Per presentare una disciplina curiosa e uno studio stimolante, per potenziare passione e vivacita intellettuale

ItL'uso della matematica nella società è cambiato profondamente negli ultimi decenni. Ciò ha influito sul suo ruolo nel percorso educativo che ha anche perso, così, una visione organica. E' necessario che la scuola della progettualità e dell'autonomia recuperi l'unitarietà del sapere, e riconquisti una visione globale del processo educativo. Sin dalla scuola di base può essere stimolata la creatività di ogni studente, con una scuola che guidi l'alunno a ricercare la conoscenza non solo con la logica e il ragionamento, ma anche con l'intuito e la fantasia e con una scuola che stimoli la curiosità, che sia attenta ai bisogni degli studenti e che ne favorisca il protagonismo in un clima di collaborazione. Ovviamente non è facile abbandonare la comoda via dei programmi tradizionali,i consueti criteri di verifica e di valutazione. La via della sperimentazione è più complessa e rischiosa. Nel lavoro si presentano aspetti e spunti particolari di argomenti che rendono la matematica curiosa ed affascinante quali i bioritmi ed i frattali e stimolante quale la crittografia. Si discutono, quindi, celebrazioni di organizzazioni mondiali quale, l'UNESCO, e conquiste sociali e civili di grandi scienziati che suscitano forti passioni ed evidenziano profondo spirito critico. Infine si presentano argomenti ludici e divertenti che richiedono creatività e fantasia mostrando matematica che stimola vivacità di pensiero e potenzia le capacità intellettuali

Coupling of Josephson flux-flow oscillators to an external RC load

We investigate by numerical simulations the behavior of the power dissipated in a resistive load capacitively coupled to a Josephson flux flow oscillator and compare the results to those obtained for a d.c. coupled purely resistive load. Assuming realistic values for the parameters R and C, both in the high- and in the low-Tc case the power is large enough to allow the operation of such a device in applications.Comment: uuencoded, gzipped tar archive containing 11 pages of REVTeX text + 4 PostScript figures. To appear in Supercond. Sci. Techno

Digital Platform Ecosystem Governance: Preliminary Findings and Research Agenda

This paper explores collaborative governance in digital platform ecosystems and the governance challenges that may occur in such environments. We analyze three different digital platform ecosystems and identify six unresolved key governance issues that we believe are central to the type of digital platform ecosystems we address. This paper has three contributions. First, we add to the literature on digital platform ecosystems by revealing a set of governance challenges regarding ecosystem forming and sustainability. Second, our findings may serve as recommendations for organizations that are planning to establish or that are already running an ecosystem based on a digital platform. Third, we contribute to digital platform ecosystem research by proposing an agenda for future research in this area

Cytosolic delivery of nucleic acids: The case of ionizable lipid nanoparticles

Ionizable lipid nanoparticles (LNPs) are the most clinically advanced nano-delivery system for therapeutic nucleic acids. The great effort put in the development of ionizable lipids with increased in vivo potency brought LNPs from the laboratory benches to the FDA approval of patisiran in 2018 and the ongoing clinical trials for mRNA-based vaccines against SARS-CoV-2. Despite these success stories, several challenges remain in RNA delivery, including what is known as “endosomal escape.” Reaching the cytosol is mandatory for unleashing the therapeutic activity of RNA molecules, as their accumulation in other intracellular compartments would simply result in efficacy loss. In LNPs, the ability of ionizable lipids to form destabilizing non-bilayer structures at acidic pH is recognized as the key for endosomal escape and RNA cytosolic delivery. This is motivating a surge in studies aiming at designing novel ionizable lipids with improved biodegradation and safety profiles. In this work, we describe the journey of RNA-loaded LNPs across multiple intracellular barriers, from the extracellular space to the cytosol. In silico molecular dynamics modeling, in vitro high-resolution microscopy analyses, and in vivo imaging data are systematically reviewed to distill out the regulating mechanisms underlying the endosomal escape of RNA. Finally, a comparison with strategies employed by enveloped viruses to deliver their genetic material into cells is also presented. The combination of a multidisciplinary analytical toolkit for endosomal escape quantification and a nature-inspired design could foster the development of future LNPs with improved cytosolic delivery of nucleic acids

Are we truly wicked when gossiping at work? The role of valence, interpersonal closeness and social awareness

This paper questions the belief that gossip is always damaging and that people are more interested in negative than in positive information about others. Starting from this, we seek to understand whether a certain valenced gossip (positive vs. negative and malicious vs. non-malicious) is more likely to be spread in the workplace. We test this relationship through three experimental studies by considering the moderating effect of the social linkages among the actors involved in the gossip. We found that positive and non-malicious gossip are more likely to be shared with co-workers especially when the gossip object belongs to the receiver's social group and when the gossiper reckons that the receiver may verify the news heard. We interpret these results with the lens of impression management, in that people transmit certain gossip to their co-workers with the aim of gaining social status and reputation within their organization, fostering their social bonds

