1,721,581 research outputs found
Measurement of the associated production of the Higgs boson with a vector boson in 13 TeV pp collisions with the ATLAS detector
No full textAfter the Higgs discovery at LHC in 2012, most of ATLAS analyses are focusing the attention on precision measurements of Higgs kinematic properties and on the search of new decay modes sensitive to physics Beyond the Standard Model. One of the most interesting channels is the Higgs boson decay into two b-quarks due to the large branching ratio (58%). The best sensitivity is presently
obtained by studying the associated Higgs boson production with a vector boson V (V = W or Z) decaying leptonically. The same dataset has been re-interpreted in the Simplified Template Cross Section framework. This framework facilitates the measurement of the differential pp → V H cross section used to extract information on the Higgs couplings and to put limits on Beyond the Standard Model effects. In this paper an overview of the most recent results on the observation of V H production and H → b¯b decay mode will be presented, together with the measurements of the V H, H → b¯b production as a function of the vector boson transverse momentum
Primo rinvenimento in Sicilia di Typha laxmannii (Typhaceae)
Full text linkFirst record of Typha laxmannii Lepech. (Typhaceae) in Sicily. Typha laxmannii Lepech. (Typhaceae) is here reported, for the first time, in Sicily at Scopello, near Castellammare del Golfo (NW Sicily). This species is compared with the congenerics occurring in the region; dichotomous key and description are also given to make the identification easier
Rigidity and spontaneous curvature of lipidic monolayers in the presence of trehalose: a measurement in the DOPE inverted hexagonal phase
No full textRobustness studies of the photomultipliers reading out TileCal, the central hadron calorimeter of the ATLAS experiment
No full textThe ATLAS Tile Calorimeter (TileCal) is the central section of the hadronic calorimeter of the ATLAS experiment. This sampling calorimeter uses steel plates as absorber and scintillating tiles as active medium. The light produced by the passage of charged particles is transmitted by wavelength shifting fibres to photo-multiplier tubes (PMTs), located in the outer part of the calorimeter. The readout is segmented into about 5000 cells, each one being read out by two PMTs in parallel. The detector readout geometry will not be changed for the Phase II of the High Luminosity Large Hadron Collider (HL-LHC) operation. A challenging goal is to understand whether the full sample of PMTs installed at the beginning of the ATLAS detector operation can be used until completion of the HL-LHC program or not. For this reason, a reliable study of the PMT robustness against ageing is required. Detailed studies modelling the PMT response variation as a function of the integrated anode charge were done. The PMT response evolution during LHC Run 2 of the PMTs mounted on the detector was studied for different amounts of anode integrated charge. At the same time, a test bench arrangement was used to study on a small PMT sample the ageing effects by LED or laser excitation. They integrated in a short time (1 year) anode charge amounts similar to those expected in the HL-LHC era for the PMTs reading out the most exposed TileCal cells. Results from on-detector PMT studies and test bench data are in agreement and led to the estimation that only the samples reading out the most exposed cells (8% of total 10,000 unit sample) may have a global response loss up to 50% (combined degradation of quantum efficiency and dynode gain). For this reason, and to preserve safe detector operation, it was decided to replace that 8% of PMTs with the latest version of the same geometry model produced by the vendor. Test bench measurements comparing old and new PMT models show that the latter type has improved performance in terms of response loss as a function of the anode integrated charge
Calibration and performance of the ATLAS Tile Calorimeter during the LHC Run 2
Full text linkThe central hadronic calorimeter of the ATLAS experiment at the Large Hadron Collider (LHC) is a sampling calorimeter made up of steel and scintillating tiles. TileCal is regularly monitored and calibrated by different calibration
systems. A description of the different sources and of the results on the calorimeter performance during the LHC Run 2 is present
MONOTROPA HYPOPHEGEA WALLR., A NEW RECORD FOR THE SICILIAN FLORA
