On Gamma-Ray Emission From Galaxy Clusters

    CERN Document Server

    Griffin, Rhiannon D; Kochanek, Christopher S

    2014-01-01

    Galaxy clusters are predicted to produce gamma-rays through cosmic ray interactions and/or dark matter annihilation, potentially detectable by the Fermi Large Area Telescope (Fermi-LAT). We present a new, independent stacking analysis of Fermi-LAT photon count maps using the 79 richest nearby clusters (z<0.12) from the Two Micron All-Sky Survey (2MASS) cluster catalog. We obtain the lowest limit on the photon flux to date, 1.1e-11 ph/s/cm^2 (95% confidence) per cluster in the 0.8--100~GeV band, which corresponds to a luminosity limit of 1.7e44 ph/s. We also constrain the emission limits in a range of narrower energy bands. Scaling to recent cosmic ray acceleration and gamma-ray emission models, we find that cosmic rays represent a negligible contribution to the intra-cluster energy density and gas pressure. Furthermore, either accretion shocks must have lower Mach numbers than usually assumed (2--4) or significantly less than 50% of the baryon mass has been processed through such shocks, and thus, the majo...

  11. Multiwavelength photometry in the Globular Cluster M2

    CERN Document Server

    Dalessandro, E; Lanzoni, B; Ferraro, F R; Schiavon, R; Rood, R T

    2009-01-01

    We present a multiwavelength photometric analysis of the globular cluster M2. The data-set has been obtained by combining high-resolution (HST/WFPC2 and ACS) and wide-field (GALEX) space observations and ground based (MEGACAM-CFHT, EMMI-NTT) images. The photometric sample covers the entire cluster extension from the very central regions up to the tidal radius and beyond. It allows an accurate determination of the cluster center of gravity and other structural parameters derived from the star count density profile. Moreover we study the BSS population and its radial distribution. A total of 123 BSS has been selected, and their radial distribution has been found to be bimodal (highly peaked in the center, decreasing at intermediate radii and rising outward), as already found in a number of other clusters. The radial position of the minimum of the BSS distribution is consistent with the radius of avoidance caused by the dynamical friction of massive objects over the cluster age. We also searched for gradients in...

  12. Microscopic images dataset for automation of RBCs counting

    Directory of Open Access Journals (Sweden)

    Sherif Abbas

    2015-12-01

    Full Text Available A method for Red Blood Corpuscles (RBCs counting has been developed using RBCs light microscopic images and Matlab algorithm. The Dataset consists of Red Blood Corpuscles (RBCs images and there RBCs segmented images. A detailed description using flow chart is given in order to show how to produce RBCs mask. The RBCs mask was used to count the number of RBCs in the blood smear image.

  13. Microscopic images dataset for automation of RBCs counting.

    Science.gov (United States)

    Abbas, Sherif

    2015-12-01

    A method for Red Blood Corpuscles (RBCs) counting has been developed using RBCs light microscopic images and Matlab algorithm. The Dataset consists of Red Blood Corpuscles (RBCs) images and there RBCs segmented images. A detailed description using flow chart is given in order to show how to produce RBCs mask. The RBCs mask was used to count the number of RBCs in the blood smear image.

  14. Hanford whole body counting manual

    Energy Technology Data Exchange (ETDEWEB)

    Palmer, H.E.; Rieksts, G.A.; Lynch, T.P.

    1990-06-01

    This document describes the Hanford Whole Body Counting Program as it is administered by Pacific Northwest Laboratory (PNL) in support of the US Department of Energy--Richland Operations Office (DOE-RL) and its Hanford contractors. Program services include providing in vivo measurements of internally deposited radioactivity in Hanford employees (or visitors). Specific chapters of this manual deal with the following subjects: program operational charter, authority, administration, and practices, including interpreting applicable DOE Orders, regulations, and guidance into criteria for in vivo measurement frequency, etc., for the plant-wide whole body counting services; state-of-the-art facilities and equipment used to provide the best in vivo measurement results possible for the approximately 11,000 measurements made annually; procedures for performing the various in vivo measurements at the Whole Body Counter (WBC) and related facilities including whole body counts; operation and maintenance of counting equipment, quality assurance provisions of the program, WBC data processing functions, statistical aspects of in vivo measurements, and whole body counting records and associated guidance documents. 16 refs., 48 figs., 22 tabs.

  15. Cluster Lenses

    CERN Document Server

    Kneib, Jean-Paul; 10.1007/s00159-011-0047-3

    2012-01-01

    Clusters of galaxies are the most recently assembled, massive, bound structures in the Universe. As predicted by General Relativity, given their masses, clusters strongly deform space-time in their vicinity. Clusters act as some of the most powerful gravitational lenses in the Universe. Light rays traversing through clusters from distant sources are hence deflected, and the resulting images of these distant objects therefore appear distorted and magnified. Lensing by clusters occurs in two regimes, each with unique observational signatures. The strong lensing regime is characterized by effects readily seen by eye, namely, the production of giant arcs, multiple-images, and arclets. The weak lensing regime is characterized by small deformations in the shapes of background galaxies only detectable statistically. Cluster lenses have been exploited successfully to address several important current questions in cosmology: (i) the study of the lens(es) - understanding cluster mass distributions and issues pertaining...

  16. Count data modeling and classification using finite mixtures of distributions.

    Science.gov (United States)

    Bouguila, Nizar

    2011-02-01

    In this paper, we consider the problem of constructing accurate and flexible statistical representations for count data, which we often confront in many areas such as data mining, computer vision, and information retrieval. In particular, we analyze and compare several generative approaches widely used for count data clustering, namely multinomial, multinomial Dirichlet, and multinomial generalized Dirichlet mixture models. Moreover, we propose a clustering approach via a mixture model based on a composition of the Liouville family of distributions, from which we select the Beta-Liouville distribution, and the multinomial. The novel proposed model, which we call multinomial Beta-Liouville mixture, is optimized by deterministic annealing expectation-maximization and minimum description length, and strives to achieve a high accuracy of count data clustering and model selection. An important feature of the multinomial Beta-Liouville mixture is that it has fewer parameters than the recently proposed multinomial generalized Dirichlet mixture. The performance evaluation is conducted through a set of extensive empirical experiments, which concern text and image texture modeling and classification and shape modeling, and highlights the merits of the proposed models and approaches.

  17. Antiretroviral therapy suppressed participants with low CD4+ T-cell counts segregate according to opposite immunological phenotypes

    Science.gov (United States)

    Pérez-Santiago, Josué; Ouchi, Dan; Urrea, Victor; Carrillo, Jorge; Cabrera, Cecilia; Villà-Freixa, Jordi; Puig, Jordi; Paredes, Roger; Negredo, Eugènia; Clotet, Bonaventura; Massanella, Marta; Blanco, Julià

    2016-01-01

    Background: The failure to increase CD4+ T-cell counts in some antiretroviral therapy suppressed participants (immunodiscordance) has been related to perturbed CD4+ T-cell homeostasis and impacts clinical evolution. Methods: We evaluated different definitions of immunodiscordance based on CD4+ T-cell counts (cutoff) or CD4+ T-cell increases from nadir value (ΔCD4) using supervised random forest classification of 74 immunological and clinical variables from 196 antiretroviral therapy suppressed individuals. Unsupervised clustering was performed using relevant variables identified in the supervised approach from 191 individuals. Results: Cutoff definition of CD4+ cell count 400 cells/μl performed better than any other definition in segregating immunoconcordant and immunodiscordant individuals (85% accuracy), using markers of activation, nadir and death of CD4+ T cells. Unsupervised clustering of relevant variables using this definition revealed large heterogeneity between immunodiscordant individuals and segregated participants into three distinct subgroups with distinct production, programmed cell-death protein-1 (PD-1) expression, activation and death of T cells. Surprisingly, a nonnegligible number of immunodiscordant participants (22%) showed high frequency of recent thymic emigrants and low CD4+ T-cell activation and death, very similar to immunoconcordant participants. Notably, human leukocyte antigen - antigen D related (HLA-DR) PD-1 and CD45RA expression in CD4+ T cells allowed reproducing subgroup segregation (81.4% accuracy). Despite sharp immunological differences, similar and persistently low CD4+ values were maintained in these participants over time. Conclusion: A cutoff value of CD4+ T-cell count 400 cells/μl classified better immunodiscordant and immunoconcordant individuals than any ΔCD4 classification. Immunodiscordance may present several, even opposite, immunological patterns that are identified by a simple immunological follow-up. Subgroup

  18. Introduction to cluster dynamics

    CERN Document Server

    Reinhard, Paul-Gerhard

    2008-01-01

    Clusters as mesoscopic particles represent an intermediate state of matter between single atoms and solid material. The tendency to miniaturise technical objects requires knowledge about systems which contain a ""small"" number of atoms or molecules only. This is all the more true for dynamical aspects, particularly in relation to the qick development of laser technology and femtosecond spectroscopy. Here, for the first time is a highly qualitative introduction to cluster physics. With its emphasis on cluster dynamics, this will be vital to everyone involved in this interdisciplinary subje

  19. Clustering Text Data Streams

    Institute of Scientific and Technical Information of China (English)

    Yu-Bao Liu; Jia-Rong Cai; Jian Yin; Ada Wai-Chee Fu

    2008-01-01

    Clustering text data streams is an important issue in data mining community and has a number of applications such as news group filtering, text crawling, document organization and topic detection and tracing etc. However, most methods are similarity-based approaches and only use the TF*IDF scheme to represent the semantics of text data and often lead to poor clustering quality. Recently, researchers argue that semantic smoothing model is more efficient than the existing TF.IDF scheme for improving text clustering quality. However, the existing semantic smoothing model is not suitable for dynamic text data context. In this paper, we extend the semantic smoothing model into text data streams context firstly. Based on the extended model, we then present two online clustering algorithms OCTS and OCTSM for the clustering of massive text data streams. In both algorithms, we also present a new cluster statistics structure named cluster profile which can capture the semantics of text data streams dynamically and at the same time speed up the clustering process. Some efficient implementations for our algorithms are also given. Finally, we present a series of experimental results illustrating the effectiveness of our technique.

