7,076 research outputs found
HZTool and Rivet: Toolkit and Framework for the Comparison of Simulated Final States and Data at Colliders
A common problem in particle physics is the requirement to reproduce
comparisons between data and theory when the theory is a (general purpose)
Monte Carlo simulation and the data are measurements of final state observables
in high energy collisions. The complexity of the experiments, the obervables
and the models all contribute to making this a highly non-trivial task.
We describe an existing library of Fortran routines, HZTool, which enables,
for each measurement of interest, a comparable prediction to be produced from
any given Monte Carlo generator. The HZTool library is being maintained by
CEDAR, with subroutines for various measurements contributed by a number of
authors within and outside the CEDAR collaboration.
We also describe the outline design and current status of a replacement for
HZTool, to be called Rivet (Robust Independent Validation of Experiment and
Theory). This will use an object-oriented design, implemented in C++, together
with standard interfaces (such as HepMC and AIDA) to make the new framework
more flexible and extensible than the Fortran HZTool.Comment: Contribution to CHEP06 conferenc
Effect of lysolecithin on the oxygen uptake of tumour cells, polymorphonuclear leucocytes, lymphocytes and macrophages in vitro.
LYSOLECITHN has been widely studied as a surface-active haemolytic agent (Robinson, 1961) and has been implicated in immune haemolysis (Fischer, 1964), in hypersensitivity reactions (Middleton and Phillips, 1963, 1964), and in the delayed stage of the increase of vascular permeability in inflammation (Cotran and Majno, 1964). Fischer (1964) found that the oxygen uptake (Q02) of tumour cells was reduced by small concentrations of "lysolecithin ", while micro and macrophages responded by an increase Of Q02 and phagocytic activity. We felt that this observation should be confirmed, because it could form the basis of a therapeutic method of increasing the radiosensitivity of tumours by raising the oxygen tension (PO2), and from the theoretical aspect might clarify differences between the cell membranes of tumour and of normal cells. Moreover, Fischer's experiments are open to criticism. His cell suspension was stirred by a moving mercury seal and this could have produced cell damage from mercury poisoning. Also he treated his cell suspensions not with lysolecithin, but with complement plus a specific antibod
HepForge: A lightweight development environment for HEP software
Setting up the infrastructure to manage a software project can become a task
as significant writing the software itself. A variety of useful open source
tools are available, such as Web-based viewers for version control systems,
"wikis" for collaborative discussions and bug-tracking systems, but their use
in high-energy physics, outside large collaborations, is insubstantial.
Understandably, physicists would rather do physics than configure project
management tools.
We introduce the CEDAR HepForge system, which provides a lightweight
development environment for HEP software. Services available as part of
HepForge include the above-mentioned tools as well as mailing lists, shell
accounts, archiving of releases and low-maintenance Web space. HepForge also
exists to promote best-practice software development methods and to provide a
central repository for re-usable HEP software and phenomenology codes.Comment: 3 pages, 0 figures. To be published in proceedings of CHEP06. Refers
to the HepForge facility at http://hepforge.cedar.ac.u
HepData and JetWeb: HEP data archiving and model validation
The CEDAR collaboration is extending and combining the JetWeb and HepData
systems to provide a single service for tuning and validating models of
high-energy physics processes. The centrepiece of this activity is the fitting
by JetWeb of observables computed from Monte Carlo event generator events
against their experimentally determined distributions, as stored in HepData.
