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At least 325 records · Page 18Linked to original sources

A program for sampling, assessment of stationarity and variability analysis of neuronal spike trains, run under control of a time-sharing system.

A system has been developed for off-line analysis of discharge characteristics of continuously firing nerve cells. The programs, which are mainly written in FORTRAN IV, determine mean firing rates, variability and other parameters of the impulse activity, and construct interspike interval histograms. They are run under time-sharing on a small laboratory computer. To disclose possible non-stationarities in the data all interspike interval samples are analysed with the non-parametric Kolmogorov-Smirnov test. This test is very powerful in detecting any differences between two samples and is still very easy to implement in programming. Raw data and computed statistics are stored in random access data files.

Computers↗

An analysis of variance program for the evaluation of results of parallel line assays.

A program is described and illustrated for the one-way analysis of variance of parallel line assays. The procedure involves 4 distinct steps: Data input, either from a previously-prepared data file or by direct 'manual' progression with options to correct input errors; data display, in tabular form, of the results from each specimen after several available transformation options; displays of the analysis of variance table, potency ratio, and confidence limits on the basis of results selected from the data display mode; and, a standard, commercially-available plotting capability of either actual or idealized regression lines. The program provides a rapid, convenient, and accurate procedure, with a high level of operator interaction, with which to perform the somewhat cumbersome mathematical manipulations necessary for the evaluation of parallel line assay results. The availability of this program should overcome one of the problems which frequently prevents the complete analysis and validation of the results of parallel line assays.

Analysis of Variance↗

Application of diode array detection for the identification of poisoning by traditional medicines.

A large percentage of acute poisonings in black South Africans is due to traditional medicines and plants. The combination of isocratic high performance liquid chromatography (HPLC) with on line UV spectrum detection via a diode array configuration has been applied to the detection and identification of traditional medicines (and plants) in poisoned patients. Four standard isocratic systems are used. Combination of the retention times in the HPLC chromatogram and a comparison of the full spectra between 190-600 nm of the peaks obtained from extracted patient samples (urine or blood) with that of traditional medicine extracts (collected and stored in a reference data file) makes reliable identification possible. Such information could improve the quality of data accumulation and therapeutic strategies.

Chromatography, High Pressure Liquid↗

The analysis of soil cores polluted with certain metals using the Box-Cox transformation.

To define the soil properties for a given area or country including the level of pollution, soil survey and inventory programs are essential tools. Soil data transformations enable the expression of the original data on a new scale, more suitable for data analysis. In the computer-aided interactive analysis of large data files of soil characteristics containing outliers, the diagnostic plots of the exploratory data analysis (EDA) often find that the sample distribution is systematically skewed or reject sample homogeneity. Under such circumstances the original data should be transformed. The Box-Cox transformation improves sample symmetry and stabilizes spread. The logarithmic plot of a profile likelihood function enables the optimum transformation parameter to be found. Here, a proposed procedure for data transformation in univariate data analysis is illustrated on a determination of cadmium content in the plough zone of agricultural soils. A typical soil pollution survey concerns the determination of the elements Be (16 544 values available), Cd (40 317 values), Co (22 176 values), Cr (40 318 values), Hg (32 344 values), Ni (34 989 values), Pb (40 344 values), V (20 373 values) and Zn (36 123 values) in large samples.

Agriculture↗

STEREO: a program on a PC-Windows 95 platform for recording and evaluating quantitative stereologic investigations of multistage hepatocarcinogenesis in rodents.

