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Hypothalamic dysfunction revealed by magnetic resonance diffusion tensor imaging in childhood leukemia survivors treated with cranial radiotherapy but not in craniopharyngeoma survivors

Background: Metabolic complications with obesity are frequent in childhood acute lymphoblastic leukemia (ALL) survivors treated with cranial radiotherapy (CRT). Childhood onset Craniopharyngioma (CP) survivors without hypothalamic (HT) involvement are spared gross obesity. Magnetic resonance diffusion tensor imaging (DTI) provides information of microstructure function of the brain and quantified

The Role of Stochastic Time-Variations in Turbulent Stresses When Predicting Drop Breakup—A Review of Modelling Approaches

Many industrially relevant emulsification devices are of the high-energy type, where drop deformation and subsequent breakup, take place due to intense turbulent fluid–drop interactions. This includes high-pressure homogenizers as well as rotor-stator mixers (also known as high-shear mixers) of various designs. The stress acting on a drop in a turbulent flow field varies over time, occasionally re

A Comment on Niederreiter’s Public Key Cryptosystem

In this comment we show that a recently proposed public key cryptosystem is not safe for most of the practical cases. Furthermore, it is shown that the security of this system is closely connected with the problem of computing logarithms over a finite field.

On the construction of Cartesian authentication codes over symplectic spaces

Various constructions of authentication codes using spaces related to the general linear group have been proposed and analyzed. In the paper the authors describe two new constructions of Cartesian authentication codes using symplectic spaces. This illustrates the feasibility of codes from spaces based on geometries of the other classical groups.

Unconditionally Secure Group Authentication

Group authentication schemes as introduced by Boyd and by Desmedt and Frankel are cryptographic schemes in which only certain designated groups can provide messages with authentication information. In this paper we study unconditionally secure group authentication schemes based on linear perfect secret sharing and authentication schemes, for which we give expressions for the probabilities of succe

The free distance of fixed convolutional rate 2/4 codes meets the Costello bound

The long standing question whether the free distance of fixed rate convolutional codes is as good as the Costello bound was almost solved by K.S. Zigangirov and J.L. Massey (1987). They proved that this is indeed the case for codes with long branch length and rates 2/c, c>or=5. It is shown that there exist fixed convolutional codes of rate 2/4 whose free distance d/sub free/ meets the Costello bou

Bounds on the probability of deception in multiple authentication

The frequently assumed "freshness" constraint on the source states in multiple authentication schemes is not necessary if one allows the encoding rule to change between subsequent transmissions. In the paper it is shown that the main existing lower bounds on the probabilities of successful attack on multiple authentication schemes also hold for this new setup. Furthermore, Stinson's (1988) bound f

On the number of polynomials over GF(2) that factor into 2, 3 or 4 prime polynomials

In this paper a simple method is presented to derive formulas for the number of polynomials over GF(2) which factor into two, three, and four prime polynomials only. A table is given, summarizing the above numbers for polynomials of degree up to 127. Furthermore, the computed values are compared with an asymptotic approximation for these values.