The discovery of phase variation by Andrewes (1922) has had a profound effect on the differentiation of Salmonella types. This phenomenon and the demonstration of heat-stable and heatlabile receptors by Weil and Felix (1920) form the basis for the modern classification of the paratyphoid group. Through the work of a number of investigators it has gradually been accepted that the motile Salmonel...

The main objective of this study was to predict mono and multiphasic growth model parameters of broilers. For this purpose daily body weights-age data of 106 male and female chickens reared under different stocking densities (GR1=11 birds/m2 , GR2=17 birds/m2 and GR3=25 birds/m2) were used. Results of mono and multiphasic (diphasic and triphasic) growth curve analyses showed that defining the g...

VASOVAGAL fainting, also called vasodepressor fainting, is a common and dramatic reaction frequently occurring as a response to an emotionally disturbing event. The pathophysiology of the faint itself has been recently reviewed by Edholm and by Sharpey-Schafer. The cardinal manifestations are low blood pressure and slow heart rate. The cardiovascular events which precede the faint have received...

Recent studies have shown that the mullitization of diphasic aluminosilicate matrices comprising transitional alumina and amorphous silica occurs via a nucleation and growth process. Nucleation is preceded by a temperature-dependent incubation period. Following this incubation period, rapid nucleation of mullite occurs, producing about 1.8 X 10" nuclei/cm3, which remains constant throughout the...

Transmembrane potentials and membrane characteristics of Stentor coeruleus were studied by means of microelectrodes and standard electrophysiological techniques. Intracellular resting potentials were found to be variable and recordable for only a brief span of time owing to the encapsulation of the recording electrodes. During this brief time span of recorded resting potentials were anamolous i...

Nine mathematical models were compared for their ability to predict daily milk yields (n = 294,986) in standard 305-d and extended lactations of dairy cows of Costa Rica. Lactations were classified by parity (first and later), lactation length (9 to 10, 11 to 12, 13 to 14, 15 to 16, and 16 to 17 mo), and calving to conception interval (1 to 2, 3 to 4, 5 to 6, 7 to 8, and 9 to 10 mo). Of the nin...