2,397 research outputs found
Anonymous certification for E-assessment opinion polls
Anonymous certification (AC) refers to cryptographic mechanisms in which users get certified from trusted issuers, with regard to some pre-defined user attributes, in order to produce presentation tokens. Such tokens satisfy service providers’ access policies, without revealing sensitive user information. AC systems are generally classified under two main different categories: (1) one-time show credentials that can be shown once for avoiding their originating user being traced from one transaction to another, and (2) multi-show credentials that can be used many times while avoiding their originating user to be traced. In this paper, we consider e-assessment opinion polls scenarios and propose an AC scheme where the one-time show property is relevant for making sure each user cannot hand in more than one poll in order to get significant results. To mitigate cheating, the scheme is provided with two extra procedures: attribute revocation and anonymity removal. The correctness of our scheme, as well as unforgeability, privacy and anonymity removal, are analyzed and demonstrated
In Vivo Corneal Microstructural Changes in Herpetic Stromal Keratitis: A Spectral-Domain Optical Coherence Tomography Analysis
Purpose: To describe and analyze the microstructural changes in herpetic stromal keratitis (HSK) observed in vivo by spectral-domain ocular coherence tomography (SD-OCT) at different stages of the disease.
Methods: A prospective, cross-sectional, observational, and comparative SD-OCT analysis of corneas with active and inactive keratitis was performed, and the pathologic differences between the necrotizing and non-necrotizing forms of the disease were analyzed.
Results: Fifty-three corneas belonging to 43 (81.1%) women and 10 (18.8%) men with a mean age of 41.0 years were included for analysis. Twenty-four (45.3%) eyes had active keratitis, and 29 (54.7%) had inactive keratitis; the majority (83.0%) had the non-necrotizing form. Most corneas (79.1%) with active keratitis showed stromal edema and inflammatory infiltrates. Almost half of the active lesions affected the visual axis, were found at mid-stromal depth, and had a medium density. By contrast, corneas with inactive keratitis were characterized by stromal scarring (89.6%), epithelial remodeling (72.4%), and stromal thinning (68.9%). In contrast to non-necrotizing corneas, those with necrotizing HSK showed severe stromal scarring, inflammatory infiltration, and thinning. Additionally, most necrotizing lesions (77.7%) affected the visual axis and had a higher density (P = 0.010).
Conclusion: Active HSK is characterized by significant epithelial and stromal thickening and the inactive disease manifests epithelial remodeling at sites of stromal thinning due to scarring. Necrotizing keratitis is characterized by distorted corneal architecture, substantial stromal inflammatory infiltration, and thinning. In vivo SD-OCT analysis permitted a better understanding of the inflammatory and repair mechanisms occurring in this blinding corneal disease
Ionized and neutral gas in the peculiar star/cluster complex in NGC 6946
The characteristics of ionized and HI gas in the peculiar star/cluster
complex in NGC 6946, obtained with the 6-m telescope (BTA) SAO RAS, the Gemini
North telescope, and the Westerbork Synthesis Radio Telescope (WSRT), are
presented. The complex is unusual as hosting a super star cluster, the most
massive known in an apparently non-interacting giant galaxy. It contains a
number of smaller clusters and is bordered by a sharp C-shaped rim. We found
that the complex is additionally unusual in having peculiar gas kinematics. The
velocity field of the ionized gas reveals a deep oval minimum, ~300 pc in size,
centered 7" east of the supercluster. The Vr of the ionized gas in the dip
center is 100 km/s lower than in its surroundings, and emission lines within
the dip appear to be shock excited. This dip is near the center of an HI hole
and a semi-ring of HII regions. The HI (and less certainly, HII) velocity
fields reveal expansion, with the velocity reaching ~30 km/s at a distance
about 300 pc from the center of expansion, which is near the deep minimum
position. The super star cluster is at the western rim of the minimum. The
sharp western rim of the whole complex is plausibly a manifestation of a
regular dust arc along the complex edge. Different hypotheses about the complex
and the Vr depression origins are discussed, including a HVC/dark mini-halo
impact, a BCD galaxy merging, and a gas outflow due to release of energy from
the supercluster stars.Comment: MN RAS, accepte
Organizing pneumonia due to actinomycosis: an undescribed association
