Operation of the ATLAS Semiconductor Tracker: commissioning and performance results with cosmic ray data

The Semiconductor Tracker (SCT) is one of the three sub-systems of the ATLAS internal tracker. Its complete installation and sign-off took about 18 months and was finished at the beginning of 2008. Since then, the SCT has been run successfully taking data in combined mode with the other ATLAS sub-systems. The major problems related with cooling failures and the mortality of off-detector opto-chips have been solved. As in summer 2009, more than 99% of the main detector components are fully working. Detailed calibration procedures have been applied to optimize the detector performance. An initial alignment has been achieved using cosmic ray real data. Some results in terms of tracking performance and Lorentz angle measurements are also shown

Clinical characteristics and risk of relapse for patients with stage I-II diffuse large B cell lymphoma treated in first line with immunochemotherapy

Diffuse large b-cell lymphoma (DLBCL) is an aggressive and potentially curable lymphoma that presents itself as stage I-II in 30% of all cases. It is known that in these localized stages, 15-20% of patients treated without rituximab eventually relapse, but less data exist regarding rituximab era. We have analyzed clinico-pathological features and risk of relapse in 98 patients with I-II stage DLBCL in complete response (CR) or unconfirmed CR (CRu) after first-line treatment consisting of immunochemotherapy. Twelve patients (12.2%) eventually relapsed. Late relapse, more than two years after diagnosis, occurred in three patients, and early relapse, less than two years after diagnosis, was documented in nine patients. Median time from diagnosis to relapse was 0.61 years for patients with early relapse and 3.66 years for patients with late relapse. The second CR rate obtained was similar in the late and in early relapsing patients, being 33% versus 44% (p = 0.072), respectively. Three-year overall survival (OS) was 22% for early relapsing patients and 33% for late relapsing patients (p = 0.65). In conclusion, patients who are diagnosed with stage I-II DLBCL and achieve a CR/CRu with first line immunochemotherapy have a good prognosis. However, a proportion of patients relapse, and this is less frequent in patients treated with first line with immunochemotherapy. These patients have a poor prognosis

Luminiscent and Magnetic Tb-MOF Flakes Deposited on Silica

The synthesis of a terbium-based 2D metal-organic framework (MOF), of formula [Tb(MeCOO)(PhCOO)2] (1), a crystalline material formed by neutral nanosheets held together by Van der Waals interactions, is presented. The material can be easily exfoliated by sonication and deposited onto different substrates. Uniform distributions of Tb-2D MOF flakes onto silicon were obtained by spin-coating. We report the luminescent and magnetic properties of the deposited flakes compared with those of the bulk. Complex 1 is luminescent in the visible and has a sizeable quantum yield of QY = 61% upon excitation at 280 nm. Photoluminescence measurements performed using a micro-Raman set up allowed us to characterize the luminescent spectra of individual flakes on silicon. Magnetization measurements of flakes-on-silicon with the applied magnetic field in-plane and out-of-plane display anisotropy. Ac susceptibility measurements show that 1 in bulk exhibits field-induced slow relaxation of the magnetization through two relaxation paths and the slowest one, with a relaxation time of tlf ⇡ 0.5 s, is assigned to a direct process mechanism. The reported exfoliation of lanthanide 2D-MOFs onto substrates is an attractive approach for the development of multifunctional materials and devices for different applications

ATLAS silicon module assembly and qualification tests at IFIC Valencia

ATLAS experiment, designed to probe the interactions of particles emerging out of proton proton collisions at energies of up to 14 TeV, will assume operation at the Large Hadron Collider (LHC) at CERN in 2007. This paper discusses the assembly and the quality control tests of forward detector modules for the ATLAS silicon microstrip detector assembled at the Instituto de Fisica Corpuscular (IFIC) in Valencia. The construction and testing procedures are outlined and the laboratory equipment is briefly described. Emphasis is given on the module quality achieved in terms of mechanical and electrical stability.Comment: 23 pages, 38 EPS figures, uses JINST LaTeX clas

Forward SCT Module Assembly and Quality Control at IFIC Valencia

This note discusses the assembly and the quality control tests of 282 forward detector modules for the ATLAS Semiconductor Tracker assembled at the Instituto de Fisica Corpuscular (IFIC) in Valencia. The construction and testing procedures are outlined and the laboratory equipment is briefly described. Emphasis is given on the module quality achieved in terms of mechanical and electrical stability

Aplicación de la topología molecular al análisis de la actividad antimalárica de 4-Aminobiciclo[2.2.2]Octan-2-il 4-Aminobutanoatos y sus análogos etanoatos y propanoatos