Caching the results of the JetWeb simulation and comparison stages provides a
single cumulative database of event generator tunings, fitted against a wide
range of experimental quantities. An important feature of this integration is a
family of XML data formats, called HepML.Comment: 4 pages, 0 figures. To be published in proceedings of CHEP0
Social Tagging: Exploring the Image, the Tags, and the Game
An increasing amount of images are being uploaded, shared, and retrieved on the Web. These large image collections need to be properly stored, organized and easily retrieved. Tags have a key role in image retrieval but it is difficult for those who upload the images to also undertake the quality tag assignment for potential future retrieval by others. Relying on professional keyword assignment is not a practical option for large image collections due to resource constraints. Although a number of content-based image retrieval systems have been launched, they have not demonstrated sufficient utility on large-scale image sources on the web, and are usually used as a supplement to existing text-based image retrieval systems. An alternative to professional image indexing can be social tagging -- with two major types being photo-sharing networks and image labeling games. Here we analyze these applications to evaluate their usefulness from the semantic point of view. We also investigate whether social tagging behaviour can be managed. The findings of the study have shown that social tagging can generate a sizeable number of tags that can be classified as interpretive for an image, and that tagging behaviour has a manageable and adjustable nature depending on tagging guidelines
MSYR—should the information which has become available since selections were made for RMP development in 1987 have changed perceptions on the likely range and relative plausibilities of values for this parameter for baleen whales
It is argued that continued attempts to estimate MSYR from accumulating data, to refine the plausible range of values for this parameter and relative plausibilities within this range, cannot be other than a crucial component of the process of development (and, in due course, refinement) of the Revised Management Procedure (RMP) and of the interpretation of the results of the associated Implementation Simulation Trials (ISTs) for particular RMP applications. In 1987, when the range of MSYR values for RMP trials was first specified, four of the six independent sources of information available suggested definite "low" MSYR values (~1%). None of these four sources appears to have survived to the present. Estimates of MSYR for twenty populations have become available since 1987 - eleven based on population model fits and the balance on the relationship MSYR > r(0)/2. Two arguments advanced previously against the use of this last relationship are considered: the one is dismissed because it lacks support in empirical data, while the other appears negated by an analysis by Best (1993). In the fourteen cases where estimates of MSYR (in terms of uniform selectivity harvesting on the 1+ population) are determined with reasonable precision, most lie in the 2%-6% range, and only one of these has a lower 90 or 95% confidence/probability bound below 1%. Cases of low point estimates of MSYR show wide confidence intervals not incompatible with this 2-6% range. Thus, evidence forthcoming since 1987 (much of it subsequent to 1993 when the Scientific Committee last discussed this issue substantively) would seem to support a change in the Committee's perception at that time of the likely range of values for MSYR for baleen whale stocks, as well as informing judgments on the relative plausibilities of values within this range
Species-Disaggregated Candidate Management Procedures for the South African Merluccius paradoxus and M. capensis Resources
The performance of some initial Fox-model and empirical based candidate OMPs is compared in
terms of expected catches, future CPUE trends and risk to the resource. The examples presented
here should not be viewed as final candidates, but rather “intermediate” examples that are further
guiding the OMP development process
Tips and tricks in designing management procedures
Management procedures (MPs) are becoming widely used in fisheries management, but guidelines to assist in their construction, evaluation, and implementation are few. We provide simple guidelines by drawing on experience from developing and applying MPs in southern Africa and internationally. Suggestions are provided on how to choose between candidate MPs and on key trade-offs in selecting between data-based (empirical) and model-based formulations. Assistance is also provided in dealing with different sources of uncertainty, such as deciding which operating models should be included in a reference set used for primary simulation testing and tuning (in contrast to robustness or sensitivity tests), and on how weights for the associated alternative hypotheses are most practically assigned. Finally, some guidelines are given for presenting the results effectively, which is one of the key challenges of a successful implementation process
Report on an investigation of reasons for differences between outputs from ASPM and ADAPT-VPA assessments of the Gulf of Maine cod stock
The application of ADAPT-VPA and ASPM assessment methods to the same data set for the Gulf of Maine cod stock allows two primary reasons for earlier differences in assessment results from these two approaches to be identified: • the longer period of data which the ASPM method is able to take into account; and • decreasing selectivity at larger ages estimated by the ASPM approach, in contrast to the flat selectivity assumed by the ADAPT-VPA application of Mayo et al. (2002). Arguments are presented that the ASPM approach (with specific details of an application still to be discussed) should be preferred over ADAPT-VPA as the basis for management recommendations for this resource. Since the ASPM assessments consistently indicate the resource status to be appreciably better relative to the MSY biomass, this has important implications for what might constitute appropriate management measures at present
TLEP: A High-Performance Circular e+e- Collider to Study the Higgs Boson
The recent discovery of a light Higgs boson has opened up considerable
interest in circular e+e- Higgs factories around the world. We report on the
progress of the TLEP concept since last year. TLEP is an e+e- circular collider
capable of very high luminosities in a wide centre-of-mass (ECM) spectrum from
90 to 350 GeV. TLEP could be housed in a new 80 to 100 km tunnel in the Geneva
region. The design can be adapted to different ring circumference (e.g. LEP3 in
the 27 km LHC tunnel). TLEP is an ideal complementary machine to the LHC thanks
to high luminosity, exquisite determination of ECM and the possibility of four
interaction points, both for precision measurements of the Higgs boson
properties and for precision tests of the closure of the Standard Model from
the Z pole to the top threshold.Comment: Contribution to IPAC13, 12-17 May 2013, Shanghai, Chin
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