1,432 research outputs found

    Begin, After, and Later: a Maximal Decidable Interval Temporal Logic

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    Interval temporal logics (ITLs) are logics for reasoning about temporal statements expressed over intervals, i.e., periods of time. The most famous ITL studied so far is Halpern and Shoham's HS, which is the logic of the thirteen Allen's interval relations. Unfortunately, HS and most of its fragments have an undecidable satisfiability problem. This discouraged the research in this area until recently, when a number non-trivial decidable ITLs have been discovered. This paper is a contribution towards the complete classification of all different fragments of HS. We consider different combinations of the interval relations Begins, After, Later and their inverses Abar, Bbar, and Lbar. We know from previous works that the combination ABBbarAbar is decidable only when finite domains are considered (and undecidable elsewhere), and that ABBbar is decidable over the natural numbers. We extend these results by showing that decidability of ABBar can be further extended to capture the language ABBbarLbar, which lays in between ABBar and ABBbarAbar, and that turns out to be maximal w.r.t decidability over strongly discrete linear orders (e.g. finite orders, the naturals, the integers). We also prove that the proposed decision procedure is optimal with respect to the complexity class

    Operational Transformation su documenti strutturati

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    I sistemi di editing collaborativo real-time sono software che permettono agli utenti di editare lo stesso documento su siti diversi nello stesso istante. L’esperienza che deve provare ognuno degli utenti connessi al sistema deve essere tale da permettergli di modificare e di vedere le modifiche degli altri utenti in real-time. In base al contesto lavorativo, gli utenti possono collaborare in maniera sincrona o asincrona. Si necessita di arrivare a una versione convergente del documento che non dipenda dall’ordine o dai tempi in cui le operazioni sono state eseguite su di esso. Il protocollo che è stato scelto per la gestione della concorrenza delle operazioni nella trattazione di questa tesi è Operational Transformation

    La scuola neoliberale: Lo spazio della filosofia tra didattica delle competenze e soft skills

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    The article aims to investigate the transformations that educational institutions are undergoing under the pressure of European directives following neoliberal business-oriented models. Genealogical analysis and comparison with European and national institutional documentation suggest that the educational reforms of the last thirty years, focused on the logic of competencies and the business model, are designed to be a fundamental support for neoliberal subjectivation practices. The centrality of the notion of competence and the emphasis on the need to develop and apply an increasing number of knowledge measurement tools lead to the definition of an educational horizon whose main purpose is to train individuals useful to the productive system, both in terms of technical skills and values. An educational system with these objectives entails the distortion and devaluation of a whole range of knowledge areas, including philosophy. Competency-based teaching is transforming the study of philosophy from critical knowledge into a simple adaptation to evaluation systems that align with the logic of the business world: in the best-case scenario, a set of soft skills, and in the worst-case scenario, a true servant of corporate culture.L’articolo mira ad indagare le trasformazioni che stanno subendo le istituzioni formative sotto la pressione delle direttive europee secondo modelli aziendali di stampo neoliberale. L’analisi genealogica e il confronto con la documentazione istituzionale europea e nazionale suggeriscono che le riforme scolastiche degli ultimi trent’anni, centrate sulla logica delle competenze e sul modello dell’impresa, siano elaborate per essere un supporto fondamentale alle pratiche di soggettivazione neoliberale. La centralità della nozione di competenza e l’insistenza sulla necessità di sviluppare ed applicare un numero sempre maggiore di strumenti di misurazione dei saperi portano a definire un orizzonte educativo che si pone come scopo principale la formazione di individui utili al sistema produttivo, tanto sul piano delle capacità tecniche quanto sul piano valoriale. Un sistema educativo con questi obiettivi comporta lo snaturamento e la svalutazione di tutta una serie di ambiti del sapere, uno su tutto quello filosofico. La didattica delle competenze sta trasformando lo studio della filosofia da sapere critico a semplice adattamento a quei sistemi di valutazione che rispondono alle logiche del mondo dell’impresa: nella migliore delle ipotesi un insieme di soft skill, nella peggiore una vera e propria ancella della cultura aziendalista

