Search results for "level"
showing 10 items of 3465 documents
Robustness Analysis of DCE-MRI-Derived Radiomic Features in Breast Masses: Assessing Quantization Levels and Segmentation Agreement
2022
Featured Application The use of highly robust radiomic features is fundamental to reduce intrinsic dependencies and to provide reliable predictive models. This work presents a study on breast tumor DCE-MRI considering the radiomic feature robustness against the quantization settings and segmentation methods. Machine learning models based on radiomic features allow us to obtain biomarkers that are capable of modeling the disease and that are able to support the clinical routine. Recent studies have shown that it is fundamental that the computed features are robust and reproducible. Although several initiatives to standardize the definition and extraction process of biomarkers are ongoing, th…
First multiphoton tomography of brain in man
2016
We report on the first two-photon in vivo brain tissue imaging study in man. High resolution in vivo histology by multiphoton tomography (MPT) including two-photon FLIM was performed in the operation theatre during neurosurgery to evaluate the feasibility to detect label-free tumor borders with subcellular resolution. This feasibility study demonstrates, that MPT has the potential to identify tumor borders on a cellular level in nearly real-time.
Interaction-induced spin polarization in quantum dots.
2010
The electronic states of lateral many electron quantum dots in high magnetic fields are analyzed in terms of energy and spin. In a regime with two Landau levels in the dot, several Coulomb blockade peaks are measured. A zig-zag pattern is found as it is known from the Fock-Darwin spectrum. However, only data from Landau level 0 show the typical spin-induced bimodality, whereas features from Landau level 1 cannot be explained with the Fock-Darwin picture. Instead, by including the interaction effects within spin-density-functional theory a good agreement between experiment and theory is obtained. The absence of bimodality on Landau level 1 is found to be due to strong spin polarization.
Trophic transfer of polychlorinated biphenyls (PCB) in a boreal lake ecosystem: Testing of bioaccumulation models
2013
Understanding the fate of persistent organic chemicals in the environment is fundamental information for the successful protection of ecosystems and humans. A common dilemma in risk assessment is that monitoring data reveals contaminant concentrations in wildlife, while the source concentrations, route of uptake and acceptable source concentrations remain unsolved. To overcome this problem, different models have been developed in order to obtain more precise risk estimates for the food webs. However, there is still an urgent need for studies combining modelled and measured data in order to verify the functionality of the models. Studies utilising field-collected data covering entire food we…
A multivariate analysis of phytoplankton and food web changes in a shallow biomanipulated lake
1996
1. Phytoplankton dynamics, food chain changes and resilience in Lake Zwemlust, a shallow lake in The Netherlands, are described for the period 1986-94. 2. After biomanipulation in 1987, the lake moved through two alternative states, while the external nutrient loadings were maintained. A clear-water phase, mostly dominated by macrophytes, persisted from 1987 to 1991, and a rather turbid state, dominated by algae, occurred in the summers of 1992-94, after several consecutive and sustained perturbations affecting different parts of the food web in the lake. These two periods were characterized by different community structures. 3. The phytoplankton assemblage gradually changed in a pattern th…
No evidence of trophic cascades in an experimental microbial-based soil food web
1998
Trophic-dynamic theories predict the biomass and productivity of trophic levels to be partially top-down regulated in food webs, and that the top-down regulation will manifest itself as cascading trophic interactions. We tested the two principal predictions deduced from these theories: trophic cascades of (1) biomass regulation and (2) productivity regulation occur in food webs. We created three food webs with either one, two, or three trophic levels in soil microcosms containing a sterilized mixture of leaf litter and humus. Twenty species of bacteria and fungi formed the first trophic level, a bacterivorous nematode (Caenorhabditis elegans) and a fungivorous nematode (Aphelenchoides sp.) …
Mechanisms of protein expression in the rat optic nerve: Modifications by alcohol exposure
2005
espanolObjetivos: Nuestros trabajos previos han demostrado que el consumo abusivo de etanol durante la gestacion induce retraso en el desarrollo y alteraciones estructurales en los ojos y en la vision (Pinazo-Duran et al., Teratology 93; Eur J Ophthalmol 97; Stromland and Pinazo-Duran, Teratology 94; Alcohol Alcoholism 02). Nos proponemos estudiar a un nivel celular y molecular si el etanol modifica la expresion de proteinas marcadoras del desarrollo glial durante los estadios pre- y postnatal de la rata, que puedan contribuir a la dismorfogenesis del nervio optico. Metodo: Para estudiar las acciones del etanol sobre el desarrollo del nervio optico de ratas sometidas a un proceso de alc…
ISO 14470:2011 and EU legislative background on food irradiation technology: The Italian attitude
2014
Our work aim is to produce an overview of food irradiation technology at European Union level, with a focus on the Italian context, by specifying the legislative background, detection methods and labelling obligations. We highlight how consumers are too often misinformed about this technology and its benefits. For this purpose, a series of tools aimed at improving the amount of information have been proposed, allowing the consumer to make a free choice about whether or not to buy irradiated food based on the correct information received, independent from socio-economic factors. Finally, we show the common effort at EU and International level, represented by the ISO 14470:2011 quality standa…
Impact Acceleration During Prolonged Running While Wearing Conventional Versus Minimalist Shoes.
2020
Purpose: In recent years a sub-group of minimalist runners have emerged who aim to perform physical exercise more naturally in an attempt to reduce running-related injuries. Here we aimed to determine the effect that running with minimalist footwear in a prolonged run has on footimpact accelerations. Method: Seventeen runners ran with minimalist and conventional shoes (MS and CS, respectively) in two separate sessions; the participants had experience with both footwear types. We measured the length and frequency of each stride, as well as the tibial and head impact acceleration every 5 minutes during a prolonged run (30 minutes at 80% of each individual's maximum aerobic speed). Results: Th…
The Decline of the Spanish Fury
2015
Before the Spanish national team won the UEFA Euro 2008 tournament, it had been said that the economic take-off and growing international relevance acquired by Spanish society since the restoration of democracy after the death of General Franco had not been reflected in Spanish football. Its main representative, the Spanish national football team did not manage to obtain significant victories in the most important international championships or develop a playing style that satisfied its followers. This fact strongly contrasted with the protagonist role and huge success achieved by the main Spanish football clubs at the European level. However, the victory of the Spanish national team in Eur…