“ROC” Chips Readout

International audienceThe OMEGA group at LAL has designed 3 chips for ILC calorimeters: one analog (SPIROC) and one digital (HARDROC) for the hadronic one and also one for the electromagnetic one (SKIROC). The readout and the management of these different chips will be explained. To minimize the lines between the ASICs and the DAQ, the readout is made thanks to 2 lines which are common for all the chips: Data and TransmitOn. As the chips are daisy chained, each chip is talking to the DAQ one after the other. When one chip has finished its readout, it starts the readout of the chip just after. Moreover, during this readout, only the chip which is talking to the DAQ is powered: this is made thanks to the POD (Power On Digital) module in the ASIC. In the ILC mode, readout sequence is active during inter bunch crossing (like ADC conversion). Another chip designed for PMM2 R&D program (PARISROC) integrates a new selective readout: that's mean only hit channels are sent to the DAQ in a complete autonomous mode

Bioaccumulation d'aluminium chez la truite Salmo truffa fario soumise au retombées des pluies acides : étude structurale, ultrastructurale et microanalytique

Des études microanalytiques ont été menées sur des truites Salmo trutta fario, âgées de deux ans, récoltées dans une rivière des Vosges soumise aux retombées des pluies acides et sur des truites témoins récoltées dans une rivière d'Auvergne, non soumise aux pluies acides. La rivière des Vosges est caractérisée par un pH de 5,42 et par une concentration en aluminium de 200 µg/L-1. Notre but étant de déterminer les tissus, cellules et organites cibles de bioaccumulation éventuelle de l'aluminium, nous avons analysé rein, foie, branchie et tractus digestif. Deux méthodes microanalytiques ont été utilisées pour localiser l'aluminium à l'échelle cellulaire et subcellulaire et connaître les éléments avec lesquels il peut être associé; ce sont la spectrométrie de masse par émission ionique secondaire (microscope ionique associé à un système informatisé de traitement d'images) et la spectrométrie des rayons X (microsonde électronique de Castaing associée à un microscope électronique à transmission).La microanalyse des rein, foie, branchie et tractus digestif montre l'existence de deux processus conduisant à la bioaccumulation de l'aluminium. Le premier, classiquement connu pour d'autres métaux, met en évidence une insolubilisation de l'aluminium sous forme de phosphate, dans des organites limités par une membrane : les lysosomes et les granules pigmentaires des mélanocytes. Le second, démontre la formation de volumineux dépots extra-cellulaires, atteignant 100 µm de long et entraînant la destruction du tissu. Aucune bioaccumulation significative d'aluminium n'a été observée chez des truites témoins, récoltées dans le centre de la France, où l'eau à pH 7.9 est dépourvue d'aluminium.The major harm caused by acidic precipitation is shown by a disappearance of fish. Other factors besides acidity such as aluminium levels are significantly harmful and many studies have shown that aluminium ions are toxic to fish. The only sensible course of action is to investigate the basic mechanisms by which each of the metal pollutants enters and attacks living systems. For this, one needs to be a combination of physicist, chemist, biochemist, physiologist and toxicologist. Investigations on metal bioaccumulation require very sensitive analytical instrumentation. Total analytical methods commonly used are inadequate : absorbed and adsorbed elements cannot be distinguished.Therefore, interesting information can be obtained by using physical methods of chemical microanalysis : two available microanalytical techniques are particularly suitable, X-ray spectrometry and secondary ion mass spectrometry.X-ray spectrometry, also called Electron Probe X-ray Microanalysis or Electron Microprobe (EMP) provides a means for studying the local chemical composition and structure of biological specimens. EMP can be used in association with a photon microscope or with a transmission electron microscope allowing the detection of elements at subcellular level.The Secondary Ion Mass Spectrometry (SIMS), also called Ion Microscopy, allows to visualize, analyse and photograph the microscopical distribution of the stable or radioactive isotopes of the elements present in a histological section. The sensitivity of the method is very high, ranging from 0.1 to 1 ppm. In association with SIMS, a processing of secondary ion images is used.Two years-old samples of Salmo trutta fario, from wild populations living in acidified waters of Eastern France (near Cornimont in the Vosges moutains) were studied for aluminium detection at cellular and subcellular levels. The acidified waters were characterized by a low pH (5,42) and high aluminium level reaching 200 µg/L-1. Control trouts living in non acidified waters (pH : 7.9 and aluminium free) of central France (near Clermont-Ferrand) were used for comparison. In order top determine the tissues, cells and organelles of a possible aluminium concentration, the following organs were investigated : kidney, liver, gill and digestive tractus, using both microanalytical techniques described above.In the kidney ion images showed aluminium emission from tubule lysosomes with a ring-shaped localization along the apical border of the epithetial cells; aluminium emissions from the tubule lumen and from the pigment granules of the melanocytes were also observed. Using the electron microprobe, X-ray emission spectra of aluminium associated with phosphorus were obtained from lysosomes and pigment granules. In the liver and in the gills, ion images showed a high aluminium emission from the same organelles and X-ray spectra of aluminium and phosphorus were also obtained. Moreover, in the pyloric caeca, large extracellular deposits of aluminium were detected : they measured about 100 µm in length and were located in places where tissues had been destroyed.The same structural, ultrastructural and microanalytical investigations were performed on the control trouts from which non aluminium detection was obtained.In conclusion, two processes appear to be involved in the aluminium accumulation in the brown trout. The first one corresponds to a well known insolubilisation of aluminium phosphate inside the lysosomes, due to an acidic phosphatase enzymatic activity; aluminium is also trapped inside pigment granules. Both of these mechanisms of storage inside membrane-limited organelles, prevent cells from any interior damage. The second one corresponds to the formation of large extracellular deposits which are likely to provoke injuries leading to the tissue destruction. Such data demonstrating basic mechanisms of aluminium accumulation in a fish, could not have been obtained using total analytical methods

