L’acquisizione dell’inglese da parte di apprendenti italiani in contesti non guidati: l’errore linguistico in età prescolare

Nel corso degli ultimi decenni, la ricerca su ELT si è concentrata sul ruolo delle nuove tecnologie nell’apprendimento, considerando tutte le forme di social media, cartoni animati e video giochi, in quanto tali materiali possono mantenere alti i livelli di interesse, sostenendo così la motivazione. In particolare, i cartoni presentano una combinazione di linguaggio verbale e non verbale, offrendo la possibilità di sviluppare diversi livelli di analisi, favorendo sia un approccio linguistico sia uno culturale. Gli effetti positivi dei cartoni sull’apprendimento sono stati comprovati da diverse ricerche, ma questo contesto di riferimenti deve essere ridefinito se si prende in considerazione l’apprendimento in età prescolare. Al fine di analizzare un apprendimento che è sia formale sia informale, la presente ricerca considererà gli effetti che diverse tipologie di cartoni hanno sull’apprendimento della lingua inglese per la valutazione delle abilità di speaking, la conoscenza del lessico e la motivazione, prestando particolare attenzione al ruolo dell’errore linguistico. Over the past decades, ELT research has focused on the role of ICT in learning, considering all the forms of social media, cartoons, and videogames, since they can maintain high levels of interest, thus sustaining motivation. In particular, cartoons present a combination of verbal and nonverbal language, offering the opportunity to develop different levels of analysis, favouring a linguistic focus and a cultural one. The positive effects of cartoons on learning are proved by several researches, but this background of references must be re-structured if preschool children’s learning is considered. In order to analyse a learning that is both formal and informal, the present research will muse on the effects that different typology of cartoons have on English learning process in order to assess speaking skills, vocabulary knowledge, and motivation, paying specific attention to the role played by errors/mistakes

Recent Advances in the Study of Marine Microbial Biofilm: From the Involvement of Quorum Sensing in Its Production up to Biotechnological Application of the Polysaccharide Fractions

The present review will explore the most relevant findings on marine microbial biofilm, with particular attention towards its polysaccharide fraction, namely exopolysaccharide (EPS). EPSs of microbial origin are ubiquitous in nature, possess unique properties and can be isolated from the bacteria living in a variety of habitats, including fresh water or marine environments, extreme environments or different soil ecosystems. These biopolymers have many application in the field of biotechnology. Several studies showed that the biofilm formation is closely related to quorum sensing (QS) systems, which is a mechanism relying on the production of small molecules defined as "autoinducers" that bacteria release in the surrounding environment where they accumulate. In this review, the involvement of microbial chemical communication, by QS mechanism, in the formation of marine biofilm will also be discussed

Polysaccharides from Wastes of Vegetable Industrial Processing: New Opportunities for Their Eco-Friendly Re-Use

