Cortical Sensorimotor Interactions During the Expectancy of a Go/No-Go Task: Effects of Painful Stimuli.

The intent of this electroencephalography study was to investigate the competition between cortical nociceptive and cognitive-motor processes preceding sensorimotor interactions. Sensorimotor expectancy processes to painful stimulation and motor go/no-go demands were indexed over primary sensorimotor and midline cortical areas by contingent negative variation (CNV). Before the sensorimotor interaction, CNV was observed over midline posterior and bilateral central areas. Early expectancy of painful stimulation and the go/no-go task induced an evident midline posterior CNV. During the late expectancy period. CNV extended to the right central area contralateral to the stimulation. These findings suggest a sequential activation of midline posterior and primary sensorimotor areas contralateral to the painful stimulation as a reflection of the enhanced nociceptive processes preceding painful sensorimotor interactions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Deactivation and regeneration of spent three-way automotive exhaust gas catalysts (TWC)

Topics in Catalysis - The effect of oxidation, oxy-chlorination and reduction treatments at elevated temperatures on the dispersion of palladium (Pd) and rhodium (Rh) for commercially aged...     

Preliminary study of spent UO2 fuel corrosion in the presence of bentonite

The corrosion of spent UO₂ fuel in the presence of a dilute suspension (1.5%) of bentonite in synthetic groundwater has been studied. No significant changes in the uranium concentrations no indications of increased corrosion due to changes in solution chemistry, or due to sorption was found when bentonite was introduced to the system. The measured uranium concentrations were (3 ± 2) × 10⁻⁶M in the presence as well as in the absence of bentonite. The concentrations of plutonium and cationic fission products in the aqueous phase were lowered considerably, by up to two orders of magnitude in the case of plutonium due to sorption onto the bentonite.     

A Low-Power Heterogeneous Multiprocessor Architecture for Audio Signal Processing

This paper describes a low-power programmable DSP architecture that targets audio signal processing. The architecture can be characterized as a heterogeneous multiprocessor consisting of small instruction set processors called mini-cores as well as standard DSP and CPU cores that communicate using message passing. The mini-cores are tailored for different classes of filtering algorithms (FIR, IIR, N-LMS etc.), and in a typical system the communication among processors occur at the sampling rate only.The mini-cores are intended as soft-macros to be used in the implementation of system-on-chip solutions using a synthesis-based design flow targeting a standard-cell implementation. They are parameterized in word-size, memory-size, etc. and can be instantiated according to the needs of the application. To give an impression of the size of a mini-core we mention that one of the FIR mini-cores in a prototype design has 16 instructions, a 32-word × 16-bit program memory, a 64-word × 16-bit data memory and a 25-word × 16-bit coefficient memory.Results obtained from the design of a prototype chip containing mini-cores for a hearing aid application, demonstrate a power consumption that is only 1.5–1.6 times larger than a hardwired ASIC and more than 6–21 times lower than current state of the art low-power DSP processors. This is due to: (1) the small size of the processors and (2) a smaller instruction count for a given task.     

A Brief History of Catalysis

Historical studies are usually divided into segments of time that were marked by intellectual progress or specific achievements. Some periods are clearly identified by great events or an individual accomplishment that revolutionizes the entire concept. However, in most cases the advancement from one period to another is not marked by distinct accomplishments, but rather the result of a series of advances. This paper follows this conventional style and we have divided our subject of catalysis into five distinct periods.     

Prüffeldorientierte Zuordnung von Prüfern für die operative Personaleinsatzplanung in Wirtschaftsprüfungsgesellschaften

Zusammenfassung Basierend auf den Ergebnissen einer empirischen Untersuchung wurde ein hierarchischer Ansatz zur Personaleinsatzplanung in Wirtschaftsprüfungsgesellschaften entwickelt, der die Teilprobleme der taktischen, der taktisch-operativen und der operativen Planung umfaßt. Der vorliegende Beitrag setzt sich mit der operativen Planung auseinander. Das Problem wird zunächst als binäres Optimierungsproblem formuliert. Anschließend wird ein speziell an die Problemstruktur angepaßtes heuristisches Verfahrensschema vorgestellt, das unter Verwendung von Prioritätswerten randomisierte Auswahlentscheidungen trifft. Die Eignung des Verfahrensschemas wird in einer umfangreichen experimentellen Untersuchung nachgewiesen.     

