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PubMedDate not supplied

Rapid and sensitive quantitative analysis of alkyl phosphates in urine after organophosphate poisoning.

Organophosphate compounds are widely used as pesticides. After ingestion by humans, organophosphates decompose into alkyl phosphates. Decomposition continues postmortem. We developed a rapid (< 3 h), quantitative, and sensitive analysis of the human organosphosphate metabolites O,O-dimethylphosphate (DMP), O,O-diethylphosphate (DEP), O,O-dimethylthiophosphate (DMTP), O,O-diethylthiophosphate (DETP), O,O-dimethyldithiophosphate (DMDTP), and O,O-diethyldithiophosphate (DEDTP). Urine is dried under azeotropic conditions with isopropanol and nitrogen. All metabolites are converted into their corresponding benzyl esters reacting with benzyl bromide and diazotoluene. The protocol prevents the isomerization of DMTP and DETP occurring when diazo compounds are used exclusively. The benzyl ester derivatives are purified on solid-phase extraction silica columns. The quantitative analysis is performed by gas chromatography-mass spectrometry. All metabolites can be identified by the parent molecular ions. Urine samples from eight cases of fatal suicidal poisoning dialkyl phosphates were quantitated. The limits of detection ranged from 3 to 6 ng/mL. Hence, this protocol is sufficiently sensitive to detect and quantitate organophosphate metabolites beyond cases of fatal poisoning, in the clinical setting, and even following average environmental exposure.

Forensic Medicine↗
PubMedDate not supplied

Application of modelling techniques to the planning of in vitro arsenic kinetic studies.

A kinetic model describing the hepatic methylation of arsenite [As(III)] was developed on the basis of limited data from in vitro mechanistic studies. The model structure is as follows: sequential enzymic methylation of arsenite to its monomethylated (MMA) and dimethylated (DMA) products by first-order and Michaelis-Menten kinetics, respectively; uncompetitive inhibition of the formation of DMA by As(III); and first-order reversible binding of As(III), MMA and DMA to cytosolic proteins. Numerical sensitivity analysis was used to evaluate systematically the impact of changes in input parameters on model responses. Sensitivity analysis was used to investigate the possibility of designing experiments for robust testing of the uncompetitive inhibition hypothesis, and for further refining the model. Based on the sensitivity analysis, the MMA concentration is the most important response on which to focus. The parameters V(max) and k(i) can be reliably estimated by using the same concentration time-course data at intermediate initial arsenite concentrations of 1--5microM at 30 +/- 5 minutes. K(m) must be estimated independently of V(max), since the two parameters are highly correlated at all times, and the optimal experimental conditions would include lower initial concentrations of arsenite (0.1--0.5microM) and earlier time-points (about 8--18 minutes). The use of initial arsenite concentrations much above 5microM would not yield additional useful information, because the sensitivity coefficients for MMA, protein-bound MMA, DMA and protein-bound DMA tend to become extremely small or exhibit erratic trends. Overall trends in the sensitivity analysis indicated the desirability of performing measurements at times shorter than 60 minutes. This work demonstrates that physiological modelling and sensitivity analysis can be efficient tools for experimental planning and hypothesis testing when applied in the earliest phases of kinetic model development, thus allowing more-efficient and more-directed experimentation, and minimising the use of laboratory animals.

Animals↗
PubMed1990

Analysing clinical decision analyses.

We present a critical review of aspects of clinical decision analysis which uses an application to screening for familial intracranial aneurysms. The analysis is reported together with methods for assessing decision trees. These methods appear to be powerful checks on the usually rather intuitive way in which decision trees are built. The problem of assessing the uncertainty in the results of a decision analysis is discussed in detail. In practice, sensitivity analysis covers nearly every calculation apart from the standard evaluation of the decision tree. Different forms of sensitivity analysis are distinguished and given appropriate names: influence analysis, threshold analysis, full Bayesian analysis, Bayesian influence analysis, attribute analysis, generalization analysis and scenario analysis. The biostatistical community may well contribute to the much needed methodological improvement in decision analysis and its different forms of sensitivity analysis, especially if prepared to look beyond the standard statistical techniques.

Adult↗
PubMed2003

Drug-sensitivity pattern analysis for study of functional relationship between gene products.

