Estimation of the cortical connectivity by high-resolution EEG and structural equation modeling: simulations and application to finger tapping data

Today, the concept of brain connectivity plays a central role in the neuroscience. While functional connectivity is defined as the temporal coherence between the activities of different brain areas, the effective connectivity is defined as the simplest brain circuit that would produce the same temporal relationship as observed experimentally between cortical sites. The most used method to estimate effective connectivity in neuroscience is the structural equation modeling (SEM), typically used on data related to the brain hemodynamic behavior. However, the use of hemodynamic measures limits the temporal resolution on which the brain process can be followed. The present research proposes the use of the SEM approach on the cortical waveforms estimated from the high-resolution EEG data, which exhibits a good spatial resolution and a higher temporal resolution than hemodynamic measures. We performed a simulation study, in which different main factors were systematically manipulated in the generation of test signals, and the errors in the estimated connectivity were evaluated by the analysis of variance (ANOVA). Such factors were the signal-to-noise ratio and the duration of the simulated cortical activity. Since SEM technique is based on the use of a model formulated on the basis of anatomical and physiological constraints, different experimental conditions were analyzed, in order to evaluate the effect of errors made in the a priori model formulation on its performances. The feasibility of the proposed approach has been shown in a human study using high-resolution EEG recordings related to finger tapping movements.     

Gene transfer of vancomycin and tetracycline resistances among Enterococcus faecalis during cheese and sausage fermentations

This study assessed the frequency of transfer of two mobile genetic elements coding for virulence determinants and antibiotic resistance factors, into food associated enterococci during fermentation processes. First, the transfer of the pheromone-inducible pCF10 plasmid, carrying tetracycline resistance and aggregation substance (AS) as virulence factor, between clinical and food strains of Enterococcus faecalis, was investigated in models of cheese and fermented sausage. The experiments demonstrated that even in the absence of selective tetracycline pressure, plasmid pCF10 was transferred from E. faecalis OG1rf cells to food strain E. faecalis BF3098c and that the plasmid subsequently persisted in these environments. Very high frequency of transfer was observed in sausage (10(-3)/recipient) if compared to cheese (10(-6)) and plate mating (10(-4)). Transconjugants were subsequently verified by PCR. The second transmissible element was the plasmid harbouring the vancomycin resistance (VanA phenotype) from E. faecalis A256. The transfer of this antibiotic resistance to a food strain of E. faecalis was studied in vitro and in food models. Although the transfer of vancomycin resistance was achieved in all the environments, the highest conjugation frequencies were observed during the ripening of fermented sausages, reaching 10(-3) transconjugants/recipient cell. PCR confirmed the transfer of the VanA genotype into a food associated Enterococcus strain. This study showed that even in the absence of selective pressure, mobile genetic elements carrying antibiotic resistance and virulence determinants can be transferred at high frequency to food associated enterococci during cheese and sausage fermentation.     

Synthesis and sintering of (Mg,Co, Ni,Cu, Zn)O entropy-stabilized oxides obtained by wet chemical methods

Entropy-stabilized oxides represent a novel family of advanced ceramic materials with attractive functional properties. In this work, entropy-stabilized oxides, in the system (Mg, Co, Ni, Cu, Zn)O, were produced by co-precipitation and hydrothermal synthesis. Although TG/DTA and XRD analyses of as-synthetized powders point out complex thermal evolution, in both cases the desired single-phase rock salt solid solution was obtained after a proper thermal treatment. The dilatometric analysis points out the excellent sinterability of the obtained powders, which were successfully consolidated for the first time reaching nearly full density (~ 97%) at relatively low temperature (1050 °C).     

Stereoselective Access to Antimelanoma Agents by Hybridization and Dimerization of Dihydroartemisinin and Artesunic acid

A library of five hybrids and six dimers of dihydroartemisinin and artesunic acid has been synthetized in a stereo-controlled manner and evaluated for the anticancer activity against metastatic melanoma cell line (RPMI7951). Among novel derivatives, three artesunic acid dimers showed antimelanoma activity and cancer selectivity, being not toxic on normal human fibroblast (C3PV) cell line. Among the three dimers, the one bearing 4-hydroxybenzyl alcohol as a spacer showed no cytotoxic effect (CC₅₀>300 μM) and high antimelanoma activity (IC₅₀=0.05 μM), which was two orders of magnitude higher than that of parent artesunic acid, and of the same order of commercial drug paclitaxel. In addition, this dimer showed cancer-type selectivity towards melanoma compared to prostate (PC3) and breast (MDA-MB-231) tumors. The occurrence of a radical mechanism was hypothesized by DFO and EPR analyses. Qualitative structure activity relationships highlighted the role of artesunic acid scaffold in the control of toxicity and antimelanoma activity.     

