2,220 research outputs found
Commentary on digital evidence and electronic signature of a consumer credit contract in France
Eric A. Caprioli gives a commentary on some decisions in France relating to electronic signatures and on-line contracts
Comparison of Different Methods for Nonlinear Diffusive Shock Acceleration
We provide a both qualitative and quantitative comparison among different
approaches aimed to solve the problem of non-linear diffusive acceleration of
particles at shocks. In particular, we show that state-of-the-art models
(numerical, Monte Carlo and semi-analytical), even if based on different
physical assumptions and implementations, for typical environmental parameters
lead to very consistent results in terms of shock hydrodynamics, cosmic ray
spectrum and also escaping flux spectrum and anisotropy. Strong points and
limits of each approach are also discussed, as a function of the problem one
wants to study.Comment: 26 pages, 4 figures, published version (references updated
The HI absorption distance of HESS J1943+213 favours its extragalactic nature
The H.E.S.S. collaboration (Abramowski et al. 2011) dicovered a new TeV
point-like source HESS J1943+213 in the Galactic plane and suggested three
possible low-energy-band counterparts: a -ray binary, a pulsar wind
nebula (PWN), or a BL Lacertae object. We measure the distance to the radio
counterpart G57.76-1.29 of HESS J1943+213. We analyze Very Large Array
observations to obtain a reliable HI absorption spectrum.The resulting distance
limit is 16 kpc. This distance strongly supports that HESS J1943+213 is
an extragalactic source, consistent with the preferred counterpart of the HESS
collaboration.Comment: 3 figures, 2 pages, A&A accepte
Characterization of an emergent clone of enteroinvasive Escherichia coli circulating in Europe
Enteroinvasive Escherichia coli (EIEC) cause intestinal illness indistinguishable from that caused by Shigella, mainly in developing countries.
Recently an upsurge of cases of EIEC infections has been observed in Europe, with two large outbreaks occurring in Italy and in the
United Kingdom. We have characterized phenotypically and genotypically the strains responsible for these epidemics together with an
additional isolate from a sporadic case isolated in Spain. The three isolates belonged to the same rare serotype O96:H19 and were of
sequence type ST-99, never reported before in EIEC or Shigella. The EIEC strains investigated possessed all the virulence genes
harboured on the large plasmid conferring the invasive phenotype to EIEC and Shigella while showing only some of the known
chromosomal virulence genes and none of the described pathoadaptative mutations. At the same time, they displayed motility abilities
and biochemical requirements resembling more closely those of the non-pathogenic E. coli rather than the EIEC and Shigella strains used
as reference. Our observations suggested that the O96:H19 strains belong to an emerging EIEC clone, which could be the result of a
recent event of acquisition of the invasion plasmid by commensal E. coli
Kinetic simulations of mildly relativistic shocks:I. Particle acceleration in high Mach number shocks
The reintroduction of Castor fiber in Piedmont (Italy): An integrated SWOT-spatial multicriteria based approach for the analysis of suitability scenarios
The Castor fiber or Eurasian beaver can change its habitat by building dams and creating ponds. For this reason, Castor fiber is known as an “ecosystem engineer” for aquatic and riparian environments. Despite its ecological importance, at the beginning of the 20th century the population was reduced to only 1200 beavers in Europe and Asia, due to uncontrolled hunting. Recently, some reintroductions and translocations have partly re-established the population. In Italy, however, the beaver disappeared in the 16th century and no action has been taken despite the recommendation of the Council of Europe to perform a feasibility study. This research evaluates beaver reintroduction and identifies suitable areas in Italy and, in particular, in the Piedmont region. In order to achieve this, a SWOT analysis combined with a Spatial Multicriteria Analysis was performed. Firstly, the zoological and ethological aspects concerning this rodent were studied, as well as the historical reasons that led to its disappearance in Italy and near extinction in Eurasia. Secondly, Strengths, Weaknesses, Opportunities and Threats (SWOT) of the territory were identified for beaver reintroduction. The SWOT analysis was implemented, as the starting point for the spatial multicriteria analysis. Thirdly, the Multicriteria Spatial Decision Support System (MC-SDSS) was structured into two criteria, i.e. Potentials and Criticalities, representing the spatialization of strengths and weaknesses. The final result of the MC-SDSS is a map showing suitable areas for beaver reintroduction in Piedmont. This map is the weighted sum of the maps of criticalities and potentialities, performed through a set of GIS operations and weighted through a pairwise comparison of criteria by experts. The analysis was conducted for the Piedmont region, but the integrated approach and the set of criteria can also be applied in other regions. Moreover, this mixed-method approach takes into account the characteristics necessary for the choice of suitable beaver habitats and also includes economic and social aspects. Therefore, it is an improvement on the Habitat Suitability Index (HIS), generally used in reintroductions. The aspects considered in the analysis are fundamental for the future development of a shared action plan, which considers both technical and social motivations and acts for the long-term on a wide area
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Vertical Macular Asymmetry Measures Derived From SD-OCT for Detection of Early Glaucoma.