Das Blockdiagramm und die “Systemingenieure”. Eine Visualisierungspraxis zwischen Wissenschaft und Öffentlichkeit in der US-amerikanischen Nachkriegszeit

With the rise of the system approach in World War II, US-engineers developed new design techniques to manage complex socio-technical systems, especially military ones. One of these new methods was the use of block diagrams which should guarantee a rational design process without eliminating the traditional visual habitus of the engineering community. This text argues that the block diagram, as a new visual design method, was embedded in the process of establishing a new engineering science, called system engineering. Furthermore, the block diagram symbolized the changed role of technical experts in the Cold War era, who were regarded as competent problem solvers and as a community that could protect the national security by developing complex military technology. Two images, that were parts of advertisments in theScientific American, shall be used to demonstrate the block diagram’s function in the public sphere as a symbol that represents a new technocratic interpretation of modernity.      

Apparent lack of effect of obesity on the soluble phosphatidic acid phosphatase activity in human adipose tissue

In view of previous reports that the activity of the Mg⁺⁺-dependent phosphatidic acid phosphatase in adipose tissues of rat and mouse is elevated in obesity, we attempted to assay this activity in biopsies of human omental adipose tissue obtained from normal-weight and morbidly obese subjects in connection with operations. The major portion of the phosphatidic acid phosphatase activity was found in the cytosol, and the small amount found in the microsomal fraction was too low for accurate measurement. It was not possible to assay the activity in the crude cytosol. After precipitation with ammonium sulfate, however, the enzyme activity was linear with both the incubation time and the concentration of enzyme. It was not possible to obtain substrate saturation of the enzyme under the conditions employed. When assayed in the presence of a high concentration of substrate (0.6 mmol/l) the activity obtained in normalweight pateints, 7.8±2.4 nmol/mg protein/min (n=10), was not significantly different from that in morbidly obese patients, 5.6±0.8 nmol/mg protein/min (n=10). There was no relation between the size of adipose cells and phosphatidic acid phosphatase activity. Furthermore, there was no apparent relation between phosphatidic acid phosphatase activity in omental adipose tissue and that in the liver The findings suggest that the increased biosynthesis of triglycerides in human obesity is not associated with an increased capacity of the soluble phosphatidic acid phosphatase in adipose tissue.     

On the relationship between lake trophic level and lake sediments

The purpose of this work has been to study the relationship between lake type, as expressed by various trophic characteristics, and sediment type, as expressed by determinations of simple chemical data on nitrogen, phosphorus, carbon and loss on ignition. The study is based on two sets of data. The first one emanates from 71 lakes for which information is available from published sources on trophic level and N-content and organic content (loss on ignition) from surficial sediments. More detailed information has been obtained from 12 Swedish lakes/basins on the following water indicators of trophic level: transparency, chlorophyll-a, total-N, total-P, organic-N, inorganic-N. The sediment data from these 12 lakes include: mean values and characteristic values for organic content (loss on ignition, IG) C-, N- and P-contents from surficial sediments. A BPN-value (bioproduction number) is defined by the slope coefficient of the regression line between N-content and IG-content of surficial sediments (0–1 cm). It has been shown that the BPN-value provides most accurate information about lake trophic level on the scale from oligotrophy to eutrophy, provided that more than 50% of the lake area has lower loss on ignition than 20% (per dry substance). The BPN-value cannot be used as an indicator of trophic level if the IG-content is predominantly higher than 30% in a lake. In the latter case the ratio IG/N can be used as a means to differentiate lake humic level. The BPN-value, which is determined from sediment samples providing an even spread throughout the lake surface, yields lake typical information, whereas C/N ratios yield site specific information. A key diagrammatic interpretation between lake trophic type and lake sediments has been presented.