WorldWideScience

Sample records for scalable halo finder

  1. BASSET: Scalable Gateway Finder in Large Graphs

    Energy Technology Data Exchange (ETDEWEB)

    Tong, H; Papadimitriou, S; Faloutsos, C; Yu, P S; Eliassi-Rad, T

    2010-11-03

    Given a social network, who is the best person to introduce you to, say, Chris Ferguson, the poker champion? Or, given a network of people and skills, who is the best person to help you learn about, say, wavelets? The goal is to find a small group of 'gateways': persons who are close enough to us, as well as close enough to the target (person, or skill) or, in other words, are crucial in connecting us to the target. The main contributions are the following: (a) we show how to formulate this problem precisely; (b) we show that it is sub-modular and thus it can be solved near-optimally; (c) we give fast, scalable algorithms to find such gateways. Experiments on real data sets validate the effectiveness and efficiency of the proposed methods, achieving up to 6,000,000x speedup.

  2. The ROCKSTAR Phase-space Temporal Halo Finder and the Velocity Offsets of Cluster Cores

    Science.gov (United States)

    Behroozi, Peter S.; Wechsler, Risa H.; Wu, Hao-Yi

    2013-01-01

    We present a new algorithm for identifying dark matter halos, substructure, and tidal features. The approach is based on adaptive hierarchical refinement of friends-of-friends groups in six phase-space dimensions and one time dimension, which allows for robust (grid-independent, shape-independent, and noise-resilient) tracking of substructure; as such, it is named ROCKSTAR (Robust Overdensity Calculation using K-Space Topologically Adaptive Refinement). Our method is massively parallel (up to 105 CPUs) and runs on the largest current simulations (>1010 particles) with high efficiency (10 CPU hours and 60 gigabytes of memory required per billion particles analyzed). A previous paper has shown ROCKSTAR to have excellent recovery of halo properties; we expand on these comparisons with more tests and higher-resolution simulations. We show a significant improvement in substructure recovery compared to several other halo finders and discuss the theoretical and practical limits of simulations in this regard. Finally, we present results that demonstrate conclusively that dark matter halo cores are not at rest relative to the halo bulk or substructure average velocities and have coherent velocity offsets across a wide range of halo masses and redshifts. For massive clusters, these offsets can be up to 350 km s-1 at z = 0 and even higher at high redshifts. Our implementation is publicly available at http://code.google.com/p/rockstar.

  3. Gravitationally Consistent Halo Catalogs and Merger Trees for Precision Cosmology

    Science.gov (United States)

    Behroozi, Peter S.; Wechsler, Risa H.; Wu, Hao-Yi; Busha, Michael T.; Klypin, Anatoly A.; Primack, Joel R.

    2013-01-01

    We present a new algorithm for generating merger trees and halo catalogs which explicitly ensures consistency of halo properties (mass, position, and velocity) across time steps. Our algorithm has demonstrated the ability to improve both the completeness (through detecting and inserting otherwise missing halos) and purity (through detecting and removing spurious objects) of both merger trees and halo catalogs. In addition, our method is able to robustly measure the self-consistency of halo finders; it is the first to directly measure the uncertainties in halo positions, halo velocities, and the halo mass function for a given halo finder based on consistency between snapshots in cosmological simulations. We use this algorithm to generate merger trees for two large simulations (Bolshoi and Consuelo) and evaluate two halo finders (ROCKSTAR and BDM). We find that both the ROCKSTAR and BDM halo finders track halos extremely well; in both, the number of halos which do not have physically consistent progenitors is at the 1%-2% level across all halo masses. Our code is publicly available at http://code.google.com/p/consistent-trees. Our trees and catalogs are publicly available at http://hipacc.ucsc.edu/Bolshoi/.

  4. Friend Finder (Game)

    Science.gov (United States)

    ... Credit Homes & Mortgages Health & Fitness Jobs & Making Money Privacy, Identity & Online Security Blog Video & Media Friend Finder Scam Alerts Looking for Business Guidance? Get Email Updates Blog ... Privacy Policy About Us Contact Us Share Our Resources. ...

  5. Healthcare Finder API

    Data.gov (United States)

    U.S. Department of Health & Human Services — All of the data used on the Finder.HealthCare.gov web application is available through this API. There are multiple collections of data available through the API. 1....

  6. BS-virus-finder

    DEFF Research Database (Denmark)

    Gao, Shengjie; Hu, Xuesong; Xu, Fengping

    2018-01-01

    Background: DNA methylation plays a key role in the regulation of gene expression and carcinogenesis. Bisulfite sequencing studies mainly focus on calling SNP, DMR, and ASM. Until now, only a few software tools focus on virus integration using bisulfite sequencing data. Findings: We have developed...... a new and easy-to-use software tool, named BS-virus-finder (BSVF, RRID:SCR_015727), to detect viral integration breakpoints in whole human genomes. The tool is hosted at https://github.com/BGI-SZ/BSVF. Conclusions: BS-virus-finder demonstrates high sensitivity and specificity. It is useful in epigenetic...... studies and to reveal the relationship between viral integration and DNA methylation. BS-virus-finder is the first software tool to detect virus integration loci by using bisulfite sequencing data....

  7. BookFinder.com

    CERN Document Server

    BookFinder.com is produced by the bibliophiles at 13th Generation Media of Berkeley, California. Our goal is to provide fellow readers unbiased realtime information about books available online. Rather than selling books ourselves (does the world rea Amazon.com wannabe?), we've teamed up with over 15,000 of the finest booksellers online to bring you the largest book catalog available anywhere, either online or offline.

  8. IdentiFINDER Laboratory Exercise

    Energy Technology Data Exchange (ETDEWEB)

    Weinmann-Smith, Robert [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-09-21

    The identiFINDER2 is an easily portable handheld NaI gamma detector. The IAEA uses the safeguards version of the identiFINDER2 and calls it the HM-5. The HM-5 has built in software to analyze the detection signal specifically for IAEA verification applications.

  9. Artificial halos

    Science.gov (United States)

    Selmke, Markus

    2015-09-01

    Judged by their frequency and beauty, ice halos easily rival rainbows as a prominent atmospheric optics phenomenon. This article presents experimental halo demonstrations of varying complexity. Using a single commercially available hexagonal glass prism, a variety of artificial halos can be simulated. The experiments include laser beam path analysis, a modified classic spinning prism experiment, and a novel Monte-Carlo machine for three-dimensional rotations. Each of these experiments emulates different conditions of certain halo displays, and in combination, they allow a thorough understanding of these striking phenomena.

  10. Introduction to IdentiFINDERs

    Energy Technology Data Exchange (ETDEWEB)

    Rees, Brian G. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2018-02-05

    These are slides from a presentation. The identiFINDER provides information on radiation levels. It can automatically identify isotopes in its library. It can save spectra for transfer to a computer, and has a 4-8 hour battery life. The following is covered: an overview, operating modes, getting started, finder mode, search, identification mode, dose & rate, warning & alarm, options (ultra LGH), options (identifinder2), and general procedure.

  11. Software review: SciFinder

    OpenAIRE

    Cavaller, Víctor

    2008-01-01

    SciFinder is a CAS software client application designed primarily for use by professional chemists in commercial organizations. Versions for both Windows and Macintosh operating systems are available. SciFinder Scholar is a version designed for universities and other academic institutions and lacks some supplementary features for multi-database searching. They are both designed with a graphic interface, making them both particularly suitable for searching the Registry file for ...

  12. N-body dark matter haloes with simple hierarchical histories

    Science.gov (United States)

    Jiang, Lilian; Helly, John C.; Cole, Shaun; Frenk, Carlos S.

    2014-05-01

    We present a new algorithm which groups the subhaloes found in cosmological N-body simulations by structure finders such as SUBFIND into dark matter haloes whose formation histories are strictly hierarchical. One advantage of these `Dhaloes' over the commonly used friends-of-friends (FoF) haloes is that they retain their individual identity in the cases when FoF haloes are artificially merged by tenuous bridges of particles or by an overlap of their outer diffuse haloes. Dhaloes are thus well suited for modelling galaxy formation and their merger trees form the basis of the Durham semi-analytic galaxy formation model, GALFORM. Applying the Dhalo construction to the Λ cold dark matter Millennium II Simulation, we find that approximately 90 per cent of Dhaloes have a one-to-one, bijective match with a corresponding FoF halo. The remaining 10 per cent are typically secondary components of large FoF haloes. Although the mass functions of both types of haloes are similar, the mass of Dhaloes correlates much more tightly with the virial mass, M200, than FoF haloes. Approximately 80 per cent of FoF and bijective and non-bijective Dhaloes are relaxed according to standard criteria. For these relaxed haloes, all three types have similar concentration-M200 relations and, at fixed mass, the concentration distributions are described accurately by log-normal distributions.

  13. Symbolic PathFinder v7

    DEFF Research Database (Denmark)

    Luckow, Kasper Søe; Păsăreanu, Corina

    2014-01-01

    We describe Symbolic PathFinder v7 in terms of its updated design addressing the changes of Java PathFinder v7 and of its new optimization when computing path conditions. Furthermore, we describe the Symbolic Execution Tree Extension; a newly added feature that allows for outputting the symbolic...

  14. Borromean halo, Tango halo, and halo isomers in atomic nuclei

    Science.gov (United States)

    Izosimov, Igor

    2016-01-01

    Structure of the ground and excited states in halo-like nuclei is discussed. Both the Borromean and tango halo types can be observed for n-p configurations of atomic nuclei.Structure of the halo may be different for the different levels and resonances in atomic nuclei. Isobar analog, double isobar analog, configuration, and double configuration states can simultaneously have n-n, n-p, and p-p halo components in their wave functions. When the halo structure of the excited state differs from that of the ground state, or the ground state has non-halo structure, the γ-transition from the excited state to the ground state can be essentially hindered, i.e. the formation of a specific type of isomers (halo isomers) becomes possible. B(Mγ) and B(Eγ) values for γ-transitions in 6,7,8Li, 8,9,10Be, 8,10,11B, 10,11,12,13,14C, 13,14,15,16,17N, 15,16,17,19O, and 17F are analyzed. Special attention is given to nuclei which ground state does not exhibit halo structure but the excited state (halo isomer) may have one.

  15. Scalable devices

    KAUST Repository

    Krüger, Jens J.

    2014-01-01

    In computer science in general and in particular the field of high performance computing and supercomputing the term scalable plays an important role. It indicates that a piece of hardware, a concept, an algorithm, or an entire system scales with the size of the problem, i.e., it can not only be used in a very specific setting but it\\'s applicable for a wide range of problems. From small scenarios to possibly very large settings. In this spirit, there exist a number of fixed areas of research on scalability. There are works on scalable algorithms, scalable architectures but what are scalable devices? In the context of this chapter, we are interested in a whole range of display devices, ranging from small scale hardware such as tablet computers, pads, smart-phones etc. up to large tiled display walls. What interests us mostly is not so much the hardware setup but mostly the visualization algorithms behind these display systems that scale from your average smart phone up to the largest gigapixel display walls.

  16. Testing approximate predictions of displacements of cosmological dark matter halos

    Science.gov (United States)

    Munari, Emiliano; Monaco, Pierluigi; Koda, Jun; Kitaura, Francisco-Shu; Sefusatti, Emiliano; Borgani, Stefano

    2017-07-01

    We present a test to quantify how well some approximate methods, designed to reproduce the mildly non-linear evolution of perturbations, are able to reproduce the clustering of DM halos once the grouping of particles into halos is defined and kept fixed. The following methods have been considered: Lagrangian Perturbation Theory (LPT) up to third order, Truncated LPT, Augmented LPT, MUSCLE and COLA. The test runs as follows: halos are defined by applying a friends-of-friends (FoF) halo finder to the output of an N-body simulation. The approximate methods are then applied to the same initial conditions of the simulation, producing for all particles displacements from their starting position and velocities. The position and velocity of each halo are computed by averaging over the particles that belong to that halo, according to the FoF halo finder. This procedure allows us to perform a well-posed test of how clustering of the matter density and halo density fields are recovered, without asking to the approximate method an accurate reconstruction of halos. We have considered the results at z=0,0.5,1, and we have analysed power spectrum in real and redshift space, object-by-object difference in position and velocity, density Probability Distribution Function (PDF) and its moments, phase difference of Fourier modes. We find that higher LPT orders are generally able to better reproduce the clustering of halos, while little or no improvement is found for the matter density field when going to 2LPT and 3LPT. Augmentation provides some improvement when coupled with 2LPT, while its effect is limited when coupled with 3LPT. Little improvement is brought by MUSCLE with respect to Augmentation. The more expensive particle-mesh code COLA outperforms all LPT methods, and this is true even for mesh sizes as large as the inter-particle distance. This test sets an upper limit on the ability of these methods to reproduce the clustering of halos, for the cases when these objects are

  17. Isospin in halo nuclei: Borromean halo, tango halo, and halo isomers

    Science.gov (United States)

    Izosimov, I. N.

    2017-09-01

    It is shown that the wave functions for isobaric analog, double isobaric analog, configuration, and double configuration states may simultaneously have components corresponding to nn, np, and pp halos. The difference in the halo structure between the ground and excited states of a nucleus may lead to the formation of halo isomers. A halo structure of both Borromean and tango types can be observed for np configurations. The structure of ground and excited states with various isospins in halo-like nuclei is discussed. The reduced probabilities B( Mλ) and B( Eλ) for gamma transitions in 6-8Li, 8-10Be, 8,10,11B, 10-14C, 13-17N, 15-17,19O, and 17F nuclei are analyzed. Particular attention is given to the cases where the ground state of a nucleus does not have a halo structure, but where its excited state may have it.

  18. Automatic generation of gene finders for eukaryotic species

    DEFF Research Database (Denmark)

    Terkelsen, Kasper Munch; Krogh, A.

    2006-01-01

    Background The number of sequenced eukaryotic genomes is rapidly increasing. This means that over time it will be hard to keep supplying customised gene finders for each genome. This calls for procedures to automatically generate species-specific gene finders and to re-train them as the quantity...... length distributions. The performance of each individual gene predictor on each individual genome is comparable to the best of the manually optimised species-specific gene finders. It is shown that species-specific gene finders are superior to gene finders trained on other species....

  19. On the shape of dark matter haloes from MultiDark Planck simulations

    Science.gov (United States)

    Vega-Ferrero, Jesús; Yepes, Gustavo; Gottlöber, Stefan

    2017-05-01

    The halo shape plays a central role in determining important observational properties of the haloes such as mass, concentration and lensing cross-sections. The triaxiality of lensing galaxy clusters has a substantial impact on the distribution of the largest Einstein radii, while weak lensing techniques are sensitive to the intrinsic halo ellipticity. In this work, we provide scaling relations for the shapes of dark matter haloes as a function of mass (peak height) and redshift over more than four orders of magnitude in halo masses, namely from 1011.5 to 1015.8 h-1 M⊙. We have analysed four dark matter only simulations from the MultiDark cosmological simulation suite with more than 56 billion particles within boxes of 4.0, 2.5, 1.0 and 0.4 h-1 Gpc size assuming Planck cosmology. The dark matter haloes have been identified in the simulations using the rockstar halo finder, which also determines the axis ratios in terms of the diagonalization of the inertia tensor. In order to infer the shape for a hypothetical halo of a given mass at a given redshift, we provide fitting functions to the minor-to-major and intermediate-to-major axis ratios as a function of the peak height.

  20. ALFA beam halo

    CERN Document Server

    Komarek, Tomas

    2014-01-01

    This note serves as a final report about CERN Summer Student Programme 2014 project. The beam halo is an undesired phenomenon for physics analyses on particle accelerators. It surrounds the beam core and constitutes an important part of background for signal measurements on some detectors, eg. in the forward region. In this study, the data from the ALFA detector were used, specifically from the run 191373 ($\\beta^*=90\\unit{m}$) and the run 213268 ($\\beta^*=1\\unit{km}$). Using the ROOT framework, a software for beam halo events selection was created and beam halo properties were examined. In the run 213268, excessive beam halo is suspected to be the reason for multiple beam scrapings that occurred. A kinematic reconstruction of beam halo particles is attempted in order to understand beam halo properties in the interaction point. Some further simulations are employed to find constraints for beam halo particles in order to survive in the accelerator for a longer time/many revolutions. This work represents a st...

  1. Basic Testing of the DUCHAMP Source Finder

    Science.gov (United States)

    Westmeier, T.; Popping, A.; Serra, P.

    2012-01-01

    This paper presents and discusses the results of basic source finding tests in three dimensions (using spectroscopic data cubes) with DUCHAMP, the standard source finder for the Australian Square Kilometre Array Pathfinder. For this purpose, we generated different sets of unresolved and extended Hi model sources. These models were then fed into DUCHAMP, using a range of different parameters and methods provided by the software. The main aim of the tests was to study the performance of DUCHAMP on sources with different parameters and morphologies and assess the accuracy of DUCHAMP's source parametrisation. Overall, we find DUCHAMP to be a powerful source finder capable of reliably detecting sources down to low signal-to-noise ratios and accurately measuring their position and velocity. In the presence of noise in the data, DUCHAMP's measurements of basic source parameters, such as spectral line width and integrated flux, are affected by systematic errors. These errors are a consequence of the effect of noise on the specific algorithms used by DUCHAMP for measuring source parameters in combination with the fact that the software only takes into account pixels above a given flux threshold and hence misses part of the flux. In scientific applications of DUCHAMP these systematic errors would have to be corrected for. Alternatively, DUCHAMP could be used as a source finder only, and source parametrisation could be done in a second step using more sophisticated parametrisation algorithms.

  2. What's a Halo?

    Science.gov (United States)

    ... Development Infections Diseases & Conditions Pregnancy & Baby Nutrition & Fitness Emotions & Behavior School & Family Life First Aid & Safety Doctors & ... of quick or jerky movements, like jumping or dancing pulling or tugging on the halo or attached ...

  3. Target & Propagation Models for the FINDER Radar

    Science.gov (United States)

    Cable, Vaughn; Lux, James; Haque, Salmon

    2013-01-01

    Finding persons still alive in piles of rubble following an earthquake, a severe storm, or other disaster is a difficult problem. JPL is currently developing a victim detection radar called FINDER (Finding Individuals in Emergency and Response). The subject of this paper is directed toward development of propagation & target models needed for simulation & testing of such a system. These models are both physical (real rubble piles) and numerical. Early results from the numerical modeling phase show spatial and temporal spreading characteristics when signals are passed through a randomly mixed rubble pile.

  4. 12 CFR 7.1002 - National bank acting as finder.

    Science.gov (United States)

    2010-01-01

    ... parties to a transaction. (b) Permissible finder activities. A national bank that acts as a finder may... for a transaction that the parties themselves negotiate and consummate. The following list provides... between interested parties expressions of interest, bids, offers, orders, and confirmations relating to a...

  5. Comparison of Potential ASKAP HI Survey Source Finders

    Science.gov (United States)

    Popping, A.; Jurek, R.; Westmeier, T.; Serra, P.; Flöer, L.; Meyer, M.; Koribalski, B.

    2012-02-01

    The large size of the ASKAP HI surveys DINGO and WALLABY necessitates automated 3D source finding. A performance difference of a few percent corresponds to a significant number of galaxies being detected or undetected. As such, the performance of the automated source finding is of paramount importance to both of these surveys. We have analysed the performance of various source finders to determine which will allow us to meet our survey goals during the DINGO and WALLABY design studies. Here we present a comparison of the performance of five different methods of automated source finding. These source finders are duchamp, gamma-finder, a CNHI finder, a 2d-1d wavelet reconstruction finder and a sigma clipping method (s+c finder). Each source finder was applied to the same three-dimensional data cubes containing (a) point sources with a Gaussian velocity profile and (b) spatially extended model-galaxies with inclinations and rotation profiles. We focus on the completeness and reliability of each algorithm when comparing the performance of the different source finders.

  6. Spectrum of Sprite Halos

    Czech Academy of Sciences Publication Activity Database

    Gordillo-Vázquez, F.J.; Luque, A.; Šimek, Milan

    2011-01-01

    Roč. 116, č. 9 (2011), A09319-A09319 ISSN 0148-0227 Institutional research plan: CEZ:AV0Z20430508 Keywords : sprites * halos * spectroscopy Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 3.021, year: 2011 http://www.trappa.iaa.es/sites/all/files/papers/isi_journal_papers/2011/2011_08.pdf

  7. Highly scalable Ab initio genomic motif identification

    KAUST Repository

    Marchand, Benoit

    2011-01-01

    We present results of scaling an ab initio motif family identification system, Dragon Motif Finder (DMF), to 65,536 processor cores of IBM Blue Gene/P. DMF seeks groups of mutually similar polynucleotide patterns within a set of genomic sequences and builds various motif families from them. Such information is of relevance to many problems in life sciences. Prior attempts to scale such ab initio motif-finding algorithms achieved limited success. We solve the scalability issues using a combination of mixed-mode MPI-OpenMP parallel programming, master-slave work assignment, multi-level workload distribution, multi-level MPI collectives, and serial optimizations. While the scalability of our algorithm was excellent (94% parallel efficiency on 65,536 cores relative to 256 cores on a modest-size problem), the final speedup with respect to the original serial code exceeded 250,000 when serial optimizations are included. This enabled us to carry out many large-scale ab initio motiffinding simulations in a few hours while the original serial code would have needed decades of execution time. Copyright 2011 ACM.

  8. Tracking the LHC halo

    CERN Document Server

    Antonella Del Rosso

    2015-01-01

    In the LHC, beams of 25-ns-spaced proton bunches travel at almost the speed of light and pass through many different devices installed along the ring that monitor their properties. During their whirling motion, beam particles might interact with the collimation instrumentation or with residual gas in the vacuum chambers and this creates the beam halo – an annoying source of background for the physics data. Newly installed CMS sub-detectors are now able to monitor it.   The Beam Halo Monitors (BHM) are installed around the CMS rotating shielding. The BHM are designed and built by University of Minnesota, CERN, Princeton University, INFN Bologna and the National Technical University of Athens. (Image: Andrea Manna). The Beam Halo Monitor (BHM) is a set of 20 Cherenkov radiators – 10-cm-long quartz crystals – installed at each end of the huge CMS detector. Their design goal is to measure the particles that can cause the so-called “machine-induced...

  9. KOJAK Group Finder: Scalable Group Detection via Integrated Knowledge-Based and Statistical Reasoning

    Science.gov (United States)

    2006-09-01

    evidence of communication events, business transactions, familial relationships, etc. For unknown groups neither name nor known members are available...evidence of communication events, business transactions, familial relationships, etc. For unknown groups neither name nor known members are available. All...STELLA and PowerLoomn. These modules comunicate with a knowledge basec using KIF and stan(lardl relational database systelnis using either standard

  10. Terrestrial Planet Finder Coronagraph High Accuracy Optical Propagation Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Terrestrial Planet Finder (TPF) project is considering several approaches to discovering planets orbiting stars far from earth and assessing their suitability to...

  11. STEME: a robust, accurate motif finder for large data sets.

    Directory of Open Access Journals (Sweden)

    John E Reid

    Full Text Available Motif finding is a difficult problem that has been studied for over 20 years. Some older popular motif finders are not suitable for analysis of the large data sets generated by next-generation sequencing. We recently published an efficient approximation (STEME to the EM algorithm that is at the core of many motif finders such as MEME. This approximation allows the EM algorithm to be applied to large data sets. In this work we describe several efficient extensions to STEME that are based on the MEME algorithm. Together with the original STEME EM approximation, these extensions make STEME a fully-fledged motif finder with similar properties to MEME. We discuss the difficulty of objectively comparing motif finders. We show that STEME performs comparably to existing prominent discriminative motif finders, DREME and Trawler, on 13 sets of transcription factor binding data in mouse ES cells. We demonstrate the ability of STEME to find long degenerate motifs which these discriminative motif finders do not find. As part of our method, we extend an earlier method due to Nagarajan et al. for the efficient calculation of motif E-values. STEME's source code is available under an open source license and STEME is available via a web interface.

  12. The Effects of Varying Cosmological Parameters on Halo Substructure

    Science.gov (United States)

    Dooley, Gregory A.; Griffen, Brendan F.; Zukin, Phillip; Ji, Alexander P.; Vogelsberger, Mark; Hernquist, Lars E.; Frebel, Anna

    2014-05-01

    We investigate how different cosmological parameters, such as those delivered by the WMAP and Planck missions, affect the nature and evolution of the dark matter halo substructure. We use a series of flat Λ cold dark matter cosmological N-body simulations of structure formation, each with a different power spectrum but with the same initial white noise field. Our fiducial simulation is based on parameters from the WMAP seventh year cosmology. We then systematically vary the spectral index, ns ; matter density, Ω M ; and normalization of the power spectrum, σ8, for seven unique simulations. Across these, we study variations in the subhalo mass function, mass fraction, maximum circular velocity function, spatial distribution, concentration, formation times, accretion times, and peak mass. We eliminate dependence of subhalo properties on host halo mass and average the values over many hosts to reduce variance. While the "same" subhalos from identical initial overdensity peaks in higher σ8, ns , and Ω m simulations accrete earlier and end up less massive and closer to the halo center at z = 0, the process of continuous subhalo accretion and destruction leads to a steady state distribution of these properties across all subhalos in a given host. This steady state mechanism eliminates cosmological dependence on all of the properties listed above except for subhalo concentration and V max, which remain greater for higher σ8, ns , and Ω m simulations, and subhalo formation time, which remains earlier. We also find that the numerical technique for computing the scale radius and the halo finder that were used can significantly affect the concentration-mass relationship as computed for a simulation.

  13. Cosmic web type dependence of halo clustering

    Science.gov (United States)

    Fisher, J. D.; Faltenbacher, A.

    2018-01-01

    We use the Millennium Simulation to show that halo clustering varies significantly with cosmic web type. Haloes are classified as node, filament, sheet and void haloes based on the eigenvalue decomposition of the velocity shear tensor. The velocity field is sampled by the peculiar velocities of a fixed number of neighbouring haloes, and spatial derivatives are computed using a kernel borrowed from smoothed particle hydrodynamics. The classification scheme is used to examine the clustering of haloes as a function of web type for haloes with masses larger than 1011 h- 1 M⊙. We find that node haloes show positive bias, filament haloes show negligible bias and void and sheet haloes are antibiased independent of halo mass. Our findings suggest that the mass dependence of halo clustering is rooted in the composition of web types as a function of halo mass. The substantial fraction of node-type haloes for halo masses ≳ 2 × 1013 h- 1 M⊙ leads to positive bias. Filament-type haloes prevail at intermediate masses, 1012-1013 h- 1 M⊙, resulting in unbiased clustering. The large contribution of sheet-type haloes at low halo masses ≲ 1012 h- 1 M⊙ generates antibiasing.

  14. Black holes with halos

    Science.gov (United States)

    Monten, Ruben; Toldo, Chiara

    2018-02-01

    We present new AdS4 black hole solutions in N =2 gauged supergravity coupled to vector and hypermultiplets. We focus on a particular consistent truncation of M-theory on the homogeneous Sasaki–Einstein seven-manifold M 111, characterized by the presence of one Betti vector multiplet. We numerically construct static and spherically symmetric black holes with electric and magnetic charges, corresponding to M2 and M5 branes wrapping non-contractible cycles of the internal manifold. The novel feature characterizing these nonzero temperature configurations is the presence of a massive vector field halo. Moreover, we verify the first law of black hole mechanics and we study the thermodynamics in the canonical ensemble. We analyze the behavior of the massive vector field condensate across the small-large black hole phase transition and we interpret the process in the dual field theory.

  15. Tracking of Humans and Robots Using Laser Range Finders

    Science.gov (United States)

    Bršcic, Drazen; Sasaki, Takeshi; Hashimoto, Hideki

    There exist various applications where tracking of humans or robots in an area is needed. An example of such applications are Intelligent Spaces, where humans and robots share a common space and their positions are tracked by a system of sensors in the space. In this paper a system for tracking both humans and robots that utilizes laser range finders as sensing devices is described. The details of the extraction of objects from the laser scan, data association and estimation are given, and results of tracking humans and robots are described. Calibration of the distributed laser range finders, which is important for the operation of the tracking system is also described, both in a manual and automated variant and experimental results are given. Finally, the inclusion of a laser range finder onboard the mobile robot in the tracking process is described and accompanied with experimental results. The distributed fusion of static and onboard sensors is also discussed.

  16. The Excursion Set Theory of Halo Mass Functions, Halo Clustering, and Halo Growth

    Science.gov (United States)

    Zentner, Andrew R.

    I review the excursion set theory with particular attention toward applications to cold dark matter halo formation and growth, halo abundance, and halo clustering. After a brief introduction to notation and conventions, I begin by recounting the heuristic argument leading to the mass function of bound objects given by Press and Schechter. I then review the more formal derivation of the Press-Schechter halo mass function that makes use of excursion sets of the density field. The excursion set formalism is powerful and can be applied to numerous other problems. I review the excursion set formalism for describing both halo clustering and bias and the properties of void regions. As one of the most enduring legacies of the excursion set approach and one of its most common applications, I spend considerable time reviewing the excursion set theory of halo growth. This section of the review culminates with the description of two Monte Carlo methods for generating ensembles of halo mass accretion histories. In the last section, I emphasize that the standard excursion set approach is the result of several simplifying assumptions. Dropping these assumptions can lead to more faithful predictions and open excursion set theory to new applications. One such assumption is that the height of the barriers that define collapsed objects is a constant function of scale. I illustrate the implementation of the excursion set approach for barriers of arbitrary shape. One such application is the now well-known improvement of the excursion set mass function derived from the "moving" barrier for ellipsoidal collapse. I also emphasize that the statement that halo accretion histories are independent of halo environment in the excursion set approach is not a general prediction of the theory. It is a simplifying assumption. I review the method for constructing correlated random walks of the density field in the more general case. I construct a simple toy model to illustrate that excursion set

  17. Colección programas: SciFinder

    OpenAIRE

    Cavaller, Víctor

    2008-01-01

    SciFinder es un software informático de CAS diseñado principalmente para el uso por parte de químicos profesionales de organizaciones comerciales. Existen versiones tanto para S.O. Windows como para Macintosh. SciFinder Scholar es la versión pensada para universidades y otras instituciones académicas, en la cual no están presentes ciertas características para búsquedas en varias bases de datos a la vez. Las dos versiones han sido diseñadas con interfaces gráficas, y por eso son...

  18. 4D Cellular Automaton Track Finder in the CBM Experiment

    Directory of Open Access Journals (Sweden)

    Akishina Valentina

    2016-01-01

    The FLES reconstruction and selection package consists of several modules: track finding, track fitting, short-lived particles finding, event building and event selection. The Cellular Automaton (CA track finder algorithm was adapted towards time-based reconstruction. In this article, we describe in detail the modification done to the algorithm, as well as the performance of the developed time-based CA approach.

  19. SearchResultFinder: federated search made easy

    NARCIS (Netherlands)

    Trieschnigg, Rudolf Berend; Tjin-Kam-Jet, Kien; Hiemstra, Djoerd

    Building a federated search engine based on a large number existing web search engines is a challenge: implementing the programming interface (API) for each search engine is an exacting and time-consuming job. In this demonstration we present SearchResultFinder, a browser plugin which speeds up

  20. SciFinder: guia ràpida. Desembre 2014

    OpenAIRE

    Universitat de Barcelona. CRAI

    2014-01-01

    SciFinder és una plataforma produïda pel Chemical Abstracts Service (CAS) que dóna accés a la major col·lecció d’informació sobre química, enginyeria química i altres matèries relacionades.

  1. SPHERE: A Planet Finder Instrument for the VLT

    NARCIS (Netherlands)

    Beuzit, J.L.; Feldt, M.; Dohlen, K.; Mouillet, D.; Puget, P.; Antichi, J.; Baudoz, P.; Boccaletti, A.; Carbillet, M.; Charton, J.; Claudi, R.; Fusco, T.; Gratton, R.; Henning, T.; Hubin, N.; Joos, F.; Kasper, M.; Langlois, M.; Moutou, C.; Pragt, J.; Rabou, P.; Saisse, M.; Schmid, H.M.; Turatto, M.; Udry, S.; Vakili, F.; Waters, R.; Wildi, F.

    2007-01-01

    Direct detection and spectral characterization of extra-solar planets is one of the most exciting but also one of the most challenging areas in modern astronomy. For its second generation instrumentation on the VLT, ESO has supported two phase A studies for a so-called Planet Finder dedicated

  2. The science case of the CHEOPS planet finder for VLT

    NARCIS (Netherlands)

    Gratton, R.; Feldt, M.; Schmid, H.M.; Brandner, W.; Hippler, S.; Neuhauser, R.; Quirrenbach, A.; Desidera, S.; Turatto, M.; Stam, D.M.; Hasinger, G.; Turner, M.J.L.

    2004-01-01

    The CHEOPS Planet Finder is one of the proposed second generation instruments for the VLT. Its purpose is to image and characterize giant extrasolar planets in different phases of their evolution: young, warm planets as well as old, cold ones. Imaging the last ones is the most challenging task

  3. Neutron halos in hypernuclei

    CERN Document Server

    Lue, H F; Meng, J; Zhou, S G

    2003-01-01

    Properties of single-LAMBDA and double-LAMBDA hypernuclei for even-N Ca isotopes ranging from the proton dripline to the neutron dripline are studied using the relativistic continuum Hartree-Bogolyubov theory with a zero-range pairing interaction. Compared with ordinary nuclei, the addition of one or two LAMBDA-hyperons lowers the Fermi level. The predicted neutron dripline nuclei are, respectively, sup 7 sup 5 subLAMBDA Ca and sup 7 sup 6 sub 2 subLAMBDA Ca, as the additional attractive force provided by the LAMBDA-N interaction shifts nuclei from outside to inside the dripline. Therefore, the last bound hypernuclei have two more neutrons than the corresponding ordinary nuclei. Based on the analysis of two-neutron separation energies, neutron single-particle energy levels, the contribution of continuum and nucleon density distribution, giant halo phenomena due to the pairing correlation, and the contribution from the continuum are suggested to exist in Ca hypernuclei similar to those that appear in ordinary ...

  4. PKI Scalability Issues

    OpenAIRE

    Slagell, Adam J.; Bonilla, Rafael

    2004-01-01

    This report surveys different PKI technologies such as PKIX and SPKI and the issues of PKI that affect scalability. Much focus is spent on certificate revocation methodologies and status verification systems such as CRLs, Delta-CRLs, CRS, Certificate Revocation Trees, Windowed Certificate Revocation, OCSP, SCVP and DVCS.

  5. Halo modelling in chameleon theories

    Energy Technology Data Exchange (ETDEWEB)

    Lombriser, Lucas; Koyama, Kazuya [Institute of Cosmology and Gravitation, University of Portsmouth, Dennis Sciama Building, Burnaby Road, Portsmouth, PO1 3FX (United Kingdom); Li, Baojiu, E-mail: lucas.lombriser@port.ac.uk, E-mail: kazuya.koyama@port.ac.uk, E-mail: baojiu.li@durham.ac.uk [Institute for Computational Cosmology, Ogden Centre for Fundamental Physics, Department of Physics, University of Durham, Science Laboratories, South Road, Durham, DH1 3LE (United Kingdom)

    2014-03-01

    We analyse modelling techniques for the large-scale structure formed in scalar-tensor theories of constant Brans-Dicke parameter which match the concordance model background expansion history and produce a chameleon suppression of the gravitational modification in high-density regions. Thereby, we use a mass and environment dependent chameleon spherical collapse model, the Sheth-Tormen halo mass function and linear halo bias, the Navarro-Frenk-White halo density profile, and the halo model. Furthermore, using the spherical collapse model, we extrapolate a chameleon mass-concentration scaling relation from a ΛCDM prescription calibrated to N-body simulations. We also provide constraints on the model parameters to ensure viability on local scales. We test our description of the halo mass function and nonlinear matter power spectrum against the respective observables extracted from large-volume and high-resolution N-body simulations in the limiting case of f(R) gravity, corresponding to a vanishing Brans-Dicke parameter. We find good agreement between the two; the halo model provides a good qualitative description of the shape of the relative enhancement of the f(R) matter power spectrum with respect to ΛCDM caused by the extra attractive gravitational force but fails to recover the correct amplitude. Introducing an effective linear power spectrum in the computation of the two-halo term to account for an underestimation of the chameleon suppression at intermediate scales in our approach, we accurately reproduce the measurements from the N-body simulations.

  6. Scalable Resolution Display Walls

    KAUST Repository

    Leigh, Jason

    2013-01-01

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

  7. Galaxy models with live halos

    CERN Document Server

    Sellwood, J A

    1980-01-01

    Computer models of galaxies are described, in which the disc stars and the halo stars are both treated fully self consistently. These were used to test the validity of the 'rigid halo' approximation usually employed when studying the instabilities of a disc of stars. The models show that very little interaction between the populations occurs while the disc remains nearly axisymmetric, but a strong bar is able to transfer angular momentum from the disc to the halo. The global bar stability of the disc is not greatly affected by the interaction between the two stellar populations, and it is found that a large fraction of the total galactic mass is still required in the spheroidal component if bar formation is to be prevented. (36 refs).

  8. Detectability of active triangulation range finder: a solar irradiance approach.

    Science.gov (United States)

    Liu, Huizhe; Gao, Jason; Bui, Viet Phuong; Liu, Zhengtong; Lee, Kenneth Eng Kian; Peh, Li-Shiuan; Png, Ching Eng

    2016-06-27

    Active triangulation range finders are widely used in a variety of applications such as robotics and assistive technologies. The power of the laser source should be carefully selected in order to satisfy detectability and still remain eye-safe. In this paper, we present a systematic approach to assess the detectability of an active triangulation range finder in an outdoor environment. For the first time, we accurately quantify the background noise of a laser system due to solar irradiance by coupling the Perez all-weather sky model and ray tracing techniques. The model is validated with measurements with a modeling error of less than 14.0%. Being highly generic and sufficiently flexible, the proposed model serves as a guide to define a laser system for any geographical location and microclimate.

  9. Col·lecció programaris: SciFinder

    OpenAIRE

    Cavaller, Víctor

    2008-01-01

    SciFinder és un programari informàtic de CAS dissenyat principalment per a l'ús per part de químics professionals d'organitzacions comercials. Existeixen versions tant per a S.O. Windows com per a Macintosh. SciFinder Scholar és la versió pensada per a universitats i altres institucions acadèmiques, en la qual no estan presents certes característiques per a recerques en diverses bases de dades simultàniament. Les dues versions han estat dissenyades amb interfícies gràfiques, i per això són es...

  10. Halo-free Phase Contrast Microscopy

    National Research Council Canada - National Science Library

    Tan H Nguyen; Mikhail Kandel; Haadi M Shakir; Catherine Best-popescu; Jyothi Arikkath; Minh N Do; Gabriel Popescu

    2017-01-01

    We present a new approach for retrieving halo-free phase contrast microscopy (hfPC) images by upgrading the conventional PC microscope with an external interferometric module, which generates sufficient data for reversing the halo artifact...

  11. The hardware track finder processor in CMS at CERN

    CERN Document Server

    Kluge, A

    1997-01-01

    The work covers the design of the Track Finder Processor in the high energy experiment CMS (Compact Muon Solenoid, planned for 2005) at CERN/Geneva. The task of this processor is to identify muons and measure their transverse momentum. The track finder processor makes it possible to determine the physical relevance of each high energetic collision and to forward only interesting data to the data an alysis units. Data of more than two hundred thousand detector cells are used to determine the location of muons and measure their transverse momentum. Each 25 ns a new data set is generated. Measurem ent of location and transverse momentum of the muons can be terminated within 350 ns by using an ASIC (Application Specific Integrated Circuit). A pipeline architecture processes new data sets with th e required data rate of 40 MHz to ensure dead time free operation. In the framework of this study specifications and the overall concept of the track finder processor were worked out in detail. Simul ations were performed...

  12. 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.

  13. Visibility of halos and rainbows.

    Science.gov (United States)

    Gedzelman, S D

    1980-09-15

    A theory for the visibility of halos and rainbows is presented. The light reaching the observer's eye from the direction of the halo or rainbow is assumed to consist of two parts: (1) a beam of singly scattered sunlight (or moonlight) from a cloud of ice crystals or a rainswath, which, in turn, has suffered depletion by scattering or absorption in its passage to the observer, and (2) the general background brightness. The model is able to account for several long-known qualitative observations concerning halos, namely, that the brightest halos are produced by optically thin cirrostratus clouds (i.e., for which the cloud optical depth tau(c), rainbow the brightness of the beam increases monotonically with the optical depth tau(R) of the sunlit part of the rainswath, but the increase is quite small for tau(R) >/=1. On the other hand, the brightness of the background increases more rapidly with tau(R) for tau(R)> 1 so that the rainbow appears most easily visible for tau(R) less, similar1. This implies that the most easily visible rainbows are produced by light or moderate showers rather than heavy downpours. Finally, suggestions are made for applying the theory to other atmospheric optical phenomena, such as coronas and glories.

  14. Halo Mitigation Using Nonlinear Lattices

    CERN Document Server

    Sonnad, Kiran G

    2005-01-01

    This work shows that halos in beams with space charge effects can be controlled by combining nonlinear focusing and collimation. The study relies on Particle-in-Cell (PIC) simulations for a one dimensional, continuous focusing model. The PIC simulation results show that nonlinear focusing leads to damping of the beam oscillations thereby reducing the mismatch. It is well established that reduced mismatch leads to reduced halo formation. However, the nonlinear damping is accompanied by emittance growth causing the beam to spread in phase space. As a result, inducing nonlinear damping alone cannot help mitigate the halo. To compensate for this expansion in phase space, the beam is collimated in the simulation and further evolution of the beam shows that the halo is not regenerated. The focusing model used in the PIC is analysed using the Lie Transform perturbation theory showing that by averaging over a lattice period, one can reuduce the focusing force to a form that is identical to that used in the PIC simula...

  15. Scalable Reliable SD Erlang Design

    OpenAIRE

    Chechina, Natalia; Trinder, Phil; Ghaffari, Amir; Green, Rickard; Lundin, Kenneth; Virding, Robert

    2014-01-01

    This technical report presents the design of Scalable Distributed (SD) Erlang: a set of language-level changes that aims to enable Distributed Erlang to scale for server applications on commodity hardware with at most 100,000 cores. We cover a number of aspects, specifically anticipated architecture, anticipated failures, scalable data structures, and scalable computation. Other two components that guided us in the design of SD Erlang are design principles and typical Erlang applications. The...

  16. RxnFinder: biochemical reaction search engines using molecular structures, molecular fragments and reaction similarity.

    Science.gov (United States)

    Hu, Qian-Nan; Deng, Zhe; Hu, Huanan; Cao, Dong-Sheng; Liang, Yi-Zeng

    2011-09-01

    Biochemical reactions play a key role to help sustain life and allow cells to grow. RxnFinder was developed to search biochemical reactions from KEGG reaction database using three search criteria: molecular structures, molecular fragments and reaction similarity. RxnFinder is helpful to get reference reactions for biosynthesis and xenobiotics metabolism. RxnFinder is freely available via: http://sdd.whu.edu.cn/rxnfinder. qnhu@whu.edu.cn.

  17. Scalable photoreactor for hydrogen production

    KAUST Repository

    Takanabe, Kazuhiro

    2017-04-06

    Provided herein are scalable photoreactors that can include a membrane-free water- splitting electrolyzer and systems that can include a plurality of membrane-free water- splitting electrolyzers. Also provided herein are methods of using the scalable photoreactors provided herein.

  18. Metrology system for the Terrestrial Planet Finder Coronagraph

    Science.gov (United States)

    Shaklin, Stuart; Marchen, Luis; Zhao, Feng; Peters, Robert D.; Ho, Tim; Holmes, Buck

    2004-01-01

    The Terrestrial Planet Finder (TPF) employs an aggressive coronagraph designed to obtain better than 1e-10 contrast inside the third Airy ring. Minute changes in low-order aberration content scatter significant light at this position. One implication is the requirement to control low-order aberrations induced by motion of the secondary mirror relative to the primary mirror; sub-nanometer relative positional stability is required. We propose a 6-beam laser truss to monitor the relative positions of the two mirrors. The truss is based on laser metrology developed for the Space Interferometry Mission.

  19. Strategies for chemical reaction searching in SciFinder

    Science.gov (United States)

    Ridley

    2000-09-01

    The bibliographic, chemical structure, and chemical reaction databases produced by Chemical Abstracts Service allow a number of possibilities for chemical reaction searching. While these same databases may be searched through the STN network, many end-users find the intuitive software interface SciFinder simpler, but there still are issues to address. Searching may be performed through keywords, chemical structures, or chemical reactions, and the answers may vary with respect to precision and comprehension. Often combinations of search options may be needed to best solve the problem. Retrosynthetic analyses are easily performed in the chemical reaction database and can give unique insights into synthetic alternatives.

  20. Design and Performance of the Terrestrial Planet Finder Coronagraph

    Science.gov (United States)

    White, Mary L.; Shaklan, Stuart; Lisman, P. Doulas; Ho, Timothy; Mouroulis, Pantazis; Basinger, Scott; Ledeboer, Bill; Kwack, Eug; Kissil, Andy; Mosier, Gary; hide

    2004-01-01

    Terrestrial Planet Finder Coronagraph, one of two potential architectures, is described. The telescope is designed to make a visible wavelength survey of the habitable zones of at least thirty stars in search of earth-like planets. The preliminary system requirements, optical parameters, mechanical and thermal design, operations scenario and predicted performance is presented. The 6-meter aperture telescope has a monolithic primary mirror, which along with the secondary tower, are being designed to meet the stringent optical tolerances of the planet-finding mission. Performance predictions include dynamic and thermal finite element analysis of the telescope optics and structure, which are used to make predictions of the optical performance of the system.

  1. Galaxy and Mass Assembly (GAMA): halo formation times and halo assembly bias on the cosmic web

    Science.gov (United States)

    Tojeiro, Rita; Eardley, Elizabeth; Peacock, John A.; Norberg, Peder; Alpaslan, Mehmet; Driver, Simon P.; Henriques, Bruno; Hopkins, Andrew M.; Kafle, Prajwal R.; Robotham, Aaron S. G.; Thomas, Peter; Tonini, Chiara; Wild, Vivienne

    2017-09-01

    We present evidence for halo assembly bias as a function of geometric environment (GE). By classifying Galaxy and Mass Assembly (GAMA) galaxy groups as residing in voids, sheets, filaments or knots using a tidal tensor method, we find that low-mass haloes that reside in knots are older than haloes of the same mass that reside in voids. This result provides direct support to theories that link strong halo tidal interactions with halo assembly times. The trend with GE is reversed at large halo mass, with haloes in knots being younger than haloes of the same mass in voids. We find a clear signal of halo downsizing - more massive haloes host galaxies that assembled their stars earlier. This overall trend holds independently of GE. We support our analysis with an in-depth exploration of the L-Galaxies semi-analytic model, used here to correlate several galaxy properties with three different definitions of halo formation time. We find a complex relationship between halo formation time and galaxy properties, with significant scatter. We confirm that stellar mass to halo mass ratio, specific star formation rate (SFR) and mass-weighed age are reasonable proxies of halo formation time, especially at low halo masses. Instantaneous SFR is a poor indicator at all halo masses. Using the same semi-analytic model, we create mock spectral observations using complex star formation and chemical enrichment histories, which approximately mimic GAMA's typical signal-to-noise ratio and wavelength range. We use these mocks to assert how well potential proxies of halo formation time may be recovered from GAMA-like spectroscopic data.

  2. Knickpoint finder: A software tool that improves neotectonic analysis

    Science.gov (United States)

    Queiroz, G. L.; Salamuni, E.; Nascimento, E. R.

    2015-03-01

    This work presents a new software tool for morphometric analysis of drainage networks based on the methods of Hack (1973) and Etchebehere et al. (2004). This tool is applicable to studies of morphotectonics and neotectonics. The software used a digital elevation model (DEM) to identify the relief breakpoints along drainage profiles (knickpoints). The program was coded in Python for use on the ArcGIS platform and is called Knickpoint Finder. A study area was selected to test and evaluate the software's ability to analyze and identify neotectonic morphostructures based on the morphology of the terrain. For an assessment of its validity, we chose an area of the James River basin, which covers most of the Piedmont area of Virginia (USA), which is an area of constant intraplate seismicity and non-orogenic active tectonics and exhibits a relatively homogeneous geodesic surface currently being altered by the seismogenic features of the region. After using the tool in the chosen area, we found that the knickpoint locations are associated with the geologic structures, epicenters of recent earthquakes, and drainages with rectilinear anomalies. The regional analysis demanded the use of a spatial representation of the data after processing using Knickpoint Finder. The results were satisfactory in terms of the correlation of dense areas of knickpoints with active lineaments and the rapidity of the identification of deformed areas. Therefore, this software tool may be considered useful in neotectonic analyses of large areas and may be applied to any area where there is DEM coverage.

  3. Accuracy evaluation of object position determination in the working area of stereo range finder

    OpenAIRE

    Samoylov, А. М.; Grenke, V. V.; Shakirov, I. V.

    2007-01-01

    The solution of problem on position determination of moving objects system in operating TV stereo range finder has been shown. The technique of accuracy evaluation in determining their position is described. The results of the method application on the TV stereo range finder model are presented.

  4. PathogenFinder - Distinguishing Friend from Foe Using Bacterial Whole Genome Sequence Data

    DEFF Research Database (Denmark)

    Cosentino, Salvatore; Larsen, Mette Voldby; Aarestrup, Frank Møller

    2013-01-01

    approaches. We describe PathogenFinder (http://cge.cbs.dtu.dk/services/PathogenFinder/), a web-server for the prediction of bacterial pathogenicity by analysing the input proteome, genome, or raw reads provided by the user. The method relies on groups of proteins, created without regard to their annotated...

  5. Realistic simulation of laser range finder behavior in a smoky environment

    NARCIS (Netherlands)

    Formsma, O.; Dijkshoorn, N.; van Noort, S.; Visser, A.; Ruiz-del-Solar, J.; Chown, E.; Plöger, P.G.

    2011-01-01

    The Urban Search and Rescue Simulation used for RoboCup lacks realistic response of laser range finders on smoke. In this paper, the behavior of a Hokuyo and Sick laser range finder in a smoky environment is studied. The behavior of the lasers is among others a function of the visibility level, and

  6. Scalable Frequent Subgraph Mining

    KAUST Repository

    Abdelhamid, Ehab

    2017-06-19

    A graph is a data structure that contains a set of nodes and a set of edges connecting these nodes. Nodes represent objects while edges model relationships among these objects. Graphs are used in various domains due to their ability to model complex relations among several objects. Given an input graph, the Frequent Subgraph Mining (FSM) task finds all subgraphs with frequencies exceeding a given threshold. FSM is crucial for graph analysis, and it is an essential building block in a variety of applications, such as graph clustering and indexing. FSM is computationally expensive, and its existing solutions are extremely slow. Consequently, these solutions are incapable of mining modern large graphs. This slowness is caused by the underlying approaches of these solutions which require finding and storing an excessive amount of subgraph matches. This dissertation proposes a scalable solution for FSM that avoids the limitations of previous work. This solution is composed of four components. The first component is a single-threaded technique which, for each candidate subgraph, needs to find only a minimal number of matches. The second component is a scalable parallel FSM technique that utilizes a novel two-phase approach. The first phase quickly builds an approximate search space, which is then used by the second phase to optimize and balance the workload of the FSM task. The third component focuses on accelerating frequency evaluation, which is a critical step in FSM. To do so, a machine learning model is employed to predict the type of each graph node, and accordingly, an optimized method is selected to evaluate that node. The fourth component focuses on mining dynamic graphs, such as social networks. To this end, an incremental index is maintained during the dynamic updates. Only this index is processed and updated for the majority of graph updates. Consequently, search space is significantly pruned and efficiency is improved. The empirical evaluation shows that the

  7. Scalable Nanomanufacturing—A Review

    Directory of Open Access Journals (Sweden)

    Khershed Cooper

    2017-01-01

    Full Text Available This article describes the field of scalable nanomanufacturing, its importance and need, its research activities and achievements. The National Science Foundation is taking a leading role in fostering basic research in scalable nanomanufacturing (SNM. From this effort several novel nanomanufacturing approaches have been proposed, studied and demonstrated, including scalable nanopatterning. This paper will discuss SNM research areas in materials, processes and applications, scale-up methods with project examples, and manufacturing challenges that need to be addressed to move nanotechnology discoveries closer to the marketplace.

  8. The ContactFinder agent: Answering bulletin board questions with referrals

    Energy Technology Data Exchange (ETDEWEB)

    Krulwich, B.; Burkey, C. [Center for Strategic Technology Research, Northbrook, IL (United States)

    1996-12-31

    ContactFinder is an intelligent agent whose approach to assisting users is valuable and innovative in the following four ways. First, ContactFinder operates proactively in reading and responding to messages on electronic bulletin boards rather than acting in response to user queries. Second, ContactFinder assists users by referring them to other people who can help them, rather than attempting to find information that directly answers the user`s specific question. Third, ContactFinder categorizes messages and extracts their topic areas using a set of heuristics that are very efficient and demonstrably highly effective. Fourth, ContactFinder posts its referrals back to the bulletin boards rather than simply communicating with specific users, to increase the information density and connectivity of the system. This paper discusses these aspects of the system and demonstrates their effectiveness in over six months of use on a large-scale internal bulletin board.

  9. Unbound particles in dark matter halos

    Energy Technology Data Exchange (ETDEWEB)

    Behroozi, Peter S.; Loeb, Abraham; Wechsler, Risa H.

    2013-06-13

    We investigate unbound dark matter particles in halos by tracing particle trajectories in a simulation run to the far future (a = 100). We find that the traditional sum of kinetic and potential energies is a very poor predictor of which dark matter particles will eventually become unbound from halos. We also study the mass fraction of unbound particles, which increases strongly towards the edges of halos, and decreases significantly at higher redshifts. We discuss implications for dark matter detection experiments, precision calibrations of the halo mass function, the use of baryon fractions to constrain dark energy, and searches for intergalactic supernovae.

  10. Halo scale predictions of symmetron modified gravity

    Energy Technology Data Exchange (ETDEWEB)

    Clampitt, Joseph; Jain, Bhuvnesh; Khoury, Justin, E-mail: clampitt@sas.upenn.edu, E-mail: bjain@physics.upenn.edu, E-mail: jkhoury@sas.upenn.edu [Center for Particle Cosmology and Department of Physics and Astronomy, University of Pennsylvania, 209 South 33rd St., Philadelphia, PA 19104 (United States)

    2012-01-01

    We offer predictions of symmetron modified gravity in the neighborhood of realistic dark matter halos. The predictions for the fifth force are obtained by solving the nonlinear symmetron equation of motion in the spherical NFW approximation. In addition, we compare the three major known screening mechanisms: Vainshtein, Chameleon, and Symmetron around such dark matter halos, emphasizing the significant differences between them and highlighting observational tests which exploit these differences. Finally, we demonstrate the host halo environmental screening effect (''blanket screening'') on smaller satellite halos by solving for the modified forces around a density profile which is the sum of satellite and approximate host components.

  11. Labelling HaloTag Fusion Proteins with HaloTag Ligand in Living Cells.

    Science.gov (United States)

    Duc, Huy Nguyen; Ren, Xiaojun

    2017-09-05

    HaloTag has been widely used to label proteins in vitro and in vivo (Los et al., 2008). In this protocol, we describe labelling HaloTag-Cbx fusion proteins by HaloTag ligands for live-cell single-molecule imaging (Zhen et al., 2016).

  12. Labelling HaloTag Fusion Proteins with HaloTag Ligand in Living Cells

    OpenAIRE

    Duc, Huy Nguyen; Ren, Xiaojun

    2017-01-01

    HaloTag has been widely used to label proteins in vitro and in vivo (Los et al., 2008). In this protocol, we describe labelling HaloTag-Cbx fusion proteins by HaloTag ligands for live-cell single-molecule imaging (Zhen et al., 2016).

  13. Scalable Gravity Offload System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A scalable gravity offload device simulates reduced gravity for the testing of various surface system elements such as mobile robots, excavators, habitats, and...

  14. UARS Halogen Occultation Experiment (HALOE) Level 2 V001

    Data.gov (United States)

    National Aeronautics and Space Administration — The HALOE home page on the WWW is http://haloe.gats-inc.com/home/index.php The Halogen Occultation Experiment (HALOE) on NASA's Upper Atmosphere Research Satellite...

  15. Design for a source-agile automatic direction finder (ADF)

    Science.gov (United States)

    Myler, Harley

    2015-05-01

    The design is intended for aircraft although any vehicle or even a man-mobile system could use the concept. An automatically reconfigurable antenna using MEMS RF switches is driven to seek signals consistent with the current location of the system. The antenna feeds a Software Defined Radio (SDR) that scans for signals and when a signal is found, it is identified and then the azimuth to the signal is used, along with a signal strength parameter, to confirm the location of the system. This is an extension of the now obsolete Automatic Direction Finder (ADF) aircraft navigation tool that used AM broadcast non-directional beacons (NDB), many of which are still in service. The current system can access any radio signal within the limits of the reconfigurable antenna and the SDR.

  16. In campus location finder using mobile application services

    Science.gov (United States)

    Fai, Low Weng; Audah, Lukman

    2017-09-01

    Navigation services become very common in this era, the application include Google Map, Waze and etc. Although navigation application contains the main routing service in open area but not all of the buildings are recorded in the database. In this project, an application is made for the indoor and outdoor navigation in Universiti Tun Hussein Onn Malaysia (UTHM). It is used to help outsider and new incoming students by navigating them from their current location to destination using mobile application name "U Finder". Thunkable website has been used to build the application for outdoor and indoor navigation. Outdoor navigation is linked to the Google Map and indoor navigation is using the QR code for positioning and routing picture for navigation. The outdoor navigation can route user to the main faculties in UTHM and indoor navigation is only done for the G1 building in UTHM.

  17. Terrestrial Planet Finder Coronagraph : technology and mission design studies

    Science.gov (United States)

    Ford, Virginia G.

    2004-01-01

    The Terrestrial Planet Finder (TPF) coronagraph study involves exploring the technologies that enable a coronagraph style instrument to image and characterize earth-like planets orbiting nearby stars. Testbeds have been developed to demonstrate the emerging technologies needed for this effort and an architecture study has resulted in designs of a facility that will provide the environment needed for the technology to function in this role. A broad community of participants is involved in this work through studies, analyses, fabrication of components, and participation in the design effort. The scope of activities - both on the technology side and in the architecture study side - will be presented in this paper. The status and the future plans of the activities will be reviewed.

  18. Studying dark matter haloes with weak lensing

    NARCIS (Netherlands)

    Velander, Malin Barbro Margareta

    2012-01-01

    Our Universe is comprised not only of normal matter but also of unknown components: dark matter and dark energy. This Thesis recounts studies of dark matter haloes, using a technique known as weak gravitational lensing, in order to learn more about the nature of these dark components. The haloes

  19. Halo abundances and shear in void models

    DEFF Research Database (Denmark)

    Alonso, David; García-Bellido, Juan; Haugbølle, Troels

    2012-01-01

    We study the non-linear gravitational collapse of dark matter into halos through numerical N-body simulations of Lemaitre-Tolman-Bondi void models. We extend the halo mass function formalism to these models in a consistent way. This extension not only compares well with the simulated data at all...

  20. Analytical halo model of galactic conformity

    Science.gov (United States)

    Pahwa, Isha; Paranjape, Aseem

    2017-09-01

    We present a fully analytical halo model of colour-dependent clustering that incorporates the effects of galactic conformity in a halo occupation distribution framework. The model, based on our previous numerical work, describes conformity through a correlation between the colour of a galaxy and the concentration of its parent halo, leading to a correlation between central and satellite galaxy colours at fixed halo mass. The strength of the correlation is set by a tunable 'group quenching efficiency', and the model can separately describe group-level correlations between galaxy colour (1-halo conformity) and large-scale correlations induced by assembly bias (2-halo conformity). We validate our analytical results using clustering measurements in mock galaxy catalogues, finding that the model is accurate at the 10-20 per cent level for a wide range of luminosities and length-scales. We apply the formalism to interpret the colour-dependent clustering of galaxies in the Sloan Digital Sky Survey (SDSS). We find good overall agreement between the data and a model that has 1-halo conformity at a level consistent with previous results based on an SDSS group catalogue, although the clustering data require satellites to be redder than suggested by the group catalogue. Within our modelling uncertainties, however, we do not find strong evidence of 2-halo conformity driven by assembly bias in SDSS clustering.

  1. MODIFIED DYNAMICS (MOND) AS A DARK HALO

    NARCIS (Netherlands)

    SANDERS, RH; BEGEMAN, KG

    1994-01-01

    We propose a form for dark haloes that embodies the fundamental aspect of Milgrom's modified dynamics (MOND): the discrepancy between the visible mass and the Newtonian dynamical mass appears below a critical acceleration. This is a halo having a density distribution, at least to several tens of

  2. Galactic stellar haloes in the CDM model

    NARCIS (Netherlands)

    Cooper, A. P.; Cole, S.; Frenk, C. S.; White, S. D. M.; Helly, J.; Benson, A. J.; De Lucia, G.; Helmi, A.; Jenkins, A.; Navarro, J. F.; Springel, V.; Wang, J.

    2010-01-01

    We present six simulations of galactic stellar haloes formed by the tidal disruption of accreted dwarf galaxies in a fully cosmological setting. Our model is based on the Aquarius project, a suite of high-resolution N-body simulations of individual dark matter haloes. We tag subsets of particles in

  3. WFIRST: Surveying galactic halos within 10Mpc

    Science.gov (United States)

    Courtney, Sol; Johnston, Kathryn; Sanderson, Robyn; WINGS Team

    2018-01-01

    Three aims of a WFIRST Infrared Nearby Galaxy Survey (WINGS) of stellar halos are: (i) to look at the global properties of the halos (e.g. radial profile and total content); (ii) to find and interpret structures that are signatures of accretion histories (including luminosity functions, merger rates and orbits); (iii) to find features at widest possible separations in order to constrain the distribution of dark matter. For all of the above purposes, the halos should be observed to the greatest radial extent possible. The extent to which this is possible or interesting will depend on expected densities of the stellar halos as well as contamination by background galaxies at faint magnitudes. This study “observes" the Bullock/Johnston stellar halo models as a guide for these expectations.

