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 Efficient 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 significant power reduction. However, efficient 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 verification 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 simplifies the design and provides robustness indicators with a maximum coefficient of variation of 14.7% with a 3× 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 GF(2m)GF(2^m)

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 thèse porte sur l'étude, la conception matérielle, la validation théorique et pratique, et enfin la comparaison de différents opérateurs arithmétiques pour des cryptosystèmes basés sur les courbes elliptiques (ECC). Les solutions proposées doivent être robustes contre certaines attaques par canaux cachés tout en étant performantes en matériel, tant au niveau de la vitesse d'exécution que de la surface utilisée. Dans ECC, nous cherchons à protéger la clé secrète, un grand entier, utilisé lors de la multiplication scalaire. Pour nous protéger contre des attaques par observation, nous avons utilisé certaines représentations des nombres et des algorithmes de calcul pour rendre difficiles certaines attaques ; comme par exemple rendre aléatoires certaines représentations des nombres manipulés, en recodant certaines valeurs internes, tout en garantissant que les valeurs calculées soient correctes. Ainsi, l'utilisation de la représentation en chiffres signés, du système de base double (DBNS) et multiple (MBNS) ont été étudiés. Toutes les techniques de recodage ont été validées théoriquement, simulées intensivement en logiciel, et enfin implantées en matériel (FPGA et ASIC). Une attaque par canaux cachés de type template a de plus été réalisée pour évaluer la robustesse d'un cryptosystème utilisant certaines de nos solutions. Enfin, une étude au niveau matériel a été menée dans le but de fournir à un cryptosystème ECC un comportement régulier des opérations effectuées lors de la multiplication scalaire afin de se protéger 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. électronique (352382106) / SudocSudocFranceF

Règle anglaise versus règle américaine d’allocation des frais de justice : une analyse expérimentale

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 attorney’s effort, the deterrence of meritless claims and the plaintiff’s incentives to go to court. It appears that the English rule helps to screen out low-quality claims, partly by lessening attorneys’ 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 expérimentalement l’impact potentiel de la règle d’allocation des frais de justice (règle américaine ou anglaise) sur l’efficacité de la procédure judiciaire, via son effet sur l’effort de l’avocat, la dissuasion des recours illégitimes et les incitations du demandeur à aller en justice. D’après nos résultats, il semble que la règle anglaise contribue à diminuer le nombre de recours illégitimes, notamment en réduisant les incitations des avocats à exercer un effort élevé pour défendre ce type d’affaires ex post (et donc en décourageant les clients potentiels d’intenter un procès 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 lawyer’s effort, the deterrence of frivolous lawsuits and the plaintiff’s 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

Pretrial settlement and coercion: An experiment

International audiencePretrial settlements attempts can be either freely chosen by litigating parties or imposed to them, notably by law or by a judge, which renders the settlement stage mandatory in the latter case, as in mandatory mediation procedures. In a lab experiment, we first analyze the determinants of the litigants' willingness to bargain. Then we investigate the impact of a bargaining obligation on the litigants' behavior during the negotiation, by varying both the probability that the constraint is enforced and payoff asymmetry between parties. We show that the willingness to bargain depends on one's relative advantage in terms of expected judgment levels (after or instead of a pretrial settlement attempt), on gender and on the probability of being effectively constrained. We also highlight that players who are forced to bargain are more inclined to concessions within the negotiation than the pairs which freely bargain. Finally, we show that forced bargaining leads to more egalitarian agreements. Our results may have important implications in terms of public policy regarding mandatory mediation

Gender Differences in Legal Disputes: The Case of French Labor Courts

Cet article porte sur les différences de genre dans les litiges prud’homaux en France. Nous réalisons une analyse empirique de données concernant la phase de conciliation préalable au procès et les décisions des juges lors de la phase de jugement. Pour cela, nous avons créé une nouvelle base de données à partir de documents juridiques. Les résultats sont doubles. Premièrement, les femmes sont moins susceptibles que les hommes de parvenir à une entente avant le procès lorsqu’elles poursuivent leur employeur, sauf dans les cas d’un licenciement. Deuxièmement, nous constatons que, toutes choses égales par ailleurs, les femmes ont plus de chances d’obtenir gain de cause lors de la phase de jugement. Ces résultats suggèrent que les femmes portent, en moyenne, des affaires de meilleure qualité devant le conseil des prud’hommes. Cet effet pourrait s’expliquer par les revendications initiales qui sont portées contre les employeurs, ainsi que par les différences de comportement de négociation pendant la phase de conciliation préalable au procès.This paper focuses on gender differences in French Labor Courts. We empirically investigate data from the pretrial conciliation phase and the judges’ 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

Evaluation of the Hg Contamination from Gold Mining in French Guiana at the Watershed Scale Using Hg Isotopic Composition in River Sediments

International audienceArtisanal and small-scale gold mining (ASGM) is a major source of mercury (Hg) contamination in Amazonian ecosystems, due to remobilization of geogenic Hg from mined soil, and anthropogenic Hg used for gold amalgamation. To assess these two relative contributions, Hg stable isotope composition together with geochemical variables were determined in sediment samples collected in the early 2000s across the main watersheds of French Guiana. Mercury in sediment was found associated with organic matter and Fe/Al oxides. Total Hg concentrations were correlated (p < 0.001) to both mass-dependent (δ202Hg) and odd-mass-independent fractionation (Δ199Hg) indicating that the Hg isotopic composition of river sediments reflects the extent of contamination, with two isotopic end-members for pristine or geogenic (δ202Hg = −2.53 ± 0.23‰, Δ199Hg = −0.62 ± 0.10‰) and for ASGM contaminated (δ202Hg = −0.42 ± 0.20‰, Δ199Hg = −0.01 ± 0.07‰) sediments. A binary mixing model showed that the contribution of anthropogenic Hg in river sediments varied widely (ca. 0 to 100%) and reflected the geographical and historical monitoring of ASGM activities in French Guiana. These results highlight that Hg isotopic measurements in archived sediments allow retrospective assessment of Hg pollution in ASGM-impacted regions and evaluation of its temporal evolution

Impact of land-use on PAH transfer in sub-surface water as recorded by CaCO3 concretions in urban underground structures (Paris, France).

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