794 research outputs found
Gutierrezia mendocina (Asteraceae, Astereae), una nueva especie sudamericana
A taxonomic revision of the South American species of Gutierrezia has revealed a new species from Argentina, characterised by its stems with the base prostrate and rooting, turbinate heads and white ray florets. This species, found in the Department of Tunuyán of Mendoza Province (Argentina), is described and illustrated and a key to differentiate it from allied species is given.En el marco de la revisión taxonómica del género Gutierrezia para Sudamérica fue hallada una nueva especie de Argentina, caracterizada por sus tallos con la porción basal postrada, enraizante en los nudos, capítulos con involucro turbinado y flores liguladas blancas. Se describe e ilustra la especie encontrada en el Departamento de Tunuyán de la Provincia de Mendoza (Argentina), y se incluye una clave para diferenciarla de las especies afines
The October 2000 flooding in Valle d'Aosta (Italy): Event description and land planning measures for the risk mitigation
On October 13-16th, 2000 heavy rainfalls in the Northwestern Italian Alps caused huge flooding and landslides with significant damages to houses and infrastructures and several life losses. In this paper a description of the main events that affected Valle d’Aosta’s region and the subsequent land planning measures adopted for the risk mitigation are presented. After a first meteorological and hydrological framing, based on the data of the regional monitoring system (that pointed out rainfalls up to 236 mm in 24 h also in high‐altitude zones, because of the rise of the isotherm 0°C around 3000 m above sea level), the main effects of the event (extensive flooding, landslides, soil slips and debris flows) in the regional catchment of the Dora Baltea river are described. Through aerial and direct surveys those effects have been transferred into a thematic cartography within two months from the event, in order to have detailed elements for the technical, administrative and political land planning decisions, and, on this basis, a new regional directive containing detailed measures for the hydro‐geological risk mitigation and land safety has been adopted. © 2003 by Taylor nad Francis Group, LLC
Tipificación en Gutierrezia (Asteraceae, Astereae)
During the course of the revision of the South American species of Gutierrezia, we have detected names that require typification. After the analysis of the protologues and the herbarium specimens, we designated eight lectotypes and one neotype for nine names of the Gutierrezia genus and we assigned the category of holotype to one specimen. A detailed discussion is provided for each case.Durante el transcurso de la revisión de las especies sudamericanas de Gutierrezia, hemos podido hallar nombres que requieren tipificación. Luego del análisis de los protologos y especímenes de herbario, hemos designado ocho lectótipos y un neótipo para nueve nombres del género Gutierrezia. Además, se asignó la categoría de hólotipo a un especimen. Se provee una discusión detallada para cada nombre
Comparison between the results of a new version of the AVACTA II atmospheric diffusion model and tracer experiments
A new version of the AVACTA II code (a code recommended by EPA) has been implemented and evaluated. AVACTA II is a code based on a mixed segmentpuff approach, which allows numerical simulations of both non-stationary and nonhomogeneous conditions. In our version, the wind field is calculated through the 3D mass-consistent code WINDS developed at the Department of Physics of the University
of Genoa, Italy. The model evaluation of this new version of the AVACTA II code has been performed using field experiment data on flat, but rough, terrain (Karlsruhe
Nuclear Research Center (KNRC) tracer experiments) and wind tunnel measurements(EPA Rushil experiments) both in flat and complex terrain. A comparison is made between
simulated and measured concentration distributions. The results of these evaluations are very encouraging
Uncertainty, sensitivity analysis and the role of data based mechanistic modeling in hydrology
International audienceIn this paper, we discuss the problem of calibration and uncertainty estimation for hydrologic systems from two points of view: a bottom-up, reductionist approach; and a top-down, data-based mechanistic (DBM) approach. The two approaches are applied to the modelling of the River Hodder catchment in North-West England. The bottom-up approach is developed using the TOPMODEL, whose structure is evaluated by global sensitivity analysis (GSA) in order to specify the most sensitive and important parameters; and the subsequent exercises in calibration and validation are carried out in the light of this sensitivity analysis. GSA helps to improve the calibration of hydrological models, making their properties more transparent and highlighting mis-specification problems. The DBM model provides a quick and efficient analysis of the rainfall-flow data, revealing important characteristics of the catchment-scale response, such as the nature of the effective rainfall nonlinearity and the partitioning of the effective rainfall into different flow pathways. TOPMODEL calibration takes more time and it explains the flow data a little less well than the DBM model. The main differences in the modelling results are in the nature of the models and the flow decomposition they suggest. The "quick'' (63%) and "slow'' (37%) components of the decomposed flow identified in the DBM model show a clear partitioning of the flow, with the quick component apparently accounting for the effects of surface and near surface processes; and the slow component arising from the displacement of groundwater into the river channel (base flow). On the other hand, the two output flow components in TOPMODEL have a different physical interpretation, with a single flow component (95%) accounting for both slow (subsurface) and fast (surface) dynamics, while the other, very small component (5%) is interpreted as an instantaneous surface runoff generated by rainfall falling on areas of saturated soil. The results of the exercise show that the two modelling methodologies have good synergy; combining well to produce a complete modelling approach that has the kinds of checks-and-balances required in practical data-based modelling of rainfall-flow systems. Such a combined approach also produces models that are suitable for different kinds of application. As such, the DBM model can provides an immediate vehicle for flow and flood forecasting; while TOPMODEL, suitably calibrated (and perhaps modified) in the light of the DBM and GSA results, immediately provides a simulation model with a variety of potential applications, in areas such as catchment management and planning
Quantitative readout of optically encoded gold nanorods using an ordinary dark-field microscope.