PARISROC, a Photomultiplier Array Integrated Read Out Chip

PARISROC is a complete read out chip, in AMS SiGe 0.35 !m technology, for photomultipliers array. It allows triggerless acquisition for next generation neutrino experiments and it belongs to an R&D program funded by the French national agency for research (ANR) called PMm2: ?Innovative electronics for photodetectors array used in High Energy Physics and Astroparticles? (ref.ANR-06-BLAN-0186). The ASIC (Application Specific Integrated Circuit) integrates 16 independent and auto triggered channels with variable gain and provides charge and time measurement by a Wilkinson ADC (Analog to Digital Converter) and a 24-bit Counter. The charge measurement should be performed from 1 up to 300 photo- electrons (p.e.) with a good linearity. The time measurement allowed to a coarse time with a 24-bit counter at 10 MHz and a fine time on a 100ns ramp to achieve a resolution of 1 ns. The ASIC sends out only the relevant data through network cables to the central data storage. This paper describes the front-end electronics ASIC called PARISROC.Comment: IEEE Nuclear Science Symposium an Medical Imaging Conference (2009 NSS/MIC

Front-end Electronic for the Calice ECAL Physics Prototype

eConf: C050318 : 0902A 18-channel low-noise front-end chip has been designed and produced to read out the 1cm² silicon PIN diodes of the CALICE WSi physics prototype calorimeter. Each channel includes a multi-gain low noise charge preamplifier followed by a bi-gain shaper and a track and hold device. A single output allows reading out every channel at 5 MHz through a multiplexer. Voltage swing is 2.5V with a 5‰ non-linearity. The measured dynamic range on a fixed gain is larger than 13 bits. The gain of the preamplifier can be tuned from 0.3V/pC to 5V/pC with 4 bits. The shaping is done by two fixed-gain shapers (gain 1 and gain 10). Output measured noise is 3000 e- with a detector capacitance of 100pF and a MIP around 42000 e-. Crosstalk is around 1‰. 1000 chips have been produced to equip the physics prototype. Several version of PCB have been designed, taking into account the thickness constraint. A first version with the front-end chip outside the detector has been produced and has been running since January 2005 at DESY, exhibiting an overall MIP/noise ratio of 9. A new thinner version embedding the chip inside the calorimeter has been prototyped and is ready to go in test beam

Set up of a new in vitro model to study dietary fructans fermentation in formula-fed babies

