15,868 research outputs found
Accidental matter at the LHC
We classify weak-scale extensions of the Standard Model which automatically
preserve its accidental and approximate symmetry structure at the
renormalizable level and which are hence invisible to low-energy indirect
probes. By requiring the consistency of the effective field theory up to scales
of 10^15 GeV and after applying cosmological constraints, we arrive at a finite
set of possibilities that we analyze in detail. One of the most striking
signatures of this framework is the presence of new charged and/or colored
states which can be efficiently produced in high-energy particle colliders and
which are stable on the scale of detectors.Comment: 55 pages, 13 figure
Technical quality assessment of an optoelectronic system for movement analysis
The Optoelectronic Systems (OS) are largely used in gait analysis to evaluate the motor performances of healthy subjects and patients. The accuracy of marker trajectories reconstruction depends on several aspects: the number of cameras, the dimension and position
of the calibration volume, and the chosen calibration procedure. In this paper we propose a methodology to evaluate the eects of the mentioned sources of error on the reconstruction of marker trajectories. The novel contribution of the present work consists in the dimension of the tested calibration volumes, which is comparable with the ones normally used in gait analysis; in addition, to simulate trajectories during clinical gait analysis, we provide non-default
paths for markers as inputs. Several calibration procedures are implemented and the same trial is processed with each calibration le, also considering dierent cameras congurations.
The RMSEs between the measured trajectories and the optimal ones are calculated for each comparison. To investigate the signicant dierences between the computed indices, an ANOVA analysis is implemented. The RMSE is sensible to the variations of the considered calibration volume and the camera congurations and it is always inferior to 43 mm
The effect of a nucleating agent on lamellar growth in melt-crystallizing polyethylene oxide
The effects of a (non co-crystallizing) nucleating agent on secondary
nucleation rate and final lamellar thickness in isothermally melt-crystallizing
polyethylene oxide are considered. SAXS reveals that lamellae formed in
nucleated samples are thinner than in the pure samples crystallized at the same
undercoolings. These results are in quantitative agreement with growth rate
data obtained by calorimetry, and are interpreted as the effect of a local
decrease of the basal surface tension, determined mainly by the nucleant
molecules diffused out of the regions being about to crystallize. Quantitative
agreement with a simple lattice model allows for some interpretation of the
mechanism.Comment: submitted to Journal of Applied Physics (first version on 22 Apr
2002
The HCV Sicily Network: a web-based model for the management of HCV chronic liver diseases
Epidemiological studies report that in Sicily reside about 30,000 citizens with a diagnosis of chronic hepatitis due to HCV. The availability of direct antiviral action (DAA) is a real therapeutic breakthrough, but the high cost of the therapeutic regimes limits their use and forced the National Health System to establish clinical priority for the treatment
Applications of Trichoderma to prevent Phaeomoniella chlamydospora infections in organic nurseries
In order to prevent or reduce infection in grapevine nurseries, greenhouse and nursery trials were carried out to evaluate the effects of Trichoderma harzianum (Rootshield\u27) on the morpho-physiological characteristics of grapevine and on Phaeomoniella chlamydospora artificially inoculated on potted cuttings. The long-distance activity of Trichoderma against Botrytis cinerea was also examined. The study was performed in a commercial nursery where plants were grown organically. Results greatly depended on the vine-growth stage at which Richoderma was applied. Treatment at rooting was the most effective, whilst callusing-box application or treatments at both rooting and callusing gave inconsistent but generally negative results. Treatment at rooting further improved the quantitative and qualitative characteristics of the root system, and increased the percentage of certifiable vines produced. Moreover, Richoderma application also reduced the necrotic area caused by B. cinerea inoculated on the leaves collected from Richoderma-treated plants and the extent of necrosis of P. chlamydospora-inoculated cuttings. This reduction in necrosis was significantly higher 15 months after inoculation. On the other hand, Richoderma increased vine mortality at the end of the growing season compared with untreated plants. On the whole, only when it was applied at rooting did Richoderma produce positive effects on the morpho-phisiological characteristics of grapevine and increased its tolerance to stress-related diseases, such as forms of esca found in the nursery
Wood discoloration and decay in grapevines with esca proper and their relationship with foliar symptoms
From two Italian vineyards affected with esca proper, vineyard A (Borghi, FC, Emilia-Romagna) and vineyard B (Controguerra, TE, Abruzzo), located in different wine-growing areas and with different cultivars, 165 vines were collected that had shown the leaf symptoms of esca proper in the years before. Each vine was inspected and the cubic volume of the main symptoms in the trunk was measured: discoloration, including the various forms of dark necrosis, and decay. In each vine of both vineyards the extent of wood deterioration was compared with the severity of the leaf symptoms recorded in the years before the vines were cut down. The existence of a correlation between discoloration and decay in the wood colonisation process was explored. No correlation was found between the severity of the wood deterioration and the severity of the leaf symptoms. The typical leaf symptoms were found also on vines that had only wood discoloration without any decay. There was no correlation between wood discoloration and decay in vineyard A in which the vine wood was more degraded, with a greater incidence of decay. In vineyard B, however, in which the incidence of decay was less, a correlation between decay and discoloration was potentially found
Rotational sensitivity of the "G-Pisa" gyrolaser
G-Pisa is an experiment investigating the possibility to operate a high
sensitivity laser gyroscope with area less than for improving the
performances of the mirrors suspensions of the gravitational wave antenna
Virgo. The experimental set-up consists in a He-Ne ring laser with a 4 mirrors
square cavity. The laser is pumped by an RF discharge where the RF oscillator
includes the laser plasma in order to reach a better stability. The contrast of
the Sagnac fringes is typically above 50% and a stable regime has been reached
with the laser operating both single mode or multimode. The effect of hydrogen
contamination on the laser was also checked. A low-frequency sensitivity, below
, in the range of has been
measured.Comment: 6 pages, 6 figures, presented at the EFTF-IFCS joint conference 200
Contribution to the vascular flora of Papasidero (north-western Calabria, Italy)
A floristic survey of the Papasidero municipality (54.65 km2) was carried out from 2008 to 2011, allowing us to list 580 specific and infraspecific taxa (567 verified by us), belonging to 353 genera and 89 families. Several species are rather interesting from a phytogeographic and/or conservation point of view. 14 exotic species were also recorded, 10 of which are considered invasive in the regional flora. The most represented families are Asteraceae (66 taxa), Fabaceae (56), Lamiaceae (40), Poaceae (31), while most represented genera are Trifolium (11), Euphorbia and Ophrys (9), Lathyrus and Geranium (8). Biological and chorological spectra show a clear dominance of Hemicriptophytes and Mediterranean elements respectively, as one can expect based on the climatic conditions of the area at issues
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