Quantitative analysis of basic fibroblast growth factor and vascular endothelial growth factor in human colorectal cancer.
Tumour growth is angiogenesis dependent. Some authors suggest a prognostic role of microvessel count in colorectal cancer. We tested the role of basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF) in the switch to the angiogenic phenotype in 35 patients with colorectal cancer at different stages of disease. We evaluated the two angiogenic factors, by enzyme-linked immunosorbent assay (ELISA), in tumour, peritumoral mucosa, pathological mesenteric and peripheral blood. We used ten endoscopic intestinal biopsies and ten peripheral blood samples from healthy subjects as control. bFGF was significantly lower in tumour tissues and in peritumoral mucosas than in healthy mucosas, whereas VEGF was up-regulated in tumours but not in peritumoral mucosa. Both angiogenic factors were greatly increased in mesenteric blood. VEGF tumour and serum levels were significantly correlated with the stage of disease. bFGF tumour and serum concentration were not correlated with the stage of disease. The high levels of bFGF in mesenteric blood suggest that this growth factor might be abnormally released from tumour tissue and peritumoral mucosa and could function as an early effector in the switch to the angiogenic phenotype. In contrast, VEGF, whose levels show a significant correlation with the stage of disease, could act in a following step, supporting tumour progression
Combining polynomial chaos expansions and genetic algorithm for the coupling of electrophysiological models
The number of computational models in cardiac research has grown over the last decades. Every year new models with di erent assumptions appear in the literature dealing with di erences in interspecies cardiac properties. Generally, these new models update the physiological knowledge using new equations which reect better the molecular basis of process. New equations require the fi tting of parameters to previously known experimental data or even, in some cases, simulated data. This work studies and proposes a new method of parameter adjustment based on Polynomial Chaos and Genetic Algorithm to nd the best values for the parameters upon changes in the formulation of ionic channels. It minimizes the search space and the computational cost combining it with a Sensitivity Analysis. We use the analysis of di ferent models of L-type calcium channels to see that by reducing the number of parameters, the quality of the Genetic Algorithm dramatically improves. In addition, we test whether the use of the Polynomial Chaos Expansions improves the process of the Genetic Algorithm search. We conclude that it reduces the Genetic Algorithm execution in an order of 103 times in the case studied here, maintaining the quality of the results. We conclude that polynomial chaos expansions can improve and reduce the cost of parameter adjustment in the development of new models.Peer ReviewedPostprint (author's final draft
Torino, via Maria Vittoria 7c. Oratorio di S. Filippo Neri. Strutture di età romana e impianti ottocenteschi
Nell'ambito del cantiere archeologico che ha interessato l'Isolato S. Filippo in Torino, prestigiosa isola che comprende la nota omonima chiesa con oratorio, sono state rinvenute strutture che, a fronte di indagini bibliografiche e di archivio, sono state identificate come segni di impianti utili al fabbricato prospiciente via Carlo Alberto, nell'Ottocento sede centrale delle Poste e Telegrafi e del Ministero dei Lavori pubblici. Raro riferimento per una cosiddetta "storia dell'impiantistica", il testo, oltre a introdurre le principali vicende che hanno accompagnato le trasformazioni del luogo, propone una disamina dettagliata dei materiali ritrovati
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