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 1,063 records · Page 59Linked to original sources

Binding of [3H]mianserin to bovine serum albumin, human serum albumin and alpha 1-acid glycoprotein.

Scatchard plots which were curvilinear with negative slopes were obtained when the binding of [3H]mianserin to bovine serum albumin (BSA), human serum albumin (HSA), defatted human serum albumin (D-HSA) and alpha 1-acid glycoprotein (alpha 1-AGP) was studied with equilibrium dialysis with constant protein concentrations and various ligand concentrations. Binding parameters were estimated graphically and with a non-linear least-squares computer program, assuming two classes of independent binding sites. alpha 1-AGP had the highest binding affinity (K) and binding capacity (nK). The binding parameters, n and K were not independent of protein concentration when the BSA concentration was varied. Linear atypical Scatchard plots with positive slopes were obtained when the protein concentration was varied for BSA, HSA and D-HSA, at a fixed ligand concentration.

Animals↗

Relationship between case manager contact and outcome for frequently hospitalized psychiatric clients.

OBJECTIVE: Case management services and client outcomes in seven programs based on the assertive community treatment model were examined to determine variability in the frequency and location of services, to determine the relationship of frequency of services with reduction in hospital use and with client satisfaction with services, and to identify subgroups of clients who received different patterns of services. METHODS: Correlational and cluster analyses were used to examine patterns of service use for 155 clients with serious mental illness who averaged 10.6 lifetime psychiatric hospitalizations. Data were drawn from four earlier studies of the treatment model. RESULTS: The programs varied substantially in the mean frequency of service provided. Contrary to expectations, service intensity was not linearly related to client outcomes. However, programs that delivered very low frequencies of service were ineffective in reducing hospital use. Finally, cluster analysis of service variables identified five client subgroups. These subgroups differed on demographic characteristics and mental health history but not on outcomes. CONCLUSIONS: A minimum intensity of services, individualized for each client, may be necessary to reduce hospital use for frequently hospitalized clients. Service utilization clusters may represent clients with different service needs and preferences.

Adult↗

Quality of life and symptom severity for individuals with chronic fatigue syndrome: findings from a randomized clinical trial.

OBJECTIVE: Chronic fatigue syndrome is a profoundly disabling condition characterized by severe, unrelenting fatigue and a number of other physical and cognitive symptoms. Currently, there is no cure or widely accepted treatment for chronic fatigue syndrome, and few rehabilitation programs exist to address quality of life issues in chronic fatigue syndrome. In the present randomized clinical trial, the effects of an integrative, consumer-driven rehabilitation program on quality of life and symptom severity for individuals with chronic fatigue syndrome were examined. METHOD: Forty-seven participants were randomly assigned to either an immediate program group (n = 23) or a delayed program control group (n = 24) and assessed with the Chronic Fatigue Syndrome Symptom Rating Scale and the Quality of Life Index before the program, after program participants completed the group phase, and after program participants completed the one-on-one phase. It was hypothesized that the program would lead to improvements in quality of life and an overall reduction in symptom severity. RESULTS: Linear growth models were estimated comparing program and control conditions over time using random-effects regression analyses. Significant condition by time interactions were observed for the main outcomes of symptom severity and overall quality of life. Effect sizes for these interactions involving symptom severity (Cohen's d = 0.71) and overall quality of life (Cohen's d = .66) were moderate. CONCLUSIONS: Findings indicate that consumer driven programs such as this one can have a positive impact on symptom severity and quality of life over time for individuals with chronic fatigue syndrome.

Fatigue Syndrome, Chronic↗

Reference values for second trimester fetal and neonatal organ weights and measurements.

