Production of W and Z bosons accompanied by jets at LHC startup

We report on potential for measurement of W and Z boson production accompanied by jets at the CMS experiment. Of particular interest are jet multiplicity and Pt distributions. The 10/pb to 100/pb datasets expected in the startup year of operation of LHC are likely to already provide information beyond the reach of the Tevatron collider both in jet multiplicity and Pt range. We are especially interested in understanding the ratios of W+jets to Z+jets distributions by comparing them to next-to-leading order Monte Carlo generators, as these processes present a formidable background for searches of new physics phenomena.Comment: Poster session at ICHEP08, Philadelphia, USA, July 2008. 3 pages, LaTeX, 1 jpg figure. Updated with the new latex template for ICHEP0

A review on non iterative closed form configuration matching and rotations estimation

Orthonormal matrices, Procrustes and quaternion analysis are closed form solutions of the configuration matching problem, common in geodesy as in the datum transformation problem. Literature reports more Procrustes based geodetic applications than Quaternions, which are more used in other application fields, such as aerospace navigation, robotics and computer vision. The large popularity of Procrustes in geodesy is mainly due to its capability to take into account a priori observation weighting in a simple wa

Coupling radio propagation and weather forecast models to maximize Ka-band channel transmission rate for interplanetary missions

Deep space (DS) missions for interplanetary explorations are aimed at acquiring information about the solar system and its composition. To achieve this result a radio link is established between the space satellite and receiving stations on the Earth. Significant channel capacity must be guaranteed to such spacecraft-to-Earth link considering their large separation distance as well. Terrestrial atmospheric impairments on the space-to-Earth propagating signals are the major responsible for the signal degradation thus reducing the link’s channel temporal availability. Considering the saturation and the limited bandwidth of the conventional systems used working at X-band (around 8.4 GHz), frequencies above Ku-band (12-18 GHz) are being used and currently explored for next future DS missions. For example, the ESA mission EUCLID, planned to be launched in 2020 to reach Sun-Earth Lagrange point L2, will use the K-band (at 25.5-27 GHz). The BepiColombo (BC) ESA mission to Mercury, planned to be launched in 2016, will use Ka-band (at 32-34 GHz) with some modules operating at X-band too. The W-band is also being investigated for space communications (Lucente et al., IEEE Systems J., 2008) as well as near-infrared band for DS links (Luini at al., 3rd IWOW, 2014; Cesarone et al., ICSOS, 2011). If compared with X-band channels, K-band and Ka-band can provide an appealing data rate and signal-to-noise ratio in free space due to the squared-frequency law increase of antenna directivity within the downlink budget (for the same physical antenna size). However, atmospheric path attenuation can be significant for higher frequencies since the major source of transmission outage is not only caused by convective rainfall, as it happens for lower frequencies too, but even non-precipitating clouds and moderate precipitation produced by stratiform rain events are detrimental. This means that accurate channel models are necessary for DS mission data link design at K and Ka band. A physical approach can offer advanced radiopropagation models to take into account the effects due to atmospheric gases, clouds and precipitation. The objective of this work is to couple a weather forecast numerical model with a microphysically- oriented radiopropagation model, providing a description of the atmospheric state and of its effects on a DS downlink. This work is developed in the framework of the RadioMeteorological Operations Planner (RMOP) program, aimed at performing a feasibility study for the BC mission (Biscarini et al., EuCAP 2014). The RMOP chain for the link budget computation is composed by three modules: weather forecast (WFM), radio propagation (RPM) and downlink budget (DBM). WFM is aimed at providing an atmospheric state vector. Among the available weather forecast models, for RMOP purposes we have used the Mesoscale Model 5. The output of the WFM is the input of the RPM for the computation of the atmospheric attenuation and sky-noise temperature at the receiving ground station antenna. RPM makes use of radiative transfer solver based on the Eddington approximations well as accurate scattering models. Time series of attenuation and sky-noise temperature coming from the RPM are converted into probability density functions and then ingested by the DBM to compute the received data volume (DV). Using the BC mission as a reference test case for the Ka-band ground station at Cebreros (Spain), this work will show the advantages of using a coupled WFM-RPM approach with respect to climatological statistics in a link budget optimization procedure. The signal degradation due to atmospheric effects in DS links in terms of received DV will be also investigated not only at Ka band, but also at X, K and W for intercomparison. The quality of the DS downlink will be given in terms of received DV and the results at different frequencies compared showing the respective advantages and drawbacks

