BLITZEN: A highly integrated massively parallel machine

The architecture and VLSI design of a new massively parallel processing array chip are described. The BLITZEN processing element array chip, which contains 1.1 million transistors, serves as the basis for a highly integrated, miniaturized, high-performance, massively parallel machine that is currently under development. Each processing element has 1K bits of static RAM and performs bit-serial processing with functional elements for arithmetic, logic, and shifting

When should you consider implanted nerve stimulators for lower back pain?

Patients can gain more pain relief from spinal cord stimulation (SCS) than from reoperation (strength of recommendation [SOR]: A, 2 randomized controlled trials [RCTs]). SCS can also treat chronic low back pain effectively (SOR: B, cohort studies). It's indicated when conservative measures have failed (SOR: C, expert opinion). The side effects and failure rates of SCS are well documented and should be considered before recommending the therapy to patients (SOR: A, systematic review of RCTs and cohort studies)

Nitrous Oxide Flux from Poultry-Manured Erosion Plots and Grass Filters after Simulated Rain

Adding carbon-rich materials to fields, like manure, may enhance denitrification. Grass filters, which are used to trap surface runoff from these fields, may also provide a carbon-rich environment that favors water infiltration and denitrification. Nitrous oxide (N2O) may be evolved these settings. It is a radiatively important trace gas and intermediate in the denitrification pathway and several other microbial processes. We measured N2O flux, after simulated rain, using a soil cover technique in poultry-manured plots and grass filters receiving their runoff. Intact soil cores were used to relate the N2O flux to the denitrification potential of the plots. Nitrous oxide fluxes were smaller in grass filters than in manured plots, even though more denitrifying bacteria were present. The average N2O flux in the three most dynamic erosion plots was 755 µg N2O-N m−2h−1, which was 39% of the maximal denitrification rate measured in acetylene-blocked, NO−3-amended soil cores. Nitrous oxide flux immediately after rainfall was greater than N2O flux measurements reported for similar agricultural settings

Filter Strip Length and Fecal Bacteria Trapping from Poultry Waste - An Update

Cheap, efficient, and environmentally sound waste disposal will be needed as Kentucky\u27s broiler industry expands. The filter strip length needed to protect water resources from contaminants in surface runoff is a pressing issue in waste management and water quality. In a previous Soil Science News and Views (Vol. 15, No. 8) we reported that grass filter strips as short as 15 feet can trap over 90% of the fecal bacteria eroding from land-applied and incorporated poultry waste during runoff following rainstorms. In this update, we provide some additional information and conclusions from that study on filter strip length, based on comparisons of filter strips receiving equal amounts of surface runoff

Nitrous Oxide Flux from Poultry-Manured Erosion Plots and Grass Filters after Simulated Rain

Adding carbon-rich materials to fields, like manure, may enhance denitrification. Grass filters, which are used to trap surface runoff from these fields, may also provide a carbon-rich environment that favors water infiltration and denitrification. Nitrous oxide (N2O) may be evolved these settings. It is a radiatively important trace gas and intermediate in the denitrification pathway and several other microbial processes. We measured N2O flux, after simulated rain, using a soil cover technique in poultry-manured plots and grass filters receiving their runoff. Intact soil cores were used to relate the N2O flux to the denitrification potential of the plots. Nitrous oxide fluxes were smaller in grass filters than in manured plots, even though more denitrifying bacteria were present. The average N2O flux in the three most dynamic erosion plots was 755 µg N2O-N m−2h−1, which was 39% of the maximal denitrification rate measured in acetylene-blocked, NO−3-amended soil cores. Nitrous oxide flux immediately after rainfall was greater than N2O flux measurements reported for similar agricultural settings

Trapping Fecal Bacteria and Sediment in Surface Runoff From Cropland Treated With Poultry Litter

Between 1991 and 1994 the broiler population exploded in Kentucky as the poultry industry began to expand. The Kentucky Department of Agriculture predicts that within four years annual broiler production could exceed 275 million birds. This may be good for Kentucky\u27s economy but it carries some important environmental consequences. If expansion continues as anticipated, the estimated waste production from broilers for processing could reach 300,000 tons per year (assuming each broiler house produces 150,000 birds per year and the yearly manure and litter production per house is approximately 160 tons)

Bimodality In Interim Reports: An Analysts' View

Cumulative abnormal residuals (cars) show how markets adjust to published information. Theoretically, cars are assumed to display unit normal behavior.  Despite its merits, car has proved to be a somewhat imprecise measure of market response to published information.  In practice, cars exhibit considerable deviation from theoretical unit normal behavior. Three disparities between theory and practice can be pinpointed.  These are car: (1) location, (2) shape, and (3) stability.  In our previous work we have demonstrated that cars are often bimodally distributed.  This finding shows one reason why it takes semistrong efficient markets some time to digest new information. Cars, for the time period during which markets analyze the new value determining data, are usually bimodally distributed. One mode of the distribution represents the impact of good news. The other peak is caused by bad news.  The valley, between the two peaks, indicates the influence of neutral news.  This paper analyzes the interim reports, which constitute the data for our previous related studies. This research identifies the type of new information that creates bimodal cars

Interaction of reed and acoustic resonator in clarinetlike systems

Sound emergence in clarinetlike instruments is investigated in terms of instability of the static regime. Various models of reed-bore coupling are considered, from the pioneering work of Wilson and Beavers ["Operating modes of the clarinet", J. Acoust. Soc. Am. 56, 653--658 (1974)] to more recent modeling including viscothermal bore losses and vena contracta at the reed inlet. The pressure threshold above which these models may oscillate as well as the frequency of oscillation at threshold are calculated. In addition to Wilson and Beavers' previous conclusions concerning the role of the reed damping in the selection of the register the instrument will play on, the influence of the reed motion induced flow is also emphasized, particularly its effect on playing frequencies, contributing to reduce discrepancies between Wilson and Beavers' experimental results and theory, despite discrepancies still remain concerning the pressure threshold. Finally, analytical approximations of the oscillating solution based on Fourier series expansion are obtained in the vicinity of the threshold of oscillation. This allows to emphasize the conditions which determine the nature of the bifurcation (direct or inverse) through which the note may emerge, with therefore important consequences on the musical playing performances