Gerald Bourgeois

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ABSTRACT In controlled environment studies, the influence of temperature and wetness duration on infection of strawberry leaves by Mycosphaerella fragariae was quantified by inoculating plants with a conidial suspension and incubating them at various combinations of temperature (5 to 35 degrees C) and leaf wetness duration (0 to 96 h). Infection was(More)
Our goal was to evaluate the accuracy of stereotactic technique using MRI in thalamic functional neurosurgery. A phantom study was designed to estimate errors due to MRI distortion. Stereotactic mechanical accuracy was assessed with the Suetens-Gybels-Vandermeulen (SGV) angiographic localiser. Three-dimensional MRI reconstructions of 86 therapeutic lesions(More)
Isariins B, C and D, isolated from a strain of Isaria felina, were shown to be cyclodepsipeptides constituted by a pentapeptide cyclized through a beta-hydroxyacid. The nature of the latter and the sequence of the peptide were determined for each compound. Relations between insecticidal activity and structure of the depsipeptides were pointed out.
f, g ∈ L(E) where E is a k vector space of dimension d. We introduce the relation (*): exp(t.f + g) = exp(t.f) • exp(g) for any t ∈ k or N; we study the connections between the relations (*) and f • g = g • f for d = 2 or 3. Let d = 2: if k = R and if (*) is verified for t ∈ N then f • g = g • f ; we obtain all the couples f , g verifying (*) on C and such(More)
Let A, B be n × n complex matrices such that C = AB − BA and A commute. For n = 2, we prove that A, B are simultaneously triangularizable. For n ≥ 3, we give an example of matrices A, B such that the pair (A, B) does not have property L of Motzkin-Taussky, and such that B and C are not simultaneously triangularizable. Finally, we estimate the complexity of(More)
on améliore une attaque algébrique de NTRU (où le paramètre q est une puissance de 2), due à Silverman, Smart et Vercauteren ; au lieu de considérer, comme les précédents, les 2 premiers bits d'un vecteur de Witt attaché à la recherche de la clé secrète, on considère ici les 4 premiers bits, ce qui fournit des équations supplémentaires de degrés 4 puis 8.(More)
We present an algebraic attack on NTRU (restricted to the case where the parameter q is a power of two) using the method of the Witt vectors proposed by Silverman, Smart and Vercauteren [17]; the latter considered only the first two bits of a Witt vector attached to the recovering of the secret key in order to reduce the problem to the resolution of an(More)
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