Using learning technology in university courses: do styles matter?

Purpose – The purpose of this paper is to explore the relevance of three different types of styles measure for students' learning in a large introductory university course in psychology, using information technology to enhance teaching. The paper examines the relationship between styles, the usage of learning technology, and academic performance in this course. Design/methodology/approach – Styles are measured using approaches to learning, thinking styles, and cognitive styles. The usage of the online material is measured by considering both time spent on the resources and the amount of material viewed (pages and hits) as well as tools used. Findings – The findings are that the academic performance of students who used the online resources is significantly higher than those who either choose to not use the online materials at all or choose to use to the materials to a lesser extent. It is determined that the measure of approaches to learning (approaches and study skills inventory for students) is the stronger predictor for successful use of the material. Research limitations/implications – Using a reasonably sized sample in an ecologically valid context offered the opportunity to put styles into context and to consider the practical use of styles. This research is limited by the context and the particular sample. It is also difficult to completely exclude the fact that students using the extra material are generally more motivated and would have obtained better grades even without the resources. Originality/value – This paper offers further evidence for the relations between different measures of styles and evaluates the effects that styles might have on usage of online material and academic performance

MOLECULAR CHARACTERIZATION, STRESS RESPONSES AND SPECIFIC ENZYMATIC ACTIVITIES OF DEKKERA/BRETTANOMYCES BRUXELLENSIS WINE STRAINS: STRATEGIES OF ANALYSIS AND CONTROL IN THE OENOLOGICAL FIELD.

