113 research outputs found
Hadron Energy Reconstruction for the ATLAS Calorimetry in the Framework of the Non-parametrical Method
This paper discusses hadron energy reconstruction for the ATLAS barrel
prototype combined calorimeter (consisting of a lead-liquid argon
electromagnetic part and an iron-scintillator hadronic part) in the framework
of the non-parametrical method. The non-parametrical method utilizes only the
known ratios and the electron calibration constants and does not require
the determination of any parameters by a minimization technique. Thus, this
technique lends itself to an easy use in a first level trigger. The
reconstructed mean values of the hadron energies are within of the
true values and the fractional energy resolution is . The value of the ratio
obtained for the electromagnetic compartment of the combined calorimeter is
and agrees with the prediction that for this
electromagnetic calorimeter. Results of a study of the longitudinal hadronic
shower development are also presented. The data have been taken in the H8 beam
line of the CERN SPS using pions of energies from 10 to 300 GeV.Comment: 33 pages, 13 figures, Will be published in NIM
PYTHIA 6.4 Physics and Manual
The PYTHIA program can be used to generate high-energy-physics `events', i.e.
sets of outgoing particles produced in the interactions between two incoming
particles. The objective is to provide as accurate as possible a representation
of event properties in a wide range of reactions, within and beyond the
Standard Model, with emphasis on those where strong interactions play a role,
directly or indirectly, and therefore multihadronic final states are produced.
The physics is then not understood well enough to give an exact description;
instead the program has to be based on a combination of analytical results and
various QCD-based models. This physics input is summarized here, for areas such
as hard subprocesses, initial- and final-state parton showers, underlying
events and beam remnants, fragmentation and decays, and much more. Furthermore,
extensive information is provided on all program elements: subroutines and
functions, switches and parameters, and particle and process data. This should
allow the user to tailor the generation task to the topics of interest.Comment: 576 pages, no figures, uses JHEP3.cls. The code and further
information may be found on the PYTHIA web page:
http://www.thep.lu.se/~torbjorn/Pythia.html Changes in version 2: Mistakenly
deleted section heading for "Physics Processes" reinserted, affecting section
numbering. Minor updates to take into account referee comments and new colour
reconnection option
The effects of Hyperoxia on Repeated Sprint Cycle Performance and Muscle Fatigue
Objectives: Hyperoxia (> 21% oxygen) can evoke performance improvements in aerobic and anaerobic exercise. The aims of the current study were to determine the effects of breathing hyperoxic gas (fraction of inspired oxygen [FiO2] 1.00) on repeated cycle performance, and to assess the nature and extent of fatigue after intermittent sprinting.
Design & Methods: Testing (n=14 males) comprised two visits to the laboratory. Each session involved 10 x 15s repeated cycle sprints breathing FiO2 1.00 (hyperoxia) or FiO2 0.21 (normoxia). Muscle fatigue was measured pre and post sprints using maximal voluntary contraction (MVC), voluntary activation (VA) and potentiated doublet twitch (PTF). Blood lactate (BLa) was taken between sprints.
Paired samples t-tests were used to examine difference between conditions in power output (peak and mean Watts) and BLa. Two-way ANOVA was used to examine fatigue variables pre and post sprints according to condition.
Results: Mean power output was 4% greater in hyperoxia (p0.05). There was a significant increase in BLa in hyperoxia compared with normoxia (p0.05) in response to the cycling, although a large drop in PTF occurred in both conditions.
Conclusion: Hyperoxia can elicit improvements in mean cycling power, with no significant change in post exercise muscle fatigue. Hyperoxia as a training aid may provide performance enhancing effects during repeated sprint cycling by reducing concurrent muscle fatigue, primarily via peripheral factors
No effect of glutamine supplementation and hyperoxia on oxidative metabolism and performance during high-intensity exercise.