No full textDuring field investigations in the Mountains around Palermo, an unusual population of Monotropa sp. was found. After revision of the taxonomic literature and herbarium specimens, it was referred to Monotropa hypophegea Wallr. This species is closely related to M. hypopytis L., and in the past was considered only a variety (Pignatti 1982) or a subspecies (Křisa 1972) ) of it. More recently this entity has been considered an independent taxon deserving the rank of species (Conti et al. 2005). The most important morphological differences between the two taxa are the number of flowers in the raceme and the hairiness of sepals, petals and capsule. The individuals of the observed population have short racemes, with less than 8 flowers, are glabrous in all parts, including the sepals and inside petals and have glabrous, spherical capsules. On the contrary M. hypopytis has denser racemes (generally with 8-11 flowers), flowers hairy in the inner part of petals and in the sepals, and ovoid capsules. According to the literature (Pignatti 1982) M. hyphophegea is typical of deciduous forests, especially beech woods, while M. hypopitys prefers coniferous forests. However, in Sicily M. hipopytis is known only in the beech forests of the Madonie and the Nebrodi Mountains, with the alone exception of one locality in a black pine forest of the Etna Mountain (Giardina et al. 2007). M. hyphophagea, that was unknown in the island (Giardina et al. 2007, Raimondo et al. 2010), was found in an artificial Pinus halepensis, Pinus pinea and Cupressus sempervirens plantation. In particular, the locality where the species was found is in the Casaboli Wood at 790 m a.s.l., in the municipality of Monreale, near Palermo. It is an old reforestation with an high degree of dynamism to the return of natural vegetation, represented by Quercus ilex L. in the form of dense shrubs that constitute a undergrowth below the conifers. This discovery represents a further enrichment for the flora of Sicily. In particular the Mountains around Palermo are one of the richest areas in terms of plant biodiversity in Sicily. This is underlined by the recent description of punctual endemic species such as Silene kemoniana, Brassica trichocarpa, Hieracium busambarense and Sorbus busambarensis (C. Brullo et al. 2012, C. Brullo et al. 2013, Caldarella 2014, Castellano 2012)
Smart city. Da una definizione alla costruzione di un’agenda pubblica condivisa: comparazione tra PAES di città mediterranee
No full textDa un lato occorre
avere degli indicatori smart funzionali e oggettivi e delle graduatorie di merito, dall’altro costruire una smart
city non può non concentrarsi sulle peculiarità delle identità locali e i saperi contestuali e la cultura di un città.
Quindi ci siamo chiesti: Quali gli indicatori da adottare? Dove e come si gioca effettivamente la competizione
per diventare Smart City? I PAES sono degli strumenti e non il fine, la loro efficacia sarà nella reale possibilità
di implementarli e monitorarli, e, cosa fondamentale, di implementare politiche, e interventi pilota e di
comunicazione che induca a nuovi comportamenti smart gli stessi cittadini
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Acute ascending aortic dissection during transaortic balloon-expandable aortic valve implantation
No full textTranscatheter aortic valve replacement (TAVR) has shown good early and midterm results in high-risk or inoperable patients with severe symptomatic aortic valve stenosis.1 TAVR is generally accomplished with either antegrade transapical or retrograde transfemoral access. If these approaches are not technically possible, transaortic TAVR (Tao-TAVR) is feasible and effective. Tao-TAVR can be performed through either a ministernotomy or a minithoracotomy.2,3 The advantages of Tao-TAVR are mainly related to (1) the short distance between the delivery system and the aortic annulus that enables a precise valve deployment and (2) the possibility to schedule for TAVR patients who have contraindications for the transapical and/or transfemoral approach. Nowadays there is a wide experience with both transapical and transfemoral TAVR, and consequently their related complications are known, predictable, and manageable.4 On the other hand, Tao-TAVR is a relatively new technique that is performed without specifically designed devices, and its possible complications are still not widely known and described. We describe a case of acute ascending aortic dissection during Tao-TAVR that required emergency conversion to open surgery
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