To establish accurate reference ranges for the entire second trimester, we documented organ weights, body weight, and linear measurements for 597 fetuses and neonates with gestational ages ranging from 12 to 26 wk. We determined the mean and standard deviation for weights and measurements at each week of gestation using the StatView trade mark SE + Graphics statistical program. The analyses revealed a linear correlation between the gestational age and, respectively, the toe-heel length, crown-rump length, and crown-heel length. Body and organ weights increase at varying rates throughout the second trimester. The data correlate well with weights and measurements previously published for the latter half of the second trimester, and extend these reference ranges to encompass the entire second trimester.

Crown-Rump Length↗

CELSS-3D: a broad computer model simulating a controlled ecological life support system.

CELSS-3D is a dynamic, deterministic, and discrete computer simulation of a controlled ecological life support system (CELSS) focusing on biological issues. A series of linear difference equations within a graphic-based modeling environment, the IThink program, was used to describe a modular CELSS system. The overall model included submodels for crop growth chambers, food storage reservoirs, the human crew, a cyanobacterial growth chamber, a waste processor, fixed nitrogen reservoirs, and the atmospheric gases, CO, O2, and N2. The primary process variable was carbon, although oxygen and nitrogen flows were also modeled. Most of the input data used in CELSS-3D were from published sources. A separate linear optimization program, What'sBest!, was used to compare options for the crew's vegetarian diet. CELSS-3D simulations were run for the equivalent of 3 years with a 1-h time interval. Output from simulations run under nominal conditions was used to illustrate dynamic changes in the concentrations of atmospheric gases. The modular design of CELSS-3D will allow other configurations and various failure scenarios to be tested and compared.

Atmosphere↗

Integer/linear mathematical programming models: a tool for allocating healthcare resources.

In today's environment, the demand for efficient healthcare resource allocation is increasing. As new technologies become available, allocation decisions become more complex and tools to assist decision makers in determining efficient allocations of healthcare resources are encouraged. Mathematical programs have multiple properties that are desirable for healthcare decision makers such as the simultaneous consideration of multiple constraints and a built-in sensitivity analysis. These models have been well researched and are considered invaluable in other industries. Mathematical programming has also become increasingly visible in facilitating the allocation of healthcare resources in the health services research sector. However, the use of mathematical programming tools has been limited in economic evaluations of new technologies. Budget allocations, such as formulary, drug development, and pricing decisions may benefit greatly from the use of mathematical programs. As an increasing number of expensive new technologies become available and pressure grows to contain healthcare costs, these tools may help guide a more efficient allocation of resources for technologies under budgetary and other constraints.

Decision Making↗

Genetic and phenotypic relationships among type traits scored linearly in Holsteins.

Phenotypic and genetic parameters were estimated for 12 type traits of Holstein cows scored linearly by personnel of an artificial insemination organization. Estimates were compared with those from programs offered by the breed association and by two other artificial insemination organizations. All programs were based on scoring guidelines of the National Association of Animal Breeders. Heritabilities of linear type traits ranged from .40 for stature to .14 for fore udder attachment with heritabilities for udder traits smaller than for nonudder traits. Largest genetic and phenotypic correlations were among udder traits with genetic correlations consistently exceeding phenotypic correlations. Similarities in relative magnitudes of phenotypic and genetic parameters suggest that linear type appraisal programs do not differ greatly among organizations using scoring guidelines of the National Association of Animal Breeders.

Animals↗

EUS Meets Voxel-Man: three-dimensional anatomic animation of linear-array endoscopic ultrasound images.

Endoscopic ultrasonography (EUS) is a widely used imaging modality in gastroenterology. The development of linear-array endoscopic ultrasound transducers, with facilities for EUS-guided diagnostic and therapeutic procedures, led to increasingly widespread use in different areas of the body. Examiners need to have excellent knowledge of anatomy. Orientation in linear EUS is more difficult and the learning curve is long. In an effort to shorten the training, reducing the risk to the patient and to allow a faster learning of the basic anatomic structures EUS meets VOXEL-MAN, an interactive three-dimensional anatomic simulation program has been developed for linear EUS for the purposes of private and independent study.