  4. In Silico Detection and Typing of Plasmids using PlasmidFinder and Plasmid Multilocus Sequence Typing

    DEFF Research Database (Denmark)

    Carattoli, Alessandra; Zankari, Ea; García-Fernández, Aurora

    2014-01-01

    into a Web tool called PlasmidFinder that can be used for replicon sequence analysis of raw, contig group, or completely assembled and closed plasmid sequencing data. The PlasmidFinder database currently consists of 116 replicon sequences that match with at least at 80% nucleotide identity all replicon...... of Salmonella enterica serovar Typhimurium isolates. PlasmidFinder identified a total of 103 replicons and between zero and five different plasmid replicons within each of 49 S. Typhimurium draft genomes tested. The pMLST Web tool was able to subtype genomic sequencing data of plasmids, revealing both known...

  5. Halo assembly bias and the tidal anisotropy of the local halo environment

    Science.gov (United States)

    Paranjape, Aseem; Hahn, Oliver; Sheth, Ravi K.

    2018-02-01

    We study the role of the local tidal environment in determining the assembly bias of dark matter haloes. Previous results suggest that the anisotropy of a halo's environment (i.e, whether it lies in a filament or in a more isotropic region) can play a significant role in determining the eventual mass and age of the halo. We statistically isolate this effect using correlations between the large-scale and small-scale environments of simulated haloes at z = 0 with masses between 1011.6 ≲ (m/h-1M⊙) ≲ 1014.9. We probe the large-scale environment using a novel halo-by-halo estimator of linear bias. For the small-scale environment, we identify a variable αR that captures the tidal anisotropy in a region of radius R = 4R200b around the halo and correlates strongly with halo bias at fixed mass. Segregating haloes by αR reveals two distinct populations. Haloes in highly isotropic local environments (αR ≲ 0.2) behave as expected from the simplest, spherically averaged analytical models of structure formation, showing a negative correlation between their concentration and large-scale bias at all masses. In contrast, haloes in anisotropic, filament-like environments (αR ≳ 0.5) tend to show a positive correlation between bias and concentration at any mass. Our multi-scale analysis cleanly demonstrates how the overall assembly bias trend across halo mass emerges as an average over these different halo populations, and provides valuable insights towards building analytical models that correctly incorporate assembly bias. We also discuss potential implications for the nature and detectability of galaxy assembly bias.

  6. Scalable algorithms for contact problems

    CERN Document Server

    Dostál, Zdeněk; Sadowská, Marie; Vondrák, Vít

    2016-01-01

    This book presents a comprehensive and self-contained treatment of the authors’ newly developed scalable algorithms for the solutions of multibody contact problems of linear elasticity. The brand new feature of these algorithms is theoretically supported numerical scalability and parallel scalability demonstrated on problems discretized by billions of degrees of freedom. The theory supports solving multibody frictionless contact problems, contact problems with possibly orthotropic Tresca’s friction, and transient contact problems. It covers BEM discretization, jumping coefficients, floating bodies, mortar non-penetration conditions, etc. The exposition is divided into four parts, the first of which reviews appropriate facets of linear algebra, optimization, and analysis. The most important algorithms and optimality results are presented in the third part of the volume. The presentation is complete, including continuous formulation, discretization, decomposition, optimality results, and numerical experimen...

  7. Dark matter haloes: a multistream view

    Science.gov (United States)

    Ramachandra, Nesar S.; Shandarin, Sergei F.

    2017-09-01

    Mysterious dark matter constitutes about 85 per cent of all masses in the Universe. Clustering of dark matter plays a dominant role in the formation of all observed structures on scales from a fraction to a few hundreds of Mega-parsecs. Galaxies play a role of lights illuminating these structures so they can be observed. The observations in the last several decades have unveiled opulent geometry of these structures currently known as the cosmic web. Haloes are the highest concentrations of dark matter and host luminous galaxies. Currently the most accurate modelling of dark matter haloes is achieved in cosmological N-body simulations. Identifying the haloes from the distribution of particles in N-body simulations is one of the problems attracting both considerable interest and efforts. We propose a novel framework for detecting potential dark matter haloes using the field unique for dark matter-multistream field. The multistream field emerges at the non-linear stage of the growth of perturbations because the dark matter is collisionless. Counting the number of velocity streams in gravitational collapses supplements our knowledge of spatial clustering. We assume that the virialized haloes have convex boundaries. Closed and convex regions of the multistream field are hence isolated by imposing a positivity condition on all three eigenvalues of the Hessian estimated on the smoothed multistream field. In a single-scale analysis of high multistream field resolution and low softening length, the halo substructures with local multistream maxima are isolated as individual halo sites.

  8. Effective field theory description of halo nuclei

    Science.gov (United States)

    Hammer, H.-W.; Ji, C.; Phillips, D. R.

    2017-10-01

    Nuclear halos emerge as new degrees of freedom near the neutron and proton driplines. They consist of a core and one or a few nucleons which spend most of their time in the classically-forbidden region outside the range of the interaction. Individual nucleons inside the core are thus unresolved in the halo configuration, and the low-energy effective interactions are short-range forces between the core and the valence nucleons. Similar phenomena occur in clusters of 4He atoms, cold atomic gases near a Feshbach resonance, and some exotic hadrons. In these weakly-bound quantum systems universal scaling laws for s-wave binding emerge that are independent of the details of the interaction. Effective field theory (EFT) exposes these correlations and permits the calculation of non-universal corrections to them due to short-distance effects, as well as the extension of these ideas to systems involving the Coulomb interaction and/or binding in higher angular-momentum channels. Halo nuclei exhibit all these features. Halo EFT, the EFT for halo nuclei, has been used to compute the properties of single-neutron, two-neutron, and single-proton halos of s-wave and p-wave type. This review summarizes these results for halo binding energies, radii, Coulomb dissociation, and radiative capture, as well as the connection of these properties to scattering parameters, thereby elucidating the universal correlations between all these observables. We also discuss how Halo EFT's encoding of the long-distance physics of halo nuclei can be used to check and extend ab initio calculations that include detailed modeling of their short-distance dynamics.

  9. The effect of vortex finder heights on separation efficiency of dust cyclone

    Directory of Open Access Journals (Sweden)

    Suthin Pholboorn

    2016-06-01

    Full Text Available The effect of vortex finder heights on separation efficiency of dust cyclone has been experimentally investigated in this present study. The separation efficiency of three cyclones with different vortex finder heights was measured as a function of particle size of dust and velocity of air. Husk ash was used as dust particles in the air. Three values of vortex finder heights of cyclone including 30, 50 and 70 mm were investigated. The inlet velocities of air were varied from 6.61, 7.35, 8.06 to 8.81 m/s. The dimensions of husk ash were conducted into four ranges, 0-150, 150-250, 250-500 and 500-850 micro meters. The experimented result reveals that the separation efficiency of dust cyclone was increased when the particle size of husk ash and the air velocity were increased for all of vortex finder heights. The vortex finder height of 50 mm was observed to have more separation efficiency than the others for all air velocities and particle sizes. The maximum separation efficiencies at the vortex finder height of 50 mm and the velocity of 8.81 m/s for all aforementioned particle ranges were found 98.85, 99.51, 99.69 and 99.91 percentages, respectively.

  10. Degradation of HaloTag-fused nuclear proteins using bestatin-HaloTag ligand hybrid molecules.

    Science.gov (United States)

    Tomoshige, Shusuke; Naito, Mikihiko; Hashimoto, Yuichi; Ishikawa, Minoru

    2015-10-14

    We have developed a protein knockdown technology using hybrid small molecules designed as conjugates of a ligand for the target protein and a ligand for ubiquitin ligase cellular inhibitor of apoptosis protein 1 (cIAP1). However, this technology has several limitations. Here, we report the development of a novel protein knockdown system to address these limitations. In this system, target proteins are fused with HaloTag to provide a common binding site for a degradation inducer. We designed and synthesized small molecules consisting of alkyl chloride as the HaloTag-binding degradation inducer, which binds to HaloTag, linked to BE04 (2), which binds to cIAP1. Using this system, we successfully knocked down HaloTag-fused cAMP responsive element binding protein 1 (HaloTag-CREB1) and HaloTag-fused c-jun (HaloTag-c-jun), which are ligand-unknown nuclear proteins, in living cells. HaloTag-binding degradation inducers can be synthesized easily, and are expected to be useful as biological tools for pan-degradation of HaloTag-fused proteins.

  11. Planet Detection Algorithms for the Terrestrial Planet Finder-C

    Science.gov (United States)

    Kasdin, N. J.; Braems, I.

    2005-12-01

    Critical to mission planning for the terrestrial planet finder coronagraph (TPF-C) is the ability to estimate integration times for planet detection. This detection is complicated by the presence of background noise due to local and exo-zodiacal dust, by residual speckle due optical errors, and by the dependence of the PSF shape on the specific coronagraph. In this paper we examine in detail the use of PSF fitting (matched filtering) for planet detection, derive probabilistic bounds for the signal-to-noise ratio by balancing missed detection and false alarm rates, and demonstrate that this is close to the optimal linear detection technique. We then compare to a Bayesian detection approach and show that for very low background the Bayesian method offers integration time improvements, but rapidly approaches the PSF fitting result for reasonable levels of background noise. We confirm via monte-carlo simulations. This work was supported under a grant from the Jet Propulsion Laboratory and by a fellowship from the Institut National de Recherche en Informatique et Automatique (INRIA).

  12. APF—The Lick Observatory Automated Planet Finder

    Science.gov (United States)

    Vogt, Steven S.; Radovan, Matthew; Kibrick, Robert; Butler, R. Paul; Alcott, Barry; Allen, Steve; Arriagada, Pamela; Bolte, Mike; Burt, Jennifer; Cabak, Jerry; Chloros, Kostas; Cowley, David; Deich, William; Dupraw, Brian; Earthman, Wayne; Epps, Harland; Faber, Sandra; Fischer, Debra; Gates, Elinor; Hilyard, David; Holden, Brad; Johnston, Ken; Keiser, Sandy; Kanto, Dick; Katsuki, Myra; Laiterman, Lee; Lanclos, Kyle; Laughlin, Greg; Lewis, Jeff; Lockwood, Chris; Lynam, Paul; Marcy, Geoffrey; McLean, Maureen; Miller, Joe; Misch, Tony; Peck, Michael; Pfister, Terry; Phillips, Andrew; Rivera, Eugenio; Sandford, Dale; Saylor, Mike; Stover, Richard; Thompson, Matthew; Walp, Bernie; Ward, James; Wareham, John; Wei, Mingzhi; Wright, Chris

    2014-04-01

    The Automated Planet Finder (APF) is a facility purpose-built for the discovery and characterization of extrasolar planets through high-cadence Doppler velocimetry of the reflex barycentric accelerations of their host stars. Located atop Mt. Hamilton, the APF facility consists of a 2.4-m telescope and its Levy spectrometer, an optical echelle spectrometer optimized for precision Doppler velocimetry. APF features a fixed format spectral range from 374 nm - 970 nm, and delivers a "Throughput" (resolution * slit width product) of 114,000 arc-seconds, with spectral resolutions up to 150,000. Overall system efficiency (fraction of photons incident on the primary mirror that are detected by the science CCD) on blaze at 560 nm in planet-hunting mode is 15%. First-light tests on the RV standard stars HD 185144 and HD 9407 demonstrate sub-meter per second precision (RMS per observation) held over a 3-month period. This paper reviews the basic features of the telescope, dome, and spectrometer, and gives a brief summary of first-light performance.

  13. Real-Time Video Convolutional Face Finder on Embedded Platforms

    Directory of Open Access Journals (Sweden)

    Mamalet Franck

    2007-01-01

    Full Text Available A high-level optimization methodology is applied for implementing the well-known convolutional face finder (CFF algorithm for real-time applications on mobile phones, such as teleconferencing, advanced user interfaces, image indexing, and security access control. CFF is based on a feature extraction and classification technique which consists of a pipeline of convolutions and subsampling operations. The design of embedded systems requires a good trade-off between performance and code size due to the limited amount of available resources. The followed methodology copes with the main drawbacks of the original implementation of CFF such as floating-point computation and memory allocation, in order to allow parallelism exploitation and perform algorithm optimizations. Experimental results show that our embedded face detection system can accurately locate faces with less computational load and memory cost. It runs on a 275 MHz Starcore DSP at 35 QCIF images/s with state-of-the-art detection rates and very low false alarm rates.

  14. 4D Cellular Automaton Track Finder in the CBM Experiment

    Science.gov (United States)

    Akishina, Valentina; Kisel, Ivan

    2016-11-01

    The CBM experiment (FAIR/GSI, Darmstadt, Germany) will focus on the measurement of rare probes at interaction rates up to 10MHz with data flow of up to 1 TB/s. It requires a novel read-out and data-acquisition concept with self-triggered electronics and free-streaming data. In this case resolving different collisions is a non-trivial task and event building must be performed in software online. That requires full online event reconstruction and selection not only in space, but also in time, so-called 4D event building and selection. This is a task of the First-Level Event Selection (FLES). The FLES reconstruction and selection package consists of several modules: track finding, track fitting, short-lived particles finding, event building and event selection. The Cellular Automaton (CA) track finder algorithm was adapted towards time-based reconstruction. In this article, we describe in detail the modification done to the algorithm, as well as the performance of the developed time-based CA approach.

  15. Scalable shared-memory multiprocessing

    CERN Document Server

    Lenoski, Daniel E

    1995-01-01

    Dr. Lenoski and Dr. Weber have experience with leading-edge research and practical issues involved in implementing large-scale parallel systems. They were key contributors to the architecture and design of the DASH multiprocessor. Currently, they are involved with commercializing scalable shared-memory technology.

  16. Scalability study of solid xenon

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, J.; Cease, H.; Jaskierny, W. F.; Markley, D.; Pahlka, R. B.; Balakishiyeva, D.; Saab, T.; Filipenko, M.

    2015-04-01

    We report a demonstration of the scalability of optically transparent xenon in the solid phase for use as a particle detector above a kilogram scale. We employed a cryostat cooled by liquid nitrogen combined with a xenon purification and chiller system. A modified {\\it Bridgeman's technique} reproduces a large scale optically transparent solid xenon.

  17. The Dark Halo of the Milky Way

    National Research Council Canada - National Science Library

    Charles Alcock

    2000-01-01

    .... This dark matter is distributed in space differently than the stars, forming a vast, diffuse halo, more spherical than disklike, which occupies more than 1000 times the volume of the disk of stars...

  18. Exact Relativistic Magnetized Haloes around Rotating Disks

    Directory of Open Access Journals (Sweden)

    Antonio C. Gutiérrez-Piñeres

    2015-01-01

    Full Text Available The study of the dynamics of magnetic fields in galaxies is one of important problems in formation and evolution of galaxies. In this paper, we present the exact relativistic treatment of a rotating disk surrounded by a magnetized material halo. The features of the halo and disk are described by the distributional energy-momentum tensor of a general fluid in canonical form. All the relevant quantities and the metric and electromagnetic potentials are exactly determined by an arbitrary harmonic function only. For instance, the generalized Kuzmin-disk potential is used. The particular class of solutions obtained is asymptotically flat and satisfies all the energy conditions. Moreover, the motion of a charged particle on the halo is described. As far as we know, this is the first relativistic model describing analytically the magnetized halo of a rotating disk.

  19. Simulating rainbows and halos in color.

    Science.gov (United States)

    Gedzelman, S D

    1994-07-20

    Geometric optics rainbows and ice-crystal halos that include some effects of a Rayleigh-scattering atmosphere and a cloud of finite optical thickness are simulated in color by the use of a Monte Carlo approach.

  20. Spatial Clustering of Dark Matter Haloes: Secondary Bias, Neighbour Bias, and the Influence of Massive Neighbours on Halo Properties

    Science.gov (United States)

    Salcedo, Andrés N.; Maller, Ariyeh H.; Berlind, Andreas A.; Sinha, Manodeep; McBride, Cameron K.; Behroozi, Peter S.; Wechsler, Risa H.; Weinberg, David H.

    2018-01-01

    We explore the phenomenon commonly known as halo assembly bias, whereby dark matter haloes of the same mass are found to be more or less clustered when a second halo property is considered, for haloes in the mass range 3.7 × 1011 h-1 M⊙ - 5.0 × 1013 h-1 M⊙. Using the Large Suite of Dark Matter Simulations (LasDamas) we consider nine commonly used halo properties and find that a clustering bias exists if haloes are binned by mass or by any other halo property. This secondary bias implies that no single halo property encompasses all the spatial clustering information of the halo population. The mean values of some halo properties depend on their halo's distance to a more massive neighbour. Halo samples selected by having high values of one of these properties therefore inherit a neighbour bias such that they are much more likely to be close to a much more massive neighbour. This neighbour bias largely accounts for the secondary bias seen in haloes binned by mass and split by concentration or age. However, haloes binned by other mass-like properties still show a secondary bias even when the neighbour bias is removed. The secondary bias of haloes selected by their spin behaves differently than that for other halo properties, suggesting that the origin of the spin bias is different than of other secondary biases.

  1. MODIFIED GRAVITY SPINS UP GALACTIC HALOS

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jounghun [Astronomy Program, Department of Physics and Astronomy, FPRD, Seoul National University, Seoul 151-747 (Korea, Republic of); Zhao, Gong-Bo [National Astronomy Observatories, Chinese Academy of Science, Beijing 100012 (China); Li, Baojiu [Institute of Computational Cosmology, Department of Physics, Durham University, Durham DH1 3LE (United Kingdom); Koyama, Kazuya, E-mail: jounghun@astro.snu.ac.kr [Institute of Cosmology and Gravitation, University of Portsmouth, Portsmouth, PO1 3FX (United Kingdom)

    2013-01-20

    We investigate the effect of modified gravity on the specific angular momentum of galactic halos by analyzing the halo catalogs at z = 0 from high-resolution N-body simulations for a f(R) gravity model that meets the solar-system constraint. It is shown that the galactic halos in the f(R) gravity model tend to acquire significantly higher specific angular momentum than those in the standard {Lambda}CDM model. The largest difference in the specific angular momentum distribution between these two models occurs for the case of isolated galactic halos with mass less than 10{sup 11} h {sup -1} M {sub Sun }, which are likely least shielded by the chameleon screening mechanism. As the specific angular momentum of galactic halos is rather insensitive to other cosmological parameters, it can in principle be an independent discriminator of modified gravity. We speculate a possibility of using the relative abundance of low surface brightness galaxies (LSBGs) as a test of general relativity given that the formation of the LSBGs occurs in fast spinning dark halos.

  2. Nanomechanics of HaloTag tethers.

    Science.gov (United States)

    Popa, Ionel; Berkovich, Ronen; Alegre-Cebollada, Jorge; Badilla, Carmen L; Rivas-Pardo, Jaime Andrés; Taniguchi, Yukinori; Kawakami, Masaru; Fernandez, Julio M

    2013-08-28

    The active site of the Haloalkane Dehydrogenase (HaloTag) enzyme can be covalently attached to a chloroalkane ligand providing a mechanically strong tether, resistant to large pulling forces. Here we demonstrate the covalent tethering of protein L and I27 polyproteins between an atomic force microscopy (AFM) cantilever and a glass surface using HaloTag anchoring at one end and thiol chemistry at the other end. Covalent tethering is unambiguously confirmed by the observation of full length polyprotein unfolding, combined with high detachment forces that range up to ∼2000 pN. We use these covalently anchored polyproteins to study the remarkable mechanical properties of HaloTag proteins. We show that the force that triggers unfolding of the HaloTag protein exhibits a 4-fold increase, from 131 to 491 pN, when the direction of the applied force is changed from the C-terminus to the N-terminus. Force-clamp experiments reveal that unfolding of the HaloTag protein is twice as sensitive to pulling force compared to protein L and refolds at a slower rate. We show how these properties allow for the long-term observation of protein folding-unfolding cycles at high forces, without interference from the HaloTag tether.

  3. New views of the distant stellar halo

    Science.gov (United States)

    Sanderson, Robyn E.; Secunda, Amy; Johnston, Kathryn V.; Bochanski, John J.

    2017-10-01

    Currently, only a small number of Milky Way (MW) stars are known to exist beyond 100 kpc from the Galactic Centre. Though the distribution of these stars in the outer halo is believed to be sparse, they can provide evidence of more recent accretion events than in the inner halo and help map out the MW's dark matter halo to its virial radius. We have re-examined the outermost regions of 11 existing stellar halo models with two synthetic surveys: one mimicking present-day searches for distant M giants and another mimicking RR Lyra (RRL) projections for the Large Synoptic Survey Telescope (LSST). Our models suggest that colour and proper motion cuts currently used to select M giant candidates for follow-up successfully remove nearly all self-contamination from foreground halo dwarf stars and are useful for focusing observations on distant M giants, of which there are thousands to tens of thousands beyond 100 kpc in our models. We likewise expect that LSST will identify comparable numbers of RRLe at these distances. We demonstrate that several observable properties of both tracers, such as proximity of neighbouring stars, proper motions and distances (for RRLe), could help us separate different accreted dwarf galaxies from one another in the distant MW halo. We also discuss prospects for using ratios of M giants to RRLe as a proxy for accretion time, which in the future could provide new constraints on the recent accretion history of our Galaxy.

  4. RR Lyrae to understand the Galactic halo

    Science.gov (United States)

    Fiorentino, Giuliana

    2016-08-01

    We present recent results obtained using old variable RR Lyrae stars on the Galactic halo structure and its connection with nearby dwarf galaxies. We compare the period and period-amplitude distributions for a sizeable sample of fundamental mode RR Lyrae stars (RRab) in dwarf spheroidals (~1300 stars) with those in the Galactic halo (~16'000 stars) and globular clusters (~1000 stars). RRab in dwarfs -as observed today- do not appear to follow the pulsation properties shown by those in the Galactic halo, nor they have the same properties as RRab in globulars. Thanks to the OGLE experiment we extended our comparison to massive metal-rich satellites like the dwarf irregular Large Magellanic Cloud (LMC) and the Sagittarius (Sgr) dwarf spheroidal. These massive and more metal-rich stellar systems likely have contributed to the Galactic halo formation more than classical dwarf spheroidals. Finally, exploiting the intrinsic nature of RR Lyrae as distance indicators we were able to study the period and period amplitude distributions of RRab within the Halo. It turned out that the inner and the outer Halo do show a difference that may suggest a different formation scenario (in situ vs accreted).

  5. Statistics of dark matter substructure - III. Halo-to-halo variance

    Science.gov (United States)

    Jiang, Fangzhou; van den Bosch, Frank C.

    2017-11-01

    We present a study of unprecedented statistical power regarding the halo-to-halo variance of dark matter substructure. Combining N-body simulations and a semi-analytical model, we investigate the variance in subhalo mass fractions and occupation numbers, with an emphasis on their halo-formation-time dependence. We show that the average subhalo mass fraction, fsub, is mainly a function of halo formation time: at fixed formation redshift, the average subhalo mass fraction is virtually independent of halo mass and the mass dependence of fsub therefore mainly manifests the later assembly of more massive haloes. We note that the observational constraints on fsub from gravitational lensing are substantially higher than the median Λcold dark matter predictions, yet marginally lie within the 95th percentile when the halo-to-halo variance is considered. The halo occupation number distribution of subhaloes, P(Nsub|Mhalo), in addition to the well-known super-Poissonity for large 〈Nsub〉, is sub-Poissonian for 〈Nsub〉 ≲ 2. Ignoring this results in systematic errors of the predicted clustering of galaxies of a few percent, with a complicated scale- and luminosity dependence. The non-Poissonity is likely imprinted at accretion, and the dynamical evolution of subhaloes drives the statistics towards Poissonian. Contrary to a recent claim, the non-Poissonity of subhalo occupation statistics does not vanish by selecting haloes with fixed mass and fixed formation redshift. Finally, we use subhalo occupation statistics to put loose constraints on the mass and formation redshift of the Milky Way halo.

  6. Simulating Halos with the Caterpillar Project

    Science.gov (United States)

    Kohler, Susanna

    2016-04-01

    The Caterpillar Project is a beautiful series of high-resolution cosmological simulations. The goal of this project is to examine the evolution of dark-matter halos like the Milky Ways, to learn about how galaxies like ours formed. This immense computational project is still in progress, but the Caterpillar team is already providing a look at some of its first results.Lessons from Dark-Matter HalosWhy simulate the dark-matter halos of galaxies? Observationally, the formation history of our galaxy is encoded in galactic fossil record clues, like the tidal debris from disrupted satellite galaxies in the outer reaches of our galaxy, or chemical abundance patterns throughout our galactic disk and stellar halo.But to interpret this information in a way that lets us learn about our galaxys history, we need to first test galaxy formation and evolution scenarios via cosmological simulations. Then we can compare the end result of these simulations to what we observe today.This figure illustrates the difference that mass resolution makes. In the left panel, the mass resolution is 1.5*10^7 solar masses per particle. In the right panel, the mass resolution is 3*10^4 solar masses per particle [Griffen et al. 2016]A Computational ChallengeDue to how computationally expensive such simulations are, previous N-body simulations of the growth of Milky-Way-like halos have consisted of only one or a few halos each. But in order to establish a statistical understanding of how galaxy halos form and find out whether the Milky Ways halo is typical or unusual! it is necessary to simulate a larger number of halos.In addition, in order to accurately follow the formation and evolution of substructure within the dark-matter halos, these simulations must be able to resolve the smallest dwarf galaxies, which are around a million solar masses. This requires an extremely high mass resolution, which adds to the computational expense of the simulation.First OutcomesThese are the challenges faced by

  7. Final A&T stages of the Gemini Planet Finder

    Science.gov (United States)

    Hartung, Markus; Macintosh, Bruce; Poyneer, Lisa; Savransky, Dimitri; Gavel, Donald; Palmer, Dave; Thomas, Sandrine; Dillon, Daren; Chilcote, Jeffrey; Ingraham, Patrick; Sadakuni, Naru; Wallace, Kent; Perrin, Marshall; Marois, Christian; Maire, Jerome; Rantakyro, Fredrik; Hibon, Pascale; Saddlemyer, Les; Goodsell, Stephen

    2013-12-01

    The Gemini Planet Finder (GPI) is currently in its final Acceptance & Testing stages at the University of Santa Cruz, California. GPI is an XAO system based on a tweeter & woofer architecture (43 & 9 actuators across the pupil), with the tweeter being a Boston Michromachines 64^2 MEMS device. The XAO AO system is tightly integrated with a Lyot apodizing coronagraph. Acceptance has started in February 2013. After the conclusive acceptance review shipment is scheduled mid 2013 to ensure readiness for commissioning at the Gemini South telescope on Cerro Pachon, Chile, end of 2013, matching the summer window of the southern hemisphere. According to current estimates the 3 year (~800 allocated hours) planet finding campaign might discover, image, and spectroscopically analyze 20 to 40 new exo-planets.Final acceptance testing of the integrated instrument can always emerge a number of unforeseen challenges as we are eventually using cold chamber and flexure rig installations. The latest developments will be reported. Also, we will give an overview of GPI's lab performance, the interplay between subsystems such as the calibration unit (CAL) with the AO bench. (The CAL principal purpose is to maintain a clean and centered XAO PSF on the coronagraph.) We report on-going optimizations on the AO controler loop to filter vibrations and last but not least achieved contrast performance applying speckle nulling. Furthermore, we will give an outlook of possible but challenging future upgrades as the implementation of a predictive controler or exchanging the conventional 48x48 SH WFS with a pyramid. With the ELT area arising, GPI will proof as a versatile and path-finding testbed for AO technologies on the next generation of ground-based telescopes.

  8. Achieving autonomous data flow of the Automated Planet Finder (APF)

    Science.gov (United States)

    Burt, Jennifer; Hanson, Russell; Rivera, Eugenio; Holden, Brad; Vogt, Steven S.; Butler, R. Paul; Arriagada, Pamela; Laughlin, Greg

    2014-07-01

    The Automated Planet Finder (APF) is a dedicated, ground-based precision radial velocity facility located at Lick Observatory, operated by University of California Observatories (UCO), atop Mt. Hamilton in California. The 2.4-m telescope and accompanying high-resolution echelle spectrograph were specifically designed for the purpose of detecting planets in the liquid water habitable zone of low-mass stars. The telescope is operated every night (weather permitting) to achieve meaningful signal-to-noise gains from high cadence observing and to avoid the aliasing problems inherent to planets whose periods are close to the lunar month. To take full advantage of the consistent influx of data it is necessary to analyze each night's results before designing the next evening's target list. To address this requirement, we are in the process of developing a fully automated reduction pipeline that will take each night's data from raw FITS files to final radial velocity values and integrate those values into a master database. The database is then accessed by the publicly available Systemic console, a general-purpose software package for the analysis and combined multiparameter fitting of Doppler radial velocity observations. As each stellar system is updated, Systemic evaluates the probability that a planetary signal is present in the data, and uses this value, along with other considerations such as the star's brightness and chromospheric activity level, to assign it a priority rating for future observations. When the telescope is once again on sky it determines the optimal targets to observe in real time using an in-house dynamic scheduler.

  9. Revealing the Cosmic Web-dependent Halo Bias

    Science.gov (United States)

    Yang, Xiaohu; Zhang, Youcai; Lu, Tianhuan; Wang, Huiyuan; Shi, Feng; Tweed, Dylan; Li, Shijie; Luo, Wentao; Lu, Yi; Yang, Lei

    2017-10-01

    Halo bias is the one of the key ingredients of the halo models. It was shown at a given redshift to be only dependent, to the first order, on the halo mass. In this study, four types of cosmic web environments—clusters, filaments, sheets, and voids—are defined within a state-of-the-art high-resolution N-body simulation. Within these environments, we use both halo-dark matter cross correlation and halo-halo autocorrelation functions to probe the clustering properties of halos. The nature of the halo bias differs strongly between the four different cosmic web environments described here. With respect to the overall population, halos in clusters have significantly lower biases in the {10}11.0˜ {10}13.5 {h}-1 {M}⊙ mass range. In other environments, however, halos show extremely enhanced biases up to a factor 10 in voids for halos of mass ˜ {10}12.0 {h}-1 {M}⊙ . Such a strong cosmic web environment dependence in the halo bias may play an important role in future cosmological and galaxy formation studies. Within this cosmic web framework, the age dependency of halo bias is found to be only significant in clusters and filaments for relatively small halos ≲ {10}12.5 {h}-1 {M}⊙ .

  10. Electric Properties of One-Neutron Halo Nuclei in Halo EFT

    Science.gov (United States)

    Braun, Jonas; Hammer, Hans-Werner

    2017-03-01

    We exploit the separation of scales in weakly-bound nuclei to compute E2 transitions and electric form factors in a halo effective field theory (EFT) framework. The relevant degrees of freedom are the core and the halo neutron. The EFT expansion is carried out in powers of R_{core}/R_{halo}, where R_{core} and R_{halo} denote the length scales of the core and halo, respectively. We include the strong s-wave and d-wave interactions by introducing dimer fields. The dimer propagators are regulated by employing the power divergence subtraction scheme and matched to the effective range expansion in the respective channel. Electromagnetic interactions are included via minimal substitution in the Lagrangian. We demonstrate that, depending on the observable and respective partial wave, additional local gauge-invariant operators contribute in LO, NLO and higher orders.

  11. Quality scalable video data stream

    OpenAIRE

    Wiegand, T.; Kirchhoffer, H.; Schwarz, H

    2008-01-01

    An apparatus for generating a quality-scalable video data stream (36) is described which comprises means (42) for coding a video signal (18) using block-wise transformation to obtain transform blocks (146, 148) of transformation coefficient values for a picture (140) of the video signal, a predetermined scan order (154, 156, 164, 166) with possible scan positions being defined among the transformation coefficient values within the transform blocks so that in each transform block, for each pos...

  12. Dependence of halo bias on mass and environment

    Science.gov (United States)

    Shi, Jingjing; Sheth, Ravi K.

    2018-01-01

    The simplest analyses of halo bias assume that halo mass alone determines halo clustering. However, if the large-scale environment is fixed, then halo clustering is almost entirely determined by environment, and is almost completely independent of halo mass. We show why. Our analysis is useful for studies that use the environmental dependence of clustering to constrain cosmological and galaxy formation models. It also shows why many correlations between galaxy properties and environment are merely consequences of the underlying correlations between haloes and their environments, and provides a framework for quantifying such inherited correlations.

  13. Architecture trade study for the Terrestrial Planet Finder Interferometer

    Science.gov (United States)

    Lay, Oliver P.; Gunter, Steven M.; Hamlin, Louise A.; Henry, Curt A.; Li, Ying-Yong; Martin, Stefan R.; Purcell, George H., Jr.; Ware, Brent; Wertz, Julie A.; Noecker, M. Charley

    2005-08-01

    The Terrestrial Planet Finder Interferometer (TPF-I) is a space-based NASA mission for the direct detection of Earth-like planets orbiting nearby stars. At the mid-infrared wavelength range of interest, a sun-like star is ~107 times brighter than an earth-like planet, with an angular offset of ~50 mas. A set of formation-flying collector telescopes direct the incoming light to a common location where the beams are combined and detected. The relative locations of the collecting apertures, the way that the beams are routed to the combiner, and the relative amplitudes and phases with which they are combined constitute the architecture of the system. This paper evaluates six of the most promising solutions: the Linear Dual Chopped Bracewell (DCB), X-Array, Diamond DCB, Z-Array, Linear-3 and Triangle architectures. Each architecture is constrained to fit inside the shroud of a Delta IV Heavy launch vehicle using a parametric model for mass and volume. Both single and dual launch options are considered. The maximum separation between spacecraft is limited by stray light considerations. Given these constraints, the performance of each architecture is assessed by modeling the number of stars that can be surveyed and characterized spectroscopically during the mission lifetime, and by modeling the imaging properties of the configuration and the robustness to failures. The cost and risk for each architecture depends on a number of factors, including the number of launches, and mass margin. Quantitative metrics are used where possible. A matrix of the architectures and ~30 weighted discriminators was formed. Each architecture was assigned a score for each discriminator. Then the scores were multiplied by the weights and summed to give a total score for each architecture. The X-Array and Linear DCB were judged to be the strongest candidates. The simplicity of the three-collector architectures was not rated to be sufficient to compensate for their reduced performance and

  14. Stability of BEC galactic dark matter halos

    Energy Technology Data Exchange (ETDEWEB)

    Guzmán, F.S.; Lora-Clavijo, F.D.; González-Avilés, J.J.; Rivera-Paleo, F.J., E-mail: guzman@ifm.umich.mx, E-mail: fadulora@ifm.umich.mx, E-mail: javiles@ifm.umich.mx, E-mail: friverap@ifm.umich.mx [Instituto de Física y Matemáticas, Universidad Michoacana de San Nicolás de Hidalgo, Edificio C-3, Cd. Universitaria, 58040 Morelia, Michoacán (Mexico)

    2013-09-01

    In this paper we show that spherically symmetric BEC dark matter halos, with the sin r/r density profile, that accurately fit galactic rotation curves and represent a potential solution to the cusp-core problem are unstable. We do this by introducing back the density profiles into the fully time-dependent Gross-Pitaevskii-Poisson system of equations. Using numerical methods to track the evolution of the system, we found that these galactic halos lose mass at an approximate rate of half of its mass in a time scale of dozens of Myr. We consider this time scale is enough as to consider these halos are unstable and unlikely to be formed. We provide some arguments to show that this behavior is general and discuss some other drawbacks of the model that restrict its viability.

  15. LISA and LISA PathFinder, the endeavour to detect low frequency GWs

    Energy Technology Data Exchange (ETDEWEB)

    Araujo, H [Blackett Laboratory, Imperial College London, Prince Consort Road, London SW7 2BW (United Kingdom); Boatella, C [Institut d' Estudis Espacials de Catalunya (IEEC), Edifici Nexus, Gran Capita 2-4, 08034 Barcelona (Spain); Chmeissani, M [Institut de Fisica d' Altes Energies (IFAE), Edifici C, Universitat Autonoma de Barcelona, 08193 Bellaterra (Barcelona) (Spain); Conchillo, A [Institut d' Estudis Espacials de Catalunya (IEEC), Edifici Nexus, Gran Capita 2-4, 08034 Barcelona (Spain); Garcia-Berro, E [Institut d' Estudis Espacials de Catalunya (IEEC), Edifici Nexus, Gran Capita 2-4, 08034 Barcelona (Spain); Grimani, C [Universita degli Studi di Urbino, and INFN Florence, Istituto di Fisica, Via Santa Chiara 27, 61029 Urbino (Italy); Hajdas, W [Department of Particles and Matter, Paul Scherrer Institut, ODRA 120, 5232 Villigen (Switzerland); Lobo, A [Institut d' Estudis Espacials de Catalunya (IEEC), Edifici Nexus, Gran Capita 2-4, 08034 Barcelona (Spain); Martinez, L [AtIpic, Parc Tecnologic del Valles, 08290 Cerdanyola del Valles, Barcelona (Spain); Nofrarias, M [Institut d' Estudis Espacials de Catalunya (IEEC), Edifici Nexus, Gran Capita 2-4, 08034 Barcelona (Spain); Ortega, J A [Institut d' Estudis Espacials de Catalunya (IEEC), Edifici Nexus, Gran Capita 2-4, 08034 Barcelona (Spain); Puigdengoles, C [Institut de Fisica d' Altes Energies (IFAE), Edifici C, Universitat Autonoma de Barcelona, 08193 Bellaterra (Barcelona) (Spain); Ramos-Castro, J [Departament d' Enginyeria Electronica, UPC, Campus Nord, Edif. C4, Jordi Girona 1-3, 08034 Barcelona (Spain); Sanjuan, J [Institut d' Estudis Espacials de Catalunya (IEEC), Edifici Nexus, Gran Capita 2-4, 08034 Barcelona (Spain); Wass, P [Blackett Laboratory, Imperial College London, Prince Consort Road, London SW7 2BW (United Kingdom); Xirgu, X [Institut d' Estudis Espacials de Catalunya (IEEC), Edifici Nexus, Gran Capita 2-4, 08034 Barcelona (Spain)

    2007-05-15

    This is a review about LISA and its technology demonstrator, LISAPathFinder. We first describe the conceptual problems which need to be overcome in order to set up a working interferometric detector of low frequency Gravitational Waves (GW), then summarise the solutions to them as currently conceived by the LISA mission team. This will show that some of these solutions require new technological abilities which are still under development, and which need proper test before being fully implemented. LISAPathFinder (LPF) is the the testbed for such technologies. The final part of the paper will address the ideas and concepts behind the PathFinder as well as their impact on LISA.

  16. CT-Finder: A Web Service for CRISPR Optimal Target Prediction and Visualization.

    Science.gov (United States)

    Zhu, Houxiang; Misel, Lauren; Graham, Mitchell; Robinson, Michael L; Liang, Chun

    2016-05-23

    The CRISPR system holds much promise for successful genome engineering, but therapeutic, industrial, and research applications will place high demand on improving the specificity and efficiency of this tool. CT-Finder (http://bioinfolab.miamioh.edu/ct-finder) is a web service to help users design guide RNAs (gRNAs) optimized for specificity. CT-Finder accommodates the original single-gRNA Cas9 system and two specificity-enhancing paired-gRNA systems: Cas9 D10A nickases (Cas9n) and dimeric RNA-guided FokI nucleases (RFNs). Optimal target candidates can be chosen based on the minimization of predicted off-target effects. Graphical visualization of on-target and off-target sites in the genome is provided for target validation. Major model organisms are covered by this web service.

  17. The dark halo of the Milky Way.

    Science.gov (United States)

    Alcock, C.

    2000-01-01

    Most of the matter in the Milky Way is invisible to astronomers. Precise numbers are elusive, but it appears that the dark component is 20 times as massive as the visible disk of stars and gas. This dark matter is distributed in space differently than the stars, forming a vast, diffuse halo, more spherical than disklike, which occupies more than 1000 times the volume of the disk of stars. The composition of this dark halo is unknown, but it may comprise a mixture of ancient, degenerate dwarf stars and exotic, hypothetical elementary particles.

  18. Complex artificial halos for the classroom

    Science.gov (United States)

    Selmke, Markus; Selmke, Sarah

    2016-07-01

    Halos represent a common and imposing atmospheric optics phenomenon whose displays are caused by tiny air-borne ice crystals. Their variety stems from a certain set of orientation classes to which these crystals belong. We present a robust and inexpensive device, made of modular components, that allows for the replication of most of these orientation classes in the laboratory. Under the illumination of light, the corresponding artificial halo counterparts emerge. The mechanical realization of this device allows a thorough understanding and demonstration of these beautiful atmospheric optics phenomena.

  19. Dark energy and extended dark matter halos

    Science.gov (United States)

    Chernin, A. D.; Teerikorpi, P.; Valtonen, M. J.; Dolgachev, V. P.; Domozhilova, L. M.; Byrd, G. G.

    2012-03-01

    The cosmological mean matter (dark and baryonic) density measured in the units of the critical density is Ωm = 0.27. Independently, the local mean density is estimated to be Ωloc = 0.08-0.23 from recent data on galaxy groups at redshifts up to z = 0.01-0.03 (as published by Crook et al. 2007, ApJ, 655, 790 and Makarov & Karachentsev 2011, MNRAS, 412, 2498). If the lower values of Ωloc are reliable, as Makarov & Karachentsev and some other observers prefer, does this mean that the Local Universe of 100-300 Mpc across is an underdensity in the cosmic matter distribution? Or could it nevertheless be representative of the mean cosmic density or even be an overdensity due to the Local Supercluster therein. We focus on dark matter halos of groups of galaxies and check how much dark mass the invisible outer layers of the halos are able to host. The outer layers are usually devoid of bright galaxies and cannot be seen at large distances. The key factor which bounds the size of an isolated halo is the local antigravity produced by the omnipresent background of dark energy. A gravitationally bound halo does not extend beyond the zero-gravity surface where the gravity of matter and the antigravity of dark energy balance, thus defining a natural upper size of a system. We use our theory of local dynamical effects of dark energy to estimate the maximal sizes and masses of the extended dark halos. Using data from three recent catalogs of galaxy groups, we show that the calculated mass bounds conform with the assumption that a significant amount of dark matter is located in the invisible outer parts of the extended halos, sufficient to fill the gap between the observed and expected local matter density. Nearby groups of galaxies and the Virgo cluster have dark halos which seem to extend up to their zero-gravity surfaces. If the extended halo is a common feature of gravitationally bound systems on scales of galaxy groups and clusters, the Local Universe could be typical or even

  20. Development and implementation of a 'Mental Health Finder' software tool within an electronic medical record system.

    Science.gov (United States)

    Swan, D; Hannigan, A; Higgins, S; McDonnell, R; Meagher, D; Cullen, W

    2017-02-01

    In Ireland, as in many other healthcare systems, mental health service provision is being reconfigured with a move toward more care in the community, and particularly primary care. Recording and surveillance systems for mental health information and activities in primary care are needed for service planning and quality improvement. We describe the development and initial implementation of a software tool ('mental health finder') within a widely used primary care electronic medical record system (EMR) in Ireland to enable large-scale data collection on the epidemiology and management of mental health and substance use problems among patients attending general practice. In collaboration with the Irish Primary Care Research Network (IPCRN), we developed the 'Mental Health Finder' as a software plug-in to a commonly used primary care EMR system to facilitate data collection on mental health diagnoses and pharmacological treatments among patients. The finder searches for and identifies patients based on diagnostic coding and/or prescribed medicines. It was initially implemented among a convenience sample of six GP practices. Prevalence of mental health and substance use problems across the six practices, as identified by the finder, was 9.4% (range 6.9-12.7%). 61.9% of identified patients were female; 25.8% were private patients. One-third (33.4%) of identified patients were prescribed more than one class of psychotropic medication. Of the patients identified by the finder, 89.9% were identifiable via prescribing data, 23.7% via diagnostic coding. The finder is a feasible and promising methodology for large-scale data collection on mental health problems in primary care.

  1. One-proton halo in 26P and two-proton halo in 27S

    Science.gov (United States)

    Ren, Zhongzhou; Chen, Baoqiu; Ma, Zhongyu; Xu, Gongou

    1996-02-01

    Proton-drip-line nuclei 26P and 27S are studied in the nonlinear relativistic mean-field theory. Calculations show that the mean-square radius of protons in the 2s1/2 state is approximately 18-20 fm2 which is abnormally large as compared with the mean-square radii of proton, neutron, and matter distributions, giving a strong evidence for proton halos in 26P and 27S. This indicates that the size of proton halos is as large as that of neutron halos although there exists the Coulomb barrier in proton-drip-line nuclei.

  2. A 3D Voronoi+Gapper Galaxy Cluster Finder in Redshift Space to z ∼ 0.2 I: an Algorithm Optimized for the 2dFGRS

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Sebastián; Campusano, Luis E.; Hitschfeld-Kahler, Nancy; Pizarro, Daniel; Haines, Christopher P. [Universidad de Chile, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Santiago (Chile); Clowes, Roger G.; Marinello, Gabriel [Jeremiah Horrocks Institute, University of Central Lancashire, Preston PR1 2HE (United Kingdom); Söchting, Ilona K., E-mail: luis@das.uchile.cl [University of Oxford, Astrophysics, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH (United Kingdom)

    2017-04-01

    This paper is the first in a series, presenting a new galaxy cluster finder based on a three-dimensional Voronoi Tesselation plus a maximum likelihood estimator, followed by gapping-filtering in radial velocity(VoML+G). The scientific aim of the series is a reassessment of the diversity of optical clusters in the local universe. A mock galaxy database mimicking the southern strip of the magnitude(blue)-limited 2dF Galaxy Redshift Survey (2dFGRS), for the redshift range 0.009 < z < 0.22, is built on the basis of the Millennium Simulation of the LCDM cosmology and a reference catalog of “Millennium clusters,” spannning across the 1.0 × 10{sup 12}–1.0 × 10{sup 15} M {sub ⊙} h {sup −1} dark matter (DM) halo mass range, is recorded. The validation of VoML+G is performed through its application to the mock data and the ensuing determination of the completeness and purity of the cluster detections by comparison with the reference catalog. The execution of VoML+G over the 2dFGRS mock data identified 1614 clusters, 22% with N {sub g} ≥ 10, 64 percent with 10 > N {sub g} ≥ 5, and 14% with N {sub g} < 5. The ensemble of VoML+G clusters has a ∼59% completeness and a ∼66% purity, whereas the subsample with N {sub g} ≥ 10, to z ∼ 0.14, has greatly improved mean rates of ∼75% and ∼90%, respectively. The VoML+G cluster velocity dispersions are found to be compatible with those corresponding to “Millennium clusters” over the 300–1000 km s{sup −1} interval, i.e., for cluster halo masses in excess of ∼3.0 × 10{sup 13} M {sub ⊙} h {sup −1}.

  3. [Canal Finder System 89!!! Improvements and indications after 4 years of experimentation and use].

    Science.gov (United States)

    Lévy, G

    1990-01-01

    Actually, the CANAL FINDER SYSTEM is the only entirely automated endodontic device. After four years of existence, many evaluations were able to show the qualities of this system regarding root canal penetration, cleaning and shaping. The earlier concerns such as ergonomical problems were solved: automated extraction of the K-file, automated sodium hypochlorite irrigation. A new file was created, particularly well adapted to the root canal shaping of curved canals. This addition has improved the efficiency of the automated instrumentation. The CANAL FINDER SYSTEM has reached a maturity level permitting an excellent reliability and ease of use.

  4. Positive cloud-to-ground lightning detection by a direction-finder network

    Science.gov (United States)

    Macgorman, Donald R.; Taylor, William L.

    1989-01-01

    Consideration is given to the ability of an automatic direction-finder network to identify cloud-to-ground flashes that effectively lower positive charge to the ground (+CG flashes). Records from an extremely low frequency system are examined to determine whether or not 340 +CG flashes detected by the network have coincident waveforms characteristic of +CG flashes. It is found that false detection in the system is negligible for +CG flashes with range-normalized amplitudes of at least 50 direction-finder units. Also, it is shown that no more than about 15 percent of the +CG flashes detected by the system at smaller amplitudes are false detections.

  5. DUCHAMP: a 3D source finder for spectral-line data

    Science.gov (United States)

    Whiting, Matthew T.

    2012-04-01

    This paper describes the DUCHAMP source finder, a piece of software designed to find and describe sources in three-dimensional, spectral-line data cubes. DUCHAMP has been developed with H I (neutral hydrogen) observations in mind, but is widely applicable to many types of astronomical images. It features efficient source detection and handling methods, noise suppression via smoothing or multi-resolution wavelet reconstruction, and a range of graphical and text-based outputs to allow the user to understand the detections. This paper details some of the key algorithms used and illustrates the effectiveness of the finder on different data sets.

  6. EasyGene – a prokaryotic gene finder that ranks ORFs by statistical significance

    DEFF Research Database (Denmark)

    Larsen, Thomas Schou; Krogh, Anders Stærmose

    2003-01-01

    annotated as genes.Results: In this paper, we present a new automated gene-finding method, EasyGene, which estimates the statistical significance of a predicted gene. The gene finder is based on a hidden Markov model (HMM) that is automatically estimated for a new genome. Using extensions of similarities...... is the expected number of ORFs in one megabase of random sequence at the same significance level or better, where the random sequence has the same statistics as the genome in the sense of a third order Markov chain.Conclusions: The result is a flexible gene finder whose overall performance matches or exceeds...

  7. 3D Indoor Building Environment Reconstruction using calibration of Range finder Data

    DEFF Research Database (Denmark)

    Jamali, Ali; Anton, François; Rahman, Alias Abdul

    2015-01-01

    Measurement (EDM) and Terrestrial Laser Scanner (TLS) are mostly used. In this paper, several techniques for indoor 3D building data acquisition have been investigated. For reducing the time and cost of indoor building data acquisition process, the Trimble LaserAce 1000 range finder is used. The accuracy...... of the rangefinder is evaluated and a simple spatial model is reconstructed from real data. This technique is rapid (it requires a shorter time as compared to others), but the results show inconsistencies in horizontal angles for short distances in indoor environments. The range finder was calibrated using a least...

  8. Scalable Techniques for Formal Verification

    CERN Document Server

    Ray, Sandip

    2010-01-01

    This book presents state-of-the-art approaches to formal verification techniques to seamlessly integrate different formal verification methods within a single logical foundation. It should benefit researchers and practitioners looking to get a broad overview of the spectrum of formal verification techniques, as well as approaches to combining such techniques within a single framework. Coverage includes a range of case studies showing how such combination is fruitful in developing a scalable verification methodology for industrial designs. This book outlines both theoretical and practical issue

  9. Flexible scalable photonic manufacturing method

    Science.gov (United States)

    Skunes, Timothy A.; Case, Steven K.

    2003-06-01

    A process for flexible, scalable photonic manufacturing is described. Optical components are actively pre-aligned and secured to precision mounts. In a subsequent operation, the mounted optical components are passively placed onto a substrate known as an Optical Circuit Board (OCB). The passive placement may be either manual for low volume applications or with a pick-and-place robot for high volume applications. Mating registration features on the component mounts and the OCB facilitate accurate optical alignment. New photonic circuits may be created by changing the layout of the OCB. Predicted yield data from Monte Carlo tolerance simulations for two fiber optic photonic circuits is presented.

  10. Applications of the Integrated High-Performance CMOS Image Sensor to Range Finders - from Optical Triangulation to the Automotive Field.

    Science.gov (United States)

    Wu, Jih-Huah; Pen, Cheng-Chung; Jiang, Joe-Air

    2008-03-13

    With their significant features, the applications of complementary metal-oxidesemiconductor (CMOS) image sensors covers a very extensive range, from industrialautomation to traffic applications such as aiming systems, blind guidance, active/passiverange finders, etc. In this paper CMOS image sensor-based active and passive rangefinders are presented. The measurement scheme of the proposed active/passive rangefinders is based on a simple triangulation method. The designed range finders chieflyconsist of a CMOS image sensor and some light sources such as lasers or LEDs. Theimplementation cost of our range finders is quite low. Image processing software to adjustthe exposure time (ET) of the CMOS image sensor to enhance the performance oftriangulation-based range finders was also developed. An extensive series of experimentswere conducted to evaluate the performance of the designed range finders. From theexperimental results, the distance measurement resolutions achieved by the active rangefinder and the passive range finder can be better than 0.6% and 0.25% within themeasurement ranges of 1 to 8 m and 5 to 45 m, respectively. Feasibility tests onapplications of the developed CMOS image sensor-based range finders to the automotivefield were also conducted. The experimental results demonstrated that our range finders arewell-suited for distance measurements in this field.

  11. Hvilket lands lov finder anvendelse, når ophavsrettigheder krænkes på Internettet?

    DEFF Research Database (Denmark)

    Larsen, Torsten Bjørn

    2011-01-01

    Artiklen gennemgår de lovvalgsregler, der finder anvendelse i Danmark for ophavsretskrænkelser på Internettet......Artiklen gennemgår de lovvalgsregler, der finder anvendelse i Danmark for ophavsretskrænkelser på Internettet...

  12. GLS-Finder: An Automated Data-Mining System for Fast Profiling Glucosinolates and its Application in Brassica Vegetables

    Science.gov (United States)

    A rapid computer-aided program for profiling glucosinolates, “GLS-Finder", was developed. GLS-Finder is a Matlab script based expert system that is capable for qualitative and semi-quantitative analysis of glucosinolates in samples using data generated by ultra-high performance liquid chromatograph...

  13. SysFinder: A customized platform for search, comparison and assisted design of appropriate animal models based on systematic similarity.

    Science.gov (United States)

    Yang, Shuang; Zhang, Guoqing; Liu, Wan; Wang, Zhen; Zhang, Jifeng; Yang, Dongshan; Chen, Y Eugene; Sun, Hong; Li, Yixue

    2017-05-20

    Animal models are increasingly gaining values by cross-comparisons of response or resistance to clinical agents used for patients. However, many disease mechanisms and drug effects generated from animal models are not transferable to human. To address these issues, we developed SysFinder (http://lifecenter.sgst.cn/SysFinder), a platform for scientists to find appropriate animal models for translational research. SysFinder offers a "topic-centered" approach for systematic comparisons of human genes, whose functions are involved in a specific scientific topic, to the corresponding homologous genes of animal models. Scientific topic can be a certain disease, drug, gene function or biological pathway. SysFinder calculates multi-level similarity indexes to evaluate the similarities between human and animal models in specified scientific topics. Meanwhile, SysFinder offers species-specific information to investigate the differences in molecular mechanisms between humans and animal models. Furthermore, SysFinder provides a user-friendly platform for determination of short guide RNAs (sgRNAs) and homology arms to design a new animal model. Case studies illustrate the ability of SysFinder in helping experimental scientists. SysFinder is a useful platform for experimental scientists to carry out their research in the human molecular mechanisms. Copyright © 2017 Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, and Genetics Society of China. Published by Elsevier Ltd. All rights reserved.

  14. Substructure in the Stellar Halos of the Aquarius Simulations

    NARCIS (Netherlands)

    Helmi, Amina; Cooper, A. P.; White, S. D. M.; Cole, S.; Frenk, C. S.; Navarro, J. F.

    2011-01-01

    We characterize the substructure in the simulated stellar halos of Cooper et al. which were formed by the disruption of satellite galaxies within the cosmological N-body simulations of galactic halos of the Aquarius project. These stellar halos exhibit a wealth of tidal features: broad overdensities

  15. Highly Scalable Matching Pursuit Signal Decomposition Algorithm

    Data.gov (United States)

    National Aeronautics and Space Administration — In this research, we propose a variant of the classical Matching Pursuit Decomposition (MPD) algorithm with significantly improved scalability and computational...

  16. Perceptual compressive sensing scalability in mobile video

    Science.gov (United States)

    Bivolarski, Lazar

    2011-09-01

    Scalability features embedded within the video sequences allows for streaming over heterogeneous networks to a variety of end devices. Compressive sensing techniques that will allow for lowering the complexity increase the robustness of the video scalability are reviewed. Human visual system models are often used in establishing perceptual metrics that would evaluate quality of video. Combining of perceptual and compressive sensing approach outlined from recent investigations. The performance and the complexity of different scalability techniques are evaluated. Application of perceptual models to evaluation of the quality of compressive sensing scalability is considered in the near perceptually lossless case and to the appropriate coding schemes is reviewed.

  17. Scalable rendering on PC clusters

    Energy Technology Data Exchange (ETDEWEB)

    WYLIE,BRIAN N.; LEWIS,VASILY; SHIRLEY,DAVID NOYES; PAVLAKOS,CONSTANTINE

    2000-04-25

    This case study presents initial results from research targeted at the development of cost-effective scalable visualization and rendering technologies. The implementations of two 3D graphics libraries based on the popular sort-last and sort-middle parallel rendering techniques are discussed. An important goal of these implementations is to provide scalable rendering capability for extremely large datasets (>> 5 million polygons). Applications can use these libraries for either run-time visualization, by linking to an existing parallel simulation, or for traditional post-processing by linking to an interactive display program. The use of parallel, hardware-accelerated rendering on commodity hardware is leveraged to achieve high performance. Current performance results show that, using current hardware (a small 16-node cluster), they can utilize up to 85% of the aggregate graphics performance and achieve rendering rates in excess of 20 million polygons/second using OpenGL{reg_sign} with lighting, Gouraud shading, and individually specified triangles (not t-stripped).

  18. Halo white dwarfs in the Gaia era

    NARCIS (Netherlands)

    van Oirschot, P.; Nelemans, G.; Pols, O.; Helmi, A.; Tolstoy, E.; Brown, A. G. A.; Pugliese, G.; de Koter, A.; Wijburg, M.

    The Galactic Halo is the oldest and most metal-poor component of the Galaxy. It is studied in detail both to understand the formation and evolution of galaxies, as well as the formation and evolution of the earliest stars. With this aim in mind, we plan to couple a population synthesis model to a

  19. New (theoretical) Perspectives on the Galactic Halo

    NARCIS (Netherlands)

    Helmi, A.; Turon, C; Meynadier, F; Arenou, F

    1 discuss recent progress in our understanding of the formation of the stellar halo of the Milky Way in the context of the concordance cosmological model. The Gaia mission will provide unique insights especially into the early assembly of the Galaxy and likely be key in unraveling its merger

  20. Reflection halo twins : subsun and supersun

    NARCIS (Netherlands)

    Konnen, Gunther P.; van der Werf, Siebren Y.

    2011-01-01

    From an aircraft, a short distinct vertical structure is sometimes seen above the setting sun. Such a feature can be understood as a halo, which is the counterpart of the well-known subsun. Whereas the latter arises from reflections off basal faces of plate-oriented ice crystals illuminated from

  1. Streams in the Aquarius stellar haloes

    NARCIS (Netherlands)

    Gomez, Facundo A.; Helmi, Amina; Cooper, Andrew P.; Frenk, Carlos S.; Navarro, Julio F.; White, Simon D. M.

    2013-01-01

    We use the very high resolution, fully cosmological simulations from the Aquarius Project, coupled to a semi-analytical model of galaxy formation, to study the phase-space distribution of halo stars in 'solar neighbourhood' like volumes. We find that this distribution is very rich in substructure in

  2. The Impact of Theoretical Uncertainties in the Halo Mass Function and Halo

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Hao-Yi; Zentner, Andrew R.; Wechsler, Risa H.; /KIPAC, Menlo Park /SLAC /Pittsburgh U. /KIPAC, Menlo Park /SLAC

    2010-06-04

    We study the impact of theoretical uncertainty in the dark matter halo mass function and halo bias on dark energy constraints from imminent galaxy cluster surveys. We find that for an optical cluster survey like the Dark Energy Survey, the accuracy required on the predicted halo mass function to make it an insignificant source of error on dark energy parameters is {approx}1%. The analogous requirement on the predicted halo bias is less stringent ({approx}5%), particularly if the observable-mass distribution can be well constrained by other means. These requirements depend upon survey area but are relatively insensitive to survey depth. The most stringent requirements are likely to come from a survey over a significant fraction of the sky that aims to observe clusters down to relatively low mass, M{sub th}{approx} 10{sup 13.7} h{sup -1} M{sub sun}; for such a survey, the mass function and halo bias must be predicted to accuracies of {approx}0.5% and {approx}1%, respectively. These accuracies represent a limit on the practical need to calibrate ever more accurate halo mass and bias functions. We find that improving predictions for the mass function in the low-redshift and low-mass regimes is the most effective way to improve dark energy constraints.

  3. Parametrizing the stellar haloes of galaxies

    Science.gov (United States)

    D'Souza, Richard; Kauffman, Guinevere; Wang, Jing; Vegetti, Simona

    2014-09-01

    We study the stellar haloes of galaxies out to 70-100 kpc as a function of stellar mass and galaxy type by stacking aligned r- and g-band images from a sample of 45 508 galaxies from Sloan Digital Sky Survey Data Release 9 in the redshift range 0.06 ≤ z ≤ 0.1 and in the mass range 1010.0 M⊙ < M* < 1011.4 M⊙. We derive surface brightness profiles to a depth of almost μr ˜ 32 mag arcsec-2. We find that the ellipticity of the stellar halo is a function of galaxy stellar mass and that the haloes of high-concentration galaxies are more elliptical than those of low-concentration galaxies. Where the g - r colour of the stellar halo can be measured, we find that the stellar light is always bluer than in the main galaxy. The colour of the stellar halo is redder for more massive galaxies. We further demonstrate that the full two-dimensional surface intensity distribution of our galaxy stacks can only be fit through multicomponent Sérsic models. Using the fraction of light in the outer component of the models as a proxy for the fraction of accreted stellar light, we show that this fraction is a function of stellar mass and galaxy type. The fraction of accreted stellar light rises from 30 to 70 per cent and from 2 to 25 per cent for high- and low-concentration galaxies, respectively, over the mass range 1010.0-1011.4 M⊙.

  4. Modeling and Implementation of Multi-Position Non-Continuous Rotation Gyroscope North Finder.

    Science.gov (United States)

    Luo, Jun; Wang, Zhiqian; Shen, Chengwu; Kuijper, Arjan; Wen, Zhuoman; Liu, Shaojin

    2016-09-20

    Even when the Global Positioning System (GPS) signal is blocked, a rate gyroscope (gyro) north finder is capable of providing the required azimuth reference information to a certain extent. In order to measure the azimuth between the observer and the north direction very accurately, we propose a multi-position non-continuous rotation gyro north finding scheme. Our new generalized mathematical model analyzes the elements that affect the azimuth measurement precision and can thus provide high precision azimuth reference information. Based on the gyro's principle of detecting a projection of the earth rotation rate on its sensitive axis and the proposed north finding scheme, we are able to deduct an accurate mathematical model of the gyro outputs against azimuth with the gyro and shaft misalignments. Combining the gyro outputs model and the theory of propagation of uncertainty, some approaches to optimize north finding are provided, including reducing the gyro bias error, constraining the gyro random error, increasing the number of rotation points, improving rotation angle measurement precision, decreasing the gyro and the shaft misalignment angles. According them, a north finder setup is built and the azimuth uncertainty of 18" is obtained. This paper provides systematic theory for analyzing the details of the gyro north finder scheme from simulation to implementation. The proposed theory can guide both applied researchers in academia and advanced practitioners in industry for designing high precision robust north finder based on different types of rate gyroscopes.