We have developed a method that we call 'drug-sensitivity pattern analysis', or DSPA, for analysis of protein function. Cells are transfected with cDNA of the test molecule, followed by analysis of the sensitivity of the transfected cells to multiple growth-inhibitory drugs. If two cDNA products have similar functions, their transfected cells should show similar drug-sensitivity patterns. The cDNAs of some signaling molecules were transfected into NIH3T3 or Ha-ras-transformed NIH3T3 (ras-NIH) cells and stable transfectants, which expressed high amounts of the gene product, were isolated. Chemosensitivity of the transfected clone was compared with the parental cells by the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide method using more than 40 drugs. The chemosensitivity changes caused by the transfected gene were calculated and expressed numerically as 'drug chemosensitivity index' (DCI). When the DCI values were analyzed by regression analysis, a significant positive relationship between IkappaBalpha superrepressor and dominant-negative IKKbeta and an inverse relationship between p53 and Mdm2 were consistent with previous reports. Thus, the DSPA method is useful for identifying functional similarities between gene products.

3T3 Cells↗
PubMed2001

Diagnostic approach to a patient with suspected celiac disease: a cost analysis.

Serological testing is an important tool in the diagnostic work-up of suspected celiac disease. Our aim was to apply a decision analysis model to compare the costs of serological testing versus small bowel biopsy in the diagnostic work-up of celiac disease. A cost-minimization approach was employed. A decision analysis model with three diagnostic arms was designed using Data Version 3.5: anti-gliadin antibody versus endomysial antibody versus small bowel biopsy. Response to gluten-free diet was considered diagnostic of celiac disease; lack of response prompted a small bowel biopsy to definitively exclude celiac disease. Baseline probabilities were varied using sensitivity analysis. Sensitivity analysis revealed that the endomysial antibody strategy was least costly, provided the prevalence of celiac disease was less than 42%; above this anti-gliadin antibody became the most economical option. In conclusion, initial screening with endomysial antibody is the least costly strategy for diagnosing celiac disease in a low risk population. Antigliadin antibody becomes the cheaper strategy for higher risk populations.

Biopsy↗
PubMed1993

Cost-effectiveness of white cell-reduction filters in treatment of adult acute myelogenous leukemia.

The objective of this study was to compare the cost and cost-effectiveness of three transfusion strategies in the treatment of acute myelogenous leukemia: 1) the use of unfiltered pooled platelets until alloimmunization developed and of crossmatch-compatible single-donor platelets thereafter; 2) the use of filtered blood components until alloimmunization occurred and of crossmatch-compatible single-donor platelets thereafter; and 3) the use of single-donor platelets from the beginning. The data sources were English language articles on transfusion medicine in acute leukemia and the management of acute leukemia and review of the transfusion experience at the H. Lee Moffitt Cancer Center. The method was decision analysis with a software program for cost-effectiveness, sensitivity analysis, threshold evaluation, and Monte Carlo sensitivity analysis. In the basic models, the total costs of the first, second, and third strategies are, respectively, $12,557.14, $11,406.17, and $13,016.16 without bone marrow transplant and $14,002.72, $12,281.89, and $13,727.48 with bone marrow transplant. The threshold between the first and second strategies in regard to risk of refractoriness to filtered blood components and pooled platelets was 0.30 and 0.27, respectively, without bone marrow transplant and 0.28 and 0.40 with bone marrow transplant. According to a Monte Carlo sensitivity analysis of 500 samples, the second strategy is more cost-effective than the first in 76 percent of cases. It is concluded that the use of filtered blood components is unlikely to increase the cost of treatment.

Blood Component Transfusion↗
PubMed2005

Computation and analysis of time-dependent sensitivities in Generalized Mass Action systems.

Understanding biochemical system dynamics is becoming increasingly important for insights into the functioning of organisms and for biotechnological manipulations, and additional techniques and methods are needed to facilitate investigations of dynamical properties of systems. Extensions to the method of Ingalls and Sauro, addressing time-dependent sensitivity analysis, provide a new tool for executing such investigations. We present here the results of sample analyses using time-dependent sensitivities for three model systems taken from the literature, namely an anaerobic fermentation pathway in yeast, a negative feedback oscillator modeling cell-cycle phenomena, and the Mitogen Activated Protein (MAP) kinase cascade. The power of time-dependent sensitivities is particularly evident in the case of the MAPK cascade. In this example it is possible to identify the emergence of a concentration of MAPKK that provides the best response with respect to rapid and efficient activation of the cascade, while over- and under-expression of MAPKK relative to this concentration have qualitatively different effects on the transient response of the cascade. Also of interest is the quite general observation that phase-plane representations of sensitivities in oscillating systems provide insights into the manner with which perturbations in the envelope of the oscillation result from small changes in initial concentrations of components of the oscillator. In addition to these applied analyses, we present an algorithm for the efficient computation of time-dependent sensitivities for Generalized Mass Action (GMA) systems, the most general of the canonical system representations of Biochemical Systems Theory (BST). The algorithm is shown to be comparable to, or better than, other methods of solution, as exemplified with three biochemical systems taken from the literature.