PurposeTo test the hypothesis that vertical asymmetry in macular ganglion cell/inner plexiform layer (GCIPL) thickness can improve detection of early glaucoma.MethodsSixty-nine normal eyes and 101 glaucoma eyes had macular imaging with spectral-domain optical coherence tomography (OCT; 200 × 200 cube). The resulting GCIPL thickness matrix was grouped into a 20 × 20 superpixel array and superior superpixels were compared to their inferior counterparts. A global asymmetry index (AI) was defined as the grand mean of the asymmetry ratios. To measure local asymmetry, the corresponding thickness measurements of three rows above and below the horizontal raphe were compared individually and in combinations. Global and local AIs were compared to the best-performing GCIPL thickness parameters with area under the receiver operating curves (AUC) and sensitivity/specificities.ResultsAge or axial length did not influence AIs in normal subjects (P ≥ 0.08). Global and local AIs were significantly higher in the glaucoma group compared to normal eyes. Minimum (AUC = 0.962, 95% confidence interval [CI]: 0.936-0.989) and inferotemporal thickness (AUC = 0.944, 95% CI: 0.910-0.977; P = 0.122) performed best for detection of early glaucoma. The AUC for global AI was 0.851 (95% CI: 0.792-0.909) compared to 0.916 (95% CI: 0.874-0.958) for the best local AI. Combining minimum or inferotemporal GCIPL thickness and the best local AI led to higher partial AUCs (0.088 and 0.085, 90% specificity, P = 0.120 and 0.130, respectively) than GCIPL thickness measures.ConclusionsMacular vertical thickness asymmetry measures did not perform better than sectoral or minimum GCIPL thickness for detection of early glaucoma. Combining local asymmetry parameters with the best sectoral GCIPL thickness measures enhanced this task
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Magnetic Resonance Imaging of Optic Nerve Traction During Adduction in Primary Open-Angle Glaucoma With Normal Intraocular Pressure.
PurposeWe used magnetic resonance imaging (MRI) to ascertain effects of optic nerve (ON) traction in adduction, a phenomenon proposed as neuropathic in primary open-angle glaucoma (POAG).MethodsSeventeen patients with POAG and maximal IOP ≤ 20 mm Hg, and 31 controls underwent MRI in central gaze and 20° to 30° abduction and adduction. Optic nerve and sheath area centroids permitted computation of midorbital lengths versus minimum paths.ResultsAverage mean deviation (±SEM) was -8.2 ± 1.2 dB in the 15 patients with POAG having interpretable perimetry. In central gaze, ON path length in POAG was significantly more redundant (104.5 ± 0.4% of geometric minimum) than in controls (102.9 ± 0.4%, P = 2.96 × 10-4). In both groups the ON became significantly straighter in adduction (28.6 ± 0.8° in POAG, 26.8 ± 1.1° in controls) than central gaze and abduction. In adduction, the ON in POAG straightened to 102.0% ± 0.2% of minimum path length versus 104.5% ± 0.4% in central gaze (P = 5.7 × 10-7), compared with controls who straightened to 101.6% ± 0.1% from 102.9% ± 0.3% in central gaze (P = 8.7 × 10-6); and globes retracted 0.73 ± 0.09 mm in POAG, but only 0.07 ± 0.08 mm in controls (P = 8.8 × 10-7). Both effects were confirmed in age-matched controls, and remained significant after correction for significant effects of age and axial globe length (P = 0.005).ConclusionsAlthough tethering and elongation of ON and sheath are normal in adduction, adduction is associated with abnormally great globe retraction in POAG without elevated IOP. Traction in adduction may cause mechanical overloading of the ON head and peripapillary sclera, thus contributing to or resulting from the optic neuropathy of glaucoma independent of IOP
Comparison of Outcomes between Endoscopic and Transcleral Cyclophotocoagulation.
Importance: Traditionally cyclophotocoagulation has been reserved as a treatment of last resort for eyes with advanced stage glaucoma, but increasingly it is offered to eyes with less severe disease. Endoscopic approaches in particular are utilized in increasing numbers of patients despite only a small number of publications on its results. Objective: The purpose of this study was to compare the efficacy and safety of endoscopic and transcleral cyclophotocoagulation (ECP and TCP) procedures in eyes with refractory glaucomas. Design, Setting, and Participants: A chart review was performed on consecutive patients who underwent ECP and TCP at a tertiary ophthalmology care center between January 2000 and December 2010. Cases with fewer than 3 months of follow-up or that had concurrent pressure reducing procedures were excluded. The main outcome measures examined were intraocular pressure (IOP), number of glaucoma medications, best corrected visual acuity (BCVA), additional glaucoma procedure required, and complications. Main Outcomes and Measures: Forty-two eyes (42 patients) that underwent ECP and forty-four eyes (44 patients) that underwent TCP were identified. The TCP group had a statistically higher mean age (71.2 ± 16.7 vs. 58.1 ± 22.9 years, respectively), larger proportion of neovascular glaucoma (40.9% vs. 16.7%), worse initial BCVA (logMAR 2.86 vs. 1.81), and higher preoperative IOP (45.3 vs. 26.6 mmHg) than the ECP group. At 12 months follow-up, the mean IOP difference between groups was not statistically significant, although the change in IOP from baseline to 12 months was greater for the TCP group (p = 0.006). The rates of progression to no light perception (NLP) and phthisis bulbi were significantly higher amongst TCP eyes than ECP eyes (27.2% vs. 4.8%, p = 0.017, and 20.5% vs. 0%, p = 0.003, respectively). Of these eyes that progressed, a majority had neovascular glaucoma (NVG). Corneal decompensation was the most frequent complication following ECP (11.9%). Conclusions and Relevance: In patients with preoperative BCVA of 20/400 or better, overall complication rates (cystoid macular edema, exudative retinal detachment, inflammation, cornea decompensation) were higher after ECP than with TCP. In refractory glaucomas in a real world setting (not a trial), TCP was more frequently used in ischemic eyes. TCP was associated with a higher rate of progression to phthisis bulbi and loss of light perception than ECP. However, ECP was associated with a clinically significant rate of corneal decompensation. These outcomes likely were related to the severity of underlying ocular diseases found in these eyes
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