S tepwise refinement remains a popular approach to program-design implementation, primarily because of its flexibility. As originally proposed by Niklaus Wirth, the technique involves successively decomposing design decisions into target code. With each re6nement step, the designer must + note the interdependence of subproblems, + attempt to preserve the design’s functional correctness, and + d...

An algorithm for switchbox routing, called PACKER, is presented. In an initial phase, the connectivity of each net is established in a fast way without taking the other nets into account. In general this will give rise to conflicts (short circuits). In the second stage the conflicts are removed iteratively using Connectivity preserving local transformations (CPLT’s). They “reshape” a net by dis...

Model checking complex systems always suffers from the state explosion problem. Over the last 10 years there has been lots of researches on how to mitigate the state explosion problem. As a result, many techniques have been emerged such as absiraction, compositional reasoning, and exploiting symmetry. In line with these efforts, this paper proposes stepwise model checking which exploits hierarc...

M énière’s disease is characterised by recurrent attacks of vertigo accompanied by fluctuating sensorineural hearing loss, tinnitus and a sense of aural fullness. Prosper Ménière in 1861 correctly attributed the attacks to a disorder of the inner ear, suggesting that the mechanism of causation could be similar to migraine or inner ear vasospasm, a differential diagnosis which is still relevant ...

In this talk we discuss the predator-prey models with harvesting of the prey. We briefly introduce the basic Lotka-Volterra predator-prey model and different harvesting strategies. Then we focus on two types of harvesting functions, and combine them with two types of predator-prey models, one with exponential growth of the prey and the other one with logistic growth of the prey. For each type o...

Alcohol concentration dependences of photoinduced charge separation (CS) reaction of zinc tetraphenyl-porphyrin (ZnTPP) and duroquinone (DQ) were investigated in benzonitrile by a nanosecond laser flash photolysis technique. The photoinduced CS reaction was accelerated by the addition of alcohols, whereas the addition of acetonitrile caused little effect on the CS reactions. The simple theory w...

Voltage-gated potassium channels elicit membrane hyperpolarization through voltage-sensor domains that regulate the conductive status of the pore domain. To better understand the inherent basis for the open-closed equilibrium in these channels, we undertook an atomistic scan using synthetic fluorinated derivatives of aromatic residues previously implicated in the gating of Shaker potassium chan...

RNA viruses possess the potential for rapid evolution and serve as excellent models to test evolutionary theory. Molecular phylogenetic analysis of the P gene for a larger number of diverse natural isolates of vesicular stomatitis virus reveals no evidence for a molecular clock but instead shows a stepwise evolutionary pattern unlike that ever seen before. Each step out from the tree's ancestra...

Carbon dioxide and two equivalents of Na(OCP) form, in an equilibrium reaction, a CO2 adduct of the composition Na2(P2C3O4). The anion of this salt, [O2C-P(CO)2P](2-), is built up by a four-membered 1,3-diphosphetane-2,4-dione ring and a carboxylate unit attached to one of the phosphorus atoms. A remarkable π-delocalization was observed within the OCPCO moiety. The stepwise reaction mechanism l...

F1-ATPase hydrolyzes ATP into ADP and Pi and converts chemical energy into mechanical rotation with exceptionally high efficiency. This energy-transducing molecular motor increasingly attracts interest for its unique cellular functions and promising application in nanobiotechnology. To better understand the chemomechanics of rotation and loading dynamics of F1-ATPase, we propose a computational...