A G protein gamma subunit-like domain shared between RGS11 and other RGS proteins specifies binding to Gbeta5 subunits

Regulators of G protein signaling (RGS) proteins act as GTPase-activating proteins (GAPs) toward the alpha subunits of heterotrimeric, signal-transducing G proteins. RGS11 contains a G protein gamma subunit-like (GGL) domain between its Dishevelled/Egl-10/Pleckstrin and RGS domains. GGL domains are also found in RGS6, RGS7, RGS9, and the Caenorhabditis elegans protein EGL-10. Coexpression of RGS11 with different Gbeta subunits reveals specific interaction between RGS11 and Gbeta5. The expression of mRNA for RGS11 and Gbeta5 in human tissues overlaps. The Gbeta5/RGS11 heterodimer acts as a GAP on Galphao, apparently selectively. RGS proteins that contain GGL domains appear to act as GAPs for Galpha proteins and form complexes with specific Gbeta subunits, adding to the combinatorial complexity of G protein-mediated signaling pathways.     

The effects of knee reconstruction on combined anterior cruciate ligament and anterolateral capsular deficiencies

We tested the effect of intraarticular reconstructions of the anterior cruciate ligament alone and in combination with extraarticular reconstructions in 10 cadaveric knees. These knees had anterior cruciate ligament deficiency alone or in combination with anterolateral capsuloligamentous deficiencies. In the knees with combined injury, intraarticular reconstruction returned anterior stability to levels not significantly different from levels found for the knees deficient in the anterior cruciate ligament alone and treated with this procedure. After intraarticular reconstruction, rotational stability of the knee with combined injuries failed to return to the levels seen in the knee with isolated anterior cruciate ligament deficiencies that underwent the same treatment. When a tenodesis with either 0 N or 22 N of tension was added to the intraarticular reconstruction in the knee with combined injuries, we found that excessive internal rotation significantly decreased at all angles of flexion, except at full extension with 0 N of tension. In addition, the extraarticular reconstruction with 22 N of tension in the tenodesis overconstrained the knee in internal rotation between 30 degrees and 90 degrees of knee flexion. The tenodesis with 0 N of tension overconstrained the knee at only 60 degrees and 90 degrees of flexion. These results suggest extraarticular reconstruction as an adjunct to the intraarticular operation for the knee with anterior cruciate ligament and anterolateral structural injuries. The results also suggest that the surgeon can affect anterior and rotational laxity by adjusting the tension in the tenodesis.     

Nonhomogeneity of light modulation by PLZT retardation plates

Nonhomogeneity of light modulation by PLZT retardation plates - temporal due to the secondary electrooptic effect, and spatial due to the interference of directly transmitted and reflected light beams in birefringent substance has been discussed.     

Heat-shrinkable films based on polyolefin waste

Polyethylene wastes (low-density polyethylene, high-density polyethylene and their binary blends) were subjected to high-energy radiation, using a ⁶⁰Co gamma radiation source. The crosslinked materials thus obtained were processed to heatshrinkable films. Tensile strength could be sharply improved by increasing the dose up to 20 Mrad, simultaneously increasing the elongation at break of the most degraded PE waste. An increase of the degree of compatibility of LDPE and HDPE waste was also observed. All samples examined exhibit a “memory effect” after drawing at 130°C and cooling under tension followed by further heating under relaxed conditions. The value of shrinkage depended on the degree of degradation of the PE waste and on the irradiation dose.     

Research of the physical-chemical properties of adhesive radiation-modified thermosetting materials based on polyolefins and their composites

The present paper surveys the investigation results of the adhesive behavior with steel of different polyethylenes (LDPE, HDPE) irradiated with γ-radiation in vacuum, oxygen, and air, using rheological, optical, thermomechanical and other methods. To study the adhesive contact, the technological parameters applicable to thermosetting polymer material were taken into consideration. The results show the suitable methods in order to obtain thermosetting polymer materials with improved adhesive and thermomechanical properties.     

Levitated Liquid Dynamics in Reduced Gravity and Gravity-Compensating Magnetic Fields

Dynamic models are used to investigate the behavior of liquid droplets suspended in alternating current and direct current magnetic fields in microgravity and in various configurations providing conditions similar to microgravity. The realistic magnetic fields of solenoidal coils are used for the modeling experiments with electrically conducting (liquid silicon or metal) droplets. At high values of magnetic field, some oscillation modes are damped quickly, while others are modified with a considerable shift of the oscillating droplet frequencies and the damping constants from the nonmagnetic case. On a larger scale, the models are used to investigate the melting and heating process of reactive materials. It is demonstrated how 1?kg of liquid titanium in a traditional ??cold?? crucible-type furnace can be fully levitated without contact to wall to achieve high superheat of the melt.     

Thermomechanical properties of radiation-modified blends of polyethylene with liquid crystalline copolyester

The results of investigation of gamma irradiated blends of high-density polyethylene (PE) with thermotropic polymer liquid crystal (PLC) are presented. The PLC used was a copolyester of 40% poly(ethylene terephthalate) with 60% p-(hydroxy-benzoic acid). The PLC content in the blends was 0, 5, and 10 wt%. The constituents were blended with the use of a single screw extruder. The specimens were prepared by compression molding. The irradiation of the samples was performed by a Co⁶⁰ γ-radiation source in inert atmosphere (argon) up to absorbed relatively low doses (up to 200 kGy; 1 Mrad = 10 kGy). The morphological, thermal, and mechanical properties were investigated for irradiated and unirradiated samples. The influence of gamma irradiation and addition of PLC on the temperature dependence of the elastic modulus as well as the effect of a “form memory” of the materials examined are discussed. It was found that an addition of the PLC affects substantially the stress-strain relationship in tension at temperatures above the melting point of PE for the irradiated samples. The features of thermomechanical behavior of the PE + PLC blends, previously irradiated and oriented, at isometrical heating and cooling were also established. The results obtained testify that the addition of PLC to PE makes it possible to improve considerably the thermosetting properties of the heat-shrinkable polymeric products.     

Polyisoprene-nanostructured carbon composite (PNCC) organic solvent vapour sensitivity and repeatability

In this paper highly structured carbon black (HSCB) dispersion method effect on polyisoprene-nanostructured carbon composite (PNCC) organic solvent vapour (OSV) sensitivity is presented. PNCC has been produced using two different HSCB dispersion techniques: (1) dry method: the HSCB dispersed in polyisoprene mixing ingredients by cold rolling and (2) wet method: the HSCB dispersed in chloroform by ultrasonic homogenizer and mixed with solution of rubber in chloroform by magnetic stirring. The sensitivity to OSV of the obtained PNCC is tested by holding the samples in vapour of toluene or ethyl acetate and measuring in situ electrical resistance, mass, and length of the sample. Obtained results indicate two mechanisms of the change of electrical resistance in PNCC. Repeatability of the response of PNCC is tested in case of toluene vapour.     

Software merge: Combining changes to decompositions

Computer aid for software evolution is needed for more effective software development, particularly in contexts where changes to large systems must be made rapidly. This paper addresses computer aid for the evolution of requirements models and high level software designs. We present an improved method for automatically merging changes to software designs expressed via annotated dataflow diagrams and hierarchical decomposition. This improvement addresses the structure of the design as well as the system behavior the design implies. We also present an improved method for automatically reporting and repairing conflicts between structural changes. These methods can be applied to the informal dataflow diagrams commonly used in requirements modeling and software design as well as to the more specific executable design representations used in the computer-aided prototyping system CAPS.