  5. Problem-based learning using the online Medicare Part D Plan Finder tool.

    Science.gov (United States)

    Cutler, Timothy W; Stebbins, Marilyn R; Lai, Eric; Smith, Amanda R; Lipton, Helene Levens

    2008-06-15

    To implement didactic and problem-based learning curricular innovations aimed at increasing students' knowledge of Medicare Part D, improving their ability to apply the online Medicare Prescription Drug Plan Finder tool to a patient case, and improving their attitudes toward patient advocacy for Medicare beneficiaries. A survey instrument and a case-based online Medicare Prescription Drug Plan Finder tool exercise were administered to a single group (n = 120) of second-year pharmacy graduate students prior to and following completion of a course on health policy. Three domains (knowledge, skill mastery and attitudes) were measured before and after two 90-minute lectures on Medicare Part D. The online Medicare Prescription Drug Plan Finder exercise and Medicare Part D didactic lectures had positive effects on students' knowledge of Part D, attitudes toward patient advocacy, and ability to accurately use the Medicare Prescription Drug Plan Finder tool. The success of these didactic and problem-based curricular innovations in improving pharmacy students' knowledge, skills, and attitudes regarding Part D warrants further evaluation to determine their portability to clinical settings and other pharmacy schools.

  6. A Novel MEMS Gyro North Finder Design Based on the Rotation Modulation Technique.

    Science.gov (United States)

    Zhang, Yongjian; Zhou, Bin; Song, Mingliang; Hou, Bo; Xing, Haifeng; Zhang, Rong

    2017-04-28

    Gyro north finders have been widely used in maneuvering weapon orientation, oil drilling and other areas. This paper proposes a novel Micro-Electro-Mechanical System (MEMS) gyroscope north finder based on the rotation modulation (RM) technique. Two rotation modulation modes (static and dynamic modulation) are applied. Compared to the traditional gyro north finders, only one single MEMS gyroscope and one MEMS accelerometer are needed, reducing the total cost since high-precision gyroscopes and accelerometers are the most expensive components in gyro north finders. To reduce the volume and enhance the reliability, wireless power and wireless data transmission technique are introduced into the rotation modulation system for the first time. To enhance the system robustness, the robust least square method (RLSM) and robust Kalman filter (RKF) are applied in the static and dynamic north finding methods, respectively. Experimental characterization resulted in a static accuracy of 0.66° and a dynamic repeatability accuracy of 1°, respectively, confirming the excellent potential of the novel north finding system. The proposed single gyro and single accelerometer north finding scheme is universal, and can be an important reference to both scientific research and industrial applications.

  7. ChemINDEX Database; The Professional's Version of ChemFinder.Com

    OpenAIRE

    Roth, Dana L.

    2003-01-01

    ChemFinder.Com and ChemINDEX are interfaces that access the same database. ChemINDEX, however, provides greatly enhanced search, display and customization features (and without any pop-up ads). The common database has indexed nearly 80K compounds (with an additional 160K synonyms) from over 800 publicly available sites.

  8. Characteristic time for halo current growth and rotation

    Energy Technology Data Exchange (ETDEWEB)

    Boozer, Allen H., E-mail: ahb17@columbia.edu [Department of Applied Physics and Applied Mathematics, Columbia University, New York, New York 10027 (United States)

    2015-10-15

    A halo current flows for part of its path through the plasma edge and for part through the chamber walls and during tokamak disruptions can be as large as tenths of the plasma current. The primary interest in halo currents is the large force that they can exert on machine components particularly if the toriodal rotation of the halo current resonates with a natural oscillation frequency of the tokamak device. Halo currents arise when required to slow down the growth of a kink that is too unstable to be stabilized by the chamber walls. The width of the current channel in the halo plasma is comparable to the amplitude of the kink, and the halo current grows linearly, not exponentially, in time. The current density in the halo is comparable to that of the main plasma body. The rocket force due to plasma flowing out of the halo and recombining on the chamber walls can cause the non-axisymmetric magnetic structure produced by the kink to rotate toroidally at a speed comparable to the halo speed of sound. Gerhardt's observations of the halo current in NSTX shot 141 687 [Nucl. Fusion 53, 023005 (2013)] illustrate many features of the theory of halo currents and are discussed as a summary of the theory.

  9. Dynamics of the Disruption Halo Current Toroidal Asymmetry in NSTX

    Energy Technology Data Exchange (ETDEWEB)

    S.P. Gerhardt

    2012-09-27

    This paper describes the dynamics of disruption halo current non-axisymmetries in the lower divertor of the National Spherical Torus Experiment [M. Ono, et al. Nuclear Fusion 40, 557 (2000)]. While. The halo currents typically have a strongly asymmetric structure where they enter the divertor floor, and this asymmetry has been observed to complete up to 7 toroidal revolutions over the duration of the halo current pulse. However, the rotation speed and toroidal extend of the asymmetry can vary significantly during the pulse. The rotation speed, halo current pulse duration, and total number of revolutions tend to be smaller in cases with large halo currents. The halo current pattern is observed to become toroidally symmetric at the end of the halo current pulse. It is proposed that this symmeterization is due to the loss of most or all of the closed field line geometry in the final phase of the vertical displacement event.

  10. ORIGAMI: DELINEATING HALOS USING PHASE-SPACE FOLDS

    Energy Technology Data Exchange (ETDEWEB)

    Falck, Bridget L.; Neyrinck, Mark C.; Szalay, Alexander S. [Department of Physics and Astronomy, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218 (United States)

    2012-08-01

    We present the ORIGAMI method of identifying structures, particularly halos, in cosmological N-body simulations. Structure formation can be thought of as the folding of an initially flat three-dimensional manifold in six-dimensional phase space. ORIGAMI finds the outer folds that delineate these structures. Halo particles are identified as those that have undergone shell-crossing along three orthogonal axes, providing a dynamical definition of halo regions that is independent of density. ORIGAMI also identifies other morphological structures: particles that have undergone shell-crossing along 2, 1, or 0 orthogonal axes correspond to filaments, walls, and voids, respectively. We compare this method to a standard friends-of-friends halo-finding algorithm and find that ORIGAMI halos are somewhat larger, more diffuse, and less spherical, though the global properties of ORIGAMI halos are in good agreement with other modern halo-finding algorithms.

  11. Using Tidal Tails to Probe Dark Matter Halos

    Science.gov (United States)

    Mihos, Chris; Dubinski, John; Hernquist, Lars

    1995-03-01

    We present a series of numerical simulations of merging galaxies to explore the effect of differing halo mass distributions on the morphology of tidal tails. We employ composite disk/bulge/halo galaxy models which span a range of halo properties from low mass, compact halos to very massive, extended halos, and possess identically flat rotation curves inside a few disk scale lengths. These merger experiments are performed with a range of impact parameters, inclinations and mass ratios for the galaxies as well. Our simulations indicate that even under the most favorable conditions, galaxies with extended dark matter halos produce very anemic tidal tails when merging. In light of several observed mergers which sport prominent tidal tails --- e.g., NGC 7252, NGC 4038/39 (``The Antennae"), NGC 4676, and most spectacularly IRAS 19254-7245 (``The Superantennae") --- our results suggest that galaxy halos may be significantly more compact and less massive than expected in Omega =1 cosmological scenarios.

  12. Scalable Performance Measurement and Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Gamblin, Todd [Univ. of North Carolina, Chapel Hill, NC (United States)

    2009-01-01

    Concurrency levels in large-scale, distributed-memory supercomputers are rising exponentially. Modern machines may contain 100,000 or more microprocessor cores, and the largest of these, IBM's Blue Gene/L, contains over 200,000 cores. Future systems are expected to support millions of concurrent tasks. In this dissertation, we focus on efficient techniques for measuring and analyzing the performance of applications running on very large parallel machines. Tuning the performance of large-scale applications can be a subtle and time-consuming task because application developers must measure and interpret data from many independent processes. While the volume of the raw data scales linearly with the number of tasks in the running system, the number of tasks is growing exponentially, and data for even small systems quickly becomes unmanageable. Transporting performance data from so many processes over a network can perturb application performance and make measurements inaccurate, and storing such data would require a prohibitive amount of space. Moreover, even if it were stored, analyzing the data would be extremely time-consuming. In this dissertation, we present novel methods for reducing performance data volume. The first draws on multi-scale wavelet techniques from signal processing to compress systemwide, time-varying load-balance data. The second uses statistical sampling to select a small subset of running processes to generate low-volume traces. A third approach combines sampling and wavelet compression to stratify performance data adaptively at run-time and to reduce further the cost of sampled tracing. We have integrated these approaches into Libra, a toolset for scalable load-balance analysis. We present Libra and show how it can be used to analyze data from large scientific applications scalably.

  13. Scalable Parallel Density-based Clustering and Applications

    Science.gov (United States)

    Patwary, Mostofa Ali

    2014-04-01

    Recently, density-based clustering algorithms (DBSCAN and OPTICS) have gotten significant attention of the scientific community due to their unique capability of discovering arbitrary shaped clusters and eliminating noise data. These algorithms have several applications, which require high performance computing, including finding halos and subhalos (clusters) from massive cosmology data in astrophysics, analyzing satellite images, X-ray crystallography, and anomaly detection. However, parallelization of these algorithms are extremely challenging as they exhibit inherent sequential data access order, unbalanced workload resulting in low parallel efficiency. To break the data access sequentiality and to achieve high parallelism, we develop new parallel algorithms, both for DBSCAN and OPTICS, designed using graph algorithmic techniques. For example, our parallel DBSCAN algorithm exploits the similarities between DBSCAN and computing connected components. Using datasets containing up to a billion floating point numbers, we show that our parallel density-based clustering algorithms significantly outperform the existing algorithms, achieving speedups up to 27.5 on 40 cores on shared memory architecture and speedups up to 5,765 using 8,192 cores on distributed memory architecture. In our experiments, we found that while achieving the scalability, our algorithms produce clustering results with comparable quality to the classical algorithms.

  14. Precise halo orbit design and optimal transfer to halo orbits from earth using differential evolution

    Science.gov (United States)

    Nath, Pranav; Ramanan, R. V.

    2016-01-01

    The mission design to a halo orbit around the libration points from Earth involves two important steps. In the first step, we design a halo orbit for a specified size and in the second step, we obtain an optimal transfer trajectory design to the halo orbit from an Earth parking orbit. Conventionally, the preliminary design for these steps is obtained using higher order analytical solution and the dynamical systems theory respectively. Refinements of the design are carried out using gradient based methods such as differential correction and pseudo arc length continuation method under the of circular restricted three body model. In this paper, alternative single level schemes are developed for both of these steps based on differential evolution, an evolutionary optimization technique. The differential evolution based scheme for halo orbit design produces precise halo orbit design avoiding the refinement steps. Further, in this approach, prior knowledge of higher order analytical solutions for the halo orbit design is not needed. The differential evolution based scheme for the transfer trajectory, identifies the precise location on the halo orbit that needs minimum energy for insertion and avoids exploration of multiple points. The need of a close guess is removed because the present scheme operates on a set of bounds for the unknowns. The constraint on the closest approach altitude from Earth is handled through objective function. The use of these schemes as the design and analysis tools within the of circular restricted three body model is demonstrated through case studies for missions to the first libration point of Sun-Earth system.

  15. Simulation of disc-bulge-halo galaxies using parallel GPU based codes

    Science.gov (United States)

    Veles, O.; Berczik, P.; Just, A.

    2016-02-01

    We compare the performance of the very popular Tree-GPU code BONSAI with the older Particle-(Multi)Mesh code SUPERBOX. Both code we run on a same hardware using the GPU acceleration for the force calculation. SUPERBOX is a particle-mesh code with high resolution sub-grid and a higher order NGP (nearest grid point) force-calculation scheme. In our research, we are aiming to demonstrate that the new parallel version of SUPERBOX is capable to do the high resolution simulations of the interaction of the system of disc-bulge-halo composed galaxy. We describe the improvement of performance and scalability of SUPERBOX particularly for the Kepler cluster (NVIDIA K20 GPU). A comparison was made with the very popular and publicly available Tree-GPU code BONSAI†.

  16. Applications of the Integrated High-Performance CMOS Image Sensor to Range Finders — from Optical Triangulation to the Automotive Field

    Science.gov (United States)

    Wu, Jih-Huah; Pen, Cheng-Chung; Jiang, Joe-Air

    2008-01-01

    With their significant features, the applications of complementary metal-oxide semiconductor (CMOS) image sensors covers a very extensive range, from industrial automation to traffic applications such as aiming systems, blind guidance, active/passive range finders, etc. In this paper CMOS image sensor-based active and passive range finders are presented. The measurement scheme of the proposed active/passive range finders is based on a simple triangulation method. The designed range finders chiefly consist of a CMOS image sensor and some light sources such as lasers or LEDs. The implementation cost of our range finders is quite low. Image processing software to adjust the exposure time (ET) of the CMOS image sensor to enhance the performance of triangulation-based range finders was also developed. An extensive series of experiments were conducted to evaluate the performance of the designed range finders. From the experimental results, the distance measurement resolutions achieved by the active range finder and the passive range finder can be better than 0.6% and 0.25% within the measurement ranges of 1 to 8 m and 5 to 45 m, respectively. Feasibility tests on applications of the developed CMOS image sensor-based range finders to the automotive field were also conducted. The experimental results demonstrated that our range finders are well-suited for distance measurements in this field. PMID:27879789

  17. The Halo B2B Studio

    Science.gov (United States)

    Gorzynski, Mark; Derocher, Mike; Mitchell, April Slayden

    Research underway at Hewlett-Packard on remote communication resulted in the identification of three important components typically missing in existing systems. These missing components are: group nonverbal communication capabilities, high-resolution interactive data capabilities, and global services. Here we discuss some of the design elements in these three areas as part of the Halo program at HP, a remote communication system shown to be effective to end-users.

  18. Beam Shape and Halo Monitor Study

    CERN Document Server

    Lallement, J B; Hori, M; CERN. Geneva. AB Department

    2006-01-01

    The Beam Shape and Halo Monitor, designed by Masaki Hori, is the main diagnostic tool for the 3 MeV test stand scheduled in 2008. This detector will be able to measure the transverse halo generated in the RFQ and the Chopper-line and to detect and measure the longitudinal halo composed of the incompletely chopped bunches. Its principle of functioning is the following: H- ions hit a carbon foil and generate secondary electrons with the same spatial distribution than the incoming beam and a current depending on an emission coefficient given by the carbon foil. These electrons are accelerated towards a phosphor screen by an electric field applied between accelerating grids. Once the electrons reach the phosphor screen, they generate light which is transmitted to a CCD camera via optic fibers [1]. It is expected to give a time resolution of 1-2ns and a spatial resolution of 1mm. The first test of the BSHM done with a Laser has shown a spatial resolution bigger than 1cm and the time resolution bigger than 2ns[2]. ...

  19. Dissecting Halo Components in IFU Data

    Directory of Open Access Journals (Sweden)

    Michael Merrifield

    2017-05-01

    Full Text Available While most astronomers are now familiar with tools to decompose images into multiple components such as disks, bulges, and halos, the equivalent techniques for spectral data cubes are still in their infancy. This is unfortunate, as integral field unit (IFU spectral surveys are now producing a mass of data in this format, which we are ill-prepared to analyze effectively. We have therefore been developing new tools to separate out components using this full spectral data. The results of such analyses will prove invaluable in determining not only whether such decompositions have an astrophysical significance, but, where they do, also in determining the relationship between the various elements of a galaxy. Application to a pilot study of IFU data from the cD galaxy NGC 3311 confirms that the technique can separate the stellar halo from the underlying galaxy in such systems, and indicates that, in this case, the halo is older and more metal poor than the galaxy, consistent with it forming from the cannibalism of smaller satellite galaxies. The success of the method bodes well for its application to studying the larger samples of cD galaxies that IFU surveys are currently producing.

  20. The Extended Baryonic Halo of NGC 3923

    Directory of Open Access Journals (Sweden)

    Bryan W. Miller

    2017-07-01

    Full Text Available Galaxy halos and their globular cluster systems build up over time by the accretion of small satellites. We can learn about this process in detail by observing systems with ongoing accretion events and comparing the data with simulations. Elliptical shell galaxies are systems that are thought to be due to ongoing or recent minor mergers. We present preliminary results of an investigation of the baryonic halo—light profile, globular clusters, and shells/streams—of the shell galaxy NGC 3923 from deep Dark Energy Camera (DECam g and i-band imaging. We present the 2D and radial distributions of the globular cluster candidates out to a projected radius of about 185 kpc, or ∼ 37 R e , making this one of the most extended cluster systems studied. The total number of clusters implies a halo mass of M h ∼ 3 × 10 13 M ⊙ . Previous studies had identified between 22 and 42 shells, making NGC 3923 the system with the largest number of shells. We identify 23 strong shells and 11 that are uncertain. Future work will measure the halo mass and mass profile from the radial distributions of the shell, N-body models, and line-of-sight velocity distribution (LOSVD measurements of the shells using the Multi Unit Spectroscopic Explorer (MUSE.

  1. Quality Scalability Aware Watermarking for Visual Content.

    Science.gov (United States)

    Bhowmik, Deepayan; Abhayaratne, Charith

    2016-11-01

    Scalable coding-based content adaptation poses serious challenges to traditional watermarking algorithms, which do not consider the scalable coding structure and hence cannot guarantee correct watermark extraction in media consumption chain. In this paper, we propose a novel concept of scalable blind watermarking that ensures more robust watermark extraction at various compression ratios while not effecting the visual quality of host media. The proposed algorithm generates scalable and robust watermarked image code-stream that allows the user to constrain embedding distortion for target content adaptations. The watermarked image code-stream consists of hierarchically nested joint distortion-robustness coding atoms. The code-stream is generated by proposing a new wavelet domain blind watermarking algorithm guided by a quantization based binary tree. The code-stream can be truncated at any distortion-robustness atom to generate the watermarked image with the desired distortion-robustness requirements. A blind extractor is capable of extracting watermark data from the watermarked images. The algorithm is further extended to incorporate a bit-plane discarding-based quantization model used in scalable coding-based content adaptation, e.g., JPEG2000. This improves the robustness against quality scalability of JPEG2000 compression. The simulation results verify the feasibility of the proposed concept, its applications, and its improved robustness against quality scalable content adaptation. Our proposed algorithm also outperforms existing methods showing 35% improvement. In terms of robustness to quality scalable video content adaptation using Motion JPEG2000 and wavelet-based scalable video coding, the proposed method shows major improvement for video watermarking.

  2. Grassmann Averages for Scalable Robust PCA

    DEFF Research Database (Denmark)

    Hauberg, Søren; Feragen, Aasa; Black, Michael J.

    2014-01-01

    As the collection of large datasets becomes increasingly automated, the occurrence of outliers will increase—“big data” implies “big outliers”. While principal component analysis (PCA) is often used to reduce the size of data, and scalable solutions exist, it is well-known that outliers can arbit......, making it scalable to “big noisy data.” We demonstrate TGA for background modeling, video restoration, and shadow removal. We show scalability by performing robust PCA on the entire Star Wars IV movie....

  3. Fast and scalable inequality joins

    KAUST Repository

    Khayyat, Zuhair

    2016-09-07

    Inequality joins, which is to join relations with inequality conditions, are used in various applications. Optimizing joins has been the subject of intensive research ranging from efficient join algorithms such as sort-merge join, to the use of efficient indices such as (Formula presented.)-tree, (Formula presented.)-tree and Bitmap. However, inequality joins have received little attention and queries containing such joins are notably very slow. In this paper, we introduce fast inequality join algorithms based on sorted arrays and space-efficient bit-arrays. We further introduce a simple method to estimate the selectivity of inequality joins which is then used to optimize multiple predicate queries and multi-way joins. Moreover, we study an incremental inequality join algorithm to handle scenarios where data keeps changing. We have implemented a centralized version of these algorithms on top of PostgreSQL, a distributed version on top of Spark SQL, and an existing data cleaning system, Nadeef. By comparing our algorithms against well-known optimization techniques for inequality joins, we show our solution is more scalable and several orders of magnitude faster. © 2016 Springer-Verlag Berlin Heidelberg

  4. Scalable encryption using alpha rooting

    Science.gov (United States)

    Wharton, Eric J.; Panetta, Karen A.; Agaian, Sos S.

    2008-04-01

    Full and partial encryption methods are important for subscription based content providers, such as internet and cable TV pay channels. Providers need to be able to protect their products while at the same time being able to provide demonstrations to attract new customers without giving away the full value of the content. If an algorithm were introduced which could provide any level of full or partial encryption in a fast and cost effective manner, the applications to real-time commercial implementation would be numerous. In this paper, we present a novel application of alpha rooting, using it to achieve fast and straightforward scalable encryption with a single algorithm. We further present use of the measure of enhancement, the Logarithmic AME, to select optimal parameters for the partial encryption. When parameters are selected using the measure, the output image achieves a balance between protecting the important data in the image while still containing a good overall representation of the image. We will show results for this encryption method on a number of images, using histograms to evaluate the effectiveness of the encryption.

  5. Recoiling supermassive black hole escape velocities from dark matter haloes

    Science.gov (United States)

    Choksi, Nick; Behroozi, Peter; Volonteri, Marta; Schneider, Raffaella; Ma, Chung-Pei; Silk, Joseph; Moster, Benjamin

    2017-12-01

    We simulate recoiling black hole trajectories from z = 20 to z = 0 in dark matter haloes, quantifying how parameter choices affect escape velocities. These choices include the strength of dynamical friction, the presence of stars and gas, the accelerating expansion of the Universe (Hubble acceleration), host halo accretion and motion, and seed black hole mass. Lambda cold dark matter halo accretion increases escape velocities by up to 0.6 dex and significantly shortens return time-scales compared to non-accreting cases. Other parameters change orbit damping rates but have subdominant effects on escape velocities; dynamical friction is weak at halo escape velocities, even for extreme parameter values. We present formulae for black hole escape velocities as a function of host halo mass and redshift. Finally, we discuss how these findings affect black hole mass assembly as well as minimum stellar and halo masses necessary to retain supermassive black holes.

  6. The “Building Blocks” of Stellar Halos

    Directory of Open Access Journals (Sweden)

    Kyle A. Oman

    2017-08-01

    Full Text Available The stellar halos of galaxies encode their accretion histories. In particular, the median metallicity of a halo is determined primarily by the mass of the most massive accreted object. We use hydrodynamical cosmological simulations from the apostle project to study the connection between the stellar mass, the metallicity distribution, and the stellar age distribution of a halo and the identity of its most massive progenitor. We find that the stellar populations in an accreted halo typically resemble the old stellar populations in a present-day dwarf galaxy with a stellar mass ∼0.2–0.5 dex greater than that of the stellar halo. This suggests that had they not been accreted, the primary progenitors of stellar halos would have evolved to resemble typical nearby dwarf irregulars.

  7. SynergyFinder: a web application for analyzing drug combination dose-response matrix data.

    Science.gov (United States)

    Ianevski, Aleksandr; He, Liye; Aittokallio, Tero; Tang, Jing

    2017-08-01

    Rational design of drug combinations has become a promising strategy to tackle the drug sensitivity and resistance problem in cancer treatment. To systematically evaluate the pre-clinical significance of pairwise drug combinations, functional screening assays that probe combination effects in a dose-response matrix assay are commonly used. To facilitate the analysis of such drug combination experiments, we implemented a web application that uses key functions of R-package SynergyFinder, and provides not only the flexibility of using multiple synergy scoring models, but also a user-friendly interface for visualizing the drug combination landscapes in an interactive manner. The SynergyFinder web application is freely accessible at https://synergyfinder.fimm.fi ; The R-package and its source-code are freely available at http://bioconductor.org/packages/release/bioc/html/synergyfinder.html . jing.tang@helsinki.fi.

  8. The scheme of automatic pseudo Doppler software defined radio direction finder

    Directory of Open Access Journals (Sweden)

    Pavlyuk V.V.

    2017-04-01

    Full Text Available The research describes the implementation approaches of a pseudo Doppler radio direction finding method based on software defined radio technology. A block diagram of an automatic pseudo Doppler software defined radio direction finder is proposed. A hardware functional diagram of specialized software architecture is offered. New schematic solution for antenna commutator and beating software synchronization is realized. For smoothing the bearing measurement of an aperiodic cyclic field based filtering procedure is proposed. By mathematical and experimental modeling a key features of a pseudo Doppler software defined radio direction finder are proved in comparison with the classical implementation: short signals bearing ability, statistical smoothing algorithms implementation convenience, simultaneous multiple frequency channels direction finding possibility, processing information simplification, flexibility and reconfigurability of radio direction finding systems. A prototype that implements the proposed approaches, circuitry design, software and algorithmic solutions is developed.

  9. UP Finder: A COBRA toolbox extension for identifying gene overexpression strategies for targeted overproduction

    Directory of Open Access Journals (Sweden)

    Xi Wang

    2017-12-01

    Full Text Available Overexpression of key genes is a basic strategy for overproducing target products via metabolic engineering. Traditionally, identifying those key genes/pathways largely relies on the knowledge of biochemistry and bioinformatics. In this study, a modeling tool named UP Finder was developed to facilitate the rapid identification of gene overexpression strategies. It was based on the COBRA toolbox under MATLAB environment. All the key gene/pathway targets are identified in one click after simply loading a Systems Biology Markup Language model and specifying a metabolite as the targeted product. The outputs are also quantitatively ranked to show the preference for determining overexpression strategies in pathway design. Analysis examples for overproducing lycopene precursor in Escherichia coli and fatty acyl-ACP in the cyanobacterium Synechocystis sp. PCC 6803 by the UP Finder showed high degree of agreement with the reported key genes in the literatures.

  10. UP Finder: A COBRA toolbox extension for identifying gene overexpression strategies for targeted overproduction.

    Science.gov (United States)

    Wang, Xi; Yu, Liang; Chen, Shulin

    2017-12-01

    Overexpression of key genes is a basic strategy for overproducing target products via metabolic engineering. Traditionally, identifying those key genes/pathways largely relies on the knowledge of biochemistry and bioinformatics. In this study, a modeling tool named UP Finder was developed to facilitate the rapid identification of gene overexpression strategies. It was based on the COBRA toolbox under MATLAB environment. All the key gene/pathway targets are identified in one click after simply loading a Systems Biology Markup Language model and specifying a metabolite as the targeted product. The outputs are also quantitatively ranked to show the preference for determining overexpression strategies in pathway design. Analysis examples for overproducing lycopene precursor in Escherichia coli and fatty acyl-ACP in the cyanobacterium Synechocystis sp. PCC 6803 by the UP Finder showed high degree of agreement with the reported key genes in the literatures.

  11. Experimental study on the 1550 nm all fiber heterodyne laser range finder.

    Science.gov (United States)

    Yang, Fu; He, Yan; Shang, Jianhua; Chen, Weibiao

    2009-12-01

    In this paper, a 1550 nm all fiber monostatic laser range finder system based on linear chirp modulation and heterodyne detection is presented. The fiber end face signal is used as a range starting indicator. The transmitted laser power is 5 mW with a laser pulse length of 131 micros and a linear chirp bandwidth of 40 MHz. The telescope with an aperture of 3 cm couples the return light into a single mode fiber. Better than 14 cm distance accuracy and 26 dB SNR can be achieved for a wood target at a distance of about 43 m by using the above system setup. Several experiments with different system parameters are conducted. The system performance is tested under variable laser pulse length, linear chirp bandwidth, local oscillator power, and background noise. Finally, an application of the linear chirp modulation heterodyne laser range finder in a spaceborne ranging system is proposed.

  12. Finite Element Modeling on Scalable Parallel Computers

    Science.gov (United States)

    Cwik, T.; Zuffada, C.; Jamnejad, V.; Katz, D.

    1995-01-01

    A coupled finite element-integral equation was developed to model fields scattered from inhomogenous, three-dimensional objects of arbitrary shape. This paper outlines how to implement the software on a scalable parallel processor.

  13. PTXT Finder - an application for finding appropriate EHR data elements for data analysis using cross referencing information sources.

    Science.gov (United States)

    Lin, Jau-Huei; Haug, Peter J

    2007-10-11

    PTXT Finder was developed to reduce the manual efforts necessary to map from clinical variables in a decision support system to data elements in an EHR. The descriptions in a data dictionary may be inadequate for pinpointing data elements that represent a clinical variable. Semantics implied in taxonomy and real usage of the element are two important supporting information sources. PTXT Finder provides description, hierarchy, and statistics displays so users can cross-reference among these views.

  14. LISA and LISA PathFinder, the endeavour to detect low frequency GWs

    OpenAIRE

    Ara?jo, H; Boatella, C; Chmeissani, M; Conchillo, A; Garc?a-Berro, E; Grimani, C; Hajdas, W; Lobo, A; Mart?nez, L; Nofrarias, M; Ortega, JA; Puigdengoles, C; Ramos-Castro, J; Sanju?n, J; Wass, P

    2007-01-01

    This is a review about LISA and its technology demonstrator, LISA PathFinder. We first describe the conceptual problems which need to be overcome in order to set up a working interferometric detector of low frequency Gravitational Waves (GW), then summarise the solutions to them as currently conceived by the LISA mission team. This will show that some of these solutions require new technological abilities which are still under development, and which need proper test before being fully impleme...

  15. UP Finder: A COBRA toolbox extension for identifying gene overexpression strategies for targeted overproduction

    OpenAIRE

    Wang, Xi; Yu, Liang; Chen, Shulin

    2017-01-01

    Overexpression of key genes is a basic strategy for overproducing target products via metabolic engineering. Traditionally, identifying those key genes/pathways largely relies on the knowledge of biochemistry and bioinformatics. In this study, a modeling tool named UP Finder was developed to facilitate the rapid identification of gene overexpression strategies. It was based on the COBRA toolbox under MATLAB environment. All the key gene/pathway targets are identified in one click after simply...

  16. Corfu: A Platform for Scalable Consistency

    OpenAIRE

    Wei, Michael

    2017-01-01

    Corfu is a platform for building systems which are extremely scalable, strongly consistent and robust. Unlike other systems which weaken guarantees to provide better performance, we have built Corfu with a resilient fabric tuned and engineered for scalability and strong consistency at its core: the Corfu shared log. On top of the Corfu log, we have built a layer of advanced data services which leverage the properties of the Corfu log. Today, Corfu is already replacing data platforms in commer...

  17. Visual analytics in scalable visualization environments

    OpenAIRE

    Yamaoka, So

    2011-01-01

    Visual analytics is an interdisciplinary field that facilitates the analysis of the large volume of data through interactive visual interface. This dissertation focuses on the development of visual analytics techniques in scalable visualization environments. These scalable visualization environments offer a high-resolution, integrated virtual space, as well as a wide-open physical space that affords collaborative user interaction. At the same time, the sheer scale of these environments poses ...

  18. Reversed Halo Sign: Presents in Different Pulmonary Diseases.

    Directory of Open Access Journals (Sweden)

    Xi Zhan

    Full Text Available To observe the incidence of reversed halo sign in different pulmonary diseases and the pathological correspondence of reversed halo sign.Retrospectively studied the high resolution computer tomography scans of all the patients who were admitted in our department with abnormal pulmonary imaging, from 1st of January 2011 to 31st of December 2013, and all the cases with reversed halo sign on the high resolution computer tomography were collected. Clinical data such as pathological findings and confirmed diagnosis of the patients with reversed halo sign on the high resolution computer tomography scan were collected and summarized.Of 1546 abnormal High resolution computer tomography scans 108 had a reverse halo sign present, including 108 cases were observed with reversed halo sign in the high resolution computer tomography, including 40 cases of pulmonary tuberculosis, 43 cases of cryptogenic organizing pneumonia, 16 cases of lung cancer, 7 cases of sarcoidosis, and 1 case of pulmonary cryptococcosis, 1 case of granulomatosis with polyangiitis. Reversed halo sign had a higher incidence in granulomatous diseases (16.28% compared with non-granulomatous diseases (9.97%.Reversed halo sign is relatively non specific; it can be observed in different lung diseases, and different phases of diseases; reversed halo sign is more commonly found in granulomatous diseases compared with non-granulomatous diseases, and is most commonly observed in pulmonary tuberculosis among the granulomatous diseases, and in cryptogenic organizing pneumonia among the non-granulomatous diseases.

  19. Brightest galaxies as halo centre tracers in SDSS DR7

    Science.gov (United States)

    Lange, Johannes U.; van den Bosch, Frank C.; Hearin, Andrew; Campbell, Duncan; Zentner, Andrew R.; Villarreal, Antonio; Mao, Yao-Yuan

    2018-01-01

    Determining the positions of halo centres in large-scale structure surveys is crucial for many cosmological studies. A common assumption is that halo centres correspond to the location of their brightest member galaxies. In this paper, we study the dynamics of brightest galaxies with respect to other halo members in the Sloan Digital Sky Survey DR7. Specifically, we look at the line-of-sight velocity and spatial offsets between brightest galaxies and their neighbours. We compare those to detailed mock catalogues, constructed from high-resolution, dark-matter-only N-body simulations, in which it is assumed that satellite galaxies trace dark matter subhaloes. This allows us to place constraints on the fraction fBNC of haloes in which the brightest galaxy is not the central. Compared to previous studies, we explicitly take into account the unrelaxed state of the host haloes, velocity offsets of halo cores and correlations between fBNC and the satellite occupation. We find that fBNC strongly decreases with the luminosity of the brightest galaxy and increases with the mass of the host halo. Overall, in the halo mass range 1013-1014.5 h- 1M⊙ we find fBNC ∼ 30 per cent, in good agreement with a previous study by Skibba et al. We discuss the implications of these findings for studies inferring the galaxy-halo connection from satellite kinematics, models of the conditional luminosity function and galaxy formation in general.

  20. Fiber optic gyroscope dynamic north-finder algorithm modeling and analysis based on Simulink

    Science.gov (United States)

    Zhang, Zhengyi; Liu, Chuntong

    2017-09-01

    In view of the problems such as the lower automation level and the insufficient precision of the traditional fiber optic gyroscope (FOG) static north-finder, this paper focuses on the in-depth analysis of the FOG dynamic north-finder principle and algorithm. The simulation model of the FOG dynamic north found algorithm with the least square method by points is established using Simulink toolbox, and then the platform rotation speed and sampling frequency, which affect FOG dynamic north found precision obviously, are simulated and calculated, and the optimization analysis is carried out as a key consideration. The simulation results show that, when the platform rotation speed is between 4.5 °/s and 8.5 °/s and the sampling frequency is at about 50 Hz in the case of using the parameters of this paper, the FOG dynamic north finding system can reach the higher precision. And the conclusions can provide the reference and validation for the engineering and practical of FOG dynamic north-finder.

  1. Qibla Finder and Sholat Times Based on Digital Compass, GPS and Microprocessor

    Science.gov (United States)

    Sanjaya, W. S. M.; Anggraeni, D.; Nurrahman, F. I.; Kresnadjaja, W. G.; Dewi, I. P.; Mira; Aliah, H.; Marlina, L.

    2018-01-01

    To performing Sholat, Muslims around the world are required to pay attention to the requirements of Sholat, such as; determining the direction of the Qibla (Kaaba) and the time of Sholat. In this research will be made a real time Qibla Finder and Sholat Times named Q-Bot Ver3 to help Muslims find a Qibla direction and Time of Sholat anywhere. This Qibla Finder and Sholat Times are developed with robotic technology based on Digital Compass, GPS and Microcontroller. To determine the Qibla direction and Sholat times, latitude and longitude data form GPS module processed used spherical triangle trigonometry method, while the compass module used to show the Qibla direction. Moreover, this system has a buzzer which can sound if the device facing to the Qibla. This system is reliable and accurate in determining the Qibla Finder and Sholat Times. Thus, the advantage of the system is can correct the Qibla of Masjid and can help blind people to facing Qibla around the world.

  2. A New Data Concentrator for the CMS Muon Barrel Track Finder

    CERN Document Server

    Triossi, Andrea

    2014-01-01

    The CMS muon trigger will undergo considerable enhancements in preparation for the LHC \\mbox{run-2}. In order to improve rate reduction and efficiency the full muon trigger chain will be completely redesigned: the plan is to move from a redundant scheme, where the three subdetectors (CSC, DT, RPC) have a separate track finder, to three geographical track finders (barrel, endcap and overlap) that combine trigger primitives of each sub-detector. In particular, the muon barrel track finder (MBTF) will host a new algorithm, that aggregating DT and RPC trigger data, will be able to improve the fake rejection and the muon momentum measurement.This report will focus on the adaptive layer of the MBTF called TwinMux. Its primary role will be to merge, arrange and fan-out the slow optical links from the chambers in faster links (10 Gbps). It will realize a full connectivity matrix between the on-detector electronics and the MBTF allowing for different processing schemes. The TwinMux will be implemented in $\\mu$TCA for...

  3. PPInterFinder--a mining tool for extracting causal relations on human proteins from literature.

    Science.gov (United States)

    Raja, Kalpana; Subramani, Suresh; Natarajan, Jeyakumar

    2013-01-01

    One of the most common and challenging problem in biomedical text mining is to mine protein-protein interactions (PPIs) from MEDLINE abstracts and full-text research articles because PPIs play a major role in understanding the various biological processes and the impact of proteins in diseases. We implemented, PPInterFinder--a web-based text mining tool to extract human PPIs from biomedical literature. PPInterFinder uses relation keyword co-occurrences with protein names to extract information on PPIs from MEDLINE abstracts and consists of three phases. First, it identifies the relation keyword using a parser with Tregex and a relation keyword dictionary. Next, it automatically identifies the candidate PPI pairs with a set of rules related to PPI recognition. Finally, it extracts the relations by matching the sentence with a set of 11 specific patterns based on the syntactic nature of PPI pair. We find that PPInterFinder is capable of predicting PPIs with the accuracy of 66.05% on AIMED corpus and outperforms most of the existing systems. DATABASE URL: http://www.biomining-bu.in/ppinterfinder/

  4. Comparing operational performance of the Virtual Seismologist and FinDer for earthquake early warning.

    Science.gov (United States)

    Massin, Frederick; Boese, Maren; Cauzzi, Carlo V.; Clinton, John F.

    2017-04-01

    An earthquake early warning (EEW) system can provide fast and accurate parameter estimations across wide ranges of source dimensions, event types and epicentral distances by integrating event or ground motion parameter estimations from different EEW algorithms, each of them optimized for specific tasks. We have integrated two such independent EEW algorithms, Virtual Seismologist (VS) and FinDer in the popular open-source seismic monitoring framework, SeisComP3 (SC3). VS(SC3) provides rapid magnitude estimates for network-based point-source origins using conventional triggering and association, while FinDer matches evolving patterns of ground motion to track on-going rupture extent, and hence can provide accurate ground motion predictions for finite fault ruptures. SC3 is operated by a large number of regional seismic network across the world, many of which have a long term interest to develop EEW capabilities. By combining real-time performance with playbacks from significant events, we report on the configuration and performance of VS and FinDer in various different tectonic and monitoring environments - Switzerland, Nicaragua and Southern California. We discuss how real-time EEW reports from these complimentary algorithms can be combined in practice to provide a single EEW from the SC3 system.

  5. Optimization high vortex finder of cyclone separator with computational fluids dynamics simulation

    Directory of Open Access Journals (Sweden)

    Ni Ketut Caturwati

    2017-01-01

    Full Text Available Cyclone separator is an equipment that separates particles contained in the fluid without using filters. The dust particles in the flue gases can be separated by utilizing centrifugal forces and different densities of particles, so that the exhaust gases to be cleaner before discharged into the environment. In this paper carried out a simulation by Computational of Fluids Dynamics to determine the number of particles that can be separated in several cyclone separator which has a ratio body diameter against vortex finder high varied as : 1:0.5 ; 1:0.75 ; 1:1 ; 1:1.25 and 1:1.5. Fluid inlet are air with antrachite impurity particles that are commonly found in the exhaust gases from tire manufacturers with inlet velocities varied as: 15 m/s and 30 m/s. The results of simulation show the fluids with 15 m/s of inlet velocity is generate particle separation value is higher than the fluids with 30 m/s inlet velocity for ratio of body diameter and height vortex finder a: 1:0.5 and 1:1.5. For both of inlet velocities the best ratio of body diameter and height vortex finder is 1:1.25, where it has the highest values of percentage trapped particles about 86% for 30 m/s input velocity and also for 15 m/s input velocity.

  6. GLS-Finder: A Platform for Fast Profiling of Glucosinolates in Brassica Vegetables.

    Science.gov (United States)

    Sun, Jianghao; Zhang, Mengliang; Chen, Pei

    2016-06-01

    Mass spectrometry combined with related tandem techniques has become the most popular method for plant secondary metabolite characterization. We introduce a new strategy based on in-database searching, mass fragmentation behavior study, formula predicting for fast profiling of glucosinolates, a class of important compounds in brassica vegetables. A MATLAB script-based expert system computer program, "GLS-Finder", was developed. It is capable of qualitative and semi-quantitative analyses of glucosinolates in samples using data generated by ultrahigh-performance liquid chromatography-high-resolution accurate mass with multi-stage mass fragmentation (UHPLC-HRAM/MS(n)). A suite of bioinformatic tools was integrated into the "GLS-Finder" to perform raw data deconvolution, peak alignment, glucosinolate putative assignments, semi-quantitation, and unsupervised principal component analysis (PCA). GLS-Finder was successfully applied to identify intact glucosinolates in 49 commonly consumed Brassica vegetable samples in the United States. It is believed that this work introduces a new way of fast data processing and interpretation for qualitative and quantitative analyses of glucosinolates, where great efficacy was improved in comparison to identification manually.

  7. Fully scalable video coding in multicast applications

    Science.gov (United States)

    Lerouge, Sam; De Sutter, Robbie; Lambert, Peter; Van de Walle, Rik

    2004-01-01

    The increasing diversity of the characteristics of the terminals and networks that are used to access multimedia content through the internet introduces new challenges for the distribution of multimedia data. Scalable video coding will be one of the elementary solutions in this domain. This type of coding allows to adapt an encoded video sequence to the limitations of the network or the receiving device by means of very basic operations. Algorithms for creating fully scalable video streams, in which multiple types of scalability are offered at the same time, are becoming mature. On the other hand, research on applications that use such bitstreams is only recently emerging. In this paper, we introduce a mathematical model for describing such bitstreams. In addition, we show how we can model applications that use scalable bitstreams by means of definitions that are built on top of this model. In particular, we chose to describe a multicast protocol that is targeted at scalable bitstreams. This way, we will demonstrate that it is possible to define an abstract model for scalable bitstreams, that can be used as a tool for reasoning about such bitstreams and related applications.

  8. Mapping stellar content to dark matter haloes - II. Halo mass is the main driver of galaxy quenching

    Science.gov (United States)

    Zu, Ying; Mandelbaum, Rachel

    2016-04-01

    We develop a simple yet comprehensive method to distinguish the underlying drivers of galaxy quenching, using the clustering and galaxy-galaxy lensing of red and blue galaxies in Sloan Digital Sky Survey. Building on the iHOD framework developed by Zu & Mandelbaum, we consider two quenching scenarios: (1) a `halo' quenching model in which halo mass is the sole driver for turning off star formation in both centrals and satellites; and (2) a `hybrid' quenching model in which the quenched fraction of galaxies depends on their stellar mass, while the satellite quenching has an extra dependence on halo mass. The two best-fitting models describe the red galaxy clustering and lensing equally well, but halo quenching provides significantly better fits to the blue galaxies above 1011 h-2 M⊙. The halo quenching model also correctly predicts the average halo mass of the red and blue centrals, showing excellent agreement with the direct weak lensing measurements of locally brightest galaxies. Models in which quenching is not tied to halo mass, including an age-matching model in which galaxy colour depends on halo age at fixed M*, fail to reproduce the observed halo mass for massive blue centrals. We find similar critical halo masses responsible for the quenching of centrals and satellites (˜1.5 × 1012 h-1 M⊙), hinting at a uniform quenching mechanism for both, e.g. the virial shock heating of infalling gas. The success of the iHOD halo quenching model provides strong evidence that the physical mechanism that quenches star formation in galaxies is tied principally to the masses of their dark matter haloes rather than the properties of their stellar components.

  9. Comparison of three multiplex PCR assays for the detection of respiratory viral infections: evaluation of xTAG respiratory virus panel fast assay, RespiFinder 19 assay and RespiFinder SMART 22 assay

    Directory of Open Access Journals (Sweden)

    Dabisch-Ruthe Mareike

    2012-07-01

    Full Text Available Abstract Background A broad spectrum of pathogens is causative for respiratory tract infections, but symptoms are mostly similar. Therefore, the identification of the causative viruses and bacteria is only feasible using multiplex PCR or several monoplex PCR tests in parallel. Methods The analytical sensitivity of three multiplex PCR assays, RespiFinder-19, RespiFinder-SMART-22 and xTAG-Respiratory-Virus-Panel-Fast-Assay (RVP, were compared to monoplex real-time PCR with quantified standardized control material. All assays include the most common respiratory pathogens. Results To compare the analytical sensitivity of the multiplex assays, samples were inoculated with 13 different quantified viruses in the range of 101 to 105 copies/ml. Concordant results were received for rhinovirus, whereas the RVP detected influenzavirus, RSV and hMPV more frequently in low concentrations. The RespiFinder-19 and the RespiFinder-SMART-22 showed a higher analytical sensitivity for adenoviruses and coronaviruses, whereas the RVP was incapable to detect adenovirus and coronavirus in concentrations of 104 copies/ml. The RespiFinder-19 and RespiFinder-SMART-22A did not detect influenzaviruses (104 copies/ml and RSV (103 copies/ml. The detection of all 13 viruses in one sample was only achieved using monoplex PCR. To analyze possible competitive amplification reactions between the different viruses, samples were further inoculated with only 4 different viruses in one sample. Compared to the detection of 13 viruses in parallel, only a few differences were found. The incidence of respiratory viruses was compared in tracheal secretion (TS samples (n = 100 of mechanically ventilated patients in winter (n = 50 and summer (n = 50. In winter, respiratory viruses were detected in 32 TS samples (64% by RespiFinder-19, whereas the detection rate with RVP was only 22%. The most frequent viruses were adenovirus (32% and PIV-2 (20%. Multiple infections were detected

  10. Clustering dark energy and halo abundances

    Science.gov (United States)

    Batista, Ronaldo C.; Marra, Valerio

    2017-11-01

    Within the standard paradigm, dark energy is taken as a homogeneous fluid that drives the accelerated expansion of the universe and does not contribute to the mass of collapsed objects such as galaxies and galaxy clusters. The abundance of galaxy clusters—measured through a variety of channels—has been extensively used to constrain the normalization of the power spectrum: it is an important probe as it allows us to test if the standard ΛCDM model can indeed accurately describe the evolution of structures across billions of years. It is then quite significant that the Planck satellite has detected, via the Sunyaev-Zel'dovich effect, less clusters than expected according to the primary CMB anisotropies. One of the simplest generalizations that could reconcile these observations is to consider models in which dark energy is allowed to cluster, i.e., allowing its sound speed to vary. In this case, however, the standard methods to compute the abundance of galaxy clusters need to be adapted to account for the contributions of dark energy. In particular, we examine the case of clustering dark energy—a dark energy fluid with negligible sound speed—with a redshift-dependent equation of state. We carefully study how the halo mass function is modified in this scenario, highlighting corrections that have not been considered before in the literature. We address modifications in the growth function, collapse threshold, virialization densities and also changes in the comoving scale of collapse and mass function normalization. Our results show that clustering dark energy can impact halo abundances at the level of 10%-30%, depending on the halo mass, and that cluster counts are modified by about 30% at a redshift of unity.

  11. Fast low-energy halo-to-halo transfers between Sun–planet systems

    Directory of Open Access Journals (Sweden)

    Shang Haibin

    2014-04-01

    Full Text Available In this paper, the problem of fast low-energy halo-to-halo transfers between Sun–planet systems is discussed under ephemeris constraints. According to the structure of an invariant manifold, employing an invariant manifold and planetary gravity assist to save fuel consumption is analyzed from the view of orbital energy. Then, a pseudo-manifold is introduced to replace the invariant manifold in such a way that more transfer opportunities are allowed. Fast escape and capture can be achieved along the pseudo-manifold. Furthermore, a global searching method that is based on patched-models is proposed to find an appropriate transfer trajectory. In this searching method, the trajectory is divided into several segments that can be designed under simple dynamical models, and an analytical algorithm is developed for connecting the segments. Earth–Mars and Earth–Venus halo-to-halo transfers are designed to demonstrate the proposed approach. Numerical results show that the transfers that combine the pseudo-manifolds and planetary gravity assist can offer significant fuel consumption and flight time savings over traditional transfer schemes.

  12. Haloes, molecules and multi-neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Marques Moreno, F.M

    2003-01-01

    Away from the equilibrium between protons and neutrons within stable nuclei, many exotic nuclei exist. Most of the known nuclear properties evolve smoothly with exoticism, but some extreme proton-neutron combinations have revealed during the last decade completely new concepts. They will be illustrated through three examples: the extended and dilute halo formed by very weakly bound neutrons, the molecular-like neutron orbitals found in nuclei exhibiting a clustering, and the recently revived debate on the possible existence of neutral nuclei. The different experimental results will be reviewed, and we will see how several properties of these new phenomena can be well understood within relatively simple theoretical approaches. (author)

  13. Clustering and correlations in neutrons haloes

    Energy Technology Data Exchange (ETDEWEB)

    Orr, N.A

    2002-02-01

    In the present paper clustering and correlations within halo systems is explored. In particular, the application of neutron-neutron interferometry and Dalitz-plot type analyses is presented through the example provided by the dissociation of {sup 14}Be. A novel approach for producing and detection bound neutron clusters is also described. The observation of some 6 events with characteristics consistent with the liberation of a multi-neutron cluster in the breakup of {sup 14}Be - possibly in the channel {sup 10}Be+{sup 4}n - is discussed. (author)

  14. Project ECHO: Electronic Communications from Halo Orbit

    Science.gov (United States)

    Borrelli, Jason; Cooley, Bryan; Debole, Marcy; Hrivnak, Lance; Nielsen, Kenneth; Sangmeister, Gary; Wolfe, Matthew

    1994-01-01

    The design of a communications relay to provide constant access between the Earth and the far side of the Moon is presented. Placement of the relay in a halo orbit about the L2 Earth-Moon Lagrange point allows the satellite to maintain constant simultaneous communication between Earth and scientific payloads on the far side of the Moon. The requirements of NASA's Discovery-class missions adopted and modified for this design are: total project cost should not exceed $150 million excluding launch costs, launch must be provided by Delta-class vehicle, and the satellite should maintain an operational lifetime of 10 to 15 years. The spacecraft will follow a transfer trajectory to the L2 point, after launch by a Delta II 7925 vehicle in 1999. Low-level thrust is used for injection into a stationkeeping-free halo orbit once the spacecraft reaches the L2 point. The shape of this halo orbit is highly elliptical with the maximum excursion from the L2 point being 35000 km. A spun section and despun section connected through a bearing and power transfer assembly (BAPTA) compose the structure of the spacecraft. Communications equipment is placed on the despun section to provide for a stationary dual parabolic offset-feed array antenna system. The dual system is necessary to provide communications coverage during portions of maximum excursion on the halo orbit. Transmissions to the NASA Deep Space Network 34 m antenna include six channels (color video, two voice, scientific data from lunar payloads, satellite housekeeping and telemetry and uplinked commands) using the S- and X-bands. Four radioisotope thermoelectric generators (RTG's) provide a total of 1360 W to power onboard systems and any two of the four Hughes 13 cm ion thrusters at once. Output of the ion thrusters is approximately 17.8 mN each with xenon as the propellant. Presence of torques generated by solar pressure on the antenna dish require the addition of a 'skirt' extending from the spun section of the satellite

  15. Universal properties of dark matter halos.

    Science.gov (United States)

    Boyarsky, A; Neronov, A; Ruchayskiy, O; Tkachev, I

    2010-05-14

    We discuss the universal relation between density and size of observed dark matter halos that was recently shown to hold on a wide range of scales, from dwarf galaxies to galaxy clusters. Predictions of cold dark matter (ΛCDM) N-body simulations are consistent with this relation. We demonstrate that this property of ΛCDM can be understood analytically in the secondary infall model. Qualitative understanding given by this model provides a new way to predict which deviations from ΛCDM or large-scale modifications of gravity can affect universal behavior and, therefore, to constrain them observationally.

  16. Stellar Mass—Halo Mass Relation and Star Formation Efficiency in High-Mass Halos

    Science.gov (United States)

    Kravtsov, A. V.; Vikhlinin, A. A.; Meshcheryakov, A. V.

    2018-01-01

    We study relation between stellar mass and halo mass for high-mass halos using a sample of galaxy clusters with accurate measurements of stellar masses from optical and ifrared data and total masses from X-ray observations. We find that stellar mass of the brightest cluster galaxies (BCGs) scales as M *,BCG ∝ M 500 αBCG with the best fit slope of α BCG ≈ 0.4 ± 0.1. We measure scatter of M *,BCG at a fixed M 500 of ≈0.2 dex. We show that stellar mass-halo mass relations from abundance matching or halo modelling reported in recent studies underestimate masses of BCGs by a factor of ˜2-4. We argue that this is because these studies used stellar mass functions (SMF) based on photometry that severely underestimates the outer surface brightness profiles of massive galaxies. We show that M * -M relation derived using abundance matching with the recent SMF calibration by Bernardi et al. (2013) based on improved photometry is in a much better agreement with the relation we derive via direct calibration for observed clusters. The total stellar mass of galaxies correlates with total mass M 500 with the slope of ≈0.6 ± 0.1 and scatter of 0.1 dex. This indicates that efficiency with which baryons are converted into stars decreases with increasing cluster mass. The low scatter is due to large contribution of satellite galaxies: the stellar mass in satellite galaxies correlates with M 500 with scatter of ≈0.1 dex and best fit slope of αsat ≈ 0.8 ± 0.1. We show that for a fixed choice of the initial mass function (IMF) total stellar fraction in clusters is only a factor of 3-5 lower than the peak stellar fraction reached in M ≈ 1012 M ⊙ halos. The difference is only a factor of ˜1.5-3 if the IMF becomes progressively more bottom heavy with increasing mass in early type galaxies, as indicated by recent observational analyses. This means that the overall efficiency of star formation in massive halos is only moderately suppressed compared to L * galaxies and

  17. The Prevalence of the 22 deg Halo in Cirrus Clouds

    Science.gov (United States)

    Diedenhoven, vanBastiaan

    2014-01-01

    Halos at 22 deg from the sun attributed to randomly-orientated, pristine hexagonal crystals are frequently observed through ice clouds. These frequent sightings of halos formed by pristine crystals pose an apparent inconsistency with the dominance of distorted, nonpristine ice crystals indicated by in situ and remote sensing data. Furthermore, the 46 deg halo, which is associated with pristine hexagonal crystals as well, is observed far less frequently than the 22 deg halo. Considering that plausible mechanisms that could cause crystal distortion such as aggregation, sublimation, riming and collisions are stochastic processes that likely lead to distributions of crystals with varying distortion levels, here the presence of the 22 deg and 46 deg halo features in phase functions of mixtures of pristine and distorted hexagonal ice crystals is examined. We conclude that the 22 deg halo feature is generally present if the contribution by pristine crystals to the total scattering cross section is greater than only about 10% in the case of compact particles or columns, and greater than about 40% for plates. The 46 deg halo feature is present only if the mean distortion level is low and the contribution of pristine crystals to the total scattering cross section is above about 20%, 50% and 70%, in the case of compact crystals, plates and columns, respectively. These results indicate that frequent sightings of 22 deg halos are not inconsistent with the observed dominance of distorted, non-pristine ice crystals. Furthermore, the low mean distortion levels and large contributions by pristine crystals needed to produce the 461 halo features provide a potential explanation of the common sighting of the 22 deg halo without any detectable 46 deg halo.

  18. Diverse stellar haloes in nearby Milky Way mass disc galaxies

    Science.gov (United States)

    Harmsen, Benjamin; Monachesi, Antonela; Bell, Eric F.; de Jong, Roelof S.; Bailin, Jeremy; Radburn-Smith, David J.; Holwerda, Benne W.

    2017-04-01

    We have examined the resolved stellar populations at large galactocentric distances along the minor axis (from 10 kpc up to between 40 and 75 kpc), with limited major axis coverage, of six nearby highly inclined Milky Way (MW) mass disc galaxies using Hubble Space Telescope data from the Galaxy haloes, Outer discs, Substructure, Thick discs, and Star clusters (GHOSTS) survey. We select red giant branch stars to derive stellar halo density profiles. The projected minor axis density profiles can be approximated by power laws with projected slopes of -2 to -3.7 and a diversity of stellar halo masses of 1-6 × 109 M⊙, or 2-14 per cent of the total galaxy stellar masses. The typical intrinsic scatter around a smooth power-law fit is 0.05-0.1 dex owing to substructure. By comparing the minor and major axis profiles, we infer projected axis ratios c/a at ˜25 kpc between 0.4and0.75. The GHOSTS stellar haloes are diverse, lying between the extremes charted out by the (rather atypical) haloes of the MW and M31. We find a strong correlation between the stellar halo metallicities and the stellar halo masses. We compare our results with cosmological models, finding good agreement between our observations and accretion-only models where the stellar haloes are formed by the disruption of dwarf satellites. In particular, the strong observed correlation between stellar halo metallicity and mass is naturally reproduced. Low-resolution hydrodynamical models have unrealistically high stellar halo masses. Current high-resolution hydrodynamical models appear to predict stellar halo masses somewhat higher than observed but with reasonable metallicities, metallicity gradients, and density profiles.

  19. 77 FR 75672 - Manufacturer of Controlled Substances, Notice of Registration, Halo Pharmaceutical, Inc.

    Science.gov (United States)

    2012-12-21

    ... Enforcement Administration Manufacturer of Controlled Substances, Notice of Registration, Halo Pharmaceutical... 47114, Halo Pharmaceutical, Inc., 30 North Jefferson Road, Whippany, New Jersey 07981, made application... determined that the registration of Halo Pharmaceutical, Inc., to manufacture the listed basic classes of...

  20. 77 FR 16264 - Manufacturer of Controlled Substances, Notice of Registration; Halo Pharmaceutical Inc.

    Science.gov (United States)

    2012-03-20

    ... Enforcement Administration Manufacturer of Controlled Substances, Notice of Registration; Halo Pharmaceutical... FR 77850, Halo Pharmaceutical Inc., 30 North Jefferson Road, Whippany, New Jersey 07981, made... determined that the registration of Halo Pharmaceutical Inc. to manufacture the listed basic classes of...

  1. Convergence properties of halo merger trees; halo and substructure merger rates across cosmic history

    Science.gov (United States)

    Poole, Gregory B.; Mutch, Simon J.; Croton, Darren J.; Wyithe, Stuart

    2017-12-01

    We introduce GBPTREES: an algorithm for constructing merger trees from cosmological simulations, designed to identify and correct for pathological cases introduced by errors or ambiguities in the halo finding process. GBPTREES is built upon a halo matching method utilizing pseudo-radial moments constructed from radially sorted particle ID lists (no other information is required) and a scheme for classifying merger tree pathologies from networks of matches made to-and-from haloes across snapshots ranging forward-and-backward in time. Focusing on SUBFIND catalogues for this work, a sweep of parameters influencing our merger tree construction yields the optimal snapshot cadence and scanning range required for converged results. Pathologies proliferate when snapshots are spaced by ≲0.128 dynamical times; conveniently similar to that needed for convergence of semi-analytical modelling, as established by Benson et al. Total merger counts are converged at the level of ∼5 per cent for friends-of-friends (FoF) haloes of size np ≳ 75 across a factor of 512 in mass resolution, but substructure rates converge more slowly with mass resolution, reaching convergence of ∼10 per cent for np ≳ 100 and particle mass mp ≲ 109 M⊙. We present analytic fits to FoF and substructure merger rates across nearly all observed galactic history (z ≤ 8.5). While we find good agreement with the results presented by Fakhouri et al. for FoF haloes, a slightly flatter dependence on merger ratio and increased major merger rates are found, reducing previously reported discrepancies with extended Press-Schechter estimates. When appropriately defined, substructure merger rates show a similar mass ratio dependence as FoF rates, but with stronger mass and redshift dependencies for their normalization.

  2. Alternative techniques for beam halo measurements

    CERN Document Server

    Welsch, CP; Burel, B; Lefèvre, T; Chapman, T; Pilon, MJ

    2006-01-01

    In future high intensity, high energy accelerators it must be ensured that particle losses are minimized, as activation of the vacuum chambers or other components makes maintenance and upgrade work time consuming and costly. It is imperative to have a clear understanding of the mechanisms that can lead to halo formation and to have the possibility to test available theoretical models with an adequate experimental setup. Measurements based on optical transition radiation (OTR) are a well-established technique for measurements of the transverse beam profile. However, in order to be suitable for halo measurements as well, the dynamic range of the final image acquisition system needs to be high, being able to cover at least five orders of magnitude in intensity changes. Here, the performance of a standard acquisition system as it is used in the CLIC test facility (CTF3) is compared to a step-by-step measurement with a small movable photo multiplier tube and an innovative camera system based on charge injection de...

  3. The CMS Beam Halo Monitor Detector System

    CERN Document Server

    CMS Collaboration

    2015-01-01

    A new Beam Halo Monitor (BHM) detector system has been installed in the CMS cavern to measure the machine-induced background (MIB) from the LHC. This background originates from interactions of the LHC beam halo with the final set of collimators before the CMS experiment and from beam gas interactions. The BHM detector uses the directional nature of Cherenkov radiation and event timing to select particles coming from the direction of the beam and to suppress those originating from the interaction point. It consists of 40 quartz rods, placed on each side of the CMS detector, coupled to UV sensitive PMTs. For each bunch crossing the PMT signal is digitized by a charge integrating ASIC and the arrival time of the signal is recorded. The data are processed in real time to yield a precise measurement of per-bunch-crossing background rate. This measurement is made available to CMS and the LHC, to provide real-time feedback on the beam quality and to improve the efficiency of data taking. In this talk we will describ...

