65 research outputs found

    Sistema de realitat virtual per entrenament en laparoscopia

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    El proyecto estĂĄ compuesto por un software y un joystick que ayudan a los cirujanos a entrenarse en operaciones de laparoscopia. Se ha desarrollado un programa que rapresente a pantalla una cuerda virtual que se pueda manejar mediante en joystick. Este es el primer modulo de un programa de entrenamiento mas compejo: hasta ahora el cirujano puede manejar y soltar la cuerda de manera realista pero no hay ejercicios implementados aun

    Bacteria Associated to Plants Naturally Selected in a Historical PCB Polluted Soil Show Potential to Sustain Natural Attenuation

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    The exploitation of the association between plants and microorganisms is a promising approach able to boost natural attenuation processes for soil clean-up in vast polluted areas characterized by mixed chemical contamination. We aimed to explore the selection of root-associated bacterial communities driven by different plant species spontaneously established in abandoned agricultural soils within a historical polluted site in north Italy. The site is highly contaminated by chlorinated persistent organic pollutants, mainly constituted by polychlorobiphenyls (PCBs), together with heavy metals and metalloids, in variable concentrations and uneven distribution. The overall structure of the non-vegetated and root-associated soil fractions bacterial communities was described by high-throughput sequencing of the 16S rRNA gene, and a collection of 165 rhizobacterial isolates able to use biphenyl as unique carbon source was assayed for plant growth promotion (PGP) traits and bioremediation potential. The results showed that the recruitment of specific bacterial communities in the root-associated soil fractions was driven by both soil fractions and plant species, explaining 21 and 18% of the total bacterial microbiome variation, respectively. PCR-based detection in the soil metagenome of bacterial bphA gene, encoding for the biphenyl dioxygenase ? subunit, indicated that the soil in the site possesses metabolic traits linked to PCB degradation. Biphenyl-utilizing bacteria isolated from the rhizosphere of the three different plant species showed low phylogenetic diversity and well represented functional traits, in terms of PGP and bioremediation potential. On average, 72% of the strains harbored the bphA gene and/or displayed catechol 2,3-dioxygenase activity, involved in aromatic ring cleavage. PGP traits, including 1-aminocyclopropane-1-carboxylic acid deaminase activity potentially associated to plant stress tolerance induction, were widely distributed among the isolates according to in vitro assays. PGP tested in vivo on tomato plants using eleven selected bacterial isolates, confirmed the promotion and protection potential of the rhizosphere bacteria. Different spontaneous plant species naturally selected in a historical chronically polluted site showed to determine the enrichment of peculiar bacterial communities in the soil fractions associated to the roots. All the rhizosphere communities, nevertheless, hosted bacteria with degradation/detoxification and PGP potential, putatively sustaining the natural attenuation process

    GRB 081007 AND GRB 090424: THE SURROUNDING MEDIUM, OUTFLOWS, AND SUPERNOVAE

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    We discuss the results of the analysis of multi-wavelength data for the afterglows of GRB 081007 and GRB 09042We discuss the results of the analysis of multi-wavelength data for the afterglows of GRB 081007 and GRB 090424, two bursts detected by Swift. One of them, GRB 081007, also shows a spectroscopically confirmed supernova, SN 2008hw, which resembles SN 1998bw in its absorption features, while the maximum magnitude may be fainter, up to 0.7 mag, than observed in SN 1998bw. Bright optical flashes have been detected in both events, which allows us to derive solid constraints on the circumburst-matter density profile. This is particularly interesting in the case of GRB081007, whose afterglow is found to be propagating into a constant-density medium, yielding yet another example of a gamma-ray burst (GRB) clearly associated with a massive star progenitor which did not sculpt the surroundings with its stellar wind. There is no supernova component detected in the afterglow of GRB090424, likely because of the brightness of the host galaxy, comparable to the Milky Way. We show that the afterglow data are consistent with the presence of both forward- and reverse-shock emission powered by relativistic outflows expanding into the interstellar medium. The absence of optical peaks due to the forward shock strongly suggests that the reverse-shock regions should be mildly magnetized. The initial Lorentz factor of outflow of GRB081007 is estimated to be ?? ~ 200, while for GRB090424 a lower limit of ?? > 170 is derived. We also discuss the prompt emission of GRB081007, which consists of just a single pulse. We argue that neither the external forward-shock model nor the shock-breakout model can account for the prompt emission data and suggest that the single-pulse-like prompt emission may be due to magnetic energy dissipation of a Poynting-flux-dominated outflow or to a dissipative photosphere

    The wide-field, multiplexed, spectroscopic facility WEAVE: Survey design, overview, and simulated implementation

