Semantic processing of non-attended visual information.

In 2 experiments, with 28 university students, reaction time (RT) to name 1 of 2 rows of letter material was measured. The reported row was always a word. In Exp I, the nonreported row contained either a word semantically related to the reported word, a nonassociated word, or a nonword. Nonwords were not used in Exp II. Attentional selectivity was varied by presenting a report cue either 250 msec prior to display onset or 250 msec after display onset. RT was faster when the report cue preceded the display, indicating that this cue induced selective attention. In both the selective and nonselective conditions, RT to name the target word was faster when the nonreported row contained a word associated with the target than when it contained a nonassociated word. However, this facilitation of RT produced by associated nonreported words was greater under the nonselective condition. While semantic information was extracted from both nonattended and attended visual material a larger semantic interaction occurred when attention was directed to both rows of a visual display. Results also indicate that the presence of nonwords influenced the strategy used to analyze a visual display. (French summary) (19 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A digital prescription for X-ray overload

The potential of picture-archiving and communication systems (PACs), a technology for the transmission and storage of diagnostic images, is examined. PACs, which accept pictures or images, with associated test, in digital form and then distributes them over a network, offer a means of dealing with the explosive growth of information generated by radiology and other imaging modalities. The technological problems that must be solved before PACS can achieve widespread use are explored. These occur in the areas of storing, transmitting, and displaying the images. Standard issues and radiologists' resistance to the digital hospital, which may be the greatest obstacle to implementing PACS, are discussed     

Effect of Pre-coated Vs. Added Coupling Agents on the Vulcanization of Silica-filled Polyisoprene

Solid-state ¹³C NMR was utilized in analysis of the crosslink structure in silica-filled polyisoprene. Samples containing either a pre-coated coupling agent, a coupling agent added in the mixing process, or polyethylene glycol (PEG) were vulcanized and the type and density of crosslinking determined. The precoated coupling agent sample gave lower %swelling, lower extraction amounts, and a lower T₂ relaxation than the mixed coupling agent, indicating increased crosslinking or increased filler -rubber interaction. The precoated also showed less cis -trans isomerization than the mixed, which may be due to its more uniform coating effect on the silica. The PEG sample yielded a ¹³C spectrum similar to an unfilled sample indicating decreased silica adsorption of vulcanization agents. Neither coupling agent significantly decreased the total sulfurization nor the percent monosulfidic crosslinks from that of a silica-filled sample without coupling agent.     

Inactivation of hepatitis A virus by high-pressure processing: the role of temperature and pressure oscillation

Inactivation of hepatitis A virus (HAV) in Dulbecco's modified Eagle medium with 10% fetal bovine serum was studied at pressures of 300, 350, and 400 MPa and initial sample temperatures of -10, 0, 5, 10, 20, 30, 40, and 50 degrees C. Sample temperature during pressure application strongly influenced the efficiency of HAV inactivation. Elevated temperature (> 30 degrees C) enhanced pressure inactivation of HAV, while lower temperatures resulted in less inactivation. For example, 1-min treatments of 400 MPa at -10, 20, and 50 degrees C reduced titers of HAV by 1.0, 2.5, and 4.7 log PFU/ml, respectively. Pressure inactivation curves of HAV were obtained at 400 MPa and three temperatures (-10, 20, and 50 degrees C). With increasing treatment time, all three temperatures showed a rapid initial drop in virus titer with a diminishing inactivation rate (or tailing effect). Analysis of inactivation data indicated that the Weibull model more adequately fitted the inactivation curves than the linear model. Oscillatory high-pressure processing for 2, 4, 6, and 8 cycles at 400 MPa and temperatures of 20 and 50 degrees C did not considerably enhance pressure inactivation of HAV as compared with continuous high-pressure application. These results indicate that HAV exhibits, unlike other viruses examined to date, a reduced sensitivity to high pressure observed at cooler treatment temperatures. This work suggested that slightly elevated temperatures are advantageous for pressure inactivation of HAV within foods.     

Polypyrrole/MWNT nanocomposites synthesized through interfacial polymerization

Polypyrrole/carbon nanotubes (CNTs) composites were synthesized by dispersion of organically modified multiwall carbon nanotubes during an interfacial polymerization of pyrrole. During the polymerization, the carbon nanotubes are entrapped by the polymer chains and the nanocomposite is formed in the interphase between two immiscible solvents. The method favours a better dispersion of the nanotubes in the polypyrrole offering enhanced electrical properties. The characterisation of the composite material has been established by XRD, TGA analysis and electron microscopy techniques.     

Inactivation of hepatitis A virus and a calicivirus by high hydrostatic pressure

Potential application of high hydrostatic pressure processing (HPP) as a method for virus inactivation was evaluated. A 7-log10 PFU/ml hepatitis A virus (HAV) stock, in tissue culture medium, was reduced to nondetectable levels after exposure to more than 450 MPa of pressure for 5 min. Titers of HAV were reduced in a time- and pressure-dependent manner between 300 and 450 MPa. In contrast, poliovirus titer was unaffected by a 5-min treatment at 600 MPa. Dilution of HAV in seawater increased the pressure resistance of HAV, suggesting a protective effect of salts on virus inactivation. RNase protection experiments indicated that viral capsids may remain intact during pressure treatment, suggesting that inactivation was due to subtle alterations of viral capsid proteins. A 7-log10 tissue culture infectious dose for 50% of the cultures per ml of feline calicivirus, a Norwalk virus surrogate, was completely inactivated after 5-min treatments with 275 MPa or more. These data show that HAV and a Norwalk virus surrogate can be inactivated by HPP and suggest that HPP may be capable of rendering potentially contaminated raw shellfish free of infectious viruses.     

Survivability and β‐galactosidase activity of bifidobacteria stored at low temperatures

Abstract

This work evaluated the ability of strains representing six species of Bifidobacterium with probiotic potential to survive and maintain β‐galactosidase activity through a two‐step, low‐temperature storage period. Cultures were also evaluated for their ability to ferment skim milk and retain viability during storage at 4°C. Bifidobacterium longum ATCC 15707, B. breve 15700, and B. bifidum 29521 maintained the greatest viabilities at > 1 x 10⁷ CFU/mL, and B. infantis 15702 maintained the highest β‐galactosidase activity at > 1 U/ml (with < 1 × 10⁵ CFU/mL) after ‐60 to 4°C storage. In fermented skim milk, B. breve 15700, B. bifidum 29521, and B. animalis 25527 tolerated a final product pH of 4.75 with > 1 × 10⁸ CFU/mL remaining after 14 days of storage at 4°C. Overall, it was found that highest levels of β‐galactosidase activities did not necessarily correlate to the highest plate‐count populations.