Abstract
The high luminosity expected from the HL-LHC will provide a great opportunity for precise physics measurements and searches for new physics. Nevertheless, the increased rate of particles ...coming from the collisions will pose a challenge for the CMS detectors. To prepare the muon system for the challenging conditions during the high luminosity phase, several upgrades have been planned and are being developed. Thanks to their fast time and space resolution, resistive plate chambers form part of the trigger system and are installed both in the barrel and endcap regions as a subsystem of the muon detector. As part of the upgrades, the muon forward region will be enhanced with two stations, called RE3/1 and RE4/1, equipped with improved Resistive Plate Chambers (iRPCs). These detectors use thinner electrodes, a narrower gas gap (1.4 mm compared to 2 mm in the current design) and improved front-end electronics. These features allow them to withstand particle rates up to a few kHz/cm
2
. Furthermore, they will extend the geometrical acceptance of the RPCs from a pseudorapidity of 1.9 to 2.4. In this work we present different studies related to the iRPC prototypes in preparation for the high luminosity phase of the LHC.
Multigap Resistive Plate Chambers (MRPCs) are often used as time-of-flight (TOF) detectors for high-energy physics and nuclear experiments thanks to their excellent time accuracy. For the Compressed ...Baryonic Matter (CBM) TOF system, MRPCs are required to work at particle fluxes on the order of 1–10kHz/cm2 for the outer region and 10–25kHz/cm2 for the central region. Better time resolution will allow particle identification with TOF techniques to be performed at higher momenta. From our previous studies, a time resolution of 25ps has been obtained with a 20-gap MRPC of 140μm gap size with enhanced rate capability. By using a new type of commercially available thin low-resistivity glass, further improvement MRPC rate capability is possible. In order to study the rate capability of the 10-gap MRPC built with this new low-resistivity glass, we have performed tests using the continuous electron beam at ELBE. This 10-gap MRPC, with 160μm gaps, reaches 97% efficiency at 19.2kV and a time resolution of 36ps at particle fluxes near 2kHz/cm2. At a flux of 100kHz/cm2, the efficiency is still above 95% and a time resolution of 50ps is obtained, which would fulfil the requirement of CBM TOF system.
Objetivo Caracterizar los hogares colombianos en inseguridad alimentaria segun calidad de vida. Materiales y metodos Para determinar la calidad de vida de los hogares colombianos se empleo la base de ...datos de la Encuesta de Calidad de Vida realizada en el ano 2008 por el Departamento Nacional de Estadisticas de Colombia. Para establecer las prevalencias de inseguridad alimentaria en el hogar (INSAH) se utilizo la Escala Latinoamericana y Caribena para la medicion de la Seguridad Alimentaria en el Hogar, adaptada y validada para Colombia. Los datos se analizaron con la prueba Chi cuadrado y mediante un analisis de regresion logistica. Resultados En los hogares donde se hallo mayor probabilidad de inseguridad alimentaria, fue en aquellos con casa propia pero que la estaban pagando o los que tenian posesion de la vivienda pero sin titulo, los que manifestaron que los ingresos solo alcanzaban para cubrir los gastos minimos y en los que no alcanzan para cubrir los gastos minimos, en los que manifestaron sentirse pobres y en los que vivian hacinados. Perder el empleo por parte del jefe del hogar, atrasarse en el pago de los servicios publicos 4 meses o mas, disminuir el gasto en alimentacion y haberse gastado los ahorros, tambien incremento esta probabilidad. Conclusion La INSAH se asocio de forma significativa con condiciones socioeconomicas del hogar y del jefe del hogar. Palabras Clave: Seguridad alimentaria, hambre, calidad de vida, pobreza, Colombia (fuente: DeCS, BIREME). Objective Characterizing Colombian households regarding quality of life-based food insecurity. Materials and Methods Colombian households' quality of life was determined using data from the quality of life survey carried out by the Colombian Statistics' Department in 2008. The Latin-American and Caribbean Household Food Insecurity Scale was used for measuring the prevalence of household food insecurity(after having been adapted and validated for Colombia). Data was analyzed using the Chi square test and logistic regression analysis. Results The households having a higher probability of food insecurity were those owning their dwelling but still paying the mortgage or those who were in possession of a dwelling without ownership documents, households where income was deemed insufficient for covering minimum expenses or did not cover minimum expenses, those who stated that they felt poor and those living in overcrowded conditions. The probability of food insecurity was also increased in households where the head of the family had lost her/his job, where late payments of 4 months or more were due for public utilities, had decreased food expenses or had spent their savings. Conclusion Household food Insecurity was significantly associated with a household's socioeconomic conditions and those of a head of household. Key Words: Hunger, quality of life, household, poverty, Colombia (source: MeSH, NLM).
Neutrophils are one the earliest, crucial innate defenses against innumerable pathogens. Their main microbicidal activities include phagocytosis and degranulation, with many pharmacologically active ...molecules contributing to inflammation. Recently, a novel antimicrobial mechanism was discovered; the Neutrophil Extracelullar Traps (NETs) formed by extrusion of DNA and associated molecules (histones, elastase, antimicrobial peptides, among others) which trap and kill microorganisms. Since NETs were recently described, research has focused on their induction and microbicidal properties, and recently on disease involvement. However, the functional consequences of NETs interacting with other immune cells, either resident or recruited during early inflammation, have not been assessed.
We therefore investigated the consequences of exposing two major APCs, macrophages (Mfs) and conventional Dendritic Cells (cDCs) to NETs. Our data revealed that at early times (30 min), both Antigen Presenting Cells (APCs) showed induction of important costimulatory molecules (CD80, CD86). Unexpectedly, however, at later times (6 and 24 hours) NETs apparently triggered a cell death process in these APCs by a caspase- and Apoptosis induced factor (AIF)-dependent pathway, suggesting mitochondrial damage. By rhodamine-123 labelling we found that in both APCs, relatively prolonged exposure to NETs or their components importantly decreased the mitochondrial membrane potential. Ultrastructural analysis confirmed mitochondrial alterations in both APCs.
Our results would suggest that early in inflammation, NETs can activate the two main APCs (Mfs and cDCs), but as the process continues, NETs can then initiate apoptosis of these cells through mitochondrial harm. Conceivable, this “late” induction of cell death in these two APCs might start limiting an ongoing inflammatory process to control it.
Based on previous experience and attempt, a real-size mosaic Multi-gap Resistive Plate Chamber (MRPC) has been developed within the framework of the CMS muon upgrade efforts. The chamber is a 5-gap ...with plates made each of 6 pieces of low resistive glass. Cosmic ray test at CERN 904 shows that its efficiency can reach above 95% with a gas mixture of 90% C2H2F4, 5% i-C4H10 and 5% SF6. The chamber was also tested with CMS dry gas(95.2% C2H2F4, 4.5% i-C4H10, 0.3% SF6) at the CERN Gamma Irradiation Facility (GIF++). Efficiency results calculated by a simple tracking method show that the good performance is maintained at rates up to 10 kHz/cm2.
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