[Strain identification with hematological parameter in Japanese white rabbits].
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Animals↗
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Results for “parameter identification”
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[Identification of the parameters of single-compartment models of the intravenous glucose tolerance test (review of the literature)].
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Glucose Tolerance Test↗
[Identification of the parameters of 2-compartment models of the intravenous glucose tolerance test].
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Adult↗
[A mathematical description of ligand-receptor interaction and computer identification of its parameters].
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Algorithms↗
Model of the heat exchange in man and identification of its parameters (physiological studies and mathematical simulation).
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Body Temperature Regulation↗
[Clinical-experimental models for the identification of immunologic parameters to be integrated in traditional staging systems of colorectal neoplasms].
The Authors evaluate new possible models for the staging of colorectal cancer based on clinico-morphological, histo-pathological and bio-immunological parameters. Particularly, they evaluate the possibility of studying host's immunological response against tumor spread by the examination of the "in situ" cellular responses. This study was performed by cytotoxic test and immunohistochemical evaluation of the lymphocytes. The latter seems to give better results compared to the first in the evaluation of the host's immunological response.
Colorectal Neoplasms↗
Computer modeling and analysis of heterogeneous structures of microporous carbonaceous materials.
The aim of this work was to study the problems connected with computer modeling and analysis of heterogeneous structures of microporous carbonaceous materials. The research was focused on the numerical properties of original mathematical models for heterogeneous multilayer adsorption on microporous carbonaceous materials presented in our earlier papers and their applicability to examination of real microporous materials. These models are aimed at drawing information on pore structure and capacity on the basis of adsorption isotherms of small molecule adsorbates. They easily fit typical adsorption data in wide relative pressure ranges. In the theory presented, adsorption of small nearly spherical molecules in irregular pores of molecular size has been considered and side adsorbate-adsorbate interactions are neglected. The molecules mentioned are located in pores by forming aggregates, the size of which is limited by the geometry of the pores. The set of adsorbate molecules, which were adsorbed mainly due to adhesive interactions with the adsorbent matter, is treated as the first layer adsorption. Joining further molecules is viewed as the second, third,... layer adsorption. The main idea of the approach to modeling microporous structure presented, consists of introducing of realistic relationships between geometrical properties of pores and adsorption energy. Special attention was focused on the analysis of the influence of the number of model parameters on identification reliability and evaluation errors of porous structure parameters. This paper gives more information on properties of the identification technique presented in our earlier papers. The five-parameter and six-parameter identification reliability is analyzed in more detail, for different values of the system parameters. In this context, the efficiency of simultaneous examination of two isotherms is also studied.
Adsorption↗
Blind identification of the kinetic parameters in three-compartment models.
Quantified knowledge of tissue kinetic parameters in the regions of the brain and other organs can offer information useful in clinical and research applications. Dynamic medical imaging with injection of radioactive or paramagnetic tracer can be used for this measurement. The kinetics of some widely used tracers such as [18F]2-fluoro-2-deoxy-D-glucose can be described by a three-compartment physiological model. The kinetic parameters of the tissue can be estimated from dynamically acquired images. Feasibility of estimation by blind identification, which does not require knowledge of the blood input, is considered analytically and numerically in this work for the three-compartment type of tissue response. The non-uniqueness of the two-region case for blind identification of kinetic parameters in three-compartment model is shown; at least three regions are needed for the blind identification to be unique. Numerical results for the accuracy of these blind identification methods in different conditions were considered. Both a separable variables least-squares (SLS) approach and an eigenvector-based algorithm for multichannel blind deconvolution approach were used. The latter showed poor accuracy. Modifications for non-uniform time sampling were also developed. Also, another method which uses a model for the blood input was compared. Results for the macroparameter K, which reflects the metabolic rate of glucose usage, using three regions with noise showed comparable accuracy for the separable variables least squares method and for the input model-based method, and slightly worse accuracy for SLS with the non-uniform sampling modification.
Algorithms↗
Identification of driver model parameters.
The paper presents a driver model, which can be used in a computer simulation of a curved ride of a car. The identification of the driver parameters consisted in a comparison of the results of computer calculations obtained for the driver-vehicle-environment model with different driver data sets with test results of the double lane-change manoeuvre (Standard No. ISO/TR 3888:1975, International Organization for Standardization [ISO], 1975) and the wind gust manoeuvre. The optimisation method allows to choose for each real driver a set of driver model parameters for which the differences between test and calculation results are smallest. The presented driver model can be used in investigating the driver-vehicle control system, which allows to adapt the car construction to the psychophysical characteristics of a driver.
Automobile Driving↗
A formula for prediction of posttraumatic pneumonia based on early anatomic and physiologic parameters.