Fully Transparent Nanocomposite Coating with an Amorphous Alumina Matrix and Exceptional Wear and Scratch Resistance

This study presents a method for high temperature stabilization of amorphous alumina. The strain‐induced stabilization is obtained by dispersion of rigid globular polycarbosilane macromolecules within an alumina matrix. The alumina matrix remains amorphous even at 1200 °C. This study confirms the chemical composition of the coating with an advanced chemical depth‐profile analysis and shows its nanostructure by transmission electron microscopy. Based on this amorphous nanocomposite, a new facile and inexpensive coating for mechanical protection of glass surfaces is further developed. The nanocomposite coating is characterized by a full optical transparency and exceptional tribological characteristics. The wear resistance exceeds that of the current advanced ion‐exchanged boroaluminosilicate glass by a factor of 25–35 whereas its scratch resistance is exceeded by more than an order of magnitude.     

A new rigorous model for high-resolution satellite imagery orientation: application to EROS A and QuickBird

The correct georeferencing of remote sensing imagery is a fundamental task for orthoimages, digital elevation models (DEMs)/digital surface models (DSMs) generation and 3D feature/object extraction. In this article we focus on the georeferencing of pushbroom sensors imagery, in particular single images collected by EROS A and QuickBird satellites, with a rigorous model that is based on the collinearity equations. The model, implemented in the software SISAR (Software per Immagini Satellitari ad Alta Risoluzione), reconstructs the orbital segment during image acquisition through the Keplerian orbital parameters, the sensor attitude, the internal orientation and additional self-calibration parameters. With respect to the estimation procedure, in order to avoid possible instabilities due to high correlations among some parameters leading to design matrix pseudo-singularity, singular value decomposition (SVD) and QR decomposition are used to select the estimable parameters and finally to solve the extended linearized collinearity equations system in the least square (LS) sense.

To test the effectiveness of the new model, SISAR results are compared with the rigorous model implemented in the well-known commercial software OrthoEngine 10.0 (PCI Geomatics, ON, Canada). In this article six images are concerned (two from EROS A and four from QuickBird), showing that SISAR performances are at the level of the OrthoEngine ones.     

Path planning with obstacle avoidance based on visibility binary tree algorithm

In this paper, a novel method for robot navigation in dynamic environments, referred to as visibility binary tree algorithm, is introduced. To plan the path of the robot, the algorithm relies on the construction of the set of all complete paths between robot and target taking into account inner and outer visible tangents between robot and circular obstacles. The paths are then used to create a visibility binary tree on top of which an algorithm for shortest path is run. The proposed algorithm is implemented on two simulation scenarios, one of them involving global knowledge of the environment, and the other based on local knowledge of the environment. The performance are compared with three different algorithms for path planning.     

Procedural content generation for platformers: designing and testing FUN PLEdGE

Video games are a peculiar medium, standing at the crossing point between art and software application, and characterized by an active involvement of its audience. The complexity of the product generates a huge challenge for the companies that develop video games. In the development process, level designers play a crucial role: they are in charge of declining the theoretical framework developed by the game designer into game levels, which contain the actual gameplay scenarios. Hence, the final goal of any level designer is to valorize the game design by creating enjoyable gaming experiences while, at the same time, respecting several constraints. To lighten the burden on level designers, several semi-automated approaches to level generation have appeared in time, but the majority of these tools suffer from several drawbacks. In the present work, we tackle the issue of designing, prototyping and testing FUN PLEdGE, a general-purpose automated levels generator and editor for platform video games. Its main goal is to shrink development time while producing – unassisted – levels that are both playable and fun. Moreover, our tool provides the maximum freedom to the level designer, by avoiding to impose unnecessary constraints on the structure of the levels and by guaranteeing the possibility to modify and personalize by hand the generated levels. During this process, the generator assists the designer by suggesting corrections functional to the quality of the player experience. To prove the effectiveness of our prototypal application we have also developed and tested with players a platform game. In the same vein, we asked to a group of game developers to test FUN PLEdGE.