Article reporting that PAK2, a member of the Rho family of GTPase-dependent kinases, regulates isometric tension development and myosin II RLC phosphorylation in saponin permeabilized endothelial monolayers. The results demonstrate that PAK2 can directly phosphorylate MLCK, inhibiting its activity and limiting the development of isometric tension.

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In 1998, we started the R&D program for the development of high performance planar solid oxide fuel cells (SOFCs) at Lawrence Livermore National Laboratory. The long-term goal of the project is to develop a planar SOFC system running directly on natural gas. The short-term goal is to develop low cost manufacturing techniques and to demonstrate stack power density greater than 1 W/cm2 at 800 C. The high power density will make possible to lower fuel cell operating temperature, thus enabling the use of cheaper materials as well as the direct oxidation of natural gas. This paper summarizes the technical status of the fabrication and electrochemical testings of single cells and stacks.

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Gathering from 33 countries around the world, 408 registrants and a number of local drop-in participants descended on the Clark Kerr Campus of the University of California, Berkeley, from Monday, August 7 through Saturday, August 12, 2000 for the Eighth International Conference on Electronic Structure and Spectroscopy (ICESS8). At the conference, participants benefited from an extensive scientific program comprising more than 100 oral presentations (plenary lectures and invited and contributed talks) and 330 poster presentations, as well as ample time for socializing and a tour of the Advanced Light Source (ALS) at the nearby Lawrence Berkeley National Laboratory.

The authors examine the transient residual thermal signal resulting from an underground nuclear test (buried below the water table) and its potential to affect local groundwater flow and radionuclide migration in a saturated, fractured, volcanic aquifer system. Thermal profiles measured in a drillback hole between 154 days and 6.5 years after the test have been used to calibrate a non-isothermal model of fluid flow. In this process, they have estimated the magnitude and relative changes in permeability, porosity and fracture density between different portions of the disturbed and undisturbed geologic medium surrounding the test location. The relative impacts of buoyancy forces (arising from the thermal residual of the test and the background geothermal gradient) and horizontal pressure gradients on the post-test flow system are better understood. A transient particle/streamline model of contaminant transport is used to visualize streamlines and streaklines of the flow field and to examine the migration of non-reactive radionuclides. Sensitivity analyses are performed to understand the effects of local and sub-regional geologic features, and the effects of fractured zones on the movement of groundwater and thermal energy. Conclusions regarding the overall effect of the thermal regime on the residence times and fluxes of radionuclides out of the …

Many cancers, including prostate, breast and lung express parathyroid hormone related protein (PTHrP). Despite the common tumor overexpression of PTHrP, serum levels of PTHrP are not commonly elevated in affected patients. They postulate that the reasons for the discrepancy between tissue and serum measurements of PTHrP are the inadequate sensitivity and specificity of current PTHrP serum assays. To improve the clinical value of PTHrP serum assays for the cancer patient, they are developing a new generation of novel and ultrasensitive PTHrP serum immunoassays based on immunoaffinity purification, nanospray liquid chromatography tandem mass spectrometry (LC/MS/MS) and accelerator mass spectrometry (AMS).

The propagation of optical Code Division Multiple Access (CDMA) signals was studied by computer simulation. Group velocity dispersion produces the worst impairment. With dispersion management, the decoder successfully recovers the signals, even in the presence of severe multi-access interference.

A Straight-line code, which consists of assignment, addition, and multiplication statements is an abstraction of a serial computer program to compute a function with n inputs. Given a serial straight-line code with N statements, the authors derive an algorithm that automatically evaluates not only the function but also its first-order derivatives with respect to the n inputs on a parallel computer. The basic idea of the algorithm is to marry automatic computation of derivatives with automatic parallelization of serial programs. The algorithm requires O(M{sub N} log of N) scalar operations, where O(M{sub N}) is the time complexity of a parallel multiplication of two dense N x N matrices and it represents a measure of the complexity of the straight-line code. Although it can be exponential in N in the worse case, it tends to be only polynomial in N for many important problems.

Accelerator mass spectrometry (AMS) quantifies attomole (10{sup -18}) amounts of {sup 14}C in milligram sized samples. This sensitivity is used to trace nutrients, toxins and therapeutics in humans and animals at less than {micro}g/kg doses containing 1-100 nCi of {sup 14}C. Widespread use of AMS in pharmaceutical development and biochemical science has been hampered by the size and expense of the typical spectrometer that has been developed for high precision radiocarbon dating. The precision of AMS can be relaxed for biochemical tracing, but sensitivity, accuracy and throughput are important properties that must be maintained in spectrometers designed for routine quantification. We are completing installation of a spectrometer that will maintain the high throughput of our primary spectrometer but which requires less than 20% of the floor space and of the cost. Sensitivity and throughput are kept high by using the LLNL intense cesium sputter ion source with solid graphitic samples. Resultant space-charge effects are minimized by careful modeling to find optimal ion transport in the spectrometer. A long charge-changing ''stripper gas'' volume removes molecular isobars at potentials of a few hundred kiloVolts, reducing the size of the accelerating component. Fast ion detectors count at high rates to keep a wide …

Welcome to a workshop on contamination Control techniques. This work shop is designed for about two hours. Attendee participation is encouraged during the workshop. We will address different topics within contamination control techniques; present processes, products and equipment used here at Hanford and then open the floor to you, the attendees for your input on the topics.