BACKGROUND: Identification of risks for development of ventilator-associated pneumonia (VAP), which might be identified early after injury, would allow for prognostic estimates and targeting of high-risk cohorts for clinical trials of preventive strategies. This study was performed to develop an equation that can be applied to estimate the probability of pneumonia based on parameters collected in the early postinjury interval. METHODS: Over a 28-month period, patient admissions were reviewed for mechanism and severity of injury, patterns of injury, shock, and need for emergent intubation. Early deaths (<48 hours) were excluded. VAP diagnosis required > or = 10(5) colony-forming units/mL organisms in the bronchoalveolar lavage effluent. Multiple logistic regression analysis was used to develop the prediction equation and estimate odds ratios. The equation was then tested on consecutive patients admitted over a 2-month period. RESULTS: We reviewed 9,721 admissions (77% blunt, 23% penetrating). VAP incidence was 5.6%. Overall mortality was 2% (21% for patients with VAP vs. 1% for no VAP; p < 0.0001). Multiple logistic regression analysis for all patients produced the following equation: f(x) = -3.08 - 1.56 (MOI) - 0.12 (GCS) + 1.37 (SCI) + 0.30 (chest AIS) + 1.87 (lap) + 0.67 (tx) + 0.05 (ISS) + 0.66 (int), where MOI is mechanism of injury (penetrating = 1, blunt = 0), GCS is Glasgow Coma Scale score, SCI is spinal cord injury (yes = 1, no = 0), lap is emergent laparotomy (yes = 1, no = 0), ISS is Injury Severity Score, tx is units of blood transfused in the resuscitation room, and int is intubation in either the field or the resuscitation room (yes = 1, no = 0). The probability of VAP was calculated as follows: P(VAP) = e(f)(x)/1 + e(f)(x). This formula was concordant in 95% and discordant in 5%. CONCLUSION: It is possible to accurately predict risk for VAP in trauma patients based on data available early after injury. This calculation could be useful for counseling families relative to prognosis and research protocols, and addressing hospitalization issues with third-party payors.
Adult↗
Biologic characterization of hereditary non-polyposis colorectal cancer. Nuclear ploidy, AgNOR count, microvessel distribution, oncogene expression, and grade-related parameters.
The identification of hereditary non-polyposis colorectal cancer (HNPCC) is important not only for the patient, but also for family members who are at increased risk of developing cancer. To determine if measuring various pathobiologic features of the colon carcinomas is useful in separating sporadic from HNPCC tumors, the authors studied tumor tissues from 46 patients with HNPCC and compared them to 70 with sporadic colorectal carcinoma. Parameters investigated included DNA ploidy (flow cytometry), AgNOR count (by silver staining), microvessel density (immunohistochemistry), p53 and K-ras expression, and grade-related parameters. Diploid tumors were more frequent in patients with HNPCC (65% vs 40%, P < .02), thus confirming previous observations concerning such an association. Higher AgNOR counts and greater AgNOR areas were observed in sporadic tumors than in HNPCC (5.2 +/- 1.5 vs 4.5 +/- 1.8, P < .01). Hereditary tumors tended to be less vascularized, whereas oncogene expression and grade-related parameters did not show appreciable differences between the two types of tumors. In conclusion, some of the investigated parameters may contribute to defining the biologic profile of HNPCC. In addition, these findings support the clinical impression of a more favorable outcome that is frequently seen in HNPCC patients.
Adult↗
Identification of dynamic mechanical parameters of the human chest during manual cardiopulmonary resuscitation.
Survival from cardiac arrest is dependent on timely cardiopulmonary resuscitation (CPR). Since CPR is often unsuccessful, the outcome may be improved by a better understanding of the relationship between force applied to the sternum and the resulting hemodynamic effects. The first step in this complex chain of interactions is the mechanical response of the chest wall to cyclical compression. We formulated a dynamic mechanical model of the chest response and developed a method of identification of the model parameters based on force, displacement, and acceleration data acquired during cyclical compressions. The elasticity, damping, and equivalent mass of the human chest were estimated with a constrained nonlinear least-mean-square identification technique. The method was validated on data acquired from a test apparatus built for this purpose. The model fit was measured with the normalized chi-square statistic on residuals obtained between recorded force and force predicted by the model. In the analysis of one human chest, the elasticity was found to be nonlinear and statistically different during compression and release. A considerable amount of damping was found, with no significant difference between compression and release. The equivalent mass was too small to be determined accurately. This method can be used to obtain the dynamic mechanical parameters of the human chest and may lead to a better understanding of CPR.
Biomechanical Phenomena↗
Histological parameters useful in the identification of multiple bloodmeals in mosquitoes.
Culex nigripalpus females were given double and, in 2 cases, triple (interrupted) bloodmeals separated by various intervals. Mosquitoes given single meals served as controls. Using Azan-stained serial paraffin sections, we could identify multiple meals separated by 1-72 hr in 44 of 53 cases (84.6%). Among the histological parameters of importance in the identification of double and triple bloodmeals are the peritrophic membrane secreted around each bloodmeal, the plug which forms between the anterior and posterior midgut, the layer of heme which forms as a bloodmeal is digested, and remnants of the pupal meconium and/or pupal-pharate adult peritrophic membranes. The parameters we have identified will help determine the incidence of double bloodfeeding in wild populations which, in turn, should enhance our understanding of the transmission of pathogens by mosquitoes.