A new in vitro fermentation model with immobilised infant faecal microbiota simulating the proximal colon of a formula-fed baby was developed and used to test the effects of known prebiotic fructans. Intestinal fermentation, based on a previously developed colonic fermentation model, using a new feeding medium simulating a formula-fed infant ileal chyme, was carried out for seventy-one consecutive days divided into four stabilisation periods intercalated with four prebiotic treatment periods. At the end of the first stabilisation period, total bacterial concentration in colonised beads and in faecal sample was similar, metabolite concentrations returned to stabilisation values after each treatment period. As expected, the four prebiotic treatments significantly increased the bifidobacterial populations, whereas they decreased bacteroides and clostridia. No difference was observed in the prebiotic effect of these substrates selected. The treatments significantly increased total production of SCFA and decreased ammonia compared to stabilisation periods. Long-term stability of the system together with the reproducibility of the known prebiotic effects highlights the potential of the present model to quantify and compare the effects of different substrates in a formula-fed infant microbiota within the same fermentation experimen

Protective effect of probiotics on Salmonella infectivity assessed with combined in vitro gut fermentation-cellular models

<p>Abstract</p> <p>Background</p> <p>Accurate assessment of probiotics with targeted anti-<it>Salmonella </it>activity requires suitable models accounting for both, microbe-microbe and host-microbe interactions in gut environments. Here we report the combination of two original <it>in vitro </it>intestinal models closely mimicking the complex <it>in vivo </it>conditions of the large intestine. Effluents from continuous <it>in vitro </it>three-stage fermentation colonic models of <it>Salmonella </it>Typhimurium infection inoculated with immobilized child microbiota and <it>Salmonella </it>were directly applied to confluent mucus-secreting HT29-MTX cell layers. The effects of <it>Salmonella</it>, addition of two bacteriocinogenic strains, <it>Bifidobacterium thermophilum </it>RBL67 (thermophilicin B67) and <it>Escherichia coli </it>L1000 (microcin B17), and inulin were tested on <it>Salmonella </it>growth and interactions with epithelial cell layers. <it>Salmonella </it>adhesion and invasion were investigated and epithelial integrity assessed by transepithelial electrical resistance (TER) measurements and confocal microscopy observation. Data from complex effluents were compared with pure <it>Salmonella </it>cultures.</p> <p>Results</p> <p><it>Salmonella </it>in effluents of all reactors of the colonic fermentation model stabilized at mean values of 5.3 ± 0.8 log₁₀cfu/ml effluent. Invasion of cell-associated <it>Salmonella </it>was up to 50-fold lower in complex reactor samples compared to pure <it>Salmonella </it>cultures. It further depended on environmental factors, with 0.2 ± 0.1% being measured with proximal, 0.6 ± 0.2% with transverse and 1.3 ± 0.7% with distal reactor effluents, accompanied by a similar high decrease of TER across cell monolayers (minus 45%) and disruption of tight junctions. Subsequent addition of <it>E. coli </it>L1000 stimulated <it>Salmonella </it>growth (6.4 ± 0.6 log₁₀cfu/ml effluent of all 3 reactors) and further decreased TER, but led to 10-fold decreased invasion efficiency when tested with distal reactor samples. In contrast, presence of <it>B. thermophilum </it>RBL67 revealed a protective effect on epithelial integrity compared to previous <it>E. coli </it>L1000 periods, as reflected by a significant mean increase of TER by 58% in all reactors. Inulin addition enhanced <it>Salmonella </it>growth and invasion when tested with distal and proximal reactor samples, respectively, but induced a limited decrease of TER (minus 18%) in all reactors.</p> <p>Conclusions</p> <p>Our results highlight the benefits of combining suitable cellular and colonic fermentation models to assess strain-specific first-level host protection properties of probiotics during <it>Salmonella </it>infection, providing an efficient system biology tool for preclinical development of new antimicrobials.</p

The composition and metabolic activity of child gut microbiota demonstrate differential adaptation to varied nutrient loads in an in vitro model of colonic fermentation