Among yeasts responsible for wine spoilage, Dekkera/Brettanomyces bruxellensis is the species on which the scientific community has the highest interest. This fact is documented by an increasing in the international publications and by the beginning of the genome sequencing. Recently, it has been traced the evolutional D. bruxellensis lineage by the analysis of promoter sequences, which separated from the Saccharomyces yeasts more than 200 mya. Spoilage caused by D./B. bruxellensis is mainly due to the following issues: \uf0fc this species remains viable and active in beverages preserved by extreme abiotic stress (anaerobiosis, up to 12-13% ethanol (v/v), minimal amounts of fermentable sugars); \uf0fc the adopted treatments (sulphiting, membrane filtration, transfer of wine to sanitized barrels) are not always effective. \uf0fc the off-flavours produced by Brettanomyces include volatile phenols characterised by disagreeable odours. The aim of this thesis was to develop strategies in order to analyse and control the wine spoilage linked to D./B. bruxellensis species. As concern the first issue, spoilage microbial analysis, the present PhD thesis describes: i) the development of new methods for D./B. bruxellensis molecular typing; ii) the phenotypic biodiversity of D./B. bruxellensis species. The topics on the microbial spoilage control were: iii) D./B. bruxellensis response to stress conditions. i) Studies on the natural distribution of D./B. bruxellensis have shown an existing high intraspecies polymorphism degree which is probably due to a fusion event among genomes or to the lacking of a sexual state. Moreover, since D./B. bruxellensis has been mainly associated to fermented beverages that represent mutagenic environments determining the frequent genome rearrangement of D./B. bruxellensis. Genetic variations are usually accumulated with a higher frequency in DNA regions that are not linked to any gene function respect to the coding regions such as introns. Thus, they are considered good indicators in evolutional studies; in S. cerevisiae, the lariat branch point TACTAAC and the 5\u2019 splice site GTATGT (5\u2019ss) are conserved sequences that were used to build primers for the Intron Splice Site amplification analysis (ISS-PCR) described for inter- and intraspecific characterisation of S. cerevisiae. The main goals of this first topic was to develop new methods for D./B. bruxellensis molecular typing. The setting up of a multiplex PCR protocol throughout the use of modified oligonucleotides that targeted 5\u2019ss -GTAAGT- has confirmed a high polymorphism among D. bruxellensis genomes. Thus, a further optimisation of the primers, a simple capillary electrophoresis protocol that can accurately separates the amplified fragments and clear rules for the ISS profiles elaboration were applied. The results points out that the genetic signatures obtained exploiting the ISS as molecular targets are able to show genetic differences that, up to now, only other laborious technique can put in evidence (Karyotyping, PFGE-RFLP, AFLP). The proposed protocol has proved to be reliable and robust. Moreover, considering that a positive correlation between the extent of non-protein-coding DNA and the eukaryotic complexity degree has been observed, the ISS fingerprinting can represents a useful tool to analyse the evolution rate of a yeast species. ii) D./B. bruxellensis yeasts have evolved numerous developmental options in order to adapt and survive the changing status of the environment. Independent studies showed that distinct genetic groups of D./B. bruxellensis can have different physiological characteristics and strong differences in their ability to produce 4-ethylphenols. The main goal of second topic was to characterise D./B. bruxellensis from a phenotipic point of view. In particular, the physiological diversity within D./B. bruxellensis strains was investigated studying the growth and the production of volatile phenols and biogenic amines under a wine model condition. Moreover, the carbon compounds assimilation, H2S production, and vinylphenol reductase (VPR) activity were also analysed. The potential hazard of spoilage when D./B. bruxellensis grows in oenological conditions was confirmed since most of the analysed strains were able to produce volatile phenols or showed a detectable VPR specific activity. Actually metabolic traits, as growth rate and off-flavour production, proved to be related and strain-dependent suggesting that an early detection and identification of \u201cfast-growing yeasts\u201d and \u201cfast volatile phenols producers\u201d could be essential to introduce adequate corrective measures. The experiments on carbon assimilation revealed that about 30% of the analysed yeasts has a own pattern in the utilization of carbonious sources. Three different ranges of VPR activity and H2S production were used to assign the physiological profiles. Combining the results from the three phenotypic experiments, about 70% of the CBS collection can be discriminated at strain level. The present work suggested that the chromosomal rearrangement occurred in this species has generated strains with a high physiological polymorphic state. iii) A goal of the wine industry is to reduce the risk of wine being spoiled by microbial activity. The main aim of the third topic of this research was to study the response to stress conditions in D./B. bruxellensis due to the yeast exposition to an electric current treatment and exogenous SO2. Results indicated that a similar effect occurred on cells after the current treatment in comparison to the SO2 exposition; both treatments resulted in a reduced microbial cell survival in the studied red wine. The kinetics of volatile phenol accumulation confirmed that, the use of an electric field could be adequate to hinder the yeast spoilage. As concern the latter issue, the SO2 resistance, a metabolomic study on the effect of the SO2 addiction to D./B. bruxellensis cultures was carried out too. Results displayed that among the metabolic pathways resulted to be affected by exogenous sulphite concentration, aminoacid metabolisms seem to be involved in the SO2 tolerance. Unlike what was observed in S. cerevisiae, neither adenine nor methionine modified the toxicity level of SO2 under laboratory conditions. The ethanol concentration seems to increase the sensitivity to sulphite suggesting that a membrane system, such as the sulphite efflux pump of S. cerevisiae, could be present in this species. In conclusion, the main research products of this PhD thesis were: \uf0fc a new PCR protocol to typing D./B. bruxellensis that uses specific primers for this yeast species, and a precise and reliable fragment separation protocol by capillary electrophoresis. Actually, this method shows a high reproducibility (94%), it is rapid in comparison to other techniques that in the past allowed a discrimination at strain level of D./B. bruxellensis isolates (Karyotyping, RFLP-PFGE, AFLP, etc.), and it represents a useful tool to monitor the yeast evolution rate; \uf0fc the collection of D./B. bruxellensis phenotypic features that never have been used to evaluate the biodiversity degree in this species, such as the VPR specific activity, H2S production, and the assimilation of carbon compounds different from ones found in wine. The compilation of a database collecting both genetic and phenotypic traits of different D./B. bruxellensis strains is the future perspective to offer an efficient way to counteract this spoilage yeast; \uf0fc a new technology to reduce the survival of D. bruxellensis in wine using a low electric current (LEC) treatment. \uf0fc the understanding of some metabolic mechanisms involved in the SO2 response in D./B. bruxellensis. This step will allow the following upgrade toward the study of molecular mechanisms, and metabolic pathways that this yeast can activate to protect itself against the exposure to high concentration of exogenous sulphur dioxide