    Dynamic Stresses of Lactic Acid Bacteria Associated to Fermentation Processes

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    Despite their negligible mass the microbial agents, starters and non starters, play a profound role in the characterization of the fermented foods in terms of chemical and sensorial properties. In fact, fermented foods may be defined as foods processed through the activity of microorganisms. Fermentation processes take a special place in the evolution of human cuisine, by altering the taste experience of food products, as well as extending the storage period. In particular, foods fermented with lactic acid bacteria (LAB) have constituted an important part of human diet and of fermentation processes (involving various foods, including milk, meat, vegetables and fruits) since ancient times. They have played an essential role in the preservation of agricultural resources and in the improvement of nutritional and organoleptic properties of human foods and animal feed. Moreover, these organisms nowadays are increasingly used as health promoting probiotics, enzyme and metabolite factories and vaccine delivery vehicles

    Primi risultati del progetto LIFE+ sulle analisi microbiologiche delle acque nel Parco dei Gessi dell’Emilia Romagna

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    Dal 2010 è in corso il Progetto Life + 08NAT/IT/000369 “Gypsum” 2, cofinanziato dall’Unione Europea, finalizzato alla tutela e gestione dei principali ambienti gessosi dell’Emilia Romagna. Nell’ambito dell’Azione A3 è previsto un monitoraggio pluriennale dei principali acquiferi carsici sotto l’aspetto chimico e microbiologico. Nel corso del primo anno sono state analizzate le acque carsiche su circa 50 punti di controllo (inghiottitoi, fiumi, torrenti in grotta, e risorgenti). In generale l’obiettivo di questa sperimentazione è quello di valutare l’impatto di sostanze di origine agricola o di altre forme di inquinamento, legate ad insediamenti o attività antropiche o fattori naturali, in acque di grotta. La sperimentazione è stata sviluppata tramite tecniche microbiologiche classiche e di biologia molecolare (PCR 16S rRNA e PCR-DGGE), finalizzate alla caratterizzazione delle popolazioni microbiche presenti nei diversi siti di prelievo e alla determinazione di loro eventuali variazioni e/o evoluzioni. I valori di carica microbica totale determinati oscillavano da un massimo di 3.32 ad un minimo di 0.18 log UFC/ ml e da un massimo di 2.26 fino a valori al di sotto del limite di determinazione (1 log UFC/ml) per quanto riguarda i coliformi totali e fecali. Le analisi genetiche hanno mostrato la presenza di numerosi specie batteriche (Agrobacterium tumefaciens, Pseudomonas spp., Rahnella aquatilis, Stenotrophomonas maltophilia, Pedobacter swuonensis, Enterobacter spp., Aeromonas hydrophila, Citrobacter, Klebsiella and Raoultella). I microrganismi identificati possono avere diverse origini, alcuni provengono dal terreno, altri possono essere comuni contaminanti delle acque ed altri avere un’origine antropica (batteri fecali). Fino a questo step del progetto, l’analisi PCR-DGGE ha evidenziato le evoluzioni ecologiche, in termine di popolazioni microbiche, presenti tra i diversi campioni e i diversi siti di campionamento all’interno di una stessa grotta.The Project Life + 08NAT/IT/000369 “Gypsum” 2, co-financed by the European Union, has started in the spring of 2010. This project aims to protect and manage the main karst caves and sites of Emilia-Romagna region. The A3 action provides a periodic monitoring of the main karst aquifers in terms of chemistry and microbiology. During the first year and a half, karst waters of 50 control points were analysed (sinking streams, rivers and streams in caves, and resurgences). The objective of this study is to evaluate the impact, in the waters of the cave, of agricultural substances or other forms of pollution or settlements related to human activities or natural factors. The experiment was developed using traditional microbiology techniques and molecular biology techniques (PCR and 16S rRNA PCR-DGGE), focused on the characterization of microbial populations in the different sampling sites and determination of their variations and/or changes. The total microbial concentration ranged from a maxiimum of 3.32 or 2.26 to values below the limit of detection (1 log CFU/ml) for total and faecal colifroms, respectively. The genetic analysis showed the presence of numerous bacterial species (Agrobacterium tumefaciens, Pseudomonas spp., Rahnella aquatilis, Stenotrophomonas maltophilia, Pedobacter swuonensis, Enterobacter spp., Aeromonas hydrophila, Citrobacter, Klebsiella and Raoultella). The organisms identified have different origins, some come from the ground, others are common water contaminants and others derive from human activities (faecal bacteria). Up to now, PCR-DGGE revealed the ecological changes, in terms of microbial populations present in the samples, and different sampling sites within the same cave

