On simultaneous diophantine approximations to ζ(2)\zeta(2) and ζ(3)\zeta(3)

We present a hypergeometric construction of rational approximations to $\zeta(2)$ and $\zeta(3)$ which allows one to demonstrate simultaneously the irrationality of each of the zeta values, as well as to estimate from below certain linear forms in 1, $\zeta(2)$ and $\zeta(3)$ with rational coefficients. A new notion of (simultaneous) diophantine exponent is introduced to formalise the arithmetic structure of these specific linear forms. Finally, the properties of this newer concept are studied and linked to the classical irrationality exponent and its generalisations given recently by S. Fischler.Comment: 23 pages; v2: new subsection 4.5 adde

Cross-contamination of oilseeds by insecticide residues during storage

Pesticide residues are found in oilseeds (rapeseed and sunflower) and crude oils: they are mainly organophosphate insecticides (pirimiphos-methyl, malathion) used in empty storage facilities and for application to stored cereal grains. Even if pests are found in stored oilseeds, French regulation does not allow use of these insecticides on stored oilseeds. These residues arise from cross-contamination from storage bins and facilities, and not from illegal use. This uptake of insecticide residues from their storage environment by oilseeds can lead to levels that exceed regulatory limits. A two-year investigation in grain storage companies allowed us to follow the course of 27 sunflower batches (storage season 2006-2007) and 21 rapeseed batches (storage season 2007-2008), from reception at the storage facilities to outloading. Samples from each of these batches, made at outloading, were analysed by ITERG, looking for insecticide residues. Traceability of oilseeds established by storers allowed us to identify crosscontamination sources. Substances discovered were mostly pirimiphos-methyl, and malathion, dihlorovos (in sunflower), plus chlorpyriphos-methyl and deltaméthrine (one case). Pirimiphos-methyl was most commonly detected, and caused most cases of non-accordance with regulatory levels in rapeseed. Main cross-contamination hazard resulted from treatment of cereals at their receipt during the same period of rapeseed receipt, especially when these cereals treatments were frequent on that elevator. For sunflower, main cross-contamination hazard resulted from treatment of cereals at outloading, just before sunflower seeds were outloaded, especially when these cereals treatments were frequent on that elevator. Other situations led to cross-contaminations, but generally of lower levels: oilseeds stored in bin that contained previously treated cereals, empty bins and handling equipment treated before receipt of oilseeds

Cross-contamination of oilseeds by insecticide residues during storage

Pesticide residues are found in oilseeds (rapeseed and sunflower) and crude oils: they are mainly organophosphate insecticides (pirimiophos-methyl, malathion when authorized) used in empty storage facilities and for direct application to stored cereal grain. Even if some secondary pests are found in stored oilseeds, French regulations do not allow use of these insecticides on stored oilseeds. These residues arise from cross-contamination from storage bins and grain handling equipment of grain stores, and not from illegal use. This uptake of insecticide residues from their storage environment by oilseeds may lead to residue contents that exceed regulatory limits. A three-year investigation in grain storage companies allowed us to follow the course of sunflower batches and rapeseed batches during storage seasons 2006-2007, 2007-2008 and 2008-2009, from reception at the storage facility to outloading. Each of these batches was sampled at outloading, and was analyzed for insecticide residues. Traceability of oilseeds established by grain-store managers allowed us to identify cross-contamination sources. The insecticides that were most commonly detected were pirimiophos-methyl, malathion, and dichlorvos (in sunflower 2006-2007), plus chlorpyriphos-methyl and deltamethrin. Pirimiophos-methyl was the most commonly detected active substance, and caused the most cases of non-accordance with regulatory levels in rapeseed. Cross-contamination could have occurred when cereal grains were treated upon receipt, when rapeseed was also delivered, especially when treatments were done systematically to the cereal grains. For sunflower, the main cross-contamination hazard resulted from treatment of cereals at the period of receipt or at their outloading, just before sunflower seeds batches were outloaded. Another situation led to cross-contamination, but generally at a lower extent: oilseeds stored in bins that contained previously treated cereals, or loaded in empty bins with handling equipment treated before the receipt of oilseeds.Keywords: Oilseed storage, Cross-contamination, Insecticide residues, Rapeseed, Sunflowe

