Systolic opportunities for multidimensional data streams

Portable image processing applications require an efficient, scalable platform with localized computing regions. This paper presents a new class of area I/O systolic architecture to exploit the physical data locality of planar data streams by processing data where it falls. A synthesis technique using dependence graphs, data partitioning, and computation mapping is developed to handle planar data streams and to systematically design arrays with area I/O. Simulation results show that the use of area I/O provides a 16 times speedup over systems with perimeter I/O. Performance comparisons for a set of signal processing algorithms show that systolic arrays that consider planar data streams in the design process are up to three times faster than traditional arrays     

Focal-plane processing architectures for real-time hyperspectral image processing

Real-time image processing requires high computational and I/O throughputs obtained by use of optoelectronic system solutions. A novel architecture that uses focal-plane optoelectronic-area I/O with a fine-grain, low-memory, single-instruction-multiple-data (SIMD) processor array is presented as an efficient computational solution for real-time hyperspectral image processing. The architecture is evaluated by use of realistic workloads to determine data throughputs, processing demands, and storage requirements. We show that traditional store-and-process system performance is inadequate for this application domain, whereas the focal-plane SIMD architecture is capable of supporting real-time performances with sustained operation throughputs of 500-1500 gigaoperations/s. The focal-plane architecture exploits the direct coupling between sensor and parallel-processor arrays to alleviate data-bandwidth requirements, allowing computation to be performed in a stream-parallel computation model, while data arrive from the sensors.     

Reversal by desferrioxamine of tau protein aggregates following two days of treatment in aluminum-induced neurofibrillary degeneration in rabbit: implications for clinical trials in Alzheimer''s disease

Concern about possible transmission of bloodborne pathogens during medical procedures is growing among patients and healthcare workers alike. This fear has primarily been focused on nosocomial transmission of human immunodeficiency virus (HIV), but other bloodborne infectious agents may also be transmitted during procedures. Chief among these are the hepatitis viruses, particularly hepatitis B virus (HBV) and hepatitis C virus (HCV), both of which are significantly more widespread than HIV. Although radiology is not traditionally thought of as a field with significant risk for exposure to or transmission of pathogens, the expanding role of interventional procedures in recent years belies that perception. The potential for exposure to blood or other possibly infectious material exists in virtually any invasive radiological procedure, from arteriography to image-guided biopsy. Fortunately, the risk of such exposure is low, and the risk of actual transmission of a bloodborne pathogen, whether from patient to healthcare worker or vice versa, is even lower. Nevertheless, it is important for all radiologists who perform invasive procedures to be aware of these risks and to observe pertinent safety and infection control recommendations. This article will review these topics.     

The Data Vortex, an All Optical Path Multicomputer Interconnection Network

All optical path interconnection networks employing dense wavelength division multiplexing can provide vast improvements in supercomputer performance. However, the lack of efficient optical buffering requires investigation of new topologies and routing techniques. This paper introduces and evaluates the data vortex optical switching architecture which uses cylindrical routing paths as a packet buffering alternative. In addition, the impact of the number of angles on the overall network performance is studied through simulation. Using optimal topology configurations, the data vortex is compared to two existing switching architectures-butterfly and omega networks. The three networks are compared in terms of throughput, accepted traffic ratio, and average packet latency. The data vortex is shown to exhibit comparable latency and a higher acceptance rate (2times at 50 percent load) than the butterfly and omega topologies     

Conditions for copackaging rous sarcoma virus and murine leukemia virus Gag proteins during retroviral budding

Rous sarcoma virus (RSV) and murine leukemia virus (MLV) are examples of distantly related retroviruses that normally do not encounter one another in nature. Their Gag proteins direct particle assembly at the plasma membrane but possess very little sequence similarity. As expected, coexpression of these two Gag proteins did not result in particles that contain both. However, when the N-terminal membrane-binding domain of each molecule was replaced with that of the Src oncoprotein, which is also targeted to the cytoplasmic face of the plasma membrane, efficient copackaging was observed in genetic complementation and coimmunoprecipitation assays. We hypothesize that the RSV and MLV Gag proteins normally use distinct locations on the plasma membrane for particle assembly but otherwise have assembly domains that are sufficiently similar in function (but not sequence) to allow heterologous interactions when these proteins are redirected to a common membrane location.     

Ceramic Engine Valves

Current trends in spark ignition engines are toward multivalve engines capable of operating at relatively high speeds to maximize performance and fuel economy at acceptable emissions levels. Structural ceramics, with their low density and good high-temperature properties, appear to offer potential as an alternative valve material to the steels, superalloys, and titanium alloys currently in use. Progress to date on materials development, component design, component performance, and engine testing indicates that silicon nitride valves will operate satisfactorily.     

The temperature ranges for maximum effectiveness of grain growth inhibitors in WC–Co alloys

In order to more effectively control the WC grain growth during liquid phase sintering of submicron WC–Co alloys, the temperature ranges where common grain growth inhibitors are most active have been determined. In the study, small additions (0.5% by weight) of TiC, TaC, NbC, VC, and Cr₃C₂ were added to WC–6Co and WC–10Co alloys. In some cases, a small amount of coarse WC powder was added to simulate the effect of discontinuous grain growth. The powder compacts were vacuum sintered at temperatures ranging from 1300 to 1575 °C. The magnetic coercivity and microstructure results indicated that VC is equally effective in limiting continuous grain growth for all temperatures within the temperature range while the other inhibitors become more effective with temperature. VC was also found to be the most effective inhibitor of discontinuous grain growth. The results of the investigation are expressed in terms of the effectiveness of grain growth inhibition as determined by microstructural analysis, magnetic coercivity and hardness.     

Observed and perceived parental overprotection in relation to psychosocial adjustment in preadolescents with a physical disability: The mediational role of behavioral autonomy.

The purpose of this study was to test a mediational model of associations between parental overprotectiveness (OP), behavioral autonomy, and psychosocial adjustment in 68 families with 8- and 9-year-old preadolescents with spina bifida and a demographically matched sample of 68 families with able-bodied children. Measures included questionnaire and observational assessments of parental OP; parent and child reports of behavioral autonomy; and parent, child, and teacher reports of preadolescent adjustment. On the basis of both questionnaire and observational measures of OP, mothers and fathers of children with spina bifida were significantly more overprotective than their counterparts in the able-bodied sample, although this group difference was partially mediated by children's cognitive ability. Both questionnaire and observational measures of parental OP were associated with lower levels of preadolescent decision-making autonomy as well as with parents being less willing to grant autonomy to their offspring in the future. For the questionnaire measure of OP, and only for the spina bifida sample, the mediational model was supported such that parental OP was associated with less behavioral autonomy, which was, in turn, associated with more externalizing problems. (PsycINFO Database Record (c) 2010 APA, all rights reserved)