857 research outputs found
Total nuclear disarmament: ethical and moral issues
Moving focus from the geostrategic and political realms to ethical and moral ones can lead to a better understanding of the paradox of “guaranteeing peace” by means of implementing an . infrastructure for the extinction of mankind (i.e. the nuclear weapons industry). A possible way forward is derived from this major paradigm shift. The analysis is contextualized within the broader scope of questioning the implicit legitimization of unrestrained tampering with nature, from matter to life
MPC performance monitoring of a rigorously simulated industrial process
We address in this paper the application of a recently proposed MPC performance monitoring method to a rigorously simulated industrial process. The methodology aims at detecting possible sources of suboptimal performance of linear offset-free MPC algorithms by analysis of the prediction error sequence, discriminating between the presence of plant/model mismatch and incorrect disturbance/state estimation, and proposing for each scenario an appropriate corrective action. We focus on the applicability of the method to large-scale industrial systems, which typically comprise a block structure, devising efficient and scalable diagnosis and correction procedures. We also discuss and support the application of this method when the controlled plant shows a mild nonlinear behavior mainly associated with operating point changes. A high-fidelity dynamic simulation model of a crude distillation unit was developed in UniSim® Design and used as representative test bench. Results show the efficacy of the method and indicate possible research directions for further improvements. © IFAC
Application of a method to diagnose the source of performance degradation in MPC systems
Model Predictive Control systems may suffer from performance degradation mainly for two reasons: (i) external unmeasured disturbances are not estimated correctly, (ii) the (linear) dynamic model used by the MPC does not match (any longer) the actual process response. In this work we present the application of a method to detect when performance is not optimal, to diagnose the source of performance degradation and to propose appropriate corrections. In the simplest situation (i), optimal performance can be restored by recomputing the estimator parameters; in the other case (ii), re-identification becomes necessary. The method is based on analysis of the prediction error, i.e. the difference between the actual measured output and the corresponding model prediction, and uses three main tools: a statistical (whiteness) test on the prediction error sequence, a subspace identification method to detect the order of the input-to-prediction error system, and a nonlinear optimization algorithm to recompute optimal estimator parameters. We illustrate the effectiveness of the method on a large-scale rigorously simulated industrial process. Copyright © 2013, AIDIC Servizi S.r.l
Maximum Agreement Linear Prediction via the Concordance Correlation Coefficient
This paper examines distributional properties and predictive performance of
the estimated maximum agreement linear predictor (MALP) introduced in Bottai,
Kim, Lieberman, Luta, and Pena (2022) paper in The American Statistician, which
is the linear predictor maximizing Lin's concordance correlation coefficient
(CCC) between the predictor and the predictand. It is compared and contrasted,
theoretically and through computer experiments, with the estimated
least-squares linear predictor (LSLP). Finite-sample and asymptotic properties
are obtained, and confidence intervals are also presented. The predictors are
illustrated using two real data sets: an eye data set and a bodyfat data set.
The results indicate that the estimated MALP is a viable alternative to the
estimated LSLP if one desires a predictor whose predicted values possess higher
agreement with the predictand values, as measured by the CCC
Low-dose synthetic adrenocorticotropic hormone-analog therapy for nephrotic patients: results from a single-center pilot study.
Introduction: This report describes our experience using a low-dose synthetic adrenocorticotropic hormone (ACTH) analog for patients affected by nephrotic syndrome who had not responded to or had relapsed after steroid and immunosuppressive treatments.
Patients and methods: Eighteen adult nephrotic patients with an estimated glomerular filtration rate.30 mL/min were recruited. Histological pictures included ten of membranous nephropathy, three of membranous proliferative glomerulonephritis, three of minimal change, and two of focal segmental glomerular sclerosis. All patients received the synthetic ACTH analog tetracosactide 1 mg intramuscularly once a week for 12 months. Estimated glomerular filtration rate, proteinuria, serum lipids, albumin, glucose, and potassium were determined before and during the treatment.
Results: One of the 18 patients discontinued the treatment after 1 month because of severe fluid retention, and two patients were lost at follow-up. Complete remission occurred in six cases, while partial remission occurred in four cases (55.5% responder rate). With respect to baseline, after 12 months proteinuria had decreased from 7.24±0.92 to 2.03±0.65 g/day (P,0.0001), and serum albumin had increased from 2.89±0.14 to 3.66±0.18 g/dL (P,0.0001). Total and low-density lipoprotein cholesterol had decreased from 255±17 to 193±10 mg/dL (P=0.01), and from 168±18 to 114±7 mg/dL (P=0.03), respectively. No cases of severe worsening of renal function, hyperglycemia, or hypokalemia were observed, and no admissions for cardiovascular or infectious events were recorded.
