Identification of a calcium channel modulator using a high throughput yeast two-hybrid screen

The interaction of the N-type calcium channel beta3 subunit with the alpha1B subunit alters the activation/inactivation kinetics and the maximal conductance of the channel. The defined protein-protein interaction of the human alpha1B and beta3 subunits provides a target for small-molecule modulation of N-type channel activity. We describe a high throughput screen based on a counterselection yeast two-hybrid assay, which was used to identify small molecules that disrupt alpha1B-beta3 subunit interactions and inhibit N-type calcium channel activity. These small molecules may be a new class of calcium channel antagonists with therapeutic potential.     

Oxidation Behavior of a Si-C-O-Fiber-Reinforced Magnesium Aluminosilicate

The oxidation behavior of a Si-C-O-fiber-reinforced magnesium aluminosilicate has been investigated in the temperature range 1000°-1200°C. Parabolic weight gain, together with other experimental observations, has suggested that the oxidation process was controlled by the outward diffusion of carbon monoxide gas. The matrix and fibers reacted to form enstatite and forsterite. During the initial stages of oxidation, an interlayer containing a mixture of silica and turbostratic carbon was formed. This interlayer was modified progressively over time to create interface morphologies near the surface and near the center of the oxidized samples that were different from one another. A mechanism explaining the morphological evolution of the fiber-matrix interfaces has been proposed.     

Are financial incentives related to performance? A meta-analytic review of empirical research.

The relationship of financial incentives to performance quality and quantity is cumulated over 39 studies containing 47 relationships. Financial incentives were not related to performance quality but had a corrected correlation of .34 with performance quantity. Setting (laboratory, field, experimental simulation) and theoretical framework moderated the relationship, but task type did not. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Collapse load analysis of square and rectangular tubes subjected to transverse in-plane loading

Experiments to determine the collapse load of aluminum and mild steel tubes, of square and rectangular cross-sections, between parallel rigid platens were carried out in an Instron machine. A two stage analysis for the collapse of these tubes was carried out by considering the out-of-straightness of arms, corner radius, friction between the platens and the specimen and stability of the vertical arms. Results thus obtained compare well with experiments.     

The mechanical properties of the superplastic AI- 33 Pct Cu eutectic alloy

Experiments were conducted to determine the mechanical properties of the superplastic Al-33 Pct Cu eutectic alloy at temperatures from 673 to 723 K. Specimens were tested in a well-annealed condition and there was no evidence for grain growth even at the lowest experimental strain rate of 6.7 × 1(10^-7 s^-1. It is shown that the stress-strain curves rapidly attain a steady-state value at strain rates below ′10^-4 s^-1, and there is a sigmoidal relationship between stress and strain rate which may be obtained using several different testing procedures. The maximum elongation to failure recorded in these experiments was 1475 Pct at an initial strain rate of 1.3 × 10^-5 s^-1. The true activation energy for plastic flow is 175 ±11 kJ mol^-1 in the superplastic region II, but it increases to 299 ± 18 kJ mol^-1 at low strain rates in region I. The exponent of the inverse grain size is 2.1 ±0.3 in region II. These results show that, when the grains size is stable, there is a genuine region I in the Al-33 Pct Cu alloy at initial strain rates below ∼10^-5 s^-1.     

A general formulation for the nonlinear dynamics and control of orbiting flexible structures

A relatively general Lagrangian formulation for studying the dynamics of a large class of spacecraft characterized by interconnected flexible members forming a tree topology, is presented. Methodology and development of the computer code suitable for parametric dynamical study and control are briefly outlined. Versatility of the general formulation is demonstrated through dynamics studies of the Permanently Manned Configuration (PMC) of the proposed Space Station Freedom and the slewing dynamics and control of the two-link Mobile Servicing System (MSS) aboard Freedom. The PMC study indicates the effect of flexibility cannot be overlooked. Even a small disturbance on the main or stinger can result in unacceptable magnitudes of velocity and acceleration. The MSS study compares the system response subjected to the InPlane (IP) and Out-of-Plane (OP) maneuvers. Results indicate that, without control, the OP maneuver excites large yaw motion of the Space Station. Consequently, the OP maneuver has a large pointing error. Nonlinear control, based on the Feedback Linearization Technique, appears promising. By controlling the librational motion of the station, the performance of the OP maneuver improves significantly.     

An evaluation of the optical fiber beam as a force sensor

The present study reports the use of an intensity based plastic optical fiber (POF) as a force sensor. Different materials for beam, such as spring steel and mild steel, are used to evaluate the performance of the force sensor during macro-bending. The POF is surface bonded to a beam and subjected to force. The system relies on monitoring the light intensity, as the POF is subjected to transversal loading conditions. Experimentally obtained output of POF which could be measured with negligible hysteresis is compared with finite element analysis in the range between 0.0098 N to 19.613 N. The reproducibility of the sensor is observed in the limit of ±1%. The finding of this study highlights the potential use of POF sensors for various force sensing applications.     

A Huge Effect of Weak dc Electrical Fields on Grain Growth in Zirconia

We show that the application of a modest dc electrical field, about 4 V/cm, can significantly reduce grain growth in yttria-stabilized polycrystalline zirconia. These measurements were made by annealing samples, for 10 h at 1300°C, with and without an electrical field. The finding adds a new dimension to the role of applied electrical fields in sintering and superplasticity, phenomena that are critical to the net-shape processing of ceramics. Grain-growth retardation will considerably enhance the rates of sintering and superplasticity, leading to significant energy efficiencies in the processing of ceramics.     

Software defined vehicular networks: A comprehensive review

The recent breakthroughs in the automobile industries and telecommunication technologies along with the exceptional multimodal mobility services brought focus on intelligent transportation system (ITS), of which vehicular ad hoc networks (VANETs) gain much more attention. The distinctive features of software‐defined networking (SDN) leverages the vehicular networks by its state of the centralized art having a comprehensive view of the network. Its potential to bring the flexibility, programmability and other extensive advancements to vehicular networks has set the stage for a novel networking paradigm termed as software‐defined vehicular networks (SDVNs). Many researchers have demonstrated the SDN‐based VANETs with the various configuration of the SDN components in VANET architecture. However, a compilation of the work on the SDN‐based VANET system as a whole, incorporating its architecture, use‐cases, and opportunities, is still inadequate. We start with the summary of the recent studies that exist on the SDVNs, followed by the comprehensive explanation of its components. Next, we present the taxonomy of SDVN based on the architecture modes, protocols, access technologies, and opportunities with trending technologies. Finally, we highlight the challenges, open research issues, and future research directions.