  20. Language and counting: Some recent results

    Science.gov (United States)

    Bell, Garry

    1990-02-01

    It has long been recognised that the language of mathematics is an important variable in the learning of mathematics, and there has been useful work in isolating and describing the linkage. Steffe and his co-workers at Georgia, for example, (Steffe, von Glasersfeld, Richardson and Cobb, 1983) have suggested that young children may construct verbal countable items to count objects which are hidden from their view. Although there has been a surge of research interest in counting and early childhood mathematics, and in cultural differences in mathematics attainment, there has been little work reported on the linkage between culture as exemplified by language, and initial concepts of numeration. This paper reports on some recent clinical research with kindergarten children of European and Asian background in Australia and America. The research examines the influence that number naming grammar appears to have on young children's understandings of two-digit numbers and place value. It appears that Transparent Standard Number Word Sequences such as Japanese, Chinese and Vietnamese which follow the numerical representation pattern by naming tens and units in order ("two tens three"), may be associated with distinctive place value concepts which may support sophisticated mental algorithms.

  1. Strange Curves, Counting Rabbits, & Other Mathematical Explorations

    CERN Document Server

    Ball, Keith

    2011-01-01

    How does mathematics enable us to send pictures from space back to Earth? Where does the bell-shaped curve come from? Why do you need only 23 people in a room for a 50/50 chance of two of them sharing the same birthday? In Strange Curves, Counting Rabbits, and Other Mathematical Explorations, Keith Ball highlights how ideas, mostly from pure math, can answer these questions and many more. Drawing on areas of mathematics from probability theory, number theory, and geometry, he explores a wide range of concepts, some more light-hearted, others central to the development of the field and used dai

  2. Stellar populations in star clusters

    Science.gov (United States)

    Li, Cheng-Yuan; de Grijs, Richard; Deng, Li-Cai

    2016-12-01

    Stellar populations contain the most important information about star cluster formation and evolution. Until several decades ago, star clusters were believed to be ideal laboratories for studies of simple stellar populations (SSPs). However, discoveries of multiple stellar populations in Galactic globular clusters have expanded our view on stellar populations in star clusters. They have simultaneously generated a number of controversies, particularly as to whether young star clusters may have the same origin as old globular clusters. In addition, extensive studies have revealed that the SSP scenario does not seem to hold for some intermediate-age and young star clusters either, thus making the origin of multiple stellar populations in star clusters even more complicated. Stellar population anomalies in numerous star clusters are well-documented, implying that the notion of star clusters as true SSPs faces serious challenges. In this review, we focus on stellar populations in massive clusters with different ages. We present the history and progress of research in this active field, as well as some of the most recent improvements, including observational results and scenarios that have been proposed to explain the observations. Although our current ability to determine the origin of multiple stellar populations in star clusters is unsatisfactory, we propose a number of promising projects that may contribute to a significantly improved understanding of this subject.

  3. Radio observations of Planck clusters

    CERN Document Server

    Kale, Ruta

    2012-01-01

    Recently, a number of new galaxy clusters have been detected by the ESA-Planck satellite, the South Pole Telescope and the Atacama Cosmology Telescope using the Sunyaev-Zeldovich effect. Several of the newly detected clusters are massive, merging systems with disturbed morphology in the X-ray surface brightness. Diffuse radio sources in clusters, called giant radio halos and relics, are direct probes of cosmic rays and magnetic fields in the intra-cluster medium. These radio sources are found to occur mainly in massive merging clusters. Thus, the new SZ-discovered clusters are good candidates to search for new radio halos and relics. We have initiated radio observations of the clusters detected by Planck with the Giant Metrewave Radio Telescope. These observations have already led to the detection of a radio halo in PLCKG171.9-40.7, the first giant halo discovered in one of the new Planck clusters.

  4. An innovative method to reduce count loss from pulse pile-up in a photon-counting pixel for high flux X-ray applications

    Science.gov (United States)

    Lee, D.; Lim, K.; Park, K.; Lee, C.; Alexander, S.; Cho, G.

    2017-03-01

    In this study, an innovative fast X-ray photon-counting pixel for high X-ray flux applications is proposed. A computed tomography system typically uses X-ray fluxes up to 108 photons/mm2/sec at the detector and thus a fast read-out is required in order to process individual X-ray photons. Otherwise, pulse pile-up can occur at the output of the signal processing unit. These superimposed signals can distort the number of incident X-ray photons leading to count loss. To minimize such losses, a cross detection method was implemented in the photon-counting pixel. A maximum count rate under X-ray tube voltage of 90 kV was acquired which reflect electrical test results of the proposed photon counting pixel. A maximum count of 780 kcps was achieved with a conventional photon-counting pixel at the pulse processing time of 500 ns, which is the time for a pulse to return to the baseline from the initial rise. In contrast, the maximum count of about 8.1 Mcps was achieved with the proposed photon-counting pixel. From these results, it was clear that the maximum count rate was increased by approximately a factor 10 times by adopting the cross detection method. Therefore, it is an innovative method to reduce count loss from pulse pile-up in a photon-counting pixel while maintaining the pulse processing time.

  5. Statistics of clusters in binary linear lattices

    NARCIS (Netherlands)

    Felderhof, B.U.

    1972-01-01

    The statistics of clusters in binary linear lattices is studied on the assumption that the relative weight of an Al or Bm cluster is determined only by its size l or m, and is independent of the location of the cluster on the chain. The average cluster numbers and the variance of their fluctuations

  6. Estimating passenger numbers in trains using existing weighing capabilities

    DEFF Research Database (Denmark)

    Nielsen, Bo Friis; Frølich, Laura; Nielsen, Otto Anker

    2013-01-01

    in estimates of total numbers of passengers propagate along train runs. Counting errors in manual and electronic counting systems are typically flow-dependent, making uncertainty a function of volume. This paper presents a new counting technique that exploits the weighing systems installed in most modern...... trains to control braking. This technique makes passenger counting cheaper and ensures a complete sample. The paper compares numbers estimated by this technique with manual counts and counts from an infrared system in trains in urban Copenhagen. It shows that the weighing system provides more accurate...

  7. Cool Cluster Correctly Correlated

    Energy Technology Data Exchange (ETDEWEB)

    Varganov, Sergey Aleksandrovich [Iowa State Univ., Ames, IA (United States)

    2005-01-01

    to tens of atoms. Therefore, they are quantum objects. Some qualitative information about the geometries of such clusters can be obtained with classical empirical methods, for example geometry optimization using an empirical Lennard-Jones potential. However, to predict their accurate geometries and other physical and chemical properties it is necessary to solve a Schroedinger equation. If one is not interested in dynamics of clusters it is enough to solve the stationary (time-independent) Schroedinger equation (HΦ=EΦ). This equation represents a multidimensional eigenvalue problem. The solution of the Schroedinger equation is a set of eigenvectors (wave functions) and their eigenvalues (energies). The lowest energy solution (wave function) corresponds to the ground state of the cluster. The other solutions correspond to excited states. The wave function gives all information about the quantum state of the cluster and can be used to calculate different physical and chemical properties, such as photoelectron, X-ray, NMR, EPR spectra, dipole moment, polarizability etc. The dimensionality of the Schroedinger equation is determined by the number of particles (nuclei and electrons) in the cluster. The analytic solution is only known for a two particle problem. In order to solve the equation for clusters of interest it is necessary to make a number of approximations and use numerical methods.

  8. Repeatability of differential goat bulk milk culture and associations with somatic cell count, total bacterial count, and standard plate count

    OpenAIRE

    Koop, G.; Dik, N; Nielen, M; Lipman, L. J. A.

    2010-01-01

    The aims of this study were to assess how different bacterial groups in bulk milk are related to bulk milk somatic cell count (SCC), bulk milk total bacterial count (TBC), and bulk milk standard plate count (SPC) and to measure the repeatability of bulk milk culturing. On 53 Dutch dairy goat farms, 3 bulk milk samples were collected at intervals of 2 wk. The samples were cultured for SPC, coliform count, and staphylococcal count and for the presence of Staphylococcus aureus. Furthermore, SCC ...

  9. KIDS COUNT New Hampshire, 2000.

    Science.gov (United States)

    Shemitz, Elllen, Ed.

    This Kids Count report presents statewide trends in the well-being of New Hampshire's children. The statistical report is based on 22 indicators of child well-being in 5 interrelated areas: (1) children and families (including child population, births, children living with single parent, and children experiencing parental divorce); (2) economic…

  10. Counting a Culture of Mealworms

    Science.gov (United States)

    Ashbrook, Peggy

    2007-01-01

    Math is not the only topic that will be discussed when young children are asked to care for and count "mealworms," a type of insect larvae (just as caterpillars are the babies of butterflies, these larvae are babies of beetles). The following activity can take place over two months as the beetles undergo metamorphosis from larvae to adults. As the…

  11. Shakespeare Live! and Character Counts.

    Science.gov (United States)

    Brookshire, Cathy A.

    This paper discusses a live production of Shakespeare's "Macbeth" (in full costume but with no sets) for all public middle school and high school students in Harrisonburg and Rockingham, Virginia. The paper states that the "Character Counts" issues that are covered in the play are: decision making, responsibility and…

  12. Counting a Culture of Mealworms

    Science.gov (United States)

    Ashbrook, Peggy

    2007-01-01

    Math is not the only topic that will be discussed when young children are asked to care for and count "mealworms," a type of insect larvae (just as caterpillars are the babies of butterflies, these larvae are babies of beetles). The following activity can take place over two months as the beetles undergo metamorphosis from larvae to adults. As the…

  13. Organising Atoms, Clusters and Proteins on Surfaces

    Science.gov (United States)

    Palmer, Richard E.