Animals↗
PubMed2004

Modelling responses to a smallpox epidemic taking into account uncertainty.

Epidemiology and modelling are currently under pressure to build consistent scenarios of control in case of deliberate release of biological weapons. In order to assess the key parameters for the control of a smallpox outbreak in a large city (2 million inhabitants), we built a stochastic model to simulate the course of an epidemic controlled by ring vaccination and case isolation. Assuming a reference scenario with 100 index cases and implementation of intervention 25 days after the attack, the model forecasts an epidemic of 730 cases with an epidemic duration of 240 days. Setting intervention 20 days later would result in an almost fourfold increase in the epidemic size. A multivariate sensitivity analysis has selected three key parameters: the basic reproduction number (i.e. the number of secondary cases infected by one case in an entirely susceptible population, equal to 3 in the reference scenario), time to intervention, and proportion of traced and vaccinated contacts.

Algorithms↗
PubMed2004

Molecular-beacon-based array for sensitive DNA analysis.

Molecular beacon (MB) DNA probes provide a new way for sensitive label-free DNA/protein detection in homogeneous solution and biosensor development. However, a relatively low fluorescence enhancement after the hybridization of the surface-immobilized MB hinders its effective biotechnological applications. We have designed new molecular beacon probes to enable a larger separation between the surface and the surface-bound MBs. Using these MB probes, we have developed a DNA array on avidin-coated cover slips and have improved analytical sensitivity. A home-built wide-field optical setup was used for imaging the array. Our results show that linker length, pH, and ionic strength have obvious effects on the performance of the surface-bound MBs. The fluorescence enhancement of the new MBs after hybridization has been increased from 2 to 5.5. The MB-based DNA array could be used for DNA detection with high sensitivity, enabling simultaneous multiple-target bioanalysis in a variety of biotechnological applications.

Base Sequence↗
PubMed2006

Is shared care with annual hospital review better value for money than predominantly hospital-based care in patients with established stable rheumatoid arthritis?

OBJECTIVE: To assess the cost effectiveness and cost effectiveness acceptability of symptom control delivered by shared care (SCSC) and aggressive treatment delivered in hospital (ATH) for established rheumatoid arthritis (RA). METHODS: Economic data were collected within the British Rheumatoid Outcome Study Group randomised controlled trial of SCSC and ATH. A broad perspective was used (UK National Health Service, social support services and patients). Cost per quality adjusted life year (QALY) gained, net benefit statistics and cost effectiveness acceptability curves were estimated. Costs and outcomes were discounted at 3.5%. Sensitivity analysis tested the robustness of the results to analytical assumptions. RESULTS: The mean (SD) cost per person was 4540 pounds (4700) in the SCSC group and 4440 pounds (4900) in the ATH group. The mean (SD) QALYs per person for 3 years were 1.67 (0.56) in the SCSC group and 1.60 (0.60) in the ATH group. If decision makers are prepared to pay > or = 2000 pounds to gain 1 QALY, SCSC is likely to be cost effective in 60-90% of cases. CONCLUSIONS: The primary economic analysis and sensitivity analyses indicate that SCSC is likely to be more cost effective than ATH in 60-90% of cases. This result seems to be robust to assumptions required by the analysis. This study is one of a limited number of randomised controlled trials to collect detailed resource use and health status data and estimate the costs and QALYs of treatment for established RA. This trial is one of the largest RA studies to use the EuroQol.

Adult↗
PubMed2002

Diagnostic accuracy and factor structure of the AAS and APS scales of the MMPI-2.

