Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Mathematical Computing”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed1992

The effects of computer-based attribution retraining on the attributions, persistence, and mathematics computation of students with learning disabilities.

The purpose of the present study was to examine the impact of attribution retraining, embedded within a mathematics computer-assisted instructional (CAI) program, on students' attributions, persistence, and mathematics computation. Twenty-nine school-identified students with learning disabilities from five urban schools participated in the study. The sample's mean age was 13.3 years. After blocking on initial attributional patterns, students were randomly assigned to a mathematics CAI program that provided either attribution retraining or neutral feedback. Students used their assigned program for eight 30-minute sessions. Results did not support the contention that attribution retraining would have a significant impact on students' attributions. However, students who participated in the attribution retraining condition completed significantly more levels of the program than their counterparts who received neutral feedback. Attribution retraining students also obtained significantly higher scores on a test of problems practiced during the CAI program. These results suggest that attribution retraining may be a desirable addition to the type of feedback typically provided by CAI programs. However, they also highlight the need for further research that examines the conditions under which specific attributions are most advantageous.

Achievement↗
PubMed1991

A mathematical computer stimulation model for the development of colonic polyps and colon cancer.

Currently known information about the development and progression of colon polyps and cancer is summarized and organized into a mathematical computer simulation model that successfully predicts the natural history of colon polyp and cancer development for an average patient with (1) familial polyposis coli (2) genetic susceptibility as measured by a positive family history, and (3) negative family history with a high fat diet. The mathematical model uses four distinct types of cells (normal, transformed, polypoid, and cancerous) and two kinetic processes (mutation and promotion). Arachidonic acid metabolites play a role in the model in the promotion of cancer from polyps, and account for that promotion through: (1) their effect on encouraging more polypoid cells in mitosis to move toward cancer; and (2) their immunosuppressive effect over time. The model also shows that one defect in allowing more cells to mutate to the transformed state is sufficient to account for the chain of events leading to the clinical sequelae of familial polyposis coli. A second genetic effect at another point in the process is unnecessary. The mechanism of action of Sulindac on colon polyps is explained by the model through inhibition of production of arachidonic acid metabolites, most notably prostaglandin E.

Adenomatous Polyposis Coli↗
PubMed1991

Cardiac electrophysiological experiments in numero, Part I: Concepts and strategies of mathematical and computer models.

This article is the first of three articles that review mathematical and computer models of the heart and describe their construction, development, research potential, and clinical utility. This article explains the methodological principles of mathematical and computer simulation of biomedical systems. The strategies of model construction, testing, and application are presented; the advantages and limitations of computer simulation studies are explained, and the basic value of computer simulation for cardiological research and practice is discussed.

Cardiac Pacing, Artificial↗
PubMed1977

[Basic trends in the use of mathematics and computer technics in cardiology].

Five cardinal, according to the author, trends in the utilization of mathematics and computing technique in cardiology are discussed, viz. in the diagnosis, including mass-examinations of the population; in prognosing, with screening at the time of mass-examination of the population groups of persons presenting risks as to the development of atherosclerosis, myocardial infarction, hypertensive disease, etc.; in the treatment; in the organization of information-search systems; in modelling. The significance of the cited trends for theoretical and practical cardiology is shown on examples from experience of the work carried out by research bodies headed by the author.

Cardiology↗
PubMed1991

[The use of computers and mathematical methods for optimizing epidemic control measures with respect to measles infection].

The potentialities of computers for the study of the effectiveness of immunization have been demonstrated and the mathematical model for the prediction of the proportion of children, seronegative to measles, derived on the basis of the data on the average measles morbidity in different groups for a given period. A multifactor analysis of a large scope of data obtained in seroepidemiological survey and a retrospective analysis of measles morbidity on the basis of data collected in two districts of Moscow have been carried out with the use of computers and mathematical methods.

Age Factors↗
PubMed2017

Addressing current challenges in cancer immunotherapy with mathematical and computational modelling.

