A computer program is proposed for the decomposition of spectra into their constituent Gaussian peaks. A new feature of this program is the possibility of operating on different spectra from two or more components of ...
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A computer program is proposed for the decomposition of spectra into their constituent Gaussian peaks. A new feature of this program is the possibility of operating on different spectra from two or more components of variable concentration at the same time, by optimising the wavelengths of the maxima and the halfbandwidths of all the spectra while the height of each peak is optimized in each single spectrum. This distinct treatment is possible due to the fact that the Gaussian functions are linear with respect to the heights and non-linear with respect to the remaining parameters. A linear and non-linear least-squares analysis, respectively, is therefore possible. Besides its intrinsic utility in handling spectral data of different origin this procedure proves more useful than the single spectrum decomposition both in increasing the reliability of the parameters and in improving the convergence properties of the procedure.
In order to analyse the effects of various physiological parameters including blood gas data on the cerebral oxygenation, we developed a model to enable us to estimate PtO2 (tissue PO2) from these physiological parame...
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In order to analyse the effects of various physiological parameters including blood gas data on the cerebral oxygenation, we developed a model to enable us to estimate PtO2 (tissue PO2) from these physiological parameters. This model was applied successfully to a set of blood gas data of a patient who had brain damage after cardiac surgery. Contrary to the original impression, we concluded that a very low PaCO2 of 13 mmHg towards the end of CPB was the most likely cause of his damage.
Purpose. The microcomputer program, MicroPharm-K (MP-K) was developed for pharmacokinetic modeling, including analysis of experimental data and estimation of relevant parameters, and simulation. The intention was to p...
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Purpose. The microcomputer program, MicroPharm-K (MP-K) was developed for pharmacokinetic modeling, including analysis of experimental data and estimation of relevant parameters, and simulation. The intention was to provide a user-friendly, interactive, event-driven program for PC computers. Methods. The data are ascribed to a predefined model from a library including various routes of administration, oral or intra-venous, bolus or infusion, and various compartmental interpretations, 1 to 3. Single and multiple administrations are supported. The program provides initial estimates of the parameters in most cases, and the parameters are then fitted to the model by non linear model fitting using either the Simplex, Evol, Gauss-Newton, Levenberg-Marquardt or Fletcher-Powell algorithms. The nan linear model fitting is based on the maximum likelihood method, and the criterion to minimize is either the weighted least squares (Chi(2) criterion) or the extended least squares. Graphical representations of non-fitted or curve-fitted data are immediately available (including log-scale representation), as well as pharmacokinetic typical parameters such as area under the curve, clearance, volumes, time-rate constants, transfer rate constants, etc. Results. Simulated and experimental data were analysed and the results were similar to those obtained by other programs. Conclusions. This non linear fitting program has been proved in our laboratory to be a very effective package for pharmacokinetic studies, including estimation and simulation. Because it is easy-to-use and runs on basic computers, the program could also be used for educational purposes.
Results are described from application of a computer program that compares the expected and actual incidence of CpG dinucleotides in relation to the codon reading frame of genes, assuming a conserved amino acid sequen...
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Results are described from application of a computer program that compares the expected and actual incidence of CpG dinucleotides in relation to the codon reading frame of genes, assuming a conserved amino acid sequence and normalizing for the third-position incidences of C and G in the remainder of the sequence. Sequences encoding certain proteins showed a pronounced bias in favour of CpG in the {3,1} compared with the {2,3} codon position;whereas sequences encoding related proteins expressed to a similar extent or in the same tissue did not. We propose that the cases exhibiting this bias reflect a difference between the two strands of the DNA duplex in their susceptibility to loss of CpG dinucleotides by mutation. Although in vertebrates this loss of CpG dinucleotides from the sense strand might reflect strand-asymmetry in deamination of 5-methylcytosine residues, the fact that a similar CpG codon bias is found in some invertebrates indicates that other factor(s) must also be involved.
The bacterial lad gene has been used for many years as a mutational target for the study of the mechanisms of mutation. A wealth of information has been collected for many mutagenic treatments and in strains with dive...