Receiver operating characteristics analysis and sensitivity analysis were used to compare the diagnostic accuracy of the Addiction Acknowledgement Scale (AAS; Weed, Butcher, McKenna, & Ben-Porath, 1992) and Addiction Potential Scale (APS; Weed et al., 1992) of the Minnesota Multiphasic Personality Inventory-2 (Butcher, Dahlstrom, Graham, Tellegen, & Kaemmer, 1989) to that of the MacAndrew Alcoholism Scale-Revised (Butcher et al, 1989), the CAGE (Mayfield, McLeod, & Hall, 1974), and Svanum's scale (Svanum & McGrew, 1995) in a sample of 338 university students. The AAS was the most accurate of these 5 scales at identifying current alcohol dependence (as measured by a structured diagnostic interview) and appears to offer considerable promise as an alcohol screening instrument. In contrast, the APS performed the most poorly of the 5 scales being evaluated, yielding results that would be of minimal clinical utility. Factor analysis yielded a 2-factor solution for the AAS (Acknowledgement of Alcohol/Drug Problems; Positive Alcohol Expectancies) and a 4-factor solution for the APS (Satisfaction with Self; Cynicism/Pessimism; Impulsivity; Risk-Taking).

Adolescent↗
PubMed2003

Cost-effectiveness analysis of therapeutic strategies for patients with chronic hepatitis C previously not responding to interferon.

BACKGROUND: The efficacy of combination therapy in patients with chronic hepatitis C previously not responding to interferon monotherapy is lower than that in naive patients, and there has been no economic evaluation in this population. AIM: To develop a cost-effectiveness analysis of therapeutic regimens with interferon-alpha and ribavirin in previous interferon non-responders. METHODS: A Markov simulation model was used to project the clinical and economic outcomes of five different therapeutic strategies, including a 'no treatment' alternative, using the health care system perspective. The efficacy data for the different doses and durations were obtained from a previously performed meta-analysis. A sensitivity analysis was performed to test the robustness of the model, analysing changes in different variables. RESULTS: Applying a 3% discount rate, the standard patient on combination therapy for 12 months showed increases of 0.80 years and 1.55 quality-adjusted life years, when compared with the 'no treatment' strategy. This option led to an incremental cost-effectiveness ratio of 11,767 euros per year of life gained and 6073 euros per quality-adjusted life year. CONCLUSIONS: Combination therapy with interferon plus ribavirin is cost-effective in previous interferon non-responders and is within the range of some well-accepted medical interventions in our health care system.

Adult↗
PubMedDate not supplied

Intent-to-treat analysis for longitudinal clinical trials: coping with the challenge of missing values.

Drop-out is a common phenomenon in clinical trials of drug treatments involving longitudinal assessments for a fixed duration of follow-up. For these trials intent-to-treat (IT) analysis is usually preferred because time effects are seen in practice. The IT analysis mandates that all subjects randomized to a treatment arm should be included in the analysis. The purpose of the present paper is to acquaint both clinicians and statisticians with recent statistical methodological advances in handling drop-outs and their usage for IT analysis. We discuss a sensitivity analysis of 12-month outcome data to investigate the efficacy of drug therapy from a longitudinal double-blind placebo-controlled clinical trial in the maintenance therapy of geriatric major depressive illness. Outcome measures consist of monthly Hamilton depression scores. The sensitivity analysis includes endpoint analysis, last observation carried forward analysis, repeated measures models and imputation models. Imputation models are based on multiple imputations of missing responses deriving from an 'as-treated' model. The model used imputed doses from a plausible treatment scenario after drop-out and a 'propensity-adjusted' model where the imputations for the drop-outs were obtained from the adhering subjects with the same probability to remain on study (propensity) given the observed trajectory prior to withdrawal. Issues related to bias and efficiency of the estimates obtained by different analyses are discussed. We recommend a more widespread use of imputation models for the IT analysis.

Aged↗
PubMed2025

Identification and validation of prognostic genes associated with mitochondrial nuclear genes in gastric cancer.