The most common organ site of neoplasms induced by carcinogenic chemicals in the rodent bioassay is the liver. The development of cancer in rodent liver is a multistage process involving sequentially the stages of initiation, promotion, and progression. During the stages of promotion and progression, numerous lesions termed altered hepatic foci (AHF) develop. STEREO was developed for the purpose of efficient and accurate quantitation of AHF and related lesions in experimental and test rodents. The system utilized is equipped with a microcomputer (IBM-compatible PC running Windows 95) and a Summagraphics MICROGRID or SummaSketch tablet digitizer. The program records information from digitization of single or serial sections obtained randomly from rat liver tissue. With this information and the methods of quantitative stereology, both the number and volume percentage fraction of AHF in liver are calculated in three dimensions. The recorded data files can be printed graphically or in the format of tabular numerical data. The results of stereologic calculations are stored on floppy disks and can be sorted into different categories and analyzed or displayed with the use of statistics and graphic functions built into the overall program. Results may also be exported into Microsoft Excel for use at a later time. Any IBM-compatible PC capable of utilizing Windows 95 and MS Office can be used with STEREO, which offers inexpensive, easily operated software to obtain three-dimensional information from sections of two dimensions for the identification and relative potency of initiators, promoters, and progressors, and for the establishment of information potentially useful in developing estimations of risk for human cancer.

Animals↗

Assessing the feasibility of using computerized pharmacy refill data to monitor antidepressant treatment on a population basis: a comparison of automated and self-report data.

This article compares self-report and automated data as measures of dose and duration of antidepressant use in order to assess the feasibility of using automated pharmacy data in a disease management context. We used self-report and computerized refill data to identify two treatment failures-premature discontinuation of the medication and sub-optimal dosages-at time points 1 and 4 months after initiation of antidepressant therapy. The sources showed modest agreement regarding identification of current users at 1 month (kappa = .33); agreement was high at 4 months (kappa = .72). Agreement regarding dosage adequacy was also higher later in treatment, with kappas of .52 and .65 at 1 and 4 months, respectively. The two sources showed high agreement on an overall measure of acute phase treatment adequacy (kappa = .80). Data completeness was another outcome, with data on current users and overall treatment adequacy generally available from computerized files, data on dose less so. Automated pharmacy data appear to be a feasible means of monitoring treatment adequacy and quality of care as part of a disease management approach to improving care for populations of patients.

Antidepressive Agents↗

Practical approach to archival and retrieval of analytical data in the laboratory.

Today's analytical laboratory uses a large number of different instruments that are connected in networks. Together with increasing automation, data are produced at a rate that can easily reach gigabytes per month, which generates the problem of systematic archival. In addition, working under Good Laboratory Practice requires that archival of raw data be performed in such a way that they can be readily retrieved upon request, even years later. While systematic archival of data is already performed in most laboratories, it is the retrieval of saved information that is often far from straightforward. This paper describes a simple but systematic approach for both archival and retrieval of data files and related electronic documents. It consists of an unambiguous scheme for the naming of electronic files, an efficient backup strategy, a simple database holding information about any data acquired, and a convenient interface to this database that can be accessed from any workplace while assuring restricted access. The system is capable of handling several databases concurrently and is used in our facility to archive data from several workgroups. The use of freely available software such as the Linux operating system made it possible to implement a fast and stable solution at exceptionally low cost.

Chemistry Techniques, Analytical↗

AKA-Glucose: a program for kinetic and epidemiological analysis of frequently sampled intravenous glucose tolerance test data using database technology.

BACKGROUND: The Bergman Minimal Model enables estimation of two key indices of glucose/ insulin dynamics: glucose effectiveness and insulin sensitivity. METHODS AND RESULTS: In this paper we describe AKA-Glucose, a program that combines MINMOD Millennium (minimal model analysis software) with relational database technologies. AKA-Glucose enables the fitting of individual frequently sampled intravenous glucose tolerance test (FSIGT) data sets to the Minimal Model and the secure storage in a dedicated database (and retrieval from) of thousands of individual subjects' demographic data, their individual FSIGT data, and each subject's parameters and indices derived from minimal model analysis. AKA-Glucose also enables the population analysis of various strata or subpopulations within the database. AKA-Glucose has all of the capabilities of MINMOD Millennium, provides Minimal Model parameter estimates that are concordant with estimates from previous MINMOD software, and allows importation of data files from earlier versions of the MINMOD software. CONCLUSIONS: By combining FSIGT data fitting, population analysis, and relational database technologies, AKA-Glucose is the first minimal model software designed specifically for researchers confronted with minimal model and epidemiological analysis of large numbers of either human or animal FSIGT data sets.

