Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Programming, Linear”

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 847 records · Page 47Linked to original sources
PubMed2005

A delayed neural network for solving linear projection equations and its analysis.

In this paper, we present a delayed neural network approach to solve linear projection equations. The Lyapunov-Krasovskii theory for functional differential equations and the linear matrix inequality (LMI) approach are employed to analyze the global asymptotic stability and global exponential stability of the delayed neural network. Compared with the existing linear projection neural network, theoretical results and illustrative examples show that the delayed neural network can effectively solve a class of linear projection equations and some quadratic programming problems.

Algorithms↗
PubMed2003

Concept and realization of a multimedia program for veterinary physiology.

A multimedia program, a non-linear system which supplements the traditional, linear way of learning (e.g. with a text book), was developed. Non-linear systems allow the direct use of information in a free sequence. A problem of these systems is the danger that the reader becomes lost in detail. Therefore, a program was constructed which tries to combine the properties of linear and non-linear teaching systems. Student groups were continuously involved during all stages of the project. The program is organized in several levels. These are: (1) choice of chapters; (2) table of contents of one chapter; (3) summary; (4) text and (5) pictures, animations, simulations and video sequences. The program can be used in different ways. In the linear mode, the reader selects via action words different levels of the program. The user can read either only on the level of the summaries or on detailed information (text, pictures, simulations and videos). In the non-linear mode the user jumps via menu items or buttons to selected pictures, simulations or a searched term. In this way, more than 3500 screen pages are integrated into a multimedia program for veterinary physiology. The program is written in TOOLBOOK, and can be used on a personal computer with Windows 95 or higher.

Animal Population Groups↗
PubMed1999

Genetic programming as an analytical tool for non-linear dielectric spectroscopy.

By modelling the non-linear effects of membranous enzymes on an applied oscillating electromagnetic field using supervised multivariate analysis methods, Non-Linear Dielectric Spectroscopy (NLDS) has previously been shown to produce quantitative information that is indicative of the metabolic state of various organisms. The use of Genetic Programming (GP) for the multivariate analysis of NLDS data recorded from yeast fermentations is discussed, and GPs are compared with previous results using Partial Least Squares (PLS) and Artificial Neural Nets (NN). GP considerably outperforms these methods, both in terms of the precision of the predictions and their interpretability.

Computational Biology↗
PubMed1985

Computer-aided construction of nucleic acid restriction maps using defined vectors.

A new algorithm is described that will rapidly produce restriction maps of cloned DNA fragments. Information concerning the vector is stored as a data file and used in constructing probable maps. As the program is based upon a permutation analysis it has two primary uses. First, preliminary restriction maps can be created from fragment length data as a starting point for further analysis. Second, existing maps can be confirmed as being highly probable, and other probable maps examined to ensure certain combinations have not been overlooked. Although primarily designed for linear vectors, the program can be used to calculate circular maps.

Algorithms↗
PubMed2007

Diverting multi-problem youth from juvenile justice: investigating the importance of community influence on placement and recidivism.

In the U.S., diversion has increasingly become one of the most utilized alternatives to detention of delinquent youth. Programs providing diversion can vary greatly. Variations in program design make it difficult to evaluate the effectiveness of program outcomes. Utilizing hierarchical linear modeling, this study examines variations in outcome for ten program sites of the New York State MH/JJ Diversion Project. Program and youth predictors were evaluated on two outcomes: out-of- community placement and recidivism. At the individual level, significant mental health and substance abuse problems, age, prior placements, and use of wraparound funds were predictive of youth placements, while significant substance abuse problems were predictive of recidivism. Program variations were found to have a significant impact on youth outcomes. Specifically, sites providing direct (or "in house") care had significantly reduced rates of placement. Study results and implications for future research are discussed.

Adolescent↗
PubMedDate not supplied

Optimization of moist heat sterilization.

