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.
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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.
Analysts must deal frequently with missing data in multivariate analysis. In such cases, estimating the covariance maxtrix V of the dependent variables usually involves initial estimation and iterative adjustment of imputed missing data values, and/or smoothing of an estimate V which is not necessarily positive semi-definite. This paper presents an alternative procedure for computing estimates of relevant multivariate parameters in situations where missing data occur at random and with small probability. MISCAT is a computer program which computes multivariate ratio estimates of the means and a corresponding positive semi-definite estimate of the covariance matrix. It is an extension of GENCAT, which is a program for the generalizaed least squares analysis of categorical data. Thus, one advantage of dealing with missing data in this manner is that variation among the ratio estimates may be conveniently analyzed within MISCAT using asymptotic regression methodology, provided that sample sizes are sufficiently large. An example is given to illustrate such analysis for longitudinal data from a multicenter clinical trial.
A FORTRAN computer program was developed to calculate recombination values from F2 data. The input to the program is data on codominant alleles in any number of F2 families segregating for any number of loci, the limit being applied by the computer's memory capacity. For each pair of loci, regardless of the number of segregating progenies used, one recombination value is estimated by the method of maximum likelihood and reported with its standard error. In cases in which more than one family is used for the estimation, the chi-square for the homogeneity of the data also is reported.
Presented is a computer program designed to convert any given set of exposure factors sequentially into another, yielding either an equivalent photographic density or one increased or decreased by a specifiable proportion. In addition to containing the wherewithal with which to manipulate a set of exposure factors, the facility to print hard (paper) copy is included enabling the results to be pasted into a notebook and used at any time. This program was originally written as an investigative exercise into examining the potential use of computers for practical radiographic purposes as conventionally encountered. At the same time, its possible use as an educational tool was borne in mind. To these ends, the current version of this program may be used as a means whereby exposure factors used in a diagnostic department may be altered to suit a particular requirement or may be used in the school as a mathematical model to describe the behaviour of exposure factors under manipulation without patient exposure.
A computer program has been written which performs a stepwise selection of variables for logistic regression using maximum likelihood estimation. The selection procedure is based on likelihood ratio tests for the coefficients. These tests are used in a forward selection and a backward elimination at each step. The use of the program is illustrated by several examples.
A test library composed of the ECG's of 228 patients with clinically proven myocardial infarction and 294 subjects without clinical evidence of infarction was used to assess the performance of three visual coding procedures and three computer programs designed to classify ECGs according to the Minnesota Code. The results showed that visual coding performed by one experienced senior coder tended to be more consistent than visual coding relying on two less experienced coders and arbitration of disagreements by a supervisor. There was no significant difference in coding results when only one preprocessed complex was coded in comparison with the more elaborate coding of the whole source ECG using majority rule. The coding performance of the three computer programs was similar to that of the visual coding procedures. It is concluded that computer coding of ECGs according to the Minnesota Code is feasible. Combined optimal use of automated coding and visual verification of selected items may still further improve coding precision. However, when judged against an ECG independent standard, the accuracy of all coding procedures in discriminating infarcts from non-infarcts according to the Minnesota code criteria is rather limited. 'Soft' criteria give a reasonable sensitivity with low specificity whereas the use of 'hard' criteria with adequate specificity results in a substantial drop in sensitivity.
The computer program INDEP-SELECT has been developed for selection of an optimal subset from a set of possibly informative diagnostic or prognostic variables. But the program is equally useful for other discriminant analysis or pattern recognition problems involving variable selection. The approach is probabilistic; i.e., diagnostic probabilities are assigned to a patient on the basis of the values observed on the diagnostic variables. The statistical model used is largely based on the assumption of independency between the variables, but one model-parameter, the so-called 'global association factor', is added in order to take dependency into account. The stepwise forward selection strategy of adding in each selection step a new variable to the set of already selected variables, is used. The user may choose between a number of selection criteria. Such a criterion is used in order to decide in each selection step which variable should be added. All criteria are based on measures of diagnostic or prognostic performance. INDEP-SELECT is able to handle a large number of variables, also with missing data, and a large number of patients. The program is written in ANS Standard FORTRAN, and takes relatively little computation time.
The use of the Baumgartner perfusion system allows the morphometric quantification of platelets interacting with vessel wall, however it presents the basic difficulties of morphometrical measurements. In order to facilitate the procedure of evaluation we developed a semiautomated method to avoid the complexity of the classical evaluation. Our system consists on an optical picture analysis system connected with a specially developed computer program which allows fast quantification. Simultaneously to the outlining of interacting platelets the computer program recognizes, corrects, selects and stores the information, in order to perform the final calculations as previously established. This system has been demonstrated to be as effective as the classical morphometric evaluation in the measure of platelets interacting with subendothelium. Potential sources of error such as subjectivity of the observers in selecting the class of interacting platelets are avoided. The use of this combined method opens the possibility to adapt the Baumgartner perfusion system to clinical routine and to the screening of drugs that modify platelet adherence.
A pocket computer program is described which allows rapid nutritional evaluation of hospitalized patients. Entries of anthropometric and laboratory measurements, along with the results of anergy testing allows display of the patient's nutritional assessment with degrees of depletion. Use of the program provides the clinician information which is of benefit to patient nutritional management and evaluation of significant risk potentials.
