Effects of carbonaceous nanoparticles from low-emission and older diesel engines on human skin cells

Diesel exhaust particles (DEP) are major constituents of ambient air pollution and are associated with respiratory and cardiovascular diseases as well skin cell alterations in vitro. The epidermal cells are among the first cell populations exposed to chemical pollutants, including DEP, and are an important source of pro-inflammatory mediators. We evaluated the effects of carbonaceous soot particles from current low-emission (Euro IV) diesel engines on the oxidative and inflammatory response of normal human skin cells and compared the results with those induced by carbonaceous soot particles from an older diesel engine (BS) operating under black smoke conditions. We observed that both soot nanoparticles were spontaneously internalised by keratinocytes and distributed mostly around the cell nucleus. Moreover, at the same mass concentration, Euro IV soot particles exhibited a much higher oxidative, pro-fibrotic and toxic potential on these cell types than soot particles from the older diesel engine. These results are in agreement with and confirm our previous findings on human macrophage cells and strengthen the assumption that, at the same mass concentration, soot particles produced under low emission conditions are more cytotoxic than particles from the older diesel engine. This effect could be assigned to the defective surface structure of Euro IV diesel soot, rendering it highly active. Our findings highlight that the reduction of soot emission in terms of mass does not automatically lead to a reduction of the dangerous effects and show that soot particles from different diesel engines possess different biological behaviour towards human cells.     

A survey of grammatical inference methods for natural language learning

The high complexity of natural language and the huge amount of human and temporal resources necessary for producing the grammars lead several researchers in the area of Natural Language Processing to investigate various solutions for automating grammar generation and updating processes. Many algorithms for Context-Free Grammar inference have been developed in the literature. This paper provides a survey of the methodologies for inferring context-free grammars from examples, developed by researchers in the last decade. After introducing some preliminary definitions and notations concerning learning and inductive inference, some of the most relevant existing grammatical inference methods for Natural Language are described and classified according to the kind of presentation (if text or informant) and the type of information (if supervised, unsupervised, or semi-supervised). Moreover, the state of the art of the strategies for evaluation and comparison of different grammar inference methods is presented. The goal of the paper is to provide a reader with introduction to major concepts and current approaches in Natural Language Learning research.     

Characterization of Fiore Sardo cheese manufactured with the addition of autochthonous cultures

This work evaluated the effect of adjunct autochthonous cultures on the chemical, microbiological and sensory characteristics of Fiore Sardo cheese during ripening. A total of twelve batches of cheeses were manufactured according to the technical Disciplinary of Fiore Sardo cheese, with and without different combinations of autochthonous strains isolated from the native microflora of artisanal Fiore Sardo. There were no significant differences in the cheese compositional parameters between experimental and control cheeses, but the addition of cultures led to a statistically significant decrease in pH values in experimental cheeses. The evolution of total mesophilic bacteria, total coliforms and lactic acid bacteria were significantly influenced by the addition of autochthonous cultures in most of the experimental cheeses. As for sensory characteristics, all the experimental cheeses reported significantly higher scores especially for shape, texture, interior openings, taste and aftertaste. This study demonstrated the beneficial effect of the addition of selected autochthonous cultures in accelerating the disappearance of undesirable flora and improving the typical sensory characteristics of the cheese, and confirmed the importance of ewes' milk as a source of technologically interesting strains that could be used to ensure a higher quality of artisanal cheese productions.     

Dynamics and mechanisms of interfacial photoinduced electron transfer processes of third generation photovoltaics and photocatalysis

Photoinduced electron transfer (PET) across molecular/bulk interfaces has gained attention only recently and is still poorly understood. These interfaces offer an excellent case study, pertinent to a variety of photovoltaic systems, photo- and electrochemistry, molecular electronics, analytical detection, photography, and quantum confinement devices. They play in particular a key role in the emerging fields of third-generation photovoltaic energy converters and artificial photosynthetic systems aimed at the production of solar fuels, creating a need for a better understanding and theoretical treatment of the dynamics and mechanisms of interfacial PET processes. We aim to achieve a fundamental understanding of these phenomena by designing experiments that can be used to test and alter modern theory and computational modeling. One example illustrating recent investigations into the details of the ultrafast processes that form the basis for photoinduced charge separation at a molecular/bulk interface relevant to dye-sensitized solar cells is briefly presented here: Kinetics of interfacial PET and charge recombination processes were measured by fs and ns transient spectroscopy in a heterogeneous donor-bridge-acceptor (D-B-A) system, where D is a Ru(II)(terpyridyl-PO3)(NCS)3 complex, B an oligo-p-phenylene bridge, and A nanocrystalline TiO2. The forward ET reaction was found to be faster than vibrational relaxation of the vibronic excited state of the donor. Instead, the back ET occurred on the micros time scale and involved fully thermalized species. The D-A distance dependence of the electron transfer rate was studied by varying the number of p-phenylene units contained in the bridge moiety. The remarkably low damping factor beta = 0.16 angstroms(-1) observed for the ultrafast charge injection from the dye excited state into the conduction band of TiO2 is attributed to the coupling of electron tunneling with nonequilibrium vibrations redistributed on the bridge, giving rise to polaronic transport of charges from the donor ligand to the acceptor solid oxide surface.     

Grid_strain and grid_strain3: Software packages for strain field computation in 2D and 3D environments

Two Matlab™ software packages for strain field computation, starting from displacements of experimental points (EPs), are here presented. In particular, grid_strain estimates the strain on the nodes of a regular planar grid, whereas grid_strain3 operates on the points of a digital terrain model (DTM). In both cases, the computations are performed in a modified least-square approach, emphasizing the effects of nearest points. This approach allows users to operate at different scales of analysis by introducing a scale factor to reduce or also exclude points too far from grid nodes. The input data are displacements (or velocities) that can be provided by several techniques (e.g. GPS, total topographical station, terrestrial laser scanner). The analysis can be applied to both regional- and local-scale phenomena, to study tectonic crustal deformations (strain ≈10⁻⁸−10⁻⁶) or rapid landslide collapses (10⁻⁴−10²), and to characterize the kinematics of the studied system. Errors on strains and geometric significance of the results are also provided.     

Does Virtual Reality Enhance the Management of Stress When Paired With Exercise? An Exploratory Study.

The purpose of the present study was to assess the psychological benefits of virtual reality paired with aerobic exercise in a laboratory setting. In this study, 154 introductory psychology students were randomly assigned to 1 of 4 20-min conditions (a) walking outside around campus, (b) walking on a laboratory treadmill combined with virtual reality to experience both virtual and actual exercise, (c) walking on the laboratory treadmill without virtual reality, and (d) experiencing a virtual walk with virtual reality without actual exercise. Our results suggest that virtual reality may enhance some of the psychological benefits of exercise when paired with actual exercise under certain conditions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Criticality of the measurement of corneal thickness in specular reflection by digital biomicroscope

Purpose

The aim was to evaluate the effects on corneal thickness (t) measurement, of asymmetry of the CCD position for a digital biomicroscope in specular reflection.