8,154 research outputs found
Threshold cryptography based on Asmuth–Bloom secret sharing
Cataloged from PDF version of article.In this paper, we investigate how threshold cryptography can be conducted with the Asmuth-Bloom secret sharing scheme and present three novel function sharing schemes for RSA, ElGamal and Paillier cryptosysterns. To the best of our knowledge, these are the first provably secure threshold cryptosystems realized using the Asmuth-Bloom secret sharing. Proposed schemes are comparable in performance to earlier proposals in threshold cryptography. (c) 2007 Elsevier Inc. All rights reserved
Thermal QCD Sum Rules Study of Vector Charmonium and Bottomonium States
We calculate the masses and leptonic decay constants of the heavy vector
quarkonia, and mesons at finite temperature. In particular,
considering the thermal spectral density as well as additional operators coming
up at finite temperature, the thermal QCD sum rules are acquired. Our numerical
calculations demonstrate that the masses and decay constants are insensitive to
the variation of temperature up to , however after this point,
they start to fall altering the temperature. At deconfinement temperature, the
decay constants attain roughly to 45% of their vacuum values, while the masses
are diminished about 12%, and 2.5% for and states,
respectively. The obtained results at zero temperature are in good consistency
with the existing experimental data as well as predictions of the other
nonperturbative models. Considerable decreasing in the values of the decay
constants can be considered as a sign of the quark gluon plasma phase
transition.Comment: 14 Pages, 8 Figures and 2 Table
Optimal subset-difference broadcast encryption with free riders
Cataloged from PDF version of article.Broadcast encryption (BE) deals with secure transmission of a message to a group of receivers such that only an authorized subset of receivers can decrypt the message. The transmission cost of a BE system can be reduced considerably if a limited number of free riders can be tolerated in the system. in this paper, we study the problem of how to optimally place a given number of free riders in a subset-difference (SD)-based BE system, which is currently the most efficient BE scheme in use and has also been incorporated in standards, and we propose a polynomial-time optimal placement algorithm and three more efficient heuristics for this problem. Simulation experiments show that SD-based BE schemes can benefit significantly from the proposed algorithms. (C) 2009 Elsevier Inc. All rights reserved
Thomas-Fermi-Poisson theory of screening for latterally confined and unconfined two-dimensional electron systems in strong magnetic fields
We examine within the self-consistent Thomas-Fermi-Poisson approach the
low-temperature screening properties of a two-dimensional electron gas (2DEG)
subjected to strong perpendicular magnetic fields. Numerical results for the
unconfined 2DEG are compared with those for a simplified Hall bar geometry
realized by two different confinement models. It is shown that in the strongly
non-linear screening limit of zero temperature the total variation of the
screened potential is related by simple analytical expressions to the amplitude
of an applied harmonic modulation potential and to the strength of the magnetic
field.Comment: 12 pages, 12 figure
Anisotropic elasticity in confocal studies of colloidal crystals
We consider the theory of fluctuations of a colloidal solid observed in a
confocal slice. For a cubic crystal we study the evolution of the projected
elastic properties as a function of the anisotropy of the crystal using
numerical methods based on the fast Fourier transform. In certain situations of
high symmetry we find exact analytic results for the projected fluctuations.Comment: 6 pages, 7 figure
Hydrodynamic Equation for the Breakdown of the Quantum Hall Effect in a Uniform Current
The hydrodynamic equation for the spatial and temporal evolution of the
electron temperature T_e in the breakdown of the quantum Hall effect at
even-integer filling factors in a uniform current density j is derived from the
Boltzmann-type equation, which takes into account electron-electron and
electron-phonon scatterings. The derived equation has a drift term, which is
proportional to j and to the first spatial derivative of T_e. Applied to the
spatial evolution of T_e in a sample with an abrupt change of the width along
the current direction, the equation gives a distinct dependence on the current
direction as well as a critical relaxation, in agreement with the recent
experiments.Comment: 4 pages, 1 Postscript figure, corrected equations, to be published in
J. Phys. Soc. Jpn. 70 (2001) No.
5-Hydroxymethylcytosine Loss in Conjunctival Melanoma.
Conjunctival and cutaneous melanoma partially share similar clinical and molecular backgrounds. As 5-hydroxymethylcytosine (5-hmC) loss has been demonstrated in cutaneous melanoma, we decided to assess if similar changes were occurring in conjunctival melanoma.
5-methylcytosine (5-mC), 5-hmC and TET2 were respectively identified by immunohistochemistry and RNA ISH in 40 conjunctival nevi and 37 conjunctival melanomas. Clinicopathological correlations were established.
5-mC, TET2 and 5-hmC were respectively identified in 67.5%, 95% and 100% of conjunctival nevi and in 81.1%, 35.1% and 54% of conjunctival melanomas. A significant 5-hmC and TET2 loss was identified in conjunctival melanoma comparing to nevus, as well as a significant correlation between TET2 and 5-hmC expression. In the melanomas, 5-hmC expression was only significantly associated with local lymphatic invasion, but not with other clinicopathological parameters. There was a correlation between TET2 expression and the localization of the tumors. 5-mC expression was not associated with any clinicopathological parameters.
We identified a significant 5-hmC loss in conjunctival melanoma similar to cutaneous melanoma. This loss may possibly be attributed to TET2 loss or IDH1 mutations. 5-hmC loss in conjunctival melanoma may help in the differential diagnosis between atypical conjunctival nevus and conjunctival melanoma
Allelopathic potential of macrofungi on germinating maize (Zea mays L.) grain
The effect of methanol extracts of 10 macrofungi was evaluated on grain germination of maize (Zea mays L.). Germination percentage, radicle and plumule length and the level of carbohydrates and fatty acids were measured. Fungal metabolites inhibited germination up to 90.96%, plumule (97.77%) and radicle (92.83%) development. Plumule and radicle lengths were stimulated 35.26 and 10.60% in some assays, respectively. The fungal metabolites decreased the glucose (97.60%), sucrose (90.34%), fructose (96.85%), maltose (95.64%), oleic acid (97.50%) and linoleic acid (98.25%) levels, whereas increasing levels of the glucose (165.14%), sucrose (166.53%), fructose (83.18%), maltose (124.73%), oleic acid (6975.00%) and linoleic acid (5233.33%) were detected in some assays. It is concluded that macrofungi metabolites have commonly inhibitory effects on physiological and morphological processes of germinating maize grain except for considerable increases in the some parameters investigated
mESAdb: microRNA expression and sequence analysis database
Cataloged from PDF version of article.microRNA expression and sequence analysis database (http://konulab.fen.bilkent.edu.tr/mirna/) (mESAdb) is a regularly updated database for the multivariate analysis of sequences and expression of microRNAs from multiple taxa. mESAdb is modular and has a user interface implemented in PHP and JavaScript and coupled with statistical analysis and visualization packages written for the R language. The database primarily comprises mature microRNA sequences and their target data, along with selected human, mouse and zebrafish expression data sets. mESAdb analysis modules allow (i) mining of microRNA expression data sets for subsets of microRNAs selected manually or by motif; (ii) pair-wise multivariate analysis of expression data sets within and between taxa; and (iii) association of microRNA subsets with annotation databases, HUGE Navigator, KEGG and GO. The use of existing and customized R packages facilitates future addition of data sets and analysis tools. Furthermore, the ability to upload and analyze user-specified data sets makes mESAdb an interactive and expandable analysis tool for microRNA sequence and expression data
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