The goal of cancer immunotherapy is to boost a patient's immune response to a tumour. Yet, the design of an effective immunotherapy is complicated by various factors, including a potentially immunosuppressive tumour microenvironment, immune-modulating effects of conventional treatments and therapy-related toxicities. These complexities can be incorporated into mathematical and computational models of cancer immunotherapy that can then be used to aid in rational therapy design. In this review, we survey modelling approaches under the umbrella of the major challenges facing immunotherapy development, which encompass tumour classification, optimal treatment scheduling and combination therapy design. Although overlapping, each challenge has presented unique opportunities for modellers to make contributions using analytical and numerical analysis of model outcomes, as well as optimization algorithms. We discuss several examples of models that have grown in complexity as more biological information has become available, showcasing how model development is a dynamic process interlinked with the rapid advances in tumour-immune biology. We conclude the review with recommendations for modellers both with respect to methodology and biological direction that might help keep modellers at the forefront of cancer immunotherapy development.

Computer Simulation↗
PubMedDate not supplied

Computational analysis and dosimetric evaluation of a commercial irregular-fields computer program.

The proper evaluation of the accuracy of a new computer program for radiation-therapy dosimetry requires consideration of both the mathematical algorithm used in the program and the performance required in clinical applications. As an example, our evaluation of the irregular-fields dosimetry program currently marketed by SHM for their Rad-8 system is described. The evaluation begins with an explanation of the mathematical computation described. The evaluation begins with an explanation of the mathematical computation method, with emphasis on the points where the calculation differs from previous methods. Next, the procedure for setting up the beam data file is discussed. Finally, a step-by-step procedure is described in which calculated doses are compared with measured doses, using a Varian Clinac-4 with lead flattening filter, and the limits within which a +/- 5% accuracy is attainable are estimated. Some sources of error and areas for possible improvements are mentioned.

Computers↗
PubMed1976

[Use of computers and mathematical methods in epidemiological work. V. Assessment of infection morbidity using standardized indices].

The paper treats of the method of obtaining special and generalized indices on the computer M-222 to be used for the analysis of infectious morbidity under the automatic control system conditions. Assessment of significance of the differences between the actual number of diseases and the "usual" morbidity level characteristic of the given territory and the time of the year lies at the basis of the calculation of the standardized indices. Complex evaluation of the epidemiological condition of the controlled district was carried out according to the data of the official monthly and annual sanitary-epidemiological report forms No. 85.

Computers↗
PubMed1976

Changes in the shape of the developing vertebrate nervous system analyzed experimentally, mathematically and by computer simulation.

Two forces are necessary and sufficient to produce the transformation of the newt neural plate from a hemispheric sheet of cells one cell thick to a keyhole shape. These forces are: (1) a regionally programmed shrinkage of the surface of the neural plate (accomplished by contraction of the apical surfaces of the neural plate cells and elongation of these cells perpendicular to the plate); and (2) displacement of the whole sheet caused by elongation of either the notochord or the overlying neural plate cells in the antero-posterior direction. A computer simulation and mathematical analysis ("morphodynamics"), together with experiments and observations on embryos, were used to deduce the morphogenesis of the neural plate from these forces.

Animals↗
PubMed1976

[Use of a computer and mathematical methods in epidemiological work. Report 3. Experience with the operational tracing of infectious morbidity using an automic self-service information unit].

The authors describe their experience in the elaboration and introduction into practice of epidemiological service of the system of operative tracing of infectious morbidity at the level of the central sanitary-epidemiological station under conditions of automatic control system. Data on improvement of information supply and logic analysis of the information with the aid of Minsk-22 computer are presented. Forms of documents are considered. Experience in the use of this system for two years pointed to its expediency.

Communicable Diseases↗
PubMed1976

Screening random asymptomatic women under 50 by annual mammographies: does it make sense?