Anatomy, Artistic↗

Evaluation of centrifugation parameters for density gradient experiments by means of a programmable pocket calculator.

A calculation program is proposed suitable for programmable pocket calculators (e.g. HP series) to estimate s20,w f omega2 dt values from density gradient centrifugation data. The program can be applied to linear or exponential density gradients prepared from sucrose or glycerol solutions spun in zonal rotors or swinging bucket rotors. A wide solute concentration range and temperature range is accounted for. Constants for empirical density calculation of glycerol and sucrose solutions concentrated in % (w/v) are estimated. Experimental verification of the program was carried out.

Centrifugation, Density Gradient↗

Neural network and linear regression models in residency selection.

For many years, multiple linear regression models have been used at a residency program to generate preliminary rank lists of residency applicants. These lists are then used by the admissions committee as an aid in developing a final ranking to submit to the National Residency Match Program (NRMP). A study was undertaken to compare predictions made using linear regression with those generated by a newer technique, an artificial neural network. A prospective cohort design was used. Seventy-four applicants to an emergency medicine program were evaluated by faculty and resident interviewers with regard to medical school grades, autobiography, interviews, letters of recommendation, and National Board scores. Normalization of these scores (by linear transformation of interviewer means) was used to correct for differences among interviewers. Multivariate linear regression and neural network models were developed using data from the previous 5 years' applicants. These models were used to forecast provisional rank orderings of the candidates. These rankings were combined into a single hybrid list that was used by the admissions committee as the starting point for development of the final rank list by consensus. Each model's predictions were tested for goodness of fit against the final NRMP rank using Wilks' test. Using the final submitted NRMP rank order as the dependent variable, the neural network yielded a correlation coefficient of 0.77 and an R2 of 59.4%. The linear regression model exhibited a correlation coefficient of 0.74 and an R2 of 54.0%. No significant difference was found (chi 2 = 1.08, P = .7). A neural network performs as well as a linear regression model when used for forecasting the rank order of residency applicants.

Cohort Studies↗

Ontogeny of benzomorphan-selective (kappa) sites: a computerized analysis.

In an investigation of the postnatal development of kappa opiate receptors, the affinity and capacity of 0.5 nM [3H]-ethylketocyclazocine (EKC) binding in crude rat brain homogenates was measured by displacement with unlabeled EKC, morphine, or D-ala2-D-leu5-enkephalin (DADL). Displacement curves were analyzed using a weighted, non-linear regression, curve fitting computer program. At all stages of development, [3H]-EKC binding fit a two site model significantly better than a one site model. Affinities of EKC, morphine, or DADL for the high affinity [3H]-EKC binding site did not change during the postnatal period. The density of the high affinity [3H]-EKC binding site increased linearly with age, whereas the levels of the low affinity site rose more rapidly during the second week.

Aging↗

Somatic growth effects of perinatal addiction.

Intrauterine growth retardation occurs in a large percentage of infants born to mothers addicted to heroin during pregnancy. This is seen less often in infants of mothers who faithfully attended methadone programs. Postnatally, a decline in linear growth and head circumference is seen during the first year in both heroin- and methadone-exposed infants. The basis for this postnatal growth retardation requires further investigation. The birth weights, lengths and head circumferences were appropriate for gestational age in 28 of 29 infants delivered to mothers participating in methadone-maintenance programs three months or longer during pregnancy. Absence of intrauterine growth retardation seens to reflect the addict's improved lifestyle. Postnatally, growth distrubance occurred in 35% of infants exposed to heroin and 25% of infants exposed to methadone during gestation. Several cases of chronic unsuspected infections in addicts' infants are reported, raising the question of the significance of undiagnosed infection as it affects growth.

Birth Weight↗

Meta-analysis using linear mixed models.

Psychologists often use special computer programs to perform meta-analysis. Until recently, this had been necessary because standard statistical packages did not provide procedures for such analysis. This paper introduces linear mixed models as a framework for meta-analysis in psychological research, using a popular general purpose statistical package, SAS. The approach is illustrated with three examples, using SAS PROC MIXED.