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    WEAVE, the new wide-field, massively multiplexed spectroscopic survey facility for the William Herschel Telescope, will see first light in late 2022. WEAVE comprises a new 2-degree field-of-view prime-focus corrector system, a nearly 1000-multiplex fibre positioner, 20 individually deployable 'mini' integral field units (IFUs), and a single large IFU. These fibre systems feed a dual-beam spectrograph covering the wavelength range 366−-959\,nm at R∌5000R\sim5000, or two shorter ranges at R∌20 000R\sim20\,000. After summarising the design and implementation of WEAVE and its data systems, we present the organisation, science drivers and design of a five- to seven-year programme of eight individual surveys to: (i) study our Galaxy's origins by completing Gaia's phase-space information, providing metallicities to its limiting magnitude for ∌\sim3 million stars and detailed abundances for ∌1.5\sim1.5 million brighter field and open-cluster stars; (ii) survey ∌0.4\sim0.4 million Galactic-plane OBA stars, young stellar objects and nearby gas to understand the evolution of young stars and their environments; (iii) perform an extensive spectral survey of white dwarfs; (iv) survey ∌400\sim400 neutral-hydrogen-selected galaxies with the IFUs; (v) study properties and kinematics of stellar populations and ionised gas in z<0.5z<0.5 cluster galaxies; (vi) survey stellar populations and kinematics in ∌25 000\sim25\,000 field galaxies at 0.3â‰Čzâ‰Č0.70.3\lesssim z \lesssim 0.7; (vii) study the cosmic evolution of accretion and star formation using >1>1 million spectra of LOFAR-selected radio sources; (viii) trace structures using intergalactic/circumgalactic gas at z>2z>2. Finally, we describe the WEAVE Operational Rehearsals using the WEAVE Simulator.Comment: 41 pages, 27 figures, accepted for publication by MNRA

    The Lipid Paradox is present in ST-elevation but not in non-ST-elevation myocardial infarction patients:Insights from the Singapore Myocardial Infarction Registry

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    Lowering low-density lipoprotein (LDL-C) and triglyceride (TG) levels form the cornerstone approach of cardiovascular risk reduction, and a higher high-density lipoprotein (HDL-C) is thought to be protective. However, in acute myocardial infarction (AMI) patients, higher admission LDL-C and TG levels have been shown to be associated with better clinical outcomes - termed the 'lipid paradox'. We studied the relationship between lipid profile obtained within 72 hours of presentation, and all-cause mortality (during hospitalization, at 30-days and 12-months), and rehospitalization for heart failure and non-fatal AMI at 12-months in ST-segment elevation myocardial infarction (STEMI) and non-ST-segment elevation myocardial infarction (NSTEMI) patients treated by percutaneous coronary intervention (PCI). We included 11543 STEMI and 8470 NSTEMI patients who underwent PCI in the Singapore Myocardial Infarction Registry between 2008-2015. NSTEMI patients were older (60.3 years vs 57.7 years, p < 0.001) and more likely to be female (22.4% vs 15.0%, p < 0.001). In NSTEMI, a lower LDL-C was paradoxically associated with worse outcomes for death during hospitalization, within 30-days and within 12-months (all p < 0.001), but adjustment eliminated this paradox. In contrast, the paradox for LDL-C persisted for all primary outcomes after adjustment in STEMI. For NSTEMI patients, a lower HDL-C was associated with a higher risk of death during hospitalization but in STEMI patients a lower HDL-C was paradoxically associated with a lower risk of death during hospitalization. For this endpoint, the interaction term for HDL-C and type of MI was significant even after adjustment. An elevated TG level was not protective after adjustment. These observations may be due to differing characteristics and underlying pathophysiological mechanisms in NSTEMI and STEMI

    Sistema de realitat virtual per entrenament en laparoscopia

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    El proyecto estĂĄ compuesto por un software y un joystick que ayudan a los cirujanos a entrenarse en operaciones de laparoscopia. Se ha desarrollado un programa que rapresente a pantalla una cuerda virtual que se pueda manejar mediante en joystick. Este es el primer modulo de un programa de entrenamiento mas compejo: hasta ahora el cirujano puede manejar y soltar la cuerda de manera realista pero no hay ejercicios implementados aun

    A First Application of Collaborative Learning In Particle Physics

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    Abstract Over the last ten years, the popularity of Machine Learning (ML) has grown exponentially in all scientific fields, including particle physics. The industry has also developed new powerful tools that, imported into academia, could revolutionise research. One recent industry development that has not yet come to the attention of the particle physics community is Collaborative Learning (CL), a framework that allows training the same ML model with different datasets. This work explores the potential of CL, testing the library Colearn with neutrino physics simulation. Colearn, developed by the British Cambridge-based firm Fetch.AI, enables decentralised machine learning tasks. Being a blockchain-mediated CL system, it allows multiple stakeholders to build a shared ML model without needing to rely on a central authority. A generic Liquid Argon Time-Projection Chamber (LArTPC) has been simulated and images produced by fictitious neutrino interactions have been used to produce several datasets. These datasets, called learners, participated successfully in training a Deep Learning (DL) Keras model using blockchain technologies in a decentralised way. This test explores the feasibility of training a single ML model using different simulation datasets coming from different research groups. In this work, we also discuss a framework that instead makes different ML models compete against each other on the same dataset. The final goal is then to train the most performant ML model across the entire scientific community for a given experiment, either using all of the datasets available or selecting the model which performs best among every model developed in the community.</jats:p
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