An interactive microcomputer program for the computation of most probable number

An interactive computer program for the rapid computation of Most Probable Numbers (MPN) with 95% confidence intervals and goodness-of-fit, is presented. The program, written in ‘MICROSOFT BASIC’ employs an iterative algorithm based on a modification of the Newton-Raphson method and accomodates any number of replicates up to ten dilutions. It is applicable to most microcomputers with little or no modification. Since the computed MPN, confidence interval,a nd goodness-of-fit tests are displayed simultaneously, MPN tables are no longer required.     

An improved surface-based method for DNA computation

DNA computing is a novel method for solving a class of intractable computational problems, in which the computing time can grow exponentially with problem size. Up to now, many accomplishments have been achieved to improve its performance and increase its reliability, among which a surface-based method is an efficient candidate. In this paper, the surface-based approach proposed by Liu, Q., Wang, L., Frutos, A.G., Condon, A.E., Corn, R.M., and Smith, L.M., 2000, DNA computing on surfaces. Nature 403, 175-179 is analyzed and an improved surface-based method for DNA computation (i.e. the hybrid DNA/optical computing method) is proposed. Compared with Liu et al.'s approach, our method has some significant advantages such as low cost, short operating time, reusable surface and simple experimental steps. Moreover, the concept of combining easily patterned DNA computing steps with equally parallel, but generally uniform and not easily patterned optical computing steps is an important new direction.     

An exact method for the computation of the connectivity of random nets

The problem of finding the “weak connectivity” of a random net is reduced to one involving a Markov process. This provides a mathematically exact treatment of the problem which had previously been treated by an approximation, whose justification was not rigorous. The exact method allows in principle not only the calculation of the “weak connectivity”, but also of the “strong connectivity”, and, in general, the probability that from a randomly selected neuron in the net there exist paths to a specified number of neurons. The computations become exceedingly involved for large nets.     

An image-interpolation technique for the computation of optic flow and egomotion

 A technique for measuring the motion of a rigid, textured plane in the frontoparallel plane is developed and tested on synthetic and real image sequences. The parameters of motion – translation in two dimensions, and rotation about a previously unspecified axis perpendicular to the plane – are computed by a single-stage, non-iterative process which interpolates the position of the moving image with respect to a set of reference images. The method can be extended to measure additional parameters of motion, such as expansion or shear. Advantages of the technique are that it does not require tracking of features, measurement of local image velocities or computation of high-order spatial or temporal derivatives of the image. The technique is robust to noise, and it offers a simple, novel way of tackling the ‘aperture’ problem. An application to the computation of robot egomotion is also described. Received: 3 September 1993/Accepted in revised form: 16 April 1994     

An endogenous motor program for sand crab uropods

A stereotyped pattern of spontaneous, rhythmic bursting in motoneurons of three prinicipal uropod muscles in the sand crab Emerita analoga has been recorded from a deafferented chain of the foru most-posterior abdominal ganglia. This endogenous motor program resembles the electromyogram pattern recorded from return-stroke and power-stroke muscles in swimming crabs in that (1) latencies of power-stroke bursts and burst periods are positively correlated with each other and (2) durations of power-stroke bursts are brief and mearly invarient. The endogenous program differs from the electromyogram pattern in having longer periods and return-stroke bursts which are brief and sporadic. The neural oscillator underlying the endogenous motor program, therefore, appears to drive the power stroke. Circumstantial evidence suggests that it may also inhibit return-stroke motoneurons concurrently with excitation of the power-stroke excitor.     

A microcomupter program for the computation of free energy of the secondary structure of RNA oligomers by Ninio's rules

An interactive microcomputer program for the rapid computation of the free (ΔG) of the secondary structure of RNA molecules is presented. The program assigns free energies (in kcal/mol) to helices; bulge, internal, and multi-branch loops; hairpins; unparied, and G:C termini according to Ninio's rules, and displays a running total during computation. It is written in ‘Microsoft Basic’ and is apllicable to virtually any Basic system with no modification. The program enables rapid bench-top determinations of free energies attributable to secondary structure features of RNA oligomers, and eliminates both the tedium and risk of error associated with manual calculations.     

An endogenous motor program for sand crab uropods.

A stereotyped pattern of spontaneous, rhythmic bursting in motoneurons of three principal uropod muscles in the sand carb Emerita analoga has been recorded from a deafferented chain of the four most-posterior abdominal ganglia. This endogenous motor program resembles the electromyogram pattern recorded from return-stroke and power-stroke muscles in swimming crabs in that (1) latencies of power-stroke bursts and burst periods are positively correlated with each other and (2) durations of power-stroke bursts are brief and nearly invarient. The endogenous program differs from the electromyogram pattern in having longer periods and return-stroke bursts which are brief and sporadic. The neural oscillator underlying the endogenous motor program, therefore, appears to drive the power stroke. Circumstantial evidence suggests that it may also inhibit return stroke motoneurons concurrently with excitation of the power-stroke excitor.     

An enhanced rate-based emission trading program for NOX: the Dutch model

Since 1997 government and industry in The Netherlands have been engaged in intensive policy discussions on how to design an emission trading program that would satisfy the Government's policy objectives within the national and international regulatory framework and accommodate industry's need for a flexible and cost-effective approach. Early on in the discussion the most promising solution was a rate-based approach, which dynamically allocated saleable emission credits based on a performance standard rate and actual energy used by facilities. All industrial facilities above a threshold of 20 MWth would be judged on their ability to meet this performance rate. Those "cleaner" than the standard can sell excess credits to others with an allocation that is less than their actual NOX emission. With some changes in law, such a design could be made to fit well into the national and EU legislative framework while at the same time uniquely meeting industry's requirement of flexibility toward economic growth and facility expansion. (An analysis of the legislative changes required will be given in a separate paper by Chris Dekkers.) However, the environmental outcome of such a system is not as certain as under an absolute emission cap. At the request of the Netherlands Ministry of Housing, Spatial Planning and the Environment (VROM), Automated Credit Exchange (ACE), in close cooperation with the working group of government and industry representatives introduced a number of features into the Dutch NOX program allowing full exploitation of market mechanisms while allowing intermediate adjustments in the performance standard rates. The design is geared toward meeting environmental targets without jeopardizing the trading market the program intends to create. The paper discusses the genesis of the two-tier credit system ACE helped to design, explains the differences between primary (fixed) and secondary (variable) credits, and outlines how the Dutch system is expected to function once implemented in 2004. The paper also discusses the market trading simulation held in early 2001 to assess and test the trading program, and reviews also the current status of the market program development.