262 research outputs found
ATLAS Experiment Silicon Detector Alignment
ATLAS Experiment at the CERN's Large Hadron Collider is expected to start taking data at the end of 2007. The Atlas detector's tracking reconstruction is performed by drift tube and silicon based subdetectors. For the alignment of the silicon tracker, a combination of a hardware system and track based algorithms is planned to be used. In order to achieve the physics goals, ATLAS tracking requires that the position of the modules of the silicon tracker to be known with a precision better than about 10 microns. The whole silicon detector consists of a total of 5832 such modules with corresponding ~35000 degrees of freedom, therefore, obtaining the desired precision necessitates the design of non-trivial alignment strategies, and novel techniques both in hardware and software. We will first describe the Atlas inner detector and give the status of its commissioning. We will then introduce the proposed track based alignment algorithms for the silicon detector and their implementation into the ATLAS software framework, with more concentration given on one of the algorithms, which uses a global and simultaneous fit of all particle trajectories and alignment parameters. Performances and initial results from a combined test beam setup and from cosmic ray data taking will be discussed, where more emphasis will be given on the latter
Can bile duct injuries be prevented? "A new technique in laparoscopic cholecystectomy"
BACKGROUND: Over the last decade, laparoscopic cholecystectomy has gained worldwide acceptance and considered to be as "gold standard" in the surgical management of symptomatic cholecystolithiasis. However, the incidence of bile duct injury in laparoscopic cholecystectomy is still two times greater compared to classic open surgery. The development of bile duct injury may result in biliary cirrhosis and increase in mortality rates. The mostly blamed causitive factor is the misidentification of the anatomy, especially by a surgeon who is at the beginning of his learning curve. Biliary tree injuries may be decreased by direct coloration of the cystic duct, ductus choledochus and even the gall bladder. METHODS: gall bladder fundus was punctured by Veress needle and all the bile was aspirated. The same amount of fifty percent methylene blue diluted by saline solution was injected into the gall bladder for coloration of biliary tree. The dissection of Calot triangle was much more safely performed after obtention of coloration of the gall bladder, cystic duct and choledocus. RESULTS: Between October 2003 and December 2004, overall 46 patients (of which 9 males) with a mean age of 47 (between 24 and 74) underwent laparoscopic cholecystectomy with methylene blue injection technique. The diagnosis of chronic cholecystitis (the thickness of the gall bladder wall was normal) confirmed by pre-operative abdominal ultrasonography in all patients. The diameters of the stones were greater than 1 centimeter in 32 patients and calcula of various sizes being smaller than 1 cm. were documented in 13 cases. One patient was operated for gall bladder polyp (our first case). Successful coloration of the gall bladder, cystic duct and ductus choledochus was possible in 43 patients, whereas only the gall bladder and proximal cystic duct were visualised in 3 cases. In these cases, ductus choledochus visibility was not possible. None of the patients developed bile duct injury. CONCLUSION: The number of bile duct injuries related to anatomic misidentification can be decreased and even vanished by using intraoperative methylene blue injection technique into the gall bladder fundus intraoperatively
New Physics at the LHC. A Les Houches Report: Physics at TeV Colliders 2009 - New Physics Working Group
We present a collection of signatures for physics beyond the standard model
that need to be explored at the LHC. First, are presented various tools
developed to measure new particle masses in scenarios where all decays include
an unobservable particle. Second, various aspects of supersymmetric models are
discussed. Third, some signatures of models of strong electroweak symmetry are
discussed. In the fourth part, a special attention is devoted to high mass
resonances, as the ones appearing in models with warped extra dimensions.
Finally, prospects for models with a hidden sector/valley are presented. Our
report, which includes brief experimental and theoretical reviews as well as
original results, summarizes the activities of the "New Physics" working group
for the "Physics at TeV Colliders" workshop (Les Houches, France, 8-26 June,
2009).Comment: 189 page
Mapping interactions with the chaperone network reveals factors that protect against tau aggregation.