Adult↗

Development of an integrated laboratory information management system for the maize mapping project.

MOTIVATION: The development of an integrated genetic and physical map for the maize genome involves the generation of an enormous amount of data. Managing this data requires a system to aid in genotype scoring for different types of markers coming from both local and remote users. In addition, researchers need an efficient way to interact with genetic mapping software and with data files from automated DNA sequencing. They also need ways to manage primer data for mapping and sequencing and provide views of the integrated physical and genetic map and views of genetic map comparisons. RESULTS: The MMP-LIMS system has been used successfully in a high-throughput mapping environment. The genotypes from 957 SSR, 1023 RFLP, 189 SNP, and 177 InDel markers have been entered and verified via MMP-LIMS. The system is flexible, and can be easily modified to manage data for other species. The software is freely available. AVAILABILITY: To receive a copy of the iMap or cMap software, please fill out the form on our website. The other MMP-LIMS software is freely available at http://www.maizemap.org/bioinformatics.htm.

Chromosome Mapping↗

Effective electron-density map improvement and structure validation on a Linux multi-CPU web cluster: The TB Structural Genomics Consortium Bias Removal Web Service.

Anticipating a continuing increase in the number of structures solved by molecular replacement in high-throughput crystallography and drug-discovery programs, a user-friendly web service for automated molecular replacement, map improvement, bias removal and real-space correlation structure validation has been implemented. The service is based on an efficient bias-removal protocol, Shake&wARP, and implemented using EPMR and the CCP4 suite of programs, combined with various shell scripts and Fortran90 routines. The service returns improved maps, converted data files and real-space correlation and B-factor plots. User data are uploaded through a web interface and the CPU-intensive iteration cycles are executed on a low-cost Linux multi-CPU cluster using the Condor job-queuing package. Examples of map improvement at various resolutions are provided and include model completion and reconstruction of absent parts, sequence correction, and ligand validation in drug-target structures.

Apolipoproteins E↗

Writing software for the clinic.

Medical physicists often write computer programs to support scientific, educational, and clinical endeavors. Errors in scientific and educational software can waste time and effort by producing meaningless results, but errors in clinical software can contribute to patient injuries. Although the ultimate goal of error-free software is impossible to achieve except in very small programs, there are many good design, implementation, and testing practices that can be used by small development groups to significantly reduce errors, improve quality, and reduce maintenance. The software development process should include four basic steps: specifications, design, implementation, and testing. A specifications document defining what the software is intended to do is valuable for clearly delimiting the scope of the project and providing a benchmark for evaluating the final product. Keep the software design simple and straightforward. Document assumptions, and check them. Emphasize maintainability, portability, and reliability rather than speed. Use layers to isolate the application from hardware and the operating system. Plan for upgrades. Expect the software to be used in unplanned ways. Whenever possible, be generous with RAM and disk storage; hardware is cheaper than development and maintenance. During implementation, use well-known algorithms whenever possible. Use prototypes to try out ideas. Use generic modules, version numbering, unique file names, defensive programming, and operating system and language/compiler defaults. Avoid binary data files and clever tricks. Remember that real numbers are not exact in a computer. Get it right before making it faster. Document the software extensively. Test continuously during development; the later a problem is found, the more it costs to fix. Use a written procedure to test the final product exactly as a typical user would run it. Allow no changes after clinical release. Expect to spend at least an additional 50% of the initial development effort on testing, fixing errors, and getting the software into routine operation.

Documentation↗

Telesurveillance of elderly patients by use of passive infra-red sensors in a 'smart' room.

