More detailed information about the s t ructure of Sperner families can be obtained by considering their level sequences. The level sequence of a family 4 , f ( ~ ) = {fi(Y)}, has f i (~) equal to the number of members of ~ with exac t ly ' / e l emen t s . Sperner 's theorem asserts tha t ~fi(2~)<_ ([~j) . A stronger restriction on the level i sequence was proved independent ly by Lubell, Yama...

In this paper we establish existence and regularity of positive solutions for a singular quasilinear elliptic system with competitive structure. The approach is based on comparison properties, a priori estimates and the Schauder’s …xed point theorem.

The tissue reaction following orthodontic tooth movement and its relation to functional infl uences has been a problem frequently discussed during the last 15 years. Earlier studies on tissue changes, those made by Sandstedt and others, did not include the functional factor to any great extent. As we know, it was Häupl (1938) , Häupl and Psansky (1938) and Eschler (1939) , who called attention ...

We prove some tradeoos between the size and depth of algebraic formulae. In particular, we show that, for any xed > 0, any algebraic formula of size S can be converted into an equivalent formula of depth O(log S) and size O(S 1+). This result is an improvement over previously-known results where, to obtain the same depth bound, the formula-size is (S), with 2.

Under multiple schedules of reinforcement, previous research has generally observed tolerance to the rate-decreasing effects of cocaine that has been dependent on schedule-parameter size in the context of fixed-ratio (FR) schedules, but not under the context of fixed-interval (FI) schedules of reinforcement. The current experiment examined the effects of cocaine on key-pecking responses of Whit...

c sI A bik T 1i 1 bi fi b ju j t Wm s ii fi t Wm s i j u j t for two signals fi t and u j t , as c sI A bik T 1i bi Wm s ii and c sI A bik T 1i 1b j Wm s i j, for ii c A bik T 1i n bi and i j c A bik T 1i n 1b j as verified in the proof. When (A, bi, c) is not in the controllable canonical form realization but (A, bi, c) and (A, b j, c) have the same relative degree n , there is a transformatio...

We consider the problem of computing the power of some usual F transforms of the Wilks U, Hotelling-Lawley T, and Pillai V statistics for testing H0: CBA = Œ0 under the multivariate general linear model, Y = XB + ‰ , where the rows of ‰A are taken as independent N(0, Í) random vectors. Keeping all these matrices at full rank, let C be rC × rX and A be P × rA. For determining p-values, Fi (i ∈ {...

The distribution of latencies and interresponse times (IRTs) of rats was compared between two fixed-interval (FI) schedules of food reinforcement (FI 30 s and FI 90 s), and between two levels of food deprivation. Computational modeling revealed that latencies and IRTs were well described by mixture probability distributions embodying two-state Markov chains. Analysis of these models revealed th...

This study investigates whether plasma extracts previously demonstrated to have natriuretic and antinatriferic activity have effects on vascular reactivity of rat cremaster arterioles. Plasma from hydropenic and saline-loaded dogs was subjected to Diafiltration, and eluted on a strong cation exchange column (SCX). The effects of intraarterial injections of various column fractions on constricto...