  4. The CMS Beam Halo Monitor Detector System

    CERN Document Server

    Stifter, Kelly

    2015-01-01

    A new Beam Halo Monitor (BHM) detector system has been installed in the CMS cavern to measure the machine-induced background (MIB) from the LHC. This background originates from interactions of the LHC beam halo with the final set of collimators before the CMS experiment and from beam gas interactions. The BHM detector uses the directional nature of Cherenkov radiation and event timing to select particles coming from the direction of the beam and to supress those originating from the interaction point. It consists of 40 quartz rods, placed on each side of the CMS detector, coupled to UV sensitive PMTs. For each bunch crossing the PMT signal is digitized by a charge integrating ASIC and the arrival time of the signal is recorded. The data are processed in real time to yield a precise measurement of per-bunch-crossing background rate. This measurement is made available to CMS and the LHC, to provide real-time feedback on the beam quality and to improve the efficiency of data taking. In this talk we will descri...

  5. A 500 PARSEC HALO SURROUNDING THE GALACTIC GLOBULAR NGC 1851

    NARCIS (Netherlands)

    Olszewski, Edward W.; Saha, Abhijit; Knezek, Patricia; Subramaniam, Annapurni; de Boer, Thomas; Seitzer, Patrick

    2009-01-01

    Using imaging that shows 4 mag of main-sequence stars, we have discovered that the Galactic globular cluster NGC 1851 is surrounded by a halo that is visible from the tidal radius of 700 arcsec (41 pc) to more than 4500 arcsec (> 250 pc). This halo is symmetric and falls in density as a power law of

  6. Is the dark halo of our Galaxy spherical?

    NARCIS (Netherlands)

    Helmi, A

    2004-01-01

    It has been recently claimed that the confined structure of the debris from the Sagittarius dwarf implies that the dark matter halo of our Galaxy should be nearly spherical, in strong contrast with predictions from cold dark matter simulations, where dark haloes are found to have typical density

  7. Investigating Halo and Ceiling Effects in Student Evaluations of Instruction

    Science.gov (United States)

    Keeley, Jared W.; English, Taylor; Irons, Jessica; Henslee, Amber M.

    2013-01-01

    Many measurement biases affect student evaluations of instruction (SEIs). However, two have been relatively understudied: halo effects and ceiling/floor effects. This study examined these effects in two ways. To examine the halo effect, using a videotaped lecture, we manipulated specific teacher behaviors to be "good" or "bad"…

  8. Binary white dwarfs in the halo of the Milky Way

    NARCIS (Netherlands)

    van Oirschot, Pim; Nelemans, Gijs; Toonen, Silvia; Pols, Onno; Brown, Anthony G. A.; Helmi, Amina; Portegies Zwart, Simon

    Aims: We study single and binary white dwarfs in the inner halo of the Milky Way in order to learn more about the conditions under which the population of halo stars was born, such as the initial mass function (IMF), the star formation history, or the binary fraction. Methods: We simulate the

  9. Disk response to a lopsided halo potential (Jog 1997, 2002):

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. Disk response to a lopsided halo potential (Jog 1997, 2002):. consider small (few %) perturbation in potential. --- solve equations of motion using epicyclic theory. The symmetric disk potential = ψ_0 (R ) = Vc 2 ln R. and the perturbation halo potential = Vc 2 εlop cos φ ...

  10. THE COSMOGRID SIMULATION: STATISTICAL PROPERTIES OF SMALL DARK MATTER HALOS

    Energy Technology Data Exchange (ETDEWEB)

    Ishiyama, Tomoaki [Center for Computational Science, University of Tsukuba, 1-1-1, Tennodai, Tsukuba, Ibaraki 305-8577 (Japan); Rieder, Steven; Portegies Zwart, Simon [Sterrewacht Leiden, Leiden University, P.O. Box 9513, 2300-RA Leiden (Netherlands); Makino, Junichiro [Graduate School of Science and Engineering, Tokyo Institute of Technology (Japan); Groen, Derek [Centre for Computational Science, Department of Chemistry, University College London, 20 Gordon Street, London, WC1H 0AJ (United Kingdom); Nitadori, Keigo [RIKEN Advanced Institute for Computational Science (Japan); De Laat, Cees [Section System and Network Engineering, University of Amsterdam, Amsterdam (Netherlands); McMillan, Stephen [Department of Physics, Drexel University, Philadelphia, PA 19104 (United States); Hiraki, Kei [Department of Creative Informatics, Graduate School of Information Science and Technology, the University of Tokyo (Japan); Harfst, Stefan, E-mail: ishiyama@ccs.tsukuba.ac.jp [Center for Astronomy and Astrophysics, Technical University Berlin, Hardenbergstr. 36, D-10623 Berlin (Germany)

    2013-04-20

    We present the results of the ''Cosmogrid'' cosmological N-body simulation suites based on the concordance LCDM model. The Cosmogrid simulation was performed in a 30 Mpc box with 2048{sup 3} particles. The mass of each particle is 1.28 Multiplication-Sign 10{sup 5} M{sub Sun }, which is sufficient to resolve ultra-faint dwarfs. We found that the halo mass function shows good agreement with the Sheth and Tormen fitting function down to {approx}10{sup 7} M{sub Sun }. We have analyzed the spherically averaged density profiles of the three most massive halos which are of galaxy group size and contain at least 170 million particles. The slopes of these density profiles become shallower than -1 at the innermost radius. We also find a clear correlation of halo concentration with mass. The mass dependence of the concentration parameter cannot be expressed by a single power law, however a simple model based on the Press-Schechter theory proposed by Navarro et al. gives reasonable agreement with this dependence. The spin parameter does not show a correlation with the halo mass. The probability distribution functions for both concentration and spin are well fitted by the log-normal distribution for halos with the masses larger than {approx}10{sup 8} M{sub Sun }. The subhalo abundance depends on the halo mass. Galaxy-sized halos have 50% more subhalos than {approx}10{sup 11} M{sub Sun} halos have.

  11. The Cosmogrid Simulation: Statistical Properties of Small Dark Matter Halos

    Science.gov (United States)

    Ishiyama, Tomoaki; Rieder, Steven; Makino, Junichiro; Portegies Zwart, Simon; Groen, Derek; Nitadori, Keigo; de Laat, Cees; McMillan, Stephen; Hiraki, Kei; Harfst, Stefan

    2013-04-01

    We present the results of the "Cosmogrid" cosmological N-body simulation suites based on the concordance LCDM model. The Cosmogrid simulation was performed in a 30 Mpc box with 20483 particles. The mass of each particle is 1.28 × 105 M ⊙, which is sufficient to resolve ultra-faint dwarfs. We found that the halo mass function shows good agreement with the Sheth & Tormen fitting function down to ~107 M ⊙. We have analyzed the spherically averaged density profiles of the three most massive halos which are of galaxy group size and contain at least 170 million particles. The slopes of these density profiles become shallower than -1 at the innermost radius. We also find a clear correlation of halo concentration with mass. The mass dependence of the concentration parameter cannot be expressed by a single power law, however a simple model based on the Press-Schechter theory proposed by Navarro et al. gives reasonable agreement with this dependence. The spin parameter does not show a correlation with the halo mass. The probability distribution functions for both concentration and spin are well fitted by the log-normal distribution for halos with the masses larger than ~108 M ⊙. The subhalo abundance depends on the halo mass. Galaxy-sized halos have 50% more subhalos than ~1011 M ⊙ halos have.

  12. A two-point correlation function for Galactic halo stars

    NARCIS (Netherlands)

    Cooper, A. P.; Cole, S.; Frenk, C. S.; Helmi, A.

    2011-01-01

    We describe a correlation function statistic that quantifies the amount of spatial and kinematic substructure in the stellar halo. We test this statistic using model stellar halo realizations constructed from the Aquarius suite of six high-resolution cosmological N-body simulations, in combination

  13. Influence of halo doping profiles on MOS transistor mismatch

    NARCIS (Netherlands)

    Andricciola, P.; Tuinhout, H.

    2009-01-01

    Halo implants are used in modern CMOS technology to reduce the short channel effect. However, the lateral non-uniformity of the channel doping has been proven to degenerate the mismatch performance. With this paper we want to discuss the influence of the halo profile on MOS transistor mismatch. The

  14. A Hidden Radio Halo in the Galaxy Cluster A1682?

    Indian Academy of Sciences (India)

    High sensitivity observations of radio halos in galaxy clusters at frequencies ≤ 330 MHz are still relatively rare, and very little is known compared to the classical 1.4 GHz images. The few radio halos imaged down to 150–240 MHz show a considerable spread in size, morphology and spectral properties. All clusters ...

  15. Double folding model analysis of elastic scattering of halo nucleus ...

    Indian Academy of Sciences (India)

    features of halo nuclei largely affect the interaction with light and heavy targets at low bombarding energies and have created tremendous interest in the study of nuclear reac- tions. Elastic scattering is sensitive to the nature of the surface of nuclei and hence it is effective in studying halo nuclei. Pramana – J. Phys., Vol.

  16. The Connection between Radio Halos and Cluster Mergers and the ...

    Indian Academy of Sciences (India)

    We discuss the statistical properties of the radio halo population in galaxy clusters. Radio bi-modality is observed in galaxy clusters: a fraction of clusters host giant radio halos while a majority of clusters do not show evidence of diffuse cluster-scale radio emission. The radio bi-modality has a correspondence in terms of ...

  17. Factors important for women who breastfeed in public: a content analysis of review data from FeedFinder.

    Science.gov (United States)

    Simpson, Emma; Garbett, Andrew; Comber, Rob; Balaam, Madeline

    2016-10-24

    To examine how the breastfeeding experience is represented by users of FeedFinder (a mobile phone application for finding, reviewing and sharing places to breastfeed in public). Content analysis using FeedFinder database. FeedFinder, UK, September 2013-June 2015. Reviews obtained through FeedFinder over a period of 21 months were systematically coded using a conventional content analysis approach, average review scores were calculated for the rating criteria in FeedFinder (comfort, hygiene, privacy, baby facilities) and review texts were analysed for sentiment. We used data from Foursquare to describe the type of venues visited and cross-referenced the location of venues with the Indices of Multiple Deprivation. A total of 1757 reviews were analysed. Of all the reviews obtained, 80% of those were classified as positive, 15.4% were classified as neutral and 4.3% were classified as negative. Important factors that were discussed by women include facilities, service, level of privacy available and qualities of a venue. The majority of venues were classified as cafes (26.4%), shops (24.4%) and pubs (13.4%). Data on IMD were available for 1229 venues mapped within FeedFinder, 23% were located within the most deprived quintile and 16% were located in the least deprived quintile. Women create content that is positive and informative when describing their breastfeeding experience in public. Public health bodies and business owners have the potential to use the data from FeedFinder to impact on service provision. Further work is needed to explore the demographic differences that may help to tailor public health interventions aimed at increasing breastfeeding rates in the UK. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  18. MacSyFinder: a program to mine genomes for molecular systems with an application to CRISPR-Cas systems.

    Directory of Open Access Journals (Sweden)

    Sophie S Abby

    Full Text Available Biologists often wish to use their knowledge on a few experimental models of a given molecular system to identify homologs in genomic data. We developed a generic tool for this purpose.Macromolecular System Finder (MacSyFinder provides a flexible framework to model the properties of molecular systems (cellular machinery or pathway including their components, evolutionary associations with other systems and genetic architecture. Modelled features also include functional analogs, and the multiple uses of a same component by different systems. Models are used to search for molecular systems in complete genomes or in unstructured data like metagenomes. The components of the systems are searched by sequence similarity using Hidden Markov model (HMM protein profiles. The assignment of hits to a given system is decided based on compliance with the content and organization of the system model. A graphical interface, MacSyView, facilitates the analysis of the results by showing overviews of component content and genomic context. To exemplify the use of MacSyFinder we built models to detect and class CRISPR-Cas systems following a previously established classification. We show that MacSyFinder allows to easily define an accurate "Cas-finder" using publicly available protein profiles.MacSyFinder is a standalone application implemented in Python. It requires Python 2.7, Hmmer and makeblastdb (version 2.2.28 or higher. It is freely available with its source code under a GPLv3 license at https://github.com/gem-pasteur/macsyfinder. It is compatible with all platforms supporting Python and Hmmer/makeblastdb. The "Cas-finder" (models and HMM profiles is distributed as a compressed tarball archive as Supporting Information.

  19. Wanted: Scalable Tracers for Diffusion Measurements

    Science.gov (United States)

    2015-01-01

    Scalable tracers are potentially a useful tool to examine diffusion mechanisms and to predict diffusion coefficients, particularly for hindered diffusion in complex, heterogeneous, or crowded systems. Scalable tracers are defined as a series of tracers varying in size but with the same shape, structure, surface chemistry, deformability, and diffusion mechanism. Both chemical homology and constant dynamics are required. In particular, branching must not vary with size, and there must be no transition between ordinary diffusion and reptation. Measurements using scalable tracers yield the mean diffusion coefficient as a function of size alone; measurements using nonscalable tracers yield the variation due to differences in the other properties. Candidate scalable tracers are discussed for two-dimensional (2D) diffusion in membranes and three-dimensional diffusion in aqueous solutions. Correlations to predict the mean diffusion coefficient of globular biomolecules from molecular mass are reviewed briefly. Specific suggestions for the 3D case include the use of synthetic dendrimers or random hyperbranched polymers instead of dextran and the use of core–shell quantum dots. Another useful tool would be a series of scalable tracers varying in deformability alone, prepared by varying the density of crosslinking in a polymer to make say “reinforced Ficoll” or “reinforced hyperbranched polyglycerol.” PMID:25319586

  20. Scalable L-infinite coding of meshes.

    Science.gov (United States)

    Munteanu, Adrian; Cernea, Dan C; Alecu, Alin; Cornelis, Jan; Schelkens, Peter

    2010-01-01

    The paper investigates the novel concept of local-error control in mesh geometry encoding. In contrast to traditional mesh-coding systems that use the mean-square error as target distortion metric, this paper proposes a new L-infinite mesh-coding approach, for which the target distortion metric is the L-infinite distortion. In this context, a novel wavelet-based L-infinite-constrained coding approach for meshes is proposed, which ensures that the maximum error between the vertex positions in the original and decoded meshes is lower than a given upper bound. Furthermore, the proposed system achieves scalability in L-infinite sense, that is, any decoding of the input stream will correspond to a perfectly predictable L-infinite distortion upper bound. An instantiation of the proposed L-infinite-coding approach is demonstrated for MESHGRID, which is a scalable 3D object encoding system, part of MPEG-4 AFX. In this context, the advantages of scalable L-infinite coding over L-2-oriented coding are experimentally demonstrated. One concludes that the proposed L-infinite mesh-coding approach guarantees an upper bound on the local error in the decoded mesh, it enables a fast real-time implementation of the rate allocation, and it preserves all the scalability features and animation capabilities of the employed scalable mesh codec.

  1. RR Lyrae to build up the Galactic Halo

    Science.gov (United States)

    Fiorentino, Giuliana

    2015-08-01

    We compare the period and period-amplitude distributions for a sizeable sample of rrab in dwarfs (~1300stars) with those in the galactic halo (~14,000stars) and globular clusters (~1000stars). Field rrab show a significant change in their period distribution when moving from the inner (dg~14kpc) halo regions, suggesting that the halo formed from (at least) two dissimilar progenitors or events. Rrab in dwarfs-as observed today-do not appear to follow the pulsation properties shown by those in the galactic halo, nor do they have the same properties as rrls in globulars. Only massive and metal rich satellites likely have mainly contributed to the galactic halo formation, e.g. Sgr dSph.

  2. Binary white dwarfs in the halo of the Milky Way

    Science.gov (United States)

    van Oirschot, Pim; Nelemans, Gijs; Toonen, Silvia; Pols, Onno; Brown, Anthony G. A.; Helmi, Amina; Portegies Zwart, Simon

    2014-09-01

    Aims: We study single and binary white dwarfs in the inner halo of the Milky Way in order to learn more about the conditions under which the population of halo stars was born, such as the initial mass function (IMF), the star formation history, or the binary fraction. Methods: We simulate the evolution of low-metallicity halo stars at distances up to ~3 kpc using the binary population synthesis code SeBa. We use two different white dwarf cooling models to predict the present-day luminosities of halo white dwarfs. We determine the white dwarf luminosity functions (WDLFs) for eight different halo models and compare these with the observed halo WDLF of white dwarfs in the SuperCOSMOS Sky Survey. Furthermore, we predict the properties of binary white dwarfs in the halo and determine the number of halo white dwarfs that is expected to be observed with the Gaia satellite. Results: By comparing the WDLFs, we find that a standard IMF matches the observations more accurately than a top-heavy one, but the difference with a bottom-heavy IMF is small. A burst of star formation 13 Gyr ago fits slightly better than a star formation burst 10 Gyr ago and also slightly better than continuous star formation 10-13 Gyr ago. Gaia will be the first instument to constrain the bright end of the field halo WDLF, where contributions from binary WDs are considerable. Many of these will have He cores, of which a handful have atypical surface gravities (log g 0 in our standard model for WD cooling. These so called pre-WDs, if observed, can help us to constrain white dwarf cooling models and might teach us something about the fraction of halo stars that reside in binaries. Appendices are available in electronic form at http://www.aanda.org

  3. What sets the central structure of dark matter haloes?

    Science.gov (United States)

    Ogiya, Go; Hahn, Oliver

    2018-02-01

    Dark matter (DM) haloes forming near the thermal cut-off scale of the density perturbations are unique, since they are the smallest objects and form through monolithic gravitational collapse, while larger haloes contrastingly have experienced mergers. While standard cold dark matter (CDM) simulations readily produce haloes that follow the universal Navarro-Frenk-White (NFW) density profile with an inner slope, ρ ∝ r-α, with α = 1, recent simulations have found that when the free-streaming cut-off expected for the CDM model is resolved, the resulting haloes follow nearly power-law density profiles of α ∼ 1.5. In this paper, we study the formation of density cusps in haloes using idealized N-body simulations of the collapse of proto-haloes. When the proto-halo profile is initially cored due to particle free-streaming at high redshift, we universally find ∼r-1.5 profiles irrespective of the proto-halo profile slope outside the core and large-scale non-spherical perturbations. Quite in contrast, when the proto-halo has a power-law profile, then we obtain profiles compatible with the NFW shape when the density slope of the proto-halo patch is shallower than a critical value, αini ∼ 0.3, while the final slope can be steeper for αini ≳ 0.3. We further demonstrate that the r-1.5 profiles are sensitive to small-scale noise, which gradually drives them towards an inner slope of -1, where they become resilient to such perturbations. We demonstrate that the r-1.5 solutions are in hydrostatic equilibrium, largely consistent with a simple analytic model, and provide arguments that angular momentum appears to determine the inner slope.

  4. 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...... method that steers mining to few selected subspace clusters. Our novel steering technique reduces subspace processing by identifying and clustering promising subspaces and their combinations directly. Thereby, it narrows down the search space while maintaining accuracy. Thorough experiments on real...... and synthetic databases show that steering is efficient and scalable, with high quality results. For future work, our steering paradigm for density-based subspace clustering opens research potential for speeding up other subspace clustering approaches as well....

  5. Scalable Open Source Smart Grid Simulator (SGSim)

    DEFF Research Database (Denmark)

    Ebeid, Emad Samuel Malki; Jacobsen, Rune Hylsberg; Quaglia, Davide

    2017-01-01

    The future smart power grid will consist of an unlimited number of smart devices that communicate with control units to maintain the grid’s sustainability, efficiency, and balancing. In order to build and verify such controllers over a large grid, a scalable simulation environment is needed....... This paper presents an open source smart grid simulator (SGSim). The simulator is based on open source SystemC Network Simulation Library (SCNSL) and aims to model scalable smart grid applications. SGSim has been tested under different smart grid scenarios that contain hundreds of thousands of households...... and appliances. By using SGSim, different smart grid control strategies and protocols can be tested, validated and evaluated in a scalable environment....

  6. [Halos and multifocal intraocular lenses: origin and interpretation].

    Science.gov (United States)

    Alba-Bueno, F; Vega, F; Millán, M S

    2014-10-01

    To present the theoretical and experimental characterization of the halo in multifocal intraocular lenses (MIOL). The origin of the halo in a MIOL is the overlaying of 2 or more images. Using geometrical optics, it can be demonstrated that the diameter of each halo depends on the addition of the lens (ΔP), the base power (P(d)), and the diameter of the IOL that contributes to the «non-focused» focus. In the image plane that corresponds to the distance focus, the halo diameter (δH(d)) is given by: δH(d)=d(pn) ΔP/P(d), where d(pn) is the diameter of the IOL that contributes to the near focus. Analogously, in the near image plane the halo diameter (δH(n)) is: δH(n)=d(pd) ΔP/P(d), where d(pd) is the diameter of the IOL that contributes to the distance focus. Patients perceive halos when they see bright objects over a relatively dark background. In vitro, the halo can be characterized by analyzing the intensity profile of the image of a pinhole that is focused by each of the foci of a MIOL. A comparison has been made between the halos induced by different MIOL of the same base power (20D) in an optical bench. As predicted by theory, the larger the addition of the MIOL, the larger the halo diameter. For large pupils and with MIOL with similar aspheric designs and addition (SN6AD3 vs ZMA00), the apodized MIOL has a smaller halo diameter than a non-apodized one in distance vision, while in near vision the size is very similar, but the relative intensity is higher in the apodized MIOL. When comparing lenses with the same diffractive design, but with different spherical-aspheric base design (SN60D3 vs SN6AD3), the halo in distance vision of the spherical MIOL is larger, while in near vision the spherical IOL induces a smaller halo, but with higher intensity due to the spherical aberration of the distance focus in the near image. In the case of a trifocal-diffractive IOL (AT LISA 839MP) the most noticeable characteristic is the double-halo formation due to the 2 non

  7. From Digital Disruption to Business Model Scalability

    DEFF Research Database (Denmark)

    Nielsen, Christian; Lund, Morten; Thomsen, Peter Poulsen

    2017-01-01

    a long time to replicate, business model scalability can be cornered into four dimensions. In many corporate restructuring exercises and Mergers and Acquisitions there is a tendency to look for synergies in the form of cost reductions, lean workflows and market segments. However, this state of mind......This article discusses the terms disruption, digital disruption, business models and business model scalability. It illustrates how managers should be using these terms for the benefit of their business by developing business models capable of achieving exponentially increasing returns to scale...

  8. From Digital Disruption to Business Model Scalability

    DEFF Research Database (Denmark)

    Nielsen, Christian; Lund, Morten; Thomsen, Peter Poulsen

    2017-01-01

    as a response to digital disruption. A series of case studies illustrate that besides frequent existing messages in the business literature relating to the importance of creating agile businesses, both in growing and declining economies, as well as hard to copy value propositions or value propositions that take......This article discusses the terms disruption, digital disruption, business models and business model scalability. It illustrates how managers should be using these terms for the benefit of their business by developing business models capable of achieving exponentially increasing returns to scale...... will seldom lead to business model scalability capable of competing with digital disruption(s)....

  9. PEP-SiteFinder: a tool for the blind identification of peptide binding sites on protein surfaces.

    Science.gov (United States)

    Saladin, Adrien; Rey, Julien; Thévenet, Pierre; Zacharias, Martin; Moroy, Gautier; Tufféry, Pierre

    2014-07-01

    Peptide-protein interactions are important to many processes of life, particularly for signal transmission or regulatory mechanisms. When no information is known about the interaction between a protein and a peptide, it is of interest to propose candidate sites of interaction at the protein surface, to assist the design of biological experiments to probe the interaction, or to serve as a starting point for more focused in silico approaches. PEP-SiteFinder is a tool that will, given the structure of a protein and the sequence of a peptide, identify protein residues predicted to be at peptide-protein interface. PEP-SiteFinder relies on the 3D de novo generation of peptide conformations given its sequence. These conformations then undergo a fast blind rigid docking on the complete protein surface, and we have found, as the result of a benchmark over 41 complexes, that the best poses overlap to some extent the experimental patch of interaction for close to 90% complexes. In addition, PEP-SiteFinder also returns a propensity index we have found informative about the confidence of the prediction. The PEP-SiteFinder web server is available at http://bioserv.rpbs.univ-paris-diderot.fr/PEP-SiteFinder. © The Author(s) 2014. Published by Oxford University Press on behalf of Nucleic Acids Research.

  10. Content-Aware Scalability-Type Selection for Rate Adaptation of Scalable Video

    Directory of Open Access Journals (Sweden)

    Tekalp A Murat

    2007-01-01

    Full Text Available Scalable video coders provide different scaling options, such as temporal, spatial, and SNR scalabilities, where rate reduction by discarding enhancement layers of different scalability-type results in different kinds and/or levels of visual distortion depend on the content and bitrate. This dependency between scalability type, video content, and bitrate is not well investigated in the literature. To this effect, we first propose an objective function that quantifies flatness, blockiness, blurriness, and temporal jerkiness artifacts caused by rate reduction by spatial size, frame rate, and quantization parameter scaling. Next, the weights of this objective function are determined for different content (shot types and different bitrates using a training procedure with subjective evaluation. Finally, a method is proposed for choosing the best scaling type for each temporal segment that results in minimum visual distortion according to this objective function given the content type of temporal segments. Two subjective tests have been performed to validate the proposed procedure for content-aware selection of the best scalability type on soccer videos. Soccer videos scaled from 600 kbps to 100 kbps by the proposed content-aware selection of scalability type have been found visually superior to those that are scaled using a single scalability option over the whole sequence.

  11. SciFinder Scholar 2006: an empirical analysis of research topic query processing.

    Science.gov (United States)

    Wagner, A Ben

    2006-01-01

    Topical search queries in SciFinder Scholar are processed through an extensive set of natural language processing algorithms that greatly enhance the relevance and comprehensiveness of the search results. Little detailed documentation on these algorithms has been published. However, a careful examination of the highlighted hit terms coupled with a comparison of results from small variations in query language reveal much additional, useful information about these algorithms. An understanding of how these algorithms work can lead to better search results and explain many unexpected results, including differing hit counts for singular versus plural query words and phrases.

  12. Oblique Sounding of the Ionosphere by Means of an Ionosonde-Direction Finder with Chirp Signal

    Science.gov (United States)

    Vertogradov, G. G.; Uryadov, V. P.; Sklyarevsky, M. S.; Valov, V. A.

    2017-04-01

    We give a mathematical rationale, an algorithm, and hardware implementation for a multichannel ionosonde-direction finder with chirp signal. The results of experimental studies of twodimensional angle-frequency characteristics on the Cyprus—Rostov-on-Don meridional obliquesounding path are presented. It is shown that both regular (terminator-related) and irregular (caused by the passage of a traveling ionospheric disturbance through the propagation path) transverse (with respect to the propagation path) horizontal gradients of the electron number density lead to a deviation of the azimuth of the high-angle ray in the direction of the Ne gradient. The experimental data are compared with the simulation results.

  13. The inclusion of RPC only segments in the Barrel Muon Track Finder

    CERN Document Server

    CMS Collaboration

    2018-01-01

    On November 3, 2017 during the LHC fill 6360 and from the run number 306121 RPC-only segments were enable to trigger. In this document we show the impact of the RPC-only segments in the Barrel Muon Track Finder efficiency performance. The efficiency measurement was done with Tag and Probe cut and count following the Muon POG working point recommendations (tight ID and Particle Flow isolation requirements more details can be found in https://cds.cern.ch/record/2054113). The used dataset was ZMuMu corresponding to each period.

  14. Terrestrial Planet Finder Coronagraph 2005: Overview of Technology Development and System Design Studies

    Science.gov (United States)

    Ford, Virginia G.

    2005-01-01

    Technology research, design trades, and modeling and analysis guide the definition of a Terrestrial Planet Finder Coronagraph Mission that will search for and characterize earth-like planets around near-by stars. Operating in visible wavebands, this mission will use coronagraphy techniques to suppress starlight to enable capturing and imaging the reflected light from a planet orbiting in the habitable zone of its parent star. The light will be spectrally characterized to determine the presence of life-indicating chemistry in the planet atmosphere.

  15. Historic halo displays as weather indicator: Criteria and examples

    Science.gov (United States)

    Neuhäuser, Dagmar L.; Neuhäuser, Ralph

    2016-04-01

    There are numerous celestial signs reported in historic records, many of them refer to atmospheric ("sub-lunar") phenomena, such as ice halos and aurorae. In an interdisciplinary collaboration between astrophysics and cultural astronomy, we noticed that celestial observations including meteorological phenomena are often misinterpreted, mostly due to missing genuine criteria: especially ice crystal halos were recorded frequently in past centuries for religious reasons, but are mistaken nowadays often for other phenomena like aurorae. Ice halo displays yield clear information on humidity and temperature in certain atmospheric layers, and thereby indicate certain weather patterns. Ancient so-called rain makers used halo observations for weather forecast; e.g., a connection between certain halo displays and rain a few day later is statistically significant. Ice halos exist around sun and moon and are reported for both (they can stay for several days): many near, middle, and far eastern records from day- and night-time include such observations with high frequency. (Partly based on publications on halos by D.L. Neuhäuser & R. Neuhäuser, available at http://www.astro.uni-jena.de/index.php/terra-astronomy.html)

  16. Accurate mass and velocity functions of dark matter haloes

    Science.gov (United States)

    Comparat, Johan; Prada, Francisco; Yepes, Gustavo; Klypin, Anatoly

    2017-08-01

    N-body cosmological simulations are an essential tool to understand the observed distribution of galaxies. We use the MultiDark simulation suite, run with the Planck cosmological parameters, to revisit the mass and velocity functions. At redshift z = 0, the simulations cover four orders of magnitude in halo mass from ˜1011M⊙ with 8783 874 distinct haloes and 532 533 subhaloes. The total volume used is ˜515 Gpc3, more than eight times larger than in previous studies. We measure and model the halo mass function, its covariance matrix w.r.t halo mass and the large-scale halo bias. With the formalism of the excursion-set mass function, we explicit the tight interconnection between the covariance matrix, bias and halo mass function. We obtain a very accurate (Planck cosmology. Finally, we provide precise analytical fits of the Vmax maximum velocity function up to redshift z < 2.3 to push for the development of halo occupation distribution using Vmax. The data and the analysis code are made publicly available in the Skies and Universes data base.

  17. Chemical Cartography. I. A Carbonicity Map of the Galactic Halo

    Science.gov (United States)

    Lee, Young Sun; Beers, Timothy C.; Kim, Young Kwang; Placco, Vinicius; Yoon, Jinmi; Carollo, Daniela; Masseron, Thomas; Jung, Jaehun

    2017-02-01

    We present the first map of carbonicity, [C/Fe], for the halo system of the Milky Way, based on a sample of over 100,000 main-sequence turnoff stars with available spectroscopy from the Sloan Digital Sky Survey. This map, which explores distances up to 15 kpc from the Sun, reveals clear evidence for the dual nature of the Galactic halo, based on the spatial distribution of stellar carbonicity. The metallicity distribution functions of stars in the inner- and outer-halo regions of the carbonicity map reproduce those previously argued to arise from contributions of the inner- and outer-halo populations, with peaks at [Fe/H] = -1.5 and -2.2, respectively. From consideration of the absolute carbon abundances for our sample, A(C), we also confirm that the carbon-enhanced metal-poor (CEMP) stars in the outer-halo region exhibit a higher frequency of CEMP-no stars (those with no overabundances of heavy neutron-capture elements) than of CEMP-s stars (those with strong overabundances of elements associated with the s-process), whereas the stars in the inner-halo region exhibit a higher frequency of CEMP-s stars. We argue that the contrast in the behavior of the CEMP-no and CEMP-s fractions in these regions arises from differences in the mass distributions of the mini-halos from which the stars of the inner- and outer-halo populations formed, which gives rise in turn to the observed dichotomy of the Galactic halo.

  18. Chemical Cartography. I. A Carbonicity Map of the Galactic Halo

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Young Sun; Kim, Young Kwang [Department of Astronomy and Space Science, Chungnam National University, Daejeon 34134 (Korea, Republic of); Beers, Timothy C.; Placco, Vinicius; Yoon, Jinmi [Department of Physics and JINA Center for the Evolution of the Elements, University of Notre Dame, Notre Dame, IN 46556 (United States); Carollo, Daniela [Research School of Astronomy and Astrophysics, The Australian National University, Canberra, ACT 2611 (Australia); Masseron, Thomas [Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA (United Kingdom); Jung, Jaehun, E-mail: youngsun@cnu.ac.kr [Department of Astronomy, Space Science, and Geology, Chungnam National University, Daejeon 34134 (Korea, Republic of)

    2017-02-10

    We present the first map of carbonicity, [C/Fe], for the halo system of the Milky Way, based on a sample of over 100,000 main-sequence turnoff stars with available spectroscopy from the Sloan Digital Sky Survey. This map, which explores distances up to 15 kpc from the Sun, reveals clear evidence for the dual nature of the Galactic halo, based on the spatial distribution of stellar carbonicity. The metallicity distribution functions of stars in the inner- and outer-halo regions of the carbonicity map reproduce those previously argued to arise from contributions of the inner- and outer-halo populations, with peaks at [Fe/H] = −1.5 and −2.2, respectively. From consideration of the absolute carbon abundances for our sample, A (C), we also confirm that the carbon-enhanced metal-poor (CEMP) stars in the outer-halo region exhibit a higher frequency of CEMP-no stars (those with no overabundances of heavy neutron-capture elements) than of CEMP- s stars (those with strong overabundances of elements associated with the s -process), whereas the stars in the inner-halo region exhibit a higher frequency of CEMP- s stars. We argue that the contrast in the behavior of the CEMP-no and CEMP- s fractions in these regions arises from differences in the mass distributions of the mini-halos from which the stars of the inner- and outer-halo populations formed, which gives rise in turn to the observed dichotomy of the Galactic halo.

  19. Applying the ResFinder and VirulenceFinder web-services for easy identification of acquired antibiotic resistance and E. coli virulence genes in bacteriophage and prophage nucleotide sequences

    DEFF Research Database (Denmark)

    Kleinheinz, Kortine Annina; Joensen, Katrine Grimstrup; Larsen, Mette Voldby

    2014-01-01

    Extensive research is currently being conducted on the use of bacteriophages for applications in human medicine, agriculture and food manufacturing. However, phages are important vehicles of horisontal gene transfer and play a significant role in bacterial evolution. As a result, concern has been...... of these tools, ResFinder and VirulenceFinder, can be used to identify acquired antibiotic resistance and virulence genes in phage genomes of interest. The general applicability of the tools is demonstrated on data sets of 1,642 phage genomes and 1,442 predicted prophages....

  20. PartitionFinder 2: New Methods for Selecting Partitioned Models of Evolution for Molecular and Morphological Phylogenetic Analyses.

    Science.gov (United States)

    Lanfear, Robert; Frandsen, Paul B; Wright, April M; Senfeld, Tereza; Calcott, Brett

    2017-03-01

    PartitionFinder 2 is a program for automatically selecting best-fit partitioning schemes and models of evolution for phylogenetic analyses. PartitionFinder 2 is substantially faster and more efficient than version 1, and incorporates many new methods and features. These include the ability to analyze morphological datasets, new methods to analyze genome-scale datasets, new output formats to facilitate interoperability with downstream software, and many new models of molecular evolution. PartitionFinder 2 is freely available under an open source license and works on Windows, OSX, and Linux operating systems. It can be downloaded from www.robertlanfear.com/partitionfinder. The source code is available at https://github.com/brettc/partitionfinder. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  1. Scalable Detection and Isolation of Phishing

    NARCIS (Netherlands)

    Moreira Moura, Giovane; Pras, Aiko

    2009-01-01

    This paper presents a proposal for scalable detection and isolation of phishing. The main ideas are to move the protection from end users towards the network provider and to employ the novel bad neighborhood concept, in order to detect and isolate both phishing e-mail senders and phishing web

  2. Scalable Open Source Smart Grid Simulator (SGSim)

    DEFF Research Database (Denmark)

    Ebeid, Emad Samuel Malki; Jacobsen, Rune Hylsberg; Stefanni, Francesco

    2017-01-01

    . This paper presents an open source smart grid simulator (SGSim). The simulator is based on open source SystemC Network Simulation Library (SCNSL) and aims to model scalable smart grid applications. SGSim has been tested under different smart grid scenarios that contain hundreds of thousands of households...

  3. Realization of a scalable airborne radar

    NARCIS (Netherlands)

    Halsema, D. van; Jongh, R.V. de; Es, J. van; Otten, M.P.G.; Vermeulen, B.C.B.; Liempt, L.J. van

    2008-01-01

    Modern airborne ground surveillance radar systems are increasingly based on Active Electronically Scanned Array (AESA) antennas. Efficient use of array technology and the need for radar solutions for various airborne platforms, manned and unmanned, leads to the design of scalable radar systems. The

  4. Scalable Domain Decomposed Monte Carlo Particle Transport

    Energy Technology Data Exchange (ETDEWEB)

    O' Brien, Matthew Joseph [Univ. of California, Davis, CA (United States)

    2013-12-05

    In this dissertation, we present the parallel algorithms necessary to run domain decomposed Monte Carlo particle transport on large numbers of processors (millions of processors). Previous algorithms were not scalable, and the parallel overhead became more computationally costly than the numerical simulation.

  5. Subjective comparison of temporal and quality scalability

    DEFF Research Database (Denmark)

    Korhonen, Jari; Reiter, Ulrich; You, Junyong

    2011-01-01

    and quality scalability. The practical experiments with low resolution video sequences show that in general, distortion is a more crucial factor for the perceived subjective quality than frame rate. However, the results also depend on the content. Moreover,, we discuss the role of other different influence...

  6. Stellar halos: a rosetta stone for galaxy formation and cosmology

    Science.gov (United States)

    Inglis Read, Justin

    2015-08-01

    Stellar halos make up about a percent of the total stellar mass in galaxies. Yet their old age and long phase mixing times make them living fossil records of galactic history. In this talk, I review the latest simulations of structure formation in our standard Lambda Cold Dark Matter cosmology. I discuss the latest predictions for stellar halos and the relationship between the stellar halo light and the underlying dark matter. Finally, I discuss how these simulations compare to observations of the Milky Way and Andromeda and, ultimately, what this means for our cosmological model and the formation history of the Galaxy.

  7. Peripheral cholangiocarcinoma : Radiologic significance of hypoechoic halo sign on sonography

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Young Eok; Moon, Haeng Jin; Lee, Eun Ja; Ahn, In Oak [Gyeong Sang National Univ., College of Medicine, Chinju (Korea, Republic of)

    2001-12-01

    To determine the prevalence and characteristics of the hypoechoic halo sign in peripheral cholangiocarcinoma. Seventeen sonograms of 17 patients with peripheral cholangiocarcinoma histologically proven by either percutaneous needle biopsy (n=16) or surgical biopsy (n=1) were retrospectively reviewed. The size, margin, homogeneity and internal echogenicity of the masses as well as their peritumoral ductal dilatation and intratumoral calcification were ascertained, and the presence of a hypoechoic halo, and if present, its thickness and type, were also determined. We arbitrarily defined a 'thin' and 'thick' halo respectively, as one with a thickness less than of less than 3 mm, and 3 mm or more, and classified halos as 'intratumoral', 'extratumoral', or 'mixed'. Tumor diameter ranged from 4 to 13.5 (mean,7.3)cm, and the margin was well-defined in 15 cases (smooth: n=2; lobulated: n=13) and irregular in two. Echogenicity was slightly heterogeneous in 11 cases, severely heterogeneous in three, and hemogeneous in three, while the central portion was hyperechoic in eight cases, isoechoic in seven, and hypoechoic in only two. A hypoechoic halo was detected in 10 of 15 tumors (67%) with isoechoic centers. In evaluating the halo, two cases in which the mass was hypoechoic were excluded. All ten hypoechoic halos were at least 3 (range, 4-13; mean, 8.3) mm thick; in two cases the presence of a halo was equivocal, and in three there was no halo. Eight of ten halos were the mixed type, two were intratumoral, and none were extratumoral. Peritumoral ductal dilatation was seen in four cases (24%), but no internal calcification was observed. US showed that the margins of peripheral cholangiocarcinomas were mostly well-defined and smooth (12%) or lobulated (76%), and that masses were mainly heterogeneous (64%) A hypoechoic halo, which in all cases was thick and in 80% of cases was mixed, was noted in 67% of tumors with a hyper (47

  8. Evolution of Southern Hemisphere spring air masses observed by HALOE

    Science.gov (United States)

    Pierce, R. Bradley; Grose, William L.; Russell, James M., III; Tuck, Adrian F.

    1994-01-01

    The evolution of Southern Hemisphere air masses observed by the Halogen Occultation Experiment (HALOE) during September 21 through October 15, 1992, is investigated using isentropic trajectories computed from United Kingdom Meteorological Office (UKMO) assimilated winds and temperatures. Maps of constituent concentrations are obtained by accumulation of air masses from previous HALOE occultations. Lagged correlations between initial and subsequent HALOE observations of the same air mass are used to validate the air mass trajectories. High correlations are found for lag times as large as 10 days. Frequency distributions of the air mass constituent concentrations are used to examine constituent distributions in and around the Southern Hemisphere polar vortex.

  9. Connecting Galaxies, Halos, and Star Formation Rates Across Cosmic Time

    Energy Technology Data Exchange (ETDEWEB)

    Conroy, Charlie; Wechsler, Risa H.

    2008-06-02

    A simple, observationally-motivated model is presented for understanding how halo masses, galaxy stellar masses, and star formation rates are related, and how these relations evolve with time. The relation between halo mass and galaxy stellar mass is determined by matching the observed spatial abundance of galaxies to the expected spatial abundance of halos at multiple epochs--i.e. more massive galaxies are assigned to more massive halos at each epoch. This 'abundance matching' technique has been shown previously to reproduce the observed luminosity- and scale-dependence of galaxy clustering over a range of epochs. Halos at different epochs are connected by halo mass accretion histories estimated from N-body simulations. The halo-galaxy connection at fixed epochs in conjunction with the connection between halos across time provides a connection between observed galaxies across time. With approximations for the impact of merging and accretion on the growth of galaxies, one can then directly infer the star formation histories of galaxies as a function of stellar and halo mass. This model is tuned to match both the observed evolution of the stellar mass function and the normalization of the observed star formation rate--stellar mass relation to z {approx} 1. The data demands, for example, that the star formation rate density is dominated by galaxies with M{sub star} {approx} 10{sup 10.0-10.5} M{sub {circle_dot}} from 0 < z < 1, and that such galaxies over these epochs reside in halos with M{sub vir} {approx} 10{sup 11.5-12.5} M{sub {circle_dot}}. The star formation rate--halo mass relation is approximately Gaussian over the range 0 < z < 1 with a mildly evolving mean and normalization. This model is then used to shed light on a number of issues, including (1) a clarification of 'downsizing', (2) the lack of a sharp characteristic halo mass at which star formation is truncated, and (3) the dominance of star formation over merging to the stellar

  10. Vaccine Finder

    Science.gov (United States)

    ... list . Showing availability for 25,354 locations. Influenza Vaccine Recommended for everyone greater than or equal to ... which one may be right for you! Flu Vaccines Protects again influenza, commonly called flu, a respiratory ...

  11. Fat Finders

    Science.gov (United States)

    Christie-Blick, Kottie

    2006-01-01

    Every day the media bombards the nation with concern over childhood obesity. More American children than ever before are developing health problems related to their eating habits and lack of exercise. The classroom is the perfect place to deal with this national crisis by speaking directly to the children. If children could become more aware of…

  12. The immitigable nature of assembly bias: the impact of halo definition on assembly bias

    Science.gov (United States)

    Villarreal, Antonio S.; Zentner, Andrew R.; Mao, Yao-Yuan; Purcell, Chris W.; van den Bosch, Frank C.; Diemer, Benedikt; Lange, Johannes U.; Wang, Kuan; Campbell, Duncan

    2017-11-01

    Dark matter halo clustering depends not only on halo mass, but also on other properties such as concentration and shape. This phenomenon is known broadly as assembly bias. We explore the dependence of assembly bias on halo definition, parametrized by spherical overdensity parameter, Δ. We summarize the strength of concentration-, shape-, and spin-dependent halo clustering as a function of halo mass and halo definition. Concentration-dependent clustering depends strongly on mass at all Δ. For conventional halo definitions (Δ ˜ 200 - 600 m), concentration-dependent clustering at low mass is driven by a population of haloes that is altered through interactions with neighbouring haloes. Concentration-dependent clustering can be greatly reduced through a mass-dependent halo definition with Δ ˜ 20 - 40 m for haloes with M200 m ≲ 1012 h-1M⊙. Smaller Δ implies larger radii and mitigates assembly bias at low mass by subsuming altered, so-called backsplash haloes into now larger host haloes. At higher masses (M200 m ≳ 1013 h-1M⊙) larger overdensities, Δ ≳ 600 m, are necessary. Shape- and spin-dependent clustering are significant for all halo definitions that we explore and exhibit a relatively weaker mass dependence. Generally, both the strength and the sense of assembly bias depend on halo definition, varying significantly even among common definitions. We identify no halo definition that mitigates all manifestations of assembly bias. A halo definition that mitigates assembly bias based on one halo property (e.g. concentration) must be mass dependent. The halo definitions that best mitigate concentration-dependent halo clustering do not coincide with the expected average splashback radii at fixed halo mass.

  13. UWB antenna system for mobile bearing finder of radio and television stations

    Directory of Open Access Journals (Sweden)

    Kyryliuk V.A.

    2016-04-01

    Full Text Available This research discusses the problem of development and manufacturing of the ultra-wideband (UWB antenna element and antenna system on the basis of such element for mobile bearing finder of radio and television signals with the use of direction bearing quasi Doppler method. Due to the research results the mobile ultra-wideband antenna system was suggested. Its elements are new ultra-wideband emitters, which can belong to disco-cone antenna class. Ultra-wideband emitters are provided by foil form of the antenna element. The round function of the AS element, obtained by theoretical modeling and confirmed by practical experiments, has an exponential form. The fifth degree polynomial provides the required accuracy approximation. The combination of the radiator elements, their alignment and soldering is carried out by means of specially designed equipment. Checking of the transmitter parameter is done by proportional constant measuring of standing wave, which takes the meaning less than three values in the frequency range from 95 to 900 MHz. This satisfies the requirements of the ultra-wideband antenna direction bearing finder sources of radio signals. The basic parameters and design features of AS are presented.

  14. Is commercially available point finder accurate and reliable in detecting active auricular acupuncture points?

    Science.gov (United States)

    Wang, Shu-Ming; Maranets, Inna; Lin, Eric C; DeZinno, Peggy

    2012-09-01

    This study was done to determine the specificity and sensitivity of a commercial Pointer Plus (Point finder) in detecting a region of low skin resistance on the ear. This was a prospective blinded study. The study was done at the Yale New Haven Hospital, New Haven, CT. The subjects were men and women who work at Yale New Haven Hospital. There were no interventions. Correlations were made between self-reported musculoskeletal pain and the detection of low skin resistance on the ear. The positive predictive value for Pointer Plus detecting low skin resistance correlating to the neck region of French auricular map is 0.76 (76%). The positive predictive value for Pointer Plus to detect low skin resistance area correlating to the low back region of French auricular map is 0.25. The positive predictive value for Pointer Plus in detecting any low in skin resistance on the external auricles in patients who complained of more than two musculoskeletal pains is 0.29. The specificity and sensitivity of a commercial Pointer Plus (point finder) in detecting a region of low skin resistance on the ear being unreliable, depending on the correlating area based on a published auricular map. Additional assessments are needed to support the clinical practice.

  15. PPI finder: a mining tool for human protein-protein interactions.

    Directory of Open Access Journals (Sweden)

    Min He

    Full Text Available BACKGROUND: The exponential increase of published biomedical literature prompts the use of text mining tools to manage the information overload automatically. One of the most common applications is to mine protein-protein interactions (PPIs from PubMed abstracts. Currently, most tools in mining PPIs from literature are using co-occurrence-based approaches or rule-based approaches. Hybrid methods (frame-based approaches by combining these two methods may have better performance in predicting PPIs. However, the predicted PPIs from these methods are rarely evaluated by known PPI databases and co-occurred terms in Gene Ontology (GO database. METHODOLOGY/PRINCIPAL FINDINGS: We here developed a web-based tool, PPI Finder, to mine human PPIs from PubMed abstracts based on their co-occurrences and interaction words, followed by evidences in human PPI databases and shared terms in GO database. Only 28% of the co-occurred pairs in PubMed abstracts appeared in any of the commonly used human PPI databases (HPRD, BioGRID and BIND. On the other hand, of the known PPIs in HPRD, 69% showed co-occurrences in the literature, and 65% shared GO terms. CONCLUSIONS: PPI Finder provides a useful tool for biologists to uncover potential novel PPIs. It is freely accessible at http://liweilab.genetics.ac.cn/tm/.

  16. BosFinder: a novel pre-microRNA gene prediction algorithm in Bos taurus.

    Science.gov (United States)

    Sadeghi, B; Ahmadi, H; Azimzadeh-Jamalkandi, S; Nassiri, M R; Masoudi-Nejad, A

    2014-08-01

    MicroRNAs (miRNAs) are small non-coding RNAs that modulate gene expression transcriptionally (transcriptional activation or inactivation) and/or post-transcriptionally (translation inhibition or degradation of their target mRNAs). This phenomenon has significant roles in growth and developmental processes in plants and animals. Bos taurus is one of the most important livestock animals, having great importance in food and economical sciences and industries. However, limited information is available on Bos taurus constituent miRNAs because its whole genome assembly has been only recently published. Therefore, computational methods have been essential tools in miRNA gene prediction and discovery. Among these, machine-learning-based approaches are used to characterize genome scale pre-miRNAs from expressed sequence tags (ESTs). In this study, a support vector machine model was used to classify 33 structural and thermodynamic features of pre-miRNA genes. Public bovine EST data were obtained from different tissues in various developmental stages. A new algorithm, called BosFinder, was developed to identify and annotate the whole genome's derived pre-miRNAs. We found 18 776 highly potential pre-miRNA sequences. This is the first genome survey report of Bos taurus based on a machine-learning method for pre-miRNA gene finding. The bosfinder program is freely available at http://lbb.ut.ac.ir/Download/LBBsoft/BosFinder/. © 2014 Stichting International Foundation for Animal Genetics.

  17. Reconstruction of halo power spectrum from redshift-space galaxy distribution: cylinder-grouping method and halo exclusion effect

    Science.gov (United States)

    Okumura, Teppei; Takada, Masahiro; More, Surhud; Masaki, Shogo

    2017-07-01

    The peculiar velocity field measured by redshift-space distortions (RSD) in galaxy surveys provides a unique probe of the growth of large-scale structure. However, systematic effects arise when including satellite galaxies in the clustering analysis. Since satellite galaxies tend to reside in massive haloes with a greater halo bias, the inclusion boosts the clustering power. In addition, virial motions of the satellite galaxies cause a significant suppression of the clustering power due to non-linear RSD effects. We develop a novel method to recover the redshift-space power spectrum of haloes from the observed galaxy distribution by minimizing the contamination of satellite galaxies. The cylinder-grouping method (CGM) we study effectively excludes satellite galaxies from a galaxy sample. However, we find that this technique produces apparent anisotropies in the reconstructed halo distribution over all the scales which mimic RSD. On small scales, the apparent anisotropic clustering is caused by exclusion of haloes within the anisotropic cylinder used by the CGM. On large scales, the misidentification of different haloes in the large-scale structures, aligned along the line of sight, into the same CGM group causes the apparent anisotropic clustering via their cross-correlation with the CGM haloes. We construct an empirical model for the CGM halo power spectrum, which includes correction terms derived using the CGM window function at small scales as well as the linear matter power spectrum multiplied by a simple anisotropic function at large scales. We apply this model to a mock galaxy catalogue at z = 0.5, designed to resemble Sloan Digital Sky Survey-III Baryon Oscillation Spectroscopic Survey (BOSS) CMASS galaxies, and find that our model can predict both the monopole and quadrupole power spectra of the host haloes up to k < 0.5 {{h Mpc^{-1}}} to within 5 per cent.

  18. On the galaxy-halo connection in the EAGLE simulation

    Science.gov (United States)

    Desmond, Harry; Mao, Yao-Yuan; Wechsler, Risa H.; Crain, Robert A.; Schaye, Joop

    2017-10-01

    Empirical models of galaxy formation require assumptions about the correlations between galaxy and halo properties. These may be calibrated against observations or inferred from physical models such as hydrodynamical simulations. In this Letter, we use the EAGLE simulation to investigate the correlation of galaxy size with halo properties. We motivate this analysis by noting that the common assumption of angular momentum partition between baryons and dark matter in rotationally supported galaxies overpredicts both the spread in the stellar mass-size relation and the anticorrelation of size and velocity residuals, indicating a problem with the galaxy-halo connection it implies. We find the EAGLE galaxy population to perform significantly better on both statistics, and trace this success to the weakness of the correlations of galaxy size with halo mass, concentration and spin at fixed stellar mass. Using these correlations in empirical models will enable fine-grained aspects of galaxy scalings to be matched.

  19. Impact of Neutrinos on Dark Matter Halo Environment

    Science.gov (United States)

    Court, Travis; Villaescusa-Navarro, Francisco

    2018-01-01

    The spatial clustering of galaxies is commonly used to infer the shape of the matter power spectrum and therefore to place constraints on the value of the cosmological parameters. In order to extract the maximum information from galaxy surveys it is required to provide accurate theoretical predictions. The first step to model galaxy clustering is to understand the spatial distribution of the structures where they reside: dark matter halos. I will show that the clustering of halos does not depend only on mass, but on other quantities like local matter overdensity. I will point out that halo clustering is also sensitive to the local overdensity of the cosmic neutrino background. I will show that splitting halos according to neutrino overdensity induces a very large scale-dependence bias, an effect that may lead to a new technique to constraint the sum of the neutrino masses.

  20. Visibility of stars, halos, and rainbows during solar eclipses.

    Science.gov (United States)

    Können, Gunther P; Hinz, Claudia

    2008-12-01

    The visibility of stars, planets, diffraction coronas, halos, and rainbows during the partial and total phases of a solar eclipse is studied. The limiting magnitude during various stages of the partial phase is presented. The sky radiance during totality with respect to noneclipse conditions is revisited and found to be typically 1/4000. The corresponding limiting magnitude is +3.5. At totality, the signal-to-background ratio of diffraction coronas, halos, and rainbows has dropped by a factor of 250. It is found that diffraction coronas around the totally eclipsed Sun may nevertheless occur. Analyses of lunar halo observations during twilight indicate that bright halo displays may also persist during totality. Rainbows during totality seem impossible.

  1. Planetary nebulae as kinematic tracers of galaxy stellar halos

    Science.gov (United States)

    Coccato, Lodovico

    2017-10-01

    The kinematic and dynamical properties of galaxy stellar halos are difficult to measure because of the faint surface brightness that characterizes these regions. Spiral galaxies can be probed using the radio Hi emission; on the contrary, early-type galaxies contain less gas, therefore alternative kinematic tracers need to be used. Planetary nebulae (PNe) can be easily detected far out in the halo thanks to their bright emission lines. It is therefore possible to map the halo kinematics also in early-type galaxies, typically out to 5 effective radii or beyond. Thanks to the recent spectroscopic surveys targeting extra-galactic PNe, we can now rely on a few tens of galaxies where the kinematics of the stellar halos are measured. Here, I will review the main results obtained in this field in the last decades.

  2. Halo performance on low light level image intensifiers

    Science.gov (United States)

    Cui, Dongxu; Ren, Ling; Chang, Benkang; Shi, Feng; Shi, Jifang; Qian, Yunsheng; Wang, Honggang; Zhang, Junju

    To analyze the formation mechanism of the halo on low light level image intensifiers and the influencing factors on the halo size, a halo tester has been designed. Under the illumination between 10-2 lx and 10-4 lx, we use the tester to collect a 0.1922 mm hole image directly with CoolSNAPK4 charge-coupled device (CCD) in a darkroom. The practical measurement result shows that the amplification ratio is 343.4. Then we put the super second and third generation image intensifiers after the hole, and the halo sizes of the hole images on the screens are determined as 0.2388 and 0.5533 mm respectively. The results are helpful to improve the quality of the low light level image intensifiers.

  3. Summary of the 2014 Beam-Halo Monitoring Workshop

    Energy Technology Data Exchange (ETDEWEB)

    Fisher, Alan

    2015-09-25

    Understanding and controlling beam halo is important for high-intensity hadron accelerators, for high-brightness electron linacs, and for low-emittance light sources. This can only be achieved by developing suitable diagnostics. The main challenge faced by such instrumentation is the high dynamic range needed to observe the halo in the presence of an intense core. In addition, measurements must often be made non-invasively. This talk summarizes the one-day workshop on Beam-Halo Monitoring that was held at SLAC on September 19 last year, immediately following IBIC 2014 in Monterey. Workshop presentations described invasive techniques using wires, screens, or crystal collimators, and non-invasive measurements with gas or scattered electrons. Talks on optical methods showed the close links between observing halo and astronomical problems like observing the solar corona or directly observing a planet orbiting another star.

  4. UARS Halogen Occultation Experiment (HALOE) Level 3AT V001

    Data.gov (United States)

    National Aeronautics and Space Administration — The Halogen Occultation Experiment (HALOE) Level 3AT data product consists of daily vertical profiles of temperature, aerosol extinction and concentrations of HCl,...

  5. Revisiting Scaling Relations for Giant Radio Halos in Galaxy Clusters

    Science.gov (United States)

    Cassano, R.; Ettori, S.; Brunetti, G.; Giacintucci, S.; Pratt, G. W.; Venturi, T.; Kale, R.; Dolag, K.; Markevitch, Maxim L.

    2013-01-01

    Many galaxy clusters host megaparsec-scale radio halos, generated by ultrarelativistic electrons in the magnetized intracluster medium. Correlations between the synchrotron power of radio halos and the thermal properties of the hosting clusters were established in the last decade, including the connection between the presence of a halo and cluster mergers. The X-ray luminosity and redshift-limited Extended GMRT Radio Halo Survey provides a rich and unique dataset for statistical studies of the halos. We uniformly analyze the radio and X-ray data for the GMRT cluster sample, and use the new Planck Sunyaev-Zel'dovich (SZ) catalog to revisit the correlations between the power of radio halos and the thermal properties of galaxy clusters. We find that the radio power at 1.4 GHz scales with the cluster X-ray (0.1-2.4 keV) luminosity computed within R(sub 500) as P(sub 1.4) approx. L(2.1+/-0.2) - 500). Our bigger and more homogenous sample confirms that the X-ray luminous (L(sub 500) > 5 × 10(exp 44) erg/s)) clusters branch into two populations-radio halos lie on the correlation, while clusters without radio halos have their radio upper limits well below that correlation. This bimodality remains if we excise cool cores from the X-ray luminosities. We also find that P(sub 1.4) scales with the cluster integrated SZ signal within R(sub 500), measured by Planck, as P(sub 1.4) approx. Y(2.05+/-0.28) - 500), in line with previous findings. However, contrary to previous studies that were limited by incompleteness and small sample size, we find that "SZ-luminous" Y(sub 500) > 6×10(exp -5) Mpc(exp 2) clusters show a bimodal behavior for the presence of radio halos, similar to that in the radio-X-ray diagram. Bimodality of both correlations can be traced to clusters dynamics, with radio halos found exclusively in merging clusters. These results confirm the key role of mergers for the origin of giant radio halos, suggesting that they trigger the relativistic particle acceleration.

  6. Vaporization in comets - The icy grain halo of Comet West

    Science.gov (United States)

    Ahearn, M. F.; Cowan, J. J.

    1980-01-01

    The variation with heliocentric distance of the production rates of various species in Comet West (1975n = 1976 VI) is explained with a cometary model consisting of a CO2 dominated nucleus plus a halo of icy grains of H2O or clathrate hydrate. It is concluded that the parents of CN and C3 are released primarily from the nucleus but that the parent of C2 is released primarily from the halo of icy grains.

  7. Integrated Marketing Communications (IMC) Di PT Halo Rumah Bernyanyi

    OpenAIRE

    Rismayanti, Rebekka

    2016-01-01

    : This research aims to describe the effectiveness of Integrated Marketing Communication (IMC) in PT Halo Rumah Bernyanyi which, from the perspective of marketing strategy, could be studied by analyzing the segmentation, targeting, and positioning. Using case-study method with in-depth interview, the result shows that the implementation of IMC at PT Halo Rumah Bernyayi is arranged in one single strategy and tend to neglect the complexities of running multi-brand family karaoke-house. This con...

  8. Integrated Marketing Communications (IMC) di PT Halo Rumah Bernyanyi

    OpenAIRE

    Rebekka Rismayanti

    2017-01-01

    Abstract: This research aims to describe the effectiveness of Integrated Marketing Communication (IMC) in PT Halo Rumah Bernyanyi which, from the perspective of marketing strategy, could be studied by analyzing the segmentation, targeting, and positioning. Using case-study method with in-depth interview, the result shows that the implementation of IMC at PT Halo Rumah Bernyayi is arranged in one single strategy and tend to neglect the complexities of running multi-brand family karaoke-house. ...

  9. Non-Gaussianity and Excursion Set Theory: Halo Bias

    Energy Technology Data Exchange (ETDEWEB)

    Adshead, Peter [Enrico Fermi Institute, Univ. of Chicago, IL (United States); Baxter, Eric J. [Univ. of Chicago, Chicago, IL (United States); Dodelson, Scott [Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States); Lidz, Adam [Univ. of Pennsylvania, Philadelphia, PA (United States)

    2012-09-01

    We study the impact of primordial non-Gaussianity generated during inflation on the bias of halos using excursion set theory. We recapture the familiar result that the bias scales as $k^{-2}$ on large scales for local type non-Gaussianity but explicitly identify the approximations that go into this conclusion and the corrections to it. We solve the more complicated problem of non-spherical halos, for which the collapse threshold is scale dependent.

  10. MD 1691: Active halo control using tune ripple at injection

    CERN Document Server

    Garcia Morales, Hector; Bruce, Roderik; Redaelli, Stefano; Fitterer, Miriam; Fiascaris, Maria; Nisbet, David; Thiesen, Hugues; Valentino, Gianluca; Xu, Chen; CERN. Geneva. ATS Department

    2017-01-01

    In this MD we performed halo excitation through tune ripple. This consists in an excitation that introduces new resonance sidebands around the existing resonance lines. In presence of sufficient detuning with amplitude, these sidebands can in principle affect only the dynamics of the halo particles at large amplitudes. Tune ripple was induced through a current modulation of the warm trim quadrupoles in IR7. This is the first time this method is experimentally tested at the LHC.

