A series of experiments was performed to determine whether sign-tracking would occur in rats with intravenous (i.v.) cocaine as the unconditioned stimulus. In Experiment 1, a retractable lever paired with food produced strong sign-tracking, but a lever paired with one of three doses of i.v. cocaine did not elicit any approach or contact behavior. Experiment 2 demonstrated that doses of cocaine ...

Extending the body with a tool could imply that characteristics of hand movements become characteristics of the movement of the effective part of the tool. Recent research suggests that such distal shifts are subject to boundary conditions. Here we propose the existence of three constraints: a strategy constraint, a constraint of movement characteristics, and a constraint of mode of control. We...

Myosin V is a two-headed molecular motor that binds six light chains per heavy chain, which creates unusually long lever arms. This motor moves processively along its actin track in discrete 36-nm steps. Our model is that one head of the two-headed myosin V tightly binds to actin and swings its long lever arm through a large angle, providing a stroke. We created single-headed constructs with di...

Myosins are actin-based motors that are generally believed to move by amplifying small structural changes in the core motor domain via a lever arm rotation of the light chain binding domain. However, the lack of a quantitative agreement between observed step sizes and the length of the proposed lever arms from different myosins challenges this view. We analyzed the step size of rat myosin 1d (M...

Flap gates are commonly used at the end of pipe drains and pump outlets to prevent backflows of water and entry of small animals. Flap gates are relatively inexpensive, with low maintenance costs, but can trap debris in their hinge systems. Many texts refer to studies performed on flap gates at the University of Iowa in 1936, which may be limited in value because they are for specific “lightwei...

We present a framework to automatically model and reconstruct buildings in a dense urban area. Our method is robust to noise and recovers planar features and sharp edges, producing a water-tight triangulation suitable for texture mapping and interactive rendering. Building and architectural priors, such as the Manhattan world and Atlanta world assumptions, have been used to improve the quality ...

From 1996 to 2000, 11 adolescents with hip joint arthritis secondary to osteonecrosis or idiopathic chondrolysis were treated with articulated hinged distraction arthroplasty. Indications for surgery were severe pain and limited ambulation. Charts and radiographs were reviewed. Clinical status was assessed preoperatively and at latest follow-up (mean 4.8 years after surgery) using criteria of p...