51 research outputs found
CSF neopterin level as a diagnostic marker in primary central nervous system lymphoma
Background The diagnosis of primary central nervous system lymphoma (PCNSL) can be challenging. PCNSL lesions are frequently located deep within the brain, and performing a cerebral biopsy is not always feasible. The aim of this study was to investigate the diagnostic value of CSF neopterin, a marker of neuroinflammation, in immunocompetent patients with suspected PCNSL. Methods We retrospectively reviewed the characteristics of 124 patients with brain tumor (n = 82) or an inflammatory CNS disorder (n = 42) in whom CSF neopterin levels were assessed. Twenty-eight patients had PCNSL, 54 patients had another type of brain tumor (glioma n = 36, metastasis n = 13, other n = 5), and 13 patients had a pseudotumoral inflammatory brain lesion. Results CSF neopterin levels were significantly higher in the patients with PCNSL than in those with other brain tumors (41.8 vs 5.1 nmol/L, P < .001), those with pseudotumoral inflammatory brain lesions (41.8 vs 4.3 nmol/L, P < .001), and those with nontumefactive inflammatory CNS disorders (41.8 vs 3.8 nmol/L, P < .001). In the 95 patients with space-occupying brain lesions, at a cutoff of 10 nmol/L, the sensitivity of this approach was 96% and the specificity was 93% for the diagnosis of PCNSL. The positive and negative predictive values were 84% and 98%, respectively. Conclusion Assessing CSF neopterin levels in patients with a suspected brain tumor might be helpful for the positive and differential diagnosis of PCNSL. A prospective study is warranted to confirm these result
An EfïŹcient Framework for Design and Assessment of Arithmetic Operators with Reduced-Precision Redundancy
International audienceFor arithmetic circuits, Reduced-Precision Redundancy (RPR) is considered to be a viable alternative to Triple Modular Redundancy (TMR), as it offers signiïŹcant power reduction. However, efïŹcient implementation and assessment of hardware arithmetic operators with RPR is still a challenge. In this work we propose a lightweight RPR design methodology that exploits the capabilities of modern synthesis and simulation tools to simplify the design and veriïŹcation of robust arithmetic operators. To demonstrate the effectiveness of the proposed framework we apply it to implement and compare two commonly used RPR schemes. Our experimental results show that the proposed framework simpliïŹes the design and provides robustness indicators with a maximum coefïŹcient of variation of 14.7% with a 3Ă experimentation speed-up at a cost of 25% computational effort compared to an exhaustive approach
Small FPGA based Multiplication-Inversion Unit for Normal Basis Representation in
International audienceHalving methods have been proposed for parallel implementation of ECC primitives on multicore processors. In hardware, they can also provide protection against some side channel attacks (thanks to parallel independent operations). But they require affine coordinates for curve points and costly inversions. We propose a new combined multiplication-inversion unit for binary field extensions and halving based ECC methods optimized for FPGAs. We target small area solutions compared to very fast but costly ones from state-of-art. Our solution is based on permuted normal basis, Massey-Omura multiplication and Itoh-Tsujii inversion algorithms. Our FPGA implementations show better efficiency for large fields
Unités arithmétiques reconfigurables pour cryptoprocesseurs robustes aux attaques
Cette thĂšse porte sur l'Ă©tude, la conception matĂ©rielle, la validation thĂ©orique et pratique, et enfin la comparaison de diffĂ©rents opĂ©rateurs arithmĂ©tiques pour des cryptosystĂšmes basĂ©s sur les courbes elliptiques (ECC). Les solutions proposĂ©es doivent ĂȘtre robustes contre certaines attaques par canaux cachĂ©s tout en Ă©tant performantes en matĂ©riel, tant au niveau de la vitesse d'exĂ©cution que de la surface utilisĂ©e. Dans ECC, nous cherchons Ă protĂ©ger la clĂ© secrĂšte, un grand entier, utilisĂ© lors de la multiplication scalaire. Pour nous protĂ©ger contre des attaques par observation, nous avons utilisĂ© certaines reprĂ©sentations des nombres et des algorithmes de calcul pour rendre difficiles certaines attaques ; comme par exemple rendre alĂ©atoires certaines reprĂ©sentations des nombres manipulĂ©s, en recodant certaines valeurs internes, tout en garantissant que les valeurs calculĂ©es soient correctes. Ainsi, l'utilisation de la reprĂ©sentation en chiffres signĂ©s, du systĂšme de base double (DBNS) et multiple (MBNS) ont Ă©tĂ© Ă©tudiĂ©s. Toutes les techniques de recodage ont Ă©tĂ© validĂ©es thĂ©oriquement, simulĂ©es intensivement en logiciel, et enfin implantĂ©es en matĂ©riel (FPGA et ASIC). Une attaque par canaux cachĂ©s de type template a de plus Ă©tĂ© rĂ©alisĂ©e pour Ă©valuer la robustesse d'un cryptosystĂšme utilisant certaines de nos solutions. Enfin, une Ă©tude au niveau matĂ©riel a Ă©tĂ© menĂ©e dans le but de fournir Ă un cryptosystĂšme ECC un comportement rĂ©gulier des opĂ©rations effectuĂ©es lors de la multiplication scalaire afin de se protĂ©ger contre certaines attaques par observation.This PhD thesis focuses on the study, the hardware design, the theoretical and practical validation, and eventually the comparison of different arithmetic operators for cryptosystems based on elliptic curves (ECC). Provided solutions must be robust against some side-channel attacks, and efficient at a hardware level (execution speed and area). In the case of ECC, we want to protect the secret key, a large integer, used in the scalar multiplication. Our protection methods use representations of numbers, and behaviour of algorithms to make more difficult some attacks. For instance, we randomly change some representations of manipulated numbers while ensuring that computed values are correct. Redundant representations like signed-digit representation, the double- (DBNS) and multi-base number system (MBNS) have been studied. A proposed method provides an on-the-fly MBNS recoding which operates in parallel to curve-level operations and at very high speed. All recoding techniques have been theoretically validated, simulated extensively in software, and finally implemented in hardware (FPGA and ASIC). A side-channel attack called template attack is also carried out to evaluate the robustness of a cryptosystem using a redundant number representation. Eventually, a study is conducted at the hardware level to provide an ECC cryptosystem with a regular behaviour of computed operations during the scalar multiplication so as to protect against some side-channel attacks.RENNES1-Bibl. Ă©lectronique (352382106) / SudocSudocFranceF