Natural polysaccharides constitute a major group of biopolymers widespread in the whole vegetable kingdom. Plant polysaccharides comprise highly heterogeneous biopolymers that play diverse biological roles as structural elements, energy reserve and biological signalling. Polysaccharides from natural sources have attracted significant interest as biotechnological products, due to their commercial uses in a wide range of industrial applications. Some of them, for example, possess strong antigenic and antipathogenic activities and are successfully employed by the pharmaceutical industry for the formulation of vaccines or as a matrix for drug-delivery applications; others are utilised as food additives taking advantage of their physical-chemical properties (emulsifying power, viscoelasticity, polyelectrolyte, adherence, bio-compatibility, stabilizer, etc). Production of these biopolymers for industrial applications has both economic and environmental costs, depending on the starting materials used as feedstocks and on the chemical/thermal treatments required for their extraction. Recently, wastes from industrial processing of vegetables for food production have been proposed as potential sources of useful polysaccharides. Indeed, transformation and packaging of fruits and vegetables generates huge amounts of wastes, since only a fraction of the incoming biomass is effectively used. The management of such waste biomasses is a problem worldwide, from both economic and environmental standpoints, and therefore research is encouraged to implement new strategies for their re-use. An advantageous option is the extraction of value added chemicals, including different kinds of polysaccharides, besides chemically different species such as polyunsaturated fatty acids, natural pigments, tannins, carotenoids, antioxidants etc. Treatment of vegetable residues by means of newly and environmentally sustainable extraction techniques represents at the moment a fascinating challenge for the valorisation of agro-industrial wastes. Remarkable examples in this framework are represented by polysaccharides isolated from wastes of tomato industrial processing and of tropical fruit juices production based on granadilla, a fruit species of Passiflora, distributed mainly in the warm temperate and tropical regions of America and Africa. These polysaccharides resulted to possess useful biotechnological properties and interesting biological activities. An accurate chemical characterization demonstrated that the main biopolymer obtained from tomato wastes was an heteropolymer with a molecular weight higher than 1 ×106 Da constituted by glucose/ xylose/ galactose/ galactosamine/ glucosamine/ fucose in a relative molar ratio of 1: 0.9: 0.5: 0.4: 0.2: trace, whereas the polysaccharide isolated from waste peels of granadilla (Passiflora liguralis) fruits (with a molecular weight higher than 1 ×106 Da as well) was characterised by the presence of six different sugar residues: xylose/ glucose/ galactose/ galactosamine/ unknown component/ fucose in the relative ratios of 1:0.5:0.2:0.06:0.05:trace. The study of rheological properties showed for both biopolymers an high thermal resistance and an high viscosity, depending, in particular for granadilla waste polysaccharide, on concentration and pH, with a maximum value of 1.4  at a concentration of 3% in distilled water and a maximum value of 7.0  in citrate buffer solution. The main point of interest was represented by their suitability to produce elastic and biodegradable films potentially useful in agriculture for mulching applications in fields protection. Further studies were performed to evaluate the biological activity of these biopolymers. Tomato waste polysaccharides resulted to inhibit NF-κB activation and iNOS gene expression in J774 macrophages by preventing the reactive species production, thus suggesting a key role of these compounds in controlling oxidative stress and/or inflammation. Biological activity of polysaccharides from granadilla peels was assessed by means of brine shrimp bioassay: the isolated compound was able to strongly inhibit the cytotoxic effects produced by avarol, whose LD50 was increased of about 10-fold with respect to the control in the absence of polysaccharide. More recent studies have been focused on lemon wastes. Citrus processing produces a considerable amount of waste biomass called “lemon pomace” consisting of peels (flavedo and albedo), pulp and seeds, mainly composed by water, soluble sugars and fibres, together with other compounds such as oils, flavonoids and vitamins. Lemon wastes, generated in huge amounts by Italian industries for “Limoncello” liquor production, have been treated in order to separate useful polysaccharides. A major polysaccharide fraction was isolated and purified: analysis by means of gel filtration allowed to determine a molecular weight higher than 1 ×106 Da. The sugar components were identified after acid hydrolysis, by means of TLC and HPAE-PAD chromatography: the main components resulted to be galactose, galacturonic acid and arabinose. Further studies are now being implemented to study both rheological properties and biological activity of lemon polysaccharides. In conclusion, polysaccharides are among the most interesting biopolymers that can be recovered from vegetables: the use of wastes from industrial processing of different vegetables together with eco-friendly extraction techniques allowed the isolation of remarkable polysaccharides. Some of them showed to possess interesting rheological properties, potential biotechnological applications and finally promising bioactivities as potential anti-inflammatory agents, as tested in different biological model systems

Microwave and ultrasound pre-treatments for ‘Rocha’ Pear: impact on drying kinetics and selected quality attributes

