A computer program for the morphometric analysis of cell profiles.

A computer program which yields values for the volumes, surface areas, and volume/surface area ratios of cell profiles is described for use on a desktop calculator (minicomputer). This program uses standard morphometric procedures, and incorporates data obtained from electron micrographs at two levels of sampling. The main program yields values for the 'average cell volume' at the tissue level of sampling. Two options at the cellular level of sampling are also included which yield values for the volumes, surface areas and volume/surface area ratios for the organelles. The first option allows an analysis of 'whole cells' containing equatorial profiles through the nucleus, while the second option permits a 'fractional' approach using segments of the cells. Finally, some of the advantages of the two options are discussed.     

A computer program for transition life tables

A computer program is described based on the method of Mantel and Byar [1] to compare the survival experience of two groups of patients when transitions (crossovers) occur between treatment groups. The program allows for at most one transition per case and computes the Mantel-Haenszel statistic as well as an overall estimate of relative risk. Data from the Stanford Heart Transplant program [2] are used to illustrate use of the program.     

A neuron model as an universal element of self-learning networks for pattern recognition

A mathematical model of the neuron, socalled D-neuron, is proposed on the basis of some new conceptions concerning the molecular mechanism of the synaptical memory. According to these conceptions, the receptors of the neuron reception surface are divided into functional independent fields of receptors. The receptors of any field belong to corresponding membrane protein complex which contains moreover Na⁺-channels, K⁺-channels and eventually other protein subunits. Three processes are supposed to take place in any complex by its interaction with chemical transmitters: i cooperative transitions of the subunits, ii time-controlled transport of ions and iii changes of concentrations of the protein complex subunits. These processes correspond to the following information processings: i recording in the memory, ii discrimination and iii accomodation. In this paper they all are described by an idealized system of algebraic and differential equations. The proposed neuron model can account for the short- and long-term memory mechanism on the level of a single neuron as well as for the control of the neuron networks by the hormones. finally, the neuron model is presented as a universal unit of self-learning networks.     

A computer program for analyzing bivariate flow karyotypes

This article describes a computer program for analyzing bivariate flow karyotypes of human chromosomes stained with Hoechst 33258 (HO) and chromomycin A3 (CA). The karyotype first is divided into regions that contain chromosome peaks. The chromosomes that are associated with those areas are identified. The distributions in these areas then are fitted with mathematical functions of increasing complexity. The process starts by fitting a specified number of univariate Gauss functions to projections of the HO and CA distributions of each area. The final fit can include multiple bivariate Gauss functions, including a background function for debris subtraction. The results of one stage in the fitting process serve as seed values for the next, more complex step. Since the program autonomously estimates the starting values for the iterative fitting procedures, the fit results are insensitive to operator bias and the program will consistently converge to the same solutions. The resulting table of parameter values can be used to compare flow karyotypes to a reference data set.     

A computer program package for relative survival analysis

A computer program package has been constructed for use in patient survival analyses for chronic diseases based on aggregated data. The central concept of the analyses--the relative survival rate--is the ratio of the observed survival rate of the patients to the survival rate expected in a group in the general population similar to the group of patients at the beginning of the follow-up (interval), with respect to age, sex and calendar time. This quantity is used to measure patient survival adjusted for the effect of mortality attributable to the competing risks of death without employing information on causes of death of individual patients. The package contains three alternative methods of estimating the relative survival rates, two different ways of estimating the expectation of life for the patients, and five methods of testing the relative survival patterns using information on the whole follow-up period. Conventional survival and competing risk analysis can also be performed with the package. It is hoped that the package will facilitate standardization of statistical methodology and terminology in long-term survival studies for chronic diseases.     

A computer program to search for tRNA genes.

This paper describes a computer program that can find tRNA genes within long DNA sequences. The program obviates the need to map the tRNA genes.     

Glucopage: A computer program for managing diabetic pregnancy

The microcomputer is an invaluable aid in the management of diabetes mellitus because of its ability to manipulate, summarise, and produce graphical displays from blood glucose data in such a way that new trends, or the effects of changes in therapy, are more readily apparent to the clinician. Currently available software however, while adequate for most purposes, has not been written to cope with the unique problems presented by diabetic pregnancy in which large amounts of data are generated over short periods of time, insulin requirements may change rapidly, and blood glucose control must be extremely tight. We have produced a new program, GLUCOPAGE, specifically for use in the management of diabetic pregnancy. GLUCOPAGE operates in conjunction with the Ames Memory Glucometer, from which it can download data either directly or telemetrically via a modem into the host IBM PC or compatible microcomputer. Large amounts of data can be summarised in various tabular and graphical formats on screen or in printed form. A single A4-size printout, the Glucopage, provides tabular and graphical summaries of a full week's blood glucose data. Copies of the Glucopage may conveniently be filed in the case notes, given to the patient or distributed to other medical staff.     

A BASIC computer program for analyzing endpoint assays.

We present a computer program that is based on Karber's approximation of endpoint titers, written in GW-BASIC and provides an easy means for analyzing the results of dilution endpoint assays. The program provides estimates of standard error that are not possible from other statistical procedures for this type of data.     

A computer program for calculating respiratory anatomic dead space

The Fowler technique for estimating anatomic dead space (V_D - the volume of the airway conducting system) on the basis of CO₂ changes in the expired air of a single breath was adapted to computer analysis. The areas above and below the sigmoid CO₂ curve in the region of transition from inspired to alveolar concentration were simultaneously integrated (forward and backward) on a time base until the sum of the two integrated values equalled the total area representing the transition. This point on the CO₂ curve was defined as the CO₂ midpoint. Expiratory flow was then integrated with time from its beginning to the CO₂ midpoint, and the resultant volume represented V_D for that breath. The computer program was able to compensate for differences in response time between the gas monitor and the flow measuring device and was able to integrate the areas rapidly. The program provided a rapid calculation of V_D, which compared well with values calculated by tedious, manual methods.     

A computer program for maximum likelihood paired comparison rankings

We describe a program for obtaining estimates of the rank order of objects in a paired comparison experiment. The program uses Remage and Thompson's dynamic programming algorithm [3] to obtain that ranking which maximizes the likelihood function with the restriction of weak stochastic transitivity.     

A computer program for long term anticoagulation control.

A computer program is described which calculates suggested daily anticoagulant dose schedules for long term patients. This program is a part of the real-time Information System for Thrombosis Centres. The program requires only the most recent information on the patient from the Information System's data base. This information consists of the latest two measured coagulation times, the previous dose schedule, the target and limiting values set by the physician to the coagulation time, and a very limited number of parameters accounting for the patient's anticoagulation history. A simple dose-response model is used to simulate and predict a coagulation time. By comparing this prediction with the measured coagulation time the program computes the necessary adjustment in the average dose and the appointment period. It gives remarks, if necessary. The Information System is used successfully for the majority of patients of Leiden Thrombosis Centre, where it operates as a part of a real-time Hospital Information System.     

A computer program for characterizing root system branching patterns

A computer program is presented which measures the length, branching patterns and distribution of link length within a root system. The program skeletonizes digitized images of root systems, loads these images into a binary tree data structure and uses this data structure to characterize the root systems. Measurements of the root length and topological parameters of root systems of Senecio vulgaris made by hand and by computer program were linearly related, with r² values greater than 0.99 in all cases.