  11. Nano-mechanics of HaloTag Tethers

    OpenAIRE

    Popa, Ionel; Berkovich, Ronen; Alegre-Cebollada, Jorge; Badilla, Carmen L.; Rivas-Pardo, Jaime Andres; Taniguchi, Yukinori; Kawakami, Masaru; Fernandez, Julio M.

    2013-01-01

    The active site of the Haloalkane Dehydrogenase (HaloTag) enzyme can be covalently attached to a chloroalkane ligand providing a mechanically strong tether, resistant to large pulling forces. Here we demonstrate the covalent tethering of protein L and I27 polyproteins between an AFM cantilever and a glass surface using HaloTag anchoring at one end, and thiol chemistry at the other end. Covalent tethering is unambiguously confirmed by the observation of full length polyprotein unfolding, combi...

  12. Two Stellar Components in the Halo of the Milky Way

    Science.gov (United States)

    2007-12-13

    distributed throughout the primordial interstellar medium by stellar winds and supernovae . Previous work has provided evidence that the halo of the Milky...the number of stars), for samples in which a counter-rotating halo has been claimed, ordered by sample size. The samples listed in the first column...sample by the authors are listed in the third column (see original papers for details). The method of analysis used for each determination is listed : F&W

  13. The globular cluster-dark matter halo connection

    Science.gov (United States)

    Boylan-Kolchin, Michael

    2017-12-01

    I present a simple phenomenological model for the observed linear scaling of the stellar mass in old globular clusters (GCs) with $z=0$ halo mass in which the stellar mass in GCs scales linearly with progenitor halo mass at $z=6$ above a minimum halo mass for GC formation. This model reproduces the observed $M_{\\rm GCs}-M_{\\rm halo}$ relation at $z=0$ and results in a prediction for the minimum halo mass at $z=6$ required for hosting one GC: $M_{\\rm min}(z=6)=1.07 \\times 10^9\\,M_{\\odot}$. Translated to $z=0$, the mean threshold mass is $M_{\\rm halo}(z=0) \\approx 2\\times 10^{10}\\,M_{\\odot}$. I explore the observability of GCs in the reionization era and their contribution to cosmic reionization, both of which depend sensitively on the (unknown) ratio of GC birth mass to present-day stellar mass, $\\xi$. Based on current detections of $z \\gtrsim 6$ objects with $M_{1500} 10$ are strongly disfavored; this, in turn, has potentially important implications for GC formation scenarios. Even for low values of $\\xi$, some observed high-$z$ galaxies may actually be GCs, complicating estimates of reionization-era galaxy ultraviolet luminosity functions and constraints on dark matter models. GCs are likely important reionization sources if $5 \\lesssim \\xi \\lesssim 10$. I also explore predictions for the fraction of accreted versus in situ GCs in the local Universe and for descendants of systems at the halo mass threshold of GC formation (dwarf galaxies). An appealing feature of the model presented here is the ability to make predictions for GC properties based solely on dark matter halo merger trees.

  14. The abundance and environment of dark matter haloes

    Science.gov (United States)

    Metuki, Ofer; Libeskind, Noam I.; Hoffman, Yehuda

    2016-07-01

    An open question in cosmology and the theory of structure formation is to what extent does environment affect the properties of galaxies and haloes. The present paper aims at shedding light on this problem. The paper focuses on the analysis of a dark matter only simulation and it addresses the issue of how the environment affects the abundance of haloes, which are assigned four attributes: their virial mass, an ambient density calculated with an aperture that scales with Rvir (ΔM), a fixed-aperture (ΔR) ambient density, and a cosmic web classification (i.e. voids, sheets, filaments, and knots, as defined by the V-web algorithm). ΔM is the mean density around a halo evaluated within a sphere of a radius of 5Rvir, where Rvir is the virial radius. ΔR is the density field Gaussian smoothed with R = 4 h-1 Mpc, evaluated at the centre of the halo. The main result of the paper is that the difference between haloes in different web elements stems from the difference in their mass functions, and does not depend on their adaptive-aperture ambient density. A dependence on the fixed-aperture ambient density is induced by the cross-correlation between the mass of a halo and its fixed-aperture ambient density.

  15. Stellar-to-halo mass relation of cluster galaxies

    Science.gov (United States)

    Niemiec, Anna; Jullo, Eric; Limousin, Marceau; Giocoli, Carlo; Erben, Thomas; Hildebrant, Hendrik; Kneib, Jean-Paul; Leauthaud, Alexie; Makler, Martin; Moraes, Bruno; Pereira, Maria E. S.; Shan, Huanyuan; Rozo, Eduardo; Rykoff, Eli; Van Waerbeke, Ludovic

    2017-10-01

    In the formation of galaxy groups and clusters, the dark matter haloes containing satellite galaxies are expected to be tidally stripped in gravitational interactions with the host. We use galaxy-galaxy weak lensing to measure the average mass of dark matter haloes of satellite galaxies as a function of projected distance to the centre of the host, since stripping is expected to be greater for satellites closer to the centre of the cluster. We further classify the satellites according to their stellar mass: Assuming that the stellar component of the galaxy is less disrupted by tidal stripping, stellar mass can be used as a proxy of the infall mass. We study the stellar-to-halo mass relation of satellites as a function of the cluster-centric distance to measure tidal stripping. We use the shear catalogues of the Dark Energy Survey (DES) science verification archive, the Canada-France-Hawaii Lensing Survey (CFHTLenS) and the CFHT Stripe 82 surveys, and we select satellites from the redMaPPer catalogue of clusters. For galaxies located in the outskirts of clusters, we find a stellar-to- halo mass relation in good agreement with the theoretical expectations from Moster et al. for central galaxies. In the centre of the cluster, we find that this relation is shifted to smaller halo mass for a given stellar mass. We interpret this finding as further evidence for tidal stripping of dark matter haloes in high-density environments.

  16. Nano-mechanics of HaloTag Tethers

    Science.gov (United States)

    Popa, Ionel; Berkovich, Ronen; Alegre-Cebollada, Jorge; Badilla, Carmen L.; Rivas-Pardo, Jaime Andres; Taniguchi, Yukinori; Kawakami, Masaru; Fernandez, Julio M.

    2013-01-01

    The active site of the Haloalkane Dehydrogenase (HaloTag) enzyme can be covalently attached to a chloroalkane ligand providing a mechanically strong tether, resistant to large pulling forces. Here we demonstrate the covalent tethering of protein L and I27 polyproteins between an AFM cantilever and a glass surface using HaloTag anchoring at one end, and thiol chemistry at the other end. Covalent tethering is unambiguously confirmed by the observation of full length polyprotein unfolding, combined with high detachment forces that range up to ~2000 pN. We use these covalently anchored polyproteins to study the remarkable mechanical properties of HaloTag proteins. We show that the force that triggers unfolding of the HaloTag protein exhibits a four-fold increase, from 131 pN to 491 pN, when the direction of the applied force is changed from the C-terminus to the N-terminus. Force-clamp experiments reveal that unfolding of the HaloTag protein is twice more sensitive to pulling force compared to protein L, and refolds at a slower rate. We show how these properties allow for the long-term observation of protein folding-unfolding cycles at high forces, without interference from the HaloTag tether. PMID:23909704

  17. What to expect from dynamical modelling of galactic haloes

    Science.gov (United States)

    Wang, Wenting; Han, Jiaxin; Cole, Shaun; Frenk, Carlos; Sawala, Till

    2017-09-01

    Many dynamical models of the Milky Way halo require assumptions that the distribution function of a tracer population should be independent of time (I.e. a steady-state distribution function) and that the underlying potential is spherical. We study the limitations of such modelling by applying a general dynamical model with minimal assumptions to a large sample of galactic haloes from cosmological N-body and hydrodynamical simulations. Using dark matter particles as dynamical tracers, we find that the systematic uncertainties in the measured mass and concentration parameters typically have an amplitude of 25-40 per cent. When stars are used as tracers, however, the systematic uncertainties can be as large as a factor of 2-3. The systematic uncertainties are not reduced by increasing the tracer sample size and vary stochastically from halo to halo. These systematic uncertainties are mostly driven by underestimated statistical noise caused by correlated phase-space structures that violate the steady-state assumption. The number of independent phase-space structures inferred from the uncertainty level sets a limiting sample size beyond which a further increase no longer significantly improves the accuracy of dynamical inferences. The systematic uncertainty level is determined by the halo merger history, the shape and environment of the halo. Our conclusions apply generally to any spherical steady-state model.

  18. Cold dark matter. 1: The formation of dark halos

    Science.gov (United States)

    Gelb, James M.; Bertschinger, Edmund

    1994-01-01

    We use numerical simulations of critically closed cold dark matter (CDM) models to study the effects of numerical resolution on observable quantities. We study simulations with up to 256(exp 3) particles using the particle-mesh (PM) method and with up to 144(exp 3) particles using the adaptive particle-particle-mesh (P3M) method. Comparisons of galaxy halo distributions are made among the various simulations. We also compare distributions with observations, and we explore methods for identifying halos, including a new algorithm that finds all particles within closed contours of the smoothed density field surrounding a peak. The simulated halos show more substructure than predicted by the Press-Schechter theory. We are able to rule out all omega = 1 CDM models for linear amplitude sigma(sub 8) greater than or approximately = 0.5 because the simulations produce too many massive halos compared with the observations. The simulations also produce too many low-mass halos. The distribution of halos characterized by their circular velocities for the P3M simulations is in reasonable agreement with the observations for 150 km/s less than or = V(sub circ) less than or = 350 km/s.

  19. RETRATAMENTO ENDODÔNTICO: ESTUDO COMPARATIVO ENTRE TÉCNICA MANUAL, ULTRA-SOM E CANAL FINDER ENDODONTIC RETREATMENT: COMPARATIVE STUDY BETWEEN MANUAL TECHNIQUE, ULTRASONIC SCALER, AND CANAL FINDER

    Directory of Open Access Journals (Sweden)

    Clovis Monteiro BRAMANTE

    1998-01-01

    Full Text Available Instrumentações manual, ultra-sônica e com Canal Finder foram utilizadas para retratamento de 30 dentes com canais obturados com guta-percha e óxido de zinco e eugenol. Avaliaram-se: 1. tempo gasto para a penetração inicial até o ápice; 2. tempo para completar a limpeza; 3. extrusão de material e 4. limpeza dos canais. O Canal Finder foi a técnica que propiciou melhor limpeza, seguida da manual e da ultra-sônica. A parede palatina do canal foi constantemente mais limpa do que a vestibular. Quanto à extrusão, a técnica de ultra-som foi a que propiciou mais extravasamento de material obturador.Endodontic retreatment of 30 teeth filled with guta percha and zinc oxide-eugenol was carried out using manual instrumentation, ultrasonic scaler, and the Canal Finder System. The following variables were evaluated: time spent to reach the apex; time spent to complete cleaning of the canal; apical extrusion of material; and cleanliness of the canals. Results showed the Canal Finder System as providing the highest level of cleanliness of the canal system; lingual walls were constantly cleaner than buccal walls; ultrasonic technique presented a greater degree of apical extrusion of filling material.

  20. Design of CMS Beam Halo Monitor system

    CERN Document Server

    AUTHOR|(CDS)2078842

    2015-01-01

    A fast and directional monitoring system for the CMS experiment is designed to provide an online, bunch-by-bunch measurement of beam background induced by beam halo interactions, separately for each beam. The background detection is based on Cherenkov radiation produced in synthetic fused silica read out by a fast, UV sensitive photomultiplier tube. Twenty detector units per end will be azimuthally distributed around the rotating shielding of CMS, covering ~408 cm2 at 20.6m from the interaction point, at a radius of ~180 cm. The directional and fast response of the system allows the discrimination of the background particles from the dominant flux in the cavern induced by pp collision debris, produced within the 25 ns bunch spacing. A robust multi-layered shielding will enclose each detector unit to protect the photomultiplier tube from the magnetic field and to eliminate the occupancy from low energy particles. The design of the front-end units is validated by experimental results. An overview of the new sy...

  1. The CMS Beam Halo Monitor electronics

    Science.gov (United States)

    Tosi, N.; Dabrowski, A. E.; Fabbri, F.; Grassi, T.; Hughes, E.; Mans, J.; Montanari, A.; Orfanelli, S.; Rusack, R.; Torromeo, G.; Stickland, D. P.; Stifter, K.

    2016-02-01

    The CMS Beam Halo Monitor has been successfully installed in the CMS cavern in LHC Long Shutdown 1 for measuring the machine induced background for LHC Run II. The system is based on 40 detector units composed of synthetic quartz Cherenkov radiators coupled to fast photomultiplier tubes (PMTs). The readout electronics chain uses many components developed for the Phase 1 upgrade to the CMS Hadronic Calorimeter electronics, with dedicated firmware and readout adapted to the beam monitoring requirements. The PMT signal is digitized by a charge integrating ASIC (QIE10), providing both the signal rise time, with few nanosecond resolution, and the charge integrated over one bunch crossing. The backend electronics uses microTCA technology and receives data via a high-speed 5 Gbps asynchronous link. It records histograms with sub-bunch crossing timing resolution and is read out via IPbus using the newly designed CMS data acquisition for non-event based data. The data is processed in real time and published to CMS and the LHC, providing online feedback on the beam quality. A dedicated calibration monitoring system has been designed to generate short triggered pulses of light to monitor the efficiency of the system. The electronics has been in operation since the first LHC beams of Run II and has served as the first demonstration of the new QIE10, Microsemi Igloo2 FPGA and high-speed 5 Gbps link with LHC data.

  2. Beam halo collimation in heavy ion synchrotrons

    Directory of Open Access Journals (Sweden)

    I. Strašík

    2015-08-01

    Full Text Available This paper presents a systematic study of the halo collimation of ion beams from proton up to uranium in synchrotrons. The projected Facility for Antiproton and Ion Research synchrotron SIS100 is used as a reference case. The concepts are separated into fully stripped (e.g., ^{238}U^{92+} and partially stripped (e.g., ^{238}U^{28+} ion collimation. An application of the two-stage betatron collimation system, well established for proton accelerators, is intended also for fully stripped ions. The two-stage system consists of a primary collimator (a scattering foil and secondary collimators (bulky absorbers. Interaction of the particles with the primary collimator (scattering, momentum losses, and nuclear interactions was simulated by using fluka. Particle-tracking simulations were performed by using mad-x. Finally, the dependence of the collimation efficiency on the primary ion species was determined. The influence of the collimation system adjustment, lattice imperfections, and beam parameters was estimated. The concept for the collimation of partially stripped ions employs a thin stripping foil in order to change their charge state. These ions are subsequently deflected towards a dump location using a beam optical element. The charge state distribution after the stripping foil was obtained from global. The ions were tracked by using mad–x.

  3. Performance of the CMS Beam Halo Monitor

    CERN Document Server

    CMS Collaboration

    2015-01-01

    The CMS Beam Halo Monitor has been successfully installed in the CMS cavern in LHC Long Shutdown 1 for measuring the machine induced background for LHC Run II. The system is based on 40 detector units composed of radiation hard synthetic quartz Cherenkov radiators coupled to fast photomultiplier tubes for a direction sensitive measurement. The readout electronics chain uses many components developed for the Phase 1 upgrade to the CMS Hadronic Calorimeter electronics, with dedicated firmware and readout adapted to the beam monitoring requirements. The PMT signal is digitized by a charge integrating ASIC (QIE10), providing both the signal rise time, with few ns resolution, and the charge integrated over one bunch crossing. The backend electronics uses microTCA technology and received data via a high-speed 5 Gbps asynchronous link. It records histograms with sub-bunch crossing timing resolution and is readout by IPbus using the newly designed CMS data acquisition for non-event based data. The data is processed i...

  4. The CMS Beam Halo Monitor Electronics

    CERN Document Server

    AUTHOR|(CDS)2080684; Fabbri, F.; Grassi, T.; Hughes, E.; Mans, J.; Montanari, A.; Orfanelli, S.; Rusack, R.; Torromeo, G.; Stickland, D.P.; Stifter, K.

    2016-01-01

    The CMS Beam Halo Monitor has been successfully installed in the CMS cavern in LHC Long Shutdown 1 for measuring the machine induced background for LHC Run II. The system is based on 40 detector units composed of synthetic quartz Cherenkov radiators coupled to fast photomultiplier tubes. The readout electronics chain uses many components developed for the Phase 1 upgrade to the CMS Hadronic Calorimeter electronics, with dedicated firmware and readout adapted to the beam monitoring requirements. The PMT signal is digitized by a charge integrating ASIC (QIE10), providing both the signal rise time, with few ns resolution, and the charge integrated over one bunch crossing. The backend electronics uses microTCA technology and receives data via a high-speed 5 Gbps asynchronous link. It records histograms with sub-bunch crossing timing resolution and is readout by IPbus using the newly designed CMS data acquisition for non-event based data. The data is processed in real time and published to CMS and the LHC, providi...

  5. HaloPROTACS: Use of Small Molecule PROTACs to Induce Degradation of HaloTag Fusion Proteins.

    Science.gov (United States)

    Buckley, Dennis L; Raina, Kanak; Darricarrere, Nicole; Hines, John; Gustafson, Jeffrey L; Smith, Ian E; Miah, Afjal H; Harling, John D; Crews, Craig M

    2015-08-21

    Small molecule-induced protein degradation is an attractive strategy for the development of chemical probes. One method for inducing targeted protein degradation involves the use of PROTACs, heterobifunctional molecules that can recruit specific E3 ligases to a desired protein of interest. PROTACs have been successfully used to degrade numerous proteins in cells, but the peptidic E3 ligase ligands used in previous PROTACs have hindered their development into more mature chemical probes or therapeutics. We report the design of a novel class of PROTACs that incorporate small molecule VHL ligands to successfully degrade HaloTag7 fusion proteins. These HaloPROTACs will inspire the development of future PROTACs with more drug-like properties. Additionally, these HaloPROTACs are useful chemical genetic tools, due to their ability to chemically knock down widely used HaloTag7 fusion proteins in a general fashion.

  6. Scalable Atomistic Simulation Algorithms for Materials Research

    Directory of Open Access Journals (Sweden)

    Aiichiro Nakano

    2002-01-01

    Full Text Available A suite of scalable atomistic simulation programs has been developed for materials research based on space-time multiresolution algorithms. Design and analysis of parallel algorithms are presented for molecular dynamics (MD simulations and quantum-mechanical (QM calculations based on the density functional theory. Performance tests have been carried out on 1,088-processor Cray T3E and 1,280-processor IBM SP3 computers. The linear-scaling algorithms have enabled 6.44-billion-atom MD and 111,000-atom QM calculations on 1,024 SP3 processors with parallel efficiency well over 90%. production-quality programs also feature wavelet-based computational-space decomposition for adaptive load balancing, spacefilling-curve-based adaptive data compression with user-defined error bound for scalable I/O, and octree-based fast visibility culling for immersive and interactive visualization of massive simulation data.

  7. Declarative and Scalable Selection for Map Visualizations

    DEFF Research Database (Denmark)

    Kefaloukos, Pimin Konstantin Balic

    supports the PostgreSQL dialect of SQL. The prototype implementation is a compiler that translates CVL into SQL and stored procedures. (c) TileHeat is a framework and basic algorithm for partial materialization of hot tile sets for scalable map distribution. The framework predicts future map workloads......, there are indications that the method is scalable for databases that contain millions of records, especially if the target language of the compiler is substituted by a cluster-ready variant of SQL. While several realistic use cases for maps have been implemented in CVL, additional non-geographic data visualization uses...... goal. The results for Tileheat show that the prediction method offers a substantial improvement over the current method used by the Danish Geodata Agency. Thus, a large amount of computations can potentially be saved by this public institution, who is responsible for the distribution of government...

  8. A Scalability Model for ECS's Data Server

    Science.gov (United States)

    Menasce, Daniel A.; Singhal, Mukesh

    1998-01-01

    This report presents in four chapters a model for the scalability analysis of the Data Server subsystem of the Earth Observing System Data and Information System (EOSDIS) Core System (ECS). The model analyzes if the planned architecture of the Data Server will support an increase in the workload with the possible upgrade and/or addition of processors, storage subsystems, and networks. The approaches in the report include a summary of the architecture of ECS's Data server as well as a high level description of the Ingest and Retrieval operations as they relate to ECS's Data Server. This description forms the basis for the development of the scalability model of the data server and the methodology used to solve it.

  9. Stencil Lithography for Scalable Micro- and Nanomanufacturing

    Directory of Open Access Journals (Sweden)

    Ke Du

    2017-04-01

    Full Text Available In this paper, we review the current development of stencil lithography for scalable micro- and nanomanufacturing as a resistless and reusable patterning technique. We first introduce the motivation and advantages of stencil lithography for large-area micro- and nanopatterning. Then we review the progress of using rigid membranes such as SiNx and Si as stencil masks as well as stacking layers. We also review the current use of flexible membranes including a compliant SiNx membrane with springs, polyimide film, polydimethylsiloxane (PDMS layer, and photoresist-based membranes as stencil lithography masks to address problems such as blurring and non-planar surface patterning. Moreover, we discuss the dynamic stencil lithography technique, which significantly improves the patterning throughput and speed by moving the stencil over the target substrate during deposition. Lastly, we discuss the future advancement of stencil lithography for a resistless, reusable, scalable, and programmable nanolithography method.

  10. Traitement des sigles dans le dictionnaire d’abrégements on line Acronym Finder

    Directory of Open Access Journals (Sweden)

    John Jairo Giraldo Ortiz

    2008-07-01

    Full Text Available La siglación, vista como un fenómeno de reducción léxica, se considera con frecuencia como unobstáculo para la comprensión de los textos, en particular por parte de los legos y los profesionalesen formación. Sin embargo, es un fenómeno cada vez más frecuente en todas las lenguas de especialidad(telecomunicaciones, informática, medicina, bioquímica, economía, etc.. Como resultado deesta proliferación, han aparecido en los últimos años diccionarios en línea para almacenar la grancantidad de abreviaciones tanto de la lengua general como de las lenguas de especialidad (e.g.: AcronymFinder, Acronym Server, Wiley InterScience, Acronyma, AbbreviationZ, Siglas, etc.. Todos estosrecursos utilizan a menudo la web como corpus para buscar las formas de reducción léxica. Antes hanexistido otras clases de recursos más populares que no debemos perder de vista; es decir, los diccionariosde siglas publicados en papel, por ejemplo, Alvar (1983, Martínez de Sousa (1984, Carton(1987, Pugh (1987, Bonk (2003, etc.Este artículo tiene por objetivo general determinar el tratamiento que se da a las abreviaciones en eldiccionario en línea Acronym Finder, puesto que se ha constatado una falta de información en estasunidades. Nuestro objetivo específico consiste en establecer un modelo de ficha para el almacenamientoy la descripción de los diferentes tipos de reducción léxica, es decir, las siglas, los acrónimoslas abreviaturas, etc.Este estudio se divide en tres partes, a saber: introducción, metodología y análisis y resultados. Enlo que respecta a la metodología, hemos descrito Acronym Finder. Posteriormente, hemos analizadosu microestructura. Se discuten los resultados, que muestran la información terminográficapresente o no en esta obra. Por último, se presentan las conclusiones de este trabajo y se proponeun modelo de ficha destinado a la recolección y almacenamiento de este tipo de unidades en formatoelectrónico.

  11. SPRNG Scalable Parallel Random Number Generator LIbrary

    Energy Technology Data Exchange (ETDEWEB)

    2010-03-16

    This revision corrects some errors in SPRNG 1. Users of newer SPRNG versions can obtain the corrected files and build their version with it. This version also improves the scalability of some of the application-based tests in the SPRNG test suite. It also includes an interface to a parallel Mersenne Twister, so that if users install the Mersenne Twister, then they can test this generator with the SPRNG test suite and also use some SPRNG features with that generator.

  12. Bitcoin-NG: A Scalable Blockchain Protocol

    OpenAIRE

    Eyal, Ittay; Gencer, Adem Efe; Sirer, Emin Gun; Renesse, Robbert,

    2015-01-01

    Cryptocurrencies, based on and led by Bitcoin, have shown promise as infrastructure for pseudonymous online payments, cheap remittance, trustless digital asset exchange, and smart contracts. However, Bitcoin-derived blockchain protocols have inherent scalability limits that trade-off between throughput and latency and withhold the realization of this potential. This paper presents Bitcoin-NG, a new blockchain protocol designed to scale. Based on Bitcoin's blockchain protocol, Bitcoin-NG is By...

  13. Stencil Lithography for Scalable Micro- and Nanomanufacturing

    OpenAIRE

    Ke Du; Junjun Ding; Yuyang Liu; Ishan Wathuthanthri; Chang-Hwan Choi

    2017-01-01

    In this paper, we review the current development of stencil lithography for scalable micro- and nanomanufacturing as a resistless and reusable patterning technique. We first introduce the motivation and advantages of stencil lithography for large-area micro- and nanopatterning. Then we review the progress of using rigid membranes such as SiNx and Si as stencil masks as well as stacking layers. We also review the current use of flexible membranes including a compliant SiNx membrane with spring...

  14. Performance of the VLT Planet Finder SPHERE. I. Photometry and astrometry precision with IRDIS and IFS in laboratory

    NARCIS (Netherlands)

    Zurlo, A.; Vigan, A.; Mesa, D.; Gratton, R.; Moutou, C.; Langlois, M.; Claudi, R.U.; Pueyo, L.; Boccaletti, A.; Baruffolo, A.; Beuzit, J.-L.; Costille, A.; Desidera, S.; Dohlen, K.; Feldt, M.; Fusco, T.; Henning, T.; Kasper, M.; Martinez, P.; Moeller-Nilsson, O.; Mouillet, D.; Pavlov, A.; Puget, P.; Sauvage, J.-F.; Turatto, M.; Udry, S.; Vakili, F.; Waters, R.; Wildi, R.F.

    2014-01-01

    Context. The new planet finder for the Very Large Telescope (VLT), the Spectro-Polarimetric High-contrast Exoplanet REsearch (SPHERE), just had its first light in Paranal. A dedicated instrument for the direct detection of planets, SPHERE, is composed of a polametric camera in visible light, the

  15. Scalable robotic biofabrication of tissue spheroids

    Energy Technology Data Exchange (ETDEWEB)

    Mehesz, A Nagy; Hajdu, Z; Visconti, R P; Markwald, R R; Mironov, V [Advanced Tissue Biofabrication Center, Department of Regenerative Medicine and Cell Biology, Medical University of South Carolina, Charleston, SC (United States); Brown, J [Department of Mechanical Engineering, Clemson University, Clemson, SC (United States); Beaver, W [York Technical College, Rock Hill, SC (United States); Da Silva, J V L, E-mail: mironovv@musc.edu [Renato Archer Information Technology Center-CTI, Campinas (Brazil)

    2011-06-15

    Development of methods for scalable biofabrication of uniformly sized tissue spheroids is essential for tissue spheroid-based bioprinting of large size tissue and organ constructs. The most recent scalable technique for tissue spheroid fabrication employs a micromolded recessed template prepared in a non-adhesive hydrogel, wherein the cells loaded into the template self-assemble into tissue spheroids due to gravitational force. In this study, we present an improved version of this technique. A new mold was designed to enable generation of 61 microrecessions in each well of a 96-well plate. The microrecessions were seeded with cells using an EpMotion 5070 automated pipetting machine. After 48 h of incubation, tissue spheroids formed at the bottom of each microrecession. To assess the quality of constructs generated using this technology, 600 tissue spheroids made by this method were compared with 600 spheroids generated by the conventional hanging drop method. These analyses showed that tissue spheroids fabricated by the micromolded method are more uniform in diameter. Thus, use of micromolded recessions in a non-adhesive hydrogel, combined with automated cell seeding, is a reliable method for scalable robotic fabrication of uniform-sized tissue spheroids.

  16. DISP: Optimizations towards Scalable MPI Startup

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Huansong [Florida State University, Tallahassee; Pophale, Swaroop S [ORNL; Gorentla Venkata, Manjunath [ORNL; Yu, Weikuan [Florida State University, Tallahassee

    2016-01-01

    Despite the popularity of MPI for high performance computing, the startup of MPI programs faces a scalability challenge as both the execution time and memory consumption increase drastically at scale. We have examined this problem using the collective modules of Cheetah and Tuned in Open MPI as representative implementations. Previous improvements for collectives have focused on algorithmic advances and hardware off-load. In this paper, we examine the startup cost of the collective module within a communicator and explore various techniques to improve its efficiency and scalability. Accordingly, we have developed a new scalable startup scheme with three internal techniques, namely Delayed Initialization, Module Sharing and Prediction-based Topology Setup (DISP). Our DISP scheme greatly benefits the collective initialization of the Cheetah module. At the same time, it helps boost the performance of non-collective initialization in the Tuned module. We evaluate the performance of our implementation on Titan supercomputer at ORNL with up to 4096 processes. The results show that our delayed initialization can speed up the startup of Tuned and Cheetah by an average of 32.0% and 29.2%, respectively, our module sharing can reduce the memory consumption of Tuned and Cheetah by up to 24.1% and 83.5%, respectively, and our prediction-based topology setup can speed up the startup of Cheetah by up to 80%.

  17. A scalable distributed RRT for motion planning

    KAUST Repository

    Jacobs, Sam Ade

    2013-05-01

    Rapidly-exploring Random Tree (RRT), like other sampling-based motion planning methods, has been very successful in solving motion planning problems. Even so, sampling-based planners cannot solve all problems of interest efficiently, so attention is increasingly turning to parallelizing them. However, one challenge in parallelizing RRT is the global computation and communication overhead of nearest neighbor search, a key operation in RRTs. This is a critical issue as it limits the scalability of previous algorithms. We present two parallel algorithms to address this problem. The first algorithm extends existing work by introducing a parameter that adjusts how much local computation is done before a global update. The second algorithm radially subdivides the configuration space into regions, constructs a portion of the tree in each region in parallel, and connects the subtrees,i removing cycles if they exist. By subdividing the space, we increase computation locality enabling a scalable result. We show that our approaches are scalable. We present results demonstrating almost linear scaling to hundreds of processors on a Linux cluster and a Cray XE6 machine. © 2013 IEEE.

  18. Numeric Analysis for Relationship-Aware Scalable Streaming Scheme

    Directory of Open Access Journals (Sweden)

    Heung Ki Lee

    2014-01-01

    Full Text Available Frequent packet loss of media data is a critical problem that degrades the quality of streaming services over mobile networks. Packet loss invalidates frames containing lost packets and other related frames at the same time. Indirect loss caused by losing packets decreases the quality of streaming. A scalable streaming service can decrease the amount of dropped multimedia resulting from a single packet loss. Content providers typically divide one large media stream into several layers through a scalable streaming service and then provide each scalable layer to the user depending on the mobile network. Also, a scalable streaming service makes it possible to decode partial multimedia data depending on the relationship between frames and layers. Therefore, a scalable streaming service provides a way to decrease the wasted multimedia data when one packet is lost. However, the hierarchical structure between frames and layers of scalable streams determines the service quality of the scalable streaming service. Even if whole packets of layers are transmitted successfully, they cannot be decoded as a result of the absence of reference frames and layers. Therefore, the complicated relationship between frames and layers in a scalable stream increases the volume of abandoned layers. For providing a high-quality scalable streaming service, we choose a proper relationship between scalable layers as well as the amount of transmitted multimedia data depending on the network situation. We prove that a simple scalable scheme outperforms a complicated scheme in an error-prone network. We suggest an adaptive set-top box (AdaptiveSTB to lower the dependency between scalable layers in a scalable stream. Also, we provide a numerical model to obtain the indirect loss of multimedia data and apply it to various multimedia streams. Our AdaptiveSTB enhances the quality of a scalable streaming service by removing indirect loss.

  19. An FPGA based track finder at L1 for CMS at the High Luminosity LHC

    CERN Document Server

    Amstutz, Christian; Balzer, Matthias Norbert; Brooke, James John; Calligaris, Luigi; Cieri, Davide; Clement, Emyr John; Hall, Geoffrey; Harbaum, Tanja Renate; Harder, Kristian; Hobson, Peter; Iles, Gregory Michiel; James, Thomas Owen; Manolopoulos, Konstantinos; Matsushita, Takashi; Morton, Alexander; Newbold, David; Paramesvaran, Sudarshan; Pesaresi, Mark Franco; Reid, Ivan; Rose, A. W; Sander, Oliver; Schuh, Thomas; Shepherd-Themistocleous, Claire; Shtipliyski, Antoni; Summers, Sioni Paris; Tapper, Alexander; Tomalin, Ian; Uchida, Kirika; Vichoudis, Paschalis; Weber, M

    2016-01-01

    A new CMS Tracker is under development for operation at the High Luminosity LHC from 2025. It includes an outer tracker based on PT-modules which will construct tracker stubs, built by correlating clusters in two closely spaced sensor layers for the rejection of low transverse momentum track hits, and transmit them off-detector at 40MHz. If tracker data is to contribute to maintaining the Level-1 trigger rate under increased luminosity, a crucial component of the upgrade will be the ability to identify tracks with transverse momentum above 3GeV/c by building tracks out of stubs. A concept for an FPGA-based track finder using a fully time-multiplexed spatially pipelined architecture is presented, where track candidates are identified using a projective binning algorithm. Results from a hardware demonstrator system, where a slice of the track trigger will be constructed to help gauge the performance and requirements for a full system, will be included.

  20. Application of the vector modulation method to the north finder capability gyroscope as a directional sensor

    Science.gov (United States)

    Celikel, Oguz

    2011-03-01

    This paper presents the application of the vector modulation method (VMM) to an open-loop interferometric fiber optic gyroscope, called the north finder capability gyroscope (NFCG), designed and assembled in TUBITAK UME (National Metrology Institute of Turkey). The method contains a secondary modulation/demodulation circuit with an AD630 chip, depending on the periodic variation of the orientation of the sensing coil sensitive surface vector with respect to geographic north at a laboratory latitude and collection of dc voltage at the secondary demodulation circuit output in the time domain. The resultant dc voltage proportional to the first-kind Bessel function based on Sagnac phase shift for the first order is obtained as a result of vector modulation together with the Earth's rotation. A new model function is developed and introduced to evaluate the angular errors of the NFCG with VMM in finding geographic north.

  1. Theory and modeling of the magnetic field measurement in LISA PathFinder

    CERN Document Server

    Diaz-Aguilo, M; Lobo, A

    2009-01-01

    The magnetic diagnostics subsystem of the LISA Technology Package (LTP) on board the LISA PathFinder (LPF) spacecraft includes a set of four tri-axial fluxgate magnetometers, intended to measure with high precision the magnetic field at their respective positions. However, their readouts do not provide a direct measurement of the magnetic field at the positions of the test masses, and hence an interpolation method must be designed and implemented to obtain the values of the magnetic field at these positions. However, such interpolation process faces serious difficulties. Indeed, the size of the interpolation region is excessive for a linear interpolation to be reliable while, on the other hand, the number of magnetometer channels does not provide sufficient data to go beyond the linear approximation. We describe an alternative method to address this issue, by means of neural network algorithms. The key point in this approach is the ability of neural networks to learn from suitable training data representing t...

  2. Milli-Hertz Gravitational Waves: LISA and LISA PathFinder

    Energy Technology Data Exchange (ETDEWEB)

    Araujo, H; Hollington, D; Wass, P [Blackett Laboratory, Imperial College London, Prince Consort Road, London SW7 2BW (United Kingdom); Canizares, P; Conchillo, A; Gesa, L; Lloro, I; Lobo, A; Mateos, I; Sopuerta, CF [Instituto de Ciencias del Espacio, CSIC, Campus UAB, Facultat de Ciencies, Torre C-5 Parell, 2a Planta, E-08193 Bellaterra (Cerdanyola del Valles), Barcelona (Spain); Chmeissani, M; Puigdengoles, C [Institut de Fisica d' Altes Energies (IFAE), Edifici C, Universitat Autonoma de Barcelona, 08193 Bellaterra, (Barcelona) (Spain); Diaz-Aguilo, M; Garcia-Berro, E; Gibert, F [Institut d' Estudis Espacials de Catalunya (IEEC), Edifici Nexus, Gran Capita 2-4, 08034 Barcelona (Spain); Grimani, C [Universita degli Studi di Urbino, and INFN Florence, Dipartimento DiSBeF, Via Santa Chiara 27, 61029 Urbino (Italy); Hajdas, W [Department of Particles and Matter, Paul Scherrer Institut, ODRA 120, 5232 Villigen (Switzerland); Nofrarias, M [Max-Planck-Institut fuer Gravitationsphysik (Albert-Einstein-Institut), Callinstrasse 38, D-30167 Hannover (Germany); Ramos-Castro, J [Departament d' Enginyeria Electronica, UPC, Campus Nord, Edif. C4, Jordi Girona 1-3, 08034 Barcelona (Spain); Sanjuan, J, E-mail: lobo@ieec.fcr.es [Department of Physics, University of Florida, NPB-22258 PO Box 118 440, Gainesville FL 32611-8440 (United States)

    2011-09-22

    Ground based GW detectors are limited at their lower frequency band (1-10 Hz) by settlement gravity gradients and seismic noise, and their sensitivity peaks at around 100 Hz. Sources in this band are mostly short duration signals, and their rates uncertain. Going down to milli-Hertz frequencies significantly increases the number and types of available sources. LISA was planned with the idea to explore a likely richer region of the GW spectrum, beyond that accessible to ground detectors; the latter are however expected to produce the first GW observations. In this paper I will present the main LISA concepts; in particular, emphasis will be placed on LISAPathFinder, the ESA precursor of LISA, in which our research group in Barcelona is heavily involved.

  3. Scalable and balanced dynamic hybrid data assimilation

    Science.gov (United States)

    Kauranne, Tuomo; Amour, Idrissa; Gunia, Martin; Kallio, Kari; Lepistö, Ahti; Koponen, Sampsa

    2017-04-01

    Scalability of complex weather forecasting suites is dependent on the technical tools available for implementing highly parallel computational kernels, but to an equally large extent also on the dependence patterns between various components of the suite, such as observation processing, data assimilation and the forecast model. Scalability is a particular challenge for 4D variational assimilation methods that necessarily couple the forecast model into the assimilation process and subject this combination to an inherently serial quasi-Newton minimization process. Ensemble based assimilation methods are naturally more parallel, but large models force ensemble sizes to be small and that results in poor assimilation accuracy, somewhat akin to shooting with a shotgun in a million-dimensional space. The Variational Ensemble Kalman Filter (VEnKF) is an ensemble method that can attain the accuracy of 4D variational data assimilation with a small ensemble size. It achieves this by processing a Gaussian approximation of the current error covariance distribution, instead of a set of ensemble members, analogously to the Extended Kalman Filter EKF. Ensemble members are re-sampled every time a new set of observations is processed from a new approximation of that Gaussian distribution which makes VEnKF a dynamic assimilation method. After this a smoothing step is applied that turns VEnKF into a dynamic Variational Ensemble Kalman Smoother VEnKS. In this smoothing step, the same process is iterated with frequent re-sampling of the ensemble but now using past iterations as surrogate observations until the end result is a smooth and balanced model trajectory. In principle, VEnKF could suffer from similar scalability issues as 4D-Var. However, this can be avoided by isolating the forecast model completely from the minimization process by implementing the latter as a wrapper code whose only link to the model is calling for many parallel and totally independent model runs, all of them

  4. ThioFinder: a web-based tool for the identification of thiopeptide gene clusters in DNA sequences.

    Directory of Open Access Journals (Sweden)

    Jing Li

    Full Text Available Thiopeptides are a growing class of sulfur-rich, highly modified heterocyclic peptides that are mainly active against Gram-positive bacteria including various drug-resistant pathogens. Recent studies also reveal that many thiopeptides inhibit the proliferation of human cancer cells, further expanding their application potentials for clinical use. Thiopeptide biosynthesis shares a common paradigm, featuring a ribosomally synthesized precursor peptide and conserved posttranslational modifications, to afford a characteristic core system, but differs in tailoring to furnish individual members. Identification of new thiopeptide gene clusters, by taking advantage of increasing information of DNA sequences from bacteria, may facilitate new thiopeptide discovery and enrichment of the unique biosynthetic elements to produce novel drug leads by applying the principle of combinatorial biosynthesis. In this study, we have developed a web-based tool ThioFinder to rapidly identify thiopeptide biosynthetic gene cluster from DNA sequence using a profile Hidden Markov Model approach. Fifty-four new putative thiopeptide biosynthetic gene clusters were found in the sequenced bacterial genomes of previously unknown producing microorganisms. ThioFinder is fully supported by an open-access database ThioBase, which contains the sufficient information of the 99 known thiopeptides regarding the chemical structure, biological activity, producing organism, and biosynthetic gene (cluster along with the associated genome if available. The ThioFinder website offers researchers a unique resource and great flexibility for sequence analysis of thiopeptide biosynthetic gene clusters. ThioFinder is freely available at http://db-mml.sjtu.edu.cn/ThioFinder/.

  5. The shape of the invisible halo: N-body simulations on parallel supercomputers

    Energy Technology Data Exchange (ETDEWEB)

    Warren, M.S.; Zurek, W.H. (Los Alamos National Lab., NM (USA)); Quinn, P.J. (Australian National Univ., Canberra (Australia). Mount Stromlo and Siding Spring Observatories); Salmon, J.K. (California Inst. of Tech., Pasadena, CA (USA))

    1990-01-01

    We study the shapes of halos and the relationship to their angular momentum content by means of N-body (N {approximately} 10{sup 6}) simulations. Results indicate that in relaxed halos with no apparent substructure: (i) the shape and orientation of the isodensity contours tends to persist throughout the virialised portion of the halo; (ii) most ({approx}70%) of the halos are prolate; (iii) the approximate direction of the angular momentum vector tends to persist throughout the halo; (iv) for spherical shells centered on the core of the halo the magnitude of the specific angular momentum is approximately proportional to their radius; (v) the shortest axis of the ellipsoid which approximates the shape of the halo tends to align with the rotation axis of the halo. This tendency is strongest in the fastest rotating halos. 13 refs., 4 figs.

  6. EasyGene – a prokaryotic gene finder that ranks ORFs by statistical significance

    Directory of Open Access Journals (Sweden)

    Larsen Thomas

    2003-06-01

    Full Text Available Abstract Background Contrary to other areas of sequence analysis, a measure of statistical significance of a putative gene has not been devised to help in discriminating real genes from the masses of random Open Reading Frames (ORFs in prokaryotic genomes. Therefore, many genomes have too many short ORFs annotated as genes. Results In this paper, we present a new automated gene-finding method, EasyGene, which estimates the statistical significance of a predicted gene. The gene finder is based on a hidden Markov model (HMM that is automatically estimated for a new genome. Using extensions of similarities in Swiss-Prot, a high quality training set of genes is automatically extracted from the genome and used to estimate the HMM. Putative genes are then scored with the HMM, and based on score and length of an ORF, the statistical significance is calculated. The measure of statistical significance for an ORF is the expected number of ORFs in one megabase of random sequence at the same significance level or better, where the random sequence has the same statistics as the genome in the sense of a third order Markov chain. Conclusions The result is a flexible gene finder whose overall performance matches or exceeds other methods. The entire pipeline of computer processing from the raw input of a genome or set of contigs to a list of putative genes with significance is automated, making it easy to apply EasyGene to newly sequenced organisms. EasyGene with pre-trained models can be accessed at http://www.cbs.dtu.dk/services/EasyGene.

  7. HaloTag as a reporter gene: positron emission tomography imaging with 64Cu-labeled second generation HaloTag ligands

    OpenAIRE

    Hong, Hao; Benink, Hélène A.; Uyeda, H. Tetsuo; Valdovinos, Hector F.; Zhang, Yin; Meisenheimer, Poncho; Barnhart, Todd E.; Fan, Frank; Cai, Weibo

    2013-01-01

    The goal of this study is to employ the HaloTag technology for positron emission tomography (PET), which involves two components: the HaloTag protein (a modified hydrolase which covalently binds to synthetic ligands) and HaloTag ligands (HTLs). 4T1 murine breast cancer cells were stably transfected to express HaloTag protein on the surface (termed as 4T1-HaloTag-ECS, ECS denotes extracellular surface). Two new HTLs were synthesized and termed NOTA-HTL2G-S and NOTA-HTL2G-L (2G indicates second...

  8. Halo formation and evolution: unifying physical properties with structure

    Science.gov (United States)

    Ernest, Alllan David; Collins, Matthew P.

    2015-08-01

    The assembly of matter in the universe proliferates a variety of structures with diverse properties. For example, massive halos of clusters of galaxies have temperatures often an order of magnitude or more higher than the individual galaxy halos within the cluster, or the temperatures of isolated galaxy halos. Giant spiral galaxies contain large quantities of both dark matter and hot gas while other structures like globular clusters appear to have little or no dark matter or gas. Still others, like the dwarf spheroidal galaxies have low gravity and little hot gas, but ironically contain some of the largest fractions of dark matter in the universe. Star forming rates (SFRs) also vary: compare for example the SFRs of giant elliptical galaxies, globular clusters, spiral and starburst galaxies. Furthermore there is evidence that the various structure types have existed over a large fraction of cosmic history. How can this array of variation in properties be reconciled with galaxy halo formation and evolution?We propose a model of halo formation [1] and evolution [2] that is consistent with both primordial nucleosynthesis (BBN) and the isotropies in the cosmic microwave background (CMB). The model uses two simple parameters, the total mass and size of a structure, to (1) explain why galaxies have the fractions of dark matter that they do (including why dwarf spheroidals are so dark matter dominated despite their weak gravity), (2) enable an understanding of the black hole-bulge/black hole-dark halo relations, (3) explain how fully formed massive galaxies can occur so early in cosmic history, (4) understand the connection between spiral and elliptical galaxies (5) unify the nature of globular clusters, dwarf spheroidal galaxies and bulges and (6) predict the temperatures of hot gas halos and understand how cool galaxy halos can remain stable in the hot environments of cluster-galaxy halos.[1] Ernest, A. D., 2012, in Prof. Ion Cotaescu (Ed) Advances in Quantum Theory, pp

  9. The Angular Momentum of Baryons and Dark Matter Halos Revisited

    Science.gov (United States)

    Kimm, Taysun; Devriendt, Julien; Slyz, Adrianne; Pichon, Christophe; Kassin, Susan A.; Dubois, Yohan

    2011-01-01

    Recent theoretical studies have shown that galaxies at high redshift are fed by cold, dense gas filaments, suggesting angular momentum transport by gas differs from that by dark matter. Revisiting this issue using high-resolution cosmological hydrodynamics simulations with adaptive-mesh refinement (AMR), we find that at the time of accretion, gas and dark matter do carry a similar amount of specific angular momentum, but that it is systematically higher than that of the dark matter halo as a whole. At high redshift, freshly accreted gas rapidly streams into the central region of the halo, directly depositing this large amount of angular momentum within a sphere of radius r = 0.1R(sub vir). In contrast, dark matter particles pass through the central region unscathed, and a fraction of them ends up populating the outer regions of the halo (r/R(sub vir) > 0.1), redistributing angular momentum in the process. As a result, large-scale motions of the cosmic web have to be considered as the origin of gas angular momentum rather than its virialised dark matter halo host. This generic result holds for halos of all masses at all redshifts, as radiative cooling ensures that a significant fraction of baryons remain trapped at the centre of the halos. Despite this injection of angular momentum enriched gas, we predict an amount for stellar discs which is in fair agreement with observations at z=0. This arises because the total specific angular momentum of the baryons (gas and stars) remains close to that of dark matter halos. Indeed, our simulations indicate that any differential loss of angular momentum amplitude between the two components is minor even though dark matter halos continuously lose between half and two-thirds of their specific angular momentum modulus as they evolve. In light of our results, a substantial revision of the standard theory of disc formation seems to be required. We propose a new scenario where gas efficiently carries the angular momentum generated

  10. HaloTag technology: a versatile platform for biomedical applications.

    Science.gov (United States)

    England, Christopher G; Luo, Haiming; Cai, Weibo

    2015-06-17

    Exploration of protein function and interaction is critical for discovering links among genomics, proteomics, and disease state; yet, the immense complexity of proteomics found in biological systems currently limits our investigational capacity. Although affinity and autofluorescent tags are widely employed for protein analysis, these methods have been met with limited success because they lack specificity and require multiple fusion tags and genetic constructs. As an alternative approach, the innovative HaloTag protein fusion platform allows protein function and interaction to be comprehensively analyzed using a single genetic construct with multiple capabilities. This is accomplished using a simplified process, in which a variable HaloTag ligand binds rapidly to the HaloTag protein (usually linked to the protein of interest) with high affinity and specificity. In this review, we examine all current applications of the HaloTag technology platform for biomedical applications, such as the study of protein isolation and purification, protein function, protein-protein and protein-DNA interactions, biological assays, in vitro cellular imaging, and in vivo molecular imaging. In addition, novel uses of the HaloTag platform are briefly discussed along with potential future applications.

  11. Deep brain transcranial magnetic stimulation using variable "Halo coil" system

    Science.gov (United States)

    Meng, Y.; Hadimani, R. L.; Crowther, L. J.; Xu, Z.; Qu, J.; Jiles, D. C.

    2015-05-01

    Transcranial Magnetic Stimulation has the potential to treat various neurological disorders non-invasively and safely. The "Halo coil" configuration can stimulate deeper regions of the brain with lower surface to deep-brain field ratio compared to other coil configurations. The existing "Halo coil" configuration is fixed and is limited in varying the site of stimulation in the brain. We have developed a new system based on the current "Halo coil" design along with a graphical user interface system that enables the larger coil to rotate along the transverse plane. The new system can also enable vertical movement of larger coil. Thus, this adjustable "Halo coil" configuration can stimulate different regions of the brain by adjusting the position and orientation of the larger coil on the head. We have calculated magnetic and electric fields inside a MRI-derived heterogeneous head model for various positions and orientations of the coil. We have also investigated the mechanical and thermal stability of the adjustable "Halo coil" configuration for various positions and orientations of the coil to ensure safe operation of the system.

  12. Halo-Independent Direct Detection Analyses Without Mass Assumptions

    CERN Document Server

    Anderson, Adam J.; Kahn, Yonatan; McCullough, Matthew

    2015-10-06

    Results from direct detection experiments are typically interpreted by employing an assumption about the dark matter velocity distribution, with results presented in the $m_\\chi-\\sigma_n$ plane. Recently methods which are independent of the DM halo velocity distribution have been developed which present results in the $v_{min}-\\tilde{g}$ plane, but these in turn require an assumption on the dark matter mass. Here we present an extension of these halo-independent methods for dark matter direct detection which does not require a fiducial choice of the dark matter mass. With a change of variables from $v_{min}$ to nuclear recoil momentum ($p_R$), the full halo-independent content of an experimental result for any dark matter mass can be condensed into a single plot as a function of a new halo integral variable, which we call $\\tilde{h}(p_R)$. The entire family of conventional halo-independent $\\tilde{g}(v_{min})$ plots for all DM masses are directly found from the single $\\tilde{h}(p_R)$ plot through a simple re...

  13. PointFinder: a novel web tool for WGS-based detection of antimicrobial resistance associated with chromosomal point mutations in bacterial pathogens

    DEFF Research Database (Denmark)

    Zankari, Ea; Allesøe, Rosa Lundbye; Joensen, Katrine Grimstrup

    2017-01-01

    enterica, Escherichia coli and Campylobacter jejuni. The web-server ResFinder-2.1 was used to identify acquired antimicrobial resistance genes and two methods, the novel PointFinder (using BLAST) and an in-house method (mapping of raw WGS reads), were used to identify chromosomal point mutations. Results...... or when mapping the reads. Conclusions PointFinder proved, with high concordance between phenotypic and predicted antimicrobial susceptibility, to be a user-friendly web tool for detection of chromosomal point mutations associated with antimicrobial resistance....

  14. Scalable resource management in high performance computers.

    Energy Technology Data Exchange (ETDEWEB)

    Frachtenberg, E. (Eitan); Petrini, F. (Fabrizio); Fernandez Peinador, J. (Juan); Coll, S. (Salvador)

    2002-01-01

    Clusters of workstations have emerged as an important platform for building cost-effective, scalable and highly-available computers. Although many hardware solutions are available today, the largest challenge in making large-scale clusters usable lies in the system software. In this paper we present STORM, a resource management tool designed to provide scalability, low overhead and the flexibility necessary to efficiently support and analyze a wide range of job scheduling algorithms. STORM achieves these feats by closely integrating the management daemons with the low-level features that are common in state-of-the-art high-performance system area networks. The architecture of STORM is based on three main technical innovations. First, a sizable part of the scheduler runs in the thread processor located on the network interface. Second, we use hardware collectives that are highly scalable both for implementing control heartbeats and to distribute the binary of a parallel job in near-constant time, irrespective of job and machine sizes. Third, we use an I/O bypass protocol that allows fast data movements from the file system to the communication buffers in the network interface and vice versa. The experimental results show that STORM can launch a job with a binary of 12MB on a 64 processor/32 node cluster in less than 0.25 sec on an empty network, in less than 0.45 sec when all the processors are busy computing other jobs, and in less than 0.65 sec when the network is flooded with a background traffic. This paper provides experimental and analytical evidence that these results scale to a much larger number of nodes. To the best of our knowledge, STORM is at least two orders of magnitude faster than existing production schedulers in launching jobs, performing resource management tasks and gang scheduling.

  15. Properties of dark matter haloes as a function of local environment density

    Science.gov (United States)

    Lee, Christoph T.; Primack, Joel R.; Behroozi, Peter; Rodríguez-Puebla, Aldo; Hellinger, Doug; Dekel, Avishai

    2017-04-01

    We study how properties of discrete dark matter haloes depend on halo environment, characterized by the mass density around the haloes on scales from 0.5 to 16 h-1 Mpc. We find that low-mass haloes (those less massive than the characteristic mass MC of haloes collapsing at a given epoch) in high-density environments have lower accretion rates, lower spins, higher concentrations and rounder shapes than haloes in median density environments. Haloes in median- and low-density environments have similar accretion rates and concentrations, but haloes in low-density environments have lower spins and are more elongated. Haloes of a given mass in high-density regions accrete material earlier than haloes of the same mass in lower density regions. All but the most massive haloes in high-density regions are losing mass (i.e. being stripped) at low redshifts, which causes artificially lowered NFW scale radii and increased concentrations. Tidal effects are also responsible for the decreasing spins of low-mass haloes in high-density regions at low redshifts z spins because they lack nearby haloes whose tidal fields can spin them up. We also show that the simulation density distribution is well fit by an extreme value distribution, and that the density distribution becomes broader with cosmic time.

  16. Combined Scalable Video Coding Method for Wireless Transmission

    Directory of Open Access Journals (Sweden)

    Achmad Affandi

    2011-08-01

    Full Text Available Mobile video streaming is one of multimedia services that has developed very rapidly. Recently, bandwidth utilization for wireless transmission is the main problem in the field of multimedia communications. In this research, we offer a combination of scalable methods as the most attractive solution to this problem. Scalable method for wireless communication should adapt to input video sequence. Standard ITU (International Telecommunication Union - Joint Scalable Video Model (JSVM is employed to produce combined scalable video coding (CSVC method that match the required quality of video streaming services for wireless transmission. The investigation in this paper shows that combined scalable technique outperforms the non-scalable one, in using bit rate capacity at certain layer.

  17. Towards a Scalable, Biomimetic, Antibacterial Coating

    Science.gov (United States)

    Dickson, Mary Nora

    Corneal afflictions are the second leading cause of blindness worldwide. When a corneal transplant is unavailable or contraindicated, an artificial cornea device is the only chance to save sight. Bacterial or fungal biofilm build up on artificial cornea devices can lead to serious complications including the need for systemic antibiotic treatment and even explantation. As a result, much emphasis has been placed on anti-adhesion chemical coatings and antibiotic leeching coatings. These methods are not long-lasting, and microorganisms can eventually circumvent these measures. Thus, I have developed a surface topographical antimicrobial coating. Various surface structures including rough surfaces, superhydrophobic surfaces, and the natural surfaces of insects' wings and sharks' skin are promising anti-biofilm candidates, however none meet the criteria necessary for implementation on the surface of an artificial cornea device. In this thesis I: 1) developed scalable fabrication protocols for a library of biomimetic nanostructure polymer surfaces 2) assessed the potential these for poly(methyl methacrylate) nanopillars to kill or prevent formation of biofilm by E. coli bacteria and species of Pseudomonas and Staphylococcus bacteria and improved upon a proposed mechanism for the rupture of Gram-negative bacterial cell walls 3) developed a scalable, commercially viable method for producing antibacterial nanopillars on a curved, PMMA artificial cornea device and 4) developed scalable fabrication protocols for implantation of antibacterial nanopatterned surfaces on the surfaces of thermoplastic polyurethane materials, commonly used in catheter tubings. This project constitutes a first step towards fabrication of the first entirely PMMA artificial cornea device. The major finding of this work is that by precisely controlling the topography of a polymer surface at the nano-scale, we can kill adherent bacteria and prevent biofilm formation of certain pathogenic bacteria

  18. Programming Scala Scalability = Functional Programming + Objects

    CERN Document Server

    Wampler, Dean

    2009-01-01

    Learn how to be more productive with Scala, a new multi-paradigm language for the Java Virtual Machine (JVM) that integrates features of both object-oriented and functional programming. With this book, you'll discover why Scala is ideal for highly scalable, component-based applications that support concurrency and distribution. Programming Scala clearly explains the advantages of Scala as a JVM language. You'll learn how to leverage the wealth of Java class libraries to meet the practical needs of enterprise and Internet projects more easily. Packed with code examples, this book provides us

  19. Scalable and Anonymous Group Communication with MTor

    Directory of Open Access Journals (Sweden)

    Lin Dong

    2016-04-01

    Full Text Available This paper presents MTor, a low-latency anonymous group communication system. We construct MTor as an extension to Tor, allowing the construction of multi-source multicast trees on top of the existing Tor infrastructure. MTor does not depend on an external service to broker the group communication, and avoids central points of failure and trust. MTor’s substantial bandwidth savings and graceful scalability enable new classes of anonymous applications that are currently too bandwidth-intensive to be viable through traditional unicast Tor communication-e.g., group file transfer, collaborative editing, streaming video, and real-time audio conferencing.

  20. Scalable conditional induction variables (CIV) analysis

    DEFF Research Database (Denmark)

    Oancea, Cosmin Eugen; Rauchwerger, Lawrence

    2015-01-01

    representation. Our technique requires no modifications of our dependence tests, which is agnostic to the original shape of the subscripts, and is more powerful than previously reported dependence tests that rely on the pairwise disambiguation of read-write references. We have implemented the CIV analysis in our...... parallelizing compiler and evaluated its impact on five Fortran benchmarks. We have found that that there are many important loops using CIV subscripts and that our analysis can lead to their scalable parallelization. This in turn has led to the parallelization of the benchmark programs they appear in....

  1. Tip-Based Nanofabrication for Scalable Manufacturing

    Directory of Open Access Journals (Sweden)

    Huan Hu

    2017-03-01

    Full Text Available Tip-based nanofabrication (TBN is a family of emerging nanofabrication techniques that use a nanometer scale tip to fabricate nanostructures. In this review, we first introduce the history of the TBN and the technology development. We then briefly review various TBN techniques that use different physical or chemical mechanisms to fabricate features and discuss some of the state-of-the-art techniques. Subsequently, we focus on those TBN methods that have demonstrated potential to scale up the manufacturing throughput. Finally, we discuss several research directions that are essential for making TBN a scalable nano-manufacturing technology.

  2. Subdural abscess associated with halo-pin traction.

    Science.gov (United States)

    Garfin, S R; Botte, M J; Triggs, K J; Nickel, V L

    1988-10-01

    Osteomyelitis and intracranial abscess are among the most serious complications that have been reported in association with the use of the halo device. The cases of five patients who had formation of an intracranial abscess related to the use of a halo cervical immobilizer are described. All of the infections resolved after drainage of the abscess, débridement, and parenteral administration of antibiotics. Meticulous care of the pin sites is essential to avoid this serious complication. Additionally, since all of the infections were associated with prolonged halo-skeletal traction, this technique should be used with caution and with an awareness of the possible increased risks of pin-site infection and of formation of a subdural abscess.

  3. Direct photoassociation of halo molecules in ultracold 86 Sr

    Science.gov (United States)

    Aman, J. A.; Hill, Joshua; Killian, T. C.

    2017-04-01

    We investigate the creation of 1S0 +1S0 halo molecules in strontium 86 through direct photoassociation in an optical dipole trap. We drive two photon Raman transitions near-resonance with a molecular level of the 1S0 +3P1 interatomic potential as the intermediate state. This provides large Frank-Condon factors and allows us to observe resonances for the creation of halo molecules through higher order Raman processes. The halo molecule is bound by EB 85 kHz at low excitation-laser intensity, but experiments show large AC Stark shifts of the molecular binding energy. These conditions suggest that STIRAP should be very effective for improving molecular conversion efficiency. Further experiments in a 3D lattice will explore molecular lifetimes and collision rates. Travel support provided by Shell Corporation.

  4. Axionic dark matter signatures in various halo models

    Energy Technology Data Exchange (ETDEWEB)

    Vergados, J.D., E-mail: vergados@uoi.gr [Center for Axion and Precision Physics Research, Institute for Basic Science (IBS), Daejeon 34141 (Korea, Republic of); Department of Physics, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141 (Korea, Republic of); ARC Centre of Excellence in Particle Physics at the Terascale and Centre for the Subatomic Structure of Matter (CSSM), University of Adelaide, Adelaide SA 5005 (Australia); Semertzidis, Y.K. [Center for Axion and Precision Physics Research, Institute for Basic Science (IBS), Daejeon 34141 (Korea, Republic of); Department of Physics, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141 (Korea, Republic of)

    2017-02-15

    In the present work we study possible signatures in the Axion Dark Matter searches. We focus on the dependence of the expected width in resonant cavities for various popular halo models, leading to standard velocity distributions, e.g. Maxwell–Boltzmann, as well as phase-mixed and non-virialized axionic dark matter (flows, caustic rings). We study, in particular, the time dependence of the resonance width (modulation) arising from such models. We find that the difference between the maximum (in June) and the minimum (in December) can vary by about 10% in the case of standard halos. In the case of mixed phase halos the variation is a bit bigger and for caustic rings the maximum is expected to occur a bit later. Experimentally such a modulation is observable with present technology.

