A Dual Origin of the Xist Gene from a Protein-Coding Gene and a Set of Transposable Elements

X-chromosome inactivation, which occurs in female eutherian mammals is controlled by a complex X-linked locus termed the X-inactivation center (XIC). Previously it was proposed that genes of the XIC evolved, at least in part, as a result of pseudogenization of protein-coding genes. In this study we show that the key XIC gene Xist, which displays fragmentary homology to a protein-coding gene Lnx3, emerged de novo in early eutherians by integration of mobile elements which gave rise to simple tandem repeats. The Xist gene promoter region and four out of ten exons found in eutherians retain homology to exons of the Lnx3 gene. The remaining six Xist exons including those with simple tandem repeats detectable in their structure have similarity to different transposable elements. Integration of mobile elements into Xist accompanies the overall evolution of the gene and presumably continues in contemporary eutherian species. Additionally we showed that the combination of remnants of protein-coding sequences and mobile elements is not unique to the Xist gene and is found in other XIC genes producing non-coding nuclear RNA

Investigation of Attainable Equilibrium Sets for Clearance of Flight Control Laws

A systematic investigation of aircraft equilibrium states and their local stability characteristics is used for clearance of flight control laws for a large variety of manoeuvres. The proposed approach is illustrated by clearance of the LPV control laws designed in a wide subsonic region for the F-18HARV aircraft in level flight conditions and clearance of the F-16 aircraft longitudinal and lateral-directional stability augmentation system for high range of incidence and intensive velocity roll rotation

Pushing Ahead - SUPRA Airplane Model for Upset Recovery

One of the primary objectives of the European Union 7th Framework Program research project SUPRA – “Simulation of Upset Recovery in Aviation” – is the development and validation of the aerodynamic model of a generic large transport airplane aimed for piloted simulation in the post-stall region and upset recovery training. Modeling methods for prediction of post-stall flight dynamics, use of the wind tunnel data from different experimental facilities complemented by CFD analysis, validation criteria, nonlinear dynamics investigation and piloted simulation results are presented in this paper. The aerodynamic model was successfully validated by a number of expert pilots and found acceptable for upset recovery training

Flight Envelope Expansion via Active Control Solutions for a Generic Tailless Aircraft

Aircraft dynamics at high angles of attack due to loss of stability and control essentially limits its manoeuvrability. Modern control systems implement flight envelope protection at the cost of maneuverability to improve safety in these conditions. Flight envelope boundaries, which are set taking into account deterioration of stability and controllability due to separated flow, can be expanded by appropriate design of control laws. However, such a design requires extensive analysis of the maneuver envelope of the airframe and its utilization by the flight envelope protection laws. The reliability of this analysis depends on the adequate aerodynamic modeling which captures nonlinear unsteady variation of aerodynamic loads in these flight regimes. Two novel models for unsteady aerodynamics at low and high subsonic Mach numbers are described. These models and prototyping control laws are used for closed loop computational analysis. The computational methodology of clearing flight control laws for flight envelope expansion of a Generic Tailless Aircraft (GTA) is addresse

Aerodynamic model of transport airplane in extended envelope for simulation of upset recovery

The paper presents the aerodynamic model in extended flight envelope for a generic airliner with under wing engines and conventional tail developed within the EU Framework Programme (FP7) research project Simulation of Upset Recovery in Aviation (SUPRA) (www.supra.aero). The SUPRA aerodynamic model is covering angles of attack beyond stall and speeds from take-off to cruise flight. The aerodynamic model in extended flight envelope developed for piloted simulation of upset prevention and recovery has been successfully validated by a number of expert pilots

Characterization of the Genomic Xist Locus in Rodents Reveals Conservation of Overall Gene Structure and Tandem Repeats but Rapid Evolution of Unique Sequence

The Xist locus plays a central role in the regulation of X chromosome inactivation in mammals, although its exact mode of action remains to be elucidated. Evolutionary studies are important in identifying conserved genomic regions and defining their possible function. Here we report cloning, sequence analysis, and detailed characterization of the Xist gene from four closely related species of common vole (field mouse), Microtus arvalis. Our analysis reveals that there is overall conservation of Xist gene structure both between different vole species and relative to mouse and human Xist/XIST. Within transcribed sequence, there is significant conservation over five short regions of unique sequence and also over Xist-specific tandem repeats. The majority of unique sequences, however, are evolving at an unexpectedly high rate. This is also evident from analysis of flanking sequences, which reveals a very high rate of rearrangement and invasion of dispersed repeats. We discuss these results in the context of Xist gene function and evolution. [The sequence data described in this paper have been submitted to the GenBank data library under accession nos. AJ310127–AJ310130 and AJ311670.

Identification of the Elemental Composition of Granulated Blast Furnace Slag by FTIR-Spectroscopy and Chemometrics

Blast furnace slag is a key large-tonnage waste product of metallurgical production, which is considered to be a promising alternative material in construction. In order to determine the scope of potential use of slag as a marketable product, it is necessary to study its structure and composition, which is determined by means of modern analytical instrumental methods. This paper analyzes the application of Fourier transform infrared spectroscopy (FTIR) and chemometrics methods to develop calibration models for identifying pelletized slag by elemental composition. In a comparative analysis of FTIR-spectra of slag the characteristic frequencies of absorption bands responsible for the content of calcite, silicates and aluminosilicates in the composition of samples were determined. Multivariate regression methods (principal components regression, partial least squares regression) and data of elemental composition results by EDX method were used to develop calibration models for determining elemental composition of granulated blast furnace slag. Using the developed PLS models with high performance (R2 from 0.91 to 0.96 for different components), the prediction of the elemental composition (Ca, Si, O, Mg) of the test sample was carried out and a low deviation of the prediction in contrast to the EDX reference data was obtained. The use of PLS calibration models for rapid and nondestructive determination of the quantitative content of components of the composition of granulated blast furnace slag has been proposed

The search for \ub5+ \u2192 e+\u3b3 with 10 1214 sensitivity: The upgrade of the meg experiment

The MEG experiment took data at the Paul Scherrer Institute in the years 2009\u20132013 to test the violation of the lepton flavor conservation law, which originates from an accidental symmetry that the Standard Model of elementary particle physics has, and published the most stringent limit on the charged lepton flavor violating decay \ub5+ \u2192 e+\u3b3: BR(\ub5+ \u2192 e+\u3b3) < 4.2 7 10 1213 at 90% confidence level. The MEG detector has been upgraded in order to reach a sensitivity of 6 7 10 1214 . The basic principle of MEG II is to achieve the highest possible sensitivity using the full muon beam intensity at the Paul Scherrer Institute (7 7 107 muons/s) with an upgraded detector. The main improvements are better rate capability of all sub-detectors and improved resolutions while keeping the same detector concept. In this paper, we present the current status of the preparation, integration and commissioning of the MEG II detector in the recent engineering runs