An extensive questionnaire about Metacognition during Emergency Remote Teaching involving more than 3000 engineering students

By 11 March 2020, the phrase “COVID-19” had officially entered everyday life across most of the word. Each level of education suddenly faced new changes and new challenges. Emergency remote teaching became widespread, and new methodologies to deliver classes and courses were adopted by educational institutions. In this paper, we focus on the impact of the remote learning experience of engineering students enrolled at the Politecnico di Milano. The subjects were recruited from all engineering courses from the first to the fifth year and were asked to complete a multidimensional survey. The survey featured 66 items regarding the participants’ perceptions of the challenges of emergency remote teaching compared with pre-COVID-19 in-person teaching. The questionnaire addressed six dimensions: the organization of emergency remote teaching, subjective well-being, metacognition, self-efficacy, identity, and socio-demographic information. In this paper, we describe the entire survey and discuss a preliminary analysis. Using Cronbach’s alpha test, a confirmatory factor analysis, and the t-test, we performed a more in-depth analysis concerning the outcomes of metacognition and self-efficacy. The data analysis suggested a small, unexpected change in the metacognition strategies. The students, in some regards, improved their learning strategies. Some other answers underlined their appreciation of the courses’ organization and the lack of relationships with their peers and teachers

An Italian large case study on Emergency Remote Teaching: factors and predictors which affect Higher Education students’ attitude

Research on concerns about Emergency Remote Teaching has focused on teaching and management strategies, with some studies considering learners’ satisfaction, reactions, learning and overall acceptance. The present large case study, based on a survey on 3,920 undergraduate and postgraduate learners, aimed at investigating Politecnico di Milano students’ self-reported experiences of the Emergency Remote Teaching after identifying the empirical factors characterising such experience and the predictors of the students’ responses. Participants’ evaluation was expressed based on a five-point Likert scale, whereby a score equal to 3 corresponded to neutrality. We validated the questionnaire empirically through factor analysis. This questionnaire consisted of 66 items across 6 sections and focused on different latent variables as well as socio-economic information about the students. Our findings highlighted both the students’ assessment of their overall online learning experience of Emergency Remote Teaching and the change in their metacognitive strategies and self-efficacy as a consequence of the new learning approach. These results did not appear to depend on the learners’ gender or their educational level of degree study, while the academic year of attendance seemed to influence their opinion on teaching. Moreover, the change in the learning approach that learners experienced in the passage from bachelor to master’s programmes was discovered to be a further predictor which might be more critical for females than males. Finally, implications for policy makers and higher education institutions for online learning in the post-pandemic scenario are discussed

Geochemistry, stable isotopes and statistic tools to estimate threshold and source of nitrate in groundwater (Sardinia, Italy)

In the European Union, nitrate vulnerable zone (NVZ) should be designed for the mitigation of nitrate (NO3−) contamination caused by agricultural practices. Before establishing new NVZ, the sources of NO3− must be recognized. A geochemical and multiple stable isotopes approach (hydrogen, oxygen, nitrogen, sulfur and boron) and statistical tools were applied to define the geochemical characteristics of groundwater (60 samples), calculate the local NO3− threshold and assess potential sources of NO3− contamination in two study areas (hereafter Northern and Southern), located in a Mediterranean environment (Sardinia, Italy). Results of the integrated approach applied to two case study, permits to highlight the strengths of integrating geochemical and statistical methods to provide nitrate source identification as a reference by decision makers to remediate and mitigate nitrate contamination in groundwater. Hydrogeochemical features in the two study areas were similar: near neutral to slightly alkaline pH, electrical conductivity in the range of 0.3 to 3.9 mS/cm, and chemical composition ranging from Ca-HCO3− at low salinity to Na-Cl− at high salinity. Concentrations of NO3− in groundwater were in the range of 1 to 165 mg/L, whereas the nitrogen reduced species were negligible, except few samples having NH4+ up to 2 mg/L. Threshold values in the studied groundwater samples were between 4.3 and 6.6 mg/L NO3−, which was in agreement with previous estimates in Sardinian groundwater. Values of δ34S and δ18OSO4 of SO42− in groundwater samples indicated different sources of SO42−. Sulfur isotopic features attributed to marine SO42− were consistent with groundwater circulation in marine-derived sediments. Other source of SO42− were recognize due to the oxidation of sulfide minerals, to fertilizers, manure, sewage fields, and SO42− derived from a mix of different sources. Values of δ15N and δ18ONO3 of NO3− in groundwater samples indicated different biogeochemical processes and NO3− sources. Nitrification and volatilization processes might have occurred at very few sites, and denitrification was likely to occur at specific sites. Mixing among various NO3− sources in different proportions might account for the observed NO3− concentrations and the nitrogen isotopic compositions. The SIAR modeling results showed a prevalent NO3− source from sewage/manure. The δ11B signatures in groundwater indicated the manure to be the predominant NO3− source, whereas NO3− from sewage was recognized at few sites. Geographic areas showing either a predominant process or a defined NO3− source where not recognize in the studied groundwater. Results indicate widespread contamination of NO3− in the cultivated plain of both areas. Point sources of contamination, due to agricultural practices and/or inadequate management of livestock and urban wastes, were likely to occur at specific sites

Bionanocomposites based on chitosan and few layers graphene. The effect of tailor-made functionalization

