Measurement of the Charge Ratio of Atmospheric Muons with the CMS Detector

This paper describes a new measurement of the flux ratio of positive and negative muons from cosmic-ray interactions in the atmosphere, using data collected by the CMS detector at ground level and in the underground experimental cavern. The excellent performance of the CMS detector allowed detection of muons in the momentum range from 3 GeV to 1 TeV. For muon momenta below 100 GeV the flux ratio is measured to be a constant $1.2766 \pm 0.0032(stat) \pm 0.0032(syst)$, the most precise measurement to date. At higher momenta an increase in the charge asymmetry is observed, in agreement with models of muon production in cosmic-ray showers and compatible with previous measurements by deep-underground experiments.Comment: Invited talk given at XVI International Symposium on Very High Energy Cosmic Ray Interactions (ISVHECRI 2010), Batavia, IL, USA, 28 June - 2 July 2010. 4 page

W/Z + jet Production at the LHC

This paper summarises results on W and Z plus jet production in pp collisions at $\sqrt{s} = 7$ TeV at the CERN Large Hadron Collider, from both the ATLAS and CMS experiments. Based on the 2010 and 2011 datasets, measurements have been made of numerous cross sections providing excellent tests of the latest predictions from QCD calculations and event generators.Comment: 4 pages, proceedings of the Rencontres du Blois, May 201

Resistor monitors transfer of liquid helium

Large resistance change of a carbon resistor at the liquid helium temperature distinguishes between the transfer of liquid helium and gaseous helium into a closed Dewar. The resistor should be physically as small as possible to reduce the heat load to the helium

Multilevel selection models using gllamm

Models for handling sample selection or informative missingness have been developed for both cross sectional and longitudinal or panel data. For cross sectional data, Heckman (1979) suggested a joint model for the response and sample selection processes where the disturbances of the processes are correlated. For longitudinal data, Hausman and Wise (1979) and Diggle and Kenward (1994) developed a model in which the continuous response (observed or unobserved), and possibly the lagged response, is a predictor of attrition or dropout. The Heckman model can be estimated using the heckman command in Stata and the Diggle-Kenward model is available in the Oswald package running in S-PLUS. Both models can also be estimated using gllamm with the advantage that the following three generalisations are possible. First, the models can be extended to multilevel settings where there may be unobserved heterogeneity between the clusters at the different levels in both the substantive and selection processes and where selection may operate at several levels. Second, the Heckman model can be modified for non-normal response processes. Third, both the Heckman and Diggle-Kenward models can be extended to situations where the substantive response is a latent variable measured by a number of indicators. I will show how the standard Heckman and Diggle-Kenward models are estimated in gllamm and give a examples of all three types of generalisation of these standard models. The research was carried out jointly with Anders Skrondal and Andrew Pickles.

The use of case studies in researching the conversion to organic farming systems

This poster reviews the use of case studies in studying farms converting to organic production. Particular reference is made to the 'Conversion to organic field vegetable production' project, which is making use of case studies. Case studies facilitate an in depth analysis of a farm during the conversion to organic production and enable researchers and farmers to gain a greater understanding of the complex changes that take place. Case studies also provide a valuable tool for disseminating the result

Children\u27s after-school activity : associations with weight status and family circumstance

This study investigated children\u27s after-school activity and associations with body mass index (BMI) and family circumstance. One thousand two hundred thirty-four parents and 854 children (age 8-13 years) completed activity diaries for the 2 hours after school. Parents reported children as more active than children reported themselves. Boys were reported to be more active than girls. Activity levels were generally not associated with BMI or family circumstance with the exception of cultural background. Parent-reported mean child METs were higher for mothers born in Australia (3.3 vs. 3.0; p = .02). Child-reported mean METs were higher for fathers born in Australia (2.9 vs. 2.6; p = .04) and where English was their main language (2.9 vs. 2.3, p = .003).<br /