The extent to which the dietary loads of simple sugars, carbohydrates, protein, and fiber impact colonic fermentation in children is unknown. This study assessed the impact of dietary energy on gut microbial communities and metabolism using a three-stage in vitro continuous fermentation model. Two separate models, replicating the proximal, transverse, and distal colon regions, were inoculated with immobilized fecal microbiota from one of two female children. Three different fermentation media were designed to examine the effects of prevalent Western dietary trends on gut microbiota. Media compositions reflected obese (high energy), normal weight (normal energy), and anorectic (low energy) child dietary intakes and were alternately supplied to each microbiota during separate fermentation periods. Gut microbiota demonstrated differential metabolic and compositional adaptation to varied substrate availability. High energy medium was strongly butyrogenic, resulting in significant stimulation of butyrate-producing members of clostridia cluster XIVa, whereas members of cluster IV demonstrated greater adaptive variability. Normal and low energy nutrient loads induced significantly less metabolic activity in both microbiota, with low energy medium inducing a broad reorganization of the commensal community structure. These results suggest a concerted metabolic adaptation in response to nutrient load, exercised by different microbial populations, indicating substantial redundancy in gastrointestinal metabolic pathway

FLC−SIPM: Front-End Chip for SIPM Readout for ILC Analog HCAL

eConf: C050318 : LCWS-2005-0916An integrated front-end chip has been developed to readout the Silicon PM for the ILC analog hadronic calorimeter. It is built around a variable gain low-noise preamplifier followed by a variable peaking-time shaper (20-200 ns), track and hold and multiplexed output. This structure allows to produce single photo electron spectrum with well separated peaks for absolute calibration at fast shaping (40ns) as well as physics signals from the scintillating fibbers (up to 2000 photo-electrons) with a slower shaping (150ns) compatible with the W-Si Electromagnetic Calorimeter DAQ. Besides, an input DAC allows to tune the detector gain by varying the operating voltage by up to 5V. The chip accommodates 18 channels and 1000 circuits have been produced in 2004, the design and the measurement results of which will be presented

Design and Measurement of Integrated Converters for Belt-driven Starter-generator in 48 V Micro/mild Hybrid Vehicles

With reference to a 48 V belt-driven starter-generator, used in micro/mild hybrid vehicles, the paper shows the design and measurement of an integrated H-bridge and of a compact DC/DC converter, both fabricated in low-cost HV-MOS technology. The H-bridge is in charge of rotor excitation and, thanks to a direct copper bonding of the HV-MOS devices on a ceramic substrate, it ensures a full-integrated solution with low ON-resistance values. The compact DC/DC converter interfaces the 48 V power domain with the lower voltage domain of sensing and control electronics, such as 5 V and 1.65 V in this case study, without using cumbersome inductors and transformers. The latter are difficult to integrate in silicon technology. The converter has a multi stage architecture, where each stage implements a switched capacitor regulation. Multiple voltage outputs are supported, with a configurable regulation factor, sustaining an input voltage variation from 6 V (in case of cranking) up to 60 V. Specific design techniques have been implemented to reduce electromagnetic interference (EMI), typical of switching converters. Experimental measurements on fabricated prototype chipsets confirm the suitability of the presented designs for low-EMI 48 V application

Low iron availability in continuous in vitro colonic fermentations induces strong dysbiosis of the child gut microbial consortium and a decrease in main metabolites

Iron (Fe) deficiency affects an estimated 2 billion people worldwide, and Fe supplements are a common corrective strategy. The impact of Fe deficiency and Fe supplementation on the complex microbial community of the child gut was studied using in vitro colonic fermentation models inoculated with immobilized fecal microbiota. Chyme media (all Fe chelated by 2,2′-dipyridyl to 26.5 mg Fe L−1) mimicking Fe deficiency and supplementation were continuously fermented. Fermentation effluent samples were analyzed daily on the microbial composition and metabolites by quantitative PCR, 16S rRNA gene 454-pyrosequencing, and HPLC. Low Fe conditions (1.56 mg Fe L−1) significantly decreased acetate concentrations, and subsequent Fe supplementation (26.5 mg Fe L−1) restored acetate production. High Fe following normal Fe conditions had no impact on the gut microbiota composition and metabolic activity. During very low Fe conditions (0.9 mg Fe L−1 or Fe chelated by 2,2′-dipyridyl), a decrease in Roseburia spp./Eubacterium rectale, Clostridium Cluster IV members and Bacteroides spp. was observed, while Lactobacillus spp. and Enterobacteriaceae increased consistent with a decrease in butyrate (−84%) and propionate (−55%). The strong dysbiosis of the gut microbiota together with decrease in main gut microbiota metabolites observed with very low iron conditions could weaken the barrier effect of the microbiota and negatively impact gut healt