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The bacterial lad gene has been used for many years as a mutational target for the study of the mechanisms of mutation. A wealth of information has been collected for many mutagenic treatments and in strains with diverse DNA repair backgrounds. Recently this gene has been used in the construction of a transgenic mouse, named Big Blue(R), and a transgenic rat, as well as a rot cell line. The loci gene in these animals and cells can conveniently be recovered and analyzed in bacteria. This makes it possible to study mutagenic potential of chemical compounds in vivo using a mammal. Tissue, strain, and gender specificity can be addressed. In addition, mutations recovered from tumour tissues or from animals with specific genetic backgrounds can be analyzed conveniently. The mammalian systems can produce large numbers of mutants that require computer assistance to manage the samples and the resulting DNA sequence date. Accordingly, a computer software system was developed. The system maintains an inventory of bacteriophage lambda lad mutants and allows entry of mutant sequences while performing accuracy checks on the data. The software features several options for displaying lists of mutants. The system can perform several analyses, including mutant class compilations, mutational spectra comparisons, and clonal expansions analysis. An extensive database obtained from the bacterial loci system is included with the software and can be analyzed along with mutants derived from transgenic animals. (C) 1995 Wiley-Liss, Inc.
Selectivity analyses generally aim to quantify model result changes with respect to input changes. This study instead forces on the site- and condition-specific nature of sensitivity, to demonstrate why users benefit ...
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Selectivity analyses generally aim to quantify model result changes with respect to input changes. This study instead forces on the site- and condition-specific nature of sensitivity, to demonstrate why users benefit by conducting their own sensitivity analyses as an essential step in model applications. This is demonstrated by employing the RUSLE model, which predicts average annual soil loss within a field. Sensitivity by computed soil loss to changes in selected parameters and variables is quantified under a range of sites and conditions. Input parameters representative of several common forms are varied about base values for the variety of scenarios. The scenarios include a corn/soybean rotation near Chicago, Illinois, the same scenario moved to the Atlanta, Georgia, area, and a corn/soybean/winter wheat rotation near Topeka, Kansas. Both conventional and no-till management schemes are tested at the three locations. Results show that model sensitivity may vary both with site and with management conditions being simulated These results serve to caution users of complex computer models not to rely upon sensitivity results that were conducted under conditions other than those being simulated. A serendipitous result is the demonstration of how the form of presenting results affects user perspective of the importance of those results.
The importance of computer science as a working tool for the health sector is an unquestionable fact in any modern society. EPIDEMO, developed by the authors, can be defined as a set of programs whose main characteris...
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A resident powder diffractometer control program is described, which allows independent use of the PC for other programs during data collection. The control program and a simple interface card were developed for the c...
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The new German standard specification DIN 32645 defines detection, identification and determination limit of analytical experiments and contains formulas for their calculation. The detection limit is a qualitative val...
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The new German standard specification DIN 32645 defines detection, identification and determination limit of analytical experiments and contains formulas for their calculation. The detection limit is a qualitative value, only at the determination limit a quantitative statement is possible. The identification limit is no limit of decision for analyses. The expenditure for calculating these parameters is considerable. Therefore, a computer program was developed and tested at the analysis of herbicides with GC-MS after enrichment with solid phase extraction (SPE). It proved that the program is also very useful at the development of analytical methods, because it allows a quick examination of changes of the analytical method. After optimization detection limits for the herbicides were achieved which amount 10-20% of the limit of the German drinking water regulation.
El objetivo de este artículo es describir un programa informático realizado con el propósito de facilitar el aprendizaje del código dactilológico. Este programa debe entenderse en el contexto ...
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El objetivo de este artículo es describir un programa informático realizado con el propósito de facilitar el aprendizaje del código dactilológico. Este programa debe entenderse en el contexto más general de proporcionar ayudas técnicas a las personas discapacitadas, así como a aquellas que se relacionan con ellas de manera directa, bien sea en contextos escolares, familiares o ***, en primer lugar, una breve referencia al código dactilológico y su lugar en la comunicación entre personas con discapacidad auditiva, y en segundo lugar, una presentación del programa informá*** este artículo se expone los principios de un programa informático denominado DITS que se ha realizado para aprender dactilología. El programa utiliza un tipo de letra, diseñado especialmente, que reproduce los signos manuales equivalentes al alfabeto, castellano y catalán. DITS consta de distintos módulos, de dificultad creciente, así como de un editor de listas de palabras que permite incorporar nuevas a las secuencias de aprendizaje.
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