Search results for "Simulation."

An Architecture for Observational Learning

2014

In this thesis I present an architecture that learns new skills through observation and adapts to the environment through situated experience in the world. Such an architectural growth is bootstrapped from a minimal initial knowledge and the architecture itself is built around the biologically-inspired notion of internal models. The key idea, supported by findings in cognitive neuroscience, is that the same internal models used in overt goal-directed action execution can be covertly re-enacted in simulation to observe and understand the actions of others. The system applies these concepts to learning higher order cognitive functions like learning problem solving skills and social interactio…

Gene connectivity and enzyme evolution in the human metabolic network

2019

[Background] Determining the factors involved in the likelihood of a gene being under adaptive selection is still a challenging goal in Evolutionary Biology. Here, we perform an evolutionary analysis of the human metabolic genes to explore the associations between network structure and the presence and strength of natural selection in the genes whose products are involved in metabolism. Purifying and positive selection are estimated at interspecific (among mammals) and intraspecific (among human populations) levels, and the connections between enzymatic reactions are differentiated between incoming (in-degree) and outgoing (out-degree) links.

In silico methods for metabolomic and toxicity prediction of zearalenone, α-zearalenone and β-zearalenone.

2020

Zearalenone (ZEA), α-zearalenol (α-ZEL) and β-zearalenol (β-ZEL) (ZEA's metabolites) are co/present in cereals, fruits or their products. All three with other compounds, constitute a cocktail-mixture that consumers (and also animals) are exposed and never entirely evaluated, nor in vitro nor in vivo. Effect of ZEA has been correlated to endocrine disruptor alterations as well as its metabolites (α-ZEL and β-ZEL); however, toxic effects associated to metabolites generated once ingested are unknown and difficult to study. The present study defines the metabolomics profile of all three mycotoxins (ZEA, α-ZEL and β-ZEL) and explores the prediction of their toxic effects proposing an in silico w…

In situ structural analysis of SARS-CoV-2 spike reveals flexibility mediated by three hinges

2020

Flexible spikes The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein enables viral entry into host cells by binding to the angiotensin-converting enzyme 2 (ACE2) receptor and is a major target for neutralizing antibodies. About 20 to 40 spikes decorate the surface of virions. Turoňová et al. now show that the spike is flexibly connected to the viral surface by three hinges that are well protected by glycosylation sites. The flexibility imparted by these hinges may explain how multiple spikes act in concert to engage onto the flat surface of a host cell. Science, this issue p. 203

Correlation BetweenIn Vitro,In Situ, andIn Vivo Models

2008

Integrazione di celle solari di terza generazione nel vetromattone per la realizzazione di pannelli traslucidi fotovoltaici. Analisi prestazione e st…

2013

L’articolo illustra i primi risultati ottenuti nell’ambito dell’analisi prestazionale del vetromattone fotovoltaico, un prodotto edilizio innovativo derivato dall’integrazione di celle fotovoltaiche di terza generazione (DSSC) nel vetromattone, ideato per la realizzazione di involucri traslucidi energeticamente effi cienti ed “attivi”, in grado di ridurre i consumi energetici degli edifi ci e di produrre, al contempo, energia verde. L’analisi è stata condotta su quattro differenti ipotesi di integrazione. Attraverso simulazioni numeriche si è effettuata una valutazione dell’energia assorbita dagli strati attivi oltre che delle prestazioni ottiche complessive del dispositivo. Lo studio anali…

Defining level A IVIVC dissolution specifications based on individual in vitro dissolution profiles of a controlled release formulation.

2018

Regulatory guidelines recommend that, when a level A IVIVC is established, dissolution specification should be established using averaged data and the maximum difference between AUC and Cmax between the reference and test formulations cannot be greater than 20%. However, averaging data assumes a loss of information and may reflect a bias in the results. The objective of the current work is to present a new approach to establish dissolution specifications using a new methodology (individual approach) instead of average data (classical approach). Different scenarios were established based on the relationship between in vitro-in vivo dissolution rate coefficient using a level A IVIVC of a cont…

"Table 7" of "Studies of QCD in e+ e- --> hadrons at E(cm) = 130-GeV and 136-GeV."

2000

Distribution of Thrust.

Horizontal visibility graphs: exact results for random time series

2009

The visibility algorithm has been recently introduced as a mapping between time series and complex networks. This procedure allows us to apply methods of complex network theory for characterizing time series. In this work we present the horizontal visibility algorithm, a geometrically simpler and analytically solvable version of our former algorithm, focusing on the mapping of random series (series of independent identically distributed random variables). After presenting some properties of the algorithm, we present exact results on the topological properties of graphs associated with random series, namely, the degree distribution, the clustering coefficient, and the mean path length. We sh…

Multi-subject fMRI analysis via combined independent component analysis and shift-invariant canonical polyadic decomposition

2014

Canonical polyadic decomposition (CPD) may face a local optimal problem when analyzing multi-subject fMRI data with inter-subject variability. Beckmann and Smith proposed a tensor PICA approach that incorporated an independence constraint to the spatial modality by combining CPD with ICA, and alleviated the problem of inter-subject spatial map (SM) variability.This study extends tensor PICA to incorporate additional inter-subject time course (TC) variability and to connect CPD and ICA in a new way. Assuming multiple subjects share common TCs but with different time delays, we accommodate subject-dependent TC delays into the CP model based on the idea of shift-invariant CP (SCP). We use ICA …