Non-Gaussian Distributions in Extended Dynamical Systems

We propose a novel mechanism for the origin of non-Gaussian tails in the probability distribution functions (PDFs) of local variables in nonlinear, diffusive, dynamical systems including passive scalars advected by chaotic velocity fields. Intermittent fluctuations on appropriate time scales in the amplitude of the (chaotic) noise can lead to exponential tails. We provide numerical evidence for such behavior in deterministic, discrete-time passive scalar models. Different possibilities for PDFs are also outlined.Comment: 12 pages and 6 figs obtainable from the authors, LaTex file, OSU-preprint-

Phosphorylation of the Leukemic Oncoprotein EVI1 on Serine 196 Modulates DNA Binding, Transcriptional Repression and Transforming Ability

The EVI1 (ecotropic viral integration site 1) gene at 3q26 codes for a transcriptional regulator with an essential role in haematopoiesis. Overexpression of EVI1 in acute myeloid leukaemia (AML) is frequently associated with 3q26 rearrangements and confers extremely poor prognosis. EVI1 mediates transcriptional regulation, signalling, and epigenetic modifications by interacting with DNA, proteins and protein complexes. To explore to what extent protein phosphorylation impacts on EVI1 functions, we analysed endogenous EVI1 protein from a high EVI1 expressing Fanconi anaemia (FA) derived AML cell line. Mass spectrometric analysis of immunoprecipitated EVI1 revealed phosphorylation at serine 196 (S196) in the sixth zinc finger of the N-terminal zinc finger domain. Mutated EVI1 with an aspartate substitution at serine 196 (S196D), which mimics serine phosphorylation of this site, exhibited reduced DNA-binding and transcriptional repression from a gene promotor selectively targeted by the N-terminal zinc finger domain. Forced expression of the S196D mutant significantly reduced EVI1 mediated transformation of Rat1 fibroblasts. While EVI1-mediated serial replating of murine haematopoietic progenitors was maintained by EVI1-S196D, this was associated with significantly higher Evi1-trancript levels compared with WT-EVI1 or EVI1-S196A, mimicking S196 non-phosphorylated EVI1. These data suggest that EVI1 function is modulated by phosphorylation of the first zinc finger domain

Variations of plasma enzyme activities and inflammation markers in severe head injury: a multivariate approach for patient monitoring and outcome prediction.

peer reviewe

New artiodactyl ruminant mammal from the Late Oligocene of Pakistan

Dental and postcranial material of the bovid−like ruminant Palaeohypsodontus zinensis sp. nov. is reported from the Oligocene of the Bugti Hills (Balochistan, Pakistan). This finding extends the geographic distribution of this dentally highly derived ruminant, which was previously restricted to the early Oligocene of Mongolia and China. The inclusion of Palaeohypsodontus within the Bovidae is disputed on the basis of astragalus characters, and the taxonomic status of the Oligo−Miocene Eurasian bovid−like ruminants is briefly discussed. It is concluded that the assignment of Palaeohypsodontus to the Bovidae would be premature. More dental and postcranial material of this genus as well as additional fossils of early bovids are necessary to shed new light on the phylogenetic relationships within the first representatives of that family in Eurasia

investigations on crack propagation under cyclical isothermal and thermo-mechanical loadings for a type 304-l stainless steel used for pressurized water reactor

International audienceThe integrity of structures exhibiting flaws in Pressurized Water Reactor (PWR) has to be assessed to meet safety criteria. This paper deals with crack-propagation under cyclic thermo-mechanical loadings, as encountered in class I austenitic pipes of PWR's. To this end, a device called PROFATH was designed. The specimen is a pre-cracked thick-walled tube undergoing a set of thermal cycles and loaded with a static mechanical force. During the first part of the cycle, a high frequency induction coil heats the external wall. Then, the heating system stops and the specimen is cooled down by running water inside the tube. Finite element calculations show that only a region half-way along the tube should be heated to ensure adequate structural effect. In the heated zone, the machining of a sharp circumferential groove ensures the propagation of a unique crack. An electro-mechanical jack controls the level of the mechanical static load. To obtain a very precise thermal mapping, a specific specimen with dedicated instrumentation is used: 20 thermocouples are appropriately located on the outer surface and along the wall thickness. During the test, the crack-propagation is estimated through crack-opening measurements (compliance method). Now, tests have been carried out at different levels of thermo-mechanical loadings. These tests allow having an evaluation of the pertinence of the correction proposed by the RSE-M for a significant plasticity. And these tests can also be used to have a confirmation or to propose an extension of the validity domain