Animals↗
Sensor fault diagnosis for nonlinear processes with parametric uncertainties.
This paper addresses the problem of detecting, discriminating, and reconstructing sensor faults for nonlinear systems with known model structure but uncertainty in the parameters of the process. The convenience of the proposed technique lies in the fact that historical operational data and/or a priori fault information is not required to achieve accurate fault reconstruction except for fixed, short intervals. The overall fault diagnosis algorithm is composed of a series of nonlinear estimators, which estimates parameter and a fault isolation and identification filter. Parameter estimation and fault reconstruction cannot be performed accurately since faults and parametric uncertainty interact with each other. Therefore, these two tasks are performed at different time scales, where the fault diagnosis takes place at a more frequent rate than the parameter estimation. It is shown that the fault can be reconstructed under some realistic assumptions and the performance of the proposed methodology is evaluated on a simulated chemical process exhibiting nonlinear dynamic behavior.
Algorithms↗
Deterministic vs. probabilistic analyses to identify sensitive parameters in dose assessment using RESRAD.
The dose assessments for sites containing residual radioactivity usually involve the use of computer models that employ input parameters describing the physical conditions of the contaminated and surrounding media and the living and consumption patterns of the receptors in analyzing potential doses to the receptors. The precision of the dose results depends on the precision of the input parameter values. The identification of sensitive parameters that have great influence on the dose results would help set priorities in research and information gathering for parameter values so that a more precise dose assessment can be conducted. Two methods of identifying site-specific sensitive parameters, deterministic and probabilistic, were compared by applying them to the RESRAD computer code for analyzing radiation exposure for a residential farmer scenario. The deterministic method has difficulty in evaluating the effect of simultaneous changes in a large number of input parameters on the model output results. The probabilistic method easily identified the most sensitive parameters, but the sensitivity measure of other parameters was obscured. The choice of sensitivity analysis method would depend on the availability of site-specific data. Generally speaking, the deterministic method would identify the same set of sensitive parameters as the probabilistic method when 1) the baseline values used in the deterministic method were selected near the mean or median value of each parameter and 2) the selected range of parameter values used in the deterministic method was wide enough to cover the 5th to 95th percentile values from the distribution of that parameter.
Agriculture↗
Evaluation of pertinent parameters of a new identification system for non-enteric gram-negative rods.
The API 20 NE (Rapid NFT) system for identification of non-enteric aerobic gram-negative rods was evaluated using 431 strains of species covered by the analytical profile index and previously identified by conventional methods. In an analysis of several parameters, 343 (80%) of the strains were identified correctly with good to excellent probabilities of positive reactions (80.0-99.9%), 190 (55%) of these within 24 h; 74 (17%) yielded primary identifications with lower probabilities. Only 3% of the strains could not be correctly identified. The system is very satisfactory for routine use, but could be improved by modified pre-testing of the strains and by including more species in the profile index.
Bacteriological Techniques↗
May-Grünwald-Giemsa stain for detection of spermatogenic cells in the ejaculate: a simple predictive parameter for successful testicular sperm retrieval.
BACKGROUND: Testicular sperm extraction (TESE) and intracytoplasmic sperm injection (ICSI) have become standard treatments for patients with non-obstructive azoospermia. A diagnostic testicular biopsy for histopathological examination is not always predictive of TESE outcome. Moreover, it is not without potential complications. The aim of this study was to determine the value of various clinical and laboratory parameters, particularly identification of seminal spermatids using May-Grünwald-Giemsa (MGG) stain in predicting TESE results. METHODS: A total of 100 patients with non-obstructive azoospermia was subjected to clinical examination, serum FSH measurement, identification of seminal spermatids and spermatocytes using MGG staining and TESE with multiple testicular sampling. Spermatozoa were retrieved from 49% of patients. Results of TESE were compared with previous parameters in addition to histopathology. RESULTS: Testicular histopathology was, in general, an inaccurate parameter, and identification of testicular spermatids by histology predicted successful TESE in only 74% of cases. Testicular volume and serum FSH concentration also had poor predictive values. Round spermatids were identified in the ejaculate of 83.7% of TESE-positive cases, and in 22% of TESE-negative cases. CONCLUSIONS: The detection of round spermatids in semen by MGG staining provides the greatest predictive value for successful testicular sperm retrieval, and also has the advantages of simplicity, low cost and availability.
Adult↗
[Identification of radiopharmaceutical transport models in functional radionuclide diagnosis].
The paper is devoted to the problems of assessment of structural identification of parameters of compartmental models, employed for processing of the results of radionuclide investigations of function of various physiological systems. Methods for assessment of structural identifiability and a regularized algorithm for the identification of parameters of linear and nonlinear compartmental models of almost any structure were proposed. The algorithm possesses a high rate of convergence of the iteration searching process and a low sensitivity to errors of measurements. It was implemented as a software package in Pascal language and utilized on a RDR 11/34 computer for processing the results of radionuclide diagnosis (using 99mTc-COREN) of function of the reticuloendothelial system.
Algorithms↗