Paroxysmal Atrial Fibrillation Triggered By A Monomorphic Ventricular Couplet In A Patient With Acute Coronary Syndrome

Atrial fibrillation is a common arrhythmia in patients suffering from acute myocardial infarction, however its pathophysiological mechanisms are not fully understood. We describe the unusual case of a 76-year old woman admitted for non-ST-segment elevation myocardial infarction, who developed multiple episodes of paroxysmal atrial fibrillation triggered by monomorphic ventricular couplets. Beta-blocking and amiodarone therapy resulted efficacious in preventing arrhythmic recurrences. We then discuss the possible arrhythmogenic mechanisms, with special emphasis on the unique electrophysiological, hemodynamic, cellular and anatomical milieu created by acute myocardial ischemia

A History of Group Theory through the Lives of Group Theorists: Sophus Lie - Part 1

We continue here our attempt of a systematic historical account of Group Theory inspected by means of the lives and the works of its main actors. The aim is to bring the interested reader through orig- inal correspondences, published and unpublished works, historical perspectives, diatribes and friendships. This issue contains the translation of a memory of Sophus Lie writ- ten by Ludwig Sylow. It was published in the 1899 issue of Archiv for Mathematik of Naturvidenskab soon after Lie’s death. We are grateful to Gunnar Traustason for his translation from Nor- wegian

Selective transcriptional regulation by Myc: Experimental design and computational analysis of high-throughput sequencing data

AbstractThe gene expression programs regulated by the Myc transcription factor were evaluated by integrated genome-wide profiling of Myc binding sites, chromatin marks and RNA expression in several biological models. Our results indicate that Myc directly drives selective transcriptional regulation, which in certain physiological conditions may indirectly lead to RNA amplification. Here, we illustrate in detail the experimental design concerning the high-throughput sequencing data associated with our study (Sabò et al., Nature. (2014) 511:488–492) and the R scripts used for their computational analysis

Conduit geometry and evolution of effusion rate during basaltic effusive events: Insights from numerical modeling

The dynamics of effusive events is controlled by the interplay between conduit geometry and source conditions. Dyke-like geometries have been commonly employed for describing conduits during effusive eruptions, but their depth-dependent and temporal modifications are largely unknown. Here we present a novel model that describes the evolution of conduit geometry during effusive eruptions by using a quasisteady state approach based on a 1D conduit model and appropriate criteria to model the geometric evolution of the conduit due to fluid shear stress and elastic deformation. Such approach provides time-dependent trends for effusion rate, conduit geometry, exit velocity and gas flow, among other output variables. Fluid shear stress leads to upward widening conduits, whereas elastic deformation becomes relevant only during final phases of the eruptions. Since the model is able to reproduce different trends of effusion rate, it was employed for addressing the effects of magma source conditions and conduit properties on the main characteristics of the resulting effusive eruptions (e.g. duration, erupted mass, maximum effusion rate). We show that the total erupted mass is mainly controlled by magma reservoir dimensions and their conditions before the eruption (i.e., initial overpressure), whereas conduit processes and geometry are able to affect the magma withdrawal rate and thus the eruption duration and effusion rate. The resulting effusion rate trends were classified in different types, and associated to the curves described in the literature for different volcanic events. Results well reproduce these trends and provide new insights for interpreting them, highlighting the importance of reservoir overpressure and the initial dimensions of the feeding dyke on the resulting effusion rate curve