Post-translational modifications of alpha5beta1 integrin by glycosaminoglycan chains. The alpha5beta1 integrin is a facultative proteoglycan

Cell-fibronectin interactions, mediated through several different receptors, have been implicated in a wide variety of cellular properties. Among the cell surface receptors for fibronectin, integrins are the best characterized, particularly the prototype alpha5beta1 integrin. Using [125I]iodine cell surface labeling or metabolic radiolabeling with sodium [35S]sulfate, we identified alpha5beta1 integrin as the only sulfated integrin among beta1 integrin heterodimers expressed by the human melanoma cell line Mel-85. This facultative sulfation was confirmed not only by immunoprecipitation reactions using specific monoclonal antibodies but also by fibronectin affinity chromatography, two-dimensional electrophoresis, and chemical reduction. The covalent nature of alpha5beta1 integrin sulfation was evidenced by its resistance to treatments with high ionic, chaotrophic, and denaturing agents such as 4 M NaCl, 4 M MgCl2, 8 M urea, and 6 M guanidine HCl. Based on deglycosylation procedures as chemical beta-elimination, proteinase K digestion, and susceptibility to glycosaminoglycan lyases (chondroitinase ABC and heparitinases I and II), it was demonstrated that the alpha5beta1 heterodimer and alpha5 and beta1 integrin subunits were proteoglycans. The importance of alpha5beta1 sulfation was strengthened by the finding that this molecule is also sulfated in MG-63 (human osteosarcoma) and HCT-8 (human colon adenocarcinoma) cells.     

High-temperature low-cycle fatigue of an iron-base oxide-dispersion strengthened alloy: Grain structure effects and lifetime correlations

The high-temperature low-cycle fatigue (LCF) behavior of the new oxide-dispersion strengthened (ODS) alloy PM 2000 is investigated at 1050 °C using symmetrical and asymmetrical wave shapes. The grain structures range from “single crystals” (grain size of several centimeters) to polycrystals with an average grain size of less than 30 μm. It is found that the grain structure determines the fracture path but cannot be correlated with cyclic lifetimes. Instead, lifetime can be predicted on the basis of the different Young’s moduli of the grain structures and correlates with the reciprocal of Young’s modulus. A normalization is proposed that condenses all lifetime data, which span two orders of magnitude, into a narrow scatterband.     

Clonidine antagonizes the aversive effects of opiate withdrawal and the rewarding effects of morphine only in opiate withdrawn rats.

The researchers asked whether clonidine, an α?-noradrenergic agonist, would block selectively the motivational effects of opiate withdrawal and whether clonidine's effects would respect the boundary between nondeprived and deprived motivational states. In a place conditioning paradigm, clonidine (0.05 mg/kg ip) blocked the rewarding effects of morphine in opiate-withdrawn rats (as well as the aversive properties of withdrawal itself), but did not affect morphine place preferences (2 and 20 mg/kg) in drug-naive rats. Furthermore, clonidine blocked the acquisition of morphine (15 mg/kg), but not LiCI (15 mg/kg), conditioned taste aversions in water-deprived rats. The results suggest that the motivational system activated in deprived animals includes dopaminergic and noradrenergic components that are in series with each other. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Stimulation of heparan sulfate proteoglycan synthesis and secretion during G1 phase induced by growth factors and PMA

Pulsatile tinnitus is a disorder that can be extremely disabling. Nonetheless, it has not been well-researched in the fields of psychology or behavioral therapy. This article describes the evaluation and behavioral treatment of a gentleman with pulsatile tinnitus. The evaluation included polygraphic assessment of vasomotor and electromyographic function both before and after treatment. The results show that the combination of lifestyle modifications and specific behavioral interventions were successful in modifying not only self-report indices of functioning, but also the underlying physiology related to the disorder. The potential role of the various treatment components and the value of including polygraphic assessment for informing treatment and evaluating outcome are discussed.     

