469 research outputs found

    Photoelectrocatalytic performances of nanostructured/decorated TiO 2 electrodes: Effect of wavelength and cell configuration

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    The behaviour of TiO2 based electrodes was investigated during the photoelectrocatalytic water splitting process. TiO2 nanotubes and compact oxide structures were obtained by electrochemical oxidation of Ti foils. A subsequent hydrothermal process carried out at both the nanotubular and compact oxide structures allowed decorating the structure by TiO2 nanoparticles. The synthesized TiO2 samples worked as photoanodes both in a bulk three electrode cell and in a thin gap cell. The results from measurements of the photocurrent and from electrochemical impedance spectroscopy were used to highlight a combined effect of the wavelength of the incident light and the kind of cell configuration, on the global performance of the systems. The results indicate that the decoration process does not result only in a simple increase of the specific surface, but it also determines a different concentration of the bulk and superficial sites in the electrode. The different response of the sites at different wavelengths, along with the accessibility of the electrolyte to the porous structure are evocated to justify the experimental behaviour observed

    What's about the Calibration between Confidence and Accuracy? Findings in Probabilistic Problems from Italy and Spain.

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    This paper reports some experiments on probabilistic reasoning designed to investigate the impact of the probabilistic problem presentation format (verbal-numerical and graphical-pictorial) on subjects' confidence in the correctness of their performance, other than the calibration between confidence and accuracy. To understand the potential effect of the format, these dimensions were assessed by monitoring contextual and individual variables: time pressure, numerical and visuospatial abilities, statistical anxiety and attitudes towards statistics. The participants included 257 Psychology students without statistical knowledge, recruited from Italian and Spanish universities, who fulfilled self-report validated measures. The students expressed their retrospective judgments of confidence item-by-item in relation to each probabilistic problem. This approach enabled the computation of two measures of calibration (the Bias Index - the Confidence-Judgment Accuracy Quotient). The results indicated that the problem presentation format did not exert a significant main effect on confidence, with the exception of when the interaction between the format and one subscale of the attitudes towards the statistics test was considered. The Bias Index, however, was significantly related to the interaction between format and time pressure. The study offers a point of reflection in relation to the potential effect exerted by the problem format and time constraint in calibration

    The use of distance learning and e-learning in students with learning disabilities: A review on the effects and some hint of analysis on the use during covid-19 outbreak

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    Even if the use of distance learning and E-learning has a long tradition all over the world and both have been used to keep in contact with students and to provide lessons, support and learning materials, there is an open debate on the balance between advantages and disadvantages in the use of distance learning. This debate is even more central in their use to support students with Learning Disabilities (LDs), an overarching group of neurodevelopmental disorders that affect more than 5% of students. The current COVID-19 outbreak caused school closures and the massive use of E-learning all over the world and it put higher attention on the debate of the effects of E-learning. This paper aims to review papers that investigated the positive and negative effects of the use of Distance Learning and E-learning in students with LDs. We conducted a literature review on the relationship between Distance Learning, E-learning and Learning Disabilities, via Scopus, Eric and Google Scholar electronic database, according to Prisma Guidelines. The findings are summarized using a narrative, but systematic, approach. According to the data resulting from the papers, we also discuss issues to be analyzed in future research and in the use of E-learning during the current pandemic of COVID-19

    Skin rash and response to cetuximab treatment: a retrospective single-center analysis

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    Background: The standard of care for patients with recurrent/metastatic head and neck squamous cell cancer (R/M HNSCC) not susceptible for surgery or reirradiation is chemotherapy with 5-FU and cisplatin plus cetuximab. Skin rash (SR) is a common adverse event of cetuximab. In patients treated with cetuximab for colorectal cancer there is strong evidence of a better outcome in those who undergo moderate or high grade of SR, and some retrospective data seem to confirm this finding in HNSCC. We report our experience. Materials and methods: We retrospectively reviewed 107 patients treated with cetuximab for R/M HNSCC from January 2014 to December 2016. Patients were divided in two groups by the grade of SR (G0-1 and G2-4), conforming to Common Terminology Criteria for Adverse Events (CTCAE) v 4.0. Progression-free survival (PFS) was computed as time of progression or death since the date of assessment of recurrent/metastatic disease. Overall response rate (ORR) was computed as the sum of partial and complete responses and evaluated according to RECIST 1.1. PFS and ORR were correlated to the grade of rash. Results: 67 patients were evaluable for PFS: among them PFS was significantly longer (p 0.0014) in those who underwent a G2-4 rash (9,3 months) vs G0-1 (4,9 months). Hazard Ratio was 2,445 (CI 1.412-4.232). 95 patients were evaluable for ORR: among them G0-1 group had 4,2%, while G2-4 group had 36,8% of ORR. Conclusions: Our results support data of literature on improved outcome according to the development of skin rash in HNSCC. SR might be considered a predictive marker of response in these patients; nonetheless further ad hoc studies would be interesting