As radiation safety specialists, one of the things we are required to do is evaluate tools, equipment, materials and work practices and decide whether the use of these products or work practices will reduce radiation dose or risk to the environment. There is a tendency for many workers that work with radioactive material to accomplish radiological work the same way they have always done it rather than look for new technology or change their work practices. New technology is being developed all the time that can make radiological work easier and result in less radiation dose to the worker or reduce the possibility that contamination will be spread to the environment. As we discuss the various tools and techniques that reduce radiation dose, keep in mind that the radiological controls should be reasonable. We can not always get the dose to zero, so we must try to accomplish the work efficiently and cost-effectively. There are times we may have to accept there is only so much you can do. The goal is to do the smart things that protect the worker but do not hinder him while the task is being accomplished. In addition, we should not demand that large …

Compact stellarators have the potential to combine the best features of the stellarator and the advanced tokamak, offering steady state operation without current drive and potentially without disruptions at an aspect ratio similar to tokamaks. A quasi-axisymmetric stellarator is developed that is consistent with the boot-strap current and passively stable to the ballooning, kink, Mercier, vertical, and neoclassical tearing modes at b=4.1 % without need for conducting walls or external feedback. The configuration has good flux surfaces and fast ion confinement. Thermal transport analysis indicates that the confinement should be similar to tokamaks of the same size, allowing access to the b-limit with moderate power. Coils have been designed to reproduce the physics properties. Initial analysis indicates the coils have considerable flexibility to manipulate the configuration properties. Simulations of the current evolution indicate the kink-mode can remain stable during the approach to h igh-beta.

The Simulation Intranet/Product Database Operator (SI/PDO) project has developed a Web-based distributed object architecture for high performance scientific simulation. A Web-based Java interface guides designers through the design and analysis cycle via solid and analytical modeling, meshing, finite element simulation, and various forms of visualization. The SI/PDO architecture has evolved in steps towards satisfying Sandia's long-term goal of providing an end-to-end set of services for high fidelity full physics simulations in a high-performance, distributed, and distance computing environment. This paper describes the continuing evolution of the architecture to provide high-performance visualization services. Extensions to the SI/PDO architecture allow web access to visualization tools that run on MP systems. This architecture makes these tools more easily accessible by providing web-based interfaces and by shielding the user from the details of these computing environments. The design is a multi-tier architecture, where the Java-based GUI tier runs on a web browser and provides image display and control functions. The computation tier runs on MP machines. The middle tiers provide custom communication with MP machines, remote file selection, remote launching of services, load balancing, and machine selection. The architecture allows middleware of various types (CORBA, COM, RMI, sockets, etc.) to connect the tiers depending …

Some of the highlights of the 14th International Symposium on Spin Physics are presented with emphasis on recent and planned progress in experimental tools and tools and facilities.

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Argonne National Laboratory (ANL) has been creating a special-purpose software-engineering tool to support research and development of spectrum-output-type [chemical] sensors. The modular software system is called SAGE, the Sensor Algorithm Generation Environment and includes general-purpose signal conditioning algorithms (GP/SAGE) as well as intelligent classifiers, pattern recognizes, response accelerators, and sensitivity analyzers. GP/SAGE is an implementation of an approach for delivering a level of encapsulated intelligence to a wide range of sensors and instruments. It capitalizes on the genene classification and analysis needed to process most profile-type data. The GP/SAGE native data format is a generalized one-dimensional vector, signature, or spectrum. GP/SAGE modules form a computer-aided software engineering (CASE) workbench where users can experiment with various conditioning, filtering, and pattern recognition stages, then automatically generate final algorithm source code for data acquisition and analysis systems. SAGE was designed to free the [chemical] sensor developer from the signal processing allowing them to focus on understanding and improving the basic sensing mechanisms. The SAGE system's strength is its creative application of advanced neural computing techniques to response-vector and response-surface data, affording new insight and perspectives with regard to phenomena being studied for sensor development.

The recent progress in polarized ion source development is reviewed. In dc operation a 1.0 mA polarized H{sup -} ion current is now available from the Optically-Pumped Polarized Ion Source (OPPIS) . In pulsed operation a 10 mA polarized H{sup -} ion current was demonstrated at the TRIUMF pulsed OPPIS test bench and a 3.5 mA peak current was obtained from an Atomic Beam Source (ABS) at the INR Moscow test bench. The possibilities for future improvements with both techniques are discussed. A new OPPIS for RHIC spin physics is described. The OPPIS reliably delivered polarized beam for the polarized run at RHIC. The results obtained with a new pulsed ABS injector for the IUCF Cooler Ring are also discussed.

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A radio frequency (rf) system has been installed on the National Spherical Torus Experiment (NSTX) with the aim of heating the plasma and driving plasma current. The system consists of six rf transmitters, a twelve element antenna and associated transmission line components to distribute and couple the power from the transmitters to the antenna elements in a fashion to allow control of the antenna toroidal wavenumber spectrum. To date, power levels up to 3.85 MW have been applied to the NSTX plasmas. The frequency and spectrum of the rf waves has been selected to heat electrons via Landau damping and transit time magnetic pumping. The electron temperature has been observed to increase from 400 to 900 eV with little change in plasma density resulting in a plasma stored energy of 59 kJ and a toroidal beta, bT , =10% and bn = 2.7.

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