Long term ageing of polyamide 6 and polyamide 6 reinforced with 30% of glass fibers: temperature effect

Because the prediction of the durability of polyamide materials is a very important issue for designers and users, the effect of environment conditions on their mechanical properties is an active field of research. For this reason this experimental investigation was conducted in order to study the effect of temperature on long term ageing of polyamide 6 (PA6) and polyamide 6 reinforced with 30 wt% of glass fibers (PA6GF30). Ageing was realized in distilled water (pH?≈?6; 100% RH) at 30 °C, 50 °C, 70 °C and 90 °C for up to 80 days. Results highlighted the impact of ageing temperature on both conditioned materials. Thus, several surface damages such as crazing and yellowness were recorded especially at high temperatures indicating the materials degradation. These structure changes were induced by the combined effects of water and temperature. As the water diffuses within the polymer, the glass transition temperature T_g drops progressively with ageing temperature to reach the lowest value for samples aged at 90 °C for both tested materials. This tendency was also observed for Young’s modulus, tensile strength and the elongation at break. Thus, a significant loss in stiffness and strength of both materials was recorded as a function of conditioning temperature. This loss of mechanical properties is mainly caused by hydrolysis process and/or interfacial debonding. The appearance of this irreversible phenomenon rises with ageing temperature. Moreover, contrarily to PA6GF30, the temperature effect was also pointed out on SEM observations of PA6 samples. Thus, the hygrothermal ageing induces a change in the mode of fracture from ductile to moderate brittle one according to the ageing temperature. Accordingly, it seems that the ageing temperature has a great effect on the severity of damage of tested materials after long term immersion.     

Exact Learning of Formulas in Parallel

We investigate the parallel complexity of learning formulas from membership and equivalence queries. We show that many restricted classes of boolean functions cannot be efficiently learned in parallel with a polynomial number of processors.     

Phase noise impact on the performance of contention resolution slotted random access schemes

Cost‐effective satellite terminals (STs) that are designed for a large scale deployment in the Internet of things (IoT) applications are constrained by consumer‐grade local oscillators (LOs) to lower the costs, on the one hand, and by limited equivalent isotropic radiated power (EIRP) due to limited peak transmit power and/or low antenna gain, on the other hand. To close the link budget with the low EIRP constraint, STs can resort to adopting robust forward error correcting (FEC) schemes and/or limiting the transmission baud rate, hence increasing the link margin with respect to the required receiver threshold. In general, the LOs at the terminal side are responsible for injecting multiplicative phase distortions to the transmitted signal, known as phase noise (PN). The PN caused by low‐cost LOs could be significant, especially for low baud rates, thus affecting the demodulator performance. Random access (RA) techniques are particularly encouraged on the return link in networks with low‐cost terminals and bursty/low‐duty cycle types of traffic. The state‐of‐the‐art time‐slotted RA techniques are often evaluated considering high EIRP at the terminal side and high baud rates. This paper investigates the impact of the PN in time‐slotted RA techniques and optimizes different carrier phase estimation (CPE) algorithms. Furthermore, it evaluates the impact of CPE errors on RA performance for a wide range of baud rates and typical STs phase noise masks.     

Adaptive sliding mode control for a general nonlinear multicompartment lung model with input pressure and rate saturation constraints

In this article, we develop an output feedback adaptive sliding mode controller for a general multicompartment lung mechanics model with nonlinear resistance and compliance respiratory parameters. Specifically, for a given clinically plausible reference volume pattern, we develop an adaptive sliding mode controller that accounts for input pressure and rate saturation constraints to automatically adjust the applied input pressure by the mechanical ventilator so that the total lung volume tracks the given reference pattern. The pressure due to lung muscle activity is also considered in the controller design. A Lyapunov‐based approach is presented to show convergence of the closed‐loop system, and the proposed control framework is applied to a two‐compartment lung model to show the efficacy of the proposed control method. Copyright © 2015 John Wiley & Sons, Ltd.