227 research outputs found
NAUTILUS and EXPLORER: Present status and recent data analysis
This paper describes the present status of the two detectors
NAUTILUS and EXPLORER, the most sensitive resonant gravitational-wave antennas nowadays working in the world, and reports the results from the recent data analysis
Genomic analysis of three cheese-borne pseudomonas lactis with biofilm and spoilage-associated behavior
Psychrotrophic pseudomonads cause spoilage of cold fresh cheeses and their shelf-life reduction. Three cheese-borne Pseudomonas sp., ITEM 17295, ITEM 17298, and ITEM 17299 strains, previously isolated from mozzarella cheese, revealed distinctive spoilage traits based on molecular determinants requiring further investigations. Genomic indexes (ANI, isDDH), MLST-based phylogeny of four housekeeping genes (16S rRNA, gyrB, rpoB and rpoD) and genome-based phylogeny reclassified them as Pseudomonas lactis. Each strain showed distinctive phenotypic traits at 15 and 30â—¦C: ITEM 17298 was the highest biofilm producer at both temperatures, whilst ITEM 17295 and ITEM 17299 showed the strongest proteolytic activity at 30â—¦C. A wider pattern of pigments was found for ITEM 17298, while ITEM 17295 colonies were not pigmented. Although the high genomic similarity, some relevant molecular differences supported this phenotypic diversity: ITEM 17295, producing low biofilm amount, missed the pel operon involved in EPS synthesis and the biofilm-related Toxin-Antitoxin systems (mqsR/mqsA, chpB/chpS); pvdS, required for the pyoverdine synthesis, was a truncated gene in ITEM 17295, harboring, instead, a second aprA involved in milk proteolysis. This work provided new insight into the food spoiler microbiota by identifying these mozzarella cheese spoilers as P. lactis; molecular targets to be exploited in the development of novel preservative strategies were also revealed
Synthesis and characterisation of a new benzamide-containing nitrobenzoxadiazole as a GSTP1-1 inhibitor endowed with high stability to metabolic hydrolysis
The antitumor agent 6-((7-nitrobenzo[c][1,2,5]oxadiazol-4-yl)thio)hexan-1-ol (1) is a potent inhibitor of GSTP1-1, a glutathione S-transferase capable of inhibiting apoptosis by binding to JNK1 and TRAF2. We recently demonstrated that, unlike its parent compound, the benzoyl ester of 1 (compound 3) exhibits negligible reactivity towards GSH, and has a different mode of interaction with GSTP1-1. Unfortunately, 3 is susceptible to rapid metabolic hydrolysis. In an effort to improve the metabolic stability of 3, its ester group has been replaced by an amide, leading to N-(6-((7-nitrobenzo[c][1,2,5]oxadiazol-4-yl)thio)hexyl)benzamide (4). Unlike 3, compound 4 was stable to human liver microsomal carboxylesterases, but retained the ability to disrupt the interaction between GSTP1-1 and TRAF2 regardless of GSH levels. Moreover, 4 exhibited both a higher stability in the presence of GSH and a greater cytotoxicity towards cultured A375 melanoma cells, in comparison with 1 and its analog 2. These findings suggest that 4 deserves further preclinical testing
Quantifying the unknown: issues in simulation validation and their experimental impact
The assessment of the reliability of Monte Carlo simulations is discussed,
with emphasis on uncertainty quantification and the related impact on
experimental results. Methods and techniques to account for epistemic
uncertainties, i.e. for intrinsic knowledge gaps in physics modeling, are
discussed with the support of applications to concrete experimental scenarios.
Ongoing projects regarding the investigation of epistemic uncertainties in the
Geant4 simulation toolkit are reported.Comment: To be published in the Proceedings of the 13th ICATPP Conference on
Astroparticle, Particle, Space Physics and Detectors for Physics
Applications, Villa Olmo, Como, 3-7 October 201
Research in Geant4 electromagnetic physics design, and its effects on computational performance and quality assurance
The Geant4 toolkit offers a rich variety of electromagnetic physics models;
so far the evaluation of this Geant4 domain has been mostly focused on its
physics functionality, while the features of its design and their impact on
simulation accuracy, computational performance and facilities for verification
and validation have not been the object of comparable attention yet, despite
the critical role they play in many experimental applications. A new project is
in progress to study the application of new design concepts and software
techniques in Geant4 electromagnetic physics, and to evaluate how they can
improve on the current simulation capabilities. The application of a
policy-based class design is investigated as a means to achieve the objective
of granular decomposition of processes; this design technique offers various
advantages in terms of flexibility of configuration and computational
performance. The current Geant4 physics models have been re-implemented
according to the new design as a pilot project. The main features of the new
design and first results of performance improvement and testing simplification
are presented; they are relevant to many Geant4 applications, where
computational speed and the containment of resources invested in simulation
production and quality assurance play a critical role.Comment: 4 pages, 4 figures and images, to appear in proceedings of the
Nuclear Science Symposium and Medical Imaging Conference 2009, Orland
Geant4-related R&D for new particle transport methods
A R&D project has been launched in 2009 to address fundamental methods in
radiation transport simulation and revisit Geant4 kernel design to cope with
new experimental requirements. The project focuses on simulation at different
scales in the same experimental environment: this set of problems requires new
methods across the current boundaries of condensed-random-walk and discrete
transport schemes. An exploration is also foreseen about exploiting and
extending already existing Geant4 features to apply Monte Carlo and
deterministic transport methods in the same simulation environment. An overview
of this new R&D associated with Geant4 is presented, together with the first
developments in progress.Comment: 4 pages, to appear in proceedings of the Nuclear Science Symposium
and Medical Imaging Conference 2009, Orland
New models for PIXE simulation with Geant4
Particle induced X-ray emission (PIXE) is a physical effect that is not yet
adequately modelled in Geant4. The current status as in Geant4 9.2 release is
reviewed and new developments are described. The capabilities of the software
prototype are illustrated in application to the shielding of the X-ray
detectors of the eROSITA telescope on the upcoming Spectrum-X-Gamma space
mission.Comment: To be published in the Proceedings of the CHEP (Computing in High
Energy Physics) 2009 conferenc
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