The ALICE Silicon Pixel Detector Control system and online calibration tools

The ALICE Silicon Pixel Detector (SPD) contains nearly 107 hybrid pixel cells. The operation of the SPD requires online control and monitoring of some 2000 parameters and » 50000DACs. Information for each channel is stored in a configuration database. Timing and data management (» 6GB of raw data each calibration) are critical issues. An overview of the SPD electronics read out chain and of the detector control system is given with a detailed description of the front-end controls and the calibration strategy. The status of commissioning and a preliminary evaluation of detector performance are presented

Beam Test Performance and Simulation of Prototypes for the ALICE Silicon Pixel Detector

The silicon pixel detector (SPD) of the ALICE experiment in preparation at the Large Hadron Collider (LHC) at CERN is designed to provide the precise vertex reconstruction needed for measuring heavy flavor production in heavy ion collisions at very high energies and high multiplicity. The SPD forms the innermost part of the Inner Tracking System (ITS) which also includes silicon drift and silicon strip detectors. Single assembly prototypes of the ALICE SPD have been tested at the CERN SPS using high energy proton/pion beams in 2002 and 2003. We report on the experimental determination of the spatial precision. We also report on the first combined beam test with prototypes of the other ITS silicon detector technologies at the CERN SPS in November 2004. The issue of SPD simulation is briefly discussed.Comment: 4 pages, 5 figures, prepared for proceedings of 7th International Position Sensitive Detectors Conference, Liverpool, Sept. 200

The ALICE silicon pixel detector read-out electronics

The ALICE silicon pixel detector (SPD) constitutes the two innermost layers of the ALICE inner tracker system. The SPD contains 10 million pixels segmented in 120 detector modules (half staves), which are connected to the offdetector electronics with bidirectional optical links. Raw data from the on-detector electronics are sent to 20 FPGA-based processor cards (Routers) each carrying three 2-channel linkreceiver daughter-cards. The routers process the data and send them to the ALICE DAQ system via the ALICE detector data link (DDL). The SPD control, configuration and data monitoring is performed via the VME interface of the routers. This paper describes the detector readout and control via the off-detector electronics

Diverse effects of natural and synthetic surfactants on the inhibition of staphylococcus aureus biofilm

A major challenge in the biomedical field is the creation of materials and coating strategies that effectively limit the onset of biofilm-associated infections on medical devices. Biosurfactants are well known and appreciated for their antimicrobial/anti-adhesive/anti-biofilm properties, low toxicity, and biocompatibility. In this study, the rhamnolipid produced by Pseudomonas aeruginosa 89 (R89BS) was characterized by HPLC-MS/MS and its ability to modify cell surface hydrophobicity and membrane permeability as well as its antimicrobial, anti-adhesive, and anti-biofilm activity against Staphylococcus aureus were compared to two commonly used surfactants of synthetic origin: Tween® 80 and Triton™ X-100. The R89BS crude extract showed a grade of purity of 91.4% and was composed by 70.6% of mono-rhamnolipids and 20.8% of di-rhamnolipids. The biological activities of R89BS towards S. aureus were higher than those of the two synthetic surfactants. In particular, the anti-adhesive and anti-biofilm properties of R89BS and of its purified mono-and di-congeners were similar. R89BS inhibition of S. aureus adhesion and biofilm formation was ~97% and 85%, respectively, and resulted in an increased inhibition of about 33% after 6 h and of about 39% after 72 h when compared to their chemical counterparts. These results suggest a possible applicability of R89BS as a protective coating agent to limit implant colonization

La cooperación en la industria vitivinícola : Contribución para resolver la crisis vitivinícola nacional

En el trabajo de tesis, cuyo resumen se publica, el autor hace algunas referencias sobre la introducción de la vid en América del Sur y posteriormente en la Argentina. Analiza las crisis que ha soportado la industria vitivinícola y hace una comparación entre ellas. Llega en su estudio a determinar que, para lograr la estabilización definitiva del mercado de vinos, es necesario modificar la estructuración sobre la que está montadla actualmente, no solo en su faz industrial sino también comercial, recalcando que la solución no podrá lograrse sin suprimir la coexistencia de gremios con intereses distintos y opuestos, como son los que representan a los vinateros sin bodegas y bodegueros trasladistas por una parte y a las grandes bodegas por otra; reconociendo que, si bien los primeros están expuestos a la especulación de los grandes establecimientos, su permanencia como tales, ocasiona en contra de sus intereses, serios trastornos a la industria impidiendo la regulación definitiva de la misma.Facultad de Ciencias Agrarias y Forestale

Performance of ALICE pixel prototypes in high energy beams

The two innermost layers of the ALICE inner tracking system are instrumented with silicon pixel detectors. Single chip assembly prototypes of the ALICE pixels have been tested in high energy particle beams at the CERN SPS. Detection efficiency and spatial precision have been studied as a function of the threshold and the track incidence angle. The experimental method, data analysis and main results are presented.Comment: 10 pages, 9 figures, contribution to PIX2005 Workshop, Bonn (Germany), 5-8 September 200

La cooperación en la industria vitivinícola : Contribución para resolver la crisis vitivinícola nacional

