Exponential Rate Of Decrease Research Articles

A nonlocal approach for asymptotic memoryless detection theory (Corresp.)

Previous literature on detector design has presented many tractable results using efficacy as a performance functional, which is a small signal or local approach. Some nonlocal issues of memoryless detection are considered. We argue that the asymptotic exponential rate of decrease of error probabilities, or Bayes risk, provides the appropriate asymptotic measure of performance. A main contribution is the development of an approximation for nonlocal design that retains the tractability of the efficacy approach. We have proved the local consistency of our approximation. Also, as a consequence of the analysis, new proofs for Pitman-Noether-like theorems have been obtained.

Radioimmunologic assessment of the level of circulating LH antibodies after passive immunization of the rat: relation to the level of LH secretion.

A double antibody radioimmunologic technique was used to estimate circulating levels of "free" LH antibodies (Ab) (i.e., Ab available for binding to radioiodinated rat LH in vitro) after a single injection of an equine antiserum to bovine LH (LH-AS) into cyclic (diestrus-1), early pregnant (d 6 or d 8), short-term (1 d) or long-term (12 d) ovariectomized, or 8-d hypophysectomized female rats. In both cyclic and pregnant rats given 0.5 ml LH-AS sc the blood Ab levles peaked 1 to 2 days after injection and then decreased exponentially (half-time: 14.6-17.0 h) and equally: vaginal estrus also appeared in the cyclic and the aborting pregnant rats on the 6th day, and ovulation on the 7th day after LH-AS treatment, when the blood levels had fallen to very low values. The rate of exponential decrease in blood Ab levels was not affected by other routes of administration (iv or ip) of LH-AS, or by sc doses of 1.0 or 0.25 ml, although the peak levels and their duration were related to dose and route of administration. Ovariectomy significantly increased the rate of exponential Ab decrease (half-time: 9.8 h in rats tested 12 days after operation) and hypophysectomy markedly diminished it (half-time: 63.0 h in rats tested 8 days after operation). Daily treatment of hypophysectomized rats with 20 mu/day of ovine LH from the time of LH-AS injection increased the rate of exponential Ab decrease to one approaching that of the intact rats (half-time: 20.5 h). Free LH antibodies thus seem to disappear from the circulation at a rate proportional to the amount of LH in the circulation.

Influence of amorphous environment on magnetic structure

The influence of disordered medium on the magnetic structure of crystalline clusters is discussed. In a plate-like crystalline cluster with localized moments the disordered magnetic environment leads to preference of a spiral magnetic structure over the antiferromagnetic collinear ordering that would be otherwise realized. By the numerical solution of a specific model qualitative information was obtained about the influence of the exponential rate of decrease of the exchange interaction, plate thickness and degree of disorder of the medium on the magnetic structure of the cluster.

Transport of biosynthetic intermediates: regulation of homoserine and threonine uptake in Escherichia coli.

Homoserine is transported by a single system that it shares with alanine, isoleucine, leucine, phenylalanine, threonine, valine and perhaps cysteine, methionine, serine, and tyrosine. We investigated the regulation of this transport system and found that alanine, isoleucine, leucine, methionine, and valine each repress the homoserine-transporting system. From the concentration resulting in 50% repression of this transport system and the maximal amount of repression, we ranked the amino acids according to their effectiveness in repressing homoserine transport (in decreasing order): leucine>methionine>alanine>valine>isoleucine. The exponential rate of decrease in transport capacity after leucine addition equals the exponential growth rate of the culture, and protein synthesis is necessary for the derepression seen when leucine is removed. Threonine, in addition to using the above system, is transported by a second system shared with serine. We present further evidence for this serine-threonine transport system and show that it is not regulated like the homoserine-transporting system.

A numerical solution for irrotational flow over a mountain barrier

The “relaxation method” is applied to Pockels' equation for a particular case of flow over a given mountain profile with boundary conditions specified to be that the isopleths of velocity potential be normal to the top and bottom boundaries. The values of vertical velocity thus found are then compared with those from Pockets' solution for the same profile and with the exponential rate of decrease assumed by Bjerknes [1940], The different methods give quite different results, the principal difference being that at higher elevations (five to ten kilometers) the vertical velocities computed by the relaxation method are larger than those computed by Bjerknes' method and much smaller than those computed by Pockels' method. The large disagreement between these results shows the dangers involved in a purely theoretical approach to the problem. Evidently more observations of vertical velocities in regions of rough orography are needed before the various theories can be evaluated.