Article analyzing transposon insertion mutants resulting in independent loss of function of five enzymes of the monolignol pathway, as well as one double mutant, in the model legume Medicago truncatula, to address whether a common mechanism linking lignin modification with perturbations in plant growth and development exists.

Article presents research using hospital-level data from the US to determine whether private patient rooms (PPRs) are associated with fewer in hospital-acquired methicillin-resistant Staphylococcus aureus (HA-MRSA) infections.

Article presenting research where an electropolymerizable zinc porphyrin carrying eight entities of peripheral bithiophene, 4 was newly designed and synthesized.

Article expressing two closely related plant FAD3 genes in yeast cells and found that their enzymes produced significantly different amounts of omega-3 fatty acids and that these differences correlated to differences in rates of protein turnover. The findings indicate that Fad3 protein abundance is regulated by a combination of cis-acting degradation signals and the ubiquitin-proteasome pathway and that modulation of Fad3 protein amounts in response to temperature may represent one mechanism of homeoviscous adaptation in plants.

Free space optical communications (FSO) are beginning to provide attractive alternatives to fiber-based solutions in many situations. Currently, a handful of companies provide fiberless alternatives specifically aimed at corporate intranet and sporting event video applications. These solutions are geared toward solving the ''last mile'' connectivity issues. There exists a potential need to extend this pathlength to distances much greater than a 1 km, particularly for government and military applications. For cases of long distance optical propagation, atmospheric turbulence will ultimately limit the maximum achievable data rate. In this paper, we propose a method to improve signal quality through the use of adaptive optics. In particular, we show work in progress toward a high-speed, small footprint Adaptive Optics system for horizontal and slant path laser communications. Such a system relies heavily on recent progress in Micro-Electro-Mechanical Systems (MEMS) deformable mirrors, as well as improved communication and computational components.

In order to develop a phenomenological approach to transport in 3D heterogeneous media, we have performed direct numerical simulation studies. Using an algorithm based on the lattice random walk to generate random media, we have performed radiographic shots of the sample and digitized both the chord length and optical depth distributions. The optical depth distribution is then used to compute an effective mean free path. As theory predicts, the atomically averaged mean free path is always a minimum value. We have also demonstrated a dependency of mean free path on the distribution of random material.

Experimental studies of capillary-dominated displacements in variable-aperture fractures have demonstrated the occurrence of a satiated state at the end of invasion, where significant entrapment of the displaced phase occurs. The structure of this entrapped phase controls the behavior of flow and transport processes in the flowing phase. Recent studies have shown that the areal saturation of the flowing phase at satiation (S{sub f}) is largely controlled by a single parameter C/{delta}, where C, the Curvature number, weighs the mean in-plane interfacial curvature relative to the mean out-of-plane interfacial curvature, and {delta}, the coefficient of variation of the aperture field, represents the strength of interface roughening induced by aperture variations. Here we consider the satiated relative permeability (k{sub rs}) to the flowing phase, which is defined as the relative permeability at satiation, when the defending phase is fully entrapped. The satiated relative permeability is shown to be a well-defined function of S{sub f} over a wide range of C/{delta}, ranging from capillary fingering with significant entrapment (C/{delta} {yields} 0) to smooth invasion with very little entrapment (C/{delta} > 1). We propose a relationship, based on effective medium theory, for the satiated relative permeability as a function of S{sub f}. The predicted …

The authors describe ROSE, a C++ infrastructure for source-to-source translation, that provides an interface for programmers to easily write their own translators for optimizing user-defined high-level abstractions. Utilizing the semantics of these high-level abstractions, they demonstrate the automatic parallelization of loops that iterate over user-defined containers that have interfaces similar to the lists, vectors and sets in the Standard Template Library (STL). The parallelization is realized in two phases. First, they insert OpenMP directives into a serial program, driven by the recognition of the high-level abstractions, containers, that are thread-safe. Then, they translate the OpenMP directives into library routines that explicitly create and manage parallelism. By providing an interface for the programmer to classify the semantics of their abstractions, they are able to automatically parallelize operations on containers, such as linked-lists, without resorting to complex loop dependence analysis techniques. The approach is consistent with general goals within telescoping languages.

The town of Mailuu-Suu in Kyrgyzstan inherited 23 distinct tailings deposits from Soviet-Era uranium mining operations. Mailuu-Suu is located in the narrow landslide-prone valley of the Mailuu-Suu River about 25 km from the Uzbekistan border. Large-scale release of the radioactive tailings, as a result of landslides, could lead to irreversible contamination of the river and downstream areas. The Mailuu-Suu River is a tributary to the Syr-Darya River, the Fergana valley's main source of irrigation water. The Fergana Valley is a key agricultural region and major population center that spans Kyrgyzstan, Tajikistan, and Uzbekistan. The trans-boundary nature of the Mailuu-Suu tailings issue presents an opportunity for collaboration among these Central Asian states. A cooperative approach to addressing environmental issues such as Mailuu-Suu may contribute to the region's stability by facilitating peaceful associations. Experience from remediation of sites in the US under the Uranium Mill Tailings Remediation Action Project (UMTRA) will be useful in progressing toward remediation at Mailuu-Suu.