En el trabajo de tesis, cuyo resumen se publica, el autor hace algunas referencias sobre la introducción de la vid en América del Sur y posteriormente en la Argentina. Analiza las crisis que ha soportado la industria vitivinícola y hace una comparación entre ellas. Llega en su estudio a determinar que, para lograr la estabilización definitiva del mercado de vinos, es necesario modificar la estructuración sobre la que está montadla actualmente, no solo en su faz industrial sino también comercial, recalcando que la solución no podrá lograrse sin suprimir la coexistencia de gremios con intereses distintos y opuestos, como son los que representan a los vinateros sin bodegas y bodegueros trasladistas por una parte y a las grandes bodegas por otra; reconociendo que, si bien los primeros están expuestos a la especulación de los grandes establecimientos, su permanencia como tales, ocasiona en contra de sus intereses, serios trastornos a la industria impidiendo la regulación definitiva de la misma.Facultad de Ciencias Agrarias y Forestale

Examining the effects of sodium ions on the binding of antagonists to dopamine D2 and D3 receptors

Many G protein-coupled receptors have been shown to be sensitive to the presence of sodium ions (Na+). Using radioligand competition binding assays, we have examined and compared the effects of sodium ions on the binding affinities of a number of structurally diverse ligands at human dopamine D2 and dopamine D3 receptor subtypes, which are important therapeutic targets for the treatment of psychotic disorders. At both receptors, the binding affinities of the antagonists/inverse agonists SB-277011-A, L,741,626, GR 103691 and U 99194 were higher in the presence of sodium ions compared to those measured in the presence of the organic cation, N-methyl-D-glucamine, used to control for ionic strength. Conversely, the affinities of spiperone and (+)-butaclamol were unaffected by the presence of sodium ions. Interestingly, the binding of the antagonist/inverse agonist clozapine was affected by changes in ionic strength of the buffer used rather than the presence of specific cations. Similar sensitivities to sodium ions were seen at both receptors, suggesting parallel effects of sodium ion interactions on receptor conformation. However, no clear correlation between ligand characteristics, such as subtype selectivity, and sodium ion sensitivity were observed. Therefore, the properties which determine this sensitivity remain unclear. However these findings do highlight the importance of careful consideration of assay buffer composition for in vitro assays and when comparing data from different studies, and may indicate a further level of control for ligand binding in vivo

The effect of sophorolipids against microbial biofilms on medical-grade silicone

Recent medical strategies rely on the search for effective antimicrobials as surface coatings to prevent and treat infections in humans and animals. Biosurfactants have recently been shown to have properties as antiadhesive and antibiofilm agents. Sophorolipids in particular are biosurfactant molecules known to act as therapeutic agents. This study aimed to evaluate antimicrobial properties of sophorolipids in medical-grade silicone discs using strains of clinical relevance. Sophorolipids were produced under fed batch conditions, ESI-MS analyses were carried out to confirm the congeners present in each formulation. Three different products were obtained SLA (acidic congeners), SL18 (lactonic congeners) and SLV (mixture of acidic and lactonic congeners) and were tested against Staphylococcus aureus ATCC 6538, Pseudomonas aeruginosa ATCC 10145 and Candida albicans IHEM 2894. All three congener mixtures showed a biofilms disruption effect (> 0.1% w/v) of 70%, 75% and 80% for S. aureus, P. aeruginosa and C. albicans, respectively. On pre-coated silicone discs, biofilm formation of S. aureus was reduced by 75% using SLA 0.8% w/v. After 1.5 h the inhibition of C. albicans attachment was between 45-56% whilst after 24 h incubation the percentage of inhibition for the cell attachment increased to 68-70% when using SLA 0.8% w/v. Finally, in co-incubation experiments SLA 0.05% w/v significantly reduced the ability of S. aureus and C. albicans to form biofilms and to adhere to surfaces by 90-95% at concentrations between 0.025-0.1% w/v. In conclusion sophorolipids significantly reduced the cell attachment of both tested strains which suggests that these molecules could have a potential role as coating agents on medical grade silicone devices for the preventions of Gram positive bacteria and yeast infections

Potential of Manuka Honey as a Natural Polyelectrolyte to Develop Biomimetic Nanostructured Meshes With Antimicrobial Properties

The use of antibiotics has been the cornerstone to prevent bacterial infections; however, the emergency of antibiotic-resistant bacteria is still an open challenge. This work aimed to develop a delivery system for treating soft tissue infections for: (1) reducing the released antimicrobial amount, preventing drug-related systemic side effects; (2) rediscovering the beneficial effects of naturally derived agents; and (3) preserving the substrate functional properties. For the first time, Manuka honey (MH) was proposed as polyelectrolyte within the layer-by-layer assembly. Biomimetic electrospun poly(εcaprolactone) meshes were treated via layer-by-layer assembly to obtain a multilayered nanocoating, consisting of MH as polyanion and poly-(allylamine-hydrochloride) as polycation. Physicochemical characterization demonstrated the successful nanocoating formation. Different cell lines (human immortalized and primary skin fibroblasts, and primary endothelial cells) confirmed positively the membranes cytocompatibility, while bacterial tests using Gram-negative and Gram-positive bacteria demonstrated that the antimicrobial MH activity was dependent on the concentration used and strains tested