    2008-10-01

    This talk will discuss new developments in the creation of nanoscale surface features and their applications in biomedicine. Electron-surface interactions and plasma methods play a crucial role in both the production and analysis of these ``atomic architectures.'' At the extreme limit, electron injection from the tip of a scanning tunnelling microscope (STM) enables bond-selective manipulation of individual polyatomic molecules [1]. On a more practical level, the controlled deposition of size-selected clusters [2], generated by magnetron sputtering and gas condensation followed by mass selection, represents a surprisingly efficient route to the fabrication of surface features of size 1-10 nm, the size scale of biological molecules such as proteins. STM and AFM measurements show the clusters can act as binding sites for individual protein molecules. For example, the pinning of size-selected AuN clusters (N = 1--2000) to the (hydrophobic) graphite surface presents bindings site for sulphur atoms and thus for the cysteine residues in protein molecules. Systematic studies of different proteins [3] provide ``ground rules'' for residue-specific protein immobilisation by clusters and have led to the development of a novel biochip for protein screening by a spin-off company. The 3D atomic structure of the clusters is highly relevant to such applications. We show that measurement of the scattered electron beam intensity - specifically, the high angle annular dark field (HAADF) signal - in the scanning transmission electron microscope (STEM) allows us (a) to count the number of atoms in a cluster on the surface and (b) to determine a 3D atom-density map of the cluster when an aberration-corrected STEM is used [4]. 1. P.A. Sloan and R.E. Palmer, Nature 434 367 (2005). 2. S. Pratontep, P. Preece, C. Xirouchaki, R.E. Palmer, C.F. Sanz-Navarro, S.D. Kenny and R. Smith, Phys. Rev. Lett. 90 055503 (2003). 3. R.E. Palmer, S. Pratontep and H.-G. Boyen, Nature Materials 2 443 (2003

  14. Cluster Chemistry

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    @@ Cansisting of eight scientists from the State Key Laboratory of Physical Chemistry of Solid Surfaces and Xiamen University, this creative research group is devoted to the research of cluster chemistry and creation of nanomaterials.After three-year hard work, the group scored a series of encouraging progresses in synthesis of clusters with special structures, including novel fullerenes, fullerene-like metal cluster compounds as well as other related nanomaterials, and their properties study.

  15. Cosmic numbers the numbers that define our universe

    CERN Document Server

    Stein, James D

    2011-01-01

    Our fascination with numbers begins when we are children and continues throughout our lives. We start counting our fingers and toes and end up balancing checkbooks and calculating risk. So powerful is the appeal of numbers that many people ascribe to them a mystical significance. Other numbers go beyond the supernatural, working to explain our universe and how it behaves. In Cosmic Numbers , mathematics professor James D. Stein traces the discovery, evolution, and interrelationships of the numbers that define our world. Everyone knows about the speed of light and absolute zero, but numbers lik

  16. Teaching Emotionally Disturbed Students to Count Feelings.

    Science.gov (United States)

    Bartels, Cynthia S.; Calkin, Abigail B.

    The paper describes a program to teach high school students with emotional and behavior problems to count their feelings, thereby improving their self concept. To aid in instruction, a hierarchy was developed which involved four phases: counting tasks completed and tasks not completed, counting independent actions in class, counting perceptions of…

  17. Can the presence of erupting or exfoliating teeth increase the salivary lactobacillus count?

    Science.gov (United States)

    Wikner, S; Moum, I

    1987-04-01

    The salivary lactobacillus count was assessed during school attendance among 1734 7-15-yr-old children and related to the number of teeth erupting within each age group. The prevalence of extremely low lactobacillus counts (less than or equal to 10(3)) was inversely correlated with the number of erupting teeth (P less than 0.001) but the differences were small. High counts differed only by 7% between ages with the lowest and the highest mean number of erupting or exfoliating teeth tend to elevate the lactobacillus count in individuals. On a population level the effect is small.

  18. Counts and Colours of Faint Stars in 5 Fields Near the North Galactic Pole

    OpenAIRE

    Infante, L.

    1994-01-01

    Faint star number counts in the photographic \\jmag band and \\bvcol colour distributions are presented for a 1.08 deg$^2$ field near the North Galactic Pole. Due to the excellent star/galaxy discrimination we count stars as faint as \\jmag = 23. We compare the number counts and colour distributions in 5 adjacent fields near SA57. The number counts and colour distributions are in very good agreement with previous data. However, we find that the large field-to-field scatter in the colour distribu...

  19. A Comparison of Galaxy Counting Techniques in Spectroscopically Undersampled Regions

    Science.gov (United States)

    Specian, Mike A.; Szalay, Alex S.

    2016-11-01

    Accurate measures of galactic overdensities are invaluable for precision cosmology. Obtaining these measurements is complicated when members of one’s galaxy sample lack radial depths, most commonly derived via spectroscopic redshifts. In this paper, we utilize the Sloan Digital Sky Survey’s Main Galaxy Sample to compare seven methods of counting galaxies in cells when many of those galaxies lack redshifts. These methods fall into three categories: assigning galaxies discrete redshifts, scaling the numbers counted using regions’ spectroscopic completeness properties, and employing probabilistic techniques. We split spectroscopically undersampled regions into three types—those inside the spectroscopic footprint, those outside but adjacent to it, and those distant from it. Through Monte Carlo simulations, we demonstrate that the preferred counting techniques are a function of region type, cell size, and redshift. We conclude by reporting optimal counting strategies under a variety of conditions.

  20. How to Learn the Natural Numbers: Inductive Inference and the Acquisition of Number Concepts

    Science.gov (United States)

    Margolis, Eric; Laurence, Stephen

    2008-01-01

    Theories of number concepts often suppose that the natural numbers are acquired as children learn to count and as they draw an induction based on their interpretation of the first few count words. In a bold critique of this general approach, Rips, Asmuth, Bloomfield [Rips, L., Asmuth, J. & Bloomfield, A. (2006). Giving the boot to the bootstrap:…

  1. Clustered mixed nonhomogeneous Poisson process spline models for the analysis of recurrent event panel data.

    Science.gov (United States)

    Nielsen, J D; Dean, C B

    2008-09-01

    A flexible semiparametric model for analyzing longitudinal panel count data arising from mixtures is presented. Panel count data refers here to count data on recurrent events collected as the number of events that have occurred within specific follow-up periods. The model assumes that the counts for each subject are generated by mixtures of nonhomogeneous Poisson processes with smooth intensity functions modeled with penalized splines. Time-dependent covariate effects are also incorporated into the process intensity using splines. Discrete mixtures of these nonhomogeneous Poisson process spline models extract functional information from underlying clusters representing hidden subpopulations. The motivating application is an experiment to test the effectiveness of pheromones in disrupting the mating pattern of the cherry bark tortrix moth. Mature moths arise from hidden, but distinct, subpopulations and monitoring the subpopulation responses was of interest. Within-cluster random effects are used to account for correlation structures and heterogeneity common to this type of data. An estimating equation approach to inference requiring only low moment assumptions is developed and the finite sample properties of the proposed estimating functions are investigated empirically by simulation.

  2. Testing circumstellar disk lifetimes in young embedded clusters associated with the Vela Molecular Ridge

    CERN Document Server

    Massi, Fabrizio; Codella, Claudio; Testi, Leonardo; Vanzi, Leonardo; Gomes, Joana

    2010-01-01

    Context. The Vela Molecular Ridge hosts a number of young embedded star clusters in the same evolutionary stage. Aims. The main aim of the present work is testing whether the fraction of members with a circumstellar disk in a sample of clusters in the cloud D of the Vela Molecular Ridge, is consistent with relations derived for larger samples of star clusters with an age spread. Besides, we want to constrain the age of the young embedded star clusters associated with cloud D. Methods. We carried out L (3.78 microns) photometry on images of six young embedded star clusters associated with cloud D of the Vela Molecular Ridge, taken with ISAAC at the VLT. These data are complemented with the available HKs photometry. The 6 clusters are roughly of the same size and appear to be in the same evolutionary stage. The fraction of stars with a circumstellar disk was measured in each cluster by counting the fraction of sources displaying a NIR excess in colour-colour (HKsL) diagrams. Results. The L photometry allowed us...

  3. Clustering via Kernel Decomposition

    DEFF Research Database (Denmark)

    Have, Anna Szynkowiak; Girolami, Mark A.; Larsen, Jan

    2006-01-01

    Methods for spectral clustering have been proposed recently which rely on the eigenvalue decomposition of an affinity matrix. In this work it is proposed that the affinity matrix is created based on the elements of a non-parametric density estimator. This matrix is then decomposed to obtain...... posterior probabilities of class membership using an appropriate form of nonnegative matrix factorization. The troublesome selection of hyperparameters such as kernel width and number of clusters can be obtained using standard cross-validation methods as is demonstrated on a number of diverse data sets....

  4. Clustering high dimensional data

    DEFF Research Database (Denmark)

    Assent, Ira

    2012-01-01

    High-dimensional data, i.e., data described by a large number of attributes, pose specific challenges to clustering. The so-called ‘curse of dimensionality’, coined originally to describe the general increase in complexity of various computational problems as dimensionality increases, is known...... to render traditional clustering algorithms ineffective. The curse of dimensionality, among other effects, means that with increasing number of dimensions, a loss of meaningful differentiation between similar and dissimilar objects is observed. As high-dimensional objects appear almost alike, new approaches...

  5. Predictive Model Assessment for Count Data

    Science.gov (United States)

    2007-09-05

    critique count regression models for patent data, and assess the predictive performance of Bayesian age-period-cohort models for larynx cancer counts...the predictive performance of Bayesian age-period-cohort models for larynx cancer counts in Germany. We consider a recent suggestion by Baker and...Figure 5. Boxplots for various scores for patent data count regressions. 11 Table 1 Four predictive models for larynx cancer counts in Germany, 1998–2002

  6. Clustered regression with unknown clusters

    CERN Document Server

    Barman, Kishor

    2011-01-01

    We consider a collection of prediction experiments, which are clustered in the sense that groups of experiments ex- hibit similar relationship between the predictor and response variables. The experiment clusters as well as the regres- sion relationships are unknown. The regression relation- ships define the experiment clusters, and in general, the predictor and response variables may not exhibit any clus- tering. We call this prediction problem clustered regres- sion with unknown clusters (CRUC) and in this paper we focus on linear regression. We study and compare several methods for CRUC, demonstrate their applicability to the Yahoo Learning-to-rank Challenge (YLRC) dataset, and in- vestigate an associated mathematical model. CRUC is at the crossroads of many prior works and we study several prediction algorithms with diverse origins: an adaptation of the expectation-maximization algorithm, an approach in- spired by K-means clustering, the singular value threshold- ing approach to matrix rank minimization u...