The use of different combinations of sterilization time and temperature in a pilot scale autoclave, GEV 612 AR-2 (Getinge Ab, Sweden), in optimizing the sterilization process was studied. All three programs used had the same sterilization efficacy (F0 = 15 minutes) but different sterilization temperatures (116, 121, and 126 degrees C) and total process times (98, 57, and 44 minutes). The heat distribution during the sterilization phase was, in all cases, very uniform, the greatest difference being 0.5 degrees C. Also the F0 values differed only by +/- 0.5 minutes from each other. The F0 value increases linearly with all programs until the beginning of the cooling phase. The main effect of different sterilization temperatures on the cumulative F0 curves is an increase in the slope of the curves with increasing sterilization temperature. First order temperature change constants were determined both for the heating phase and the cooling phase. The numeric values of the rate constants for the heating and the cooling phases were 0.20 +/- 0.03 and 0.046 +/- 0.005 min-1, respectively. It is concluded that the pilot autoclave used in this study controls the sterilization process very accurately. The observed variations between F0 values at different positions in the autoclave chamber are acceptable. On the basis of this study an accurately engineered and controlled autoclave is required in process optimization. It also is possible to use higher sterilization temperatures than usually suggested in pharmacopeias and thus to shorten the process time.

Hot Temperature↗
PubMed1996

Determination of alpha-methyldopa in human plasma by validated high-performance liquid chromatography with fluorescence detection.

A sensitive reversed-phase gradient elution high-performance liquid chromatographic method with fluorescence detection has been developed for the determination of alpha-methyldopa (AMD) in human plasma. Separation of the investigated compound and the 3,4-dihydroxyphenylalanine (DOPA) internal standard was achieved on a Nucleosil 7 C18 column with a 5 mM heptanesulphonic acid sodium salt containing 0.05 M potassium dihydrogenphosphate (pH 3.2)-acetonitrile mobile phase. The composition of the mobile phase was changed according to a linear gradient time program. Detection was performed at 270 nm fluorimetric excitation and 320 nm emission. The compounds were isolated from plasma by Bond-Elut C18 solid-phase extraction. The limit of quantitation was found to be 10 ng/ml plasma. The assay was validated with respect to accuracy, precision and system suitability. All validated parameters were found to be within the 20% required limits. On the basis of the sensitivity, linearity and validation parameters the developed analytical method was found to be suitable for application in a bioequivalency study.

Chromatography, High Pressure Liquid↗
PubMed1992

Concave Ferguson plots of DNA fragments and convex Ferguson plots of bacteriophages: evaluation of molecular and fiber properties, using desktop computers.

A desktop computer program evaluating physical properties of DNA and bacteriophages is presented. The analysis is based on data obtained from capillary and submarine-type agarose electrophoresis. Native molecular/particle properties and properties of the gel (or polymer) medium can be derived from electrophoresis at several gel concentrations. This is done conveniently by a computerized evaluation of the semi-logarithmic plot of mobility vs. gel concentration, designated the Ferguson plot. In application to most proteins, this plot is linear and computer programs exist to evaluate it. However, nonlinear Ferguson plots have assumed great importance in view of the fact that the plots are concave for DNA. Similarly, convex plots are important since they prevail in the electrophoresis of large particles in agarose. The computer program reported here is the first to (i) address concave Ferguson plots and (ii) allow for the evaluation of both cases using a desktop computer. Program ELPHOFIT version 2.0, a Macintosh application, is available upon request.

Bacteriophages↗
PubMed1996

Pharmacokinetics of acetaminophen sulfate after oral administration in rats: analysis of plasma profiles exhibiting a non-linear second peak.