The effectiveness of screening random asymptomatic women for breast cancer using mammography has been analyzed using a new mathematical-computer technology. The technology is based on a general mathematical theory of screening recently developed by Blumenson combined with a mathematical model for breast cancer developed by Blumenson and Bross over the past decade. The technology makes it relatively simple to try alternative strategies for age at onset of screening, screening interval, etc. and to calculate the relative effectiveness of the strategy. When the benefits of alternative strategies with periodic screening beginning at different ages were compared with the increasing risk of iatrogenic disease from multiple exposure to low levels of radiation, it was concluded that screening of asymptomatic women should begin no earlier than age 50.

Age Factors↗
PubMed1991

A deterministic computer simulation model of life-cycle lamb and wool production.

A deterministic mathematical computer model was developed to simulate effects on life-cycle efficiency of lamb and wool production from genetic improvement of performance traits under alternative management systems. Genetic input parameters can be varied for age at puberty, length of anestrus, fertility, precocity of fertility, number born, milk yield, mortality, growth rate, body fat, and wool growth. Management options include mating systems, lambing intervals, feeding levels, creep feeding, weaning age, marketing age or weight, and culling policy. Simulated growth of animals is linear from birth to inflection point, then slows asymptotically to specified mature empty BW and fat content when nutrition is not limiting. The ME intake requirement to maintain normal condition is calculated daily or weekly for maintenance, protein and fat deposition, wool growth, gestation, and lactation. Simulated feed intake is the minimum of availability, DM physical limit, or ME physiological limit. Tissue catabolism occurs when intake is below the requirement for essential functions. Mortality increases when BW is depressed. Equations developed for calculations of biological functions were validated with published and unpublished experimental data. Lifetime totals are accumulated for TDN, DM, and protein intake and for market lamb equivalent output values of empty body or carcass lean and wool from both lambs and ewes. These measures of efficiency for combinations of genetic, management, and marketing variables can provide the relative economic weighting of traits needed to derive optimal criteria for genetic selection among and within breeds under defined industry production systems.

Animals↗
PubMed1990

A computer designed graph for administration of atracurium by i.v. infusion.

A bi-exponential mathematical computer model was used to develop a guidance graph for atracurium infusions. The model permitted variation in infusion rates, in pharmacokinetic parameters and in "effect" thresholds. Systematic experiments revealed a relationship between the rate of recovery from a fixed bolus loading dose and the most appropriate initial infusion rate. This relationship was expressed as a guidance graph or "ready reckoner". The quality of guidance was assessed in 50 anaesthetics, given consecutively. In 39 patients optimal myoneural block for surgery was maintained for the duration of the infusion without adjustments or supplementary bolus doses. The mean operating time was 92 min and the mean duration of infusion was 59 min.

Adult↗
PubMed1991

[Automated diagnosis of vibration disease].

Based on a multidimensional discriminant analysis of the clinical and physiological characteristics derived as a result of examination of 593 miners, classification functions were plotted, allowing the diagnosis of vibratory disease in the automatic mode by means of mathematic computations. Functional indicators of skin sensitivity, particularly vibratory, dynamometry, rheovasography and thermography of the hand and fingers, a "white spot" symptom, and characteristics derived on a mathematic analysis of heart rhythm were established to be informative for automated diagnosis. The diagnosis was found to be more accurate in case of using a two-stage variant of the discriminant analysis where the differentiation is first made between healthy workers and workers with a pathology, followed by the discrimination of the preclinical and clinical phase of the disease. The automated diagnostic system is demonstrated to compare very favourably with the conventional method of diagnosis.

Arctic Regions↗
PubMed1991

Modeling and simulation in biomedicine.

A group of researchers and educators in The Netherlands, Germany and Czechoslovakia have developed and adapted mathematical computer models of phenomena in the field of physiology and biomedicine for use in higher education. The models are graphical and highly interactive, and are all written in TurboPascal or the mathematical simulation language PSI. An educational shell has been developed to launch the models. The shell allows students to interact with the models and teachers to edit the models, to add new models and to monitor the achievements of the students. The models and the shell have been implemented on a MS-DOS personal computer. This paper describes the features of the modeling package and presents the modeling and simulation of the heart muscle as an example.

Computer Graphics↗