  7. Scalable Density-Based Subspace Clustering

    DEFF Research Database (Denmark)

    Müller, Emmanuel; Assent, Ira; Günnemann, Stephan;

    2011-01-01

    For knowledge discovery in high dimensional databases, subspace clustering detects clusters in arbitrary subspace projections. Scalability is a crucial issue, as the number of possible projections is exponential in the number of dimensions. We propose a scalable density-based subspace clustering ...

  8. Preset time count rate meter using adaptive digital signal processing

    Directory of Open Access Journals (Sweden)

    Žigić Aleksandar D.

    2005-01-01

    Full Text Available Two presented methods were developed to improve classical preset time count rate meters by using adapt able signal processing tools. An optimized detection algorithm that senses the change of mean count rate was implemented in both methods. Three low-pass filters of various structures with adaptable parameters to implement the control of the mean count rate error by suppressing the fluctuations in a controllable way, were considered and one of them implemented in both methods. An adaptation algorithm for preset time interval calculation executed after the low-pass filter was devised and implemented in the first method. This adaptation algorithm makes it possible to obtain shorter preset time intervals for higher stationary mean count rate. The adaptation algorithm for preset time interval calculation executed before the low-pass filter was devised and implemented in the second method. That adaptation algorithm enables sensing of a rapid change of the mean count rate before fluctuations suppression is carried out. Some parameters were fixed to their optimum values after appropriate optimization procedure. Low-pass filters have variable number of stationary coefficients depending on the specified error and the mean count rate. They implement control of the mean count rate error by suppressing fluctuations in a controllable way. The simulated and realized methods, using the developed algorithms, guarantee that the response time shall not exceed 2 s for the mean count rate higher than 2 s-1 and that controllable mean count rate error shall be within the range of ±4% to ±10%.

  9. Counting surfaces CRM Aisenstadt chair lectures

    CERN Document Server

    Eynard, Bertrand

    2016-01-01

    The problem of enumerating maps (a map is a set of polygonal "countries" on a world of a certain topology, not necessarily the plane or the sphere) is an important problem in mathematics and physics, and it has many applications ranging from statistical physics, geometry, particle physics, telecommunications, biology, ... etc. This problem has been studied by many communities of researchers, mostly combinatorists, probabilists, and physicists. Since 1978, physicists have invented a method called "matrix models" to address that problem, and many results have been obtained. Besides, another important problem in mathematics and physics (in particular string theory), is to count Riemann surfaces. Riemann surfaces of a given topology are parametrized by a finite number of real parameters (called moduli), and the moduli space is a finite dimensional compact manifold or orbifold of complicated topology. The number of Riemann surfaces is the volume of that moduli space. More generally, an important problem in algeb...

  10. Electrostatically defined silicon quantum dots with counted antimony donor implants

    Energy Technology Data Exchange (ETDEWEB)

    Singh, M., E-mail: msingh@sandia.gov; Luhman, D. R.; Lilly, M. P. [Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States); Center for Integrated Nanotechnologies, Sandia National Laboratories, Albuquerque, New Mexico 87175 (United States); Pacheco, J. L.; Perry, D.; Garratt, E.; Ten Eyck, G.; Bishop, N. C.; Wendt, J. R.; Manginell, R. P.; Dominguez, J.; Pluym, T.; Bielejec, E.; Carroll, M. S. [Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States)

    2016-02-08

    Deterministic control over the location and number of donors is crucial to donor spin quantum bits (qubits) in semiconductor based quantum computing. In this work, a focused ion beam is used to implant antimony donors in 100 nm × 150 nm windows straddling quantum dots. Ion detectors are integrated next to the quantum dots to sense the implants. The numbers of donors implanted can be counted to a precision of a single ion. In low-temperature transport measurements, regular Coulomb blockade is observed from the quantum dots. Charge offsets indicative of donor ionization are also observed in devices with counted donor implants.

  11. Counting publications and citations: Is more always better?

    CERN Document Server

    Waltman, Ludo; Wouters, Paul

    2013-01-01

    Is more always better? We address this question in the context of bibliometric indices that aim to assess the scientific impact of individual researchers by counting their number of highly cited publications. We propose a simple model in which the number of citations of a publication depends not only on the scientific impact of the publication but also on other 'random' factors. Our model indicates that more need not always be better. It turns out that the most influential researchers may have a systematically lower performance, in terms of highly cited publications, than some of their less influential colleagues. The model also suggests an improved way of counting highly cited publications.

  12. Cluster headache

    Directory of Open Access Journals (Sweden)

    Ducros Anne

    2008-07-01

    Full Text Available Abstract Cluster headache (CH is a primary headache disease characterized by recurrent short-lasting attacks (15 to 180 minutes of excruciating unilateral periorbital pain accompanied by ipsilateral autonomic signs (lacrimation, nasal congestion, ptosis, miosis, lid edema, redness of the eye. It affects young adults, predominantly males. Prevalence is estimated at 0.5–1.0/1,000. CH has a circannual and circadian periodicity, attacks being clustered (hence the name in bouts that can occur during specific months of the year. Alcohol is the only dietary trigger of CH, strong odors (mainly solvents and cigarette smoke and napping may also trigger CH attacks. During bouts, attacks may happen at precise hours, especially during the night. During the attacks, patients tend to be restless. CH may be episodic or chronic, depending on the presence of remission periods. CH is associated with trigeminovascular activation and neuroendocrine and vegetative disturbances, however, the precise cautive mechanisms remain unknown. Involvement of the hypothalamus (a structure regulating endocrine function and sleep-wake rhythms has been confirmed, explaining, at least in part, the cyclic aspects of CH. The disease is familial in about 10% of cases. Genetic factors play a role in CH susceptibility, and a causative role has been suggested for the hypocretin receptor gene. Diagnosis is clinical. Differential diagnoses include other primary headache diseases such as migraine, paroxysmal hemicrania and SUNCT syndrome. At present, there is no curative treatment. There are efficient treatments to shorten the painful attacks (acute treatments and to reduce the number of daily attacks (prophylactic treatments. Acute treatment is based on subcutaneous administration of sumatriptan and high-flow oxygen. Verapamil, lithium, methysergide, prednisone, greater occipital nerve blocks and topiramate may be used for prophylaxis. In refractory cases, deep-brain stimulation of the

  13. Subspace clustering through attribute clustering

    Institute of Scientific and Technical Information of China (English)

    Kun NIU; Shubo ZHANG; Junliang CHEN

    2008-01-01

    Many recently proposed subspace clustering methods suffer from two severe problems. First, the algorithms typically scale exponentially with the data dimensionality or the subspace dimensionality of clusters. Second, the clustering results are often sensitive to input parameters. In this paper, a fast algorithm of subspace clustering using attribute clustering is proposed to over-come these limitations. This algorithm first filters out redundant attributes by computing the Gini coefficient. To evaluate the correlation of every two non-redundant attributes, the relation matrix of non-redundant attributes is constructed based on the relation function of two dimensional united Gini coefficients. After applying an overlapping clustering algorithm on the relation matrix, the candidate of all interesting subspaces is achieved. Finally, all subspace clusters can be derived by clustering on interesting subspaces. Experiments on both synthesis and real datasets show that the new algorithm not only achieves a significant gain of runtime and quality to find subspace clusters, but also is insensitive to input parameters.

  14. The Prevalence and Disadvantage of Min-Counting in Seventh Grade: Problems with Confidence as Well as Accuracy?

    Science.gov (United States)

    Hopkins, Sarah; Bayliss, Donna

    2017-01-01

    In this research, we examined how 200 students in seventh grade (around 12 years old) solved simple addition problems. A cluster approach revealed that less than half of the cohort displayed proficiency with simple addition: 35% predominantly used min-counting and were accurate, and 16% frequently made min-counting errors. Students who frequently…

  15. The Prevalence and Disadvantage of Min-Counting in Seventh Grade: Problems with Confidence as Well as Accuracy?

    Science.gov (United States)

    Hopkins, Sarah; Bayliss, Donna

    2017-01-01

    In this research, we examined how 200 students in seventh grade (around 12 years old) solved simple addition problems. A cluster approach revealed that less than half of the cohort displayed proficiency with simple addition: 35% predominantly used min-counting and were accurate, and 16% frequently made min-counting errors. Students who frequently…

  16. Clustering behavior of hermit crabs (Decapoda, Anomura) in an intertidal rocky shore at São Sebastião, southeastern Brazil.

    Science.gov (United States)

    Turra, A; Leite, F P

    2000-02-01

    The clustering behavior and cluster composition of hermit crabs as well as the patterns of shell utilization of clustered and scattered individuals were studied. This study was conducted in the intertidal region of Grande Beach, São Sebastião, southeastern Brazil. Samples were taken both in randomized transects and 1 m2 quadrats during low tide periods. Crabs were counted, measured (shield length), and sexed. Shells were identified and had their adequacy and condition (physical damage and incrustation) recorded. Clusters occurred mainly in air exposed areas and were dominated or composed only by Clibanarius antillensis. Other species like Paguristes tortugae, Pagurus criniticornis, and Calcinus tibicen were also present in these clusters, but in small numbers. Only one monospecific aggregation composed by individuals of P. criniticornis was recorded in tide pools. Almost all crabs were inactive, despite some that were submerged in tide pools. Most of the individuals of C. antillensis were clustered (70.88%). Scattered individuals were larger than clustered ones and occupied mainly shells of Tegula viridula, which seemed to be the most adequate shell to the crabs. Clustered individuals used less incrusted shells than isolated ones. In general, clustering in Grande Beach presented the same patterns of size and sex distribution, and shell utilization than others already studied, with the exception of the smaller cluster size registered in this area.

  17. New constraints on $f(R)$ gravity from clusters of galaxies

    CERN Document Server

    Cataneo, Matteo; Schmidt, Fabian; Mantz, Adam B; Allen, Steven W; Applegate, Douglas E; Kelly, Patrick L; von der Linden, Anja; Morris, R Glenn

    2014-01-01

    The abundance of massive galaxy clusters is a powerful probe of departures from General Relativity (GR) on cosmic scales. Despite current stringent constraints placed by stellar and galactic tests, on larger scales alternative theories of gravity such as $f(R)$ can still work as effective theories. Here we present constraints on two popular models of $f(R)$, Hu-Sawicki and "designer", derived from a fully self-consistent analysis of current samples of X-ray selected clusters and accounting for all the covariances between cosmological and astrophysical parameters. Our constraints are mainly driven by cluster number counts, and we obtain substantial improvements on previous upper bounds employing this method. We also combine these results with recent data from the cosmic microwave background (CMB) and the CMB lensing potential generated by large scale structures, as well as with other cosmological constraints on the background expansion history and its mean matter density. The robustness of our results derives ...

