Onset of Schamberg Disease and Resolution of Alopecia Areata During Treatment of Atopic Dermatitis With Dupilumab

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Model implementation for dynamic computation of system cost for advanced life support.

Life support system designs for long-duration space missions have a multitude of requirements drivers, such as mission objectives, political considerations, cost, crew wellness, inherent mission attributes, as well as many other influences. Evaluation of requirements satisfaction can be difficult, particularly at an early stage of mission design. Because launch cost is a critical factor and relatively easy to quantify, it is a point of focus in early mission design. The method used to determine launch cost influences the accuracy of the estimate. This paper discusses the appropriateness of dynamic mission simulation in estimating the launch cost of a life support system. This paper also provides an abbreviated example of a dynamic simulation life support model and possible ways in which such a model might be utilized for design improvement.

Analytical expression of effective afterload in aortic and mitral regurgitation.

Effective arterial elastance (Ea) is the coupling parameter between the left ventricle and peripheral circulation in normal subjects. If left ventricular end systolic pressure (Pes), contractility (Es) and Ea are known, left ventricular end diastolic volume (LVEDV) and ejection fraction of the ventricle are completely determined. The aim of this study was to give an analytical expression for Ea in patients with mitral and aortic regurgitation, and predict both LVEDV and the effect of vasodilator therapy on LVEDV. Twenty-three subjects with atypical chest pain, 15 patients with mitral insufficiency and 11 with aortic insufficiency underwent diagnostic cardiac catheterization, coronary angiography, and left ventricular cineangiography, which was analyzed quantitatively. Ea was 2.05 +/- 0.63 in normal subjects, while it was 1.28 +/- 0.71 and 1.57 +/- 0.87 in patients with mitral and aortic insufficiency, respectively. All these groups differed with ANOVA test (p = 0.0031). We tested the ability of the analytical expressions for Ea in normal subjects, and patients with mitral insufficiency or aortic insufficiency to predict measured Ea and LVEDV. Ea and LVEDV were predicted rather accurately in every case (p < 0.0001). We used published data to test the effect of resistance modulation on LVEDV. Predicted and measured LVEDV were linearly correlated both in aortic (p < 0.0001) and mitral insufficiency (p = 0.027). Moreover, in some cases a left ventricular enlargement after vasodilator therapy could be anticipated because of an unbalanced decrease in resistance and heart rate. Ea seems to be the coupling parameter between the left ventricle and the peripheral circulation not only in normal subjects, but also in patients with mitral or aortic regurgitation; its measurement before administering vasodilating drugs may be useful in order to predict the effects on LVEDV, and achieve an optimal ventriculoarterial coupling.

Multivariable empirical modeling of ALS systems using polynomials.

Multivariable polynomial regression (MPR) was used to model plant motion time-series and nutrient recovery data for Advanced Life Support (ALS). MPR has capabilities similar to neural network models in terms of ability to fit multiple-input single-output nonlinear data. It has advantages over neural networks including: reduced overfitting, produces models that are more tractable for optimization, sensitivity analysis, and prediction of confidence intervals. MPR was used to produce nonlinear polynomial time-series models predicting plant projected canopy area versus time and temperature. Temperature was found to not have a statistically significant effect. Models were developed to relate rate and extent of nutrient recovery to treatment parameters, including temperature and use of heat pretreatment or nutrient supplementation. These applications demonstrate MPR's capability to fill "gaps" in an integrated model of ALS. Fundamental models should be used whenever available. However, some components may require empirical modeling. Furthermore, even fundamental models often have empirical constituents. MPR models are proposed to satisfy these needs.

Nutrient recovery and biodegradation of inedible tomato plant residues by activated sludge cultures and Phanerochaete chrysosporium.

The biodegradation of inedible biomass and the recovery of nutrients from hydroponically grown tomato plant material were investigated under various growth conditions of activated sludge and the fungus Phanerochaete chrysosporium. The experiments were carried out in shaker flasks at three incubation temperatures (25 degrees C, 40 degrees C, and 60 degrees C for the activated sludge and 25 degrees C, 40 degrees C, and 50 degrees C for the fungi) with heat-pretreated samples at 150 degrees C for 30 min, and without pretreatment of the inedible residues. Under the experimental conditions tested, both cultures exhibited similar performance in terms of solids reduction and nutrient recovery. Solids reduction as high as 70% was obtained in both systems. Most of the solids degradation occurred the first 16 days of incubation. Cellulose degradation reached about 90% but no significant reduction in the solids lignin content was observed. Recovery of nitrogen (as NO2-N and NO3-N) and other micronutrients was sufficiently high and was accompanied by an average 70% reduction in COD, indicating that the final effluent is suitable for hydroponic plant growth. Incubation temperature had a minimal effect on solids degradation but appeared to influence the leachability of certain nutrients.

