The quantum to classical crossover for a weak link capacitor

We consider a model weak link, an ultra-small capacitor subject to tunnelling, to ohmic dissipation and fed with an external displacement current. The framework we employ is the new approach of quantum state diffusion, which treats individual open quantum systems as well as being able to generate the conventional ensemble averages. We show how evidence for archetypal quantum behaviour (coherent oscillations) and archetypal classical behaviour (chaos) arises, for weak links whose parameters are related by a rather modest scaling. Interestingly, the quantum behaviour can arise for a weak link with intrinsic parameter values such that it could exhibit chaos, if it were a purely classical device.     

Collision detection methodologies for rigid body assembly in a virtual environment

In this paper, a simulated three-dimensional virtual environment is created with a virtual 3D track ball for virtual object control. We propose a new technique called HV Partition to detect accurate collision in the assembly of two polyhedral solids in virtual simulation. This is a solid interference detection methodology achieved by automatically partitioning the object into smaller solid boxes. An important advantage of this methodology compared with other approaches is that it can deal with non-convex objects. This means that mechanical components, represented by non-convex polyhedra, traversing any degree of freedom, can be used in this virtual environment. Using this HV Partition method, the precise interference between two polyhedral solid objects can be found. The HV Partition methodology is applied following initial approximate collision detection using traditional bounding box and bounding sphere methods. The smaller the number of smaller boxes, the quicker is the performance of the collision algorithm. An optimal partition method is also given to reduce the number of smaller boxes in an object.     

8088 development system programmed in C

An 8088 development system is described which combines the advantages of a personal computer (IBM PC), with high-level language support in the form of a c compiler, and a rack-based system. A suite of programs has been developed to enable the c compiler output to be converted into a form suitable for execution on the rack-based target as either ROM- or RAM-resident applications.     

Multidimensional scaling reveals two dimensions of thermal pain.

Used the individual differences scaling model of multidimensional scaling to explore the dimensions of thermal pain. 20 male undergraduates made 66 similarity judgments to all pairs of 12 different thermal stimulus intensities ranging from zero to noxious. Results reveal a 2-dimensional group stimulus space. The major dimension ordered the stimuli with respect to their intensity. This quantitative, strength-of-sensation dimension may be interpreted as indicating how weak or strong a stimulus feels, apart from any secondary qualities of warmth or pain. The 2nd dimension was related to the qualitative aspects of the stimuli and contained 2 attributes: (1) a pain attribute ranging from just detectable warmth to painful and (2) a warm–hot attribute running from just detectable warmth to hot. (21 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Phospholipase A2 and arthritis

Over the last 30 years, interest in PLA2 has grown beyond its enzymatic capacity to cleave phospholipids. It has been recognized as the rate-limiting step in the release of arachidonic acid and subsequent formation of prostaglandins, leukotrienes, and other bioactive lipids. Subsequently, PLA2 has not only been found to be present in high concentrations in inflammatory arthritis, but also to induce inflammation when injected into animals. At the same time, investigators into mechanisms of signal transduction demonstrated that a variety of cytokines including IL-1 and TNF, which are found in high concentrations in synovial fluid from patients with RA, stimulate PLA2 activity. These investigations demonstrated further the central role for PLA2 in inflammatory events, especially inflammatory arthritis. Numerous other PLA2 proteins, in addition to the low molecular weight synovial fluid/platelet enzyme, also have been characterized. Their clinical role in arthritis is yet to be elucidated. Human proteins which either inhibit or stimulate PLA2 have also been identified, characterized, and cloned. More recently, exciting investigations, primarily from biotechnology and pharmaceutical companies, into inhibitors of PLA2 have been reported. New PLA2-regulating compounds, which will hopefully move from the laboratory and through clinical trials and then be used to treat patients with arthritis, are on the horizon.