  5. Particle ejection during mergers of dark matter halos

    Energy Technology Data Exchange (ETDEWEB)

    Carucci, Isabella P.; Sparre, Martin; Hansen, Steen H. [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, Copenhagen, 2100 Denmark (Denmark); Joyce, Michael, E-mail: carucci@dark-cosmology.dk, E-mail: sparre@dark-cosmology.dk, E-mail: hansen@dark-cosmology.dk, E-mail: joyce@lpnhe.in2p3.fr [Laboratoire de Physique Nucléaire et Hautes Énergies, Université Pierre et Marie Curie - Paris 6, CNRS IN2P3 UMR 7585, 4 Place Jussieu, Paris Cedex 05, 75752 France (France)

    2014-06-01

    Dark matter halos are built from accretion and merging. During merging some of the dark matter particles may be ejected with velocities higher than the escape velocity. We use both N-body simulations and single-particle smooth-field simulations to demonstrate that rapid changes to the mean field potential are responsible for such ejection, and in particular that dynamical friction plays no significant role in it. Studying a range of minor mergers, we find that typically between 5–15% of the particles from the smaller of the two merging structures are ejected. We also find that the ejected particles originate essentially from the small halo, and more specifically are particles in the small halo which pass later through the region in which the merging occurs.

  6. Simulation Studies of the Helium and Lead Observatory (HALO)

    Science.gov (United States)

    Sanford, Nikki; Scholberg, Kate

    2012-10-01

    Simulation studies for were conducted for the Helium and Lead Observatory (HALO), the supernova neutrino detector at SNOLAB, Sudbury, Ontario. HALO consists of 79 tons of lead, with 128 ^3He counters which detect the scattered lead neutrons resulting from incoming neutrinos. Improvements were made to the Geant4 Monte Carlo simulation's geometry by the addition of water boxes and plastic baseboards, which serve to reflect scattered neutrons back towards counters, and shield against outside neutrons and gammas. Several box designs were created, and the resulting event detection efficiencies and labeling of 1n and 2n events were studied. It was found that these additions cause a 2% efficiency increase, a slight improvement of correctly labeled events, and are a significant improvement to the HALO simulation.

  7. Reactions of Proton Halo Nuclei in a Relativistic Optical Potential

    CERN Document Server

    Rashdan, M

    2003-01-01

    The reaction cross section, sigma sub R; of the proton halo nuclei sup 1 sup 7 Ne and sup 1 sup 2 N on Si is calculated using an optical potential derived from the solution of the Dirac-Brueckner-Bethe-Goldstone equation, starting from the one-boson-exchange potential of Bonn. The nuclear densities are generated from self-consistent Hartree-Fock calculations using the recent Skyrme interaction SKRA. It is found that the enhancement in the reaction cross section found experimentally for the sup 1 sup 7 Ne + Si system in comparison to sup 1 sup 5 O + Si, where sup 1 sup 5 O has been considered as a core of sup 1 sup 7 Ne, is mainly due to the proton halo structure of sup 1 sup 7 Ne which increases the interaction, in the surface and tail regions. Glauber model calculations did not produce this enhancement in sigma sub R for proton halo nuclei

  8. Scalable Engineering of Quantum Optical Information Processing Architectures (SEQUOIA)

    Science.gov (United States)

    2016-12-13

    scalable architecture for LOQC and cluster state quantum computing (Ballistic or non-ballistic) - With parametric nonlinearities (Kerr, chi-2...Scalable Engineering of Quantum Optical Information-Processing Architectures (SEQUOIA) 5a. CONTRACT NUMBER W31-P4Q-15-C-0045 5b. GRANT NUMBER 5c...Technologies 13 December 2016 “Scalable Engineering of Quantum Optical Information-Processing Architectures (SEQUOIA)” Final R&D Status Report

  9. Three-body halo nuclei in an effective theory framework

    Energy Technology Data Exchange (ETDEWEB)

    Canham, David L.

    2009-05-20

    The universal properties and structure of halo nuclei composed of two neutrons (2n) and a core are investigated within an effective quantum mechanics framework. We construct an effective interaction potential that exploits the separation of scales in halo nuclei and treat the nucleus as an effective three-body system, which to leading order is described by the large S-wave scattering lengths in the underlying two-body subsystems. The uncertainty from higher orders in the expansion is quantified through theoretical error bands. First, we investigate the possibility to observe excited Efimov states in 2n halo nuclei. Based on the experimental data, {sup 20}C is the only halo nucleus candidate to possibly have an Efimov excited state, with an energy less than 7 keV below the scattering threshold. Second, we study the structure of {sup 20}C and other 2n halo nuclei. In particular, we calculate their matter density form factors, radii, and two-neutron opening angles. We then make a systematic improvement upon these calculations by extending the effective potential to the next-to-leading order. To this order, we require an additional two-body parameter, which we tune to the effective range of the interaction. In addition to range corrections to the 2n halo nuclei results, we show corrections to the Efimov effect in the three-boson system. Furthermore, we explore universality in the linear range corrections to the Efimov spectrum. Finally, we study the scattering of D{sup 0} and D{sup *0} mesons and their antiparticles off the X(3872) in an effective field theory for short-range interactions. We present results for the S-wave scattering amplitude, total interaction cross section and S-wave scattering length. (orig.)

  10. Capacity of straylight and disk halo size to diagnose cataract.

    Science.gov (United States)

    Palomo-Álvarez, Catalina; Puell, María C

    2015-10-01

    To examine the capacity of straylight and disk halo size to diagnose cataract. Faculty of Optics and Optometry, Universidad Complutense de Madrid, Spain. Prospective study. Straylight, disk halo radius, and high-contrast corrected distance visual acuity (CDVA) measurements were compared between patients with age-related cataract and age-matched normal-sighted control subjects by calculating the area under the curve (AUC) receiver operating characteristic. Measurements were made in 53 eyes of 53 patients with a mean age of 67.94 years ± 7.11 (SD) and 31 eyes of 31 controls with a mean age 66.06 ± 5.43 years. Significantly worse (P cataract group than in the control group (1.17 ± 0.11 log[s], 2.10 ± 0.16 log arcmin, and 0.08 ± 0.08 logMAR). Significant differences in AUCs were observed for disk halo radius (0.89 ± 0.04) versus straylight (0.77 ± 0.05) (P = .03) and disk halo radius versus CDVA (0.72 ± 0.05) (P = .001). The comparison of disk halo radius versus the discriminant function with input from CDVA and straylight (0.80 ± 0.05) was at the limit of significance only (0.091 ± 0.05, P = .051). Although all 3 variables discriminated well between normal eyes and eyes with cataract, the disk halo radius showed the best diagnostic capacity. Neither author has a financial or proprietary interest in any material or method mentioned. Copyright © 2015 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  11. The orbital eccentricity distribution of solar-neighbourhood halo stars

    Science.gov (United States)

    Hattori, K.; Yoshii, Y.

    2011-12-01

    We present theoretical calculations for the differential distribution of stellar orbital eccentricity for a sample of solar-neighbourhood halo stars. Two types of static, spherical gravitational potentials are adopted to define the eccentricity e for given energy E and angular momentum L, such as an isochrone potential and a Navarro-Frenk-White potential that can serve as two extreme ends covering in between any realistic potential of the Milky Way halo. The solar-neighbourhood eccentricity distribution ΔN(e) is then formulated, based on a static distribution function of the form f(E, L) in which the velocity anisotropy parameter β monotonically increases in the radial direction away from the galaxy centre, such that β is below unity (near-isotropic velocity dispersion) in the central region and asymptotically approaches ˜1 (radially anisotropic velocity dispersion) in the far distant region of the halo. We find that ΔN(e) sensitively depends upon the radial profile of β, and this sensitivity is used to constrain such a profile in comparison with some observational properties of ΔNobs(e) recently reported by Carollo et al. In particular, the linear e-distribution and the fraction of higher e stars for their sample of solar-neighbourhood inner-halo stars rule out a constant profile of β, contrary to the opposite claim by Bond et al. Our constraint of β≲ 0.5 at the galaxy centre indicates that the violent relaxation that has acted on the inner halo is effective within a scale radius of ˜10 kpc from the galaxy centre. We argue that our result would help to understand the formation and evolution of the Milky Way halo.

  12. The Halo Boundary of Galaxy Clusters in the SDSS

    Energy Technology Data Exchange (ETDEWEB)

    Baxter, Eric; Jain, Bhuvnesh; Sheth, Ravi K. [Center for Particle Cosmology, Department of Physics, University of Pennsylvania, Philadelphia, PA 19104 (United States); Chang, Chihway; Kravtsov, Andrey [Kavli Institute for Cosmological Physics, The University of Chicago, Chicago, IL 60637 (United States); Adhikari, Susmita; Dalal, Neal [Department of Astronomy, University of Illinois at Urbana-Champaign, Champaign, IL 61801 (United States); More, Surhud [Kavli Institute for the Physics and Mathematics of the Universe (WPI), Tokyo Institutes for Advanced Study, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa-shi, Chiba, 277-8583 (Japan); Rozo, Eduardo [Department of Physics, University of Arizona, Tucson, AZ 85721 (United States); Rykoff, Eli, E-mail: ebax@sas.upenn.edu [Kavli Institute for Particle Astrophysics and Cosmology, P.O. Box 2450, Stanford University, Stanford, CA 94305 (United States)

    2017-05-20

    Analytical models and simulations predict a rapid decline in the halo density profile associated with the transition from the “infalling” regime outside the halo to the “collapsed” regime within the halo. Using data from SDSS, we explore evidence for such a feature in the density profiles of galaxy clusters using several different approaches. We first estimate the steepening of the outer galaxy density profile around clusters, finding evidence for truncation of the halo profile. Next, we measure the galaxy density profile around clusters using two sets of galaxies selected on color. We find evidence of an abrupt change in galaxy colors that coincides with the location of the steepening of the density profile. Since galaxies that have completed orbits within the cluster are more likely to be quenched of star formation and thus appear redder, this abrupt change in galaxy color can be associated with the transition from single-stream to multi-stream regimes. We also use a standard model comparison approach to measure evidence for a “splashback”-like feature, but find that this approach is very sensitive to modeling assumptions. Finally, we perform measurements using an independent cluster catalog to test for potential systematic errors associated with cluster selection. We identify several avenues for future work: improved understanding of the small-scale galaxy profile, lensing measurements, identification of proxies for the halo accretion rate, and other tests. With upcoming data from the DES, KiDS, and HSC surveys, we can expect significant improvements in the study of halo boundaries.

  13. Signatures of compact halos of sterile-neutrino dark matter

    Science.gov (United States)

    Kühnel, Florian; Ohlsson, Tommy

    2017-11-01

    We investigate compact halos of sterile-neutrino dark matter and examine observable signatures with respect to neutrino and photon emission. Primarily, we consider two cases: primordial black-hole halos and ultracompact minihalos. In both cases, we find that there exists a broad range of possible parameter choices such that detection in the near future with x-ray and gamma-ray telescopes might be well possible. In fact, for energies above 10 TeV, the neutrino telescope IceCube would be a splendid detection machine for such macroscopic dark-matter candidates.

  14. The FUSE Survey of 0 VI in the Galactic Halo

    Science.gov (United States)

    Sonneborn, George; Savage, B. D.; Wakker, B. P.; Sembach, K. R.; Jenkins, E. B.; Moos, H. W.; Shull, J. M.

    2003-01-01

    This paper summarizes the results of the Far-Ultraviolet Spectroscopic Explorer (FUSE) program to study 0 VI in the Milky Way halo. Spectra of 100 extragalactic objects and two distant halo stars are analyzed to obtain measures of O VI absorption along paths through the Milky Way thick disk/halo. Strong O VI absorption over the velocity range from -100 to 100 km/s reveals a widespread but highly irregular distribution of O VI, implying the existence of substantial amounts of hot gas with T approx. 3 x 10(exp 5) K in the Milky Way thick disk/halo. The overall distribution of O VI is not well described by a symmetrical plane-parallel layer of patchy O VI absorption. The simplest departure from such a model that provides a reasonable fit to the observations is a plane-parallel patchy absorbing layer with an average O VI mid-plane density of n(sub 0)(O VI) = 1.7 x 10(exp -2)/cu cm, a scale height of approx. 2.3 kpc, and a approx. 0.25 dex excess of O VI in the northern Galactic polar region. The distribution of O VI over the sky is poorly correlated with other tracers of gas in the halo, including low and intermediate velocity H I, Ha emission from the warm ionized gas at approx. l0(exp 4) K, and hot X-ray emitting gas at approx. l0(exp 6) K . The O VI has an average velocity dispersion, b approx. 60 km/s and standard deviation of 15 km/s. Thermal broadening alone cannot explain the large observed profile widths. A combination of models involving the radiative cooling of hot fountain gas, the cooling of supernova bubbles in the halo, and the turbulent mixing of warm and hot halo gases is required to explain the presence of O VI and other highly ionized atoms found in the halo. The preferential venting of hot gas from local bubbles and superbubbles into the northern Galactic polar region may explain the enhancement of O VI in the North.

  15. Two distinct halo populations in the solar neighborhood. IV

    DEFF Research Database (Denmark)

    Nissen, P. E.; Schuster, W. J.

    2012-01-01

    We investigate if there is a difference in the lithium abundances of stars belonging to two halo populations of F and G main-sequence stars previously found to differ in [alpha/Fe] for the metallicity range -1.4 ...-resolution spectra using MARCS model atmospheres. Furthermore, masses of the stars are determined from the logTeff - logg diagram by interpolating between Yonsei-Yale evolutionary tracks. There is no significant systematic difference in the lithium abundances of high- and low-alpha halo stars. For the large majority...

  16. Dynamical Constraints On The Galaxy-Halo Connection

    Science.gov (United States)

    Desmond, Harry

    2017-07-01

    Dark matter halos comprise the bulk of the universe's mass, yet must be probed by the luminous galaxies that form within them. A key goal of modern astrophysics, therefore, is to robustly relate the visible and dark mass, which to first order means relating the properties of galaxies and halos. This may be expected not only to improve our knowledge of galaxy formation, but also to enable high-precision cosmological tests using galaxies and hence maximise the utility of future galaxy surveys. As halos are inaccessible to observations - as galaxies are to N-body simulations - this relation requires an additional modelling step.The aim of this thesis is to develop and evaluate models of the galaxy-halo connection using observations of galaxy dynamics. In particular, I build empirical models based on the technique of halo abundance matching for five key dynamical scaling relations of galaxies - the Tully-Fisher, Faber-Jackson, mass-size and mass discrepancy-acceleration relations, and Fundamental Plane - which relate their baryon distributions and rotation or velocity dispersion profiles. I then develop a statistical scheme based on approximate Bayesian computation to compare the predicted and measured values of a number of summary statistics describing the relations' important features. This not only provides quantitative constraints on the free parameters of the models, but also allows absolute goodness-of-fit measures to be formulated. I find some features to be naturally accounted for by an abundance matching approach and others to impose new constraints on the galaxy-halo connection; the remainder are challenging to account for and may imply galaxy-halo correlations beyond the scope of basic abundance matching.Besides providing concrete statistical tests of specific galaxy formation theories, these results will be of use for guiding the inputs of empirical and semi-analytic galaxy formation models, which require galaxy-halo correlations to be imposed by hand. As

  17. Big data integration: scalability and sustainability

    KAUST Repository

    Zhang, Zhang

    2016-01-26

    Integration of various types of omics data is critically indispensable for addressing most important and complex biological questions. In the era of big data, however, data integration becomes increasingly tedious, time-consuming and expensive, posing a significant obstacle to fully exploit the wealth of big biological data. Here we propose a scalable and sustainable architecture that integrates big omics data through community-contributed modules. Community modules are contributed and maintained by different committed groups and each module corresponds to a specific data type, deals with data collection, processing and visualization, and delivers data on-demand via web services. Based on this community-based architecture, we build Information Commons for Rice (IC4R; http://ic4r.org), a rice knowledgebase that integrates a variety of rice omics data from multiple community modules, including genome-wide expression profiles derived entirely from RNA-Seq data, resequencing-based genomic variations obtained from re-sequencing data of thousands of rice varieties, plant homologous genes covering multiple diverse plant species, post-translational modifications, rice-related literatures, and community annotations. Taken together, such architecture achieves integration of different types of data from multiple community-contributed modules and accordingly features scalable, sustainable and collaborative integration of big data as well as low costs for database update and maintenance, thus helpful for building IC4R into a comprehensive knowledgebase covering all aspects of rice data and beneficial for both basic and translational researches.

  18. Using MPI to Implement Scalable Libraries

    Science.gov (United States)

    Lusk, Ewing

    MPI is an instantiation of a general-purpose programming model, and high-performance implementations of the MPI standard have provided scalability for a wide range of applications. Ease of use was not an explicit goal of the MPI design process, which emphasized completeness, portability, and performance. Thus it is not surprising that MPI is occasionally criticized for being inconvenient to use and thus a drag on software developer productivity. One approach to the productivity issue is to use MPI to implement simpler programming models. Such models may limit the range of parallel algorithms that can be expressed, yet provide sufficient generality to benefit a significant number of applications, even from different domains.We illustrate this concept with the ADLB (Asynchronous, Dynamic Load-Balancing) library, which can be used to express manager/worker algorithms in such a way that their execution is scalable, even on the largestmachines. ADLB makes sophisticated use ofMPI functionality while providing an extremely simple API for the application programmer.We will describe it in the context of solving Sudoku puzzles and a nuclear physics Monte Carlo application currently running on tens of thousands of processors.

  19. Scalable fast multipole accelerated vortex methods

    KAUST Repository

    Hu, Qi

    2014-05-01

    The fast multipole method (FMM) is often used to accelerate the calculation of particle interactions in particle-based methods to simulate incompressible flows. To evaluate the most time-consuming kernels - the Biot-Savart equation and stretching term of the vorticity equation, we mathematically reformulated it so that only two Laplace scalar potentials are used instead of six. This automatically ensuring divergence-free far-field computation. Based on this formulation, we developed a new FMM-based vortex method on heterogeneous architectures, which distributed the work between multicore CPUs and GPUs to best utilize the hardware resources and achieve excellent scalability. The algorithm uses new data structures which can dynamically manage inter-node communication and load balance efficiently, with only a small parallel construction overhead. This algorithm can scale to large-sized clusters showing both strong and weak scalability. Careful error and timing trade-off analysis are also performed for the cutoff functions induced by the vortex particle method. Our implementation can perform one time step of the velocity+stretching calculation for one billion particles on 32 nodes in 55.9 seconds, which yields 49.12 Tflop/s.

  20. Using the scalable nonlinear equations solvers package

    Energy Technology Data Exchange (ETDEWEB)

    Gropp, W.D.; McInnes, L.C.; Smith, B.F.

    1995-02-01

    SNES (Scalable Nonlinear Equations Solvers) is a software package for the numerical solution of large-scale systems of nonlinear equations on both uniprocessors and parallel architectures. SNES also contains a component for the solution of unconstrained minimization problems, called SUMS (Scalable Unconstrained Minimization Solvers). Newton-like methods, which are known for their efficiency and robustness, constitute the core of the package. As part of the multilevel PETSc library, SNES incorporates many features and options from other parts of PETSc. In keeping with the spirit of the PETSc library, the nonlinear solution routines are data-structure-neutral, making them flexible and easily extensible. This users guide contains a detailed description of uniprocessor usage of SNES, with some added comments regarding multiprocessor usage. At this time the parallel version is undergoing refinement and extension, as we work toward a common interface for the uniprocessor and parallel cases. Thus, forthcoming versions of the software will contain additional features, and changes to parallel interface may result at any time. The new parallel version will employ the MPI (Message Passing Interface) standard for interprocessor communication. Since most of these details will be hidden, users will need to perform only minimal message-passing programming.

  1. Towards Scalable Graph Computation on Mobile Devices

    Science.gov (United States)

    Chen, Yiqi; Lin, Zhiyuan; Pienta, Robert; Kahng, Minsuk; Chau, Duen Horng

    2015-01-01

    Mobile devices have become increasingly central to our everyday activities, due to their portability, multi-touch capabilities, and ever-improving computational power. Such attractive features have spurred research interest in leveraging mobile devices for computation. We explore a novel approach that aims to use a single mobile device to perform scalable graph computation on large graphs that do not fit in the device's limited main memory, opening up the possibility of performing on-device analysis of large datasets, without relying on the cloud. Based on the familiar memory mapping capability provided by today's mobile operating systems, our approach to scale up computation is powerful and intentionally kept simple to maximize its applicability across the iOS and Android platforms. Our experiments demonstrate that an iPad mini can perform fast computation on large real graphs with as many as 272 million edges (Google+ social graph), at a speed that is only a few times slower than a 13″ Macbook Pro. Through creating a real world iOS app with this technique, we demonstrate the strong potential application for scalable graph computation on a single mobile device using our approach. PMID:25859564

  2. Scalability Optimization of Seamless Positioning Service

    Directory of Open Access Journals (Sweden)

    Juraj Machaj

    2016-01-01

    Full Text Available Recently positioning services are getting more attention not only within research community but also from service providers. From the service providers point of view positioning service that will be able to work seamlessly in all environments, for example, indoor, dense urban, and rural, has a huge potential to open new markets. However, such system does not only need to provide accurate position estimates but have to be scalable and resistant to fake positioning requests. In the previous works we have proposed a modular system, which is able to provide seamless positioning in various environments. The system automatically selects optimal positioning module based on available radio signals. The system currently consists of three positioning modules—GPS, GSM based positioning, and Wi-Fi based positioning. In this paper we will propose algorithm which will reduce time needed for position estimation and thus allow higher scalability of the modular system and thus allow providing positioning services to higher amount of users. Such improvement is extremely important, for real world application where large number of users will require position estimates, since positioning error is affected by response time of the positioning server.

  3. An Open Infrastructure for Scalable, Reconfigurable Analysis

    Energy Technology Data Exchange (ETDEWEB)

    de Supinski, B R; Fowler, R; Gamblin, T; Mueller, F; Ratn, P; Schulz, M

    2008-05-15

    Petascale systems will have hundreds of thousands of processor cores so their applications must be massively parallel. Effective use of petascale systems will require efficient interprocess communication through memory hierarchies and complex network topologies. Tools to collect and analyze detailed data about this communication would facilitate its optimization. However, several factors complicate tool design. First, large-scale runs on petascale systems will be a precious commodity, so scalable tools must have almost no overhead. Second, the volume of performance data from petascale runs could easily overwhelm hand analysis and, thus, tools must collect only data that is relevant to diagnosing performance problems. Analysis must be done in-situ, when available processing power is proportional to the data. We describe a tool framework that overcomes these complications. Our approach allows application developers to combine existing techniques for measurement, analysis, and data aggregation to develop application-specific tools quickly. Dynamic configuration enables application developers to select exactly the measurements needed and generic components support scalable aggregation and analysis of this data with little additional effort.

  4. Toward a Combined SAGE II-HALOE Aerosol Climatology: An Evaluation of HALOE Version 19 Stratospheric Aerosol Extinction Coefficient Observations

    Science.gov (United States)

    Thomason, L. W.

    2012-01-01

    Herein, the Halogen Occultation Experiment (HALOE) aerosol extinction coefficient data is evaluated in the low aerosol loading period after 1996 as the first necessary step in a process that will eventually allow the production of a combined HALOE/SAGE II (Stratospheric Aerosol and Gas Experiment) aerosol climatology of derived aerosol products including surface area density. Based on these analyses, it is demonstrated that HALOE's 3.46 microns is of good quality above 19 km and suitable for scientific applications above that altitude. However, it is increasingly suspect at lower altitudes and should not be used below 17 km under any circumstances after 1996. The 3.40 microns is biased by about 10% throughout the lower stratosphere due to the failure to clear NO2 but otherwise appears to be a high quality product down to 15 km. The 2.45 and 5.26 micron aerosol extinction coefficient measurements are clearly biased and should not be used for scientific applications after the most intense parts of the Pinatubo period. Many of the issues in the aerosol data appear to be related to either the failure to clear some interfering gas species or doing so poorly. For instance, it is clear that the 3.40micronaerosol extinction coefficient measurements can be improved through the inclusion of an NO2 correction and could, in fact, end up as the highest quality overall HALOE aerosol extinction coefficient measurement. It also appears that the 2.45 and 5.26 micron channels may be improved by updating the Upper Atmosphere Pilot Database which is used as a resource for the removal of gas species otherwise not available from direct HALOE measurements. Finally, a simple model to demonstrate the promise of mixed visible/infrared aerosol extinction coefficient ensembles for the retrieval of bulk aerosol properties demonstrates that a combined HALOE/SAGE II aerosol climatology is feasible and may represent a substantial improvement over independently derived data sets.

  5. HaloTag: a novel reporter gene for positron emission tomography

    OpenAIRE

    Hong, Hao; Benink, Hélène A.; Zhang, Yin; Yang, Yunan; Uyeda, H. Tetsuo; Engle, Jonathan W.; Severin, Gregory W.; McDougall, Mark G; Barnhart, Todd E.; Klaubert, Dieter H.; Nickles, Robert J; Fan, Frank; Cai, Weibo

    2011-01-01

    Among the many molecular imaging techniques, reporter gene imaging has been a dynamic area of research. The HaloTag protein is a modified haloalkane dehalogenase which was designed to covalently bind to synthetic ligands (i.e. the HaloTag ligands [HTL]). Covalent bond formation between the HaloTag protein and the chloroal-kane within the HTL occurs rapidly under physiological conditions, which is highly specific and essentially irreversible. Over the years, HaloTag technology has been investi...

  6. Resolution of vitiligo following excision of halo congenital melanocytic nevus: a rare case report.

    Science.gov (United States)

    Wang, Kai; Wang, Zhi; Huang, Weiqing

    2016-05-01

    Halo congenital melanocytic nevus (CMN) associated with vitiligo is rare, especially with regard to CMN excision. Only two reports of excision of halo CMN following repigmentation of vitiligo are found in the literature. We present a case of a girl with halo CMN and periorbital vitiligo. The halo CMN was excised and followed by spontaneous improvement of vitiligo. The result suggests excision of the inciting lesion may be a promising way to control vitiligo. © 2015 Wiley Periodicals, Inc.

  7. AnimalFinder: A semi-automated system for animal detection in time-lapse camera trap images

    Science.gov (United States)

    Price Tack, Jennifer L.; West, Brian S.; McGowan, Conor P.; Ditchkoff, Stephen S.; Reeves, Stanley J.; Keever, Allison; Grand, James B.

    2017-01-01

    Although the use of camera traps in wildlife management is well established, technologies to automate image processing have been much slower in development, despite their potential to drastically reduce personnel time and cost required to review photos. We developed AnimalFinder in MATLAB® to identify animal presence in time-lapse camera trap images by comparing individual photos to all images contained within the subset of images (i.e. photos from the same survey and site), with some manual processing required to remove false positives and collect other relevant data (species, sex, etc.). We tested AnimalFinder on a set of camera trap images and compared the presence/absence results with manual-only review with white-tailed deer (Odocoileus virginianus), wild pigs (Sus scrofa), and raccoons (Procyon lotor). We compared abundance estimates, model rankings, and coefficient estimates of detection and abundance for white-tailed deer using N-mixture models. AnimalFinder performance varied depending on a threshold value that affects program sensitivity to frequently occurring pixels in a series of images. Higher threshold values led to fewer false negatives (missed deer images) but increased manual processing time, but even at the highest threshold value, the program reduced the images requiring manual review by ~40% and correctly identified >90% of deer, raccoon, and wild pig images. Estimates of white-tailed deer were similar between AnimalFinder and the manual-only method (~1–2 deer difference, depending on the model), as were model rankings and coefficient estimates. Our results show that the program significantly reduced data processing time and may increase efficiency of camera trapping surveys.

  8. Pla(y)cefully – når børn finder sted gennemt transformationer af institutionelle konstruktioner

    DEFF Research Database (Denmark)

    Nørgård, Rikke Toft; Toft, Herdis

    2014-01-01

    , designere, kunstnere, pædagoger og forældre understøtte, at børn finder sted som mennesker i verden? Et svar kunne være, at vi, snarere end at indplacere børn i ’satte’ institutionelle kontekster, lader børn ’sætte’ deres eget sted, fx ved at lade dem ’pla(y)cefully’ transformere, hvad et gulv i en...

  9. De bepaling van halo-azijnzuren, chloriet en chloraat in drinkwater

    NARCIS (Netherlands)

    Peters RJB; van de Meer-Arp KKM; Versteegh JFM

    1990-01-01

    A method was developed to determine halo-acetic acids with a detection limit of 0.1 mug/L. Halo-acetic acids were determined in samples drinking water derived from surface- and bankfiltrated water however, not in drinking water derived from groundwater. Halo-acetic acids were found in chlorinated

  10. Describing one-and two-neutron halos in effective field theory

    Indian Academy of Sciences (India)

    2014-11-01

    Nov 1, 2014 ... Click here to view fulltext PDF ... In this paper, the recent work our group has undertaken on effective field theory (EFT) analyses of experimental data pertaining to one- and two-neutron halo nuclei is discussed. The cases of 19C and 8Li (one-neutron halos) and 22C (two-neutron halo) are considered.

  11. PTM MarkerFinder, a software tool to detect and validate spectra from peptides carrying post-translational modifications.

    Science.gov (United States)

    Nanni, Paolo; Panse, Christian; Gehrig, Peter; Mueller, Susanne; Grossmann, Jonas; Schlapbach, Ralph

    2013-08-01

    Mass spectrometry (MS) analysis of peptides carrying post-translational modifications is challenging due to the instability of some modifications during MS analysis. However, glycopeptides as well as acetylated, methylated and other modified peptides release specific fragment ions during CID (collision-induced dissociation) and HCD (higher energy collisional dissociation) fragmentation. These fragment ions can be used to validate the presence of the PTM on the peptide. Here, we present PTM MarkerFinder, a software tool that takes advantage of such marker ions. PTM MarkerFinder screens the MS/MS spectra in the output of a database search (i.e., Mascot) for marker ions specific for selected PTMs. Moreover, it reports and annotates the HCD and the corresponding electron transfer dissociation (ETD) spectrum (when present), and summarizes information on the type, number, and ratios of marker ions found in the data set. In the present work, a sample containing enriched N-acetylhexosamine (HexNAc) glycopeptides from yeast has been analyzed by liquid chromatography-mass spectrometry on an LTQ Orbitrap Velos using both HCD and ETD fragmentation techniques. The identification result (Mascot .dat file) was submitted as input to PTM MarkerFinder and screened for HexNAc oxonium ions. The software output has been used for high-throughput validation of the identification results. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. BioJava-ModFinder: identification of protein modifications in 3D structures from the Protein Data Bank.

    Science.gov (United States)

    Gao, Jianjiong; Prlic, Andreas; Bi, Chunxiao; Bluhm, Wolfgang F; Dimitropoulos, Dimitris; Xu, Dong; Bourne, Philip E; Rose, Peter W

    2017-07-01

    We developed a new software tool, BioJava-ModFinder, for identifying protein modifications observed in 3D structures archived in the Protein Data Bank (PDB). Information on more than 400 types of protein modifications were collected and curated from annotations in PDB, RESID, and PSI-MOD. We divided these modifications into three categories: modified residues, attachment modifications, and cross-links. We have developed a systematic method to identify these modifications in 3D protein structures. We have integrated this package with the RCSB PDB web application and added protein modification annotations to the sequence diagram and structure display. By scanning all 3D structures in the PDB using BioJava-ModFinder, we identified more than 30 000 structures with protein modifications, which can be searched, browsed, and visualized on the RCSB PDB website. BioJava-ModFinder is available as open source (LGPL license) at ( https://github.com/biojava/biojava/tree/master/biojava-modfinder ). The RCSB PDB can be accessed at http://www.rcsb.org . pwrose@ucsd.edu.

  13. LC-IMS-MS Feature Finder: detecting multidimensional liquid chromatography, ion mobility and mass spectrometry features in complex datasets.

    Science.gov (United States)

    Crowell, Kevin L; Slysz, Gordon W; Baker, Erin S; LaMarche, Brian L; Monroe, Matthew E; Ibrahim, Yehia M; Payne, Samuel H; Anderson, Gordon A; Smith, Richard D

    2013-11-01

    The addition of ion mobility spectrometry to liquid chromatography-mass spectrometry experiments requires new, or updated, software tools to facilitate data processing. We introduce a command line software application LC-IMS-MS Feature Finder that searches for molecular ion signatures in multidimensional liquid chromatography-ion mobility spectrometry-mass spectrometry (LC-IMS-MS) data by clustering deisotoped peaks with similar monoisotopic mass, charge state, LC elution time and ion mobility drift time values. The software application includes an algorithm for detecting and quantifying co-eluting chemical species, including species that exist in multiple conformations that may have been separated in the IMS dimension. LC-IMS-MS Feature Finder is available as a command-line tool for download at http://omics.pnl.gov/software/LC-IMS-MS_Feature_Finder.php. The Microsoft.NET Framework 4.0 is required to run the software. All other dependencies are included with the software package. Usage of this software is limited to non-profit research to use (see README). rds@pnnl.gov. Supplementary data are available at Bioinformatics online.

  14. Prospects for detecting supersymmetric dark matter in the Galactic halo

    NARCIS (Netherlands)

    Springel, V.; White, S. D. M.; Frenk, C. S.; Navarro, J. F.; Jenkins, A.; Vogelsberger, M.; Wang, J.; Ludlow, A.; Helmi, A.

    2008-01-01

    Dark matter is the dominant form of matter in the Universe, but its nature is unknown. It is plausibly an elementary particle, perhaps the lightest supersymmetric partner of known particle species(1). In this case, annihilation of dark matter in the halo of the Milky Way should produce gamma-rays at

  15. The Galactic Halo in Mixed Dark Matter Cosmologies

    NARCIS (Netherlands)

    Anderhalden, D.; Diemand, J.; Bertone, G.; Macciò, A.V.; Schneider, A.

    2012-01-01

    A possible solution to the small scale problems of the cold dark matter (CDM) scenario is that the dark matter consists of two components, a cold and a warm one. We perform a set of high resolution simulations of the Milky Way halo varying the mass of the WDM particle (mWDM) and the cosmic dark

  16. The prolate shape of the galactic dark-matter halo

    NARCIS (Netherlands)

    Helmi, A; Spooner, NJC; Kudryavtsev,

    2005-01-01

    Knowledge of the distribution of dark-matter in our Galaxy plays a crucial role in the interpretation of dark-matter detection experiments. I will argue here that probably the best way of constraining the properties of the dark-matter halo is through astrophysical observations. These provide

  17. Redshift space bias and beta from the halo model

    OpenAIRE

    Seljak, Uros

    2000-01-01

    We analyze scale dependence of redshift space bias $b$ and $\\beta \\equiv \\Omega_m^{0.6}/b$ in the context of the halo model. We show that linear bias is a good approximation only on large scales, for $k

  18. Lithium abundances in high- and low-alpha halo stars

    DEFF Research Database (Denmark)

    Nissen, P. E.; Schuster, W. J.

    2012-01-01

    A previous study of F and G main-sequence stars in the solar neighborhood has revealed the existence of two distinct halo populations with a clear separation in [alpha /Fe] for the metallicity range -1.4 < [Fe/H] < -0.7. The kinematics of the stars and models of galaxy formation suggest that the ...

  19. On the shape of the Galactic dark matter halo

    NARCIS (Netherlands)

    Helmi, A

    2004-01-01

    The confined nature of the debris from the Sagittarius dwarf to a narrow trail on the sky has recently prompted the suggestion that the dark matter halo of our Galaxy should be nearly spherical (Ibata et al. 2001; Majewski et al. 2003). This would seem to be in strong contrast with predictions from

  20. Jet interactions with the hot halos of clusters and galaxies

    NARCIS (Netherlands)

    McNamara, B.R.; Bîrzan, L.; Rafferty, D.A.; Nulsen, P.E.J.; Carilli, C.; Wise, M.W.

    2008-01-01

    X-ray observations of cavities and shock fronts produced by jets streaming through hot halos have significantly advanced our understanding of the energetics and dynamics of extragalactic radio sources. Radio sources at the centers of clusters have dynamical ages between ten and several hundred

  1. A halo model for cosmological neutral hydrogen : abundances and clustering

    Science.gov (United States)

    Padmanabhan, Hamsa; Refregier, Alexandre; Amara, Adam

    2017-08-01

    We extend the results of previous analyses towards constraining the abundance and clustering of post-reionization (z ∼ 0-5) neutral hydrogen (H i) systems using a halo model framework. We work with a comprehensive H I data set including the small-scale clustering, column density and mass function of H I galaxies at low redshifts, intensity mapping measurements at intermediate redshifts and the ultraviolet/optical observations of Damped Lyman Alpha (DLA) systems at higher redshifts. We use a Markov Chain Monte Carlo (MCMC) approach to constrain the parameters of the best-fitting models, both for the H i-halo mass (HIHM) relation and the H I radial density profile. We find that a radial exponential profile results in a good fit to the low-redshift H I observations, including the clustering and the column density distribution. The form of the profile is also found to match the high-redshift DLA observations, when used in combination with a three-parameter HIHM relation and a redshift evolution in the H I concentration. The halo model predictions are in good agreement with the observed H I surface density profiles of low-redshift galaxies, and the general trends in the impact parameter and covering fraction observations of high-redshift DLAs. We provide convenient tables summarizing the best-fitting halo model predictions.

  2. The Disk Mass Project: breaking the disk-halo degeneracy

    NARCIS (Netherlands)

    Verheijen, Marc A. W.; Bershady, Matthew A.; Swaters, Rob A.; Andersen, David R.; Westfall, Kyle B.; DE JONG, R. S.

    2007-01-01

    Little is known about the content and distribution of dark matter in spiral galaxies. To break the degeneracy in galaxy rotation curve decompositions, which allows a wide range of dark matter halo density profiles, an independent measure of the mass surface density of stellar disks is needed. Here,

  3. Halo-like structures studied by atomic force microscopy

    DEFF Research Database (Denmark)

    Sørensen, Alexis Hammer; Kyhle, Anders; Hansen, L. Theil

    1997-01-01

    Nanometer-sized clusters of copper have been produced in a hollow cathode sputtering source and deposited on SiOx. Halo-like structures consisting of micrometer sized protrusions in the solicon oxide surface surrounded by thin rings of smaller particles are observed. The area in between seems...

  4. The influence of halo evolution on galaxy structure

    Science.gov (United States)

    White, Simon

    2015-03-01

    If Einstein-Newton gravity holds on galactic and larger scales, then current observations demonstrate that the stars and interstellar gas of a typical bright galaxy account for only a few percent of its total nonlinear mass. Dark matter makes up the rest and cannot be faint stars or any other baryonic form because it was already present and decoupled from the radiation plasma at z = 1000, long before any nonlinear object formed. The weak gravito-sonic waves so precisely measured by CMB observations are detected again at z = 4 as order unity fluctuations in intergalactic matter. These subsequently collapse to form today's galaxy/halo systems, whose mean mass profiles can be accurately determined through gravitational lensing. High-resolution simulations link the observed dark matter structures seen at all these epochs, demonstrating that they are consistent and providing detailed predictions for all aspects of halo structure and growth. Requiring consistency with the abundance and clustering of real galaxies strongly constrains the galaxy-halo relation, both today and at high redshift. This results in detailed predictions for galaxy assembly histories and for the gravitational arena in which galaxies live. Dark halos are not expected to be passive or symmetric but to have a rich and continually evolving structure which will drive evolution in the central galaxy over its full life, exciting warps, spiral patterns and tidal arms, thickening disks, producing rings, bars and bulges. Their growth is closely related to the provision of new gas for galaxy building.

  5. Large-scale assembly bias of dark matter halos

    Science.gov (United States)

    Lazeyras, Titouan; Musso, Marcello; Schmidt, Fabian

    2017-03-01

    We present precise measurements of the assembly bias of dark matter halos, i.e. the dependence of halo bias on other properties than the mass, using curved "separate universe" N-body simulations which effectively incorporate an infinite-wavelength matter overdensity into the background density. This method measures the LIMD (local-in-matter-density) bias parameters bn in the large-scale limit. We focus on the dependence of the first two Eulerian biases bE1 and bE2 on four halo properties: the concentration, spin, mass accretion rate, and ellipticity. We quantitatively compare our results with previous works in which assembly bias was measured on fairly small scales. Despite this difference, our findings are in good agreement with previous results. We also look at the joint dependence of bias on two halo properties in addition to the mass. Finally, using the excursion set peaks model, we attempt to shed new insights on how assembly bias arises in this analytical model.

  6. Halo formation from mismatched beam-beam interactions

    Energy Technology Data Exchange (ETDEWEB)

    Qiang, Ji

    2003-05-23

    In this paper, we report on the halo formation and emittance growth driven by a parametric resonance during mismatched beam-beam collisions. In the regime of the weak-strong beam-beam interaction, if two beams have the same machine tunes, on-axis head-on collisions between a mismatched strong beam and a weak beam will not cause the formation of halo. However, if the two beams collide with an initial offset, the beam-beam force from the mismatched strong beam can cause halo formation and emittance growth in the weak beam. Meanwhile, if two beams have different machine tunes, for opposite charged colliding beams, when the machine tune of the weak beam is smaller than that of strong beam, there is emittance growth in the weak beam. When the machine tune of the weak beam is larger than that of the strong beam, there is little emittance growth. In the regime of strong-strong beam-beam interaction, halo is formed in both beams even when the two beams collide head-on on the axis with equal machine tunes. This puts a strong requirement for a good beam match during the injection to colliders in order to avoid the emittance growth.

  7. Haloes and clustering in light, neutron-rich nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Orr, N.A

    2001-10-01

    Clustering is a relatively widespread phenomenon which takes on many guises across the nuclear landscape. Selected topics concerning the study of halo systems and clustering in light, neutron-rich nuclei are discussed here through illustrative examples taken from the Be isotopic chain. (author)

  8. Planetary Nebulae as kinematic and dynamical tracers of galaxy halos

    NARCIS (Netherlands)

    Coccato, Lodovico; Napolitano, Nicola; Arnaboldi, Magda; Cortesi, Arianna; Romanowsky, Aaron; Gerhard, Ortwin; Merrifield, Michael; Kuijken, Konrad; Freeman, Ken; Douglas, Nigel

    2015-01-01

    The kinematics and dynamical properties of galaxy halos are difficult to measure, given the faint stellar surface brightness that characterizes those regions. Gas-rich systems such as spiral galaxies can be probed using the radio emission of their gas component. Early type galaxies contain less gas,

  9. Uncovering the hidden iceberg structure of the Galactic halo

    Science.gov (United States)

    Moss, Vanessa A.; Di Teodoro, Enrico M.; McClure-Griffiths, Naomi M.; Lockman, Felix; Pisano, D. J.; Price, Daniel; Rees, Glen

    2018-01-01

    How the Milky Way gets its gas and keeps its measured star formation rate going are both long-standing mysteries in Galactic studies, with important implications for galaxy evolution across the Universe. I will present our recent discovery of two populations of neutral hydrogen (HI) in the halo of the Milky Way: 1) a narrow line-width dense population typical of the majority of bright high velocity cloud (HVC) components, and 2) a fainter, broad line-width diffuse population that aligns well with the population found in very sensitive pointings such as in Lockman et al. (2002). From our existing data, we concluded that the diffuse population likely outweighs the dense HI by a factor of 3. This discovery of diffuse HI, which appears to be prevalent throughout the halo, takes us closer to solving the Galactic mystery of accretion and reveals a gaseous neutral halo hidden from the view of most large-scale surveys. We are currently carrying out deep Parkes observations to investigate these results further, in order to truly uncover the nature of the diffuse HI and determine whether our 3:1 ratio (based on the limited existing data) is consistent with what is seen when Parkes and the 140 ft Green Bank telescope are employed at comparable sensitivity. With these data, through a combination of both known and new sightline measurements, we aim to reveal the structure of the Galactic halo in more detail than ever before.

  10. The reversed halo sign: update and differential diagnosis

    Science.gov (United States)

    Godoy, M C B; Viswanathan, C; Marchiori, E; Truong, M T; Benveniste, M F; Rossi, S; Marom, E M

    2012-01-01

    The reversed halo sign is characterised by a central ground-glass opacity surrounded by denser air–space consolidation in the shape of a crescent or a ring. It was first described on high-resolution CT as being specific for cryptogenic organising pneumonia. Since then, the reversed halo sign has been reported in association with a wide range of pulmonary diseases, including invasive pulmonary fungal infections, paracoccidioidomycosis, pneumocystis pneumonia, tuberculosis, community-acquired pneumonia, lymphomatoid granulomatosis, Wegener granulomatosis, lipoid pneumonia and sarcoidosis. It is also seen in pulmonary neoplasms and infarction, and following radiation therapy and radiofrequency ablation of pulmonary malignancies. In this article, we present the spectrum of neoplastic and non-neoplastic diseases that may show the reversed halo sign and offer helpful clues for assisting in the differential diagnosis. By integrating the patient's clinical history with the presence of the reversed halo sign and other accompanying radiological findings, the radiologist should be able to narrow the differential diagnosis substantially, and may be able to provide a presumptive final diagnosis, which may obviate the need for biopsy in selected cases, especially in the immunosuppressed population. PMID:22553298

  11. Alpha alpha scattering in halo effective field theory

    NARCIS (Netherlands)

    Higa, R.; Hammer, H. -W.; van Kolck, U.

    2008-01-01

    We study the two-alpha-particle (alpha alpha) system in an Effective Field Theory (EFT) for halo-like systems. We propose a power Counting that incorporates the subtle interplay of strong and electromagnetic forces leading to a narrow resonance at an energy of about 0.1 MeV. We investigate the EFT

  12. Matting of Hair Due to Halo-egg Shampoo

    Directory of Open Access Journals (Sweden)

    Z M Mani

    1983-01-01

    Full Text Available A case of hair matting in an 18 year old female is reported. The hair got densely entangled immediately after washing the hair with ′Halo Egg′ shampoo. The hair was disentangled completely after prolonged dipping of the hair in arachis oil frr 5 days.

  13. A galaxy-halo model for multiple cosmological tracers

    Science.gov (United States)

    Bull, Philip

    2017-10-01

    The information extracted from large galaxy surveys with the likes of DES, DESI, Euclid, LSST, SKA, and WFIRST will be greatly enhanced if the resultant galaxy catalogues can be cross-correlated with one another. Predicting the nature of the information gain, and developing the tools to realize it, depends on establishing a consistent model of how the galaxies detected by each survey trace the same underlying matter distribution. Existing analytic methods, such as halo occupation distribution modelling, are not well suited for this task, and can suffer from ambiguities and tuning issues when applied to multiple tracers. In this paper, we take the first step towards constructing an alternative that provides a common model for the connection between galaxies and dark matter haloes across a wide range of wavelengths (and thus tracer populations). This is based on a chain of parametrized statistical distributions that model the connection between (I) halo mass and bulk physical properties of galaxies, such as star formation rate; and (II) those same physical properties and a variety of emission processes. The result is a flexible parametric model that allows analytic halo model calculations of one-point functions to be carried out for multiple tracers, as well as providing semi realistic galaxy properties for fast mock catalogue generation.

  14. Giant Radio Halos in Galaxy Clusters as Probes of Particle ...

    Indian Academy of Sciences (India)

    Giant radio halos in galaxy clusters probe mechanisms of particle acceleration connected with cluster merger events. Shocks and turbulence are driven in the inter-galactic medium (IGM) during clusters mergers and may have a deep impact on the non-thermal properties of galaxy clusters. Models of turbulent ...

  15. Inheritance of halo blight resistance in common bean | Chataika ...

    African Journals Online (AJOL)

    Halo blight caused by (Pseudomonas syringe pv. phaseolicola (Burkh) (Psp)) is an important disease of common bean (Phaseolus vulgaris L.) world-wide. Several races of the Psp exist and likewise some sources of resistance in common bean have been identified. CAL 143, is a CIAT-bred common bean line, which was ...

  16. DM haloes in the fifth-force cosmology

    NARCIS (Netherlands)

    Hellwing, Wojciech A.; Cautun, Marius; Knebe, Alexander; Juszkiewicz, Roman; Knollmann, Steffen

    2013-01-01

    We investigate how long-range scalar interactions affect the properties of dark matter haloes. For doing so we employ the ReBEL model which implements an additional interaction between dark matter particles. On the phenomenological level this is equivalent to a modification of gravity. We analyse

  17. Prospects for detecting supersymmetric dark matter in the Galactic halo.

    Science.gov (United States)

    Springel, V; White, S D M; Frenk, C S; Navarro, J F; Jenkins, A; Vogelsberger, M; Wang, J; Ludlow, A; Helmi, A

    2008-11-06

    Dark matter is the dominant form of matter in the Universe, but its nature is unknown. It is plausibly an elementary particle, perhaps the lightest supersymmetric partner of known particle species. In this case, annihilation of dark matter in the halo of the Milky Way should produce gamma-rays at a level that may soon be observable. Previous work has argued that the annihilation signal will be dominated by emission from very small clumps (perhaps smaller even than the Earth), which would be most easily detected where they cluster together in the dark matter haloes of dwarf satellite galaxies. Here we report that such small-scale structure will, in fact, have a negligible impact on dark matter detectability. Rather, the dominant and probably most easily detectable signal will be produced by diffuse dark matter in the main halo of the Milky Way. If the main halo is strongly detected, then small dark matter clumps should also be visible, but may well contain no stars, thereby confirming a key prediction of the cold dark matter model.

  18. Is the halo responsible for the microlensing events?

    CERN Document Server

    Roulet, E.; Giudice, G.F.

    1994-01-01

    Abstract: We discuss whether the astrophysical objects responsible for the recently reported microlensing events of sources in the Large Magellanic Cloud can be identified as the brown dwarf components of the spheroid of our galaxy, rather than the constituents of a dark baryonic halo.

  19. Lensing effects of misaligned disks in dark matter halos

    NARCIS (Netherlands)

    Quadri, R.; Möller, O.; Natarajan, P.

    2002-01-01

    Published in: Astrophys. J. 597 (2003) 659-671 citations recorded in [Science Citation Index] Abstract: We study the observational signatures of the lensing signal produced by dark matter halos with embedded misaligned disks. This issue is of particular interest at the present time since most of the

  20. Spin alignment of dark matter haloes in filaments and walls

    NARCIS (Netherlands)

    Aragón-Calvo, M. A.; Weygaert, R. van de; Jones, B. J. T.; Hulst, T. van der

    2006-01-01

    Abstract: The MMF technique is used to segment the cosmic web as seen in a cosmological N-body simulation into wall-like and filament-like structures. We find that the spins and shapes of dark matter haloes are significantly correlated with each other and with the orientation of their host

  1. Spin alignment of dark matter halos in filaments and walls

    NARCIS (Netherlands)

    Aragon-Calvo, Miguel A.; van de Weygaert, Rien; Jones, Bernard J. T.; van der Hulst, J. M.

    2007-01-01

    The MMF technique is used to segment the cosmic web as seen in a cosmological N-body simulation into wall-like and filament-like structures. We find that the spins and shapes of dark matter halos are significantly correlated with each other and with the orientation of their host structures. The

  2. Fast weak-lensing simulations with halo model

    Science.gov (United States)

    Giocoli, Carlo; Di Meo, Sandra; Meneghetti, Massimo; Jullo, Eric; de la Torre, Sylvain; Moscardini, Lauro; Baldi, Marco; Mazzotta, Pasquale; Metcalf, R. Benton

    2017-09-01

    Full ray-tracing maps of gravitational lensing, constructed from N-body simulations, represent a fundamental tool to interpret present and future weak-lensing data. However, the limitation of computational resources and storage capabilities severely restricts the number of realizations that can be performed in order to accurately sample both the cosmic shear models and covariance matrices. In this paper, we present a halo model formalism for weak gravitational lensing that alleviates these issues by producing weak-lensing mocks at a reduced computational cost. Our model takes as input the halo population within a desired light cone and the linear power spectrum of the underlined cosmological model. We examine the contribution given by the presence of substructures within haloes to the cosmic shear power spectrum and quantify it to the percent level. Our method allows us to reconstruct high-resolution convergence maps, for any desired source redshifts, of light cones that realistically trace the matter density distribution in the universe, account for masked area and sample selections. We compare our analysis on the same large-scale structures constructed using ray-tracing techniques and find very good agreements in both the linear and non-linear regimes up to few percent levels. The accuracy and speed of our method demonstrate the potential of our halo model for weak-lensing statistics and the possibility to generate a large sample of convergence maps for different cosmological models as needed for the analysis of large galaxy redshift surveys.

  3. Giant Radio Halos in Galaxy Clusters as Probes of Particle ...

    Indian Academy of Sciences (India)

    Abstract. Giant radio halos in galaxy clusters probe mechanisms of particle acceleration connected with cluster merger events. Shocks and turbulence are driven in the inter-galactic medium (IGM) during clusters mergers and may have a deep impact on the non-thermal properties of galaxy clusters. Models of turbulent ...

  4. Cosmic Rays in the Disk and Halo of Galaxies

    Science.gov (United States)

    Dogiel, V. A.; Breitschwerdt, D.

    2012-09-01

    We give a review of cosmic ray propagation models. It is shown that the development of the theory of cosmic ray origin leads inevitably to the conclusion that cosmic ray propagation in the Galaxy is determined by effective particle scattering, which is described by spatial diffusion. The Galactic Disk is surrounded by an extended halo, in which cosmic rays are confined before escaping into intergalactic space. For a long time cosmic ray convective outflow from the Galaxy (galactic wind) was believed to be insignificant. However, investigations of hydrodynamic stability and an analysis of ISM dynamics (including cosmic rays) showed that a galactic wind was emanating near the disk, and accelerating towards the halo, reaching its maximum velocity far away from the disk. Therefore convective cosmic ray transport should be important in galactic halos. Recent analysis of the gamma-ray emissivity in the Galactic disk of EGRET data, which showed that cosmic rays are more or less uniformly distributed in the radial direction of the disk, as well as the interpretation of soft X-ray emission in galactic halos, give convincing evidence of the existence of a galactic wind in star forming galaxies.

  5. Network selection, Information filtering and Scalable computation

    Science.gov (United States)

    Ye, Changqing

    -complete factorizations, possibly with a high percentage of missing values. This promotes additional sparsity beyond rank reduction. Computationally, we design methods based on a ``decomposition and combination'' strategy, to break large-scale optimization into many small subproblems to solve in a recursive and parallel manner. On this basis, we implement the proposed methods through multi-platform shared-memory parallel programming, and through Mahout, a library for scalable machine learning and data mining, for mapReduce computation. For example, our methods are scalable to a dataset consisting of three billions of observations on a single machine with sufficient memory, having good timings. Both theoretical and numerical investigations show that the proposed methods exhibit significant improvement in accuracy over state-of-the-art scalable methods.

  6. Using a laser range finder mounted on a MicroVision robot to estimate environmental parameters

    Science.gov (United States)

    Fehr, Duc; Papanikolopoulos, Nikos

    2009-05-01

    In this article we will present a new robot (MicroVision) that has been designed at the University of Minnesota (UMN), Center for Distributed Robotics. Its design reminds of the designs of previous robots built at the UMN such as the COTS Scouts or the eROSIs. It is composed of a body with two wheels and a tail just like the two aforementioned robots. However, the MicroVision has more powerful processing and sensing capabilities and we utilized these to compute areas in the surrounding environment by using a convex hull approach. We are trying to estimate the projected area of an object onto the ground. This is done by the computation of convex hulls that are based on the data received from the MicroVision's laser range finder. Although localization of the robot is an important feature in being able to compute these convex hulls, localization and mapping techniques are only used as a tool and are not an end in this work. The main idea of this work is to demonstrate the ability of the laser carrying MicroVision robot to move around an object in order to get a scan from each side. From these scans, the convex hull of the shape is deduced and its projected area onto the ground is estimated.

  7. Phase-shift correlation method for accurate phase difference estimation in range finder.

    Science.gov (United States)

    Liu, Yu-Zhou; Zhao, Bin

    2015-04-10

    High-precision phase-difference measurement is a key technology for a phase-shift laser range finder. In order to improve the estimation accuracy of phase difference between two sinusoidal signals with identical frequency, the phase-shift correlation method is described. Theoretical analysis shows that the conventional cross-correlation method will bring notable deviations when the true phase difference is close to 0° or 180° in the presence of noise. For reducing the influence of noise, two step calculations--phase-shift autocorrelation and phase-shift cross correlation--are used in the phase-shift correlation method. The estimation bias is eliminated by phase-shift autocorrelation in which the autocorrelation is calculated between the 2π phase-shifted signal and the original signal, and the periodic errors are eliminated by phase-shift cross correlation in which the phase difference is estimated when the true phase difference is near 90° or 270°. The effect of frequency drift on the phase difference is also discussed. The experiment results show that the maximum error of the conventional method is about 0.15°, while the estimation error of our proposed method is much less than 0.01° under the same conditions.

  8. FINDER, A system providing complex decision support for commercial transport replanning operations

    Science.gov (United States)

    Bittermann, Vincent; Deker, Guy; Sassus, Pierre; Mielnik, Jean-Christophe; Jud, Jean-Marie

    1994-03-01

    Decision-aid systems, likely to appear in future aircraft generations, could play a central role in the cockpit thanks to the broad spectrum of functionalities and decision support facilities they will offer to the crew. As part of such systems, the exploratory FINDER mock-up is a knowledge based system (KBS) designed to help crew members continually optimize their flight plan by suggesting solutions considering exhaustive information related to flight context, either on pilot request or upon external information occurrence. The successful evaluation by Air France pilots of that first mock-up dedicated to diversion procedure on pilot request has led to the current development of an enhanced system with nominal enroute operations and real-time capabilities. Nominal enroute operations concern the optimization with respect to an evolutive constraining of favoring environment (due to weather, traffic or regulated areas, and ETOPS constraints). This study paves the way for a future flight assistant system concept which is already under investigation and may take place in SEXTANT Avionique's future development steps.

  9. Can a More User-Friendly Medicare Plan Finder Improve Consumers' Selection of Medicare Plans?

    Science.gov (United States)

    Martino, Steven C; Kanouse, David E; Miranda, David J; Elliott, Marc N

    2017-10-01

    To evaluate the efficacy for consumers of two potential enhancements to the Medicare Plan Finder (MPF)-a simplified data display and a "quick links" home page designed to match the specific tasks that users seek to accomplish on the MPF. Participants (N = 641) were seniors and adult caregivers of seniors who were recruited from a national online panel. Participants browsed a simulated version of the MPF, made a hypothetical plan choice, and reported on their experience. Participants were randomly assigned to one of eight conditions in a fully factorial design: 2 home pages (quick links, current MPF home page) × 2 data displays (simplified, current MPF display) × 2 plan types (stand-alone prescription drug plan [PDP], Medicare Advantage plan with prescription drug coverage [MA-PD]). The quick links page resulted in more favorable perceptions of the MPF, improved users' understanding of the information, and increased the probability of choosing the objectively best plan. The simplified data display resulted in a more favorable evaluation of the website, better comprehension of the displayed information, and, among those choosing a PDP only, an increased probability of choosing the best plan. Design enhancements could markedly improve average website users' understanding, ability to use, and experience of using the MPF. © Health Research and Educational Trust.

  10. Lightning Radio Source Retrieval Using Advanced Lightning Direction Finder (ALDF) Networks

    Science.gov (United States)

    Koshak, William J.; Blakeslee, Richard J.; Bailey, J. C.

    1998-01-01

    A linear algebraic solution is provided for the problem of retrieving the location and time of occurrence of lightning ground strikes from an Advanced Lightning Direction Finder (ALDF) network. The ALDF network measures field strength, magnetic bearing and arrival time of lightning radio emissions. Solutions for the plane (i.e., no Earth curvature) are provided that implement all of tile measurements mentioned above. Tests of the retrieval method are provided using computer-simulated data sets. We also introduce a quadratic planar solution that is useful when only three arrival time measurements are available. The algebra of the quadratic root results are examined in detail to clarify what portions of the analysis region lead to fundamental ambiguities in source location. Complex root results are shown to be associated with the presence of measurement errors when the lightning source lies near an outer sensor baseline of the ALDF network. In the absence of measurement errors, quadratic root degeneracy (no source location ambiguity) is shown to exist exactly on the outer sensor baselines for arbitrary non-collinear network geometries. The accuracy of the quadratic planar method is tested with computer generated data sets. The results are generally better than those obtained from the three station linear planar method when bearing errors are about 2 deg. We also note some of the advantages and disadvantages of these methods over the nonlinear method of chi(sup 2) minimization employed by the National Lightning Detection Network (NLDN) and discussed in Cummins et al.(1993, 1995, 1998).

  11. Exploration tools for drug discovery and beyond: applying SciFinder to interdisciplinary research.

    Science.gov (United States)

    Haldeman, Margaret; Vieira, Barbara; Winer, Fred; Knutsen, Lars J S

    2005-06-01

    Chemists have long recognized the value of online databases for surveying the literature of their field. Chemical Abstracts Service (CAS) databases covering almost a century's worth of journal articles and patent documents are among the best known and widely used for searching information on compounds. Today's research presents a new challenge, however, as the boundaries of chemistry and biological sciences overlap increasingly. This trend is especially true in the drug discovery field where published findings relating to both chemical and biological entities and their interactions are examined. CAS has expanded its resources to meet the requirements of the new, interdisciplinary challenges faced by today's researchers. This is evident both in the content of CAS databases, which have been expanded to include more biology-related information, and in the technology of the search tools now available to researchers on their desktop. It is the integration of content and search-and-retrieval technology that enables new insights to be made in the vast body of accumulated information. CAS's SciFinder is a widely used research tool for this purpose.

  12. Recognition of flow in everyday life using sensor agent robot with laser range finder

    Science.gov (United States)

    Goshima, Misa; Mita, Akira

    2011-04-01

    In the present paper, we suggest an algorithm for a sensor agent robot with a laser range finder to recognize the flows of residents in the living spaces in order to achieve flow recognition in the living spaces, recognition of the number of people in spaces, and the classification of the flows. House reform is or will be demanded to prolong the lifetime of the home. Adaption for the individuals is needed for our aging society which is growing at a rapid pace. Home autonomous mobile robots will become popular in the future for aged people to assist them in various situations. Therefore we have to collect various type of information of human and living spaces. However, a penetration in personal privacy must be avoided. It is essential to recognize flows in everyday life in order to assist house reforms and aging societies in terms of adaption for the individuals. With background subtraction, extra noise removal, and the clustering based k-means method, we got an average accuracy of more than 90% from the behavior from 1 to 3 persons, and also confirmed the reliability of our system no matter the position of the sensor. Our system can take advantages from autonomous mobile robots and protect the personal privacy. It hints at a generalization of flow recognition methods in the living spaces.