RĂšgle anglaise versus rĂšgle amĂ©ricaine dâallocation des frais de justice : une analyse expĂ©rimentale
International audienceIn this paper, we conduct an experiment in order to analyze how the trial costs allocation rule (i.e., American or English rule) may shape the efficiency of the litigation process, via its effect on the attorneyâs effort, the deterrence of meritless claims and the plaintiffâs incentives to go to court. It appears that the English rule helps to screen out low-quality claims, partly by lessening attorneysâ incentives to provide effort to defend such cases ex post (and hence discouraging potential clients to go to trial ex ante).Dans cet article, nous analysons expĂ©rimentalement lâimpact potentiel de la rĂšgle dâallocation des frais de justice (rĂšgle amĂ©ricaine ou anglaise) sur lâefficacitĂ© de la procĂ©dure judiciaire, via son effet sur lâeffort de lâavocat, la dissuasion des recours illĂ©gitimes et les incitations du demandeur Ă aller en justice. DâaprĂšs nos rĂ©sultats, il semble que la rĂšgle anglaise contribue Ă diminuer le nombre de recours illĂ©gitimes, notamment en rĂ©duisant les incitations des avocats Ă exercer un effort Ă©levĂ© pour dĂ©fendre ce type dâaffaires ex post (et donc en dĂ©courageant les clients potentiels dâintenter un procĂšs ex ante)
Legal Fees, Cost-Shifting Rules and Litigation: Experimental Evidence
International audienceIn this paper, we conduct an experiment in order to explore how the legal fee arrangement (i.e. flat or contingent fees) and the trial costs allocation rule (i.e. American or English rule) may shape the efficiency of the litigation process, via their effect on the lawyerâs effort, the deterrence of frivolous lawsuits and the plaintiffâs incentives to go to court. In our experimental context, it is shown that the combination of contingent fees and English rule is the best setting in terms of effort incentives, but enhances frivolous lawsuits. This result may indicate potentially that the recent tendency observed in European countries to combine contingency and English rule would be desirable only if it is associated to mechanisms discouraging plaintiffs to sue meritless cases
Gender Differences in Legal Disputes: The Case of French Labor Courts
Cet article porte sur les diffĂ©rences de genre dans les litiges prudâhomaux en France. Nous rĂ©alisons une analyse empirique de donnĂ©es concernant la phase de conciliation prĂ©alable au procĂšs et les dĂ©cisions des juges lors de la phase de jugement. Pour cela, nous avons crĂ©Ă© une nouvelle base de donnĂ©es Ă partir de documents juridiques. Les rĂ©sultats sont doubles. PremiĂšrement, les femmes sont moins susceptibles que les hommes de parvenir Ă une entente avant le procĂšs lorsquâelles poursuivent leur employeur, sauf dans les cas dâun licenciement. DeuxiĂšmement, nous constatons que, toutes choses Ă©gales par ailleurs, les femmes ont plus de chances dâobtenir gain de cause lors de la phase de jugement. Ces rĂ©sultats suggĂšrent que les femmes portent, en moyenne, des affaires de meilleure qualitĂ© devant le conseil des prudâhommes. Cet effet pourrait sâexpliquer par les revendications initiales qui sont portĂ©es contre les employeurs, ainsi que par les diffĂ©rences de comportement de nĂ©gociation pendant la phase de conciliation prĂ©alable au procĂšs.This paper focuses on gender differences in French Labor Courts. We empirically investigate data from the pretrial conciliation phase and the judgesâ decisions in the trial phase. For that purpose, we compiled a novel database from legal documents. The results are twofold. First, women are less likely to reach pretrial agreement compared to men when they sue their employer, except for dismissal cases. Second, we find that all things being equal, women are more likely to succeed in the trial phase. Taken together, these results suggest that women bring, on average, higher quality cases to the French Labor Court. This effect might be explained by the intitial demands that are brought against the employers, as well as gender differences in bargaining behavior during the pretrial conciliation phase
Donor Derived Candida stellimalicola in a Clinical Specimen: Preservation Fluid Contamination During Pancreas Procurement
International audienc
Particle absorption (aP) in the surface water of the Mackenzie Delta Region during 4 expeditions from spring to fall in 2019
Absorbance of particles retained on GF/F (0.7 ”m) filters was measured using a Varian Cary 100 spectrophotometer equipped with an integrated sphere. Absorbance and reflectance spectra were measured by placing a sample filter in front and back of an integrating sphere, respectively (so-called Transmittance-Reflectance or T-R method; Tassan & Ferrari 1995; doi:10.4319/lo.1995.40.8.1358). An appropriate beta factor specific to the geometry of the instrument was used to calculate absorption coefficients of particles (Tassan & Ferrari 2002; doi:10.1093/plankt/24.8.757)
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