Rocha’pear (Pyruscommunis L.) is the main cultivar produced in Portugal, and is classified as protected designation of origin (PDO).This pear fruit is characterized by its own typical and specific properties, such as pleasant flavor, crispness and also sweetness.Pears are rich in polyphenols with strong antioxidant activity,offering health promoting benefits. In order to extend its shelf life and increase availability along the year, drying processes are widely applied as a good alternative method for fruits preservation. Drying is used to improve food stability, decrease moisture content and microbial activity, and minimize physico-chemical changes during storage. However, drying process conditions (i.e. air temperature, time, and velocity) usually may lead to food quality degradation in terms of physico-chemical and nutritional attributes. In this context, drying combined with pre-treatments have been proposed in order to reduce the drying impact on products quality. The objective of this work was to evaluate the use of microwave and ultrasound pre-treatments on ‘Rocha’ pear drying kinetics and quality attributes (water activity, color, shrinkage, total phenolics, antioxidant activity, and texture and rehydration behavior of dried slabs).Three different samples were compared: a) Control, b) Microwave Pre-treatment (1540 MW, 4 min) (MW), and c) Ultrasound Pre-treatment (35 kHz, 10 min, 25°C) (US). Drying experiments were conducted on pear slabs (thickness and diameter of 6 and 38 mm, respectively) in a tray dryer with an air temperature of 60°C and a fixed velocity of 0.75 m/s. Pear samples pre-treated with MW had shorter drying time than control and ultrasound treated ones.Pear samples pre-treated with US showed the lowest colour changes and shrinkage, higher total phenolics and antioxidant activity, the highest rehydration capacity, and similar drying time to the control. This study contributes with information for the development of new drying pre-treatment conditions of ‘Rocha” pear fruits, as an alternative to traditional drying in an industrial context.info:eu-repo/semantics/publishedVersio

Microwave and ultrasound pre-treatments for drying of the “Rocha” Pear: impact on phytochemical parameters, color changes and drying kinetics

The objective of this research was to evaluate the effect of drying temperature and innovative pre-treatments (i.e., microwave and ultrasound) on “Rocha” pear drying behavior and quality characteristics, such as color, total phenolic content and antioxidant activity. Experiments were carried out with pear slabs subjected to microwaves (2450 MHz, 539 W, 4 min, microwave oven) and ultrasounds (35 kHz, 10 min, in an ultrasonic bath) as well as control samples. The drying process was conducted in a tray dryer at three different temperatures (50, 55 and 60 °C) and a fixed air velocity of 0.75 m/s. Microwave technology resulted in a higher quality deterioration in dried pear samples compared to those of controls and ultrasound pre-treated samples. The combined application of ultrasound pre-treatment and the higher drying temperature of 60 °C was characterized by the lowest color changes (ΔE = 3.86 ± 0.23) and higher preservation of nutritional parameters (total phenolic content, TPC = 345.60 ± 8.99; and antioxidant activity, EC50 = 8.80 ± 0.34). The drying characteristics of pear fruits were also analyzed by taking into account empirical models, with the Page model presenting the best prediction of the drying behavior. In conclusion, ultrasound application is a promising technology to obtain healthy/nutritious dried “Rocha” pear snacks as dietary sources for consumers.info:eu-repo/semantics/publishedVersio

Helicobacter pylori and Epstein-Barr virus infection in gastric diseases: Correlation with IL-10 and IL1RN polymorphism.

Introduction: Helicobacter pylori and Epstein-Barr virus (EBV) infection have recently 23 been shown to be associated with gastric diseases. Polymorphisms in genes encoding 24 cytokines such as interleukin 10 (IL-10) and interleukin 1 Receptor (IL-1RN) influence 25 cytokine secretion levels and appear to contribute to the risk of developing gastroduodenal 26 diseases. 27 To our knowledge, this is the first preliminary study to address the association of 28 coinfection with H. pylori and EBV and their correlation with genetic predisposition in the 29 development of gastric diseases. 30 Methods: Gastric biopsy samples of 96 patients with different gastric diseases were used. 31 Results: Our results showed that the rate of co-infection was higher in patients with 32 gastric cancer than in patients with normal gastric mucosa, active chronic gastritis and 33 MALT lymphoma. As regards the characterization of H. pilory strains, the 34 polymorphism s1m1i1 of vacA gene was more frequent in patients with MALT 35 Lymphoma in comparison to others, while the polymorphism s2m2i2 was most 36 frequent in patients with normal gastric mucosa. In addition, patients who tested 37 positivefor the cagA gene were more frequently those affected with gastric cancer than 38 those with inactive chronic gastritis. Similarly, the patients with oipA gene ON were more 39 frequently those with gastric cancer than those with inactive chronic gastritis. 40 Conclusion: According to our analysis, there was no correlation between coinfection 41 and polymorphisms in genes encoding IL-10 and IL-1RN. We conclude that various 42 factors can be involved in the development of gastric diseases