  13. HGT-Finder: A New Tool for Horizontal Gene Transfer Finding and Application to Aspergillus genomes.

    Science.gov (United States)

    Nguyen, Marcus; Ekstrom, Alex; Li, Xueqiong; Yin, Yanbin

    2015-10-09

    Horizontal gene transfer (HGT) is a fast-track mechanism that allows genetically unrelated organisms to exchange genes for rapid environmental adaptation. We developed a new phyletic distribution-based software, HGT-Finder, which implements a novel bioinformatics algorithm to calculate a horizontal transfer index and a probability value for each query gene. Applying this new tool to the Aspergillus fumigatus, Aspergillus flavus, and Aspergillus nidulans genomes, we found 273, 542, and 715 transferred genes (HTGs), respectively. HTGs have shorter length, higher guanine-cytosine (GC) content, and relaxed selection pressure. Metabolic process and secondary metabolism functions are significantly enriched in HTGs. Gene clustering analysis showed that 61%, 41% and 74% of HTGs in the three genomes form physically linked gene clusters (HTGCs). Overlapping manually curated, secondary metabolite gene clusters (SMGCs) with HTGCs found that 9 of the 33 A. fumigatus SMGCs and 31 of the 65 A. nidulans SMGCs share genes with HTGCs, and that HTGs are significantly enriched in SMGCs. Our genome-wide analysis thus presented very strong evidence to support the hypothesis that HGT has played a very critical role in the evolution of SMGCs. The program is freely available at http://cys.bios.niu.edu/HGTFinder/ HGTFinder.tar.gz.

  14. Forest Fire Finder - DOAS application to long-range forest fire detection

    Science.gov (United States)

    Valente de Almeida, Rui; Vieira, Pedro

    2017-06-01

    Fires are an important factor in shaping Earth's ecosystems. Plant and animal life, in almost every land habitat, are at least partially dependent on the effects of fire. However, their destructive force, which has often proven uncontrollable, is one of our greatest concerns, effectively resulting in several policies in the most important industrialised regions of the globe. This paper aims to comprehensively characterise the Forest Fire Finder (FFF), a forest fire detection system based mainly upon a spectroscopic technique called differential optical absorption spectroscopy (DOAS). The system is designed and configured with the goal of detecting higher-than-the-horizon smoke columns by measuring and comparing scattered sunlight spectra. The article covers hardware and software, as well as their interactions and specific algorithms for day mode operation. An analysis of data retrieved from several installations deployed in the course of the last 5 years is also presented. Finally, this paper features a discussion on the most prominent future improvements planned for the system, as well as its ramifications and adaptations, such as a thermal imaging system for short-range fire seeking or environmental quality control.

  15. Parallel 4-Dimensional Cellular Automaton Track Finder for the CBM Experiment

    Science.gov (United States)

    Akishina, Valentina; Kisel, Ivan

    2016-10-01

    The CBM experiment (FAIR/GSI, Darmstadt, Germany) will focus on the measurement of rare probes at interaction rates up to 10 MHz with data flow of up to 1 TB/s. It requires a novel read-out and data-acquisition concept with self-triggered electronics and free-streaming data. In this case resolving different collisions is not a trivial task and event building must be performed in software online. That requires full online event reconstruction and selection not only in space, but also in time, so-called 4D event building and selection. This is a task of the First-Level Event Selection (FLES). The FLES reconstruction and selection package consists of several modules: track finding, track fitting, short-lived particles finding, event building and event selection. The Cellular Automaton (CA) track finder algorithm was adapted towards time-slice-based reconstruction and included into the CBMROOT framework. In this article, we describe the modification done to the algorithm, as well as the performance of the developed time-based approach.

  16. Yale Image Finder (YIF): a new search engine for retrieving biomedical images

    Science.gov (United States)

    Xu, Songhua; McCusker, James; Krauthammer, Michael

    2008-01-01

    Summary: Yale Image Finder (YIF) is a publicly accessible search engine featuring a new way of retrieving biomedical images and associated papers based on the text carried inside the images. Image queries can also be issued against the image caption, as well as words in the associated paper abstract and title. A typical search scenario using YIF is as follows: a user provides few search keywords and the most relevant images are returned and presented in the form of thumbnails. Users can click on the image of interest to retrieve the high resolution image. In addition, the search engine will provide two types of related images: those that appear in the same paper, and those from other papers with similar image content. Retrieved images link back to their source papers, allowing users to find related papers starting with an image of interest. Currently, YIF has indexed over 140 000 images from over 34 000 open access biomedical journal papers. Availability: http://krauthammerlab.med.yale.edu/imagefinder/ Contact: michael.krauthammer@yale.edu PMID:18614584

  17. Implementation of the data acquisition system for the Overlap Modular Track Finder in the CMS experiment

    CERN Document Server

    Zabolotny, Wojciech; Bunkowski, Karol; Byszuk, Adrian Pawel; Dobosz, Jakub; Doroba, Krzysztof; Pawel Drabik; Gorski, Maciej; Kalinowski, Artur; Kierzkowski, Krzysztof Zdzislaw; Konecki, Marcin Andrzej; Oklinski, Wojciech; Olszewski, Michal; Pozniak, Krzysztof Tadeusz; Zawistowski, Krystian

    2016-01-01

    The CMS experiment is currently undergoing the upgrade of its trigger, including the Level-1 muon trigger. In the barrel-endcap transition region the Overlap Muon Track Finder (OMTF) combines data from three types of detectors (RPC, DT, and CSC) to find the muon candidates.To monitor the operation of the OMTF, it is important to receive the data which were the basis for the trigger decision. This task must be performed by the Data Acquisition (OMTF DAQ) system.The new MTCA technology applied in the updated trigger allows implementation of the OMTF DAQ together with the OMTF trigger in the MTF7 board. Further concentration of data is performed by standard AMC13 boards.The proposed data concentration methodology assumes parallel filtering and queuing of data arriving from all input links (24 RPC, 30 CSC, and 6 DT). The data are waiting for the trigger decision in the input buffers. The triggered data are then converted into the intermediate 72-bit format and put into the sorter queues. The block responsible for...

  18. Bayesian network feature finder (BANFF): an R package for gene network feature selection.

    Science.gov (United States)

    Lan, Zhou; Zhao, Yize; Kang, Jian; Yu, Tianwei

    2016-12-01

    Network marker selection on genome-scale networks plays an important role in the understanding of biological mechanisms and disease pathologies. Recently, a Bayesian nonparametric mixture model has been developed and successfully applied for selecting genes and gene sub-networks. Hence, extending this method to a unified approach for network-based feature selection on general large-scale networks and creating an easy-to-use software package is on demand. We extended the method and developed an R package, the Bayesian network feature finder (BANFF), providing a package of posterior inference, model comparison and graphical illustration of model fitting. The model was extended to a more general form, and a parallel computing algorithm for the Markov chain Monte Carlo -based posterior inference and an expectation maximization-based algorithm for posterior approximation were added. Based on simulation studies, we demonstrate the use of BANFF on analyzing gene expression on a protein-protein interaction network. https://cran.r-project.org/web/packages/BANFF/index.html CONTACT: jiankang@umich.edu, tianwei.yu@emory.eduSupplementary information: Supplementary data are available at Bioinformatics online. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  19. The halo sign: HRCT findings in 85 patients.

    Science.gov (United States)

    Alves, Giordano Rafael Tronco; Marchiori, Edson; Irion, Klaus; Nin, Carlos Schuler; Watte, Guilherme; Pasqualotto, Alessandro Comarú; Severo, Luiz Carlos; Hochhegger, Bruno

    2016-01-01

    The halo sign consists of an area of ground-glass opacity surrounding pulmonary lesions on chest CT scans. We compared immunocompetent and immunosuppressed patients in terms of halo sign features and sought to identify those of greatest diagnostic value. This was a retrospective study of CT scans performed at any of seven centers between January of 2011 and May of 2015. Patients were classified according to their immune status. Two thoracic radiologists reviewed the scans in order to determine the number of lesions, as well as their distribution, size, and contour, together with halo thickness and any other associated findings. Of the 85 patients evaluated, 53 were immunocompetent and 32 were immunosuppressed. Of the 53 immunocompetent patients, 34 (64%) were diagnosed with primary neoplasm. Of the 32 immunosuppressed patients, 25 (78%) were diagnosed with aspergillosis. Multiple and randomly distributed lesions were more common in the immunosuppressed patients than in the immunocompetent patients (p Pacientes imunocompetentes e imunodeprimidos foram comparados quanto a características do sinal do halo a fim de identificar as de maior valor diagnóstico. Estudo retrospectivo de tomografias realizadas em sete centros entre janeiro de 2011 e maio de 2015. Os pacientes foram classificados de acordo com seu estado imunológico. Dois radiologistas torácicos analisaram os exames a fim de determinar o número de lesões e sua distribuição, tamanho e contorno, bem como a espessura do halo e quaisquer outros achados associados. Dos 85 pacientes avaliados, 53 eram imunocompetentes e 32 eram imunodeprimidos. Dos 53 pacientes imunocompetentes, 34 (64%) receberam diagnóstico de neoplasia primária. Dos 32 pacientes imunodeprimidos, 25 (78%) receberam diagnóstico de aspergilose. Lesões múltiplas e distribuídas aleatoriamente foram mais comuns nos imunodeprimidos do que nos imunocompetentes (p pacientes imunocompetentes são bastante diferentes das observadas em

  20. Scalable Transactions for Web Applications in the Cloud

    NARCIS (Netherlands)

    Zhou, W.; Pierre, G.E.O.; Chi, C.-H.

    2009-01-01

    Cloud Computing platforms provide scalability and high availability properties for web applications but they sacrifice data consistency at the same time. However, many applications cannot afford any data inconsistency. We present a scalable transaction manager for NoSQL cloud database services to

  1. New Complexity Scalable MPEG Encoding Techniques for Mobile Applications

    Directory of Open Access Journals (Sweden)

    Stephan Mietens

    2004-03-01

    Full Text Available Complexity scalability offers the advantage of one-time design of video applications for a large product family, including mobile devices, without the need of redesigning the applications on the algorithmic level to meet the requirements of the different products. In this paper, we present complexity scalable MPEG encoding having core modules with modifications for scalability. The interdependencies of the scalable modules and the system performance are evaluated. Experimental results show scalability giving a smooth change in complexity and corresponding video quality. Scalability is basically achieved by varying the number of computed DCT coefficients and the number of evaluated motion vectors but other modules are designed such they scale with the previous parameters. In the experiments using the “Stefan” sequence, the elapsed execution time of the scalable encoder, reflecting the computational complexity, can be gradually reduced to roughly 50% of its original execution time. The video quality scales between 20 dB and 48 dB PSNR with unity quantizer setting, and between 21.5 dB and 38.5 dB PSNR for different sequences targeting 1500 kbps. The implemented encoder and the scalability techniques can be successfully applied in mobile systems based on MPEG video compression.

  2. Scalable DeNoise-and-Forward in Bidirectional Relay Networks

    DEFF Research Database (Denmark)

    Sørensen, Jesper Hemming; Krigslund, Rasmus; Popovski, Petar

    2010-01-01

    In this paper a scalable relaying scheme is proposed based on an existing concept called DeNoise-and-Forward, DNF. We call it Scalable DNF, S-DNF, and it targets the scenario with multiple communication flows through a single common relay. The idea of the scheme is to combine packets at the relay...

  3. Building scalable apps with Redis and Node.js

    CERN Document Server

    Johanan, Joshua

    2014-01-01

    If the phrase scalability sounds alien to you, then this is an ideal book for you. You will not need much Node.js experience as each framework is demonstrated in a way that requires no previous knowledge of the framework. You will be building scalable Node.js applications in no time! Knowledge of JavaScript is required.

  4. The Concept of Business Model Scalability

    DEFF Research Database (Denmark)

    Nielsen, Christian; Lund, Morten

    2015-01-01

    are leveraged in this value creation, delivery and realization exercise. Central to the mainstream understanding of business models is the value proposition towards the customer and the hypothesis generated is that if the firm delivers to the customer what he/she requires, then there is a good foundation......The power of business models lies in their ability to visualize and clarify how firms’ may configure their value creation processes. Among the key aspects of business model thinking are a focus on what the customer values, how this value is best delivered to the customer and how strategic partners...... for a long-term profitable business. However, the message conveyed in this article is that while providing a good value proposition may help the firm ‘get by’, the really successful businesses of today are those able to reach the sweet-spot of business model scalability. This article introduces and discusses...

  5. Towards scalable Byzantine fault-tolerant replication

    Science.gov (United States)

    Zbierski, Maciej

    2017-08-01

    Byzantine fault-tolerant (BFT) replication is a powerful technique, enabling distributed systems to remain available and correct even in the presence of arbitrary faults. Unfortunately, existing BFT replication protocols are mostly load-unscalable, i.e. they fail to respond with adequate performance increase whenever new computational resources are introduced into the system. This article proposes a universal architecture facilitating the creation of load-scalable distributed services based on BFT replication. The suggested approach exploits parallel request processing to fully utilize the available resources, and uses a load balancer module to dynamically adapt to the properties of the observed client workload. The article additionally provides a discussion on selected deployment scenarios, and explains how the proposed architecture could be used to increase the dependability of contemporary large-scale distributed systems.

  6. A graph algebra for scalable visual analytics.

    Science.gov (United States)

    Shaverdian, Anna A; Zhou, Hao; Michailidis, George; Jagadish, Hosagrahar V

    2012-01-01

    Visual analytics (VA), which combines analytical techniques with advanced visualization features, is fast becoming a standard tool for extracting information from graph data. Researchers have developed many tools for this purpose, suggesting a need for formal methods to guide these tools' creation. Increased data demands on computing requires redesigning VA tools to consider performance and reliability in the context of analysis of exascale datasets. Furthermore, visual analysts need a way to document their analyses for reuse and results justification. A VA graph framework encapsulated in a graph algebra helps address these needs. Its atomic operators include selection and aggregation. The framework employs a visual operator and supports dynamic attributes of data to enable scalable visual exploration of data.

  7. Declarative and Scalable Selection for Map Visualizations

    DEFF Research Database (Denmark)

    Kefaloukos, Pimin Konstantin Balic

    foreground layers is merited. (2) The typical map making professional has changed from a GIS specialist to a busy person with map making as a secondary skill. Today, thematic maps are produced by journalists, aid workers, amateur data enth siasts, and scientists alike. Therefore it is crucial...... that this diverse group of map makers is provided with easy-to-use and expressible thematic map design tools. Such tools should support customized selection of data for maps in scenarios where developer time is a scarce resource. (3) The Web provides access to massive data repositories for thematic maps...... based on an access log of recent requests. The results show that Glossy SQL og CVL can be used to compute cartographic selection by processing one or more complex queries in a relational database. The scalability of the approach has been verified up to half a million objects in the database. Furthermore...

  8. Efficient protein knockdown of HaloTag-fused proteins using hybrid molecules consisting of IAP antagonist and HaloTag ligand.

    Science.gov (United States)

    Tomoshige, Shusuke; Hashimoto, Yuichi; Ishikawa, Minoru

    2016-07-15

    We previously reported a protein knockdown system for HaloTag-fused proteins using hybrid small molecules consisting of alkyl chloride, which binds covalently to HaloTag, linked to BE04 (2), a bestatin (3) derivative with an affinity for cellular inhibitor of apoptosis protein 1 (cIAP1, a kind of ubiquitin ligase). This system addressed several limitations of prior protein knockdown technology, and was applied to degrade two HaloTag-fused proteins. However, the degradation activity of these hybrid small molecules was not potent. Therefore, we set out to improve this system. We report here the design, synthesis and biological evaluation of novel hybrid compounds 4a and 4b consisting of alkyl chloride linked to IAP antagonist MV1 (5). Compounds 4a and 4b were confirmed to reduce the levels of HaloTag-fused tumor necrosis factor α (HaloTag-TNFα), HaloTag-fused cell division control protein 42 (HaloTag-Cdc42), and unfused HaloTag protein in living cells more potently than did BE04-linked compound 1b. Analysis of the mode of action revealed that the reduction of HaloTag-TNFα is proteasome-dependent, and is also dependent on the linker structure between MV1 (5) and alkyl chloride. These compounds appear to induce ubiquitination at the HaloTag moiety of HaloTag-fused proteins. Our results indicate that these newly synthesized MV1-type hybrid compounds, 4a and 4b, are efficient tools for protein knockdown for HaloTag-fused proteins. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Scalable and Media Aware Adaptive Video Streaming over Wireless Networks

    Science.gov (United States)

    Tizon, Nicolas; Pesquet-Popescu, Béatrice

    2008-12-01

    This paper proposes an advanced video streaming system based on scalable video coding in order to optimize resource utilization in wireless networks with retransmission mechanisms at radio protocol level. The key component of this system is a packet scheduling algorithm which operates on the different substreams of a main scalable video stream and which is implemented in a so-called media aware network element. The concerned type of transport channel is a dedicated channel subject to parameters (bitrate, loss rate) variations on the long run. Moreover, we propose a combined scalability approach in which common temporal and SNR scalability features can be used jointly with a partitioning of the image into regions of interest. Simulation results show that our approach provides substantial quality gain compared to classical packet transmission methods and they demonstrate how ROI coding combined with SNR scalability allows to improve again the visual quality.

  10. Constraints on the Formation of M31’s Stellar Halo from the SPLASH Survey

    Directory of Open Access Journals (Sweden)

    Karoline Gilbert

    2017-09-01

    Full Text Available The SPLASH (Spectroscopic and Photometric Landscape of Andromeda’s Stellar Halo Survey has observed fields throughout M31’s stellar halo, dwarf satellites, and stellar disk. The observations and derived measurements have either been compared to predictions from simulations of stellar halo formation or modeled directly in order to derive inferences about the formation and evolution of M31’s stellar halo. We summarize some of the major results from the SPLASH survey and the resulting implications for our understanding of the build-up of M31’s stellar halo.

  11. A Phenomenological Model of Star Formation Efficiency in Dark Matter Halos

    Science.gov (United States)

    Finnegan, Daniel; Alsheshakly, Ghadeer; Moustakas, John

    2018-01-01

    The efficiency of star formation in massive dark matter halos is extraordinarily low, less than 10% in >10^13 Msun sized halos. Although many physical processes have been proposed to explain this low efficiency, such as feedback from supermassive black halos and massive stars, this question remains one of the most important outstanding problems in galaxy evolution. To explore this problem, we build a simple phenomenological model to predict the variations in gas fraction and star formation efficiency as a function of halo mass. We compare our model predictions to central galaxy stellar masses and halo masses drawn from the literature, and discuss plans for our future work.

  12. ZOMG - III. The effect of halo assembly on the satellite population

    Science.gov (United States)

    Garaldi, Enrico; Romano-Díaz, Emilio; Borzyszkowski, Mikolaj; Porciani, Cristiano

    2018-01-01

    We use zoom hydrodynamical simulations to investigate the properties of satellites within galaxy-sized dark-matter haloes with different assembly histories. We consider two classes of haloes at redshift z = 0: 'stalled' haloes that assembled at z > 1 and 'accreting' ones that are still forming nowadays. Previously, we showed that the stalled haloes are embedded within thick filaments of the cosmic web, while the accreting ones lie where multiple thin filaments converge. We find that satellites in the two classes have both similar and different properties. Their mass spectra, radial count profiles, baryonic and stellar content, and the amount of material they shed are indistinguishable. However, the mass fraction locked in satellites is substantially larger for the accreting haloes as they experience more mergers at late times. The largest difference is found in the satellite kinematics. Substructures fall towards the accreting haloes along quasi-radial trajectories whereas an important tangential velocity component is developed, before accretion, while orbiting the filament that surrounds the stalled haloes. Thus, the velocity anisotropy parameter of the satellites (β) is positive for the accreting haloes and negative for the stalled ones. This signature enables us to tentatively categorize the Milky Way halo as stalled based on a recent measurement of β. Half of our haloes contain clusters of satellites with aligned orbital angular momenta corresponding to flattened structures in space. These features are not driven by baryonic physics and are only found in haloes hosting grand-design spiral galaxies, independently of their assembly history.

  13. Detection of Hot Halo Gets Theory Out of Hot Water

    Science.gov (United States)

    2006-02-01

    Scientists using NASA's Chandra X-ray Observatory have detected an extensive halo of hot gas around a quiescent spiral galaxy. This discovery is evidence that galaxies like our Milky Way are still accumulating matter from the gradual inflow of intergalactic gas. "What we are likely witnessing here is the ongoing galaxy formation process," said Kristian Pedersen of the University of Copenhagen, Denmark, and lead author of a report on the discovery. Chandra observations show that the hot halo extends more than 60,000 light years on either side of the disk of the galaxy known as NGC 5746. The detection of such a large halo alleviates a long-standing problem for the theory of galaxy formation. Spiral galaxies are thought to form from enormous clouds of intergalactic gas that collapse to form giant, spinning disks of stars and gas. Chandra X-ray Image of NGC 5746 Chandra X-ray Image of NGC 5746 One prediction of this theory is that large spiral galaxies should be immersed in halos of hot gas left over from the galaxy formation process. Hot gas has been detected around spiral galaxies in which vigorous star formation is ejecting matter from the galaxy, but until now hot halos due to infall of intergalactic matter have not been detected. "Our observations solve the mystery of the missing hot halos around spiral galaxies," said Pedersen. "The halos exist, but are so faint that an extremely sensitive telescope such as Chandra is needed to detect them." DSS Optical Image of NGC 5746 DSS Optical Image of NGC 5746 NGC 5746 is a massive spiral galaxy about a 100 million light years from Earth. Its disk of stars and gas is viewed almost edge-on. The galaxy shows no signs of unusual star formation, or energetic activity from its nuclear region, making it unlikely that the hot halo is produced by gas flowing out of the galaxy. "We targeted NGC 5746 because we thought its distance and orientation would give us the best chance to detect a hot halo caused by the infall of

  14. Halo histories versus Galaxy properties at z = 0 - I. The quenching of star formation

    Science.gov (United States)

    Tinker, Jeremy L.; Wetzel, Andrew R.; Conroy, Charlie; Mao, Yao-Yuan

    2017-12-01

    We test whether halo age and galaxy age are correlated at fixed halo and galaxy mass. The formation histories, and thus ages, of dark matter haloes correlate with their large-scale density ρ, an effect known as assembly bias. We test whether this correlation extends to galaxies by measuring the dependence of galaxy stellar age on ρ. To clarify the comparison between theory and observation, and to remove the strong environmental effects on satellites, we use galaxy group catalogues to identify central galaxies and measure their quenched fraction, fQ, as a function of large-scale environment. Models that match halo age to central galaxy age predict a strong positive correlation between fQ and ρ. However, we show that the amplitude of this effect depends on the definition of halo age: assembly bias is significantly reduced when removing the effects of splashback haloes - those haloes that are central but have passed through a larger halo or experienced strong tidal encounters. Defining age using halo mass at its peak value rather than current mass removes these effects. In Sloan Digital Sky Survey data, at M* ≳ 1010 M⊙ h-2, there is a ∼5 per cent increase in fQ from low-to-high densities, which is in agreement with predictions of dark matter haloes using peak halo mass. At lower stellar mass there is little to no correlation of fQ with ρ. For these galaxies, age matching is inconsistent with the data across the range of halo formation metrics that we tested. This implies that halo formation history has a small but statistically significant impact on quenching of star formation at high masses, while the quenching process in low-mass central galaxies is uncorrelated with halo formation history.

  15. Moving-mesh cosmology: characteristics of galaxies and haloes

    Science.gov (United States)

    Kereš, Dušan; Vogelsberger, Mark; Sijacki, Debora; Springel, Volker; Hernquist, Lars

    2012-09-01

    We discuss cosmological hydrodynamic simulations of galaxy formation performed with the new moving-mesh code AREPO, which promises higher accuracy compared with the traditional smoothed particle hydrodynamics (SPH) technique that has been widely employed for this problem. In this exploratory study, we deliberately limit the complexity of the physical processes followed by the code for ease of comparison with previous calculations, and include only cooling of gas with a primordial composition, heating by a spatially uniform ultraviolet background, and a simple subresolution model for regulating star formation in the dense interstellar medium. We use an identical set of physics in corresponding simulations carried out with the well-tested SPH code GADGET, adopting also the same high-resolution gravity solver. We are thus able to compare both simulation sets on an object-by-object basis, allowing us to cleanly isolate the impact of different hydrodynamical methods on galaxy and halo properties. In accompanying papers, Vogelsberger et al. and Sijacki et al., we focus on an analysis of the global baryonic statistics predicted by the simulation codes, and complementary idealized simulations that highlight the differences between the hydrodynamical schemes. Here we investigate their influence on the baryonic properties of simulated galaxies and their surrounding haloes. We find that AREPO leads to significantly higher star formation rates for galaxies in massive haloes and to more extended gaseous discs in galaxies, which also feature a thinner and smoother morphology than their GADGET counterparts. Consequently, galaxies formed in AREPO have larger sizes and higher specific angular momentum than their SPH correspondents. Interestingly, the more efficient cooling flows in AREPO yield higher densities and lower entropies in halo centres compared to GADGET, whereas the opposite trend is found in halo outskirts. The cooling differences leading to higher star formation rates

  16. Factors Influencing Depression Endpoints Research (FINDER: baseline results of Italian patients with depression

    Directory of Open Access Journals (Sweden)

    Grassi Luigi

    2009-05-01

    Full Text Available Abstract Background Factors Influencing Depression Endpoints Research (FINDER is a 6-month, prospective, observational study carried out in 12 European countries aimed at investigating health-related quality of life (HRQoL in outpatients receiving pharmacological treatment for a first or new depressive episode. Baseline characteristics of patients enrolled in Italy are presented. Methods All treatment decisions were at the discretion of the investigator. Data were collected at baseline and after 3 and 6 months of treatment. Baseline evaluations included demographics, medical and psychiatric history, and medications used in the last 24 months and prescribed at enrolment. The Hospital Anxiety and Depression Scale (HADS, was adopted to evaluate depressive symptoms, while somatic and painful physical symptoms were assessed by using the Somatic Symptom Inventory (SSI and a 0 to 100 mm visual analogue scale (VAS, HRQoL via 36-item Short Form Health Survey (SF-36, and the European Quality of Life 5-Dimensions (EQ-5D instrument. Results A total of 513 patients were recruited across 38 sites. The mean ± standard deviation (SD age at first depressive episode was 38.7 ± 15.9 years, the mean duration of depression 10.6 ± 12.3 years. The most common psychiatric comorbidities in the previous 24 months were anxiety/panic (72.6% and obsessive/compulsive disorders (13.4%, while 35.9% had functional somatic syndromes. Most patients (65.1% reported pain from any cause. Monotherapy with selective serotonin reuptake inhibitors (SSRIs and tricyclic antidepressants (TCAs was prescribed at enrolment in 64.5% and 6.4% of the cases, respectively. The most commonly prescribed agents were sertraline (17.3%, escitalopram (16.2%, venlaflaxine (15.6% and paroxetine (14.8%. The mean HADS subscores for depression and anxiety were 13.3 ± 4.2 and 12.2 ± 3.9, respectively; 76.4% of patients could be defined as being 'probable cases' for depression and 66.2% for anxiety. The

  17. Development and validation of the Overlap Muon Track Finder for the CMS experiment

    Science.gov (United States)

    Dobosz, J.; Mietki, P.; Zawistowski, K.; Żarnecki, G.

    2016-09-01

    Present article is a description of the authors contribution in upgrade and analysis of performance of the Level-1 Muon Trigger of the CMS experiment. The authors are students of University of Warsaw and Gdansk University of Technology. They are collaborating with the CMS Warsaw Group. This article summarises students' work presented during the Students session during the Workshop XXXVIII-th IEEE-SPIE Joint Symposium Wilga 2016. In the first section the CMS experiment is briefly described and the importance of the trigger system is explained. There is also shown basic difference between old muon trigger strategy and the upgraded one. The second section is devoted to Overlap Muon Track Finder (OMTF). This is one of the crucial components of the Level-1 Muon Trigger. The algorithm of OMTF is described. In the third section there is discussed one of the event selection aspects - cut on the muon transverse momentum pT . Sometimes physical muon with pT bigger than a certain threshold is unnecessarily cut and physical muon with lower pT survives. To improve pT selection modified algorithm was proposed and its performance was studied. One of the features of the OMTF is that one physical muon often results in several muon candidates. The Ghost-Buster algorithm is designed to eliminate surplus candidates. In the fourth section this algorithm and its performance on different data samples are discussed. In the fifth section Local Data Acquisition System (Local DAQ) is briefly described. It supports initial system commissioning. The test done with OMTF Local DAQ are described. In the sixth section there is described development of web application used for the control and monitoring of CMS electronics. The application provides access to graphical user interface for manual control and the connection to the CMS hierarchical Run Control.

  18. Theory and modelling of the magnetic field measurement in LISA PathFinder

    Energy Technology Data Exchange (ETDEWEB)

    Diaz-Aguilo, M; Garcia-Berro, E [Departament de Fisica Aplicada, Universitat Politecnica de Catalunya, c/Esteve Terrades, 5, 08860 Castelldefels (Spain); Lobo, A, E-mail: marc.diaz.aguilo@fa.upc.ed [Institut d' Estudis Espacials de Catalunya, c/Gran Capita 2-4, Edif. Nexus 104, 08034 Barcelona (Spain)

    2010-02-07

    The magnetic diagnostics subsystem of the LISA Technology Package (LTP) on board the LISA PathFinder (LPF) spacecraft includes a set of four tri-axial fluxgate magnetometers, intended to measure with high precision the magnetic field at their respective positions. However, their readouts do not provide a direct measurement of the magnetic field at the positions of the test masses, and hence an interpolation method must be designed and implemented to obtain the values of the magnetic field at these positions. However, such an interpolation process faces serious difficulties. Indeed, the size of the interpolation region is excessive for a linear interpolation to be reliable while, on the other hand, the number of magnetometer channels do not provide sufficient data to go beyond the linear approximation. We describe an alternative method to address this issue, by means of neural network algorithms. The key point in this approach is the ability of neural networks to learn from suitable training data representing the behaviour of the magnetic field. Despite the relatively large distance between the test masses and the magnetometers, and the insufficient number of data channels, we find that our artificial neural network algorithm is able to reduce the estimation errors of the field and gradient down to levels below 10%, a quite satisfactory result. Learning efficiency can be best improved by making use of data obtained in on-ground measurements prior to mission launch in all relevant satellite locations and in real operation conditions. Reliable information on that appears to be essential for a meaningful assessment of magnetic noise in the LTP.

  19. AsteroidFinder - the space-borne telescope to search for NEO Asteroids

    Science.gov (United States)

    Hartl, M.; Mosebach, H.; Schubert, J.; Michaelis, H.; Mottola, S.; Kührt, E.; Schindler, K.

    2017-11-01

    This paper presents the mission profile as well as the optical configuration of the space-borne AsteroidFinder telescope. Its main objective is to retrieve asteroids with orbits interior to the earth's orbit. The instrument requires high sensitivity to detect asteroids with a limiting magnitude of equal or larger than 18.5mag (V-Band) and astrometric accuracy of 1arcsec (1σ). This requires a telescope aperture greater than 400cm2, high image stability, detector with high quantum efficiency (peak > 90%) and very low noise, which is only limited by zodiacal background. The telescope will observe the sky between 30° and 60° in solar elongation. The telescope optics is based on a Cook type TMA. An effective 2°×2° field of view (FOV) is achieved by a fast F/3.4 telescope with near diffraction-limited performance. The absence of centre obscuration or spiders in combination with an accessible intermediate field plane and exit pupil allow for efficient stray light mitigation. Design drivers for the telescope are the required point spread function (PSF) values, an extremely efficient stray light suppression (due to the magnitude requirement mentioned above), the detector performance, and the overall optical and mechanical stability for all orientations of the satellite. To accommodate the passive thermal stabilization scheme and the necessary structural stability, the materials selection for the telescope main structure and the mirrors are of vital importance. A focal plane with four EMCCD detectors is envisaged. The EMCCD technology features shorter integration times, which is in favor regarding the pointing performance of the satellite. The launch of the mission is foreseen for the year 2013 with a subsequent mission lifetime of at least 1 year.

  20. Efficient α, β-motif finder for identification of phenotype-related functional modules

    Directory of Open Access Journals (Sweden)

    Schmidt Matthew C

    2011-11-01

    Full Text Available Abstract Background Microbial communities in their natural environments exhibit phenotypes that can directly cause particular diseases, convert biomass or wastewater to energy, or degrade various environmental contaminants. Understanding how these communities realize specific phenotypic traits (e.g., carbon fixation, hydrogen production is critical for addressing health, bioremediation, or bioenergy problems. Results In this paper, we describe a graph-theoretical method for in silico prediction of the cellular subsystems that are related to the expression of a target phenotype. The proposed (α, β-motif finder approach allows for identification of these phenotype-related subsystems that, in addition to metabolic subsystems, could include their regulators, sensors, transporters, and even uncharacterized proteins. By comparing dozens of genome-scale networks of functionally associated proteins, our method efficiently identifies those statistically significant functional modules that are in at least α networks of phenotype-expressing organisms but appear in no more than β networks of organisms that do not exhibit the target phenotype. It has been shown via various experiments that the enumerated modules are indeed related to phenotype-expression when tested with different target phenotypes like hydrogen production, motility, aerobic respiration, and acid-tolerance. Conclusion Thus, we have proposed a methodology that can identify potential statistically significant phenotype-related functional modules. The functional module is modeled as an (α, β-clique, where α and β are two criteria introduced in this work. We also propose a novel network model, called the two-typed, divided network. The new network model and the criteria make the problem tractable even while very large networks are being compared. The code can be downloaded from http://www.freescience.org/cs/ABClique/

  1. Unsynchronized scanning with a low-cost laser range finder for real-time range imaging

    Science.gov (United States)

    Hatipoglu, Isa; Nakhmani, Arie

    2017-06-01

    Range imaging plays an essential role in many fields: 3D modeling, robotics, heritage, agriculture, forestry, reverse engineering. One of the most popular range-measuring technologies is laser scanner due to its several advantages: long range, high precision, real-time measurement capabilities, and no dependence on lighting conditions. However, laser scanners are very costly. Their high cost prevents widespread use in applications. Due to the latest developments in technology, now, low-cost, reliable, faster, and light-weight 1D laser range finders (LRFs) are available. A low-cost 1D LRF with a scanning mechanism, providing the ability of laser beam steering for additional dimensions, enables to capture a depth map. In this work, we present an unsynchronized scanning with a low-cost LRF to decrease scanning period and reduce vibrations caused by stop-scan in synchronized scanning. Moreover, we developed an algorithm for alignment of unsynchronized raw data and proposed range image post-processing framework. The proposed technique enables to have a range imaging system for a fraction of the price of its counterparts. The results prove that the proposed method can fulfill the need for a low-cost laser scanning for range imaging for static environments because the most significant limitation of the method is the scanning period which is about 2 minutes for 55,000 range points (resolution of 250x220 image). In contrast, scanning the same image takes around 4 minutes in synchronized scanning. Once faster, longer range, and narrow beam LRFs are available, the methods proposed in this work can produce better results.

  2. Oracle database performance and scalability a quantitative approach

    CERN Document Server

    Liu, Henry H

    2011-01-01

    A data-driven, fact-based, quantitative text on Oracle performance and scalability With database concepts and theories clearly explained in Oracle's context, readers quickly learn how to fully leverage Oracle's performance and scalability capabilities at every stage of designing and developing an Oracle-based enterprise application. The book is based on the author's more than ten years of experience working with Oracle, and is filled with dependable, tested, and proven performance optimization techniques. Oracle Database Performance and Scalability is divided into four parts that enable reader

  3. A novel 3D scalable video compression algorithm

    Science.gov (United States)

    Somasundaram, Siva; Subbalakshmi, Koduvayur P.

    2003-05-01

    In this paper we propose a scalable video coding scheme that utilizes the embedded block coding with optimal truncation (EBCOT) compression algorithm. Three dimensional spatio-temporal decomposition of the video sequence succeeded by compression using the EBCOT generates a SNR and resolution scalable bit stream. The proposed video coding algorithm not only performs closer to the MPEG-4 video coding standard in compression efficiency but also provides better SNR and resolution scalability. Experimental results show that the performance of the proposed algorithm does better than the 3-D SPIHT (Set Partitioning in Hierarchial Trees) algorithm by 1.5dB.

  4. Proton halos in the 1 s0 d shell

    Science.gov (United States)

    Brown, B. A.; Hansen, P. G.

    1996-02-01

    The shell-model properties of proton halo states in proton-rich 1 s0 d shell nuclei are investigated. The most interesting cases appear to be those in 26,27P and 27S. The parallel-momentum distributions of core fragments from proton stripping reactions may provide experimental insight into the structure of the halo states and the role played by the reaction mechanism. The “generalized Coulomb shift”, defined as the difference between the neutron and proton separation energies for an analogue pair, is shown to vary smoothly as a function of proton-separation energy and provides a good tool for mass extrapolations. The relation between the total interaction cross section and the matter radius is discussed.

  5. Galactic Halo Wormhole Solutions in f(T Gravity

    Directory of Open Access Journals (Sweden)

    M. Sharif

    2014-01-01

    Full Text Available The proposal of galactic halo region is based on the idea that dark halos contain some characteristics needed to support traversable wormhole solutions. We explore wormhole solutions in this region in the framework of generalized teleparallel gravity. We consider static spherically symmetric wormhole spacetime with flat galactic rotational curves and obtain expressions of matter components for nondiagonal tetrad. The effective energy-momentum tensor leads to the violation of energy conditions which may impose condition on the normal matter to satisfy these conditions. We take two well-known f(T models in exponential and logarithmic forms to discuss wormhole solutions as well as the equilibrium condition. It is concluded that wormhole solutions violating weak energy condition are obtained for both models with stable configuration.

  6. Two distinct halo populations in the solar neighborhood. III

    DEFF Research Database (Denmark)

    Schuster, W. J.; Moreno, E.; Nissen, Poul Erik

    2012-01-01

    Context. In Papers I and II of this series, we have found clear indications of the existence of two distinct populations of stars in the solar neighborhood belonging to the metal-rich end of the halo metallicity distribution function. Based on high-resolution, high S/N spectra, it is possible...... to distinguish between “high-alpha” and “low-alpha” components using the [α/Fe] versus [Fe/H] diagram. Aims. Precise relative ages and orbital parameters are determined for 67 halo and 16 thick-disk stars having metallicities in the range −1.4 ... populations in the formation and evolution of the Galaxy. Methods. Ages are derived by comparing the positions of stars in the log Teff–log g diagram with isochrones from the Y2 models interpolated to the exact [Fe/H] and [α/Fe] values of each star. The stellar parameters have been adopted from the preceding...

  7. Relativistic Hartree-Bogoliubov description of the halo nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Meng, J.; Ring, P. [Universitaet Muenchen, Garching (Germany)

    1996-12-31

    Here the authors report the development of the relativistic Hartree-Bogoliubov theory in coordinate space. Pairing correlations are taken into account by both density dependent force of zero range and finite range Gogny force. As a primary application the relativistic HB theory is used to describe the chain of Lithium isotopes reaching from {sup 6}Li to {sup 11}Li. In contrast to earlier investigations within a relativistic mean field theory and a density dependent Hartree Fock theory, where the halo in {sup 11}Li could only be reproduced by an artificial shift of the 1p{sub 1/2} level close to the continuum limit, the halo is now reproduced in a self-consistent way without further modifications using the scattering of Cooper pairs to the 2s{sub 1/2} level in the continuum. Excellent agreement with recent experimental data is observed.

  8. The abundance of boron in three halo stars

    Science.gov (United States)

    Duncan, Douglas K.; Lambert, David L.; Lemke, Michael

    1992-01-01

    B abundances for three halo stars: HD 140283, HD 19445, and HD 201891 are presented. Using recent determinations of the Be abundance in HD 140283, B/Be of 10 +5/-4 is found for this star, and similar ratios are inferred for HD 19445 and HD 201891. This ratio is equal to the minimum value of 10 expected from a synthesis of B and Be by high-energy cosmic-ray spallation reactions in the interstellar medium. It is shown that the accompanying synthesis of Li by alpha on alpha fusion reactions is probably a minor contributor to the observed 'primordial' Li of halo stars. The observed constant ratios of B/O and Be/O are expected if the principal channel of synthesis involves cosmic-ray CNO nuclei from the supernovae colliding with interstellar protons.

  9. Toward a combined SAGE II-HALOE aerosol climatology: an evaluation of HALOE version 19 stratospheric aerosol extinction coefficient observations

    Directory of Open Access Journals (Sweden)

    L. W. Thomason

    2012-09-01

    Full Text Available Herein, the Halogen Occultation Experiment (HALOE aerosol extinction coefficient data is evaluated in the low aerosol loading period after 1996 as the first necessary step in a process that will eventually allow the production of a combined HALOE/SAGE II (Stratospheric Aerosol and Gas Experiment aerosol climatology of derived aerosol products including surface area density. Based on these analyses, it is demonstrated that HALOE's 3.46 μm is of good quality above 19 km and suitable for scientific applications above that altitude. However, it is increasingly suspect at lower altitudes and should not be used below 17 km under any circumstances after 1996. The 3.40 μm is biased by about 10% throughout the lower stratosphere due to the failure to clear NO2 but otherwise appears to be a high quality product down to 15 km. The 2.45 and 5.26 μm aerosol extinction coefficient measurements are clearly biased and should not be used for scientific applications after the most intense parts of the Pinatubo period. Many of the issues in the aerosol data appear to be related to either the failure to clear some interfering gas species or doing so poorly. For instance, it is clear that the 3.40 μm aerosol extinction coefficient measurements can be improved through the inclusion of an NO2 correction and could, in fact, end up as the highest quality overall HALOE aerosol extinction coefficient measurement. It also appears that the 2.45 and 5.26 μm channels may be improved by updating the Upper Atmosphere Pilot Database which is used as a resource for the removal of gas species otherwise not available from direct HALOE measurements. Finally, a simple model to demonstrate the promise of mixed visible/infrared aerosol extinction coefficient ensembles for the retrieval of bulk aerosol properties demonstrates that a combined HALOE/SAGE II aerosol climatology is feasible and may represent a substantial improvement over independently derived

  10. Are the supergiant halos experimental evidence for the pionic radioactivity?

    Science.gov (United States)

    Ion, D. B.; Ion-Mihai, R.

    1994-10-01

    Pionic radiohalos (PIRH), as an integral time record of the pionic nuclear radioactivity of the heavy nuclides with Z > 80 from the inclusions from ancient minerals, are introduced. It is then shown that the essential characteristic features of the observed supergiant halos (SGH) are reproduced with a surprisingly high accuracy by those of the pionic radiohalos. For the clarification of this problem new experimental investigations including pionic detection methods are suggested.

  11. Mapping Milky Way Halo Structure with Blue Horizontal Branch Stars

    Science.gov (United States)

    Martin, Charles; Newberg, Heidi Jo; Carlin, Jeffrey L.

    2017-01-01

    The use of blue horizontal brach (BHB) and red giant branch stars as tracers of stellar debris streams is a common practice and has been useful in the confirmation of kinematic properties of previously identified streams. This work explores less common ways of untangling the velocity signatures of streams traveling radially to our line of sight, and to peer toward the higher density region of the Galactic Center using data from the Sloan Digital Sky Survey (SDSS). Using spectra of BHB stars, we are able to kinematically distinguish moving groups in the Milky Way halo. The results of this thesis advance our knowledge of the following stellar halo substructures: the Pisces Stellar Stream, the Hercules-Aquila Cloud, the Hercules Halo Stream, and the Hermus Stream. A study of red giant stars led to the kinematic discovery of the Pisces Stellar Stream. Red giant stars were also examined to determine that the previously identified velocity signature that was suggested for the Hercules-Aquila Cloud was due to disk star contamination and errors in preliminary SDSS velocities. The Hercules Halo Stream is a previously unidentified structure that could be related to the Hercules-Aquila Cloud, and was discovered as a velocity excess of SDSS BHB stars. We identify a group of 10 stars with similar velocities that are spatially coincident with the Hermus Stream. An orbit is fit to the Hermus Stream that rules out a connection with the Phoenix Stream.This work was supported by NSF grants AST 09-37523, 14-09421, 16-15688, the NASA/NY Space Grant fellowship, and contributions made by The Marvin Clan, Babette Josephs, Manit Limlamai, and the 2015 Crowd Funding Campaign to Support Milky Way Research.

  12. The Connection between Radio Halos and Cluster Mergers and the ...

    Indian Academy of Sciences (India)

    and the Statistical Properties of the Radio Halo Population. R. Cassano1,2,∗. , G. Brunetti2 & T. ... sources located in the cluster central regions, with spatial extent similar to that of the hot ICM and steep radio spectra, α > 1.1 ... distribution of clusters in the P1.4 − LX diagram (Brunetti et al. 2007): RH trace the well-known ...

  13. Can $\\beta$-decay probe excited state halos?

    CERN Multimedia

    2002-01-01

    In the first experiment at the newly constructed ISOLDE Facility the first-forbidden $\\beta$-decay of $^{17}$Ne into the first excited state of $^{17}$F has been measured. It is a factor two faster than the corresponding mirror decay and thus gives one of the largest recorded asymmetries for $\\beta$-decays feeding bound final states. Shell-model calculations can only reproduce the asymmetry if the halo structure of the $^{17}$F state is taken into account.

  14. A multi-machine scaling of halo current rotation

    Science.gov (United States)

    Myers, C. E.; Eidietis, N. W.; Gerasimov, S. N.; Gerhardt, S. P.; Granetz, R. S.; Hender, T. C.; Pautasso, G.; Contributors, JET

    2018-01-01

    Halo currents generated during unmitigated tokamak disruptions are known to develop rotating asymmetric features that are of great concern to ITER because they can dynamically amplify the mechanical stresses on the machine. This paper presents a multi-machine analysis of these phenomena. More specifically, data from C-Mod, NSTX, ASDEX Upgrade, DIII-D, and JET are used to develop empirical scalings of three key quantities: (1) the machine-specific minimum current quench time, \

  15. A look into the inside of haloes: a characterization of the halo shape as a function of overdensity in the Planck cosmology

    Science.gov (United States)

    Despali, Giulia; Giocoli, Carlo; Bonamigo, Mario; Limousin, Marceau; Tormen, Giuseppe

    2017-04-01

    In this paper, we study the triaxial properties of dark matter haloes of a wide range of masses extracted from a set of cosmological N-body simulations. We measure the shape at different distances from the halo centre (characterized by different overdensity thresholds), both in three and in two dimensions. We discuss how halo triaxiality increases with mass, redshift and distance from the halo centre. We also examine how the orientations of the different ellipsoids are aligned with each other and what is the gradient in internal shapes for haloes with different virial configurations. Our findings highlight that the internal part of the halo retains memory of the violent formation process keeping the major axis oriented towards the preferential direction of the infalling material while the outer part becomes rounder due to continuous isotropic merging events. This effect is clearly evident in high-mass haloes - which formed more recently - while it is more blurred in low-mass haloes. We present simple distributions that may be used as priors for various mass reconstruction algorithms, operating in different wavelengths, in order to recover a more complex and realistic dark matter distribution of isolated and relaxed systems.

  16. Scalable, remote administration of Windows NT.

    Energy Technology Data Exchange (ETDEWEB)

    Gomberg, M.; Stacey, C.; Sayre, J.

    1999-06-08

    In the UNIX community there is an overwhelming perception that NT is impossible to manage remotely and that NT administration doesn't scale. This was essentially true with earlier versions of the operating system. Even today, out of the box, NT is difficult to manage remotely. Many tools, however, now make remote management of NT not only possible, but under some circumstances very easy. In this paper we discuss how we at Argonne's Mathematics and Computer Science Division manage all our NT machines remotely from a single console, with minimum locally installed software overhead. We also present NetReg, which is a locally developed tool for scalable registry management. NetReg allows us to apply a registry change to a specified set of machines. It is a command line utility that can be run in either interactive or batch mode and is written in Perl for Win32, taking heavy advantage of the Win32::TieRegistry module.

  17. Scalable conditional induction variables (CIV) analysis

    KAUST Repository

    Oancea, Cosmin E.

    2015-02-01

    Subscripts using induction variables that cannot be expressed as a formula in terms of the enclosing-loop indices appear in the low-level implementation of common programming abstractions such as Alter, or stack operations and pose significant challenges to automatic parallelization. Because the complexity of such induction variables is often due to their conditional evaluation across the iteration space of loops we name them Conditional Induction Variables (CIV). This paper presents a flow-sensitive technique that summarizes both such CIV-based and affine subscripts to program level, using the same representation. Our technique requires no modifications of our dependence tests, which is agnostic to the original shape of the subscripts, and is more powerful than previously reported dependence tests that rely on the pairwise disambiguation of read-write references. We have implemented the CIV analysis in our parallelizing compiler and evaluated its impact on five Fortran benchmarks. We have found that that there are many important loops using CIV subscripts and that our analysis can lead to their scalable parallelization. This in turn has led to the parallelization of the benchmark programs they appear in.

  18. Scalable Notch Antenna System for Multiport Applications

    Directory of Open Access Journals (Sweden)

    Abdurrahim Toktas

    2016-01-01

    Full Text Available A novel and compact scalable antenna system is designed for multiport applications. The basic design is built on a square patch with an electrical size of 0.82λ0×0.82λ0 (at 2.4 GHz on a dielectric substrate. The design consists of four symmetrical and orthogonal triangular notches with circular feeding slots at the corners of the common patch. The 4-port antenna can be simply rearranged to 8-port and 12-port systems. The operating band of the system can be tuned by scaling (S the size of the system while fixing the thickness of the substrate. The antenna system with S: 1/1 in size of 103.5×103.5 mm2 operates at the frequency band of 2.3–3.0 GHz. By scaling the antenna with S: 1/2.3, a system of 45×45 mm2 is achieved, and thus the operating band is tuned to 4.7–6.1 GHz with the same scattering characteristic. A parametric study is also conducted to investigate the effects of changing the notch dimensions. The performance of the antenna is verified in terms of the antenna characteristics as well as diversity and multiplexing parameters. The antenna system can be tuned by scaling so that it is applicable to the multiport WLAN, WIMAX, and LTE devices with port upgradability.

  19. Scalable inference for stochastic block models

    KAUST Repository

    Peng, Chengbin

    2017-12-08

    Community detection in graphs is widely used in social and biological networks, and the stochastic block model is a powerful probabilistic tool for describing graphs with community structures. However, in the era of "big data," traditional inference algorithms for such a model are increasingly limited due to their high time complexity and poor scalability. In this paper, we propose a multi-stage maximum likelihood approach to recover the latent parameters of the stochastic block model, in time linear with respect to the number of edges. We also propose a parallel algorithm based on message passing. Our algorithm can overlap communication and computation, providing speedup without compromising accuracy as the number of processors grows. For example, to process a real-world graph with about 1.3 million nodes and 10 million edges, our algorithm requires about 6 seconds on 64 cores of a contemporary commodity Linux cluster. Experiments demonstrate that the algorithm can produce high quality results on both benchmark and real-world graphs. An example of finding more meaningful communities is illustrated consequently in comparison with a popular modularity maximization algorithm.

  20. A Programmable, Scalable-Throughput Interleaver

    Directory of Open Access Journals (Sweden)

    Rijshouwer EJC

    2010-01-01

    Full Text Available The interleaver stages of digital communication standards show a surprisingly large variation in throughput, state sizes, and permutation functions. Furthermore, data rates for 4G standards such as LTE-Advanced will exceed typical baseband clock frequencies of handheld devices. Multistream operation for Software Defined Radio and iterative decoding algorithms will call for ever higher interleave data rates. Our interleave machine is built around 8 single-port SRAM banks and can be programmed to generate up to 8 addresses every clock cycle. The scalable architecture combines SIMD and VLIW concepts with an efficient resolution of bank conflicts. A wide range of cellular, connectivity, and broadcast interleavers have been mapped on this machine, with throughputs up to more than 0.5 Gsymbol/second. Although it was designed for channel interleaving, the application domain of the interleaver extends also to Turbo interleaving. The presented configuration of the architecture is designed as a part of a programmable outer receiver on a prototype board. It offers (near universal programmability to enable the implementation of new interleavers. The interleaver measures 2.09 m in 65 nm CMOS (including memories and proves functional on silicon.

  1. SCTP as scalable video coding transport

    Science.gov (United States)

    Ortiz, Jordi; Graciá, Eduardo Martínez; Skarmeta, Antonio F.

    2013-12-01

    This study presents an evaluation of the Stream Transmission Control Protocol (SCTP) for the transport of the scalable video codec (SVC), proposed by MPEG as an extension to H.264/AVC. Both technologies fit together properly. On the one hand, SVC permits to split easily the bitstream into substreams carrying different video layers, each with different importance for the reconstruction of the complete video sequence at the receiver end. On the other hand, SCTP includes features, such as the multi-streaming and multi-homing capabilities, that permit to transport robustly and efficiently the SVC layers. Several transmission strategies supported on baseline SCTP and its concurrent multipath transfer (CMT) extension are compared with the classical solutions based on the Transmission Control Protocol (TCP) and the Realtime Transmission Protocol (RTP). Using ns-2 simulations, it is shown that CMT-SCTP outperforms TCP and RTP in error-prone networking environments. The comparison is established according to several performance measurements, including delay, throughput, packet loss, and peak signal-to-noise ratio of the received video.

  2. Scalable Combinatorial Tools for Health Disparities Research

    Directory of Open Access Journals (Sweden)

    Michael A. Langston

    2014-10-01

    Full Text Available Despite staggering investments made in unraveling the human genome, current estimates suggest that as much as 90% of the variance in cancer and chronic diseases can be attributed to factors outside an individual’s genetic endowment, particularly to environmental exposures experienced across his or her life course. New analytical approaches are clearly required as investigators turn to complicated systems theory and ecological, place-based and life-history perspectives in order to understand more clearly the relationships between social determinants, environmental exposures and health disparities. While traditional data analysis techniques remain foundational to health disparities research, they are easily overwhelmed by the ever-increasing size and heterogeneity of available data needed to illuminate latent gene x environment interactions. This has prompted the adaptation and application of scalable combinatorial methods, many from genome science research, to the study of population health. Most of these powerful tools are algorithmically sophisticated, highly automated and mathematically abstract. Their utility motivates the main theme of this paper, which is to describe real applications of innovative transdisciplinary models and analyses in an effort to help move the research community closer toward identifying the causal mechanisms and associated environmental contexts underlying health disparities. The public health exposome is used as a contemporary focus for addressing the complex nature of this subject.

  3. Scalability and interoperability within glideinWMS

    Energy Technology Data Exchange (ETDEWEB)

    Bradley, D.; /Wisconsin U., Madison; Sfiligoi, I.; /Fermilab; Padhi, S.; /UC, San Diego; Frey, J.; /Wisconsin U., Madison; Tannenbaum, T.; /Wisconsin U., Madison

    2010-01-01

    Physicists have access to thousands of CPUs in grid federations such as OSG and EGEE. With the start-up of the LHC, it is essential for individuals or groups of users to wrap together available resources from multiple sites across multiple grids under a higher user-controlled layer in order to provide a homogeneous pool of available resources. One such system is glideinWMS, which is based on the Condor batch system. A general discussion of glideinWMS can be found elsewhere. Here, we focus on recent advances in extending its reach: scalability and integration of heterogeneous compute elements. We demonstrate that the new developments exceed the design goal of over 10,000 simultaneous running jobs under a single Condor schedd, using strong security protocols across global networks, and sustaining a steady-state job completion rate of a few Hz. We also show interoperability across heterogeneous computing elements achieved using client-side methods. We discuss this technique and the challenges in direct access to NorduGrid and CREAM compute elements, in addition to Globus based systems.

  4. Decay Properties of the Halo Nucleus $^{11}$Li

    CERN Multimedia

    2002-01-01

    During the past years a considerable experimental effort has been devoted to the production and study of nuclei close to the neutron and proton drip-lines. The most spectacular phenomenon encountered is the occurrence of neutron halos in the loosely bound neutron rich nuclei. \\\\ \\\\ Another interesting feature, observed at ISOLDE, which most likely is connected to the halo structure, is the very strong (super-allowed) Gamow-Teller $\\beta$- transitions to highly excited states which are systematically observed for the lightest neutron rich drip-line nuclei. These transitions might be viewed as arising from the quasi-free $\\beta$ -decay of the halo neutrons. It is proposed to make a detailed study of the $\\beta$- strength function for $^{11}$Li, a nuclide having a half-life of 8.2 ms and a Q $\\beta$-value of 20.73~MeV. \\\\ \\\\ So far only a lower limit of the Gamow-Teller transition rate to highly excited states ($\\approx$~18.5~MeV) in the daughter nucleus has been obtained from measurements of $\\beta$-delayed tri...

  5. KINEMATICS OF OUTER HALO GLOBULAR CLUSTERS IN M31

    Energy Technology Data Exchange (ETDEWEB)

    Veljanoski, J.; Ferguson, A. M. N.; Bernard, E. J.; Penarrubia, J. [Institute for Astronomy, University of Edinburgh, Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ (United Kingdom); Mackey, A. D. [Research School of Astronomy and Astrophysics, Australian National University, Mt Stromlo Observatory, Weston Creek, ACT 2611 (Australia); Huxor, A. P. [Astronomisches Rechen-Institut, Zentrum fur Astronomie der Universitat Heidelberg, Monchhofstr. 12-14, D-69120 Heidelberg (Germany); Irwin, M. J.; Chapman, S. C. [Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA (United Kingdom); Cote, P. [NRC Herzberg Institute of Astrophysics, 5071 West Saanich Road, Victoria, British Columbia V9E 2E7 (Canada); Tanvir, N. R.; McConnachie, A. [Department of Physics and Astronomy, University of Leicester, Leicester LE1 7RH (United Kingdom); Ibata, R. A.; Martin, N. F. [Observatoire de Strasbourg, 11 rue de l' Universite, F-67000 Strasbourg (France); Fardal, M. [University of Massachusetts, Department of Astronomy, LGRT 619-E, 710 N. Pleasant Street, Amherst, MA 01003-9305 (United States); Lewis, G. F. [Institute of Astronomy, School of Physics, University of Sydney, NSW 2006 (Australia)

    2013-05-10

    We present the first kinematic analysis of the far outer halo globular cluster (GC) population in the Local Group galaxy M31. Our sample contains 53 objects with projected radii of {approx}20-130 kpc, 44 of which have no previous spectroscopic information. GCs with projected radii {approx}> 30 kpc are found to exhibit net rotation around the minor axis of M31, in the same sense as the inner GCs, albeit with a smaller amplitude of 79 {+-} 19 km s{sup -1}. The rotation-corrected velocity dispersion of the full halo GC sample is 106 {+-} 12 km s{sup -1}, which we observe to decrease with increasing projected radius. We find compelling evidence for kinematic coherence among GCs that project on top of halo substructure, including a clear signature of infall for GCs lying along the northwest stream. Using the tracer mass estimator, we estimate the dynamical mass of M31 within 200 kpc to be M{sub M31} = (1.2-1.5) {+-} 0.2 Multiplication-Sign 10{sup 12} M{sub Sun }. This value is highly dependent on the chosen model and assumptions within.

  6. Hypervelocity Stars: From the Galactic Center to the Halo

    Science.gov (United States)

    Kenyon, Scott J.; Bromley, Benjamin C.; Geller, Margaret J.; Brown, Warren R.

    2008-06-01

    Hypervelocity stars (HVSs) traverse the Galaxy from the central black hole to the outer halo. We show that the Galactic potential within 200 pc acts as a high-pass filter preventing low-velocity HVSs from reaching the halo. To trace the orbits of HVSs throughout the Galaxy, we construct two forms of the potential which reasonably represent the observations in the range 5-105 pc: a simple spherically symmetric model and a bulge-disk-halo model. We use the Hills mechanism (disruption of binaries by the tidal field of the central black hole) to inject HVSs into the Galaxy and to compute the observable spatial and velocity distributions of HVSs with masses in the range 0.6-4 M⊙. These distributions reflect the mass function in the Galactic center, properties of binaries in the Galactic center, and aspects of stellar evolution and the injection mechanism. For 0.6-4 M⊙ main-sequence stars, the fraction of unbound HVSs and the asymmetry of the velocity distribution for their bound counterparts increase with stellar mass. The density profiles for unbound HVSs decline with distance from the Galactic center approximately as r-2 (but are steeper for the most massive stars, which evolve off the main sequence during their travel time from the Galactic center); the density profiles for the bound ejecta decline with distance approximately as r-3. In a survey with a limiting magnitude of Vlesssim 23, the detectability of HVSs (unbound or bound) increases with stellar mass.

  7. Integrated Marketing Communications (IMC di PT Halo Rumah Bernyanyi

    Directory of Open Access Journals (Sweden)

    Rebekka Rismayanti

    2017-01-01

    Full Text Available Abstract: This research aims to describe the effectiveness of Integrated Marketing Communication (IMC in PT Halo Rumah Bernyanyi which, from the perspective of marketing strategy, could be studied by analyzing the segmentation, targeting, and positioning. Using case-study method with in-depth interview, the result shows that the implementation of IMC at PT Halo Rumah Bernyayi is arranged in one single strategy and tend to neglect the complexities of running multi-brand family karaoke-house. This considers as ineffective because it leads to “cannibalization” among brands, especially when costumer’s targetting is overlooked before drafting the IMC plan. Keywords: Business, Integrated Marketing Communication, Marketing   Abstrak: Penelitian ini bertujuan untuk mendeskripsikan efektivitas penerapan Integrated Marketing Communications (IMC yang dilihat dari aspek segmentation, targeting dan positioning. Metode penelitian adalah studi kasus dengan menggunakan wawancara mendalam. Hasil penelitian menunjukkan bahwa penerapan IMC di PT Halo Rumah Bernyanyi dibuat dalam satu strategi dan tidak memerhatikan kompleksitas dari aspek segmentation, targeting dan positioning sebagai pedoman dasar. Langkah tersebut dinilai tidak efektif karena dapat mengakibatkan “kanibalisasi” antar brand, terlebih jika perhatian terhadap target konsumen diabaikan sebelum menyusun perencanaan IMC. Kata Kunci: Bisnis, Integrated Marketing Communications, Pemasaran

  8. Design alternatives for beam halo monitors in high intensity accelerators

    CERN Document Server

    Braun, H; Corsini, R; Lefèvre, T; Schulte, Daniel; Tecker, F A; Welsch, C P

    2005-01-01

    In future high intensity, high energy accelerators it must be ensured that particle losses are minimized as activation of the vacuum chambers or other components makes maintenance and upgrade work time consuming and costly. It is imperative to have a clear understanding of the mechanisms that can lead to halo formation and to have the possibility to test available theoretical models with an adequate experimental setup. Optical transition radiation (OTR) provides an interesting opportunity for linear real-time measurements of the transverse beam profile with a resolution which has been so far at best in the some μm range. However, the dynamic range of standard OTR systems is typically limited and needs to be improved for its application for halo measurements. In this contribution, the existing OTR system as it is installed in the CLIC test facility (CTF3) is analyzed and the contribution of each component to the final image quality discussed. Finally, possible halo measurement techniques based on OTR are pres...

