Continuous active T-gate travelling-wave transistor

In the letter experimental results are presented which show that a continuous active gate travelling-wave transistor (TWT) can be used for medium power applications in a wide bandwidth. To reduce the gate resistance, a T-gate configuration has been chosen. This allows one to extend the frequency bandwidth of such a device. Simulations have been performed using small- and large-signal models taking in addition the parasitic capacitances into account. A distributed Schottky diode has been used to adjust the phase synchronisation and therefore to achieve flat gain.<>     

Phase-sensitive spatially-modulated surface plasmon resonance polarimetry for detection of biomolecular interactions

We here describe a scheme of spatially modulated surface plasmon resonance (SPR) polarimetry that enables to combine ultra-high phase sensitivity with good signal-to-noise background. The proposed approach uses spatial modulation of s-polarized component by birefringent elements and the extraction of phase-polarization information by Fourier-transform methods. This scheme was tested for monitoring the interactions between an antibody and its biological partner. Our experimental data, collected by amplitude-sensitive and phase-sensitive polarimetry demonstrate that the latter scheme provides at least one order of magnitude improvement in terms of detection limit.     

Methylphenidate and baseball playing in ADHD children: Who's on first?

The effects of 0.3 and 0.6 mg/kg methylphenidate were analyzed in a double-blind, placebo-controlled, cross-over study in which 17 boys (ages 7.8–9.9 yrs) with attention deficit hyperactivity disorder (ADHD) played in baseball games. Drug effects were evaluated on children's attention during the game, as indictated by their on-task behavior on the field and their ability to answer questions about the status of the game at all times. Judgment during batting, batting skill during the game, and performance on skill drills prior to the game were also assessed as a function of medication. Results revealed that methylphenidate had a beneficial effect on attending during the game. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Circuit coupling method applied to bulk superconductors

This paper presents a new finite-element method for including a bulk superconductor in an electrical circuit. The method solves simultaneously the finite-element equations of A/spl psi/ formulation and the circuit equations. At the same time, a power law defines the superconducting properties. The method then compares the classical homogeneous model of a Bi-2223 tape to a multifilament model. The results of a simulation of conductors carrying alternative current while subjected to an external ac field are presented.     

A generalized method for characterizing elastic anisotropy in solid living tissues

The microstructure of cortical bone may exhibit either transverse isotropic or orthotropic symmetry, thus requiring either five or nine independent elastic stiffness coefficients (or compliances), respectively, to describe its elastic anisotropy. Our previous analysis to describe this anisotropy in terms of two scalar quantities for the transverse isotropic case is extended here to include orthotropic symmetry. The new results for orthotropic symmetry are compared with previous calculations using the transverse isotropic analysis on the same sets of anisotropic elastic constants for bone, determined either by mechanical or by ultrasonic experiments. In addition, the orthotropic calculation has been applied to full sets of orthotropic elastic stiffness coefficients of a large variety of wood species. Although having some resemblance to plexiform bone in microstructural organization, there is a dramatic difference in both the shear and the compressive elastic anisotropy between the two materials: wood is at least one order of magnitude more anisotropic than bone.     

Encoding context and retrieval conditions as determinants of the effects of natural category size.

Studying a familiar word activates its associates in long-term memory. In the present experiments we manipulated the number of associates activated by words studied in the presence of unrelated context words, meaningfully related context words, or in the absence of modifying context words. Memory was tested by either cued or free recall. The results showed that the number of directly activated associates can facilitate, have no effect, or disrupt recall for studied words. The direction and magnitude of the effects of number of activated associates is shown to be determined by the encoding/retrieval context. Implications for the distinction between episodic and semantic memory are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

AC losses in superconducting solenoids

This paper presents an analytical model to determine AC losses in monolayer and multilayer superconducting solenoids. The case of a transformer with several coils is also presented. This model is based on an infinite cylindrical geometry and the Bean model. Under this assumption, the electromagnetic variables distributions are determined and then instantaneous losses are simply calculated. For a monolayer coil the mean losses are given too. Then, analytical results are compared to numerical results performed with previous development in Flux3D (finite elements software). Finally, a comparison with measurements on a two-layer coil is presented.     

Ancient Analogues of Modern Cement: Calcium Hydrosilicates in Mortars and Concretes from Gallo–Roman Thermal Baths of Western France

The long-term durability of cementbased materials over periods of time not directly accessible to laboratory experiments has to be thoroughly assessed to guarantee the safety of a radioactive waste repository. In this work, archaeological mortars and concretes have been studied to check whether their use as analogues of actual technological cements used for waste disposal is possible. Samples of mortar and concrete have been collected from several Gallo-Roman thermae of western France; they were examined as petrographically thin sections with optical microscopy and were analyzed by X-ray diffraction of microsamples (10⁻³ mg) and by electron probe microanalysis. The masonry cement appears to be entirely carbonated with large voids and fissures. In contrast, the use of lime with additional crushed brick or tile for the bath structure concrete and coating mortar induced pozzuolanic reactions. Despite the fact that the matrices are essentially composed of calcium carbonate, calcium aluminosilicates with compositions close to those of hydrogrossular, hydrated calcium silicates with composition and a structure comparable with those of calcium hydrosilicate formed in modern cement, and ettringite deposits in voids of concretes could also be identified. It is suggestea that these ancient artifacts can help identify very slow processes that rule cement alteration over long periods of time. The artifacts may be considered as possible analogues of present-day materials whenever sufficient care is taken in interpreting and extrapolating data.     

马克·加格布斯:美式风情

在这个大选之年,关于美国是什么,不是什么的话题已经很多.对于作家、音乐家、艺术家、时装设计师,尤其是那些喜欢从各种复杂、矛盾的角度来思考美国生活和历史的人来说,这个大选就是一处可以催生无数话题的肥沃土壤.     

Novel TTLL5 Variants Associated with Cone-Rod Dystrophy and Early-Onset Severe Retinal Dystrophy

Variants of the TTLL5 gene, which encodes tubulin tyrosine ligase-like family member five, are a rare cause of cone dystrophy (COD) or cone-rod dystrophy (CORD). To date, only a few TTLL5 patients have been clinically and genetically described. In this study, we report five patients harbouring biallelic variants of TTLL5. Four adult patients presented either COD or CORD with onset in the late teenage years. The youngest patient had a phenotype of early onset severe retinal dystrophy (EOSRD). Genetic analysis was performed by targeted next generation sequencing of gene panels and assessment of copy number variants (CNV). We identified eight variants, of which six were novel, including two large multiexon deletions in patients with COD or CORD, while the EOSRD patient harboured the novel homozygous p.(Trp640*) variant and three distinct USH2A variants, which might explain the observed rod involvement. Our study highlights the role of TTLL5 in COD/CORD and the importance of large deletions. These findings suggest that COD or CORD patients lacking variants in known genes may harbour CNVs to be discovered in TTLL5, previously undetected by classical sequencing methods. In addition, variable phenotypes in TTLL5-associated patients might be due to the presence of additional gene defects.