Search results for "Models"
showing 10 items of 8211 documents
Emulation of Leaf, Canopy and Atmosphere Radiative Transfer Models for Fast Global Sensitivity Analysis
2016
Physically-based radiative transfer models (RTMs) help understand the interactions of radiation with vegetation and atmosphere. However, advanced RTMs can be computationally burdensome, which makes them impractical in many real applications, especially when many state conditions and model couplings need to be studied. To overcome this problem, it is proposed to substitute RTMs through surrogate meta-models also named emulators. Emulators approximate the functioning of RTMs through statistical learning regression methods, and can open many new applications because of their computational efficiency and outstanding accuracy. Emulators allow fast global sensitivity analysis (GSA) studies on adv…
Towards the ultimate minimum particle diameter of silica packings in capillary electrochromatography.
2000
Porous silica beads with an average particle diameter between 0.2 and 3 microm have been applied as packing material in capillary electrochromatography (CEC). The experiments were directed to investigate whether it is really feasible and as promising as expected to use such small particles. In CEC, plate heights of H approximately/= 1-2 d(p) can be achieved which is smaller than the plate heights usually attained in high-performance liquid chromatography. Using a capillary packed with 0.5 microm silica beads we achieved a plate height of H = 3 d(p) indicating the presence of dispersive effects like Joule heating. Calculations demonstrate that at a field strength of about 800 V cm(-1) one th…
RpeakChrom: Novel R package for the automated characterization and optimization of column efficiency in high-performance liquid chromatography analys…
2017
Characterization of chromatographic columns using the traditional van Deemter method is limited by the necessity of calculating extra-column variance, issue particularly relevant when modeling asymmetrical peaks eluted from monolithic columns. A novel R package that implements Parabolic Variance Modified Gaussian approach for accurate peak modeling, van Deemter equation and two alternatives approaches, based on van Deemter, has been developed to calculate the height equivalent to a theoretical plate (HETP). To assess package capabilities conventional packed reverse-phase and monolithic HPLC columns were characterized. Peaks eluted from the monolithic column showed a high value of factor asy…
Perspective on Curved Surfaces in the Age of Pozzo: The Nuova Pratica di Prospettiva of Paolo Amato
2016
The study focuses an almost unknown treatise on perspective, The Nuova Pratica di Prospettiva, written by the priest Paolo Amato (1634–1714) in the last years of his life and published posthumously in 1733. The main points of interest of the Nuova Pratica is the perspective projection on cylindrical surfaces, which exceeds the coeval ‘practical’ treatises on perspective. A detailed resume of Amato’s treatise is accompanied by geometric schemes illustrating the perspective method proposed by the author. None of the paintings made by Amato has come down to us, but the vault covering a hall added to a Norman church in Palermo shows a trompe l’oeil that was painted by one of his favorite discip…
Palermo tra innesti e piante originarie
2019
Se vi è qualcosa di profondamente e visceralmente connaturato alla stessa dimensione esistenziale della città di Palermo, sin dalle sue molteplici e stratificate origini fenicio-puniche, questo è certamente il concetto di “innesto”. Ed in analogia con l’innesto agrario, cioè con la pratica del far concrescere in una pianta esistente una parte di un altro vegetale, al fine di rafforzare il primo soggetto ma modificandolo verso un genere diverso da quello iniziale, l’intera storia millenaria della città potrà essere riguardata come il frutto di continue, cicliche introduzioni di modelli architettonici e urbani esogeni, declinati rispetto alle contingenze culturali autoctone dei diversi esempi…
Myoglobin, expressed in brown adipose tissue of mice, regulates the content and activity of mitochondria and lipid droplets
2021
Abstract The identification of novel physiological regulators that stimulate energy expenditure through brown adipose tissue (BAT) activity in substrate catalysis is of utmost importance to understand and treat metabolic diseases. Myoglobin (MB), known to store or transport oxygen in heart and skeletal muscles, has recently been found to bind fatty acids with physiological constants in its oxygenated form (i.e., MBO2). Here, we investigated the in vivo effect of MB expression on BAT activity. In particular, we studied mitochondrial function and lipid metabolism as essential determinants of energy expenditure in this tissue. We show in a MB-null (MBko) mouse model that MB expression in BAT i…
Predominant pathogenic role of tumor necrosis factor in experimental colitis in mice
1997
Antibodies to tumor necrosis factor (TNF)-alpha have been recently proposed as effective treatment for patients with Crohn's disease. Here, we analyze the functional role of TNF-alpha in a mouse model of chronic intestinal inflammation induced by the hapten reagent 2,4,6,-trinitrobenzene sulfonic acid (TNBS) that mimics some characteristics of Crohn's disease in humans. Macrophage-enriched lamina propria (LP) mononuclear cells from mice with TNBS-induced colitis produced 10-30-fold higher levels of TNF-alpha mRNA and protein than cells from control mice. When mice with chronic colitis were treated by intraperitoneal injection of antibodies to TNF-alpha, an improvement of both the clinical a…
The euro impact on trade: long run evidence with structural breaks
2012
In this paper we present new evidence on the euro effect on trade. We use a data set containing all bilateral combinations in a panel of 26 OECD countries during the period 1967-2008. From a methodological point of view, we implement a new generation of tests that allow solving some of the problems derived from the non-stationary nature of the data. To this aim we apply panel tests that account for the presence of cross-section dependence as well as discontinuities in the non-stationary panel data. We test for cointegration between the variables using panel cointegration tests, especially the ones proposed by Banerjee and Carrióni- Silvestre (2010). We also efficiently estimate the long-run…
Dynamics of real labour productivity and real compensation in Latvia
2019
Relationship between labour productivity and wages is an important issue not only for economists, but also for policy makers. In the last decades, we have witnessed that in the EU15 wage growth has been lagging productivity growth. At the same time in Latvia, also in some other central and eastern European member states, wages increased more than productivity, rising concerns about disbalance in the economy. However, comparison of wage level and productivity level in Latvia and respective levels in the EU15 shows that wage level in Latvia is much below the EU15 average value in absolute terms, but also in relation to productivity level. To understand whether dissimilarities in wage and prod…
An enhanced memetic differential evolution in filter design for defect detection in paper production.
2008
This article proposes an Enhanced Memetic Differential Evolution (EMDE) for designing digital filters which aim at detecting defects of the paper produced during an industrial process. Defect detection is handled by means of two Gabor filters and their design is performed by the EMDE. The EMDE is a novel adaptive evolutionary algorithm which combines the powerful explorative features of Differential Evolution with the exploitative features of three local search algorithms employing different pivot rules and neighborhood generating functions. These local search algorithms are the Hooke Jeeves Algorithm, a Stochastic Local Search, and Simulated Annealing. The local search algorithms are adap…