Occurrence and Analysis of Sulfur Compounds in Wine

Sulfur compounds play an important role in the sensory characteristics of wine. These molecules can derive from the grape, in which the non-volatile forms are usually present as glycosylated molecules, the metabolic activities of yeast and bacteria, the chemical reactions taking place during the wine aging and storage, and the environment. The sulfur compounds include molecules positively correlated to the aromatic profile of wine, namely the volatile thiols, and are responsible for certain defects, imparting notes described as cabbage, onion, rotten egg, garlic, sulfur and rubber. Due to the low concentration of these molecules in wine, their high reactivity and the matrix complexity, the analytical methods which enable their detection and quantification represent a challenge. The solid phase microextraction (SPME) technique has been developed for sulfur compounds associated with off-flavors. The analysis of volatile thiols usually requires a derivatization followed by gas chromatography (GC)-MS or UPLC-MS methods. Besides the sulfur-containing aromas, another sulfur compound that deserves mention is the reduced glutathione (GSH) which has been widely studied due to its antioxidant properties. The analysis of GSH has been proposed using a liquid chromatography technique (HPLC or UPLC) coupled with fluorescence, MS and UV detectors

From learning to e-learning: mining educational data. A novel, data-driven approach to evaluate individual differences in students’ interaction with learning technology

In recent years, learning technology has become a very important addition to the toolkit of instructors at any level of education and training. Not only offered as a substitute in distance education, but often complementing traditional delivery methods, e-learning is considered an important component of modern pedagogy. Particularly in the last decade, learning technology has seen a very rapid growth following the large-scale development and deployment of e-learning financed by both Governments and commercial enterprises. These turned e-learning into one of the most profitable sectors of the new century, especially in recession times when education and retraining have become even more important and a need to maximise resources is forced by the need for savings. Interestingly, however, evaluation of e-learning has been primarily based on the consideration of users’ satisfaction and usability metrics (i.e. system engineering perspective) or on the outcomes of learning (i.e. gains in grades/task performance). Both of these are too narrow to provide a reliable effect of the real impact of learning technology on the learning processes and lead to inconsistent findings. The key purpose of this thesis is to propose a novel, data-driven framework and methodology to understand the effect of e-learning by evaluating the utility and effectiveness of e-learning systems in the context of higher education, and specifically, in the teaching of psychology courses. The concept of learning is limited to its relevance for students’ learning in courses taught using a mixture of traditional methods and online tools tailored to enhance teaching. The scope of elearning is intended in a blended method of delivery of teaching. A large sample of over 2000 students taking psychology courses in year 1 and year 2 was considered over a span of 5 five years, also providing the scope for the analysis of some longitudinal sub-samples. The analysis is accomplished using a psychologically grounded approach to evaluation, partially informed by a cognitive/ behavioural perspective (online usage) and a differential perspective (measures of cognitive and learning styles). Relations between behaviours, styles and academic performance are also considered, giving an insight and a direct comparison with existing literature. The methodology adopted draws heavily from data mining techniques to provide a rich characterisation of students/users in this particular context from the combination of three types of metrics: cognitive and learning styles, online usage and academic performance. Four different instruments are used to characterise styles: ASSIST (Approaches to learning, Entwistle), CSI (Cognitive Styles Inventory, Allinson & Hayes), TSI (Thinking Styles Inventory and the mental self-government theory, Sternberg) and VICS-WA (Verbal/Imager and Wholistc/Analytic Cognitive style, Riding, Peterson) which were intentionally selected to provide a varied set of tools. Online usage, spanning over the entire academic year for each student, is analysed applying web usage mining (WUM) techniques and is observed through different layers of interpretation accounting for behaviours from the single clicks to a student’s intentions in a single session. Academic performance was collated from the students’ records giving an insight in the end-of-year grades, but also into specific coursework submissions during the whole academic year allowing for a temporal matching of online use and assessment. The varied metrics used and data mining techniques applied provide a novel evaluation framework based on a rich profile of the learner, which in turn offers a valuable alternative to regression methods as a mean to interpret relations between metrics. Patterns emerging from styles and the way online material is used over time, proved to be valuable in discriminating differences in academic performance and useful in this context to identify significant group differences in both usage and academic performance. As a result, the understanding of the relations between e-learning usage, styles and academic performance has important practical implications to enhance students’ learning experience, in the automation of learning systems and to inform policymakers of the effects of learning technology has from a user and learner-centred approach to learning and studying. The success of the application of data mining methods offers an excellent starting point to explore further a data-driven approach to evaluation, support informed design processes of e-learning and to deliver suitable interventions to ensure better learning outcomes and provide an efficient system for institutions and organization to maximise the impact of learning technology for teaching and training

