Unexpected high levels of Cobalamin (Vitamin B12): Numerous interferences are decreased by PEG treatment.

Cobalamin (Vitamin B12) deficiency is a common cause of anemia. High levels of serum cobalamin is mainly due to cobalamin supplementation. It has also been associated with hematological malignancies, liver or renal diseases. Cobalamin is sometimes found elevated in autoimmune disorders and infectious diseases but concerns are raised on the fact that those serum increases might be due to interference with immunoassays. Those data’s shed the lights on the high prevalence of interference in patients with unexpected high cobalamin level. Precipitation with PEG appears to be an easy and costless method to increase the reliability of cobalamin dosage. In accordance with our results, we recommand to treat systematically every serum with a cobalamin >1500 ng/L

Les troubles musculo-squelettiques chez les étudiants en musique

Les troubles musculo-squelettiques chez les musiciens peuvent être la source significative d’une incapacité mesurable en perte de temps de pratique, en réduction de dextérité, et parfois en arrêt prématuré de carrière. Sachant qu’environ 1 musicien professionnel sur 10 doit stopper sa carrière à cause de syndromes douloureux, nous avons voulu savoir quelle était l’étendue de ces troubles sur la population estudiantine de la Haute Ecole de Musique de Lausanne et de Sion. Nous avons donc fait passer un questionnaire aux étudiants pour recenser les douleurs, les habitudes de pratique instrumentale et les loisirs. Il ressort que 70% des répondants souffrent de symptômes physiques et 32% ressentent des douleurs depuis plus d’une année

Faint dwarf galaxies in the Next Generation Virgo cluster Survey

The Next Generation Virgo Cluster Survey (NGVS) is a CFHT Large Program that is using the wide field of view capabilities of the MegaCam camera to map the entire Virgo Cluster from its core to virial radius. The observing strategy has been optimized to detect very low surface brightness structures in the cluster, including intracluster stellar streams and faint dwarf spheroidal galaxies. We present here the current status of this ongoing survey, with an emphasis on the detection and analysis of the very low-mass galaxies in the cluster that have been revealed by the NGVS.Comment: 6 pages, 2 figures, Conference Proceedings: "A Universe of Dwarf Galaxies", 14-18 June 2010, Lyon, Franc

On ranked and bounded Kohnert posets

In this paper, we explore combinatorial properties of the posets associated with Kohnert polynomials. In particular, we determine a sufficient condition guaranteeing when such ``Kohnert posets'' are bounded and two necessary conditions for when they are ranked. Moreover, we apply the aforementioned conditions to find complete characterizations of when Kohnert posets are bounded and when they are ranked in special cases, including those associated with Demazure characters

A hard-sphere quasicrystal stabilized by configurational entropy

Due to their aperiodic nature, quasicrystals are one of the least understood phases in statistical physics. One significant complication they present in comparison to their periodic counterparts is the fact that any quasicrystal can be realized as an exponentially large number of different tilings, resulting in a significant contribution to the quasicrystal entropy. Here, we use free-energy calculations to demonstrate that it is this configurational entropy which stabilizes a dodecagonal quasicrystal in a binary mixture of hard spheres on a plane. Our calculations also allow us to quantitatively confirm that in this system all tiling realizations are essentially equally likely, with free-energy differences less than 0.0001$k_BT$ per particle -- an observation that could be the related to the observation of only random tilings in soft matter quasicrystals. Owing to the simplicity of the model and its available counterparts in colloidal experiments, we believe that this system is a excellent candidate to achieve the long-awaited quasicrystal self-assembly on the micron scale.Comment: Contains an SI as ancillary fil

Realistic modeling of entorhinal cortex field potentials and interpretation of epileptic activity in the guinea pig isolated brain preparation.

Mechanisms underlying epileptic activities recorded from entorhinal cortex (EC) were studied through a computational model based on review of cytoarchitectonic and neurobiological data about this structure. The purpose of this study is to describe and use this model to interpret epileptiform discharge patterns recorded in an experimental model of ictogenesis (guinea-pig isolated brain perfused with bicuculline). A macroscopic modeling approach representing synaptic interactions between cells subpopulations in the EC was chosen for its adequacy to mimic field potentials reflecting overall dynamics rising from interconnected cells populations. Therefore, intrinsic properties of neurons were not included in the modeling design. Model parameters were adjusted from an identification procedure based on quantitative comparison between real and simulated signals. For both EC deep and superficial layers, results show that the model generates very realistic signals regarding temporal dynamics, spectral features and cross-correlation values. These simulations allowed us to infer information about the evolution of synaptic transmission between principal cell and interneuronal populations and about connectivity between deep and superficial layers during the transition from background to ictal activity. In the model, this transition was obtained for increased excitation in deep versus superficial layers. Transitions between epileptiform activities (interictal spikes, fast onset activity (25Hz), ictal bursting activity) were explained by changes of parameters mainly related to GABAergic interactions. Notably, the model predicted an important role of GABA(a,fast) and GABA(b) receptor-mediated inhibition in the generation of ictal fast onset and burst activities, respectively. These findings are discussed with respect to experimental data

An improved hydrodynamic model for percolation and drainage dynamics for household and agricultural waste beds

This study focuses on the hydrodynamic modelling of percolation and drainage cycles in the context of solid-state anaerobic digestion and fermentation (VFA platform) of household solid wastes (HSW) in leach bed reactors. Attention was given to the characterization of the water distribution and hydrodynamic properties of the beds. The experimental procedure enabled the measurement of water content in waste beds at different states of compaction during injection and drainage, and this for two types of HSW and for two other type of wastes. A numerical model, set up with experimental data from water content measurements, highlighted that a capillary-free dual-porosity model was not able to correctly reproduce all the hydrodynamic features and particularly the drainage dynamics. The model was improved by adding a reservoir water fraction to macroporosity which allowed to correctly simulate dynamics. This model, validated with data obtained from agricultural wastes, enabled to explain more precisely the water behaviour during percolation processes and these results should be useful for driving either solid-state anaerobic digestion or fermentation reactors. Indeed, this implies that the recirculation regime will impact the renewal of the immobile water fraction in macroporosity, inducing different concentration levels of fermentation products in the leachate