La malaria es una enfermedad que causa uno de los mayores índices de mortalidad en todo el mundo. Actualmente, el número de casos y muertes continúa en aumento, debido a, entre otros factores, la resistencia que el parásito ha desarrollado frente a los tratamientos. Con el tiempo, se han estudiado nuevas moléculas para ser utilizadas como tratamiento frente a esta enfermedad. En este estudio se realizó un análisis de la actividad antimalárica de los 4-Aminobiciclo[2.2.2] octan-2-il 4-aminobutanoatos y sus análogos etanoatos y propanoatos, usando la topología molecular para desarrollar un modelo de relación cuantitativa estructura-actividad QSAR. Mediante el empleo del análisis lineal discriminante se seleccionó una función capaz de clasificar correctamente 32 de 35 compuestos analizados según su actividad antimalárica. El modelo clasificó el 82,35 % de las moléculas consideradas activas de manera experimental y discriminó el 100 % de las moléculas inactivas como tales. Aplicando el análisis de regresión multilineal se seleccionó una función capaz de predecir la actividad antimalárica de cada compuesto en términos de pIC 50. Para la validación del modelo se emplearon la técnica de validación cruzada y un test de aleatoriedad. Tras este análisis, se han propuesto nuevas estructuras antimaláricas potencialmente activas.Malaria causes one of the highest mortality rates worldwide. Malaria cases and malaria deaths are still increasing due to, among other factors, the resistance that the parasite has developed to treatments. New molecules have been analyzed to be used as treatment for this disease. The present study predicts the antiplasmodial activity of the Aminobicyclo[2.2.2]octan-2-yl 4-aminobutanoates and their equivalents ethanoates and propanoates using molecular topology to develop a quantitative structure-activity relation (QSAR) model. Linear discriminant analysis was used to find a mathematical statement able to classify 32 of 35 compounds accurately by their antiplasmodial activity. The model classified 82.35 % of molecules considered active with experimental methods, and differentiated 100 % of the inactive molecules as such. Multilinear regression analysis was applied to find an equation with the ability to predict the antiplasmodial activity of each compound in terms of pIC50. Crossvalidation and randomness tests were carried out to validate this model. Finally, new potential antiplasmodial molecules have been proposed.Ciencias Experimentale

A double-sided, shield-less stave prototype for the ATLAS upgrade strip tracker for the high luminosity LHC

A detailed description of the integration structures for the barrel region of the silicon strips tracker of the ATLAS Phase-II upgrade for the upgrade of the Large Hadron Collider, the so-called High Luminosity LHC (HL-LHC), is presented. This paper focuses on one of the latest demonstrator prototypes recently assembled, with numerous unique features. It consists of a shortened, shield-less, and double sided stave, with two candidate power distributions implemented. Thermal and electrical performances of the prototype are presented, as well as a description of the assembly procedures and tools

Invasion biology in non-free-living species: interactions between abiotic (climatic) and biotic (host availability) factors in geographical space in crayfish commensals (Ostracoda, Entocytheridae)

In invasion processes, both abiotic and biotic factors are considered essential, but the latter are usually disregarded when modeling the potential spread of exotic species. In the framework of set theory, interactions between biotic (B), abiotic (A), and movement-related (M) factors in the geographical space can be hypothesized with BAM diagrams and tested using ecological niche models (ENMs) to estimate A and B areas. The main aim of our survey was to evaluate the interactions between abiotic (climatic) and biotic (host availability) factors in geographical space for exotic symbionts (i.e., non-free-living species), using ENM techniques combined with a BAM framework and using exotic Entocytheridae (Ostracoda) found in Europe as model organisms. We carried out an extensive survey to evaluate the distribution of entocytherids hosted by crayfish in Europe by checking 94 European localities and 12 crayfish species. Both exotic entocytherid species found, Ankylocythere sinuosa and Uncinocythere occidentalis, were widely distributed in W Europe living on the exotic crayfish species Procambarus clarkii and Pacifastacus leniusculus, respectively. No entocytherids were observed in the remaining crayfish species. The suitable area for A. sinuosa was mainly restricted by its own limitations to minimum temperatures in W and N Europe and precipitation seasonality in circum-Mediterranean areas. Uncinocythere occidentalis was mostly restricted by host availability in circum-Mediterranean regions due to limitations of P. leniusculus to higher precipitation seasonality and maximum temperatures. The combination of ENMs with set theory allows studying the invasive biology of symbionts and provides clues about biogeographic barriers due to abiotic or biotic factors limiting the expansion of the symbiont in different regions of the invasive range. The relative importance of abiotic and biotic factors on geographical space can then be assessed and applied in conservation plans. This approach can also be implemented in other systems where the target species is closely interacting with other taxa

Leptonic CP Violation and Neutrino Mass Models

We discuss leptonic mixing and CP violation at low and high energies, emphasizing possible connections between leptogenesis and CP violation at low energies, in the context of lepton flavour models. Furthermore we analyse weak basis invariants relevant for leptogenesis and for CP violation at low energies. These invariants have the advantage of providing a simple test of the CP properties of any lepton flavour model.Comment: 26 pages, no figures, submitted to the Focus Issue on `Neutrino Physics` edited by F. Halzen, M. Lindner and A. Suzuki, to be published in New Journal of Physic