Tryptophan-ethylester, the false (unveiled) melatonin isomer in red wine

Among the food plants, the presence of melatonin in grapes (Vitis vinifera L.) deserves particular attention because of the production of wine, an alcoholic beverage of economic relevance and with putative healthy effects. Furthermore, melatonin isomers have been detected in wine too. Recently, one of these isomers has been identified as tryptophan-ethylester, a compound with the same molecular weight of melatonin. In this Commentary, we briefly comment the source(s) of tryptophan-ethylester in wine and the putative nutritional role(s)

Why do grape-based fruit wines could be “super” magic?

In Europe, the global consumption of wine is decreasing and new alternatives of wine have been appearing on the market. The attractiveness of these products rely on the fact that they are inexpensive and easy to drink, with low alcohol content and obtained by mixing wines with fruit juices or flavoring wine. While fruit wines represent an ancient art [1], no studies have investigated the production of beverages that are obtained by the co-fermentation of grape and fruit. The formulation of new mixed-fruit wines could represent the basis for reducing post-harvest fruit losses and contribute to the economy of the existing wine industry. Moreover, throughout the selection of useful yeasts that drive the alcoholic fermentation, the final products could be enriched in novel active bio-functional compounds not found in traditional wines. The research activity has involved the setup of fermentation trials using grape must and fruit juices of strawberry, peach, cherry and kiwi. Must fermentations were carried out inoculating Saccharomyces cerevisiae and Torulaspora delbruekii species in four musts obtained by blending grape must (Chardonnay and Cabernet Sauvignon) and juices at 80:20 and 60:40 grape:fruit juice proportion. The aromatic profile was determined by GC-MS. S. cerevisiae was able to exhaust the available sugars in all trials. In particular, based on the proportion used, alcohol was 3-5% less in wines prepared with red grape and 6-7% (v/v) less in case of white grape. T. delbruekii showed a good fermentation performance as well, suggesting its potential use as starter yeast. Only negligible difference was found for the pH, while the total acidity was higher for mixed-fruit wines obtained with must from white grape and at the 60:40 proportion. In particular, the high level of citric acid detected (up to 8 g/L) in some products could exert a beneficial effect by protecting the wine components, bio-functional compounds included, against oxidation

Corrigendum: Investigating the Effect of Selected Non-Saccharomyces Species on Wine Ecosystem Function and Major Volatiles [Front. Bioeng. Biotechnol., 6, (2018) (169)] DOI: 10.3389/fbioe.2018.00169

In the original article, there was a mistake in Figure 2 as published. The order of the graphs (A-H) is incorrect and does not match the caption nor the in-text citation. The corrected Figure 2 appears below. The authors apologize for this error and state that this does not change the scientific conclusions of the article in any way. The original article has been updated

Melatonin and its derivatives in red wine: contribution of fermenting microorganisms

