We studied the potassium channel in the basolateral membrane of the rat proximal convoluted tubule as affected by cyclosporine A. Proximal convoluted tubules were dissected from the rat kidney under a stereoscopic microscope, without a preliminary enzyme treatment. The standard configuration for single-channel tight seal patch-clamp technique
was used to record channel currents. A small conductance, stretch-sensitive potassium channel could be observed spontaneously in most of the cell-attached patches as the gigaohm seal was formed. In the inside-out configuration, channel activity was diminished. The K+
channel appeared to be an inward rectifier. The limiting inward slope
conductance was 28.3±1.7 pS (Vp was between 40 mV and 80 mV, n=6) and the outward chord conductance was 5.6±0.3 pS (Vp was between -40 and -60 mV, n=5). The open dwell time constants of the potassium channel were 0.524 ms and 5.087 ms, while the closed dwell time constants were 1.029 ms and 16.500 ms. The opening probability of the
channel decreased when the extracellular fluid was acidified. Cyclosporine A had no significant effect on the potassium channel of the proximal tubular cell in the basolateral membrane at concentrations of 10 and 50 μg/ml, while at 100 μg/ml, it decreased the opening probability.
Let $f$ be a transcendental meromorphic function. We propose a number of results concerning zeros and fixed points of the difference $g(z)=f(z+c)-f(z)$ and the divided difference $g(z)/f(z)$.
The paper extends the results given by M. Křížek and L. Somer, {\it On a connection of number theory with graph theory}, Czech. Math. J. 54 (129) (2004), 465--485 (see [5]). For each positive integer $n$ define a digraph $\Gamma (n)$ whose set of vertices is the set $H=\{0,1,\dots ,n - 1\}$ and for which there is a directed edge from $a\in H$ to $b\in H$ if $a^3\equiv b\pmod n.$ The properties of such digraphs are considered. The necessary and the sufficient condition for the symmetry of a digraph $\Gamma (n)$ is proved. The formula for the number of fixed points of $\Gamma (n)$ is established. Moreover, some connection of the length of cycles with the Carmichael $\lambda $-function is presented.
If $X$ is a convex surface in a Euclidean space, then the squared intrinsic distance function $\mathop {{\rm dist}}^2(x,y)$ is DC (d.c., delta-convex) on $X\times X$ in the only natural extrinsic sense. An analogous result holds for the squared distance function $\mathop {{\rm dist}}^2(x,F)$ from a closed set $F \subset X$. Applications concerning $r$-boundaries (distance spheres) and ambiguous loci (exoskeletons) of closed subsets of a convex surface are given.
Properties of sup-∗ compositions of fuzzy relations were first examined in Goguen [8] and next discussed by many authors. Power sequence of fuzzy relations was mainly considered in the case of matrices of fuzzy relation on a finite set. We consider sup-∗ powers of fuzzy relations under diverse assumptions about ∗ operation. At first, we remind fundamental properties of sup-∗ composition. Then, we introduce some manipulations on relation powers. Next, the closure and interior of fuzzy relations are examined. Finally, particular properties of fuzzy relations on a finite set are presented.
Intracellular recordings show that some hypothalamic neurones are inherently warm sensitive and have branching dendrites that alow synaptic integration of different afferent pathways.
The concept of a relatively pseudocomplemented directoid was introduced recently by the first author. It was shown that the class of relatively pseudocomplemented directoids forms a variety whose axiom system contains seven identities. The aim of this paper is three-fold. First we show that these identities are not independent and their independent subset is presented. Second, we modify the adjointness property known for relatively pseudocomplemented semilattices in the way which is suitable for relatively pseudocomplemented directoids. Hence, they can also be considered as residuated structures in a rather modified version. We also get two important congruence properties, namely congruence distributivity and 3-permutability valid in the variety V of relatively pseudocomplemented directoids. Then we show some basic results connected with subdirect irreducibility in V. Finally, we show another way how to introduce pseudocomplementation on directoids via relative pseudocomplementation.
In this paper we study some properties of the subsemigroups of the bicyclic monoid B, by using a recent description of its subsemigroups. We start by giving necessary and sufficient conditions for a subsemigroup to be finitely generated. Then we show that all finitely generated subsemigroups are automatic and finitely presented. Finally we prove that a subsemigroup of B is residually finite if and only if it does not contain a copy of B.
We study the unique information function UI(T:X∖Y) defined by Bertschinger et al. [4] within the framework of information decompositions. In particular, we study uniqueness and support of the solutions to the convex optimization problem underlying the definition of UI. We identify sufficient conditions for non-uniqueness of solutions with full support in terms of conditional independence constraints and in terms of the cardinalities of T, X and Y. Our results are based on a reformulation of the first order conditions on the objective function as rank constraints on a matrix of conditional probabilities. These results help to speed up the computation of UI(T:X∖Y), most notably when T is binary. Optima in the relative interior of the optimization domain are solutions of linear equations if T is binary. In the all binary case, we obtain a complete picture of where the optimizing probability distributions lie.