Local sensitivities

Local sensitivity analysis and Morris One-At-A-Time analysis were performed on the simple model, and showed... 

Fig. 10. Local Sensitivity Analysis of HO2 between 06 00 and Fig. 11. Morris One-At-a-Time Analysis of OH for 7 February. 18 00 (7 February). Only the most significant parameters are indicated (std is standard...

Local sensitivity analysis is of limited value when the chemical system is non-linear. In this case global methods, which vary the parameters over the range of their possible values, are preferable. Two global uncertainty methods have been used in this work, a screening method, the so-called Morris One-At-A-Time (MOAT) analysis and a Monte Carlo analysis with Latin Hypercube Sampling (Saltelli et al., 2000 Zador et al., submitted, 20041). The analyses were performed by varying rate parameters, branching ratios and constrained concentrations within their uncertainty interval,... 

The rate of production analysis was complemented by a local sensitivity analysis and by a global Morris screening analysis. These analyses demonstrate the necessity of accurate measurements of j(0 D) and [HCHO] and reduced uncertainty in the quantum yields for H from HCHO photolysis. 

Despite the obvious correspondence between scaled elasticities and saturation parameters, significant differences arise in the interpretation of these quantities. Within MCA, the elasticities are derived from specific rate functions and measure the local sensitivity with respect to substrate concentrations [96], Within the approach considered here, the saturation parameters, hence the scaled elasticities, are bona fide parameters of the system without recourse to any specific functional form of the rate equations. Likewise, SKM makes no distinction between scaled elasticities and the kinetic exponents within the power-law formalism. In fact, the power-law formalism can be regarded as the simplest possible way to specify a set of explicit nonlinear functions that is consistent with a given Jacobian. Nonetheless, SKM seeks to provide an evaluation of parametric representation directly, without going the loop way via auxiliary ad hoc functions. 

The sensitivity analysis of a system of chemical reactions consist of the problem of determining the effect of uncertainties in parameters and initial conditions on the solution of a set of ordinary differential equations [22, 23], Sensitivity analysis procedures may be classified as deterministic or stochastic in nature. The interpretation of system sensitivities in terms of first-order elementary sensitivity coefficients is called a local sensitivity analysis and typifies the deterministic approach to sensitivity analysis. Here, the first-order elementary sensitivity coefficient is defined as the gradient... 

For a local sensitivity analysis, Eq. (2.69) may be differentiated with respect to the parameters a to yield a set of linear coupled equations in terms of the elementary sensitivity coefficients, cXM /daj. 

Testosterone gel is effective transdermally, although a report on its use in the form of AA2500 (brand name), which releases 50 or 100 mg/day, points to an unusually high incidence of local sensitivity reactions it is not clear whether this is due to testosterone itself or to excipients absent from the placebo comparator (61). 

Intranasal administration of the antigen allows a local sensitization to develop. This initial intranasal challenge induces little cellular infiltration into the lungs of the mice upon histological examination. 

Dorzolamide is generally well tolerated. Ocular side effects include local irritation, possibly related to pH and tonicity. Stinging (7%), burning or foreign body sensation (12%), and blurring of vision (9%) are among the most common. Others include superficial punctate keratitis and headache. A severe sterile purulent conjunctivitis developing over weeks to months was described in seven patients and resolved on discontinuation of dorzolamide. Because all CAIs are sulfonamides, local sensitization has... 

Sensitivity analysis investigates the output of models as a function of parameters. In local sensitivity analysis, this relation is given as the partial derivative of the output of the model with respect to the parameters. These partial derivatives can be simply introduced via a Taylor series expansion ... 

Local sensitivity information has numerous applications in uncertainty analysis, parameter estimation, experimental design, mechanism investigation and mechanism reduction. Uncertainty analysis, a quantitative study of the effect of parameter uncertainties on the solution of models, is... 

This equation is identical to equation (4.6) which has been applied to the calculation of local sensitivities, but it can also be used for finding rate-limiting steps. The rate-limiting steps of the ith species can be identified (if they exist) by searching for very large elements in the ith row of the matrix... 

The local concentration sensitivity matrix shows the effect of equal perturbations of parameters. This means equal unit perturbation in the units of each parameter for the case of the original sensitivity matrix, and unit fractional (percentage) perturbation in the case of the normed sensitivity matrix. The local sensitivity matrix itself does not carry any information on the uncertainty of parameters. 

The local sensitivities can be used for a rough assessment of the parameter uncertainties on model output. The variance of the model output cr (c, ) can be estimated from the variance of the parameters (r kj) and the local sensitivities,... 

Application of formal uncertainty analysis to combustion systems has been very rare so far, and restricted to the utilization of local sensitivities. 

Cross-reactions between phenothiazine tranquillizers and first-generation antihistamines are possible, as well as reactions between antihistamines and ethylenediamine present in some creams and ointments. As local sensitization is quite common, topical use of antihistamines is not recommended. Despite these disadvantages they are stiU available in many countries as over-the-counter products. Topical antihistamines in sufficient doses can also cause systemic adverse effects. 

Local anesthesia began in Vienna (1884) when Carl KoUer administered cocaine, locally, over cornea, in order to anaesthetize the eye before cataract surgery. He noticed that the drug was able to prevent the oculomotor reflex in frogs. Cocaine had been previously isolated from coca leaves by Albert Nieman in 1860. Before this founding step, local sensitivity could be abolished by the dermal administration of organic derivatives like diethyl ether or ethylene chloride on the skin. Few years later, WiUiam Halsted in the United States used cocaine... 

Local SA involves repeated groups of simulations, where in each group a fixed-point perturbation of one parameter is used for the simulations. Trial simulation output metrics are then calculated for each group and the impact on outcome is considered relative to this range of parameter estimates. For example, the degree of sensitivity may be considered by the rate of change in response relative to the unit change in the parameter. This process is then repeated for each parameter of interest. Limitations of the local sensitivity approach are that it only reflects sensitivity to uncertainty in one parameter or assumption at a time. It is therefore inefficient and conclusions about sensitivity are conditional on assumptions of all other parameters. 

HUMAN HEALTH RISKS Skin man TDLo 20 mg/kg for 6 weeks EPA Group B2/C probable human carcinogen Acute Risks irritation of eyes, skin, nose and throat itchiness headache seizures respiratory failure nausea vomiting diarrhea tremors weakness anemia convulsions cyanosis Chronic Risks local sensitivity effects on liver, blood, cardiovascular and immune systems. 

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