103 research outputs found
The PROOF Distributed Parallel Analysis Framework based on ROOT
The development of the Parallel ROOT Facility, PROOF, enables a physicist to
analyze and understand much larger data sets on a shorter time scale. It makes
use of the inherent parallelism in event data and implements an architecture
that optimizes I/O and CPU utilization in heterogeneous clusters with
distributed storage. The system provides transparent and interactive access to
gigabytes today. Being part of the ROOT framework PROOF inherits the benefits
of a performant object storage system and a wealth of statistical and
visualization tools. This paper describes the key principles of the PROOF
architecture and the implementation of the system. We will illustrate its
features using a simple example and present measurements of the scalability of
the system. Finally we will discuss how PROOF can be interfaced and make use of
the different Grid solutions.Comment: Talk from the 2003 Computing in High Energy and Nuclear Physics
(CHEP03), La Jolla, CA, USA, March 2003, 5 pages, LaTeX, 4 eps figures. PSN
TULT00
ROOT Status and Future Developments
In this talk we will review the major additions and improvements made to the
ROOT system in the last 18 months and present our plans for future
developments. The additons and improvements range from modifications to the I/O
sub-system to allow users to save and restore objects of classes that have not
been instrumented by special ROOT macros, to the addition of a geometry package
designed for building, browsing, tracking and visualizing detector geometries.
Other improvements include enhancements to the quick analysis sub-system
(TTree::Draw()), the addition of classes that allow inter-file object
references (TRef, TRefArray), better support for templated and STL classes,
amelioration of the Automatic Script Compiler and the incorporation of new
fitting and mathematical tools. Efforts have also been made to increase the
modularity of the ROOT system with the introduction of more abstract interfaces
and the development of a plug-in manager. In the near future, we intend to
continue the development of PROOF and its interfacing with GRID environments.
We plan on providing an interface between Geant3, Geant4 and Fluka and the new
geometry package. The ROOT GUI classes will finally be available on Windows and
we plan to release a GUI inspector and builder. In the last year, ROOT has
drawn the endorsement of additional experiments and institutions. It is now
officially supported by CERN and used as key I/O component by the LCG project.Comment: Talk from the 2003 Computing in High Energy and Nuclear Physics
(CHEP03), La Jolla, Ca, USA, March 2003, 5 pages, MSWord, pSN MOJT00
FROM 3D IMAGING OF STRUCTURES TO DIFFUSIVE PROPERTIES OF ANISOTROPIC CELLULAR MATERIALS
International audienceThis paper deals with diffusive properties phenomena in metallic foams. We have developed a 3D morphological tool to extract geometrical characteristics of the media from X-ray images. The anisotropy of the geometry of each phase is observed and the relationship between microstructure and effective properties is analyzed. We emphasize on geometrical tortuosity determination and impact on con¬ductive transport tensor. The conductive heat transfers are computed on a vertex-edge network to determine directional effective conductivities by solving the energy equa¬tion on this network. We realize a systematic study carried on a wide range of different Nickel foam samples. Finally, we propose a simple model of effective diffusion prop¬erties dependence on tortuosity and porosity
Bitmap indices for fast end-user physics analysis in root.
Most physics analysis jobs involve multiple selection steps on the input data. These selection steps are called cuts or queries. A common strategy to implement these queries is to read all input data from files and then process the queries in memory. In many applications the number of variables used to define these queries is a relative small portion of the overall data set therefore reading all variables into memory takes unnecessarily long time. In this paper we describe an integration effort that can significantly reduce this unnecessary reading by using an efficient compressed bitmap index technology. The primary advantage of this index is that it can process arbitrary combinations of queries very efficiently, while most other indexing technologies suffer from the "curse of dimensionality" as the number of queries increases. By integrating this index technology with the ROOT analysis framework, the end-users can benefit from the added efficiency without having to modify their analysis programs. Our performance results show that for multi-dimensional queries, bitmap indices outperform the traditional analysis method up to a factor of 10
MCG+00-32-16: An Irregular Galaxy Close to the Lowest Redshift Absorber on the 3C 273 Line of Sight
MCG+00-32-16 is the galaxy closest in position-velocity space to the lowest
redshift Ly absorber along the line-of-sight to the quasar 3C 273. Its
projected separation is 204 (d/19 Mpc) kpc, where d is the distance from the
Milky Way to the galaxy, and the redshift difference is only 94 km/s; HI
1225+01 is slightly closer in projected separation to the absorber, but has a
greater redshift difference. We present HI synthesis array mapping and CCD
photometry in B and R for MCG+00-32-16. The HI disk is rotating in such a way
that the side of the galaxy closer to the sight-line to the quasar has the
larger velocity difference from the absorber. The absorber may be a ``failed
dwarf'' member of a poor galaxy group of which MCG+00-32-16 and HI 1225+01 are
the only members to have formed stars.Comment: 14 pages, 9 figures, accepted by Astrophysical Journa
ROOT - A C++ Framework for Petabyte Data Storage, Statistical Analysis and Visualization
ROOT is an object-oriented C++ framework conceived in the high-energy physics
(HEP) community, designed for storing and analyzing petabytes of data in an
efficient way. Any instance of a C++ class can be stored into a ROOT file in a
machine-independent compressed binary format. In ROOT the TTree object
container is optimized for statistical data analysis over very large data sets
by using vertical data storage techniques. These containers can span a large
number of files on local disks, the web, or a number of different shared file
systems. In order to analyze this data, the user can chose out of a wide set of
mathematical and statistical functions, including linear algebra classes,
numerical algorithms such as integration and minimization, and various methods
for performing regression analysis (fitting). In particular, ROOT offers
packages for complex data modeling and fitting, as well as multivariate
classification based on machine learning techniques. A central piece in these
analysis tools are the histogram classes which provide binning of one- and
multi-dimensional data. Results can be saved in high-quality graphical formats
like Postscript and PDF or in bitmap formats like JPG or GIF. The result can
also be stored into ROOT macros that allow a full recreation and rework of the
graphics. Users typically create their analysis macros step by step, making use
of the interactive C++ interpreter CINT, while running over small data samples.