  18. The Effects of Relativistic Corrections on Cosmological Parameter Estimations from SZE Cluster Surveys

    CERN Document Server

    Fan, Z H

    2003-01-01

    Sunyaev-Zel'dovich Effect (SZE) cluster surveys are anticipated to yield tight constraints on cosmological parameters such as the equation of state of dark energy. In this paper, we study the impact of relativistic corrections of the thermal SZE on the cluster number counts expected from a cosmological model and thus, assuming that other cosmological parameters are known to high accuracies, on the determination of the $w$ parameter and $\\sigma_8$ from a SZE cluster survey, where $w=p/\\rho$ with $p$ the pressure and $\\rho$ the density of dark energy, and $\\sigma_8$ is the rms of the extrapolated linear density fluctuation smoothed over $8\\hbox{Mpc}h^{-1}$. For the purpose of illustrating the effects of relativistic corrections, our analyses mainly focus on $\

  19. The Complexity of Approximately Counting Stable Roommate Assignments

    CERN Document Server

    Chebolu, Prasad; Martin, Russell

    2010-01-01

    We investigate the complexity of approximately counting stable roommate assignments in two models: (i) the $k$-attribute model, in which the preference lists are determined by dot products of "preference vectors" with "attribute vectors" and (ii) the $k$-Euclidean model, in which the preference lists are determined by the closeness of the "positions" of the people to their "preferred positions". Exactly counting the number of assignments is #P-complete, since Irving and Leather demonstrated #P-completeness for the special case of the stable marriage problem. We show that counting the number of stable roommate assignments in the $k$-attribute model ($k \\geq 4$) and the $3$-Euclidean model($k \\geq 3$) is interreducible, in an approximation-preserving sense, with counting independent sets (of all sizes) (#IS) in a graph, or counting the number of satisfying assignments of a Boolean formula (#SAT). This means that there can be no FPRAS for any of these problems unless NP=RP. As a consequence, we infer that there ...

  20. Constraining neutrino properties with a Euclid-like galaxy cluster survey

    CERN Document Server

    Cerbolini, M Costanzi Alunno; Xia, Jun-Qing; Biviano, A; Borgani, S; Viel, M

    2013-01-01

    We perform a forecast analysis on how well a Euclid-like photometric galaxy cluster survey will constrain the total neutrino mass and effective number of neutrino species. We base our analysis on the Monte Carlo Markov Chains technique by combining information from cluster number counts and cluster power spectrum. We find that combining cluster data with CMB measurements from Planck improves by more than an order of magnitude the constraint on neutrino masses compared to each probe used independently. For the LCDM+m_nu model the 2 sigma upper limit on total neutrino mass shifts from M_nu < 0.35 eV using cluster data alone to M_nu < 0.031 eV when combined with CMB data. When a non-standard model with N_eff number of neutrino species is considered, we estimate N_eff<3.14 (95% CL), while the bounds on neutrino mass are relaxed to M_nu < 0.040 eV. This accuracy would be sufficient for a 2 sigma detection of neutrino mass even in the minimal normal hierarchy scenario. We also consider scenarios with a ...

  1. The Mayan Long Count Calendar

    CERN Document Server

    Chanier, Thomas

    2013-01-01

    The Maya had a very elaborate and accurate calendar. First, the Mayan Long Count Calendar (LCC) was used to point historical events from a selected "beginning of time". It is also characterized by the existence of a religious month Tzolk'in of 260 days and a civic year Haab' of 365 days. The LCC is supposed to begin on 11 August -3114 BC known as the Goodman-Martinez-Thompson (GMT) correlation to the Gregorian calendar based on historical facts and end on 21 December 2012 corresponding to a period of approximately 5125 years or 13 Baktun. We propose here to explain the origin the 13 Baktun cycle, the Long Count Periods and the religious month Tzolk'in.

  2. Counting Irreducible Double Occurrence Words

    CERN Document Server

    Burns, Jonathan

    2011-01-01

    A double occurrence word $w$ over a finite alphabet $\\Sigma$ is a word in which each alphabet letter appears exactly twice. Such words arise naturally in the study of topology, graph theory, and combinatorics. Recently, double occurrence words have been used for studying DNA recombination events. We develop formulas for counting and enumerating several elementary classes of double occurrence words such as palindromic, irreducible, and strongly-irreducible words.

  3. Monitoring Milk Somatic Cell Counts

    Directory of Open Access Journals (Sweden)

    Gheorghe Şteţca

    2014-11-01

    Full Text Available The presence of somatic cells in milk is a widely disputed issue in milk production sector. The somatic cell counts in raw milk are a marker for the specific cow diseases such as mastitis or swollen udder. The high level of somatic cells causes physical and chemical changes to milk composition and nutritional value, and as well to milk products. Also, the mastitic milk is not proper for human consumption due to its contribution to spreading of certain diseases and food poisoning. According to these effects, EU Regulations established the maximum threshold of admitted somatic cells in raw milk to 400000 cells / mL starting with 2014. The purpose of this study was carried out in order to examine the raw milk samples provided from small farms, industrial type farms and milk processing units. There are several ways to count somatic cells in milk but the reference accepted method is the microscopic method described by the SR EN ISO 13366-1/2008. Generally samples registered values in accordance with the admissible limit. By periodical monitoring of the somatic cell count, certain technological process issues are being avoided and consumer’s health ensured.

  4. Manual and automated reticulocyte counts.

    Science.gov (United States)

    Simionatto, Mackelly; de Paula, Josiane Padilha; Chaves, Michele Ana Flores; Bortoloso, Márcia; Cicchetti, Domenic; Leonart, Maria Suely Soares; do Nascimento, Aguinaldo José

    2010-12-01

    Manual reticulocyte counts were examined under light microscopy, using the property whereby supravital stain precipitates residual ribosomal RNA versus the automated flow methods, with the suggestion that in the latter there is greater precision and an ability to determine both mature and immature reticulocyte fractions. Three hundred and forty-one venous blood samples of patients were analyzed of whom 224 newborn and the rest adults; 51 males and 66 females, with ages between 0 and 89 years, as part of the laboratory routine for hematological examinations at the Clinical Laboratory of the Hospital Universitário do Oeste do Paraná. This work aimed to compare manual and automated methodologies for reticulocyte countings and evaluate random and systematic errors. The results obtained showed that the difference between the two methods was very small, with an estimated 0·4% systematic error and 3·9% random error. Thus, it has been confirmed that both methods, when well conducted, can reflect precisely the reticulocyte counts for adequate clinical use.

  5. Don't spin the pen: two alternative methods for second-stage sampling in urban cluster surveys

    Directory of Open Access Journals (Sweden)

    Rose Angela MC

    2007-06-01

    Full Text Available Abstract In two-stage cluster surveys, the traditional method used in second-stage sampling (in which the first household in a cluster is selected is time-consuming and may result in biased estimates of the indicator of interest. Firstly, a random direction from the center of the cluster is selected, usually by spinning a pen. The houses along that direction are then counted out to the boundary of the cluster, and one is then selected at random to be the first household surveyed. This process favors households towards the center of the cluster, but it could easily be improved. During a recent meningitis vaccination coverage survey in Maradi, Niger, we compared this method of first household selection to two alternatives in urban zones: 1 using a superimposed grid on the map of the cluster area and randomly selecting an intersection; and 2 drawing the perimeter of the cluster area using a Global Positioning System (GPS and randomly selecting one point within the perimeter. Although we only compared a limited number of clusters using each method, we found the sampling grid method to be the fastest and easiest for field survey teams, although it does require a map of the area. Selecting a random GPS point was also found to be a good method, once adequate training can be provided. Spinning the pen and counting households to the boundary was the most complicated and time-consuming. The two methods tested here represent simpler, quicker and potentially more robust alternatives to spinning the pen for cluster surveys in urban areas. However, in rural areas, these alternatives would favor initial household selection from lower density (or even potentially empty areas. Bearing in mind these limitations, as well as available resources and feasibility, investigators should choose the most appropriate method for their particular survey context.

  6. Sagan numbers

    OpenAIRE

    Mendonça, J. Ricardo G.

    2012-01-01

    We define a new class of numbers based on the first occurrence of certain patterns of zeros and ones in the expansion of irracional numbers in a given basis and call them Sagan numbers, since they were first mentioned, in a special case, by the North-american astronomer Carl E. Sagan in his science-fiction novel "Contact." Sagan numbers hold connections with a wealth of mathematical ideas. We describe some properties of the newly defined numbers and indicate directions for further amusement.

  7. Fibonacci numbers

    CERN Document Server

    Vorob'ev, Nikolai Nikolaevich

    2011-01-01

    Fibonacci numbers date back to an 800-year-old problem concerning the number of offspring born in a single year to a pair of rabbits. This book offers the solution and explores the occurrence of Fibonacci numbers in number theory, continued fractions, and geometry. A discussion of the ""golden section"" rectangle, in which the lengths of the sides can be expressed as a ration of two successive Fibonacci numbers, draws upon attempts by ancient and medieval thinkers to base aesthetic and philosophical principles on the beauty of these figures. Recreational readers as well as students and teacher

  8. On the assessment of the nature of open star clusters and the determination of their basic parameters with limited data

    Science.gov (United States)

    Carraro, Giovanni; Baume, Gustavo; Seleznev, Anton F.; Costa, Edgardo

    2017-07-01

    Our knowledge of stellar evolution and of the structure and chemical evolution of the Galactic disk largely builds on the study of open star clusters. Because of their crucial role in these relevant topics, large homogeneous catalogues of open cluster parameters are highly desirable. Although efforts have been made to develop automatic tools to analyse large numbers of clusters, the results obtained so far vary from study to study, and sometimes are very contradictory when compared to dedicated studies of individual clusters. In this work we highlight the common causes of these discrepancies for some open clusters, and show that at present dedicated studies yield a much better assessment of the nature of star clusters, even in the absence of ideal data-sets. We make use of deep, wide-field, multi-colour photometry to discuss the nature of six strategically selected open star clusters: Trumpler 22, Lynga 6, Hogg 19, Hogg 21, Pismis 10 and Pismis 14. We have precisely derived their basic parameters by means of a combination of star counts and photometric diagrams. Trumpler 22 and Lynga 6 are included in our study because they are widely known, and thus provided a check of our data and methodology. The remaining four clusters are very poorly known, and their available parameters have been obtained using automatic tools only. Our results are in some cases in severe disagreement with those from automatic surveys.