Généralisations quantitatives du critère d’indépendance linéaire de Nesterenko

In this paper we extend Fischler's quantitative generalization of Nesterenko's linear independence criterion, by weakening the hypotheses on the divisors of the coe cients of the linear forms and allowing (to some extent) the linear forms not to tend to 0. Another version of this result is proved, in the spirit of Siegel's criterion, with a recurrence relation veri ed by the linear forms. Finally, the results are restated in a more general setting in terms of convex bodies and lattices of $\mathbb{R}^n$

Rôle immunomodulateur du lenalidomide sur les cellules Natural Killer humaines. Etude des effecteurs lymphoïdes cytotoxiques chez les patients atteints de leucémies aiguës myéloïdes en 1ère rémission complète

La plupart des patients atteints de leucémies aiguës myéloïdes (LAM) sont en rémission complète après la chimiothérapie d'induction (1ère RC). Or, la persistance de cellules cancéreuses résistantes aux traitements et à la réponse immunitaire engendre de nombreuses rechutes. Nos travaux montrent la prééminence et la persistance de cellules NK CD56bright immatures chez ces patients en 1ère RC. Ainsi, tout agent ou tout protocole favorisant la reconstitution ou potentialisant les fonctions cytotoxiques des cellules NK pourrait être bénéfique. Nous avons ainsi choisi d'évaluer le rôle du Lenalidomide sur les cellules NK de donneurs sains. Nos travaux montrent, pour la 1ère fois, un effet direct mais cependant complexe sur les cellules NK. En effet, le Lenalidomide augmente l'expression du CD56 mais diminue la production d'IFN-gamma deux effets qui s'opposent au regard de la description classique des cellules NK CD56bright. L'augmentation du CD56 ne présagerait pas d'un effet bénéfique sur les cellules NK des patients LAM en 1ère RC. De plus, la modulation de l'expression de divers récepteurs de lyse n'a pas d'impact sur les fonctions cytotoxiques de ces effecteurs. Cependant, la diminution de l'expression de l'IFN-gamma pourrait être bénéfique car ce dernier favorise l'expression des molécules du CMH-I par les cellules leucémiques de LAM et inhibant ainsi l'activité cytotoxique des cellules NK. Les nombreuses actions du Lenalidomide sur le microenvironnement tumoral encouragent à poursuivre l'étude de ces effets dans les LAM.Most Acute Myeloide Leukemia (AML) patients achieve complete remission after induction chemotherapy (1st CR). Nevertheless, persistence of resistant tumor cells to treatments and immune response is associated with high risk of relapse. Our works highlight a pre-eminence and persistence of immature CD56 bright NK cells in patients at 1st CR. Thus, every agent or protocol dedicated to improve reconstitution or to potentiate cytotoxic functions of NK cells would be beneficial. Thus, we have chosen to evaluate the role of Lenalidomide upon NK cells of healthy donors. Our works show, for the first time, a direct but complexe effect on NK cells. Indeed, Lenalidomide upregulates the CD56 expression but decreases IFN-gamma production, two opposite effects with respect to the classical description of CD56bright NK cell population. The upregulation of CD56 do not augur a beneficial effect on NK cells of AML patients in 1st CR. Moreover, the modulation of expression of various lytic receptors has no impact on NK cell cytotoxic functions. However, the decrease of IFN-gamma expression coulb be beneficial as it upregulates MHC-I expression on AML leukemic cells and inhibit NK cell cytotoxic activity. The wide range of Lenalidomide actions on tumoral microenvironment is a strong support to pursue the study of its effects on AML