Organizing pneumonia is a pathologic entity characterized by intra-alveolar buds of granulation tissue that can extend to the bronchiolar lumen. It is a non-specific finding reflecting a pattern of pulmonary response to aggression that can be cryptogenic or associated with several causes. Pulmonary actinomycosis is a rare infectious disease, of bacterial aetiology, and of difficult diagnosis. This disease usually causes non-specific respiratory symptoms and radiological findings, and the treatment is based on the use of antibiotics. The authors describe a clinical case of a 53-year-old male smoker (50 pack years), initially seen for complaints of right-sided chest pain and sub-febrile temperature. Imaging studies revealed a mass in the inferior right lobe and enlarged mediastinal lymph nodes. Empirical treatment with antibiotics caused partial and temporary improvement. Transthoracic biopsy revealed a pattern of organizing pneumonia with giant multinucleated cell granulomas. Repeat imaging studies revealed an enlargement of the pulmonary mass and therefore a right inferior lobectomy was performed. The pathologic study revealed a histological pattern of organizing pneumonia surrounding inflammatory bronchiectasis with a large number of Actinomyces colonies. To our knowledge there is presently no report in the literature of organizing pneumonia associated with Actinomyces infection
Quality control of leather by terahertz time domain spectroscopy
We use terahertz time-domain spectroscopy combined with effective-medium theory to measure moisture content and thickness of leather simultaneously. These results demonstrate that this method could become a standard quality control test for the industrial tanning process
Selection of extreme phenotypes: the role of clinical observation in translational research
Systematic collection of phenotypes and their correlation with molecular data has been proposed as a useful method to advance in the study of disease. Although some databases for animal species are being developed, progress in humans is slow, probably due to the multifactorial origin of many human diseases and to the intricacy of accurately classifying phenotypes, among other factors. An alternative approach has been to identify and to study individuals or families with very characteristic, clinically relevant phenotypes. This strategy has shown increased efficiency to identify the molecular features underlying such phenotypes. While on most occasions the subjects selected for these studies presented harmful phenotypes, a few studies have been performed in individuals with very favourable phenotypes. The consistent results achieved suggest that it seems logical to further develop this strategy as a methodology to study human disease, including cancer. The identification and the study with high-throughput techniques of individuals showing a markedly decreased risk of developing cancer or of cancer patients presenting either an unusually favourable prognosis or striking responses following a specific treatment, might be promising ways to maximize the yield of this approach and to reveal the molecular causes that explain those phenotypes and thus highlight useful therapeutic targets. This manuscript reviews the current status of selection of extreme phenotypes in cancer research and provides directions for future development of this methodology
The young open cluster NGC 7067 using Strömgren photometry
© 2016 The Authors. NGC 7067 is a young open cluster located in the direction between the first and the second Galactic quadrants and close to the Perseus spiral arm. This makes it useful for studies of the nature of the MilkyWay spiral arms. Strömgren photometry taken with theWide Field Camera at the Isaac Newton Telescope allowed us to compute individual physical parameters for the observed stars and hence to derive the cluster's physical parameters. Spectra from the 1.93-m telescope at the Observatoire de Haute-Provence helped to check and improve the results. We obtained photometry for 1233 stars, individual physical parameters for 515 and spectra for 9 of them. The 139 selected cluster members lead to a cluster distance of 4.4 ±0.4 kpc, with an age below log10(t(yr)) = 7.3 and a present mass of 1260 ± 160 M⊙. The morphology of the data reveals that the centre of the cluster is at (α, δ) = (21: 24: 13.69, +48: 00: 39.2) J2000, with a radius of 6.1 arcmin. Strömgren and spectroscopic data allowed us to improve the previous parameters available for the cluster in the literature
The young open cluster NGC 7067 using Stromgren photometry
© The Authors 2016. Published by Oxford University Press on behalf of The Royal Astronomical Society. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited. M. Monguio et al, ' The young open cluster NGC 7067 using Stromgren photometry ', MNRAS Vol 466(3): 3636-3647 (2017), first published online 17 December 2016, the version of record is available online via doi: 10.1093/mnras/stw3302NGC 7067 is a young open cluster located in the direction between the first and the second Galactic quadrants and close to the Perseus spiral arm. This makes it useful for studies of the nature of the Milky Way spiral arms. Stromgren photometry taken with the Wide Field Camera at the Isaac Newton Telescope allowed us to compute individual physical parameters for the bserved stars and hence to derive cluster’s physical parameters. Spectra from the 1.93-m telescope at the Observatoire de Haute-Provence helped to check and improve the results. We obtained photometry for 1233 stars, individual physical parameters for 515 and spectra for 9 of them. The 139 selected cluster members lead to a cluster distance of 4.4±0.4 kpc, with an age below log10(t(yr))=7.3 and a present Mass of 1260±160M⊙. The morphology of the data reveals that the centre of the cluster is at (α,δ)=(21: 24: 13.69,+48: 00: 39.2) J2000, with a radius of 6.′1. Stromgren and spectroscopic data allowed us to improve the previous parameters available for the cluster in the literature.Peer reviewedFinal Published versio
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