Microwave and ultrasound pre-treatments for ‘Rocha’ pear: impact on drying kinetics and selected quality attributes

info:eu-repo/semantics/acceptedVersio

Microgravity Promotes Differentiation and Meiotic Entry of Postnatal Mouse Male Germ Cells

A critical step of spermatogenesis is the entry of mitotic spermatogonia into meiosis. Progresses on these topics are hampered by the lack of an in vitro culture system allowing mouse spermatogonia differentiation and entry into meiosis. Previous studies have shown that mouse pachytene spermatocytes cultured in simulated microgravity (SM) undergo a spontaneous meiotic progression. Here we report that mouse mitotic spermatogonia cultured under SM with a rotary cell culture system (RCCS) enter into meiosis in the absence of any added exogenous factor or contact with somatic cells. We found that isolated Kit-positive spermatogonia under the RCCS condition enter into the prophase of the first meiotic division (leptotene stage), as monitored by chromosomal organization of the synaptonemal complex 3 protein (Scp3) and up-regulation of several pro-meiotic genes. SM was found to activate the phosphatidyl inositol 3 kinase (PI3K) pathway and to induce in Kit-positive spermatogonia the last round of DNA replication, typical of the preleptotene stage. A PI3K inhibitor abolished Scp3 induction and meiotic entry stimulated by RCCS conditions. A positive effect of SM on germ cell differentiation was also observed in undifferentiated (Kit-negative) spermatogonia, in which RCCS conditions stimulate the expression of Kit and Stra8. In conclusion, SM is an artificial environmental condition which promotes postnatal male germ cell differentiation and might provide a tool to study the molecular mechanisms underlying the switch from mitosis to meiosis in mammals

Unusual MRI findings in an immunocompetent patient with EBV encephalitis: a case report

BACKGROUND: It is well-known that Epstein-Barr virus (EBV) can affect the central nervous system (CNS). CASE PRESENTATION: Herein the authors report unusual timely Magnetic Resonance Imaging (MRI) brain scan findings in an immunocompetent patient with EBV encephalitis. Diffusion weighted MRI sequence performed during the acute phase of the disease was normal, whereas the Fast Relaxation Fast Spin Echo T2 image showed diffuse signal intensity changes in white matter. The enhancement pattern suggested an inflammatory response restricted to the brain microcirculation. Acyclovir and corticosteroid therapy was administered. After three weeks, all signal intensities returned to normal and the patient showed clinical recovery. CONCLUSION: This report demonstrates that EBV in an immunocompetent adult can present with diffuse, reversible brain white matter involvement in the acute phase of mononucleosis. Moreover, our case suggests that a negative DWI sequence is associated with a favorable improvement in severe EBV CNS infection. More extensive studies are needed to assess what other instrumental data can help to distinguish viral lesions from other causes in the acute phase of diseas

Micro structural approach of potato and pumpkin drying and rehydration

The food structure is subjected to a change of the integrity during dehydration which will affect rehydration. Changes in the underlying microstructure of this deformation and rehydration generally fails in restoring the integrity and quality of the food material to the original status. In this context, there are not many studies performed which correlate cellular structural changes to the desorption-sorption behaviour of food materials after dehydration. This study was undertaken to understand desorption-sorption behaviour of food considering potato (cv Sebago) and pumpkin (cv ecotype) as the model materials during drying and further explanations on rehydration. Pumpkin was used to construct only for dehydration and rehydration graphs. For potato SEM images were taken for dehydration and rehydration. Corresponding behaviours show the irreversible trend of dehydration-rehydration exists and changes to the scenario of relationship of the cellular structure