The "kynurenate test", a biochemical assay for putative cognition enhancers.

Some putative cognition enhancers (oxiracetam, aniracetam and D-cycloserine) were previously shown to prevent the kynurenic acid antagonism of the N-methyl-D-aspartate (NMDA)-evoked norepinephrine (NE) release in rat hippocampal slices. This functional in vitro assay was further characterized in the present work. D-Serine, a glutamate coagonist at the NMDA receptor glycine site, concentration-dependently (EC50 approximately 0.1 microM) prevented the kynurenate (100 microM) block of the NMDA (100 microM)-evoked [3H]NE release. L-Serine was ineffective up to 10 microM. The gamma-aminobutyric acidB (GABA[B]) receptor antagonist CGP 36742, reported to improve cognitive performance, potently prevented the kynurenate antagonism. The activity of CGP 36742 (1 microM) appeared to be unaffected by 10 microM (-)-baclofen, a GABA(B) receptor agonist; furthermore, CGP 52432, a GABA(B) antagonist more potent than CGP 36742, but reportedly devoid of nootropic properties, was inactive in the "kynurenate test." The novel putative cognition enhancer CR2249, but not its enantiomer CR2361, also potently prevented the kynurenate antagonism. In contrast, linopirdine, nicotine and tacrine were inactive. In rat hippocampal synaptosomes glycine and D-cycloserine enhanced the NMDA-evoked [3H]NE release, whereas oxiracetam and CR2249 did not. These four compounds were all similarly effective in preventing kynurenate antagonism, both in slices and in synaptosomes. The NMDA potentiation caused by glycine (0.1-100 microM) was not affected by 100 microM oxiracetam, which suggested that drugs active in the "kynurenate test" may bind to sites different from the glycine site of the NMDA receptor. To conclude, the "kynurenate test" is an in vitro assay useful in the identification and characterization of putative cognition enhancers acting via NMDA receptors.

Simulation of chronic mitral regurgitation.

In mitral regurgitation the left ventricle enlarges in order to increase its stroke volume because of the regurgitation through the mitral valve. The amount of this volume increase, and of the consequent increase in left ventricular mass, its dependent upon the amount of the regurgitant volume, but many other factors come into play, such as left ventricular pumping capability (contractility), the level of peripheral pressure, resistance and compliance of the arterial tree. The aim of this study is to predict the final left ventricular volumes and mass given the amount of mitral regurgitation. The predicted results are compared with actual data in real patients. In most cases prediction is fairly good; some discrepancies can be interpreted as an index of advanced decompensation.

Generalized multiple-regression techniques with interaction and nonlinearity for system identification in biological treatment processes.

A class of multiple regression models, called "generalized multiple-regression" (GMR) is proposed. GMR has the advantages of being easy and rapid to fit, and uses standard multilinear regression software. It has an advantage over ARIMA models in modeling nonlinearity and linear and nonlinear interactions among variables. Its main disadvantage is that, if there are many independent variables, the reduction of degrees of freedom may be important. It is less parsimonious than other models, but availability of increased computational power makes this not a serious disadvantage. The GMR models are compared to autoregressive transfer function models and feedforward back propagation neural network models. In the case of modeling effluent volatile suspended solids, GMR models were superior to both linear autoregressive models and neural network models. The neural network models did, however, outperform the linear models. In the case of modeling sludge volume index, both GMR and the neural network model were unable to improve upon ARIMA models. It was concluded that ARIMA models may, in some cases, produce the most parsimonious model, but in other cases they may miss important process behaviors. The GMR models showed robust capability to describe complex data.

Calculation of mean cell residence time for unsteady-state activated sludge systems.

A formulation to calculate the mean cell residence time (MCRT or sludge age) of unsteady-state activated sludge systems is presented. The formulation was studied by applying it to data generated by computer simulation and to data obtained from an actual wastewater treatment plant. The computer simulation study allowed the effects of step and pulse changes in biochemical oxygen demand (BOD) loading, and step changes in a control variable, waste sludge flow rate, to be studied independently of each other and of other disturbances. The unsteady-state MCRT formulation (herein called the dynamic sludge age, or DSA) was found to be an improvement over the traditional steady-state calculation, both for process control, and for research into activated sludge dynamics.