    Microparticulate polyelectrolyte complexes for gentamicin transport across intestinal epithelial

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    Polysaccharide microparticles for the oral administration of gentamicin were designed in order to obtainan increased drug absorption by means of microparticle transport across the intestinal epithelia. Alginate/chitosan microparticles with a size of ∼ 2 μm were developed by spray-drying a water solution containingthe drug complexed with the polyanionic alginate and subsequent alginate cross-linking process bycalcium ions and chitosan. The pre-formulation study, performed by changing the concentration of bothcross-linkers, led to the selection of the most suitable formulation which was assayed for its capacity to be translocated across intestinal epithelia, via both M cells contained in Follicle Associated Epithelium (FAE) ofPeyer’s patches and enterocytes of the mucosal epithelium. An ex vivo perfusion technique of rabbit andrat intestinal tissues containing Peyer’s patches combined with an in vitro method by using Caco-2 cellmonolayers demonstrated the microparticulate carrier ability to be taken up by both M cells and enterocytes.However, only the endocytosis by M cells appeared to provide the microparticle transport from theepithelium toward deeper sub-epithelial regions

    Effects of Starter Cultures and Type of Casings on the Microbial Features and Volatile Profile of Fermented Sausages

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    In the literature, the effect of the type of casing on fermented sausages is quite unexplored, while several studies are focused on the impact of starter cultures. Therefore, this paper studied the effect of three commercial starter cultures and two casings (natural or collagen) on Italian fermented sausages. Physico-chemical parameters (aw, pH, weight loss), microbiota, aroma profile and sensory analysis were evaluated. Results showed that collagen casings promoted a higher reduction of pH and weight loss. Concerning the microbiota, samples with natural casing had higher counts of lactic acid bacteria, while yeast proliferation was promoted in those with collagen. Regardless of the starters and casings applied, levels of enterococci and Enterobacteriaceae were low (≤2 log CFU/g). The aroma profile was significantly affected by casing: despite the starter applied, the presence of collagen casing favoured acid accumulation (mainly acetate and butanoate) and reduction of ketones. Sensory analysis highlighted significant differences only for odour, colour intensity and sourness. The differences observed suggest that collagen casings may provide a greater availability of oxygen. Overall, casings rather than starter cultures impact the microbial and sensorial features of fermented sausages

    Eucalyptus essential oil as a natural food preservative: in vivo and in vitro antiyeast potential

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    In this study, the application of eucalyptus essential oil/vapour as beverages preservative is reported. The chemical composition of eucalyptus oil was determined by gas chromatography-mass spectrometry (GC-MS) and solid phase microextraction GC-MS (SPME/GC-MS) analyses. GC-MS revealed that the major constituents were 1,8-cineole (80.5%), limonene (6.5%), \u3b1-pinene (5%), and \u3b3-terpinene (2.9%) while SPME/GC-MS showed a relative reduction of 1,8-cineole (63.9%) and an increase of limonene (13.8%), \u3b1-pinene (8.87%), and \u3b3-terpinene (3.98%). Antimicrobial potential of essential oil was initially determined in vitro against 8 different food spoilage yeasts by disc diffusion, disc volatilization, and microdilution method. The activity of eucalyptus vapours was significantly higher than the eucalyptus oil. Minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) varied from 0.56 to 4.50\u2009mg/mL and from 1.13 to 9\u2009mg/mL, respectively. Subsequently, the combined efficacy of essential oil and thermal treatment were used to evaluate the preservation of a mixed fruit juice in a time-dependent manner. These results suggest eucalyptus oil as a potent inhibitor of food spoilage yeasts not only in vitro but also in a real food system. Currently, this is the first report that uses eucalyptus essential oil for fruit juice preservation against food spoiling yeast
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