Deoxyribonuclease: detection with a three-hour test

A three-hour test has been developed to determine deoxyribonuclease activity of Enterobacteriaceae and staphylococci. The test is inexpensive and easy to perform. The rapid deoxyribonuclease test and the conventional method showed complete agreement with the strains tested.     

Thermally Induced Gelation of Native and Modified Egg White-Rheological Changes During Processing; Final Strengths and Microstructures

The heat-induced gelation of native egg white (EW) and egg white modified with succinic anhydride (SEW) or oleic acid (OEW), by addition of 15 moles of reagent/50000g protein, was evaluated. Rigidity modulus (G) and mechanical energy damping were continuously monitored during heating of the samples from 5 - 95°C in a nondestructive temperature-controlled thermal scanning rigidity monitor (TSRM). A measurable increase in G and decrease in energy damping were observed at lower temperatures for OEW than for EW. In SEW the measurable rheological transitions occurred at the highest temperature ranges. Failure strength of the cooked products (gels) evaluated using torsion and uniaxial compression tests revealed large differences due to treatments. Micrographs of gels showed apparent structural differences among treatments.     

Effects of temperature, photoperiod, and thiourea on the thyroid of the woodrat (Neotoma micropus)

Female inbred F344 rats fed diets containing high levels of beef protein and fat or high levels of soybean protein and corn oil and treated with 1,2-dimethylhydrazine had a greater incidence of colon tumours than did rats fed diets that had normal levels of such components and were treated similarly. The source of fat and protein had no major influence on the incidence of colon tumors.     

Strength of Hot-Pressed Silicon Nitride After High-Temperature Exposure

Short-term exposure of hot-pressed silicon nitride to temperatures greater than 800°C in an oxidizing atmosphere causes an increase in the room-temperature strength and eliminates the truncated strength distribution produced by room-temperature proof-testing. Acid-etching the proof-tested samples restores the original truncated distribution. These strength changes are shown to be related to the formation of a glassy phase on the surface that smooths out the preexisting machining flaws. More extensive, long-term oxidation produces surface pits that lead to an irreversible change in strength     

SOLUBLE PEROXIDASE ACTIVITY IN PURPLE, GREEN AND WHITE EGGPLANTS

Soluble peroxidase activity extracted from purple, green and white eggplants (Solanum melongena L.) was measured spectrophotometrically. Activity was significantly higher in the white variety than in the other two. The isozyme patterns were compared by polyacrylamide gel electrophoresis. The purple and green had 3 major isozyme bands between 0.8 and 0.9 Rf while the white contained 2. Only the white and purple cultivars contained bands between 0.06 and 0.3 and 0.6 and 0.7 Rf.     

Sphere flattening with application to the moderate plastic compaction of regular sphere assemblages

The problem of flattening a rigid/perfectly plastic sphere under a uniaxial compressive loading is solved. This solution gives approximate relations between contact force and contact area analogous to the Hertz classical solution for an elastic sphere. It is used as the basis for studying the moderate plastic compaction of arrays of spheres. The simple cubic and hexagonal close-packed arrangements, representing the extremes of initial density, are treated for various deformation conditions. Pressure—porosity expressions are derived and are used in several comparisons with available experimental data. The theory shows, as expected, that the work required to achieve a given compressive strain is less in the simple cubic arrangement than in the hexagonal close-packed arrangement, and less for uniaxial compression than for biaxial or triaxial compression.     

Some aspects of the psychological representation of speech sounds

If one listens to a meaningless syllable that is repeated over and over, he will hear it undergo a variety of changes that can be described systematically in terms of reorganization of the phones constituting the syllable and changes in a restricted set of phonetic distinctive features. When the repeated syllable is followed by a different syllable but in the same voice, the new (test) syllable will be misperceived in a manner related to the perceptual misrepresentation of the repeated syllable. In the present experiment subjects (N = 24) listened to 72 different experimental sequences of repeated syllables in a male voice followed by test syllables in a female voice. Identification of penultimate and test syllables was independent and in no instance were the phone constituting the syllables reorganized. These results are interpreted as evidence against both auditory and phonetic feature detector theories of speech perception.