Melatonin (MEL) is an indoleamine produced mainly by the pineal gland in vertebrates and it has a significant role in regulation of circadian rhythm, mitigation of sleeping disorder and jet lag. It has been found in medicinal plants, plant foods including seeds, fruits and fermented beverages, and, therefore, its occurrence in plants is now ascertained. In grapes and wines, MEL ranges from sub-ng/g to \ub5g/g and from sub-ng/mL to ng/mL, respectively, with varying levels according to both endogenous and exogenous factors. In addition, MEL isomers and tryptophan-ethylester (TEE, a compound with the same molecular weight of MEL) have recently been detected in wine and the fermenting yeast plays an important role for their production [1]. It has been suggested that, in synergy with polyphenols, MEL in wine may contribute to maximize the health-promoting effects of Mediterranean diet. The research aimed to validate an analytical method for the simultaneous detection of MEL, TEE and tryptophan. The sample preparation was developed by means of SPE purification. Purified samples of synthetic wine solution (tartaric acid 5 g/L, ethanol 12% [v/v], pH 3.2) and red wine spiked with the analytes of interest were analyzed by liquid chromatography coupled with both fluorescence and mass spectrometry detectors. MEL, TEE and tryptophan were successfully detected and quantified by both the analytical conditions adopted. The response was linear for all the investigated compounds and it was comparable between synthetic wine solution and red wine. The recovery was higher than 85% and the relative standard deviation was lower than 10%. The developed method was applied for the analysis of red wine samples produced in a cold area of North of Italy. Preliminary results showed an increase of TEE concentrations suggesting the possible positive influence of secondary fermentations other than the alcoholic fermentation

Wine industry’s attitude towards oenological yeasts : Italy as a case study

Yeast inoculation is a widespread practice in winemaking in order to control the must fermentation. However, the use of indigenous wine yeasts can enrich wine quality and differentiate wine styles. Yeast cream preparation (CRY), recently accepted by the International Organization of Vine and Wine, could allow an easier usage of autochthonous yeasts. This work aimed at investigating the actual Italian wine industry\u2019s attitude towards the available formulations of commercial wine yeasts with attention to CRY. Moreover, this study evaluated the perception of wineries toward indigenous yeasts in both winemaking and marketing viewpoints. Data show different levels of knowledge and use about the available yeast formulations. In general, there is not a predominantly positive or negative participants\u2019 opinion regarding the use of indigenous yeasts. Wineries using CRY (4% of the sample) mainly adopt them as a part of the production in order to compare the wines with the ones traditionally obtained with commercial yeasts. CRY is perceived by some interviewees as a potential tool to increase communication and product differentiation. This survey could have anticipated future trends in the use of yeast formulations, determined by the market demands for diversified, unique, and environmentally sustainable products, that can allow an accessible application of precision enology

LC-MS/MS-Based Profiling of Tryptophan-Related Metabolites in Healthy Plant Foods

Food plants contain hundreds of bioactive phytochemicals arising from different secondary metabolic pathways. Among these, the metabolic route of the amino acid Tryptophan yields a large number of plant natural products with chemically and pharmacologically diverse properties. We propose the identifier "indolome" to collect all metabolites in the Tryptophan pathway. In addition, Tryptophan-rich plant sources can be used as substrates for the fermentation by yeast strains to produce pharmacologically active metabolites, such as Melatonin. To pursue this technological development, we have developed a UHPLC-MS/MS method to monitor 14 Tryptophan, Tryptamine, amino-benzoic, and pyridine metabolites. In addition, different extraction procedures to improve the recovery of Tryptophan and its derivatives from the vegetal matrix were tested. We investigated soybeans, pumpkin seeds, sesame seeds, and spirulina because of their botanical diversity and documented healthy effects. Four different extractions with different solvents and temperatures were tested, and water extraction at room temperature was chosen as the most suitable procedure to extract the whole Tryptophan metabolites pattern (called by us "indolome") in terms of ease, high efficiency, short time, low cost, and sustainability. In all plant matrices, Tryptophan was the most abundant indole compound, while the pattern of its metabolites was different in the diverse plants extracts. Overall, 5-OH Tryptamine and Kynurenine were the most abundant compounds, despite being 100-1000-fold lower than Tryptophan. Melatonin was undetected in all extracts, but sesame showed the presence of a Melatonin isomer. The results of this study highlight the variability in the occurrence of indole compounds among diverse food plants. The knowledge of Tryptophan metabolism in plants represents a relevant issue for human health and nutrition