Mitochondrial-related nuclear genes (MNGs) have shown great importance in cancer diagnosis and prognosis, but their role in gastric cancer (GC) remains unclear. GC-related transcriptome data from the gene expression omnibus and cancer genome atlas databases were analyzed to identify differentially expressed MNGs. A prognostic risk model was constructed through univariate Cox and least absolute shrinkage and selection operator regression, validated by Kaplan-Meier (K-M) survival curve and receiver operating characteristic curve. This was followed by immune infiltration analysis, independent prognostic analysis, functional enrichment analysis, drug sensitivity analysis, drug prediction, molecular docking and construction of regulatory networks. Three prognostic genes (ATP8A2, COX15 and TARS2) were identified. The expression of TARS2 and COX15 was positively correlated with CNV, while ATP8A2 was unaffected. The risk model and nomogram, integrating risk score and clinicopathological factors, exhibited excellent predictive performance. A significant correlation was observed between prognostic genes and differential immune cells, such as T cells, B cells, and NK cells. BMS-754807, Gefitinib, JQ1, Lapatinib, and Sapitinib exhibited significant differences in sensitivity between the high-risk group and the low-risk group. The results of molecular docking showed TP8A2 has stable binding ability with cytosine, COX15 with indomethacin, and TARS2 with bisacodyl. RT-qPCR revealed downregulation of ATP8A2 and upregulation of COX15 and TARS2 in GC samples. MNGs, including ATP8A2, COX15, and TARS2, demonstrated significant associations with immune infiltration, CNV, and prognostic outcomes of GC.

Humans↗
PubMedDate not supplied

A cost analysis comparing erythropoietin and red cell transfusions in the treatment of anemia of prematurity.

BACKGROUND: Anemia of prematurity is invariably observed in very low birth weight infants and may become symptomatic enough to be treated with packed red cell transfusions. Recently, treatment of this condition with recombinant human erythropoietin has been advocated. STUDY DESIGN AND METHODS: To compare the costs of training symptomatic anemia in hospitalized premature infants with transfusions alone or with erythropoietin plus red cell transfusions as needed, cost estimates were derived from local hospital and published cost data. Decision analysis and sensitivity analysis were applied to a "base case." The base case was derived from results of a multicenter erythropoietin trial in the United States in which premature infants received 500 U of erythropoietin per kg of body weight each week. Because erythropoietin treatment began on average at 3 weeks of life, when infants were clinically stable, they had already received 3.5 red cell transfusions. During the 6-week treatment period, erythropoietin-treated infants received significantly fewer additional transfusions: a mean of 1.6 versus 1.1. RESULTS: The base-case cost in 1993 dollars for treating anemia in hospitalized premature infants with erythropoietin and transfusions was $1,326. This was nearly twice the cost of conventional treatment with transfusions alone ($721). If the 6-week treatment period alone is considered, erythropoietin is 3.6 times more costly: $840 versus $235. CONCLUSION: The largest available US study using erythropoietin to treat anemia in premature infants has demonstrated a small, but significant, reduction in transfusion needs. However, this study's cost data alone do not justify the widespread use of erythropoietin in premature infants. When this issue is probed in great depth, sensitivity analyses demonstrate that major reductions in erythropoietin's cost and/or improvements in its effectiveness quite possibly will make its use economically more attractive.

Anemia, Neonatal↗
PubMed2005

A novel computer based expert decision making model for prostate cancer disease management.

PURPOSE: We propose a strategic, computer based, prostate cancer decision making model based on the analytic hierarchy process. We developed a model that improves physician-patient joint decision making and enhances the treatment selection process by making this critical decision rational and evidence based. MATERIALS AND METHODS: Two groups (patient and physician-expert) completed a clinical study comparing an initial disease management choice with the highest ranked option generated by the computer model. Participants made pairwise comparisons to derive priorities for the objectives and subobjectives related to the disease management decision. The weighted comparisons were then applied to treatment options to yield prioritized rank lists that reflect the likelihood that a given alternative will achieve the participant treatment goal. Aggregate data were evaluated by inconsistency ratio analysis and sensitivity analysis, which assessed the influence of individual objectives and subobjectives on the final rank list of treatment options. RESULTS: Inconsistency ratios less than 0.05 were reliably generated, indicating that judgments made within the model were mathematically rational. The aggregate prioritized list of treatment options was tabulated for the patient and physician groups with similar outcomes for the 2 groups. Analysis of the major defining objectives in the treatment selection decision demonstrated the same rank order for the patient and physician groups with cure, survival and quality of life being more important than controlling cancer, preventing major complications of treatment, preventing blood transfusion complications and limiting treatment cost. Analysis of subobjectives, including quality of life and sexual dysfunction, produced similar priority rankings for the patient and physician groups. Concordance between initial treatment choice and the highest weighted model option differed between the groups with the patient group having 59% concordance and the physician group having only 42% concordance. CONCLUSIONS: This study successfully validated the usefulness of a computer based prostate cancer management decision making model to produce individualized, rational, clinically appropriate disease management decisions without physician bias.