Our current understanding of ultraluminous infrared galaxies suggest that they are recent galaxy mergers in which much of the gas in the former spiral disks, particularly that located at distances less than 5 kpc from each of the pre-merger nuclei, has fallen into a common center, triggering a huge starburst phenomenon. This large nuclear concentration of molecular gas has been detected by many groups, and estimates of molecular mass and density have been made. Not surprisingly, these estimates were found to be orders of magnitude larger than the corresponding values found in our Galaxy. In this paper, a self-consistent model of the high energy emission of the super-starburst galaxy Arp 220 is presented. The model also provides an estimate of the radio emission from each of the components of the central region of the galaxy (western and eastern extreme starbursts, and molecular disk). The predicted radio spectrum is found as a result of the synchrotron and free-free emission, and absorption, of the primary and secondary steady population of electrons and positrons. The latter is output of charged pion decay and knock-on leptonic production, subject to a full set of losses in the interstellar medium. The resulting radio spectrum is in …

An O-CDMA TD based on 2-D (wavelength/time) codes is described, with bit-error-rate (BER) and eye-diagram measurements given for eight users. Simulations indicate that the TD can support 32 asynchronous users.

By accurately profiling the users via their unique attributes, it is possible to view the intrusion detection problem as a classification of authorized users and intruders. This paper demonstrates that artificial neural network (ANN) techniques can be used to solve this classification problem. Furthermore, the paper compares the performance of three neural networks methods in classifying authorized users and intruders using synthetically generated data. The three methods are the gradient descent back propagation (BP) with momentum, the conjugate gradient BP, and the quasi-Newton BP.

Our identification research for the past several years has focused on the problem of correctly discriminating small-magnitude explosions from a background of earthquakes, mining tremors, and other events. Small magnitudes lead to an emphasis on regional waveforms. It has been shown that at each test site where earthquake and explosions are in close proximity and recorded at the same station, clear differences in the regional body waves such as the relative high frequency amplitudes of P and S waves can be used to discriminate between event types. However path and source effects can also induce such differences, therefore these must be quantified and accounted for. We have been using a specific technique called Magnitude and Distance Amplitude Correction (MDAC), with some success to account for some of these effects.

The National Nuclear Security Administration (NNSA) Ground-Based Nuclear Explosion Monitoring Research and Engineering (GNEM R&E) Program has made significant progress enhancing the process of deriving seismic calibrations and performing scientific integration with automation tools. We present an overview of our software automation efforts and framework to address the problematic issues of very large datasets and varied formats utilized during seismic calibration research. The software and scientific automation initiatives directly support the rapid collection of raw and contextual seismic data used in research, provide efficient interfaces for researchers to measure/analyze data, and provide a framework for research dataset integration. The automation also improves the researcher's ability to assemble quality controlled research products for delivery into the NNSA Knowledge Base (KB). The software and scientific automation tasks provide the robust foundation upon which synergistic and efficient development of, GNEM R&E Program, seismic calibration research may be built. The task of constructing many seismic calibration products is labor intensive and complex, hence expensive. However, aspects of calibration product construction are susceptible to automation and future economies. We are applying software and scientific automation to problems within two distinct phases or 'tiers' of the seismic calibration process. The first tier involves initial collection of …

Precision position knowledge (< 25 microns RMS) of the GEM Detector muon system at the Superconducting Super Collider Laboratory (SSCL) is an important physics requirement necessary to minimize sagitta error in detecting and tracking high energy muons that are deflected by the magnetic field within the GEM Detector. To validate the concept of the sagitta correction function determined by projective alignment of the muon detectors (Cathode Strip Chambers or CSCs), the basis of the proposed GEM alignment scheme, a facility, called the ``Alignment Test Stand`` (ATS), is being constructed. This system simulates the environment that the CSCs and chamber alignment systems are expected to experience in the GEM Detector, albeit without the 0.8 T magnetic field and radiation environment. The ATS experimental program will allow systematic study and characterization of the projective alignment approach, as well as general mechanical engineering of muon chamber mounting concepts, positioning systems and study of the mechanical behavior of the proposed 6 layer CSCs. The ATS will consist of a stable local coordinate system in which mock-ups of muon chambers (i.e., non-working mechanical analogs, representing the three superlayers of a selected barrel and endcap alignment tower) are implemented, together with a sufficient number of alignment …

The superconducting magnets in Fusion Reactors are subjected to pulsed, nuclear, and resistive heating. The thermo-hydraulic response of the helium forced-flow cooled conductors to the various heat sources is critical to magnet design and performance. Recently developed computer codes allow accurate modeling of conductor response and have been used as an aid to design of the toroidal field (TF) magnets for the Tokamak Physics experiment (TPX). We present results of design studies that determine the trade-off between double- and single-pancake helium flow configurations, the minimum-temperature margin, and the stability against rapid heat input. The results guide the choice and design of the liquid helium refrigerator.