addresses: Health and Biology, Liverpool Hope University, Liverpool, UK. [email protected]: Comparative Study; Journal ArticleThis is an Author's Accepted Manuscript of an article published in Journal of Sports Sciences, 2008, Vol. 26, Issue 10, pp. 1081 – 1090 © 2008 copyright Taylor & Francis, available online at: http://www.tandfonline.com/doi/abs/10.1080/02640410801930200Glutamine enhances the exercise-induced expansion of the tricarboxylic acid intermediate pool. The aim of the present study was to determine whether oral glutamine, alone or in combination with hyperoxia, influenced oxidative metabolism and cycle time-trial performance. Eight participants consumed either placebo or 0.125 g kg body mass(-1) of glutamine in 5 ml kg body mass(-1) placebo 1 h before exercise in normoxic (control and glutamine respectively) or hyperoxic (FiO(2) = 50%; hyperoxia and hyperoxia + glutamine respectively) conditions. Participants then cycled for 6 min at 70% maximal oxygen uptake (VO(2max)) immediately before completing a brief high-intensity time-trial (approximately 4 min) during which a pre-determined volume of work was completed as fast as possible. The increment in pulmonary oxygen uptake during the performance test (DeltaVO(2max), P = 0.02) and exercise performance (control: 243 s, s(x) = 7; glutamine: 242 s, s(x) = 3; hyperoxia: 231 s, s(x) = 3; hyperoxia + glutamine: 228 s, s(x) = 5; P < 0.01) were significantly improved in hyperoxic conditions. There was some evidence that glutamine ingestion increased DeltaVO(2max) in normoxia, but not hyperoxia (interaction drink/FiO(2), P = 0.04), but there was no main effect or impact on performance. Overall, the data show no effect of glutamine ingestion either alone or in combination with hyperoxia, and thus no limiting effect of the tricarboxylic acid intermediate pool size, on oxidative metabolism and performance during maximal exercise
Construction and test of a fine-grained liquid argon preshower prototype
A separate liquid argon preshower detector consisting of two layers featuring a fine granularity of 2.5~10 was studied by the RD3 collaboration. A prototype covering approximately 0.8 in pseudo-rapidity and 9 degrees in azimuth was built and tested at CERN in July 94. CMOS and GaAs VLSI preamplifiers were designed and tested for this occasion. The combined response of this detector and an accordion electromagnetic calorimeter prototype to muons, electrons and photons is presented. For minimum ionizing tracks a signal-to-noise ratio of 4.5 per preshower layer was measured. Above 150~GeV the space resolution for electrons is better than 250~m in both directions. The precision on the electromagnetic shower direction, determined together with the calorimeter, is better than 4 mrad above 50~GeV. It is concluded that the preshower detector would adequately fulfil its role for future operation at CERN Large Hadron Collider
Test beam results of a stereo preshower integrated in the liquid argon accordion calorimeter
This paper describes the construction of an integrated preshower within the RD3 liquid argon accordion calorimeter. It has a stereo view which enables the measurement of two transverse coordinates. The prototype was tested at CERN with electrons, photons and muons to validate its capability to work at LHC ( Energy resolution, impact point resolution, angular resolution, / rejection )
Construction and test of a fine-grained liquid argon preshower prototype
A separate liquid argon preshower detector consisting of two layers featuring a fine granularity of 2.5~10 was studied by the RD3 collaboration. A prototype covering approximately 0.8 in pseudo-rapidity and 9 degrees in azimuth was built and tested at CERN in July 94. CMOS and GaAs VLSI preamplifiers were designed and tested for this occasion. The combined response of this detector and an accordion electromagnetic calorimeter prototype to muons, electrons and photons is presented. For minimum ionizing tracks a signal-to-noise ratio of 4.5 per preshower layer was measured. Above 150~GeV the space resolution for electrons is better than 250~m in both directions. The precision on the electromagnetic shower direction, determined together with the calorimeter, is better than 4 mrad above 50~GeV. It is concluded that the preshower detector would adequately fulfil its role for future operation at CERN Large Hadron Collider
Test beam results of a stereo preshower integrated in the liquid argon accordion calorimeter
This paper describes the construction of an integrated preshower within the RD3 liquid argon accordion calorimeter. It has a stereo view which enables the measurement of two transverse coordinates. The prototype was tested at CERN with electrons, photons and muons to validate its capability to work at LHC (Energy resolution, impact point resolution, angular resolution, π o γ rejection). (Elsevier
Results from a combined test of an electromagnetic liquid argon calorimeter with a hadronic scintillating-tile calorimeter
The first combined test of an electromagnetic liquid argon accordion calorimeter and a hadronic scintillating-tile calorimeter was carried out at the CERN SPS. These devices are prototypes of the barrel calorimeter of the future ATLAS experiment at the LHC. The energy resolution of pions in the energy range from 20 to 300~GeV at an incident angle of about 11 is well-described by the expression \sigma/E = ((46.5 \pm 6.0)\%/\sqrt{E} +(1.2 \pm 0.3)\%) \oplus (3.2 \pm 0.4)~\mbox{GeV}/E. Shower profiles, shower leakage, and the angular resolution of hadronic showers were also studied
Pathogens and host immunity in the ancient human oral cavity.
Calcified dental plaque (dental calculus) preserves for millennia and entraps biomolecules from all domains of life and viruses. We report the first, to our knowledge, high-resolution taxonomic and protein functional characterization of the ancient oral microbiome and demonstrate that the oral cavity has long served as a reservoir for bacteria implicated in both local and systemic disease. We characterize (i) the ancient oral microbiome in a diseased state, (ii) 40 opportunistic pathogens, (iii) ancient human-associated putative antibiotic resistance genes, (iv) a genome reconstruction of the periodontal pathogen Tannerella forsythia, (v) 239 bacterial and 43 human proteins, allowing confirmation of a long-term association between host immune factors, 'red complex' pathogens and periodontal disease, and (vi) DNA sequences matching dietary sources. Directly datable and nearly ubiquitous, dental calculus permits the simultaneous investigation of pathogen activity, host immunity and diet, thereby extending direct investigation of common diseases into the human evolutionary past
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