Adaptation to Abundant Low Quality Food Improves the Ability to Compete for Limited Rich Food in Drosophila melanogaster.

The rate of food consumption is a major factor affecting success in scramble competition for a limited amount of easy-to-find food. Accordingly, several studies report positive genetic correlations between larval competitive ability and feeding rate in Drosophila; both become enhanced in populations evolving under larval crowding. Here, we report the experimental evolution of enhanced competitive ability in populations of D. melanogaster previously maintained for 84 generations at low density on an extremely poor larval food. In contrast to previous studies, greater competitive ability was not associated with the evolution of higher feeding rate; if anything, the correlation between the two traits across lines tended to be negative. Thus, enhanced competitive ability may be favored by nutritional stress even when competition is not intense, and competitive ability may be decoupled from the rate of food consumption

A precise measurement of 180 GeV muon energy losses in iron

The energy loss spectrum of 180 GeV muons has been measured with the 5.6 m long finely segmented Module 0 of the ATLAS hadron Tile Calorimeter at the CERN SPS. The differential probability dP/d nu per radiation length of a fractional energy loss nu = DeltaE(mu)/E-mu has been measured in the range 0.025 less than or equal to nu less than or equal to 0.97: it is compared with theoretical predictions for energy losses due to bremsstrahlung, production of electron-positron pairs. and energetic knock-on electrons. The iron elastic form factor correction Delta (el)(Fe) = 1.63 +/-0.17(stat)+/-0.23(syst)+/- (0.20)(0.14theor) to muon bremsstrahlung in the region of no screening of the nucleus by atomic electrons has been measured for the first time, and is compared with different theoretical predictions. RI David, Mario/C-4664-2012; Flix, Josep/G-5414-201

A measurement of the photonuclear interactions of 180 GeV muons in iron

The energy spectrum and the cross section of photonuclear interactions of 180 GeV muons in iron were measured at the CERN SPS using prototype modules of the ATLAS hadron calorimeter. The differential cross section (N-A/A)nudsigma/dnu for a union fractional energy loss nu = E-mu/E-mu was measured in the range 0.1 < nu < 1. The integrated cross section (N-A/A) integral(0.1)(1) nudsigma/dnu is (0.26 +/- 0.03(stat) +/- 0.03(syst)) . 10(-6) cm(2) g(-1) in agreement with the theoretical prediction of 0.267 . 10(-6) cm(2)g(-1). The best adjustment of the data to the theory is achieved for the value of sigma(gamma)N = (115 +/- 18(stat) +/- 15(syst))mub of the photon-nucleon cross section for photons with energies in the range from 18 to 180 GeV

Transport planning for sustainable communities

The lateral and longitudinal profiles of hadronic showers detected by a prototype of the ATLAS Iron-Scintillator Tile Hadron Calorimeter have been investigated. This calorimeter presents a unique longitudinal configuration of scintillator tiles. Using a fine- grained pion beam scan at 100 GeV, a detailed picture of transverse shower behaviour is obtained. The underlying radial energy densities for the four depth segments and for the entire calorimeter have been reconstructed. A three-dimensional hadronic shower parametrisation has been developed. The results presented here are useful for understanding the performance of iron-scintillator calorimeters, for developing fast simulations of hadronic showers, for many calorimetry problems requiring the integration of a shower energy deposition in a volume and for future calorimeters design. (32 refs)

Hadronic shower development in Iron-Scintillator Tile Calorimetry

The lateral and longitudinal profiles of hadronic showers detected by a prototype of the ATLAS Iron-Scintillator Tile Hadron Calorimeter have been investigated. This calorimeter presents a unique longitudinal configuration of scintillator tiles. Using a fine-grained pion beam scan at 100 GeV. a detailed picture of transverse shower behaviour is obtained. The underlying radial energy densities for the four depth segments and for the entire calorimeter have been reconstructed. A three-dimensional hadronic shower parametrisation has been developed. The results presented here are useful for understanding the performance of iron-scintillator calorimeters, for developing fast simulations of hadronic showers, for many calorimetry problems requiring the integration of a shower energy deposition in a volume and for future calorimeters design. (C) 2000 Elsevier Science B.V. All rights reserved. RI David, Mario/C-4664-201

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 e/h 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 +/-1% of the true values and the fractional energy resolution is [(58+/-3)%/rootE+(2.5+/-0.3)%]circle plus(1.7+/-0.2)/E. The value of the e/h ratio obtained for the electromagnetic compartment of the combined calorimeter is 1.74+/-0.04 and agrees with the prediction that e/h &gt; 1.66 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. (C) 2002 Elsevier Science B.V. All rights reserved