The pharmacokinetics of the two-peak plasma profiles of orally administered acetaminophen sulfate (APAPS), a major conjugated metabolite of acetaminophen (APAP), in rats was examined by a two-compartment model having two delivery routes with individual time lags: a direct delivery route of APAPS absorbed in an unchanged form and an indirect one where APAPS was absorbed as APAP after deconjugation in the lower intestine. Pharmacokinetic parameters were estimated by a non-linear least squares program, MULTI(FILT), based on the fast inverse Laplace transform algorithm. Plasma APAPS concentration profiles after oral doses were simulated satisfactorily. In a dose escalation study, the peroral availability of APAPS derived from the direct route was not changed significantly with the doses. However, that from the indirect route was decreased with the dose escalation, suggesting the contribution of a capacity-limited deconjugation of APAPS to APAP by the intestinal microflora to the non-linear pharmacokinetics of orally administered APAPS. The absorption of peroral APAPS in rats at a dose range of 30 to 120 mg APAP eq/kg could be summarized as follows: (1) approximately 25% (22 to 32%) of orally administered APAPS are absorbed from the gastrointestinal tract in an unchanged form; (2) more than 50% (50 to 98%) are deconjugated to APAP in the lower intestinal tract; and (3) the latter plays a significant role as an indirect and non-linear APAPS delivery system because considerable amounts of APAP thus absorbed are rapidly reconjugated to APAPS in the systemic circulation, which gives the second plasma APAPS peak.

Acetaminophen↗
PubMed1994

Measuring the fidelity of implementation of a mental health program model.

A fidelity index of program implementation for assertive community treatment (ACT) was developed. In Study 1, 20 experts rated the importance of 73 elements proposed as critical ACT ingredients, also indicating ideal model specifications for elements. Agreement among experts on ratings of importance was high (intraclass r = .98). In Study 2, a 17-item subset of the expert-identified critical ingredients was used to construct a fidelity index with three subscales: Staffing, Organization, and Service. Internal consistencies ranged from .50 to .72, with a .81 reliability for the total scale. Fidelity was linearly related to program "generations," suggesting "program drift." In 18 ACT programs, fidelity also was associated with measures of reduction in days in psychiatric hospitals. The correlation was significant for the total scale and for the Organization and Staffing subscales but not for the Service subscale.

Community Mental Health Services↗
PubMed1995

General purpose model and a computer program for combined segregation and path analysis (SEGPATH): automatically creating computer programs from symbolic language model specifications.

A general purpose model and a flexible computer program, called SEGPATH, have been developed to assist in the creation and implementation of a variety of genetic epidemiological models. SEGPATH is a computer program which can be used to generate programs to implement linear models for pedigree data, based upon a flexible, model-specification syntax. SEGPATH models can perform segregation analysis, path analysis, or combined segregation and path analysis using any user-specified path model and can be structured to analyze any number of multivariate phenotypes, environmental indices, and/or measured covariate fixed effects (including measured genotypes). Population heterogeneity models, repeated-measures models, longitudinal models, auto-regressive models, developmental models, and gene-by-environment interaction models can all be created under SEGPATH. Pedigree structures can be defined to be arbitrarily complex, and the data analyzed with programs generated by SEGPATH can have any missing value structure, with entire individuals missing, or missing on one or more measurements. Corrections for ascertainment can be done on a vector of phenotypes and/or other measures. Because the model specification syntax is general, SEGPATH can also be used in non-genetic applications where there is a hierarchical structure, such as longitudinal, repeated-measures, time series, or nested models. A variety of applications are demonstrated.

Genetics, Population↗
PubMed1996

ABPM-FIT and CV-SORT: an easy-to-use software package for detailed analysis of data from ambulatory blood pressure monitoring.

