2,280 research outputs found

    A blockchain-based Decentralized System for proper handling of temporary Employment contracts

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    Temporary work is an employment situation useful and suitable in all occasions in which business needs to adjust more easily and quickly to workload fluctuations or maintain staffing flexibility. Temporary workers play therefore an important role in many companies, but this kind of activity is subject to a special form of legal protections and many aspects and risks must be taken into account both employers and employees. In this work we propose a blockchain-based system that aims to ensure respect for the rights for all actors involved in a temporary employment, in order to provide employees with the fair and legal remuneration (including taxes) of work performances and a protection in the case employer becomes insolvent. At the same time, our system wants to assist the employer in processing contracts with a fully automated and fast procedure. To resolve these problems we propose the D-ES (Decentralized Employment System). We first model the employment relationship as a state system. Then we describe the enabling technology that makes us able to realize the D-ES. In facts, we propose the implementation of a DLT (Decentralized Ledger Technology) based system, consisting in a blockchain system and of a web-based environment. Thanks the decentralized application platforms that makes us able to develop smart contracts, we define a discrete event control system that works inside the blockchain. In addition, we discuss the temporary work in agriculture as a interesting case of study.Comment: Accepted for publication in the proceedings of the "Computing Conference 2018" - 10-12 July 2018 - London, United Kingdo

    Ressenyes

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    Index de les obres ressenyades: MercĂš RODOREDA, Sa Pratza de su Diamant

    Articles a l'Alguer

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    Colonizzazione sabauda e diaspora greca, Giampaolo Salice, Sette CittĂ , Viterbo

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    Il lavoro di Giampaolo Salice, nelle sua densitĂ  e complessitĂ , si presta a letture polisemiche partendo giĂ  dall’interessante introduzione in cui cerca di “afferrare” il concetto sfuggente di diaspora. La riflessione sul significato di diaspora Ăš portata avanti sulla base dell’imponente ricerca bibliografica condotta dall’autore: dalle origini greche del termine, passando per le definizioni di William Safran, Robin Cohen, James Clifford e Brian Keith Axel1. Le comunitĂ  diasporiche sono multi-centriche, legate piĂč o meno debolmente al luogo d’origine (fisico o mitologico) in perenne movimento e connesse a un network. Riportando un concetto di Miguel Mellino, Salice scrive: «In un mondo digitalmente interconnesso, comprendere i fenomeni diasporici Ăš necessitĂ  non solo degli scienziati sociali, ma anche delle masse di individui che sperimentano un sentimento di connessione a una vicenda collettiva di sradicamento, la quale sembra resistere all’erosione del dimenticare, dell’assimilare, dell’allontanare»2. Il tema si presta dunque a letture sia storiche sia d’attualitĂ : le complessitĂ  diasporiche saranno oggetto di riflessione e discussione anche nel futuro prossimo, considerati i recenti eventi mondiali

    An aminoacyl-tRNA synthetase:elongation factor complex for substrate channeling in archaeal translation

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    Translation requires the specific attachment of amino acids to tRNAs by aminoacyl-tRNA synthetases (aaRSs) and the subsequent delivery of aminoacyl-tRNAs to the ribosome by elongation factor 1 alpha (EF-1α). Interactions between EF-1α and various aaRSs have been described in eukaryotes, but the role of these complexes remains unclear. To investigate possible interactions between EF-1α and other cellular components, a yeast two-hybrid screen was performed for the archaeon Methanothermobacter thermautotrophicus. EF-1α was found to form a stable complex with leucyl-tRNA synthetase (LeuRS; KD = 0.7 ÎŒM). Complex formation had little effect on EF-1α activity, but increased the kcat for Leu-tRNALeu synthesis ∌8-fold. In addition, EF-1α co-purified with the archaeal multi-synthetase complex (MSC) comprised of LeuRS, LysRS and ProRS, suggesting the existence of a larger aaRS:EF-1α complex in archaea. These interactions between EF-1α and the archaeal MSC contribute to translational fidelity both by enhancing the aminoacylation efficiencies of the three aaRSs in the complex and by coupling two stages of translation: aminoacylation of cognate tRNAs and their subsequent channeling to the ribosome

    Monitoring Lys-tRNA\u3csup\u3eLys\u3c/sup\u3e Phosphatidylglycerol Transferase Activity

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    In some bacteria Lys-tRNALys is used both in translation and for the specific addition of Lys to phosphatidylglycerol in the cytoplasmic membrane. This reaction is catalyzed by the membrane protein MprF, and the lysyl-phosphatidylglycerol formed contributes to the resistance of these bacteria to various cationic antibacterial molecules. Obtaining proteins and reconstituting an in vitro system mimicking membrane conditions is a major challenge to studying the function of membrane proteins, especially when labile substrates such as Lys-tRNALys are required. Here we report methods to obtain a stable enriched membrane fraction containing MprF, and the techniques necessary to quantitatively monitor its activity in vitro and in vivo