Brachytherapy↗
PubMed2001

Vocational rehabilitation for people with severe mental illness.

BACKGROUND: Unemployment rates are high amongst people with severe mental illness, yet surveys show that most want to work. Vocational rehabilitation services exist to help mentally ill people find work. Traditionally, these services have offered a period of preparation (Pre-vocational Training), before trying to place clients in competitive (i.e. open) employment. More recently, some services have begun placing clients in competitive employment immediately whilst providing on-the-job support (Supported Employment). It is unclear which approach is most effective. OBJECTIVES: To assess the effects of Pre-vocational Training and Supported Employment (for people with severe mental illness) against each other and against standard care (in hospital or community). In addition, to assess the effects of: (a) special varieties of Pre-vocational Training (Clubhouse model) and Supported Employment (Individual Placement and Support model); and (b) techniques for enhancing either approach, for example payment or psychological intervention. SEARCH STRATEGY: Searches were undertaken of CINAHL (1982-1998), The Cochrane Library (Issue 2, 1999), EMBASE (1980-1998), MEDLINE (1966-1998) and PsycLIT (1887-1998). Reference lists of eligible studies and reviews were inspected and researchers in the field were approached to identify unpublished studies. SELECTION CRITERIA: Randomised controlled trials of approaches to vocational rehabilitation for people with severe mental illness. DATA COLLECTION AND ANALYSIS: Included trials were reliably selected by a team of two raters. Data were extracted separately by two reviewers and cross-checked. Authors of trials were contacted for additional information. Relative risks (RR) and 95% confidence intervals (CI) of homogeneous dichotomous data were calculated. A random effects model was used for heterogeneous dichotomous data. Continuous data were presented in tables (there were insufficient continuous data for formal meta-analysis). A sensitivity analysis was performed, excluding poorer quality trials. MAIN RESULTS: Eighteen randomised controlled trials of reasonable quality were identified. The main finding was that on the primary outcome (number in competitive employment) Supported Employment was significantly more effective than Pre-vocational Training; for example, at 18 months 34% of people in Supported Employment were employed versus 12% in Pre-vocational Training (RR random effects (unemployment) 0.76 95% CI 0.64 to 0.89, NNT 4.5). Clients in Supported Employment also earned more and worked more hours per month than those in Pre-vocational Training. There was no evidence that Pre-vocational Training was more effective in helping clients to obtain competitive employment than standard community care. REVIEWER'S CONCLUSIONS: Supported employment is more effective than Pre-vocational Training in helping severely mentally ill people to obtain competitive employment. There is no clear evidence that Pre-vocational Training is effective.

Employment↗
PubMed2005

Parameter and observation importance in modelling virus transport in saturated porous media-investigations in a homogenous system.

This paper evaluates the importance of seven types of parameters to virus transport: hydraulic conductivity, porosity, dispersivity, sorption rate and distribution coefficient (representing physical-chemical filtration), and in-solution and adsorbed inactivation (representing virus inactivation). The first three parameters relate to subsurface transport in general while the last four, the sorption rate, distribution coefficient, and in-solution and adsorbed inactivation rates, represent the interaction of viruses with the porous medium and their ability to persist. The importance of four types of observations to estimate the virus-transport parameters are evaluated: hydraulic heads, flow, temporal moments of conservative-transport concentrations, and virus concentrations. The evaluations are conducted using one- and two-dimensional homogeneous simulations, designed from published field experiments, and recently developed sensitivity-analysis methods. Sensitivity to the transport-simulation time-step size is used to evaluate the importance of numerical solution difficulties. Results suggest that hydraulic conductivity, porosity, and sorption are most important to virus-transport predictions. Most observation types provide substantial information about hydraulic conductivity and porosity; only virus-concentration observations provide information about sorption and inactivation. The observations are not sufficient to estimate these important parameters uniquely. Even with all observation types, there is extreme parameter correlation between porosity and hydraulic conductivity and between the sorption rate and in-solution inactivation. Parameter estimation was accomplished by fixing values of porosity and in-solution inactivation.

Adsorption↗