    Identifying Ly{\alpha} emitter candidates with Random Forest: learning from galaxies in CANDELS survey

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    The physical processes which make a galaxy a Lyman Alpha Emitter have been extensively studied for the past 25 years. However, the correlations between physical and morphological properties of galaxies and the strength of the Lyα\alpha emission line are still highly debated. Therefore, we investigate the correlations between the rest-frame Lyα\alpha equivalent width and stellar mass, star formation rate, dust reddening, metallicity, age, half-light semi-major axis, S\'ersic index and projected axis ratio in a sample of 1578 galaxies in the redshift range 2z7.92 \leq z \leq 7.9 from the GOODS-S, UDS and COSMOS fields. From the large sample of Lyα\alpha emitters (LAEs) in the dataset we find that LAEs are typically common main sequence star forming galaxies which show stellar mass 109M \leq 10^9 \text{M}_{\odot}, star formation rate 100.5M/yr \leq 10^{0.5} \text{M}_{\odot}/\text{yr}, E(BV)0.2E(B-V) \leq 0.2 and half-light semi-major axis 1kpc\leq 1 \text{kpc}. Building on these findings we develop a new method based on Random Forest (i.e. a Machine Learning classifier) in order to select galaxies which have the highest probability of being Lyα\alpha emitters. When applied to a population in the redshift range z[2.5,4.5]z \in [2.5, 4.5], our classifier holds a (80±2)%(80 \pm 2)\% accuracy and (73±4)%(73 \pm 4)\% precision. At higher redshifts (z[4.5,6]z \in [4.5, 6]), we obtain a 73%73\% accuracy and a 80%80\% precision. These results highlight it is possible to overcome the current limitations in assembling large samples of LAEs by making informed predictions that can be used for planning future large scale spectroscopic surveys.Comment: Accepted for publication in the 4. Extragalactic astronomy section of Astronomy & Astrophysics, 13 pages, 13 figure

    Pulmonary function and CT scan imaging at low-level occupational exposureto asbestos

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    Background: In spite of the reduced exposure level, and its ban in numerous countries, compensation claims for asbestos-related diseases are far from decreasing. Methods: We used retrospective exposure assessment techniques to explore respiratory function and a computerized tomography (CT) scan in relation to past asbestos exposure in 115 male workers retired from an acrylic and polyester fiber plant. Based, on detailed information on exposure circumstances, we reconstructed a cumulative exposure estimate for each patient. Results: Time-weighted average exposure in our study population was 0.24 fibers/ml (95% confidence inteval (CI) 0.19–0.29), and the average cumulative exposure was 4.51 fibers/mL-years (95% CI 3.95–5.07). Exposure was elevated among maintenance workers, compared to other jobs (p = 0.00001). Respiratory function parameters did not vary in relation to the exposure estimates, nor to CT scan results. Risk of interstitial fibrosis showed a significant upward trend (Wald test for trend = 2.62, p = 0.009) with cumulative exposure to asbestos; risk associated with 5.26 fibers/mL-years or more, was 8-fold (95% CI 1.18–54.5). Conclusions: Our results suggest that a CT scan can detect pleuro-parenchymal lung alterations at asbestos exposure levels lower than previously thought, in absence of respiratory impairment. Further studies are required to validate our techniques of retrospective assessment of asbestos exposure

    Effect of ripening stage at harvest, cold storage, and simulated marketing conditions on quality and antioxidant activity of peach fruit

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    The influence of storage time on different quality parameters and in vitro antioxidant activity of peaches cv. Elegant Lady harvested at two ripening stages (immature and commercial mature) and stored under cold and marketing conditions were assessed. Destructive (physical-chemical properties, antioxidant activity, and firmness) and non-destructive parameters (colour and index of absorbance difference, IAD) were assessed. Storage and ripening stage influenced firmness, colour, and antioxidant activity. Firmness decreased significantly during cold and marketing storage, and skin colour parameters, a* and b*, underwent a deepening of the red hue, while IAD values fully justified differences in colour over storage time and ripening stage. The antioxidant activity increased during storage, although polyphenols and ascorbic acid contents remained constant, and was higher in commercial mature fruit than immature peaches, that revealed a ratio of total sugars/total acids more equilibrated

    Spatially Explicit Data: Stewardship and Ethical Challenges in Science

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    Scholarly communication is at an unprecedented turning point created in part by the increasing saliency of data stewardship and data sharing. Formal data management plans represent a new emphasis in research, enabling access to data at higher volumes and more quickly, and the potential for replication and augmentation of existing research. Data sharing has recently transformed the practice, scope, content, and applicability of research in several disciplines, in particular in relation to spatially specific data. This lends exciting potentiality, but the most effective ways in which to implement such changes, particularly for disciplines involving human subjects and other sensitive information, demand consideration. Data management plans, stewardship, and sharing, impart distinctive technical, sociological, and ethical challenges that remain to be adequately identified and remedied. Here, we consider these and propose potential solutions for their amelioration
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