A network of molecular chaperones is known to bind proteins ('clients') and balance their folding, function and turnover. However, it is often unclear which chaperones are critical for selective recognition of individual clients. It is also not clear why these key chaperones might fail in protein-aggregation diseases. Here, we utilized human microtubule-associated protein tau (MAPT or tau) as a model client to survey interactions between ~30 purified chaperones and ~20 disease-associated tau variants (~600 combinations). From this large-scale analysis, we identified human DnaJA2 as an unexpected, but potent, inhibitor of tau aggregation. DnaJA2 levels were correlated with tau pathology in human brains, supporting the idea that it is an important regulator of tau homeostasis. Of note, we found that some disease-associated tau variants were relatively immune to interactions with chaperones, suggesting a model in which avoiding physical recognition by chaperone networks may contribute to disease
Combining functional weed ecology and crop stable isotope ratios to identify cultivation intensity: a comparison of cereal production regimes in Haute Provence, France and Asturias, Spain
This investigation combines two independent
methods of identifying crop growing conditions and husbandry
practices—functional weed ecology and crop stable
carbon and nitrogen isotope analysis—in order to assess
their potential for inferring the intensity of past cereal
production systems using archaeobotanical assemblages.
Present-day organic cereal farming in Haute Provence,
France features crop varieties adapted to low-nutrient soils
managed through crop rotation, with little to no manuring.
Weed quadrat survey of 60 crop field transects in this region
revealed that floristic variation primarily reflects
geographical differences. Functional ecological weed data
clearly distinguish the Provence fields from those surveyed
in a previous study of intensively managed spelt wheat in
Asturias, north-western Spain: as expected, weed ecological
data reflect higher soil fertility and disturbance in
Asturias. Similarly, crop stable nitrogen isotope values
distinguish between intensive manuring in Asturias and
long-term cultivation with minimal manuring in Haute
Provence. The new model of cereal cultivation intensity
based on weed ecology and crop isotope values in Haute
Provence and Asturias was tested through application to
two other present-day regimes, successfully identifying a
high-intensity regime in the Sighisoara region, Romania,
and low-intensity production in Kastamonu, Turkey. Application
of this new model to Neolithic archaeobotanical
assemblages in central Europe suggests that early farming
tended to be intensive, and likely incorporated manuring,
but also exhibited considerable variation, providing a finer
grained understanding of cultivation intensity than previously
available
Continuous Hydrothermal Co-liquefaction of Aspen Wood and Glycerol with Water Phase Recirculation
Component fractionation of wood-tar by column chromatography with the packing material of silica gel
New Physics at the LHC. A Les Houches Report: Physics at TeV Colliders 2009 - New Physics Working Group
We present a collection of signatures for physics beyond the standard model that need to be explored at the LHC. First, are presented various tools developed to measure new particle masses in scenarios where all decays include an unobservable particle. Second, various aspects of supersymmetric models are discussed. Third, some signatures of models of strong electroweak symmetry are discussed. In the fourth part, a special attention is devoted to high mass resonances, as the ones appearing in models with warped extra dimensions. Finally, prospects for models with a hidden sector/valley are presented. Our report, which includes brief experimental and theoretical reviews as well as original results, summarizes the activities of the "New Physics" working group for the "Physics at TeV Colliders" workshop (Les Houches, France, 8-26 June, 2009)
Heterogeneously catalyzed lignin depolymerization
Biomass offers a unique resource for the sustainable production of bio-derived chemical and fuels as drop-in replacements for the current fossil fuel products. Lignin represents a major component of lignocellulosic biomass, but is particularly recalcitrant for valorization by existing chemical technologies due to its complex cross-linking polymeric network. Here, we highlight a range of catalytic approaches to lignin depolymerisation for the production of aromatic bio-oil and monomeric oxygenates
Abstracts of presentations on plant protection issues at the fifth international Mango Symposium Abstracts of presentations on plant protection issues at the Xth international congress of Virology: September 1-6, 1996 Dan Panorama Hotel, Tel Aviv, Israel August 11-16, 1996 Binyanei haoma, Jerusalem, Israel
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