    Transfer RNA Comes of Age

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    The year the journal RNA was founded was slated by some in scientific publishing to be the year that one particular type of RNA\u27s run in the spotlight would end. In 1995 I had recently started as a post-doc with Dieter Söll at Yale when he came into the lab to solemnly inform us all that an editor at a certain (S)cience journal had just told him “we won\u27t be publishing any more tRNA papers.” For a post-doc who had migrated across the Atlantic for the sole purpose of furthering his career by working on tRNA this was not great news, but at least the pizza was as good as promised in New Haven (if you need convincing, try the Italian and Veggie Bombs at Modern Apizza on State Street). Dieter consoled us by saying that plenty of other good journals were still interested in tRNA, plus there was this

    The Pros of Changing tRNA Identity

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    The notion that errors in protein synthesis are universally harmful to the cell has been questioned by findings that suggest such mistakes may sometimes be beneficial. However, how often these beneficial mistakes arise from programmed changes in gene expression as opposed to reduced accuracy of the translation machinery is still unclear. A new study published in JBC shows that some bacteria have beneficially evolved the ability to mistranslate specific parts of the genetic code, a trait that allows improved antibiotic resistance

    Effetti dell'allenamento intermittente breve ad alta intensitĂ  e delle ripetute aerobiche sul Test Repeated Sprint Ability in giovani calciatori d'elite

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    The purpose of this study is to evaluate the effects of two different training methods: the repeated aerobic bouts and the short intermittent high intensity workout on the ability to carry out repeated sprint bouts RSA in a group of young soccer players and also to determine the impact of training on aerobic and neuromuscular performances. Twenty-Four (24) male soccer players have been assessed and trained, all of them partecipating regularly in the 2013-2014 season at the National Championship "Professional Development Phase" (Allievi Professionisti) with Cagliari Calcio SPA Football Club. Hereinafter the anthropometric characteristics of the sample tested: 16.33 ± 0.49 years, height 175 ± 6.3, 65.8 ± 6.8 weight. The 24 athletes were randomly included into two working groups: intermittent training group (HI. No. 12) and repeated aerobic exercise group (R. Aer. No. 12). Players underwent two separate sessions of evaluation tests. During the first session, in the morning, the players performed the vertical jump test (CMJ) with no counter movement (SJ). In the afternoon session the repeated sprint bouts were carried out (RSA). Finally the next day the athletes underwent the tests for the aerobic power (V.BILLAT). The results regarding the Aerobic Group (R. Aer.) were respectively SJ and CMJ at T0 36,95 ± 4,03cm; 37,44 ± 4,09cm; T1 to 37.99 ± 3.69 cm; 38.63 ± 3.96 cm; in the RSA tests we obtained the following T0 and T1 values respectively: 7.690 ± 0.12 s; 7,585 ± 0,11s; The Billat test instead highlighted the following values ± 1506 67,26m; 1596.6 ± 64,95m. The results regarding the Intermittent (HI) group were respectively SJ and CMJ at T0 36,69 ± 4,99cm; 37,98 ± 3,97cm; T1 to 38.15 ± 4.79 cm; 39.79 ± 3.78 cm; in the RSA tests we obtained the following T0 and T1 values respectively: 7.64 ± 0.11 s; 7.31 ± 0,11s; The Billat test instead highlighted the following values: 1537.3 ± 77,70m; 1627.1 ± 72,29m. The results indicate one or more variations of the investigated capacities between pre and post workout within the same group, and also suggest that by comparing the two methods, intermittent and repeated aerobic, the first of the two was more effective. The lack of a statistically significant difference on the capacity of aerobic performance evaluated through the Billat test suggests that both protocols have their validity in improving this component. While as regards the RSA test a statistically significant change was detected in favor of the intermittent protocol with respect to the repeated aerobic bouts. This variation was found through the reduction of the average execution time of the RSA test. Another result emerged from the statistical analysis is that both training protocols had no negative effects on neuromuscular skills assessed through the vertical jump test of the SJ and CMJ, this in agreement with what was found in previous studies such as Mc Millan (2005) and Ferrari (2007), in which training protocols for the aerobic performance of the player very similar to those used in this study were carried out. In conclusion the study indicated that the short high intensity intermittent method has proved more powerful than the Repeated Sprint Ability Test (RSA), which is indicated by most researchers as a key skill in football performance: we believe it respects mostly the kinematic analogies of the game, accelerations, decelerations and postural situations with minor variations of the bust concerning the various stages of the player's running (Paradisis GP. e coll. 2001) by an increased recruitment of the fast fibers in the rapid typical accelerations/decelerations of this sport. Furthermore we are inclined to hypothesize that this research reshapes the use of bioenergetic systems, already studied by (Dawson B. and coll. 1998), (to Ross, et al. 2001), it all along with the possibility of repeating the sprint at a high intensity with partial recoveries while maintaining a high quality and the considerable advantage, being soccer a situational sport, to help keep up a greater lucidity from a cognitive point of view and theoretically to select more logical and tactically effective choices
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