A Hybrid Micromachined High -Q Cavity Resonator at 5.8 GHz

A novel hybrid micromachined resonator with high quality factor and small size at 5.8GHz is presented. The design of the resonator is based on a micromachined cavity filled with a high dielectric constant material. Energy is coupled into the cavity from input and output microstrip lines via slots. It is shown experimentally that the limiting factor in achieving a higher Q with the given dielectric materials is the dielectric loss. This resonator provides a low cost, minimum size and compact solution for the fabrication of planar, narrow-band filters and diplexers in modern wireless communication systems.

Genetic evaluation of horses based on ranks in competitions

A method is presented for analysing horse performance recorded as a series of ranks obtained in races or competitions. The model is based on the assumption of the existence of an underlying normal variable. Then the rank of an animal is merely the phenotypic expression of the value of this underlying variable relative to that of the other horses entering the same competition. The breeding values of the animals are estimated as the mode of the a posteriori density of the data in a Bayesian context. Calculation of this mode entails solving a non-linear system by iteration. An example involving the results of races of 2-yr-old French trotters in 1986 is given. Practical computing methods are presented and discussed.Cet article présente une méthode d’analyse de performances enregistrées sous la forme de classements obtenus dans des confrontations restreintes et variables (courses ou concours). Le modèle postule d’existence d’une variable normale sous-jacente. Le classement d’un cheval est alors simplement d’expression phénotypique de la valeur de cette variable sous-jacente relativement à celles des autres animaux participant à la même épreuve. Les valeurs génétiques des animaux sont estimées à partir du mode de la densité a posteriori des données dans un contexte bayésien. Le calcul de ce mode amène à la résolution d’un système non linéaire par itérations. Un exemple d’application est réalisé sur les résultats des courses des chevaux Trotteurs Français de 2 ans en 1986. Des méthodes de calculs pratiques sont proposées et discutées

Power-law dependence of the angular momentum transition fields in few-electron quantum dots

We show that the critical magnetic fields at which a few-electron quantum dot undergoes transitions between successive values of its angular momentum (M), for large M values follow a very simple power-law dependence on the effective inter-electron interaction strength. We obtain this power law analytically from a quasi-classical treatment and demonstrate its nearly-universal validity by comparison with the results of exact diagonalization.Comment: Uses RevTeX4, 6 figures included in the tex

Re-entrant pinning of Wigner molecules in a magnetic field due to a Coulomb impurity

Pinning of magnetic-field induced Wigner molecules (WMs) confined in parabolic two-dimensional quantum dots by a charged defect is studied by an exact diagonalization approach. We found a re-entrant pinning of the WMs as function of the magnetic field, a magnetic field induced re-orientation of the WMs and a qualitatively different pinning behaviour in the presence of a positive and negative Coulomb impurity

OTUB1 triggers lung cancer development by inhibiting RAS monoubiquitination

Activation of the RAS oncogenic pathway, frequently ensuing from mutations in RAS genes, is a common event in human cancer. Recent reports demonstrate that reversible ubiquitination of RAS GTPases dramatically affects their activity, suggesting that enzymes involved in regulating RAS ubiquitination may contribute to malignant transformation. Here, we identified the de-ubiquitinase OTUB1 as a negative regulator of RAS mono- and di-ubiquitination. OTUB1 inhibits RAS ubiquitination independently of its catalytic activity resulting in sequestration of RAS on the plasma membrane. OTUB1 promotes RAS activation and tumorigenesis in wild-type RAS cells. An increase of OTUB1 expression is commonly observed in non-small-cell lung carcinomas harboring wild-type KRAS and is associated with increased levels of ERK1/2 phosphorylation, high Ki67 score, and poorer patient survival. Our results strongly indicate that dysregulation of RAS ubiquitination represents an alternative mechanism of RAS activation during lung cancer development

Model for the on-site matrix elements of the tight-binding hamiltonian of a strained crystal: Application to silicon, germanium and their alloys

We discuss a model for the on-site matrix elements of the sp3d5s* tight-binding hamiltonian of a strained diamond or zinc-blende crystal or nanostructure. This model features on-site, off-diagonal couplings between the s, p and d orbitals, and is able to reproduce the effects of arbitrary strains on the band energies and effective masses in the full Brillouin zone. It introduces only a few additional parameters and is free from any ambiguities that might arise from the definition of the macroscopic strains as a function of the atomic positions. We apply this model to silicon, germanium and their alloys as an illustration. In particular, we make a detailed comparison of tight-binding and ab initio data on strained Si, Ge and SiGe.Comment: Submitted to Phys. Rev.