We have developed an automated surveillance system based on passive infra-red sensors. Eight sensors were installed in a hospital room. A computer automatically captured data from the sensors every night from 21:00 until 06:00 the following morning. The sensors were polled twice per second and when a sensor was activated by movement, the event and time were recorded in a data file. At the end of the surveillance period the program analysed the data and generated a report showing the activities taking place in the room and their times. Four elderly patients were observed for a total of 97 nights. A total of 1637 possible sequences of movements by the patient and the hospital staff were detected. The computer was able to identify 1450 sequences (89%) correctly, in comparison with manual analysis. Only 10 movements (0.6%) were undetected by the system; all were very short sequences (five or six activations of the sensors). The system was generally capable of detecting and classifying all major movements in the room.

Aged↗

Explaining race differences in mortality among the Tennessee Medicare elderly: the role of physician services.

We investigated the impact of socioeconomic conditions, patterns of morbidity, and physician service utilization on race differences in rates of mortality, and mortality associated with specific diagnoses. Longitudinal data from the Center for Medicare and Medicaid Services (CMS) Physician Billing File data and the Medicare Enrollment Database (EDB) were analyzed to assess physician-diagnosed morbidity, health service use, and mortality, among the population of Medicare beneficiaries in Tennessee (N=665,887). Proportional hazards models were used to examine the effects of race, socioeconomic status, morbidity, and physician service utilization on mortality. Race differences in physician visits explain the largest portion of mortality differentials between African Americans and Whites. Race disparities in mortality associated with particular forms of morbidity are also mostly a function of differences in physician service use. Our examination suggested that race differences in patterns of physician service use principally explain race disparities in mortality. Further, race differences in the use of physician services were substantially responsible for race disparities in mortality associated with particular forms of morbidity.

Black or African American↗

Medicare Part B spending.

In its continuing effort to identify and examine the trends in Medicare spending for surgical services, the College obtained copies of the Medicare procedure code files for the years 1986 through 1989. The results from analysis of these data files were presented in a report entitled Trends in Medicare Part B Spending 1986-1989, issued by the College in September 1991. This article describes the federal activity that prompted the College to commission the report, and presents some of the significant results of the analysis.

Data Interpretation, Statistical↗

Gallbladder surgery for Medicare patients in Mississippi.

Mississippi Foundation for Medical Care (MFMC) conducted a review of gallbladder surgery performed on Mississippi Medicare Patients using hospital claims files and limited record review for verification of claims file data. Significant error rates in the surgeon identification number were found in the claims files. It should also be noted that the current ICD-9-CM coding system does not allow for identification of laparoscopic cholecystectomies converted to open procedures. Past studies have attempted to use claims data alone for these types of analyses. These findings demonstrate the importance of using caution by those attempting to use claims data (without verification) to define patterns of hospital utilization, clinical outcomes and/or physician profiling. Claims data must be tested for validity for reliable pattern analysis. In addition, considerable variation was found among providers in elements such as conversion rates, complication and readmission rates. A few surgeons showed patterns for critical variables that were quite different from the universe. There was however, no statistically significant differences associated between volume of cases performed and outcomes. Time frame comparisons over several years show significant (> 80%) increase in gallbladder surgery since the introduction of the laparoscopic procedure.

Cholecystectomy↗

Two level entry concept for analog digital conversion package: usage as blackbox or toolkit.

Analog/Digital conversion of up to 16 channels can be set up and executed interactively with sampling rates individually adjusted for each channel. Additionally, asynchron and parallel digital I/0 is provided, including the possibility of triggering the beginning and the end of data acquisition on an external TTL signal. For non-experienced personnel the package can be run fully interactively with help-menus. Conversely, the experienced user can skip the menu level and directly access the A/D conversion card at the programmers' level in FORTRAN, BASIC or PASCAL. This two level approach considerably enhances the versatility of the package. Data structures in memory and on disk are the same for both levels. Thus, data acquired in menu mode can be compatibly accessed and evaluated from the menu--as well as the programmers' level. Furthermore, a concept is presented for a most efficient and convenient transfer of pre-processed data onto an IBM-mainframe for further analysis in SAS. This transfer scheme allows for continued transparency of the data files, should--for technical reasons or due to changes in the type of data acquired--changes or upgradings of the A/D conversion software become necessary. The package is available for IBM-XT/AT personal computers.

Analog-Digital Conversion↗