Impact of lignans in oilseed mix on gut microbiome composition and enterolignan production in younger healthy and premenopausal women: An in vitro pilot study

Background: Dietary lignans belong to the group of phytoestrogens together with coumestans, stilbenes and isoflavones, and themselves do not exhibit oestrogen-like properties. Nonetheless, the gut microbiota converts them into enterolignans, which show chemical similarity to the human oestrogen molecule. One of the richest dietary sources of lignans are oilseeds, including flaxseed. The aim of this pilot study was to determine the concentration of the main dietary lignans in an oilseed mix, and explore the gut microbiota-dependent production of enterolignans for oestrogen substitution in young and premenopausal women. The oilseed mix was fermented in a pH-controlled batch culture system inoculated with women's faecal samples. The lignan content and enterolignan production were measured by ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS), and the faecal-derived microbial communities were profiled by 16S rRNA gene-based next-generation sequencing. Results: In vitro batch culture fermentation of faecal samples inoculated with oilseed mix for 24 h resulted in a substantial increase in enterolactone production in younger women and an increase in enterodiol in the premenopausal group. As for the gut microbiota, different baseline profiles were observed as well as different temporal dynamics, mainly related to Clostridiaceae, and Klebsiella and Collinsella spp. Conclusions: Despite the small sample size, our pilot study revealed that lignan-rich oilseeds could strongly influence the faecal microbiota of both younger and premenopausal females, leading to a different enterolignan profile being produced. Further studies in larger cohorts are needed to evaluate the long-term effects of lignan-rich diets on the gut microbiota and find out how enterolactone-producing bacterial species could be increased. Diets rich in lignans could potentially serve as a safe supplement of oestrogen analogues to meet the cellular needs of endogenous oestrogen and deliver numerous health benefits, provided that the premenopausal woman microbiota is capable of converting dietary precursors into enterolignans.[Figure not available: See fulltext.

Leukocyte numbers and function in subjects eating n-3 enriched foods: selective depression of natural killer cell levels

Introduction While consumption of omega-3 long-chain polyunsaturated fatty acids (n-3 LCPUFA) has been recommended for those at risk of inflammatory disease such as rheumatoid arthritis, the mechanism of their anti-inflammatory effect remains to be clearly defined, particularly in relation to the dose and type of n-3 LCPUFA. The objective of this study was to determine whether varying the levels of n-3 LCPUFA in erythrocyte membrane lipids, following dietary supplementation, is associated with altered numbers and function of circulating leukocytes conducive to protection against inflammation. Methods In a double-blind and placebo-controlled study, 44 healthy subjects aged 23 to 63 years consumed either standard or n-3 LCPUFA-enriched versions of typical processed foods, the latter allowing a target daily consumption of 1 gram n-3 LCPUFA. After six months, peripheral blood leukocyte and subpopulation proportions and numbers were assessed by flow cytometry. Leukocytes were also examined for lymphoproliferation and cytokine production, neutrophil chemotaxis, chemokinesis, bactericidal, adherence and iodination activity. Erythrocytes were analyzed for fatty-acid content. Results Erythrocyte n-3 LCPUFA levels were higher and absolute leukocyte and lymphocyte numbers were lower in subjects consuming n-3 enriched foods than in controls. There were no changes in the number of neutrophils, monocytes, T cells (CD3+), T-cell subsets (CD4+, CD8+) and B cells (CD19+). However, natural killer (NK) (CD3-CD16+CD56+) cell numbers were lower in n-3 supplemented subjects than in controls and were inversely related to the amount of eicosapentaenoic acid or docosahexaenoic acid in erythrocytes. No significant correlations were found with respect to lymphocyte lymphoproliferation and production of IFN-γ and IL-2, but lymphotoxin production was higher with greater n-3 LCPUFA membrane content. Similarly, neutrophil chemotaxis, chemokinesis, bactericidal activity and adherence did not vary with changes in erythrocyte n-3 LCPUFA levels, but the iodination reaction was reduced with higher n-3 LCPUFA content. Conclusion The data show that regular long-term consumption of n-3 enriched foods leads to lower numbers of NK cells and neutrophil iodination activity but higher lymphotoxin production by lymphocytes. These changes are consistent with decreased inflammatory reaction and tissue damage seen in patients with inflammatory disorders receiving n-3 LCPUFA supplementation.Violet R Mukaro, Maurizio Costabile, Karen J Murphy, Charles S Hii, Peter R Howe and Antonio Ferrant

Automated user modeling for personalized digital libraries

Digital libraries (DL) have become one of the most typical ways of accessing any kind of digitalized information. Due to this key role, users welcome any improvements on the services they receive from digital libraries. One trend used to improve digital services is through personalization. Up to now, the most common approach for personalization in digital libraries has been user-driven. Nevertheless, the design of efficient personalized services has to be done, at least in part, in an automatic way. In this context, machine learning techniques automate the process of constructing user models. This paper proposes a new approach to construct digital libraries that satisfy user’s necessity for information: Adaptive Digital Libraries, libraries that automatically learn user preferences and goals and personalize their interaction using this information