  9. Detecting Hot Gaseous Halos of Galaxies with Arcus

    Science.gov (United States)

    Bregman, Joel N.; Hodges-Kluck, Edmund; Li, Jiangtao; Li, Yunyang; Miller, Matthew; Qu, Zhijie

    2018-01-01

    A long-lived component of galaxies is the hot extended atmosphere with a temperature near the virial temperature. It can contain a significant fraction of the missing baryons and can act as a reservoir of matter for future generations of stars. This extended hot halo is detected around the Milky Way in absorption and emission lines of highly ionized species (e.g., O VII, O VIII), but weighted to be within about 50 kpc. From current data there are not many high fidelity absorption line detections and the lines are badly under-resolved. These shortcomings will be rectified with Arcus, which will provide high-quality line measurements in several ions for about 50 sight lines. Lines will often be resolved, revealing the dynamics of the hot halo, such as rotation and the turbulence resulting from feedback. We show how metallicities will be determined from a comparison of these absorption lines with existing emission line data. Arcus will detect O VII absorption from similar halos around external galaxies, for the first time, and out to ~R200, if not beyond. Using random lines of sight, Arcus will complete the metal census of the Universe.

  10. Dwarf Galaxies in Voids: Dark Matter Halos and Gas Cooling

    Directory of Open Access Journals (Sweden)

    Matthias Hoeft

    2010-01-01

    Full Text Available Galaxy surveys have shown that luminous galaxies are mainly distributed in large filaments and galaxy clusters. The remaining large volumes are virtually devoid of luminous galaxies. This is in concordance with the formation of the large-scale structure in the universe as derived from cosmological simulations. However, the numerical results indicate that cosmological voids are abundantly populated with dark matter haloes which may in principle host dwarf galaxies. Observational efforts have in contrast revealed that voids are apparently devoid of dwarf galaxies. We investigate the formation of dwarf galaxies in voids by hydrodynamical cosmological simulations. Due to the cosmic ultraviolet background radiation low-mass haloes show generally a reduced baryon fraction. We determine the characteristic mass below which dwarf galaxies are baryon deficient. We show that the circular velocity below which the accretion of baryons is suppressed is approximately 40 kms−1. The suppressed baryon accretion is caused by the photo-heating due to the UV background. We set up a spherical halo model and show that the effective equation of the state of the gas in the periphery of dwarf galaxies determines the characteristic mass. This implies that any process which heats the gas around dwarf galaxies increases the characteristic mass and thus reduces the number of observable dwarf galaxies.

  11. Ultra-Deep Imaging: Structure of Disks and Haloes

    Science.gov (United States)

    Knapen, Johan H.; Trujillo, Ignacio

    Deep imaging is a fundamental tool in the study of the outermost structures of galaxies. We review recent developments in ultra-deep imaging of galaxy disks and haloes, highlighting the technical advances as well as the challenges and summarizing observational results in the context of modern theory and simulations. The deepest modern galaxy imaging comes from three main sources: (1) surveys such as the Sloan Digital Sky Survey's Stripe 82 project; (2) very long exposures on small telescopes, including by amateurs; and (3) long exposures on the largest professional telescopes. The technical challenges faced are common in all these approaches and include the treatment of light scattered by atmosphere and telescope/instrument, correct flat fielding and the subtraction of non-galaxy light in the images. We review scientific results on galaxy disks and haloes obtained with deep imaging, including the detection and characterization of stellar haloes, tidal features and stellar streams, disk truncations and thick disks. The area of ultra-deep imaging is still very much unexplored territory, and future work in this area promises significant advances in our understanding of galaxy formation and evolution.

  12. Shot noise and biased tracers: A new look at the halo model

    Science.gov (United States)

    Ginzburg, Dimitry; Desjacques, Vincent; Chan, Kwan Chuen

    2017-10-01

    Shot noise is an important ingredient to any measurement or theoretical modeling of discrete tracers of the large scale structure. Recent work has shown that the shot noise in the halo power spectrum becomes increasingly sub-Poissonian at high mass. Interestingly, while the halo model predicts a shot noise power spectrum in qualitative agreement with the data, it leads to an unphysical white noise in the cross halo-matter and matter power spectrum. In this work, we show that absorbing all the halo model sources of shot noise into the halo fluctuation field leads to meaningful predictions for the shot noise contributions to halo clustering statistics and remove the unphysical white noise from the cross halo-matter statistics. Our prescription straightforwardly maps onto the general bias expansion, so that the renormalized shot noise terms can be expressed as combinations of the halo model shot noises. Furthermore, we demonstrate that non-Poissonian contributions are related to volume integrals over correlation functions and their response to long-wavelength density perturbations. This leads to a new class of consistency relations for discrete tracers, which appear to be satisfied by our reformulation of the halo model. We test our theoretical predictions against measurements of halo shot noise bispectra extracted from a large suite of numerical simulations. Our model reproduces qualitatively the observed sub-Poissonian noise, although it underestimates the magnitude of this effect.

  13. An FPGA-Based Track Finder for the L1 Trigger of the CMS Experiment at the High Luminosity LHC

    CERN Document Server

    Aggleton, Robin Cameron; Ball, Fionn Amhairghen; Balzer, Matthias Norbert; Boudoul, Gaelle; Brooke, James John; Caselle, Michele; Calligaris, Luigi; Cieri, Davide; Clement, Emyr John; Dutta, Suchandra; Hall, Geoffrey; Harder, Kristian; Hobson, Peter; Iles, Gregory Michiel; James, Thomas Owen; Manolopoulos, Konstantinos; Matsushita, Takashi; Morton, Alexander; Newbold, David; Paramesvaran, Sudarshan; Pesaresi, Mark Franco; Pozzobon, Nicola; Reid, Ivan; Rose, A. W; Sander, Oliver; Shepherd-Themistocleous, Claire; Shtipliyski, Antoni; Schuh, Thomas; Skinnari, Louise; Summers, Sioni Paris; Tapper, Alexander; Tomalin, Ian; Thea, Alessandro; Uchida, Kirika; Vichoudis, Paschalis; Viret, Sebastien; Weber, M

    2017-01-01

    A concept for an FPGA-based track finder using a fully time-multiplexed architecture is presented, where track candidates are reconstructed using a projective binning algorithm based on the Hough Transform, followed by a combinatorial Kalman Filter. A hardware demonstrator using MP7 processing boards has been assembled to prove the entire system functionality, from the output of the tracker readout boards to the reconstruction of tracks with fitted helix parameters. It successfully operates on one eighth of the tracker solid angle acceptance at a time, processing events taken at 40 MHz, each with up to 200 superimposed proton-proton interactions, whilst satisfying the latency requirement...

  14. Range estimation techniques in single-station thunderstorm warning sensors based upon gated, wideband, magnetic direction finder technology

    Science.gov (United States)

    Pifer, Alburt E.; Hiscox, William L.; Cummins, Kenneth L.; Neumann, William T.

    1991-01-01

    Gated, wideband, magnetic direction finders (DFs) were originally designed to measure the bearing of cloud-to-ground lightning relative to the sensor. A recent addition to this device uses proprietary waveform discrimination logic to select return stroke signatures and certain range dependent features in the waveform to provide an estimate of range of flashes within 50 kms. The enhanced ranging techniques are discussed which were designed and developed for use in single station thunderstorm warning sensor. Included are the results of on-going evaluations being conducted under a variety of meteorological and geographic conditions.

  15. Emulation of a prototype FPGA track finder for the CMS Phase-2 upgrade with the CIDAF emulation framework.

    CERN Document Server

    Amstutz, Christian; Balzer, Matthias Norbert; Brooke, James John; Calligaris, Luigi; Cieri, Davide; Clement, Emyr John; Hall, Geoffrey; Harbaum, Tanja Renate; Harder, Kristian; Hobson, Peter; Iles, Gregory Michiel; James, Thomas Owen; Manolopoulos, Konstantinos; Matsushita, Takashi; Morton, Alexander; Newbold, David; Paramesvaran, Sudarshan; Pesaresi, Mark Franco; Reid, Ivan; Rose, A. W; Sander, Oliver; Schuh, Thomas; Shepherd-Themistocleous, Claire; Shtipliyski, Antoni; Summers, Sioni Paris; Tapper, Alexander; Tomalin, Ian; Uchida, Kirika; Vichoudis, Paschalis; Weber, M

    2016-01-01

    The CMS collaboration is preparing a major upgrade of its detector, so it can operate during the high luminosity run of the LHC from 2026. The upgraded tracker electronics will reconstruct the trajectories of charged particles within a latency of a few microseconds, so that they can be used by the level-1 trigger. An emulation framework, CIDAF, has been developed to provide a reference for a proposed FPGA-based implementation of this track finder, which employs a Time-Multiplexed (TM) technique for data processing.

  16. ARC Code TI: Block-GP: Scalable Gaussian Process Regression

    Data.gov (United States)

    National Aeronautics and Space Administration — Block GP is a Gaussian Process regression framework for multimodal data, that can be an order of magnitude more scalable than existing state-of-the-art nonlinear...

  17. Scalable pattern recognition algorithms applications in computational biology and bioinformatics

    CERN Document Server

    Maji, Pradipta

    2014-01-01

    Reviews the development of scalable pattern recognition algorithms for computational biology and bioinformatics Includes numerous examples and experimental results to support the theoretical concepts described Concludes each chapter with directions for future research and a comprehensive bibliography

  18. Scalability of telecom cloud architectures for live-TV distribution

    OpenAIRE

    Asensio Carmona, Adrian; Contreras, Luis Miguel; Ruiz Ramírez, Marc; López Álvarez, Victor; Velasco Esteban, Luis Domingo

    2015-01-01

    A hierarchical distributed telecom cloud architecture for live-TV distribution exploiting flexgrid networking and SBVTs is proposed. Its scalability is compared to that of a centralized architecture. Cost savings as high as 32 % are shown. Peer Reviewed

  19. Evaluating the Scalability of Enterprise JavaBeans Technology

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yan (Jenny); Gorton, Ian; Liu, Anna; Chen, Shiping; Paul A Strooper; Pornsiri Muenchaisri

    2002-12-04

    One of the major problems in building large-scale distributed systems is to anticipate the performance of the eventual solution before it has been built. This problem is especially germane to Internet-based e-business applications, where failure to provide high performance and scalability can lead to application and business failure. The fundamental software engineering problem is compounded by many factors, including individual application diversity, software architecture trade-offs, COTS component integration requirements, and differences in performance of various software and hardware infrastructures. In this paper, we describe the results of an empirical investigation into the scalability of a widely used distributed component technology, Enterprise JavaBeans (EJB). A benchmark application is developed and tested to measure the performance of a system as both the client load and component infrastructure are scaled up. A scalability metric from the literature is then applied to analyze the scalability of the EJB component infrastructure under two different architectural solutions.

  20. Scalable RFCMOS Model for 90 nm Technology

    Directory of Open Access Journals (Sweden)

    Ah Fatt Tong

    2011-01-01

    Full Text Available This paper presents the formation of the parasitic components that exist in the RF MOSFET structure during its high-frequency operation. The parasitic components are extracted from the transistor's S-parameter measurement, and its geometry dependence is studied with respect to its layout structure. Physical geometry equations are proposed to represent these parasitic components, and by implementing them into the RF model, a scalable RFCMOS model, that is, valid up to 49.85 GHz is demonstrated. A new verification technique is proposed to verify the quality of the developed scalable RFCMOS model. The proposed technique can shorten the verification time of the scalable RFCMOS model and ensure that the coded scalable model file is error-free and thus more reliable to use.

  1. Scalable-to-lossless transform domain distributed video coding

    DEFF Research Database (Denmark)

    Huang, Xin; Ukhanova, Ann; Veselov, Anton

    2010-01-01

    Distributed video coding (DVC) is a novel approach providing new features as low complexity encoding by mainly exploiting the source statistics at the decoder based on the availability of decoder side information. In this paper, scalable-tolossless DVC is presented based on extending a lossy...... TransformDomain Wyner-Ziv (TDWZ) distributed video codec with feedback.The lossless coding is obtained by using a reversible integer DCT.Experimental results show that the performance of the proposed scalable-to-lossless TDWZ video codec can outperform alternatives based on the JPEG 2000 standard. The TDWZ...... codec provides frame by frame encoding. Comparing the lossless coding efficiency, the proposed scalable-to-lossless TDWZ video codec can save up to 5%-13% bits compared to JPEG LS and H.264 Intra frame lossless coding and do so as a scalable-to-lossless coding....

  2. Improving the Performance Scalability of the Community Atmosphere Model

    Energy Technology Data Exchange (ETDEWEB)

    Mirin, Arthur [Lawrence Livermore National Laboratory (LLNL); Worley, Patrick H [ORNL

    2012-01-01

    The Community Atmosphere Model (CAM), which serves as the atmosphere component of the Community Climate System Model (CCSM), is the most computationally expensive CCSM component in typical configurations. On current and next-generation leadership class computing systems, the performance of CAM is tied to its parallel scalability. Improving performance scalability in CAM has been a challenge, due largely to algorithmic restrictions necessitated by the polar singularities in its latitude-longitude computational grid. Nevertheless, through a combination of exploiting additional parallelism, implementing improved communication protocols, and eliminating scalability bottlenecks, we have been able to more than double the maximum throughput rate of CAM on production platforms. We describe these improvements and present results on the Cray XT5 and IBM BG/P. The approaches taken are not specific to CAM and may inform similar scalability enhancement activities for other codes.

  3. Parallelism and Scalability in an Image Processing Application

    DEFF Research Database (Denmark)

    Rasmussen, Morten Sleth; Stuart, Matthias Bo; Karlsson, Sven

    2008-01-01

    parallel programs. This paper investigates parallelism and scalability of an embedded image processing application. The major challenges faced when parallelizing the application were to extract enough parallelism from the application and to reduce load imbalance. The application has limited immediately...

  4. Scalable Multiple-Description Image Coding Based on Embedded Quantization

    Directory of Open Access Journals (Sweden)

    Moerman Ingrid

    2007-01-01

    Full Text Available Scalable multiple-description (MD coding allows for fine-grain rate adaptation as well as robust coding of the input source. In this paper, we present a new approach for scalable MD coding of images, which couples the multiresolution nature of the wavelet transform with the robustness and scalability features provided by embedded multiple-description scalar quantization (EMDSQ. Two coding systems are proposed that rely on quadtree coding to compress the side descriptions produced by EMDSQ. The proposed systems are capable of dynamically adapting the bitrate to the available bandwidth while providing robustness to data losses. Experiments performed under different simulated network conditions demonstrate the effectiveness of the proposed scalable MD approach for image streaming over error-prone channels.

  5. Scalable Multiple-Description Image Coding Based on Embedded Quantization

    Directory of Open Access Journals (Sweden)

    Augustin I. Gavrilescu

    2007-02-01

    Full Text Available Scalable multiple-description (MD coding allows for fine-grain rate adaptation as well as robust coding of the input source. In this paper, we present a new approach for scalable MD coding of images, which couples the multiresolution nature of the wavelet transform with the robustness and scalability features provided by embedded multiple-description scalar quantization (EMDSQ. Two coding systems are proposed that rely on quadtree coding to compress the side descriptions produced by EMDSQ. The proposed systems are capable of dynamically adapting the bitrate to the available bandwidth while providing robustness to data losses. Experiments performed under different simulated network conditions demonstrate the effectiveness of the proposed scalable MD approach for image streaming over error-prone channels.

  6. Merger Histories of Galaxy Halos and Implications for Disk Survival

    Energy Technology Data Exchange (ETDEWEB)

    Stewart, Kyle R.; Bullock, James S.; Wechsler, Risa H.; Maller, Ariyeh H.; Zentner, Andrew R.

    2008-05-16

    The authors study the merger histories of galaxy dark matter halos using a high resolution {Lambda}CDM N-body simulation. The merger trees follow {approx} 17,000 halos with masses M{sub 0} = (10{sup 11} - 10{sup 13})h{sup -1}M{sub {circle_dot}} at z = 0 and track accretion events involving objects as small as m {approx_equal} 10{sup 10} h{sup -1}M{sub {circle_dot}}. They find that mass assembly is remarkably self-similar in m/M{sub 0}, and dominated by mergers that are {approx}10% of the final halo mass. While very large mergers, m {approx}> 0.4 M{sub 0}, are quite rare, sizeable accretion events, m {approx} 0.1 M{sub 0}, are common. Over the last {approx} 10 Gyr, an overwhelming majority ({approx} 95%) of Milky Way-sized halos with M{sub 0} = 10{sup 12} h{sup -1}M{sub {circle_dot}} have accreted at least one object with greater total mass than the Milky Way disk (m > 5 x 10{sup 10} h{sup -1}M{sub {circle_dot}}), and approximately 70% have accreted an object with more than twice that mass (m > 10{sup 11} h{sup -1}M{sub {circle_dot}}). The results raise serious concerns about the survival of thin-disk dominated galaxies within the current paradigm for galaxy formation in a {Lambda}CDM universe. in order to achieve a {approx} 70% disk-dominated fraction in Milky Way-sized {Lambda}CDM halos, mergers involving m {approx_equal} 2 x 10{sup 11} h{sup -1}M{sub {circle_dot}} objects must not destroy disks. Considering that most thick disks and bulges contain old stellar populations, the situation is even more restrictive: these mergers must not heat disks or drive gas into their centers to create young bulges.

  7. TriG: Next Generation Scalable Spaceborne GNSS Receiver

    Science.gov (United States)

    Tien, Jeffrey Y.; Okihiro, Brian Bachman; Esterhuizen, Stephan X.; Franklin, Garth W.; Meehan, Thomas K.; Munson, Timothy N.; Robison, David E.; Turbiner, Dmitry; Young, Lawrence E.

    2012-01-01

    TriG is the next generation NASA scalable space GNSS Science Receiver. It will track all GNSS and additional signals (i.e. GPS, GLONASS, Galileo, Compass and Doris). Scalable 3U architecture and fully software and firmware recofigurable, enabling optimization to meet specific mission requirements. TriG GNSS EM is currently undergoing testing and is expected to complete full performance testing later this year.

  8. SDC: Scalable description coding for adaptive streaming media

    OpenAIRE

    Quinlan, Jason J.; Zahran, Ahmed H.; Sreenan, Cormac J.

    2012-01-01

    Video compression techniques enable adaptive media streaming over heterogeneous links to end-devices. Scalable Video Coding (SVC) and Multiple Description Coding (MDC) represent well-known techniques for video compression with distinct characteristics in terms of bandwidth efficiency and resiliency to packet loss. In this paper, we present Scalable Description Coding (SDC), a technique to compromise the tradeoff between bandwidth efficiency and error resiliency without sacrificing user-percei...

  9. Galaxy power spectrum in redshift space: Combining perturbation theory with the halo model

    Science.gov (United States)

    Okumura, Teppei; Hand, Nick; Seljak, Uroš; Vlah, Zvonimir; Desjacques, Vincent

    2015-11-01

    Theoretical modeling of the redshift-space power spectrum of galaxies is crucially important to correctly extract cosmological information from galaxy redshift surveys. The task is complicated by the nonlinear biasing and redshift space distortion (RSD) effects, which change with halo mass, and by the wide distribution of halo masses and their occupations by galaxies. One of the main modeling challenges is the existence of satellite galaxies that have both radial distribution inside the halos and large virial velocities inside halos, a phenomenon known as the Finger-of-God (FoG) effect. We present a model for the redshift-space power spectrum of galaxies in which we decompose a given galaxy sample into central and satellite galaxies and relate different contributions to the power spectrum to 1-halo and 2-halo terms in a halo model. Our primary goal is to ensure that any parameters that we introduce have physically meaningful values, and are not just fitting parameters. For the lowest order 2-halo terms we use the previously developed RSD modeling of halos in the context of distribution function and perturbation theory approach. This term needs to be multiplied by the effect of radial distances and velocities of satellites inside the halo. To this one needs to add the 1-halo terms, which are nonperturbative. We show that the real space 1-halo terms can be modeled as almost constant, with the finite extent of the satellites inside the halo inducing a small k2R2 term over the range of scales of interest, where R is related to the size of the halo given by its halo mass. We adopt a similar model for FoG in redshift space, ensuring that FoG velocity dispersion is related to the halo mass. For FoG k2 type expansions do not work over the range of scales of interest and FoG resummation must be used instead. We test several simple damping functions to model the velocity dispersion FoG effect. Applying the formalism to mock galaxies modeled after the "CMASS" sample of the

  10. Event and Apparent Horizon Finders for 3+1 Numerical Relativity

    Directory of Open Access Journals (Sweden)

    Thornburg Jonathan

    2007-06-01

    Full Text Available Event and apparent horizons are key diagnostics for the presence and properties of black holes. In this article I review numerical algorithms and codes for finding event and apparent horizons in numerically-computed spacetimes, focusing on calculations done using the 3+1 ADM formalism. The event horizon of an asymptotically-flat spacetime is the boundary between those events from which a future-pointing null geodesic can reach future null infinity and those events from which no such geodesic exists. The event horizon is a (continuous null surface in spacetime. The event horizon is defined nonlocally in time: it is a global property of the entire spacetime and must be found in a separate post-processing phase after all (or at least the nonstationary part of spacetime has been numerically computed.There are three basic algorithms for finding event horizons, based on integrating null geodesics forwards in time, integrating null geodesics backwards in time, and integrating null surfaces backwards in time. The last of these is generally the most efficient and accurate.In contrast to an event horizon, an apparent horizon is defined locally in time in a spacelike slice and depends only on data in that slice, so it can be (and usually is found during the numerical computation of a spacetime. A marginally outer trapped surface (MOTS in a slice is a smooth closed 2-surface whose future-pointing outgoing null geodesics have zero expansion Theta. An apparent horizon is then defined as a MOTS not contained in any other MOTS. The MOTS condition is a nonlinear elliptic partial differential equation (PDE for the surface shape, containing the ADM 3-metric, its spatial derivatives, and the extrinsic curvature as coefficients. Most “apparent horizon” finders actually find MOTSs.There are a large number of apparent horizon finding algorithms, with differing trade-offs between speed, robustness, accuracy, and ease of programming. In axisymmetry, shooting

  11. Autonomous Observing and Planet Discovery with the Automated Planet Finder (APF)

    Science.gov (United States)

    Burt, Jennifer; Hanson, Russell; Holden, Bradford; Butler, R. Paul; Vogt, Steven S.; Laughlin, Greg

    2015-01-01

    The Automated Planet Finder (APF) is a dedicated, ground-based precision radial velocity facility located at Lick Observatory, operated by University of California Observatories (UCO). The 2.4-m telescope and accompanying high-resolution echelle spectrograph were specifically designed for the purpose of detecting planets in the habitable zone of low-mass stars. The telescope is operated every night (weather permitting) to achieve meaningful signal-to-noise gains from high cadence observing and to avoid the aliasing problems inherent to planets whose periods are close to the lunar month.The APF has been taking science quality data for over a year and has contributed to two planet discovery papers with data at a 1 m/s level of precision. The detection of these planets, especially the Uranus mass planet around GL687, indicates that the APF telescope is well suited to the discovery of low-mass planets orbiting low-mass stars in the as-yet relatively un-surveyed region of the sky near the north celestial pole.To take full advantage of the consistent influx of data it is necessary to analyze each night's results before deciding the next evening's targets. We are in the process of developing a fully automated reduction pipeline that will take data from raw FITS files to final radial velocity values and integrate those values into a master database. The database is then run through the publicly available Systemic console, a publically available software package for the analysis and combined multiparameter fitting of Doppler radial velocity observations. Systemic will re-calculate the possibility of planetary signals in the data and use this value, along with other considerations such as the star's brightness and chromospheric activity level, to assign it a priority rating for future observations.When the telescope is again on sky it uses a suite of stellar and atmospheric calibrations derived from the part year's observations to calculate the expected exposure time for

  12. The QuakeFinder Magnetometer Network - a Platform for Earth and Space Science Research

    Science.gov (United States)

    Bleier, T.; Kappler, K. N.; Schneider, D.

    2016-12-01

    QuakeFinder (QF) is a humanitarian research and development project attempting to characterize earth-emitting electromagnetic (EM) signals as potential precursors to earthquakes. Beginning in 2005, QF designed, built, deployed and now maintains an array of 165 remote monitoring stations in 6 countries (US/California, Taiwan, Greece, Indonesia, Peru and Chile). Having amassed approximately 70 TB of data and greater than 140 earthquakes (M4+), QF is focused on the data analysis and signal processing algorithms in our effort to enable a forecasting capability. QF's autonomous stations, located along major fault lines, collect and transmit electromagnetic readings from 3-axis induction magnetometers and positive/negative ion sensors, a geophone, as well as various station health status and local conditions. The induction magnetometers, oriented N-S,E-W and vertically, have a 40 nT range and 1 pT sensitivity. Data is continuously collected at 50 samples/sec (sps), GPS time-stamped and transmitted, primarily through cell phone networks, to our data center in Palo Alto, California. The induction magnetometers routinely detect subtle geomagnetic and ionospheric disturbances as observed worldwide. QF seeks to make available both historic data and the array platform to strategic partners in the EM-related research and operation fields. The QF system will be described in detail with examples of local and regional geomagnetic activity. The stations are robust and will be undergoing a system-level upgrade in the near future. Domestically, QF maintains a 98% `up time' among the 120 stations in California while internationally our metric is typically near 80%. Irregular cell phone reception is chief among the reasons for outages although little data has been lost as the stations can store up to 90 days of data. These data are retrieved by QF personnel or, when communication is reestablished, the QF data ingest process automatically updates the database. Planned station upgrades

  13. Scalable persistent identifier systems for dynamic datasets

    Science.gov (United States)

    Golodoniuc, P.; Cox, S. J. D.; Klump, J. F.

    2016-12-01

    Reliable and persistent identification of objects, whether tangible or not, is essential in information management. Many Internet-based systems have been developed to identify digital data objects, e.g., PURL, LSID, Handle, ARK. These were largely designed for identification of static digital objects. The amount of data made available online has grown exponentially over the last two decades and fine-grained identification of dynamically generated data objects within large datasets using conventional systems (e.g., PURL) has become impractical. We have compared capabilities of various technological solutions to enable resolvability of data objects in dynamic datasets, and developed a dataset-centric approach to resolution of identifiers. This is particularly important in Semantic Linked Data environments where dynamic frequently changing data is delivered live via web services, so registration of individual data objects to obtain identifiers is impractical. We use identifier patterns and pattern hierarchies for identification of data objects, which allows relationships between identifiers to be expressed, and also provides means for resolving a single identifier into multiple forms (i.e. views or representations of an object). The latter can be implemented through (a) HTTP content negotiation, or (b) use of URI querystring parameters. The pattern and hierarchy approach has been implemented in the Linked Data API supporting the United Nations Spatial Data Infrastructure (UNSDI) initiative and later in the implementation of geoscientific data delivery for the Capricorn Distal Footprints project using International Geo Sample Numbers (IGSN). This enables flexible resolution of multi-view persistent identifiers and provides a scalable solution for large heterogeneous datasets.

  14. Microscopic Characterization of Scalable Coherent Rydberg Superatoms

    Directory of Open Access Journals (Sweden)

    Johannes Zeiher

    2015-08-01

    Full Text Available Strong interactions can amplify quantum effects such that they become important on macroscopic scales. Controlling these coherently on a single-particle level is essential for the tailored preparation of strongly correlated quantum systems and opens up new prospects for quantum technologies. Rydberg atoms offer such strong interactions, which lead to extreme nonlinearities in laser-coupled atomic ensembles. As a result, multiple excitation of a micrometer-sized cloud can be blocked while the light-matter coupling becomes collectively enhanced. The resulting two-level system, often called a “superatom,” is a valuable resource for quantum information, providing a collective qubit. Here, we report on the preparation of 2 orders of magnitude scalable superatoms utilizing the large interaction strength provided by Rydberg atoms combined with precise control of an ensemble of ultracold atoms in an optical lattice. The latter is achieved with sub-shot-noise precision by local manipulation of a two-dimensional Mott insulator. We microscopically confirm the superatom picture by in situ detection of the Rydberg excitations and observe the characteristic square-root scaling of the optical coupling with the number of atoms. Enabled by the full control over the atomic sample, including the motional degrees of freedom, we infer the overlap of the produced many-body state with a W state from the observed Rabi oscillations and deduce the presence of entanglement. Finally, we investigate the breakdown of the superatom picture when two Rydberg excitations are present in the system, which leads to dephasing and a loss of coherence.

  15. Microscopic Characterization of Scalable Coherent Rydberg Superatoms

    Science.gov (United States)

    Zeiher, Johannes; Schauß, Peter; Hild, Sebastian; Macrı, Tommaso; Bloch, Immanuel; Gross, Christian

    2015-07-01

    Strong interactions can amplify quantum effects such that they become important on macroscopic scales. Controlling these coherently on a single-particle level is essential for the tailored preparation of strongly correlated quantum systems and opens up new prospects for quantum technologies. Rydberg atoms offer such strong interactions, which lead to extreme nonlinearities in laser-coupled atomic ensembles. As a result, multiple excitation of a micrometer-sized cloud can be blocked while the light-matter coupling becomes collectively enhanced. The resulting two-level system, often called a "superatom," is a valuable resource for quantum information, providing a collective qubit. Here, we report on the preparation of 2 orders of magnitude scalable superatoms utilizing the large interaction strength provided by Rydberg atoms combined with precise control of an ensemble of ultracold atoms in an optical lattice. The latter is achieved with sub-shot-noise precision by local manipulation of a two-dimensional Mott insulator. We microscopically confirm the superatom picture by in situ detection of the Rydberg excitations and observe the characteristic square-root scaling of the optical coupling with the number of atoms. Enabled by the full control over the atomic sample, including the motional degrees of freedom, we infer the overlap of the produced many-body state with a W state from the observed Rabi oscillations and deduce the presence of entanglement. Finally, we investigate the breakdown of the superatom picture when two Rydberg excitations are present in the system, which leads to dephasing and a loss of coherence.

  16. Myria: Scalable Analytics as a Service

    Science.gov (United States)

    Howe, B.; Halperin, D.; Whitaker, A.

    2014-12-01

    At the UW eScience Institute, we're working to empower non-experts, especially in the sciences, to write and use data-parallel algorithms. To this end, we are building Myria, a web-based platform for scalable analytics and data-parallel programming. Myria's internal model of computation is the relational algebra extended with iteration, such that every program is inherently data-parallel, just as every query in a database is inherently data-parallel. But unlike databases, iteration is a first class concept, allowing us to express machine learning tasks, graph traversal tasks, and more. Programs can be expressed in a number of languages and can be executed on a number of execution environments, but we emphasize a particular language called MyriaL that supports both imperative and declarative styles and a particular execution engine called MyriaX that uses an in-memory column-oriented representation and asynchronous iteration. We deliver Myria over the web as a service, providing an editor, performance analysis tools, and catalog browsing features in a single environment. We find that this web-based "delivery vector" is critical in reaching non-experts: they are insulated from irrelevant effort technical work associated with installation, configuration, and resource management. The MyriaX backend, one of several execution runtimes we support, is a main-memory, column-oriented, RDBMS-on-the-worker system that supports cyclic data flows as a first-class citizen and has been shown to outperform competitive systems on 100-machine cluster sizes. I will describe the Myria system, give a demo, and present some new results in large-scale oceanographic microbiology.

  17. Physical principles for scalable neural recording.

    Science.gov (United States)

    Marblestone, Adam H; Zamft, Bradley M; Maguire, Yael G; Shapiro, Mikhail G; Cybulski, Thaddeus R; Glaser, Joshua I; Amodei, Dario; Stranges, P Benjamin; Kalhor, Reza; Dalrymple, David A; Seo, Dongjin; Alon, Elad; Maharbiz, Michel M; Carmena, Jose M; Rabaey, Jan M; Boyden, Edward S; Church, George M; Kording, Konrad P

    2013-01-01

    Simultaneously measuring the activities of all neurons in a mammalian brain at millisecond resolution is a challenge beyond the limits of existing techniques in neuroscience. Entirely new approaches may be required, motivating an analysis of the fundamental physical constraints on the problem. We outline the physical principles governing brain activity mapping using optical, electrical, magnetic resonance, and molecular modalities of neural recording. Focusing on the mouse brain, we analyze the scalability of each method, concentrating on the limitations imposed by spatiotemporal resolution, energy dissipation, and volume displacement. Based on this analysis, all existing approaches require orders of magnitude improvement in key parameters. Electrical recording is limited by the low multiplexing capacity of electrodes and their lack of intrinsic spatial resolution, optical methods are constrained by the scattering of visible light in brain tissue, magnetic resonance is hindered by the diffusion and relaxation timescales of water protons, and the implementation of molecular recording is complicated by the stochastic kinetics of enzymes. Understanding the physical limits of brain activity mapping may provide insight into opportunities for novel solutions. For example, unconventional methods for delivering electrodes may enable unprecedented numbers of recording sites, embedded optical devices could allow optical detectors to be placed within a few scattering lengths of the measured neurons, and new classes of molecularly engineered sensors might obviate cumbersome hardware architectures. We also study the physics of powering and communicating with microscale devices embedded in brain tissue and find that, while radio-frequency electromagnetic data transmission suffers from a severe power-bandwidth tradeoff, communication via infrared light or ultrasound may allow high data rates due to the possibility of spatial multiplexing. The use of embedded local recording and

  18. Memory-Scalable GPU Spatial Hierarchy Construction.

    Science.gov (United States)

    Qiming Hou; Xin Sun; Kun Zhou; Lauterbach, C; Manocha, D

    2011-04-01

    Recent GPU algorithms for constructing spatial hierarchies have achieved promising performance for moderately complex models by using the breadth-first search (BFS) construction order. While being able to exploit the massive parallelism on the GPU, the BFS order also consumes excessive GPU memory, which becomes a serious issue for interactive applications involving very complex models with more than a few million triangles. In this paper, we propose to use the partial breadth-first search (PBFS) construction order to control memory consumption while maximizing performance. We apply the PBFS order to two hierarchy construction algorithms. The first algorithm is for kd-trees that automatically balances between the level of parallelism and intermediate memory usage. With PBFS, peak memory consumption during construction can be efficiently controlled without costly CPU-GPU data transfer. We also develop memory allocation strategies to effectively limit memory fragmentation. The resulting algorithm scales well with GPU memory and constructs kd-trees of models with millions of triangles at interactive rates on GPUs with 1 GB memory. Compared with existing algorithms, our algorithm is an order of magnitude more scalable for a given GPU memory bound. The second algorithm is for out-of-core bounding volume hierarchy (BVH) construction for very large scenes based on the PBFS construction order. At each iteration, all constructed nodes are dumped to the CPU memory, and the GPU memory is freed for the next iteration's use. In this way, the algorithm is able to build trees that are too large to be stored in the GPU memory. Experiments show that our algorithm can construct BVHs for scenes with up to 20 M triangles, several times larger than previous GPU algorithms.

  19. Injection halos of hydrocarbons above oil-gas fields with super-high pressures

    Energy Technology Data Exchange (ETDEWEB)

    Bakhtin, V.V.

    1979-09-01

    We studied the origin of injection halos of hydrocarbons above oil-gas fields with anomalously high formation pressures (AHFP). Using fields in Azerbaydzhan and Chechen-Ingushetiya as an example, we demonstrate the effect of certain factors (in particular, faults and zones of increased macro- and micro-jointing) on the morpholoy of the halos. The intensity of micro-jointing (jointing permeability, three-dimensional density of micro-jointing) is directly connected with vertical dimensions of the halos. We measured halos based on transverse profiles across the Khayan-Kort field and studied the distribution of bitumen saturation within the injection halo. Discovery of injection halos during drilling has enabled us to improve the technology of wiring deep-seated exploratory wells for oil and gas in regions with development of AHFP.

  20. Hydrocarbon halo distribution above oil and gas deposits with abnormally high stratal pressures

    Energy Technology Data Exchange (ETDEWEB)

    Bakhtin, V.V.

    1978-01-01

    An examination is made of the emergence of hydrocarbon halos over oil and gas deposits with abnormally high stratal pressure. Fields in Azerbaidzhan and Checheno-Ingushetiya are used to illustrate the effect of certain factors (particularly fractures, zones with heightened macro and microfissure formation) on halo morphology. A direct relationship was found between the intensity of microfissure formation (fissure permeability, volumetric density of microfissures) and the size of vertically directed halos. Dimensions are given for halos by cross-sectional profiles of the Khayan-Kort field, and information is given on the nature of bitumen saturation distribution within the halo. The identification of halos in the process of drilling will make it possible to improve the technology of cutting deep gas and oil exploratory wells in the regions of abnormally high stratal pressures are developing. 22 references, 4 figures, 1 table.

  1. Group support system and explanatory feedback: An experimental study of mitigating halo effect

    Directory of Open Access Journals (Sweden)

    Intiyas Utami

    2015-12-01

    Full Text Available Comprehensive assessment potentially leads to halo effect that will affect accuracy of auditors decision-making process. Biased initial audit decision will potentially influence final audit decision. It is there-fore necessary to mitigate halo effect that is the consequence of auditors good impression on clients initial condition. This re-search aims to empirically show that halo effect can be mitigated by explanatory feedback and Group Support System (GSS. The researchers experimentally mani-pulate explanatory feedback and GSS using online web-site. The subjects are stu-dents who have already taken auditing courses. The results show that: 1 explanato-ry feedback can mitigate halo effect so that audit decision will be more accurate 2 GSS can also mitigate halo effect 3 explanatory feedback and GSS are the best me-thods to mitigate halo effect.

  2. HaloTag as a reporter gene: positron emission tomography imaging with 64Cu-labeled second generation HaloTag ligands

    Science.gov (United States)

    Hong, Hao; Benink, Hélène A; Uyeda, H Tetsuo; Valdovinos, Hector F; Zhang, Yin; Meisenheimer, Poncho; Barnhart, Todd E; Fan, Frank; Cai, Weibo

    2013-01-01

    The goal of this study is to employ the HaloTag technology for positron emission tomography (PET), which involves two components: the HaloTag protein (a modified hydrolase which covalently binds to synthetic ligands) and HaloTag ligands (HTLs). 4T1 murine breast cancer cells were stably transfected to express HaloTag protein on the surface (termed as 4T1-HaloTag-ECS, ECS denotes extracellular surface). Two new HTLs were synthesized and termed NOTA-HTL2G-S and NOTA-HTL2G-L (2G indicates second generation, S stands for short, L stands for long, NOTA denotes 1,4,7-triazacyclononane-N,N’N’’-triacetic acid). Microscopy studies confirmed surface expression of HaloTag in 4T1-HaloTag-ECS cells, which specifically bind NOTA-HTL2G-S/L. Uptake of 64Cu-NOTA-HTL2G-L in 4T1-HaloTag-ECS tumors (4.3 ± 0.5, 4.1± 0.2, 4.0 ± 0.2, 2.3 ± 0.1, and 2.2 ± 0.1 %ID/g at 0.5, 3, 6, 18, and 24 h post-injection respectively; n = 4) was significantly higher than that in the 4T1 tumors (3.0 ± 0.3, 3.0± 0.1, 3.0 ± 0.2, 2.0 ± 0.4, and 2.4 ± 0.3 %ID/g at 0.5, 3, 6, 18, and 24 h post-injection respectively; n = 4) at early time points. In comparison, 64Cu-NOTA-HTL2G-S did not demonstrate significant uptake in either 4T1-HaloTag-ECS or 4T1 tumors. Blocking studies and autoradiography of tumor lysates confirmed that 64Cu-NOTA-HTL2G-L binds specifically to HaloTag protein in the 4T1-HaloTag-ECS tumors, corroborated by histology. HaloTag protein-specific targeting and PET imaging in vivo with 64Cu-NOTA-HTL2G-L serves as a proof-of-principle for future non-invasive and sensitive tracking of HaloTag-transfected cells with PET, as well as many other studies of gene/protein/cell function in vivo. PMID:23634240

  3. The Impact of Assembly Bias on the Galaxy Content of Dark Matter Halos

    Science.gov (United States)

    Zehavi, Idit; Contreras, Sergio; Padilla, Nelson; Smith, Nicholas J.; Baugh, Carlton M.; Norberg, Peder

    2018-01-01

    We study the dependence of the galaxy content of dark matter halos on large-scale environment and halo formation time using semi-analytic galaxy models applied to the Millennium simulation. We analyze subsamples of halos at the extremes of these distributions and measure the occupation functions for the galaxies they host. We find distinct differences among these occupation functions. The main effect with environment is that central galaxies (and in one model, also the satellites) in denser regions start populating lower-mass halos. A similar, but significantly stronger, trend exists with halo age, where early-forming halos are more likely to host central galaxies at lower halo mass. We discuss the origin of these trends and the connection to the stellar mass–halo mass relation. We find that, at fixed halo mass, older halos and to some extent also halos in dense environments tend to host more massive galaxies. Additionally, we see a reverse trend for the occupation of satellite galaxies where early-forming halos have fewer satellites, likely due to having more time for them to merge with the central galaxy. We describe these occupancy variations in terms of the changes in the occupation function parameters, which can aid in constructing realistic mock galaxy samples. Finally, we study the corresponding galaxy auto- and cross-correlation functions of the different samples and elucidate the impact of assembly bias on galaxy clustering. Our results can inform theoretical modeling of galaxy assembly bias and attempts to detect it in the real universe.

  4. Pressure at the ISM-halo interface: A reheating frequency dependence

    Directory of Open Access Journals (Sweden)

    Ćirković M.M.

    1998-01-01

    Full Text Available The dependence of the thermal pressure of hot galactic halos on a model parameter describing the frequency of major reheating episodes during galactic history is investigated. Pressure on the interface between interstellar medium and the halo gas is especially interesting, since empirical evidence here offers one of the simplest constraints on halo models. It is shown that two-phase model of Mo & Miralda-Escudé is sufficiently robust with respect to uncertainties in the average interval between reheating.

  5. HaloTag-based purification of functional human kinases from mammalian cells.

    Science.gov (United States)

    Ohana, Rachel Friedman; Hurst, Robin; Vidugiriene, Jolanta; Slater, Michael R; Wood, Keith V; Urh, Marjeta

    2011-04-01

    Although cultured mammalian cells are preferred for producing functional mammalian proteins with appropriate post-translational modifications, purification of recombinant proteins is frequently hampered by low expression. We have addressed this by creating a new method configured specifically for mammalian cell culture that provides rapid detection and efficient purification. This approach is based on HaloTag, a protein fusion tag designed to bind rapidly, selectively and covalently to a series of synthetic ligands that can carry a variety of functional groups, including fluorescent dyes for detection or solid supports for purification. Since the binding of HaloTag to the HaloLink resin is essentially irreversible, it overcomes the equilibrium-based binding limitations associated with affinity tags and enables efficient capture and purification of target protein, even at low expression levels. The target protein is released from the HaloLink resin by specific cleavage using a TEV protease fused to HaloTag (HaloTEV), leaving both HaloTag and HaloTEV permanently attached to the resin and highly pure, tag-free protein in solution. HaloTag fluorescent ligands enable fluorescent labeling of HaloTag fusion proteins, providing a convenient way to monitor expression, and thus facilitate the identification of optimal transient transfection conditions as well as the selection of high expression stable cell lines. The capabilities of this method have been demonstrated by the efficient purification of five functional human kinases from HEK293T cells. In addition, when purifications using FLAG, 3xFLAG, His(6)Tag and HaloTag were performed in parallel, HaloTag was shown to provide significantly higher yields, purity and overall recovery of the expressed proteins. Copyright © 2010 Elsevier Inc. All rights reserved.

  6. HaloTag: a novel reporter gene for positron emission tomography.

    Science.gov (United States)

    Hong, Hao; Benink, Hélène A; Zhang, Yin; Yang, Yunan; Uyeda, H Tetsuo; Engle, Jonathan W; Severin, Gregory W; McDougall, Mark G; Barnhart, Todd E; Klaubert, Dieter H; Nickles, Robert J; Fan, Frank; Cai, Weibo

    2011-08-15

    Among the many molecular imaging techniques, reporter gene imaging has been a dynamic area of research. The HaloTag protein is a modified haloalkane dehalogenase which was designed to covalently bind to synthetic ligands (i.e. the HaloTag ligands [HTL]). Covalent bond formation between the HaloTag protein and the chloroal-kane within the HTL occurs rapidly under physiological conditions, which is highly specific and essentially irreversible. Over the years, HaloTag technology has been investigated for various applications such as in vitro/in vivo imaging, protein purification/trafficking, high-throughput assays, among others. The goal of this study is to explore the use of the HaloTag protein as a novel reporter gene for positron emission tomography (PET) imaging. By attaching a HaloTag -reactive chloroalkane to 1, 4, 7-triazacyclononane-N, N', N"-triacetic acid (NOTA) through hydrophilic linkers, the resulting NOTA-conjugated HTLs were labeled with (64)Cu and tested for PET imaging in living mice bearing 4T1-HaloTag-ECS tumors, which stably express the HaloTag protein on the cell surface. Significantly higher uptake of (64)Cu-NOTA-HTL-S (which contains a short hydrophilic linker) in the 4T1-HaloTag-ECS than the non-HaloTag-expressing 4T1 tumors was observed, which demonstrated the HaloTag specificity of (64)Cu-NOTA-HTL-S and warranted future investigation of the HaloTag protein as a PET reporter gene.

  7. HaloTag Protein-Mediated Specific Labeling of Living Cells with Quantum Dots

    OpenAIRE

    So, Min-kyung; Yao, Hequan; Rao, Jianghong

    2008-01-01

    Quantum dots emerge as an attractive alternative to small molecule fluorophores as fluorescent tags for in vivo cell labeling and imaging. This communication presents a method for specific labeling of live cells using quantum dots. The labeling is mediated by HaloTag protein expressed at the cell surface which forms a stable covalent adduct with its ligand (HaloTag ligand). The labeling can be performed in one single step with quantum dot conjugates that are functionalized with HaloTag ligand...

  8. ZOMG - I. How the cosmic web inhibits halo growth and generates assembly bias

    Science.gov (United States)

    Borzyszkowski, Mikolaj; Porciani, Cristiano; Romano-Díaz, Emilio; Garaldi, Enrico

    2017-07-01

    The clustering of dark matter haloes with fixed mass depends on their formation history, an effect known as assembly bias. We use zoom N-body simulations to investigate the origin of this phenomenon. For each halo at redshift z = 0, we determine the time in which the physical volume containing its final mass becomes stable. We consider five examples for which this happens at z ˜ 1.5 and two that do not stabilize by z = 0. The zoom simulations show that early-collapsing haloes do not grow in mass at z = 0 while late-forming ones show a net inflow. The reason is that 'accreting' haloes are located at the nodes of a network of thin filaments feeding them. Conversely, each 'stalled' halo lies within a prominent filament that is thicker than the halo size. Infalling material from the surroundings becomes part of the filament while matter within it recedes from the halo. We conclude that assembly bias originates from quenching halo growth due to tidal forces following the formation of non-linear structures in the cosmic web, as previously conjectured in the literature. Also the internal dynamics of the haloes change: the velocity anisotropy profile is biased towards radial (tangential) orbits in accreting (stalled) haloes. Our findings reveal the cause of the yet unexplained dependence of halo clustering on the anisotropy. Finally, we extend the excursion-set theory to account for these effects. A simple criterion based on the ellipticity of the linear tidal field combined with the spherical-collapse model provides excellent predictions for both classes of haloes.

  9. PubDNA Finder: a web database linking full-text articles to sequences of nucleic acids.

    Science.gov (United States)

    García-Remesal, Miguel; Cuevas, Alejandro; Pérez-Rey, David; Martín, Luis; Anguita, Alberto; de la Iglesia, Diana; de la Calle, Guillermo; Crespo, José; Maojo, Víctor

    2010-11-01

    PubDNA Finder is an online repository that we have created to link PubMed Central manuscripts to the sequences of nucleic acids appearing in them. It extends the search capabilities provided by PubMed Central by enabling researchers to perform advanced searches involving sequences of nucleic acids. This includes, among other features (i) searching for papers mentioning one or more specific sequences of nucleic acids and (ii) retrieving the genetic sequences appearing in different articles. These additional query capabilities are provided by a searchable index that we created by using the full text of the 176 672 papers available at PubMed Central at the time of writing and the sequences of nucleic acids appearing in them. To automatically extract the genetic sequences occurring in each paper, we used an original method we have developed. The database is updated monthly by automatically connecting to the PubMed Central FTP site to retrieve and index new manuscripts. Users can query the database via the web interface provided. PubDNA Finder can be freely accessed at http://servet.dia.fi.upm.es:8080/pubdnafinder

  10. High-resolution disruption halo current measurements using Langmuir probes in Alcator C-Mod

    Science.gov (United States)

    Tinguely, R. A.; Granetz, R. S.; Berg, A.; Kuang, A. Q.; Brunner, D.; LaBombard, B.

    2018-01-01

    Halo currents generated during disruptions on Alcator C-Mod have been measured with Langmuir ‘rail’ probes. These rail probes are embedded in a lower outboard divertor module in a closely-spaced vertical (poloidal) array. The dense array provides detailed resolution of the spatial dependence (~1 cm spacing) of the halo current distribution in the plasma scrape-off region with high time resolution (400 kHz digitization rate). As the plasma limits on the outboard divertor plate, the contact point is clearly discernible in the halo current data (as an inversion of current) and moves vertically down the divertor plate on many disruptions. These data are consistent with filament reconstructions of the plasma boundary, from which the edge safety factor of the disrupting plasma can be calculated. Additionally, the halo current ‘footprint’ on the divertor plate is obtained and related to the halo flux width. The voltage driving halo current and the effective resistance of the plasma region through which the halo current flows to reach the probes are also investigated. Estimations of the sheath resistance and halo region resistivity and temperature are given. This information could prove useful for modeling halo current dynamics.

  11. Estimating the geoeffectiveness of halo CMEs from associated solar and IP parameters using neural networks

    Directory of Open Access Journals (Sweden)

    J. Uwamahoro

    2012-06-01

    Full Text Available Estimating the geoeffectiveness of solar events is of significant importance for space weather modelling and prediction. This paper describes the development of a neural network-based model for estimating the probability occurrence of geomagnetic storms following halo coronal mass ejection (CME and related interplanetary (IP events. This model incorporates both solar and IP variable inputs that characterize geoeffective halo CMEs. Solar inputs include numeric values of the halo CME angular width (AW, the CME speed (Vcme, and the comprehensive flare index (cfi, which represents the flaring activity associated with halo CMEs. IP parameters used as inputs are the numeric peak values of the solar wind speed (Vsw and the southward Z-component of the interplanetary magnetic field (IMF or Bs. IP inputs were considered within a 5-day time window after a halo CME eruption. The neural network (NN model training and testing data sets were constructed based on 1202 halo CMEs (both full and partial halo and their properties observed between 1997 and 2006. The performance of the developed NN model was tested using a validation data set (not part of the training data set covering the years 2000 and 2005. Under the condition of halo CME occurrence, this model could capture 100% of the subsequent intense geomagnetic storms (Dst ≤ −100 nT. For moderate storms (−100 < Dst ≤ −50, the model is successful up to 75%. This model's estimate of the storm occurrence rate from halo CMEs is estimated at a probability of 86%.

  12. HaloTag: a new versatile reporter gene system in plant cells.

    Science.gov (United States)

    Lang, Christina; Schulze, Jutta; Mendel, Ralf-R; Hänsch, Robert

    2006-01-01

    HaloTag Interchangeable Labeling Technology (HaloTag) was originally developed for mammalian cell analysis. In this report, the use of HaloTag is demonstrated in plant cells for the first time. This system allows different fluorescent colours to be used to visualize the localization of the non-fluorescent HaloTag protein within living cells. A vector was constructed which expresses the HaloTag protein under the control of the 35S promoter of cauliflower mosaic virus. The functionality of the HaloTag construct was tested in transient assays by (i) transforming tobacco protoplasts and (ii) using biolistic transformation of intact leaf cells of tobacco and poplar plants. Two to fourteen days after transformation, the plant material was incubated with ligands specific for labelling the HaloTag protein, and fluorescence was visualized by confocal laser scanning microscopy. The results demonstrate that HaloTag technology is a flexible system which generates efficient fluorescence in different types of plant cells. The ligand-specific labelling of HaloTag protein was not hampered by the plant cell wall.

  13. Discovering Protein Interactions and Characterizing Protein Function Using HaloTag Technology

    National Research Council Canada - National Science Library

    Daniels, Danette L; Méndez, Jacqui; Benink, Hélène; Niles, Andrew; Murphy, Nancy; Ford, Michael; Jones, Richard; Amunugama, Ravi; Allen, David; Urh, Marjeta

    2014-01-01

    .... To specifically address the challenges of understanding the human proteome, we have developed HaloTag technology for protein isolation, particularly strong for isolation of multiprotein complexes...

  14. Forecast-based Integrated Flood Detection System for Emergency Response and Disaster Risk Reduction (Flood-FINDER)

    Science.gov (United States)

    Arcorace, Mauro; Silvestro, Francesco; Rudari, Roberto; Boni, Giorgio; Dell'Oro, Luca; Bjorgo, Einar

    2016-04-01

    Most flood prone areas in the globe are mainly located in developing countries where making communities more flood resilient is a priority. Despite different flood forecasting initiatives are now available from academia and research centers, what is often missing is the connection between the timely hazard detection and the community response to warnings. In order to bridge the gap between science and decision makers, UN agencies play a key role on the dissemination of information in the field and on capacity-building to local governments. In this context, having a reliable global early warning system in the UN would concretely improve existing in house capacities for Humanitarian Response and the Disaster Risk Reduction. For those reasons, UNITAR-UNOSAT has developed together with USGS and CIMA Foundation a Global Flood EWS called "Flood-FINDER". The Flood-FINDER system is a modelling chain which includes meteorological, hydrological and hydraulic models that are accurately linked to enable the production of warnings and forecast inundation scenarios up to three weeks in advance. The system is forced with global satellite derived precipitation products and Numerical Weather Prediction outputs. The modelling chain is based on the "Continuum" hydrological model and risk assessments produced for GAR2015. In combination with existing hydraulically reconditioned SRTM data and 1D hydraulic models, flood scenarios are derived at multiple scales and resolutions. Climate and flood data are shared through a Web GIS integrated platform. First validation of the modelling chain has been conducted through a flood hindcasting test case, over the Chao Phraya river basin in Thailand, using multi temporal satellite-based analysis derived for the exceptional flood event of 2011. In terms of humanitarian relief operations, the EO-based services of flood mapping in rush mode generally suffer from delays caused by the time required for their activation, programming, acquisitions and

  15. The upper bound on the lowest mass halo

    Science.gov (United States)

    Jethwa, P.; Erkal, D.; Belokurov, V.

    2018-01-01

    We explore the connection between galaxies and dark matter haloes in the Milky Way (MW) and quantify the implications on properties of the dark matter particle and the phenomenology of low-mass galaxy formation. This is done through a probabilistic comparison of the luminosity function of MW dwarf satellite galaxies to models based on two suites of zoom-in simulations. One suite is dark-matter-only, while the other includes a disc component, therefore we can quantify the effect of the MW's baryonic disc on our results. We apply numerous stellar-mass-halo-mass (SMHM) relations allowing for multiple complexities: scatter, a characteristic break scale, and subhaloes which host no galaxy. In contrast to previous works, we push the model/data comparison to the faintest dwarfs by modelling observational incompleteness, allowing us to draw three new conclusions. First, we constrain the SMHM relation for 102 2.4 × 108 M⊙ (1σ). Secondly, by translating to a warm dark matter (WDM) cosmology, we bound the thermal relic mass mWDM > 2.9 keV at 95 per cent confidence, on a par with recent constraints from the Lyman-α forest. Lastly, we find that the observed number of ultra-faint MW dwarfs is in tension with the theoretical prediction that reionization prevents galaxy formation in almost all 108 M⊙ haloes. This can be tested with the next generation of deep imaging surveys. To this end, we predict the likely number of detectable satellite galaxies in the Subaru/Hyper Suprime-Cam survey and the Large Synoptic Survey Telescope. Confronting these predictions with future observations will be amongst our strongest tests of WDM and the effect reionization on low-mass systems.

  16. HaloTag as a reporter gene: positron emission tomography imaging with (64)Cu-labeled second generation HaloTag ligands.

    Science.gov (United States)

    Hong, Hao; Benink, Hélène A; Uyeda, H Tetsuo; Valdovinos, Hector F; Zhang, Yin; Meisenheimer, Poncho; Barnhart, Todd E; Fan, Frank; Cai, Weibo

    2013-01-01

    THE GOAL OF THIS STUDY IS TO EMPLOY THE HALOTAG TECHNOLOGY FOR POSITRON EMISSION TOMOGRAPHY (PET), WHICH INVOLVES TWO COMPONENTS: the HaloTag protein (a modified hydrolase which covalently binds to synthetic ligands) and HaloTag ligands (HTLs). 4T1 murine breast cancer cells were stably transfected to express HaloTag protein on the surface (termed as 4T1-HaloTag-ECS, ECS denotes extracellular surface). Two new HTLs were synthesized and termed NOTA-HTL2G-S and NOTA-HTL2G-L (2G indicates second generation, S stands for short, L stands for long, NOTA denotes 1,4,7-triazacyclononane-N,N'N''-triacetic acid). Microscopy studies confirmed surface expression of HaloTag in 4T1-HaloTag-ECS cells, which specifically bind NOTA-HTL2G-S/L. Uptake of (64)Cu-NOTA-HTL2G-L in 4T1-HaloTag-ECS tumors (4.3 ± 0.5, 4.1± 0.2, 4.0 ± 0.2, 2.3 ± 0.1, and 2.2 ± 0.1 %ID/g at 0.5, 3, 6, 18, and 24 h post-injection respectively; n = 4) was significantly higher than that in the 4T1 tumors (3.0 ± 0.3, 3.0± 0.1, 3.0 ± 0.2, 2.0 ± 0.4, and 2.4 ± 0.3 %ID/g at 0.5, 3, 6, 18, and 24 h post-injection respectively; n = 4) at early time points. In comparison, (64)Cu-NOTA-HTL2G-S did not demonstrate significant uptake in either 4T1-HaloTag-ECS or 4T1 tumors. Blocking studies and autoradiography of tumor lysates confirmed that (64)Cu-NOTA-HTL2G-L binds specifically to HaloTag protein in the 4T1-HaloTag-ECS tumors, corroborated by histology. HaloTag protein-specific targeting and PET imaging in vivo with (64)Cu-NOTA-HTL2G-L serves as a proof-of-principle for future non-invasive and sensitive tracking of HaloTag-transfected cells with PET, as well as many other studies of gene/protein/cell function in vivo.

  17. Gravitational lensing of wormholes in the galactic halo region

    Energy Technology Data Exchange (ETDEWEB)

    Kuhfittig, Peter K.F. [Milwaukee School of Engineering, Department of Mathematics, Milwaukee, WI (United States)

    2014-03-15

    A recent study by Rahaman et al. has shown that the galactic halo possesses the necessary properties for supporting traversable wormholes, based on two observational results, the Navarro-Frenk-White density profile and the observed flat rotation curves of galaxies. Using a method for calculating the deflection angle pioneered by V. Bozza, it is shown that the deflection angle diverges at the throat of the wormhole. The resulting photon sphere has a radius of about 0.40 ly. Given the dark-matter background, detection may be possible from past data using ordinary light. (orig.)

  18. Charge Radii and Neutron Correlations in Helium Halo Nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Papadimitriou, Georgios [ORNL; Kruppa, A. T. [Institute of Nuclear Research, Debrecen, Hungary; Michel, N. [University of Jyvaskyla; Nazarewicz, W. [University of Tennessee, Knoxville (UTK) & Oak Ridge National Laboratory (ORNL); Ploszajczak, M. [Grand Accelerateur National d' Ions Lourds (GANIL); Rotureau, J. [University of Arizona

    2011-01-01

    Within the complex-energy configuration interaction framework, we study correlations of valence neutrons to explain the behavior of charge radii in the neutron halo nuclei ^{6,8}He. We find that the experimentally observed decrease of the charge radius between ^{6}He and ^{8}He is caused by a subtle interplay between three effects: dineutron correlations, a spin-orbit contribution to the charge radius, and a core swelling effect. We demonstrate that two-neutron angular correlations in the 2^+}_{1} resonance of ^{6}He differ markedly from the ground-state correlations in ^{6,8}He.

  19. MD 2179: Scraping of off-momentum halo after injection

    CERN Document Server

    Garcia Morales, Hector; Patecki, Marcin; Wretborn, Sven Joel; CERN. Geneva. ATS Department

    2018-01-01

    In this MD, a beam scraping was performed using the momentum primary collimator in IR3 where dispersion is high. A second scraping was performed using a TCSG in IR7 where dispersion is almost negligible. In such a way, we aim to disentangle the contribution of off-momentum particles to halo population. These scrapings will provide useful information to better understand the usual off-momentum losses we see at the start of the ramp. The MD results would also be used to benchmark simulations of off-momentum beam losses in order to gain confidence in simulation models.

  20. Flows of Baryons through the Milky Way Halo

    Science.gov (United States)

    Fox, Andrew J.

    2017-07-01

    The Milky Way provides an ideal opportunity to study baryon flows in the circumgalactic medium of a star-forming spiral galaxy. High velocity clouds (HVCs) seen in UV absorption toward background AGN probe the multi-phase ionized gas in the Galactic CGM. In this talk new observations from the Cosmic Origins Spectrograph (COS) on Hubble will be presented, focusing on two Galactic regions: the biconical outflow from the Galactic Center, which drives gas into the Fermi Bubbles, and the Smith Cloud, an accreting HVC close to the Galactic disk showing clear signs of fragmentation. These observations allow us to constrain the rates of gas circulation in the Galactic halo.