Conclusion: Tetracosactide administration at the dosage of 1 mg intramuscularly per week for 12 months seems to be an acceptable alternative for nephrotic patients unresponsive or relapsing after steroid-immunosuppressive regimens. Further studies should be planned to assess the effect of this low-dose ACTH regimen also in nephrotic patients not eligible for kidney biopsy or immunosuppressive protocols.Introduction: This report describes our experience using a low-dose synthetic adrenocorticotropic hormone (ACTH) analog for patients affected by nephrotic syndrome who had not responded to or had relapsed after steroid and immunosuppressive treatments.Patients and methods: Eighteen adult nephrotic patients with an estimated glomerular filtration rate.30 mL/min were recruited. Histological pictures included ten of membranous nephropathy, three of membranous proliferative glomerulonephritis, three of minimal change, and two of focal segmental glomerular sclerosis. All patients received the synthetic ACTH analog tetracosactide 1 mg intramuscularly once a week for 12 months. Estimated glomerular filtration rate, proteinuria, serum lipids, albumin, glucose, and potassium were determined before and during the treatment.Results: One of the 18 patients discontinued the treatment after 1 month because of severe fluid retention, and two patients were lost at follow-up. Complete remission occurred in six cases, while partial remission occurred in four cases (55.5% responder rate). With respect to baseline, after 12 months proteinuria had decreased from 7.24±0.92 to 2.03±0.65 g/day (P,0.0001), and serum albumin had increased from 2.89±0.14 to 3.66±0.18 g/dL (P,0.0001). Total and low-density lipoprotein cholesterol had decreased from 255±17 to 193±10 mg/dL (P=0.01), and from 168±18 to 114±7 mg/dL (P=0.03), respectively. No cases of severe worsening of renal function, hyperglycemia, or hypokalemia were observed, and no admissions for cardiovascular or infectious events were recorded.Conclusion: Tetracosactide administration at the dosage of 1 mg intramuscularly per week for 12 months seems to be an acceptable alternative for nephrotic patients unresponsive or relapsing after steroid-immunosuppressive regimens. Further studies should be planned to assess the effect of this low-dose ACTH regimen also in nephrotic patients not eligible for kidney biopsy or immunosuppressive protocols
ACTIVIDAD CELULOLITICA DE CEPAS DE Aspergillus niger y A. flavus AISLADAS DE SUELOS CON CULTIVO DE TRIGO Y TRATAMIENTO HERBICIDA
Se estudia la actividad celulolítica de cepas de Aspergillus niger y A. flavus aisladas de suelo del sur de la provincia de Santa Fe, sembrado con trigo y tratado con Metsulfurón-metil+Dicamba. Dichas cepas fueron las más frecuentes en un muestreo que abarcó distintas etapas del cultivo de trigo en 1994 y mostraron a su vez, variaciones en su frecuencia a lo largo del mismo.Nuestro objetivo fue conocer si dichas variaciones de frecuencia se correlacionan con cambios en la actividad celulolítica de las mismas. Se trabajó con 3 cepas deA. niger y 2 de A. flavus. En los filtrados de los cultivos, se determinó: peso seco, proteínas solubles, producción de exoglucanasas frente a la celulosa cristalina, endoglucanasas frente a carboximetilcelulosa y celobiasas extracelulares.En A. niger, no hubo una correlación clara entre frecuencia y actividad enzimática, sólo se observó que las cepas de A. niger de mayor frecuencia (superior al 50%) tuvieron también mayor actividad. En A. flavus, encambio, se observó una correlación inversa
ESAF: Full Simulation of Space-Based Extensive Air Showers Detectors
Future detection of Extensive Air Showers (EAS) produced by Ultra High Energy
Cosmic Particles (UHECP) by means of space based fluorescence telescopes will
open a new window on the universe and allow cosmic ray and neutrino astronomy
at a level that is virtually impossible for ground based detectors. In this
paper we summarize the results obtained in the context of the EUSO project by
means of a detailed Monte Carlo simulation of all the physical processes
involved in the fluorescence technique, from the Extensive Air Shower
development to the instrument response. Particular emphasis is given to
modeling the light propagation in the atmosphere and the effect of clouds. Main
results on energy threshold and resolution, direction resolution and Xmax
determination are reported. Results are based on EUSO telescope design, but are
also extended to larger and more sensitive detectors.Comment: 38 pages, 48 figures Corrected typos. Changed content. Added figure
Restorative surgery after colectomy for ulcerative colitis in England and Sweden:observations from a comparison of nationwide cohorts
Spatial and Temporal Dust Source Variability in Northern China Identified Using Advanced Remote Sensing Analysis
The aim of this research is to provide a detailed characterization of spatial patterns and temporal trends in the regional and local dust source areas within the desert of the Alashan Prefecture (Inner Mongolia, China). This problem was approached through multi-scale remote sensing analysis of vegetation changes. The primary requirements for this regional analysis are high spatial and spectral resolution data, accurate spectral calibration and good temporal resolution with a suitable temporal baseline. Landsat analysis and field validation along with the low spatial resolution classifications from MODIS and AVHRR are combined to provide a reliable characterization of the different potential dust-producing sources. The representation of intra-annual and inter-annual Normalized Difference Vegetation Index (NDVI) trend to assess land cover discrimination for mapping potential dust source using MODIS and AVHRR at larger scale is enhanced by Landsat Spectral Mixing Analysis (SMA). The combined methodology is to determine the extent to which Landsat can distinguish important soils types in order to better understand how soil reflectance behaves at seasonal and inter-annual timescales. As a final result mapping soil surface properties using SMA is representative of responses of different land and soil cover previously identified by NDVI trend. The results could be used in dust emission models even if they are not reflecting aggregate formation, soil stability or particle coatings showing to be critical for accurately represent dust source over different regional and local emitting areas
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