  9. Number names and number understanding

    DEFF Research Database (Denmark)

    Ejersbo, Lisser Rye; Misfeldt, Morten

    2014-01-01

    through using mathematical names for the numbers such as one-ten-one for 11 and five-ten-six for 56. The project combines the renaming of numbers with supporting the teaching with the new number names. Our hypothesis is that Danish children have more difficulties learning and working with numbers, because...... the Danish number names are more complicated than in other languages. Keywords: A research project in grade 0 and 1th in a Danish school, Base-10 system, two-digit number names, semiotic, cognitive perspectives....

  10. Novel Cluster Validity Index for FCM Algorithm

    Institute of Scientific and Technical Information of China (English)

    Jian Yu; Cui-Xia Li

    2006-01-01

    How to determine an appropriate number of clusters is very important when implementing a specific clustering algorithm, like c-means, fuzzy c-means (FCM). In the literature, most cluster validity indices are originated from partition or geometrical property of the data set. In this paper, the authors developed a novel cluster validity index for FCM, based on the optimality test of FCM. Unlike the previous cluster validity indices, this novel cluster validity index is inherent in FCM itself. Comparison experiments show that the stability index can be used as cluster validity index for the fuzzy c-means.

  11. Weighted Clustering

    CERN Document Server

    Ackerman, Margareta; Branzei, Simina; Loker, David

    2011-01-01

    In this paper we investigate clustering in the weighted setting, in which every data point is assigned a real valued weight. We conduct a theoretical analysis on the influence of weighted data on standard clustering algorithms in each of the partitional and hierarchical settings, characterising the precise conditions under which such algorithms react to weights, and classifying clustering methods into three broad categories: weight-responsive, weight-considering, and weight-robust. Our analysis raises several interesting questions and can be directly mapped to the classical unweighted setting.

  12. Cluster analysis

    CERN Document Server

    Everitt, Brian S; Leese, Morven; Stahl, Daniel

    2011-01-01

    Cluster analysis comprises a range of methods for classifying multivariate data into subgroups. By organizing multivariate data into such subgroups, clustering can help reveal the characteristics of any structure or patterns present. These techniques have proven useful in a wide range of areas such as medicine, psychology, market research and bioinformatics.This fifth edition of the highly successful Cluster Analysis includes coverage of the latest developments in the field and a new chapter dealing with finite mixture models for structured data.Real life examples are used throughout to demons

  13. Effects of lek count protocols on greater sage-grouse population trend estimates

    Science.gov (United States)

    Monroe, Adrian; Edmunds, David; Aldridge, Cameron L.

    2016-01-01

    Annual counts of males displaying at lek sites are an important tool for monitoring greater sage-grouse populations (Centrocercus urophasianus), but seasonal and diurnal variation in lek attendance may increase variance and bias of trend analyses. Recommendations for protocols to reduce observation error have called for restricting lek counts to within 30 minutes of sunrise, but this may limit the number of lek counts available for analysis, particularly from years before monitoring was widely standardized. Reducing the temporal window for conducting lek counts also may constrain the ability of agencies to monitor leks efficiently. We used lek count data collected across Wyoming during 1995−2014 to investigate the effect of lek counts conducted between 30 minutes before and 30, 60, or 90 minutes after sunrise on population trend estimates. We also evaluated trends across scales relevant to management, including statewide, within Working Group Areas and Core Areas, and for individual leks. To further evaluate accuracy and precision of trend estimates from lek count protocols, we used simulations based on a lek attendance model and compared simulated and estimated values of annual rate of change in population size (λ) from scenarios of varying numbers of leks, lek count timing, and count frequency (counts/lek/year). We found that restricting analyses to counts conducted within 30 minutes of sunrise generally did not improve precision of population trend estimates, although differences among timings increased as the number of leks and count frequency decreased. Lek attendance declined >30 minutes after sunrise, but simulations indicated that including lek counts conducted up to 90 minutes after sunrise can increase the number of leks monitored compared to trend estimates based on counts conducted within 30 minutes of sunrise. This increase in leks monitored resulted in greater precision of estimates without reducing accuracy. Increasing count

  14. Are megaquakes clustered?

    CERN Document Server

    Daub, Eric G; Guyer, Robert A; Johnson, Paul A

    2012-01-01

    We study statistical properties of the number of large earthquakes over the past century. We analyze the cumulative distribution of the number of earthquakes with magnitude larger than threshold M in time interval T, and quantify the statistical significance of these results by simulating a large number of synthetic random catalogs. We find that in general, the earthquake record cannot be distinguished from a process that is random in time. This conclusion holds whether aftershocks are removed or not, except at magnitudes below M = 7.3. At long time intervals (T = 2-5 years), we find that statistically significant clustering is present in the catalog for lower magnitude thresholds (M = 7-7.2). However, this clustering is due to a large number of earthquakes on record in the early part of the 20th century, when magnitudes are less certain.

  15. RAPID REAL TIME PCR BASED DETECTION OF CELL COUNT IN CASE OF URINARY TRACT INFECTION

    Directory of Open Access Journals (Sweden)

    Poulomi Nandy

    2013-01-01

    Full Text Available Microbial identification and antimicrobial susceptibility testing methods currently used in clinical microbiology laboratories require at least two to three days because they rely on the growth and isolation of micro-organisms. This long, but necessary, delay has enormous consequences on prophylactic usage of antimicrobial drugs. This study was an attempt to reduce this detection time span. Taq Man Real Time PCR has been used as an important tool in the differentiation of Gram nature of bacteria present in UTI patients that allows detection of spiked bacterial 16S rDNA from urine samples within a short span of 5h and also gives us the corresponding cell count of both/either Gram positive and negative organisms present. A standard curve was generated which was used to determine the cell count of control as well as patient samples. Detection could be done in the range of 103 to 106 cells/mL Patient samples screened clustered either in the allele 1 or allele 2 axes, depending on majority concentration of Gram nature of the micro-organisms. The cell counts for control individuals were scattered within 0 to 102, while very few in the range of 104. The case was just reverse for patient group, where most of the points were scattered within 104 to 108. Thus the optimal selection of appropriate antimicrobials (depending on the gram nature by clinicians, will be gradually improved as an increasing number of rapid molecular diagnostic tools for the detection, identification and characterization of infectious agents become commercially available.

  16. Extended Fuzzy Clustering Algorithms

    NARCIS (Netherlands)

    U. Kaymak (Uzay); M. Setnes

    2000-01-01

    textabstractFuzzy clustering is a widely applied method for obtaining fuzzy models from data. It has been applied successfully in various fields including finance and marketing. Despite the successful applications, there are a number of issues that must be dealt with in practical applications of fuz

  17. Multiple-Event, Single-Photon Counting Imaging Sensor

    Science.gov (United States)

    Zheng, Xinyu; Cunningham, Thomas J.; Sun, Chao; Wang, Kang L.

    2011-01-01

    The single-photon counting imaging sensor is typically an array of silicon Geiger-mode avalanche photodiodes that are monolithically integrated with CMOS (complementary metal oxide semiconductor) readout, signal processing, and addressing circuits located in each pixel and the peripheral area of the chip. The major problem is its single-event method for photon count number registration. A single-event single-photon counting imaging array only allows registration of up to one photon count in each of its pixels during a frame time, i.e., the interval between two successive pixel reset operations. Since the frame time can t be too short, this will lead to very low dynamic range and make the sensor merely useful for very low flux environments. The second problem of the prior technique is a limited fill factor resulting from consumption of chip area by the monolithically integrated CMOS readout in pixels. The resulting low photon collection efficiency will substantially ruin any benefit gained from the very sensitive single-photon counting detection. The single-photon counting imaging sensor developed in this work has a novel multiple-event architecture, which allows each of its pixels to register as more than one million (or more) photon-counting events during a frame time. Because of a consequently boosted dynamic range, the imaging array of the invention is capable of performing single-photon counting under ultra-low light through high-flux environments. On the other hand, since the multiple-event architecture is implemented in a hybrid structure, back-illumination and close-to-unity fill factor can be realized, and maximized quantum efficiency can also be achieved in the detector array.

  18. The Connection Between X-ray Binaries and Star Clusters in NGC 4449

    CERN Document Server

    Rangelov, Blagoy; Chandar, Rupali

    2011-01-01

    We present 23 candidate X-ray binaries with luminosities down to 1.8x10^36 erg/s, in the nearby starburst galaxy NGC 4449, from observations totaling 105 ksec taken with the ACIS-S instrument on the Chandra Space Telescope. We determine count rates, luminosities, and colors for each source, and perform spectral fits for sources with sufficient counts. We also compile a new catalog of 129 compact star clusters in NGC 4449 from high resolution, multi-band optical images taken with the Hubble Space Telescope, doubling the number of clusters known in this galaxy. The UBVI,Ha luminosities of each cluster are compared with predictions from stellar evolution models to estimate their ages and masses. We find strong evidence for a population of very young massive, black-hole binaries, which comprise nearly 50% of the detected X-ray binaries in NGC 4449. Approximately a third of these remain within their parent star clusters, which formed t < 6-8 Myr ago, while others have likely been ejected from their parent clust...

  19. Eulerian numbers

    CERN Document Server

    Petersen, T Kyle

    2015-01-01

    This text presents the Eulerian numbers in the context of modern enumerative, algebraic, and geometric combinatorics. The book first studies Eulerian numbers from a purely combinatorial point of view, then embarks on a tour of how these numbers arise in the study of hyperplane arrangements, polytopes, and simplicial complexes. Some topics include a thorough discussion of gamma-nonnegativity and real-rootedness for Eulerian polynomials, as well as the weak order and the shard intersection order of the symmetric group. The book also includes a parallel story of Catalan combinatorics, wherein the Eulerian numbers are replaced with Narayana numbers. Again there is a progression from combinatorics to geometry, including discussion of the associahedron and the lattice of noncrossing partitions. The final chapters discuss how both the Eulerian and Narayana numbers have analogues in any finite Coxeter group, with many of the same enumerative and geometric properties. There are four supplemental chapters throughout, ...