Once the development is finished, they can run these macros at full compiled
speed over large data sets, using on-the-fly compilation, or by creating a
stand-alone batch program. Finally, if processing farms are available, the user
can reduce the execution time of intrinsically parallel tasks - e.g. data
mining in HEP - by using PROOF, which will take care of optimally distributing
the work over the available resources in a transparent way
FLNC Gene Splice Mutations Cause Dilated\ua0Cardiomyopathy
OBJECTIVE:
To identify novel dilated cardiomyopathy (DCM) causing genes, and to elucidate the pathological mechanism leading to DCM by utilizing zebrafish as a model organism.
BACKGROUND:
DCM, a major cause of heart failure, is frequently familial and caused by a genetic defect. However, only 50% of DCM cases can be attributed to a known DCM gene variant, motivating the ongoing search for novel disease genes.
METHODS:
We performed whole exome sequencing (WES) in two multigenerational Italian families and one US family with arrhythmogenic DCM without skeletal muscle defects, in whom prior genetic testing had been unrevealing. Pathogenic variants were sought by a combination of bioinformatic filtering and cosegregation testing among affected individuals within the families. We performed function assays and generated a zebrafish morpholino knockdown model.
RESULTS:
A novel filamin C gene splicing variant (FLNC c.7251+1 G>A) was identified by WES in all affected family members in the two Italian families. A separate novel splicing mutation (FLNC c.5669-1delG) was identified in the US family. Western blot analysis of cardiac heart tissue from an affected individual showed decreased FLNC protein, supporting a haploinsufficiency model of pathogenesis. To further analyze this model, a morpholino knockdown of the ortholog filamin Cb in zebrafish was created which resulted in abnormal cardiac function and ultrastructure.
CONCLUSIONS:
Using WES, we identified two novel FLNC splicing variants as the likely cause of DCM in three families. We provided protein expression and in vivo zebrafish data supporting haploinsufficiency as the pathogenic mechanism leading to DCM
Status Report of the DPHEP Study Group: Towards a Global Effort for Sustainable Data Preservation in High Energy Physics
Data from high-energy physics (HEP) experiments are collected with
significant financial and human effort and are mostly unique. An
inter-experimental study group on HEP data preservation and long-term analysis
was convened as a panel of the International Committee for Future Accelerators
(ICFA). The group was formed by large collider-based experiments and
investigated the technical and organisational aspects of HEP data preservation.
An intermediate report was released in November 2009 addressing the general
issues of data preservation in HEP. This paper includes and extends the
intermediate report. It provides an analysis of the research case for data
preservation and a detailed description of the various projects at experiment,
laboratory and international levels. In addition, the paper provides a concrete
proposal for an international organisation in charge of the data management and
policies in high-energy physics
Plasma CC16 levels are associated with development of ALI/ARDS in patients with ventilator-associated pneumonia: a retrospective observational study
<p>Abstract</p> <p>Background</p> <p>Despite consensus criteria, diagnosing acute lung injury, or its more severe form acute respiratory distress syndrome (ALI/ARDS) remains challenging. Adding objective measures, such as plasma levels of biological markers could facilitate recognition of ALI/ARDS. This study was designed to assess and compare the diagnostic accuracy of biological markers for ALI/ARDS with ventilator-associated pneumonia (VAP).</p> <p>Methods</p> <p>We performed serial measurements of Clara cell protein (CC16), soluble receptor for advanced glycation end products (sRAGE), surfactant protein D (SP-D) and Krebs von den Lungen (KL-6) in plasma of patients with VAP and mechanically ventilated control patients without VAP. ALI/ARDS was diagnosed using the criteria of the North-American European consensus conference.</p> <p>Results</p> <p>Thirty-seven patients were enrolled - 22 patients with VAP and 15 control patients. Ten patients with pneumonia met the ALI/ARDS consensus criteria. Control patients never met these criteria. Plasma CC16 had a good diagnostic capacity for ALI/ARDS as shown by the receiver operating characteristic curve with an area under the curve of 0.91 (95% confidence interval (CI) 0.79 - 1.00; <it>p </it>< 0.001). Identification of ALI/ARDS patients by sudden increases in plasma CC16 of 30% or more yielded a sensitivity of 90% and a specificity of 92%. Of note, levels of CC16 increased 2 days before ALI/ARDS diagnosis. A cut-off level of 50 ng/ml SP-D yielded a specificity of 100% while the sensitivity was 70%. The area under the curve for SP-D was 0.80 (95% CI 0.58 - 1.00; <it>p </it>= 0.02). The diagnostic accuracies of KL-6 and sRAGE were low.</p> <p>Conclusion</p> <p>Plasma CC16 seems a potential biological marker for ALI/ARDS in patients with VAP. Plasma levels of sRAGE, SP-D and KL-6 have limited discriminative power for diagnosing ALI/ARDS in VAP.</p
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