To understand shapes and movements of cells undergoing lamellipodial motility, we systematically explore minimal free-boundary models of actin-myosin contractility consisting of the force-balance and myosin transport equations. The models account for isotropic contraction proportional to myosin density, viscous stresses in the actin network, and constant-strength viscous-like adhesion. The cont...

Chemotaxis of spermatozoa to female gonophores has been shown to occur in Campanularia, Tubularia and other hydroids (Miller, 1966 a, b). Cinemicrographic records of the movements of Campanularia spermatozoa in the vicinity of female gonophores or of glass capillary pipettes containing extracts of female hydranths have shown that chemotactic aggregation of the spermatozoa occurs because the spe...

The nematode Caenorhabditis elegans migrates toward a preferred temperature on a thermal gradient. A candidate neural network for thermotaxis in C. elegans has been identified, but the behavioral strategy implemented by this network is poorly understood. In this study, we tested whether thermal migration is achieved by modulating the probability of turning behavior, as in C. elegans chemotaxis....

We develop a model for anguilliform (eel-like) swimming as an elastic rod actuated via time-dependent intrinsic curvature and subject to hydrodynamic drag forces, the latter as proposed by Taylor (in Proc Roy Proc Lond A 214:158-183, 1952). We employ a eometrically exact theory and discretize the resulting nonlinear partial differential evolution both to perform numerical simulations, and to co...

Egg turning behavior is an important determinant of egg hatchability, but it remains relatively understudied. Here, we examined egg turning rates and egg temperatures in Forster's terns (Sterna forsteri). We used artificial eggs containing a data logger with a 3-D accelerometer, a magnetometer, and a temperature thermistor to monitor parental incubation behavior of 131 tern nests. Overall, adul...

Buspirone, a partial agonist of 5-hydroxytryptamine autoreceptors, selectively blocks presynaptic nigrostriatal D2 dopamine (DA) autoreceptors. At doses which antagonised action of apomorphine in biochemical presynaptic nigrostriatal D2 DA autoreceptor test systems buspirone neither induced catalepsy nor antagonised apomorphine-induced turning behaviour in rats indicating that at these doses bu...

Time-lapse videotape recordings of polymorphonuclear leukocytes (PMNs) from clot preparations were used to quantify the locomotive behavior of individual PMNs from normal subjects. Tracings derived from the videotapes allow one to quantify multiple parameters of the locomotive behavior of PMNs--direction, distance, rate, and angle of turn. The results obtained are reproducible from subject-to-s...

CONTENTS 1. Introduction 230 2. Concepts of the functional role of striatal dOpaminergic activity 231 2.1. Introduction 231 2.2. The behavioural actions of dopamine in the striatum: unitary or diverse? 231 2.3. Regional differences in the striatal functions revealed by the actions of dopamine 232 2.4. The side to which the striatum's behavioural effects are referred 232 2.4.1. The traditional v...

in this paper, we investigate the canonical property of solutions of a system of differentialequations having a singularity and turning point of even order. first, by a replacement, we transform thesystem to the sturm-liouville equation with a turning point. using the asymptotic estimates for a specialfundamental system of solutions of sturm-liouville equation, we study the infinite product rep...

Lubricant and coolant can improve surface roughness in machining. In addition of ecological harms, thermal shock of coolant or lubricant may affect the surface integrity especially on surface residual stresses and micro-crack nucleation. Dry machining is ecologically desirable and it is considered as a necessity for manufacturing enterprises in the recent years. 55Cr3 steel grade is steel with ...