  20. Fuzzy Clustering

    DEFF Research Database (Denmark)

    Berks, G.; Keyserlingk, Diedrich Graf von; Jantzen, Jan

    2000-01-01

    A symptom is a condition indicating the presence of a disease, especially, when regarded as an aid in diagnosis.Symptoms are the smallest units indicating the existence of a disease. A syndrome on the other hand is an aggregate, set or cluster of concurrent symptoms which together indicate...... and clustering are the basic concerns in medicine. Classification depends on definitions of the classes and their required degree of participant of the elements in the cases' symptoms. In medicine imprecise conditions are the rule and therefore fuzzy methods are much more suitable than crisp ones. Fuzzy c......-mean clustering is an easy and well improved tool, which has been applied in many medical fields. We used c-mean fuzzy clustering after feature extraction from an aphasia database. Factor analysis was applied on a correlation matrix of 26 symptoms of language disorders and led to five factors. The factors...

  1. Repeatability of differential goat bulk milk culture and associations with somatic cell count, total bacterial count, and standard plate count

    NARCIS (Netherlands)

    Koop, G.; Dik, N.; Nielen, M.; Lipman, L.J.A.

    2010-01-01

    The aims of this study were to assess how different bacterial groups in bulk milk are related to bulk milk somatic cell count (SCC), bulk milk total bacterial count (TBC), and bulk milk standard plate count (SPC) and to measure the repeatability of bulk milk culturing. On 53 Dutch dairy goat farms,

  2. Counting colorings of a regular graph

    CERN Document Server

    Galvin, David

    2012-01-01

    At most how many (proper) q-colorings does a regular graph admit? Galvin and Tetali conjectured that among all n-vertex, d-regular graphs with 2d|n, none admits more q-colorings than the disjoint union of n/2d copies of the complete bipartite graph K_{d,d}. In this note we give asymptotic evidence for this conjecture, giving an upper bound on the number of proper q-colorings admitted by an n-vertex, d-regular graph of the form a^n b^{n(1+o(1))/d} (where a and b depend on q and where o(1) goes to 0 as d goes to infinity) that agrees up to the o(1) term with the count of q-colorings of n/2d copies of K_{d,d}. An auxiliary result is an upper bound on the number of colorings of a regular graph in terms of its independence number. For example, we show that for all even q and fixed \\epsilon > 0 there is \\delta=\\delta(\\epsilon,q) such that the number of proper q-colorings admitted by an n-vertex, d-regular graph with no independent set of size n(1-\\epsilon)/2 is at most (a-\\delta)^n.

  3. Alaska Steller Sea Lion Pup Count Database

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This database contains counts of Steller sea lion pups on rookeries in Alaska made between 1961 and 2015. Pup counts are conducted in late June-July. Pups are...

  4. CalCOFI Egg Counts Positive Tows

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish egg counts and standardized counts for eggs captured in CalCOFI icthyoplankton nets (primarily vertical [Calvet or Pairovet], oblique [bongo or ring nets], and...

  5. CalCOFI Larvae Counts Positive Tows

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish larvae counts and standardized counts for eggs captured in CalCOFI icthyoplankton nets (primarily vertical [Calvet or Pairovet], oblique [bongo or ring nets],...

  6. A general approach for cache-oblivious range reporting and approximate range counting

    DEFF Research Database (Denmark)

    Afshani, Peyman; Hamilton, Chris; Zeh, Norbert

    2010-01-01

    We present cache-oblivious solutions to two important variants of range searching: range reporting and approximate range counting. Our main contribution is a general approach for constructing cache-oblivious data structures that provide relative (1+ε)-approximations for a general class of range...... counting queries. This class includes three-sided range counting in the plane, 3-d dominance counting, and 3-d halfspace range counting. The constructed data structures use linear space and answer queries in the optimal query bound of O(logB(N/K)) block transfers in the worst case, where K is the number...... of points in the query range. As a corollary, we also obtain the first approximate 3-d halfspace range counting and 3-d dominance counting data structures with a worst-case query time of O(log(N/K)) in internal memory. An easy but important consequence of our main result is the existence of -space cache...

  7. Comparative Study of K-means and Robust Clustering

    Directory of Open Access Journals (Sweden)

    Shashi Sharma

    2013-09-01

    Full Text Available Data mining is the mechanism of implementing patterns in large amount of data sets involving methods at the intersection of artificial intelligence, machine learning, statistics, and database systems. Clustering is the very big area in which grouping of same type of objects in data mining. Clustering has divided into different categories – partitioned clustering and hierarchical clustering. In this paper we study two types of clustering first is Kmeans which is part of partitioned clustering. Kmeans clustering generates a specific number of disjoint, flat (non-hierarchical clusters. Second clustering is robust clustering which is part of hierarchical clustering. This clustering uses Jaccard coefficient instead of using the distance measures to find the similarity between the data or documents to classify the clusters. We show comparison between Kmeans clustering and robust clustering which is better for categorical data.

  8. Magnetic cluster excitations

    Science.gov (United States)

    Furrer, Albert; Waldmann, Oliver

    2013-01-01

    Magnetic clusters, i.e., assemblies of a finite number (between two or three and several hundred) of interacting spin centers which are magnetically decoupled from their environment, can be found in many materials ranging from inorganic compounds and magnetic molecules to artificial metal structures formed on surfaces and metalloproteins. Their magnetic excitation spectra are determined by the nature of the spin centers and of the magnetic interactions, and the particular arrangement of the mutual interaction paths between the spin centers. Small clusters of up to four magnetic ions are ideal model systems in which to examine the fundamental magnetic interactions, which are usually dominated by Heisenberg exchange, but often complemented by anisotropic and/or higher-order interactions. In large magnetic clusters, which may potentially deal with a dozen or more spin centers, there is the possibility of novel many-body quantum states and quantum phenomena. In this review the necessary theoretical concepts and experimental techniques to study the magnetic cluster excitations and the resulting characteristic magnetic properties are introduced, followed by examples of small clusters, demonstrating the enormous amount of detailed physical information that can be retrieved. The current understanding of the excitations and their physical interpretation in the molecular nanomagnets which represent large magnetic clusters is then presented, with a section devoted to the subclass of single-molecule magnets, distinguished by displaying quantum tunneling of the magnetization. Finally, there is a summary of some quantum many-body states which evolve in magnetic insulators characterized by built-in or field-induced magnetic clusters. The review concludes by addressing future perspectives in the field of magnetic cluster excitations.

  9. Photon Counting Using Edge-Detection Algorithm

    Science.gov (United States)

    Gin, Jonathan W.; Nguyen, Danh H.; Farr, William H.

    2010-01-01

    New applications such as high-datarate, photon-starved, free-space optical communications require photon counting at flux rates into gigaphoton-per-second regimes coupled with subnanosecond timing accuracy. Current single-photon detectors that are capable of handling such operating conditions are designed in an array format and produce output pulses that span multiple sample times. In order to discern one pulse from another and not to overcount the number of incoming photons, a detection algorithm must be applied to the sampled detector output pulses. As flux rates increase, the ability to implement such a detection algorithm becomes difficult within a digital processor that may reside within a field-programmable gate array (FPGA). Systems have been developed and implemented to both characterize gigahertz bandwidth single-photon detectors, as well as process photon count signals at rates into gigaphotons per second in order to implement communications links at SCPPM (serial concatenated pulse position modulation) encoded data rates exceeding 100 megabits per second with efficiencies greater than two bits per detected photon. A hardware edge-detection algorithm and corresponding signal combining and deserialization hardware were developed to meet these requirements at sample rates up to 10 GHz. The photon discriminator deserializer hardware board accepts four inputs, which allows for the ability to take inputs from a quadphoton counting detector, to support requirements for optical tracking with a reduced number of hardware components. The four inputs are hardware leading-edge detected independently. After leading-edge detection, the resultant samples are ORed together prior to deserialization. The deserialization is performed to reduce the rate at which data is passed to a digital signal processor, perhaps residing within an FPGA. The hardware implements four separate analog inputs that are connected through RF connectors. Each analog input is fed to a high-speed 1

  10. Monotone Hurwitz numbers in genus zero

    CERN Document Server

    Goulden, I P; Novak, Jonathan

    2012-01-01

    Hurwitz numbers count branched covers of the Riemann sphere with specified ramification data, or equivalently, transitive permutation factorizations in the symmetric group with specified cycle types. Monotone Hurwitz numbers count a restricted subset of the branched covers counted by the Hurwitz numbers, and have arisen in recent work on the the asymptotic expansion of the Harish-Chandra-Itzykson-Zuber integral. In this paper we begin a detailed study of monotone Hurwitz numbers. We prove two results that are reminiscent of those for classical Hurwitz numbers. The first is the monotone join-cut equation, a partial differential equation with initial conditions that characterizes the generating function for monotone Hurwitz numbers in arbitrary genus. The second is our main result, in which we give an explicit formula for monotone Hurwitz numbers in genus zero.

  11. Calibrating photon counts from a single image

    CERN Document Server

    Heintzmann, Rainer; Nieuwenhuizen, Robert P J; Lidke, Keith A; Rieger, Bernd

    2016-01-01

    Most image capturing devices do not directly report the number of detected photons, but a value proportional to the photoelectron charge produced in a photomultiplier tube or collected in a camera pixel. In order to establish the photon count, the gain of the device must be measured, typically by recording tens of calibration images and exploiting the linear relationship between mean intensity and its variance [vanVliet1998]. Here we propose and evaluate a method that obtains the gain from a single acquired image by quantifying out-of-band information. As noise is not limited to the cut-off frequency of the optical transfer function (OTF), estimation of the out-of-band energy relative to the total energy enables computation of the gain. We show on simulation and experimental data that this much simpler procedure, which can be retroactively applied to any image, is comparable in precision to traditional gain calibration procedures.