We describe a non-profit software package for the computerized analysis of ambulatory blood pressure monitoring (ABPM) recordings, in order to make it available to researchers in cardiovascular physiology, pharmacology and medicine. The first program, ABPM-FIT, can load data from several ABPM devices directly as they are stored on disk, making complicated data conversion steps unnecessary. The program performs conventional linear analyses of ABPM data automatically by calculation of mean, SD, load (the percentage of data above a chosen limit), and highest and lowest readings in user-defisned day and night periods. In addition, the area under the parameter-time curve (AUC) and the weighted mean (AUC/time) is calculated for all parameters monitored. In a second step, ABPM-FIT performs a rhythm analysis by fitting partial Fourier series to the data. Only those hormonics are included which significantly reduce the residual variance of the fit. The parameters of these functions (mesor, amplitudes, acrophases), values derived from the composed curves (maximum and minimum, AUC) and their slopes (e.g. maximal increase and decrease) are calculated automatically and, if desired, saved on disk. The second program, CV-SORT, loads groups of result files saved by ABPM-FIT, allows the extraction of parameters of interest for further analyses and creates spreadsheets containing the selected values from groups of patients. In addition, CV-SORT performs simple statistics, and calculates group mean circadian blood pressure and heart rate profiles from individual Fourier curves, with SD, confidence intervals or percentiles. The features of both programs are shown in exemplary analyses of ABPM recordings.

Journal Article↗
PubMed2006

Label-free protein quantification using LC-coupled ion trap or FT mass spectrometry: Reproducibility, linearity, and application with complex proteomes.

A critical step in protein biomarker discovery is the ability to contrast proteomes, a process referred generally as quantitative proteomics. While stable-isotope labeling (e.g., ICAT, 18O- or 15N-labeling, or AQUA) remains the core technology used in mass spectrometry-based proteomic quantification, increasing efforts have been directed to the label-free approach that relies on direct comparison of peptide peak areas between LC-MS runs. This latter approach is attractive to investigators for its simplicity as well as cost effectiveness. In the present study, the reproducibility and linearity of using a label-free approach to highly complex proteomes were evaluated. Various amounts of proteins from different proteomes were subjected to repeated LC-MS analyses using an ion trap or Fourier transform mass spectrometer. Highly reproducible data were obtained between replicated runs, as evidenced by nearly ideal Pearson's correlation coefficients (for ion's peak areas or retention time) and average peak area ratios. In general, more than 50% and nearly 90% of the peptide ion ratios deviated less than 10% and 20%, respectively, from the average in duplicate runs. In addition, the multiplicity ratios of the amounts of proteins used correlated nicely with the observed averaged ratios of peak areas calculated from detected peptides. Furthermore, the removal of abundant proteins from the samples led to an improvement in reproducibility and linearity. A computer program has been written to automate the processing of data sets from experiments with groups of multiple samples for statistical analysis. Algorithms for outlier-resistant mean estimation and for adjusting statistical significance threshold in multiplicity of testing were incorporated to minimize the rate of false positives. The program was applied to quantify changes in proteomes of parental and p53-deficient HCT-116 human cells and found to yield reproducible results. Overall, this study demonstrates an alternative approach that allows global quantification of differentially expressed proteins in complex proteomes. The utility of this method to biomarker discovery is likely to synergize with future improvements in the detecting sensitivity of mass spectrometers.

Amino Acid Sequence↗
PubMed1993

Modeling the behavior and attributes of injecting drug users: a new approach to identifying HIV risk practices.

The behaviors and attributes of 503 Scottish injecting drug users were modeled using the linear structural equations program LISREL. Drug use was directly related to prison experience, sexual activity, sharing of injecting equipment, and prostitution. Although the prevalence of HIV among the sample was low (2.0%), the pattern of risk behaviors observed in the data affords potential for future spread of the virus. Harm reduction measures taken by injectors in response to the threat posed by AIDS were inversely related to drug use but, more encouragingly, directly related to awareness of the disease, treatment for drug use, and prostitution.

Awareness↗
PubMed1990

Non-linear least squares analysis of phase diagrams for non-ideal binary mixtures of phospholipids.

A computer program for non-linear least squares minimization has been applied to construct temperature-composition phase diagrams for several binary systems of different phospholipids based on their calorimetric data. The calculated phase diagram is guided to fit the calorimetric data with two adjustable parameters that describe the non-ideal mixing of lipid components in the gel and liquid-crystalline phases. The parameter estimation procedure is presented to show that the computer program can be used not only to generate phase diagrams with characteristic shapes but also to numerically estimate the lipid-lipid pair interactions between the mixed and the like pairs in the two-dimensional plane of the bilayer in both the gel and liquid-crystalline states. The binary lipid systems examined include dimyristoylphosphatidylcholine/1-palmitoyl-2-stearoylphosphatidylchol ine, 1-capryl-2-behenoylphosphatidylcholine/1-behenoyl-2-lauro ylphosphatidylcholine, and 1-stearoyl-2-caprylphosphatidylcholine/dimyristoylphosphatidylchol ine.

