Kinesis: Locomotor behavior not involving a steering reaction, but in which there may be a turning random in direction. It includes orthokinesis, the rate of movement and klinokinesis, the amount of turning, which are related to the intensity of stimulation.Rheiformes: An order of large, long-necked, long-legged, flightless birds, found in South America. Known as rheas, they are sometimes called American ostriches, though they are in a separate order from true OSTRICHES.Beak: In some animals, the jaws together with their horny covering. The beak usually refers to the bill of birds in which the whole varies greatly in form according of the food and habits of the bird. While the beak refers most commonly to birds, the anatomical counterpart is found also in the turtle, squid, and octopus. (From Webster, 3d ed & Storer, et al., General Zoology, 6th ed, p491, 755)Palaeognathae: A superorder of large, mostly flightless birds, named for their distinctive PALATE morphology. It includes the orders Apterygiformes, Casuriiformes, Dinornithiformes, RHEIFORMES; STRUTHIONIFORMES and Tinamiformes.Skull: The SKELETON of the HEAD including the FACIAL BONES and the bones enclosing the BRAIN.Color: The visually perceived property of objects created by absorption or reflection of specific wavelengths of light.Endocardium: The innermost layer of the heart, comprised of endothelial cells.Echocardiography, Doppler, Color: Echocardiography applying the Doppler effect, with the superposition of flow information as colors on a gray scale in a real-time image.Dobutamine: A catecholamine derivative with specificity for BETA-1 ADRENERGIC RECEPTORS. It is commonly used as a cardiotonic agent after CARDIAC SURGERY and during DOBUTAMINE STRESS ECHOCARDIOGRAPHY.Diastole: Post-systolic relaxation of the HEART, especially the HEART VENTRICLES.Ventricular Function, Left: The hemodynamic and electrophysiological action of the left HEART VENTRICLE. Its measurement is an important aspect of the clinical evaluation of patients with heart disease to determine the effects of the disease on cardiac performance.Feasibility Studies: Studies to determine the advantages or disadvantages, practicability, or capability of accomplishing a projected plan, study, or project.Echocardiography: Ultrasonic recording of the size, motion, and composition of the heart and surrounding tissues. The standard approach is transthoracic.Biomechanical Phenomena: The properties, processes, and behavior of biological systems under the action of mechanical forces.Image Processing, Computer-Assisted: A technique of inputting two-dimensional images into a computer and then enhancing or analyzing the imagery into a form that is more useful to the human observer.