  12. The stabilities and electron structures of Al-Mg clusters with 18 and 20 valence electrons

    Science.gov (United States)

    Yang, Huihui; Chen, Hongshan

    2017-07-01

    The spherical jellium model predicts that metal clusters having 18 and 20 valence electrons correspond to the magic numbers and will show specific stabilities. We explore in detail the geometric structures, stabilities and electronic structures of Al-Mg clusters containing 18 and 20 valence electrons by using genetic algorithm combined with density functional theories. The stabilities of the clusters are governed by the electronic configurations and Mg/Al ratios. The clusters with lower Mg/Al ratios are more stable. The molecular orbitals accord with the shell structures predicted by the jellium model but the 2S level interweaves with the 1D levels and the 2S and 1D orbitals form a subgroup. The clusters having 20 valence electrons form closed 1S21P61D102S2 shells and show enhanced stability. The Al-Mg clusters with a valence electron count of 18 do not form closed shells because one 1D orbital is unoccupied. The ionization potential and electron affinity are closely related to the electronic configurations; their values are determined by the subgroups the HOMO or LUMO belong to. Supplementary material in the form of one pdf file available from the Journal web page at http://https://doi.org/10.1140/epjd/e2017-80042-9

  13. A new method to search for high redshift clusters using photometric redshifts

    CERN Document Server

    Castignani, Gianluca; Celotti, Annalisa; Norman, Colin

    2014-01-01

    We describe a new method (Poisson Probability Method, PPM) to search for high redshift galaxy clusters and groups by using photometric redshift information and galaxy number counts. The method relies on Poisson statistics and is primarily introduced to search for Mpc-scale environments around a specific beacon. The PPM is tailored to both the properties of the FR I radio galaxies in the Chiaberge et al. (2009) sample, that are selected within the COSMOS survey, and on the specific dataset used. We test the efficiency of our method of searching for cluster candidates against simulations. Two different approaches are adopted. i) We use two z~1 X-ray detected cluster candidates found in the COSMOS survey and we shift them to higher redshift up to z=2. We find that the PPM detects the cluster candidates up to z=1.5, and it correctly estimates both the redshift and size of the two clusters. ii) We simulate spherically symmetric clusters of different size and richness, and we locate them at different redshifts (i.e...

  14. Counting OCR errors in typeset text

    Science.gov (United States)

    Sandberg, Jonathan S.

    1995-03-01

    Frequently object recognition accuracy is a key component in the performance analysis of pattern matching systems. In the past three years, the results of numerous excellent and rigorous studies of OCR system typeset-character accuracy (henceforth OCR accuracy) have been published, encouraging performance comparisons between a variety of OCR products and technologies. These published figures are important; OCR vendor advertisements in the popular trade magazines lead readers to believe that published OCR accuracy figures effect market share in the lucrative OCR market. Curiously, a detailed review of many of these OCR error occurrence counting results reveals that they are not reproducible as published and they are not strictly comparable due to larger variances in the counts than would be expected by the sampling variance. Naturally, since OCR accuracy is based on a ratio of the number of OCR errors over the size of the text searched for errors, imprecise OCR error accounting leads to similar imprecision in OCR accuracy. Some published papers use informal, non-automatic, or intuitively correct OCR error accounting. Still other published results present OCR error accounting methods based on string matching algorithms such as dynamic programming using Levenshtein (edit) distance but omit critical implementation details (such as the existence of suspect markers in the OCR generated output or the weights used in the dynamic programming minimization procedure). The problem with not specifically revealing the accounting method is that the number of errors found by different methods are significantly different. This paper identifies the basic accounting methods used to measure OCR errors in typeset text and offers an evaluation and comparison of the various accounting methods.

  15. Digital coincidence counting - initial results

    Science.gov (United States)

    Butcher, K. S. A.; Watt, G. C.; Alexiev, D.; van der Gaast, H.; Davies, J.; Mo, Li; Wyllie, H. A.; Keightley, J. D.; Smith, D.; Woods, M. J.

    2000-08-01

    Digital Coincidence Counting (DCC) is a new technique in radiation metrology, based on the older method of analogue coincidence counting. It has been developed by the Australian Nuclear Science and Technology Organisation (ANSTO), in collaboration with the National Physical Laboratory (NPL) of the United Kingdom, as a faster more reliable means of determining the activity of ionising radiation samples. The technique employs a dual channel analogue-to-digital converter acquisition system for collecting pulse information from a 4π beta detector and an NaI(Tl) gamma detector. The digitised pulse information is stored on a high-speed hard disk and timing information for both channels is also stored. The data may subsequently be recalled and analysed using software-based algorithms. In this letter we describe some recent results obtained with the new acquistion hardware being tested at ANSTO. The system is fully operational and is now in routine use. Results for 60Co and 22Na radiation activity calibrations are presented, initial results with 153Sm are also briefly mentioned.

  16. Kinematics of Clustering

    CERN Document Server

    Wang, Steven; Metcalfe, Guy; Wu, Jie

    2014-01-01

    The dynamical system for inertial particles in fluid flow has both attracting and repelling regions, the interplay of which can localize particles. In laminar flow experiments we find that particles, initially moving throughout the fluid domain, can undergo an instability and cluster into subdomains of the fluid when the flow Reynolds number exceeds a critical value that depends on particle and fluid inertia. We derive an expression for the instability boundary and for a universal curve that describes the clustering rate for all particles.

  17. Cluster-tilting theory

    OpenAIRE

    Simões, Raquel Coelho Guardado

    2008-01-01

    Tese de mestado em Matemática (Álgebra, Lógica e Fundamentos) apresentada à Universidade de Lisboa, através da Faculdade de Ciências, 2008 Resumo alargado disponível em português The notion of Cluster Algebra first appeared in 2001, in a paper by S. Fomin and A. Zelevinsky, studying the dual canonical basis of the quantum group of a finite dimensional simple Lie algebra over the complex numbers, and also total positivity for algebraic groups. Cluster categories, introduced by A. Buan, R...

  18. Clustering of the IR Background Light with Spitzer: Contribution from Resolved Sources

    CERN Document Server

    Sullivan, I; Chary, R R; Bock, J J; Brodwin, M; Brown, M J I; Dey, A; Dickinson, M; Eisenhardt, P; Ferguson, H C; Giavalisco, M; Keating, B; Lange, A; Mobasher, B; Reach, W T; Stern, D; Wright, E L; Sullivan, Ian; Cooray, Asantha; Chary, Ranga-Ram; Bock, James J.; Brodwin, Mark; Brown, Michael J. I.; Dey, Arjun; Dickinson, Mark; Eisenhardt, Peter; Ferguson, Henry C.; Giavalisco, Mauro; Keating, Brian; Lange, Andrew; Mobasher, Bahram; Reach, William T.; Stern, Daniel; Wright, Edward L.

    2006-01-01

    We describe the angular power spectrum of resolved sources at 3.6 microns (L-band) in Spitzer imaging data of the GOODS HDF-N, the GOODS CDF-S, and the NDWFS Bootes field in several source magnitude bins. We also measure angular power spectra of resolved sources in the Bootes field at K_S and J-bands using ground-based IR imaging data. In the three bands, J, K_S, and L, we detect the clustering of galaxies on top of the shot-noise power spectrum at multipoles between ell ~ 10^2 and 10^5. The angular power spectra range from the large, linear scales to small, non-linear scales of galaxy clustering, and in some magnitude ranges, show departure from a power-law clustering spectrum. We consider a halo model to describe clustering measurements and to establish the halo occup ation number parameters of IR bright galaxies at redshifts around one. We also extend our clustering results and completeness-corrected faint source number counts in GOODS fields to understand the underlying nature of unresolved sources respon...

  19. Fuzzy clustering of mechanisms

    Indian Academy of Sciences (India)

    Amitabha Ghosh; Dilip Kumar Pratihar; M V V Amarnath; Guenter Dittrich; Jorg Mueller

    2012-10-01

    During the course of development of Mechanical Engineering, a large number of mechanisms (that is, linkages to perform various types of tasks) have been conceived and developed. Quite a few atlases and catalogues were prepared by the designers of machines and mechanical systems. However, often it is felt that a clustering technique for handling the list of large number of mechanisms can be very useful,if it is developed based on a scientific principle. In this paper, it has been shown that the concept of fuzzy sets can be conveniently used for this purpose, if an adequate number of properly chosen attributes (also called characteristics) are identified. Using two clustering techniques, the mechanisms have been classified in the present work and in future, it may be extended to develop an expert system, which can automate type synthesis phase of mechanical design. To the best of the authors’ knowledge, this type of clustering of mechanisms has not been attempted before. Thus, this is the first attempt to cluster the mechanisms based on some quantitative measures. It may help the engineers to carry out type synthesis of the mechanisms.

  20. How much do women count if they not counted?

    Directory of Open Access Journals (Sweden)

    Federica Taddia

    2006-01-01

    Full Text Available The condition of women throughout the world is marked by countless injustices and violations of the most fundamental rights established by the Universal Declaration of human rights and every culture is potentially prone to commit discrimination against women in various forms. Women are worse fed, more exposed to physical violence, more exposed to diseases and less educated; they have less access to, or are excluded from, vocational training paths; they are the most vulnerable among prisoners of conscience, refugees and immigrants and the least considered within ethnic minorities; from their very childhood, women are humiliated, undernourished, sold, raped and killed; their work is generally less paid compared to men’s work and in some countries they are victims of forced marriages. Such condition is the result of old traditions that implicit gender-differentiated education has long promoted through cultural models based on theories, practices and policies marked by discrimination and structured differentially for men and women. Within these cultural models, the basic educational institutions have played and still play a major role in perpetuating such traditions. Nevertheless, if we want to overcome inequalities and provide women with empowerment, we have to start right from the educational institutions and in particular from school, through the adoption of an intercultural approach to education: an approach based on active pedagogy and on methods of analysis, exchange and enhancement typical of socio-educational animation. The intercultural approach to education is attentive to promote the realisation of each individual and the dignity and right of everyone to express himself/herself in his/her own way. Such an approach will give women the opportunity to become actual agents of collective change and to get the strength and wellbeing necessary to count and be counted as human beings entitled to freedom and equality, and to have access to all