The helium cryogenic plant for the CMS superconducting magnet

A new helium refrigeration plant with a cooling capacity of 800 W at 4.45 K, 4500 W between 60 K and 80 K, and 4 g/s liquefaction simultaneously has been designed and is presently being constructed by Air Liquide for CERN. The refrigeration plant will provide the cooling power for the cool down and the operation of the CMS (Compact Muon Solenoid) superconducting coil whose cold mass weighs 225 t. The refrigeration plant will at first be installed in a surface building for the tests of the superconducting magnet. On completion of the tests the cold box will be moved to its final underground position next to the CMS experimental cavern. This paper presents the process design, describes the main components and explains their selection. (4 refs)

Optimized nucleus isolation protocol from frozen mouse tissues for single nucleus RNA sequencing application

The single cell RNA sequencing technique has been particularly used during the last years, allowing major discoveries. However, the widespread application of this analysis has showed limitations. Indeed, the direct study of fresh tissues is not always feasible, notably in the case of genetically engineered mouse embryo or sensitive tissues whose integrity is affected by classical digestion methods. To overcome these limitations, single nucleus RNA sequencing offers the possibility to work with frozen samples. Thus, single nucleus RNA sequencing can be performed after genotyping-based selection on samples stocked in tissue bank and is applicable to retrospective studies. Therefore, this technique opens the field to a wide range of applications requiring adapted protocols for nucleus isolation according to the tissue considered. Here we developed a protocol of nucleus isolation from frozen murine placenta and pancreas. These two complex tissues were submitted to a combination of enzymatic and manual dissociation before undergoing different steps of washing and centrifugation. The entire protocol was performed with products usually present in a research lab. Before starting the sequencing process, nuclei were sorted by flow cytometry. The results obtained validate the efficiency of this protocol which is easy to set up and does not require the use of commercial kits. This specificity makes it adaptable to different organs and species. The association of this protocol with single nucleus RNA sequencing allows the study of complex samples that resist classical lysis methods due to the presence of fibrotic or fatty tissue, such as fibrotic kidney, tumors, embryonic tissues or fatty pancreas

Increasing Antiproliferative Properties of Endocannabinoids in N1E-115 Neuroblastoma Cells through Inhibition of Their Metabolism

The antitumoral properties of endocannabinoids received a particular attention these last few years. Indeed, these endogenous molecules have been reported to exert cytostatic, apoptotic and antiangiogenic effects in different tumor cell lines and tumor xenografts. Therefore, we investigated the cytotoxicity of three N-acylethanolamines – N-arachidonoylethanolamine (anandamide, AEA), N-palmitoylethanolamine (PEA) and N-oleoylethanolamine (OEA) - which were all able to time- and dose-dependently reduce the viability of murine N1E-115 neuroblastoma cells. Moreover, several inhibitors of FAAH and NAAA, whose presence was confirmed by RT-PCR in the cell line, induced cell cytotoxicity and favored the decrease in cell viability caused by N-acylethanolamines. The most cytotoxic treatment was achieved by the co-incubation of AEA with the selective FAAH inhibitor URB597, which drastically reduced cell viability partly by inhibiting AEA hydrolysis and consequently increasing AEA levels. This combination of molecules synergistically decreased cell proliferation without inducing cell apoptosis or necrosis. We found that these effects are independent of cannabinoid, TRPV1, PPARα, PPARγ or GPR55 receptors activation but seem to occur through a lipid raft-dependent mechanism. These findings further highlight the interest of targeting the endocannabinoid system to treat cancer. More particularly, this emphasizes the great potential benefit of designing novel anti-cancerous therapies based on the association of endocannabinoids and inhibitors of their hydrolysis

Theory of Angular Magnetoresistance in CPP spin valves

The resistance of CPP spin valve is a continuous function of the angle $\theta$ between the magnetizations of both ferromagnets. We use the cicuit theory for non-collinear magnetoelectronics to compute the angular magnetoresistance of CPP spin valves taking the spin accumulation in the ferromagnetic layers into account.Comment: Proceedings of MML'01, 24-29 June 2001, to be published in JMM