Humans↗

Translating effective clinic-based physical activity interventions into practice.

An increasing number of studies report on the efficacy of physical activity interventions conducted in, or in conjunction with, clinical settings. This article reviews the status of the literature with regard to translation to practice and describes methods that will heighten the likelihood of translation. In general, few physical activity programs have been designed for translation, and the diffusion models underlying most reported programs have relied on an assumption of linear diffusion into practice. However, recent developments are encouraging and examples are provided of programs that utilize relationship or systems approaches to translation.

Cooperative Behavior↗

A simple computerized program for the calculation of the required sample size necessary to ensure statistical accuracy in medical experiments.

We developed a sample size estimation program (SSEP) with which medical researchers can easily estimate the appropriate sample size for a specific significance level and statistical power using their favorite WWW browsers. SSEP can estimate the sample sizes for six statistical methods by Monte-Carlo simulation: Student's t-test, Welch's t-test, Analysis of variance, Wilcoxon's rank sum test, Kruskal-Wallis test, and the Cochran-Armitage test for linear trends. The SSEP simulation programs were created using the SAS software macro language. Medical researchers can interactively use this program and determine reliable sample sizes when planning new prospective clinical studies and animal experiments.

Computer Simulation↗

Predictive correlates of treatment program completion in a sample of male alcoholics.

This study assessed the effectiveness of selected demographic and psychological variables in distinguishing between those male alcoholics who completed an 8-week inpatient treatment program at a Veterans Administration facility and those who left the program prematurely. Employing a stepwise multiple linear regression procedure resulted in nine variables of sufficient predictability to account for 25% of the variability in the criterion of program completion. Further application of the derived equation resulted in correct classification of 78% of the cases. This represented a 7% improvement over and above knowledge of the observed Stay-Split ratio. These findings were discussed in the context of a multidimensional conceptualization of alcoholism.

Alcoholism↗

[PHARMFIT--a program for the evaluation of digitally collected cardiovascular parameters].

The PHARMFIT program allows the non-linear fit of simple and combined cosine functions to data from long-term monitoring of cardiovascular parameters and the statistical evaluation of the quality of fit. With the SYNOPS utility a statistical comparison of different fit models can be achieved. As an example, the systolic blood-pressure data obtained in a hypertensive subject by ambulatory blood-pressure monitoring (ABPM) over a period of 36 h is used. The program demonstrates that the fit of a combined cosine function including a 24-h and a 12-h period describes the data better than a simple 24-h cosine function. The quality of fit is significantly improved by inclusion of the first harmonics. The PHARMFIT program can help to get a better analysis of ABPM data.

Blood Pressure↗

An analytical solution set for a four-compartment mixed mammillary/catenary model.

The purpose of this study was to extract the intercompartmental rate constants analytically from the coefficients and exponents of the exponential sum fitted to tracer data points for a unique four-compartment mixed mammillary/catenary (extended mammillary, radial) model, with losses solely from the central (blood) compartment. This model is useful in estimating myocardial and skeletal blood flow. Using Laplace transforms, the transfer functions of the exponential sum and the differential equations describing the model were obtained and the corresponding coefficients equated sequentially, which yielded the intercompartmental rate constants. Three solution sets of rate constants were found for the model, each of which satisfies both transfer functions. A program written in BASIC is provided, which requires only the coefficients and exponents of the exponential terms as input; the output is the three sets of rate constants. An example is given as an aid in debugging. Only one solution set of the three was physiologically realizable in the example, but the bounds defining these limits are not known. The advantages and limitations of the method are discussed. The method is suitable for initializing a non-linear least-squares fitting program for the rate constants. The appropriate physiological solution set for this model yields fractional and total myocardial or skeletal blood flow in a subject in the steady state.

Algorithms↗