Bionanocomposites are an emerging class of material. They are designed and developed to achieve advanced structural and functional properties, by using biobased polymers. Among the bio-polymers, focus is on chitosan (CS), poly (N-acetyl-D-glucosamine), a copolymer of [1,4]-linked 2-acetamido-2-deoxy-D-glucopyranose and 2-amino-2-deoxy-D-glucopyranose. Research is steadily increasing on bionanocomposites with graphene and graphene related materials. It is here presented a research on bionanocomposites based on CS and graphene layers (G). Particular focus of the research was on the integration of the graphene layers in the nanocomposite. Materials were prepared based on the supramolecular interaction between CS and G. The core of the research was then on the edge functionalization of the layers. OH groups were added through the cycloaddition reaction with a biosourced pyrrole compound, serinol pyrrole (SP), carried out with the help of either thermal or mechanical energy, with an atom efficiency up to 96% and a very low E Factor. The preparation of CS/G adducts was very simple, even by using only mortar and pestle. OH groups were also added to the G edges by performing the reaction of G with KOH. The Reimer-Tiemann reaction on the G-OH adduct led to the introduction of aldehydic groups, which promote the crosslinking of CS. The CS/G adducts were characterized by means of wide angle X-ray diffraction, scanning and transmission electron microscopy, Fourier transform infrared, X-ray photoelectron and Raman spectroscopies. Thermal stability of the composites was studied by thermogravimetric analysis. Carbon papers and aerogels were prepared, studying the flexibility and the stability in various solvents in a wide pH range

The O2-scavenging Flavodiiron Protein in the Human Parasite Giardia intestinalis

The flavodiiron proteins (FDP) are widespread among strict or facultative anaerobic prokaryotes, where they are involved in the response to nitrosative and/or oxidative stress. Unexpectedly, FDPs were fairly recently identified in a restricted group of microaerobic protozoa, including Giardia intestinalis, the causative agent of the human infectious disease giardiasis. The FDP from Giardia was expressed, purified, and extensively characterized by x-ray crystallography, stopped-flow spectroscopy, respirometry, and NO amperometry. Contrary to flavorubredoxin, the FDP from Escherichia coli, the enzyme from Giardia has high O(2)-reductase activity (>40 s(-1)), but very low NO-reductase activity (approximately 0.2 s(-1)); O(2) reacts with the reduced protein quite rapidly (milliseconds) and with high affinity (K(m) < or = 2 microM), producing H(2)O. The three-dimensional structure of the oxidized protein determined at 1.9A resolution shows remarkable similarities with prokaryotic FDPs. Consistent with HPLC analysis, the enzyme is a dimer of dimers with FMN and the non-heme di-iron site topologically close at the monomer-monomer interface. Unlike the FDP from Desulfovibrio gigas, the residue His-90 is a ligand of the di-iron site, in contrast with the proposal that ligation of this histidine is crucial for a preferential specificity for NO. We propose that in G. intestinalis the primary function of FDP is to efficiently scavenge O(2), allowing this microaerobic parasite to survive in the human small intestine, thus promoting its pathogenicity

Functionalization of graphene related materials with biosourced C-3 and C-6 building blocks. From synthesis to applications

The functionalization of sp2 carbon allotropes is one of the hot research topics in advanced research on materials. Nowadays, carbon nanotubes and graphene related materials are extensively studied due to their exceptional mechanical and electrical properties. They are capable of substantially improving the properties of polymeric materials. Their functionalization is a crucial step, for allowing an even dispersion in the matrix. In this research, the functionalization of graphene related materials was performed with biosourced C-3 and C-6 molecules. They were glycerol and galactaric acid derivatives: pyrrole compounds (PyC) and 2-pyrones. The reactions for their synthesis and for the carbon allotrope functionalization were green and characterized by high atom efficiency, with a yield up to 96%. Indeed, the reactions were carried out in the absence of solvents and catalysts and adducts were obtained by simply mixing, with the help of either thermal or mechanical energy. The developed functionalization methods were successful for: carbon black, carbon nanotubes, few layers graphene. The bulk structure of the carbon substrate was left substantially unaltered: functionalization occurred in peripheral positions, at the edges of the graphene layers. Functional groups of defined chemical structure were covalently bound to the carbon material and stable adducts, up to very high temperature, were formed. Reliable hypotheses for the functionalization mechanisms were elaborated. In Figure 1b the supposed domino reaction based on the pyrrole compound, with the Diels Alder cycloaddition as the last step is represented. Such functionalization technique was developed as a pervasive technology, which allowed to pursue a variety of applications: (i) decoration with metals to obtain catalysts for the selective deuteration of pharmaceutical molecules as well as antibacterial ingredients (ii) rubber compounds for dynamic-mechanical applications (tires) (iii) conductive inks

The protective effect of the Mediterranean diet on endothelial resistance to GLP-1 in type 2 diabetes: a preliminary report

In type 2 diabetes, acute hyperglycemia worsens endothelial function and inflammation,while resistance to GLP-1 action occurs. All these phenomena seem to be related to the generation of oxidative stress. A Mediterranean diet, supplemented with olive oil, increases plasma antioxidant capacity, suggesting that its implementation can have a favorable effect on the aforementioned phenomena. In the present study, we test the hypothesis that a Mediterranean diet using olive oil can counteract the effects of acute hyperglycemia and can improve the resistance of the endothelium to GLP-1 action

Convolutional Autoencoder for Landmine Detection on GPR Scans

Buried unexploded landmines are a serious threat in many countries all over the World. As many landmines are nowadays mostly plastic made, the use of ground penetrating radar (GPR) systems for their detection is gaining the trend. However, despite several techniques have been proposed, a safe automatic solution is far from being at hand. In this paper, we propose a landmine detection method based on convolutional autoencoder applied to B-scans acquired with a GPR. The proposed system leverages an anomaly detection pipeline: the autoencoder learns a description of B-scans clear of landmines, and detects landmine traces as anomalies. In doing so, the autoencoder never uses data containing landmine traces at training time. This allows to avoid making strong assumptions on the kind of landmines to detect, thus paving the way to detection of novel landmine models