The American Animal Hospital Association Computer Program should benefit all small animal practitioners. Through the availability of well-researched and well-developed certified software, veterinarians will have increased confidence in their purchase decisions. With the expansion of computer applications to improve practice management efficiency, veterinary computer systems will further justify their initial expense. The development of the Association's veterinary computer network will provide a variety of important services to the profession.
The United States Environmental Protection Agency has published three computer programs, COMPLY, AIRDOS-PC, and CAP88-PC, to assist the regulated community in determining compliance with the Environmental Protection Agency radionuclide air emission standards. The programs calculate radiation doses from routine airborne release to the general public residing outside a nuclear facility site. They consider doses from inhalation, ingestion of contaminated food, air immersion, and ground deposition. A PC-based computer code, XOQDOQ-82, developed for the Nuclear Regulatory Commission, was also chosen to compare and evaluate dispersion results from the Environmental Protection Agency codes for the University of Missouri Research Reactor Center. Effects of building parameters, terrain conditions, and downwind distances on dispersion factors were calculated. The results of this study indicated that dispersion factors calculated using AIRDOS-PC and CAP88-PC were several times lower than those calculated using XOQDOQ-82 at all distances, and those dispersion factors calculated using COMPLY were several times lower than the XOQDOQ-82 values at distances greater than 600 m.
EPIGRAM is a computer program designed to improve access to State-level underlying cause mortality data. The program produces results for population, deaths, death rate, age-adjusted death rate, years of potential life lost (YPLL), YPLL rate, and confidence intervals. Results can be compared variously among age groups, counties, causes of death, races, regions, and years. The program's menu-driven interface facilitates the selection or modification of analysis parameters. Current selections are retained so the user can modify one parameter at a time. Based on the parameters that the user selects, the program produces a series of tables, one for each instance of a particular parameter. Each output table has columns for male, female, and both sexes combined, and an indefinite number of user-defined rows for age groups, causes of death, counties, races, regions, or years. EPIGRAM has major advantages over other methods for analyzing mortality and population data. The program uses relatively small amounts of memory and disk space, executes rapidly, is flexible, can be used by inexperienced computer users, provides online help screens and tutorials, and runs under DOS or UNIX without modification. The program currently is used to analyze mortality and population data for Texas. Although it is not currently available for distribution, support is being sought for its evaluation and possible implementation in State health departments to analyze data for other States, or other data sets, such as hospital discharge data or cancer incidence data.
The possibilities for reducing in Van de Geijn's computer program the original limitations for the size and the position within the field of shielding blocks are explored. New methods are presented which are based on experimental measurements as well as more theoretical approaches, without need for any change in the program itself. Two typical clinical examples are presented and the precision obtained critically investigated.
A computer program has been developed to aid in the brachytherapy of cancer of the cervix. Using a least-squares minimization algorithm, the program will optimize the source loading in intracavitary applicators so as to reproduce, as nearly as physical considerations allow, the dose distribution requested by the user. Applicator geometry and the relative positions of anatomical points of interest must be supplied to the program, as well as an inventory of available source strengths. Output from the computer includes the optimized source loading, time of application, and the resulting relative doses to the various user-selected points of interest.
Life table analysis has traditionally been the tool of choice in analyzing distribution of "survival" times when a parametric form for the survival curve could not be reasonably assumed. Chiang, in two papers [1,2] formalized the theory of life table analyses in a Markov chain framework and derived maximum likelihood estimates of the relevant parameters for the analyses. He also discussed how the techniques could be generalized to consider competing risks and follow-up studies. Although various computer programs exist for doing different types of life table analysis [3] to date, there has not been a generally available, well documented computer program to carry out multiple decrement analyses, either by Chiang's or any other method. This paper describes such a program developed by Research Triangle Institute. A user's manual is available at printing costs which supplements the contents of this paper with a discussion of the formula used in the program listing.
In 1994, the United States Environmental Protection Agency (USEPA) developed a screening methodology for conducting indirect exposure risk assessments for combustion facilities. The United States Army Center for Health Promotion and Preventive Medicine currently utilizes this methodology in conjunction with other USEPA guidance documents to perform human health risk assessments (HHRAs). The HHRAs require the development of complex human health models using spreadsheet software packages which estimate various media concentrations of contaminants in the environment. Since the quality assurance/quality control procedures associated with verifying the model's results are extremely time consuming, a computer program was developed using Microsoft Excel to minimize the amount of time needed. This discussion describes the 6 steps taken in developing this computer program, which are: (1) understanding the problem; (2) establishing the structure of each table in the spreadsheets; (3) developing an algorithm to solve the problem; (4) writing code; (5) running the program; and (6) testing the results. The automated process of having the computer predict health risk and hazards for each potentially exposed individual saves a tremendous amount of time because each calculated value is placed in the correct spreadsheet cell location. In addition to the time needed to develop human health spreadsheets, this program also minimizes the potential for reducing human error.
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 for the analysis of red cell survival data is described. Experimental data are used to estimate the parameters of seven models of derived from different hypotheses on the red cell destruction process. The program includes statistical tests for the reliability of the estimated parameter values and the bias due to the poor model. A set of criteria for selecting between models is given. The results obtained from simulated and red data are reported and discussed.