Decreases in the size of the multifidus muscle have been consistently documented in people with low back pain. Recently, ultrasound imaging techniques have been used to measure contraction size of the multifidus muscle, via comparison of the thickness of the muscle at rest and on contraction. The aim of this study was to compare both the size (cross-sectional area, CSA) and the ability to volun...

The following conjecture generalizing the Contraction Mapping Theorem was made by Stein in [9]: Let (X, ρ) be a complete metric space and let F = {T1, . . . , Tn} be a finite family of self-maps of X. Suppose there is a constant γ ∈ (0, 1) such that for any x, y ∈ X there exists T ∈ F with ρ(T (x), T (y)) ≤ γρ(x, y). Then some composition of members of F has a fixed point. In this paper we disp...

The changes in conformation of F-actin induced by the binding of the glycolytic enzyme lactate dehydrogenase were studied in myosin-free single ghost muscle fibres. The formation of the lactate dehydrogenase-F-actin complex was accompanied by changes in the parameters of intrinsic (tryptophan) and extrinsic (rhodaminyl-phalloin) polarized fluorescence of ghost muscle fibre F-actin. Lactate dehy...

Phasic contractions of collecting lymphatic vessels aid in the centripetal propulsion of lymph. The numerical model published in PNAS by Kunert et al. (1) describes how two “complementary feedback loops” involving Ca and nitric oxide (NO) interact to drive the phasic contraction/relaxation cycle of lymphatic smooth muscle. The cycle is proposed to be initiated by a stretchinduced rise in lympha...

Electrically conditioned skeletal muscle can provide the continuous power source for cardiac assistance devices. Optimization of the available sustained power from in vivo skeletal muscle requires knowledge of its metabolic utilization and constraints. A thermistor-based technique has been developed to measure temperature changes and to provide a relative estimate for metabolic utilization of i...

Bradykinin (BK) induces fibroblast contraction but the structural changes and intracellular mechanisms involved have not been completely explored. We stimulated HFL-1 fibroblasts with BK to assess: 1) fibroblast contractility; 2) the role of α-smooth muscle actin (SMA) in contraction by small interfering RNA (siRNA); 3) α-SMA protein expression; 4) α-SMA and F-actin structure; 5) intracellular ...

Humans perform rhythmic, locomotor movements with the arms and legs every day. Studies using reflexes to probe the functional role of the CNS suggest that spinal circuits are an important part of the neural control system for rhythmic arm cycling and walking. Here, by studying motor evoked potentials (MEPs) in response to transcranial magnetic stimulation (TMS) of the motor cortex, and H-reflex...

F Bhadrakom, 1 and Helmer have employed spirally cut strips of rabbit aorta in a bioassay method for estimation of urinary levels of catechol amines. In attempting to use this method for determination of adrenal venous plasma levels of epinephrine and norepinephrine, the possibility arose that adrenal steroids might alter the contraction of rabbit aortic smooth muscle produced by these eatechol...

We initiate the study of the Bipartite Contraction problem from the perspective of parameterized complexity. In this problem we are given a graph G and an integer k, and the task is to determine whether we can obtain a bipartite graph from G by a sequence of at most k edge contractions. Our main result is an f(k) n time algorithm for Bipartite Contraction. Despite a strong resemblance between B...

The effect of chloroform soluble fraction (F-A) of twigs of Sarcostemma brevistigma on contractions induced by KCl, histamine, and acetylcholine in the isolated guinea pig ileum and taenia coli smooth muscles has been evaluated. F-A (19.5 microg/ml) significantly inhibited the contraction induced by 40 mM KCl to the extent of 87.6% in the isolated guinea pig ileum. In the isolated guinea pig il...