Airborne temperature surveys were used to depict the small surface temperature differences related to heat flow anomalies. Zones with conductive heat flow differences of 45 +- 16 ..mu..cal/cm/sup 2/(s) had predawn surface temperature differences of 1.4 +- 0.3/sup 0/C. Airborne temperature surveys were coordinated with field temperature surveys at Long Valley, California, the site of a known geothermal resource area. The airborne temperature surveys recorded redundant, predawn temperatures at two wavelengths and at two elevations. Overall temperature corrections were determined by calibrating dry soil surface temperatures with thermistor probes. The probes measured air and soil temperatures within 2 cm of the surface, every twenty minutes, during the survey overflights.

For the United States Nuclear Regulatory Commission, a procedure was developed and tested for the evaluation of Material Control and Accounting (MC and A) Systems at nuclear fuel facilities. This procedure, called the Structured Assessment Approach, SAA, subjects the MC and A system at a facility to a series of increasingly sophisticated adversaries and strategies. A fully integrated version of the computer codes which assist the analyst in this assessment will become available in October 1979. The concepts of the SAA and the results of the assessment of a hypothetical but typical facility are presented.

An overview of inertial confinement fusion pellet physics is given. A discussion is presented of current estimated ICF driver requirements and a couple of pellet examples. The physics of driver/plasma coupling for two drivers which are being considered, namely a laser driver and a heavy ion accelerator driver, is described. Progress towards inertial confinement fusion that has been made using laser drivers in target experiments to date is discussed.

The technology for producing high fields in large superconducting magnets has increased greatly in recent years, but must increase still more in the future. In this paper, we examine the present state of the art vis-a-vis the needs of a next-generation fusion machine and outline a program to provide for those needs. We also highlight recent developments that suggest the program goals are within reach.

We discuss the results of SEM and TEM measurements with the BPRML test samples fabricated from a BPRML (WSi2/Si with fundamental layer thickness of 3 nm) with a Dual Beam FIB (focused ion beam)/SEM technique. In particular, we demonstrate that significant information about the metrological reliability of the TEM measurements can be extracted even when the fundamental frequency of the BPRML sample is smaller than the Nyquist frequency of the measurements. The measurements demonstrate a number of problems related to the interpretation of the SEM and TEM data. Note that similar BPRML test samples can be used to characterize x-ray microscopes. Corresponding work with x-ray microscopes is in progress.

MRI is a powerful technique for clinical diagnosis and materials characterization. Images are acquired in a homogeneous static magnetic field much higher than the fields generated across the field of view by the spatially encoding field gradients. Without such a high field, the concomitant components of the field gradient dictated by Maxwell's equations lead to severe distortions that make imaging impossible with conventional MRI encoding. In this paper, we present a distortion-free image of a phantom acquired with a fundamentally different methodology in which the applied static field approaches zero. Our technique involves encoding with pulses of uniform and gradient field, and acquiring the magnetic field signals with a SQUID. The method can be extended to weak ambient fields, potentially enabling imaging in the Earth's field without cancellation coils or shielding. Other potential applications include quantum information processing and fundamental studies of long-range ferromagnetic interactions.

Continuous, large-scale efforts to improve and develop third- and forth-generation synchrotron radiation light sources for unprecedented high-brightness, low emittance, and coherent x-ray beams demand diffracting and reflecting x-ray optics suitable for micro- and nano-focusing, brightness preservation, and super high resolution. One of the major impediments for development of x-ray optics with the required beamline performance comes from the inadequate present level of optical and at-wavelength metrology and insufficient integration of the metrology into the fabrication process and into beamlines. Based on our experience at the ALS Optical Metrology Laboratory, we review the experimental methods and techniques that allow us to mitigate significant optical metrology problems related to random, systematic, and drift errors with super-high-quality x-ray optics. Measurement errors below 0.2 mu rad have become routine. We present recent results from the ALS of temperature stabilized nano-focusing optics and dedicated at-wavelength metrology. The international effort to develop a next generation Optical Slope Measuring System (OSMS) to address these problems is also discussed. Finally, we analyze the remaining obstacles to further improvement of beamline x-ray optics and dedicated metrology, and highlight the ways we see to overcome the problems.

We overview the results of a broad US collaboration, including all DOE synchrotron labs (ALS, APS, BNL, NSLS-II, LLNL, LCLS), major industrial vendors of x-ray optics (InSync, Inc., SSG Precision Optronics-Tinsley, Inc., Optimax Systems, Inc.), and with active participation of HBZ-BESSY-II optics group, on development of a new generation slope measuring profiler -- the optical slope measuring system (OSMS). The desired surface slope measurement accuracy of the instrument is&lt;50 nrad (absolute) that is adequate to the current and foreseeable future needs for metrology of x-ray optics for the next generation of light sources.