Chemical Phenomena↗
PubMed2000

The influence of a workshop on dental students' perceptions about sexual harassment.

The objective of this study was to determine the effects of a workshop on the sexual harassment perceptions of students at the University of Kentucky College of Dentistry. Responses to a twenty-six-item questionnaire were elicited from 147 first-through fourth-year students before and after they attended a two-hour sexual harassment workshop. Five questions explored students' personal experiences with sexual harassment; twenty-one questions addressed students' attitudes about sexual harassment. The repeated measures option of the SPSS General Linear Model statistical program was used to individually analyze the Likert-type scale response to the twenty-one attitude items for the following variables: gender, year in dental education, and whether respondents had been sexually harassed or had observed harassment of others. Workshop participation significantly changed some student attitudes about sexual harassment regardless of gender, year in dental education, or whether they had been harassed personally or had witnessed harassment of someone else (p < .05). There were also significant gender-related differences in the direction and magnitude of change in pre- versus post-workshop responses to several attitude items (p < .05). Workshop participants were better informed about and more sensitive to a wide range of sexual harassment issues. The workshop empowered students, especially females, to help create an environment that minimizes the probability of sexual harassment. This may be possible because, after the workshop, participants better understood institutional policies and procedures to handle complaints, including provisions for protection from retaliation if they do file a grievance. This knowledge and sensitivity may result in an environment that facilitates the education of beginning general practitioners who are competent, empathetic, and sensitive.

Attitude of Health Personnel↗
PubMed1982

A brief clinical neuropsychologic screening battery: statistical classification trials.

Classified independently 150 neuropsychiatric referrals into Definite (DBD), Suspected (SBD) or No Brain Damage (NBD) groups on the basis of nonneuropsychological evaluative data. Each S was examined with a brief, 2-hour neuropsychologic screening battery, and the test data were analyzed by a stepwise linear discriminant function program. Statistical classifications were compared with criteria for NBD vs. SBD + DBD and for SBD vs. DBD groupings. Hit rates ranged from 95% for the former to 81.7% for the latter, with the low false positives and negatives. Hit and miss rates were not as strong in a validation step, but exceeded chance levels.

Adolescent↗
PubMed2004

The relationship between breast density and bone mineral density in postmenopausal women.

BACKGROUND: It is not well understood whether breast density is a marker of cumulative exposure to estrogen or a marker of recent exposure to estrogen. The authors examined the relationship between bone mineral density (BMD; a marker of lifetime estrogen exposure) and breast density. METHODS: The authors conducted a cross-sectional analysis among 1800 postmenopausal women > or = 54 years. BMD data were taken from two population-based studies conducted in 1992-1993 (n = 1055) and in 1998-1999 (n = 753). The authors linked BMD data with breast density information collected as part of a mammography screening program. They used linear regression to evaluate the density relationship, adjusted for age, hormone therapy use, body mass index (BMI), and reproductive covariates. RESULTS: There was a small but significant negative association between BMD and breast density. The negative correlation between density measures was not explained by hormone therapy or age, and BMI was the only covariate that notably influenced the relationship. Stratification by BMI only revealed the negative correlation between bone and breast densities in women with normal BMI. There was no relationship in overweight or obese women. The same relationship was seen for all women who had never used hormone therapy, but it was not significant once stratified by BMI. CONCLUSIONS: BMD and breast density were not positively associated although both are independently associated with estrogen exposure. It is likely that unique organ responses obscure the relationship between the two as indicators of cumulative estrogen exposure.

Aged↗