3,885 research outputs found

    Motion estimation and CABAC VLSI co-processors for real-time high-quality H.264/AVC video coding

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    Real-time and high-quality video coding is gaining a wide interest in the research and industrial community for different applications. H.264/AVC, a recent standard for high performance video coding, can be successfully exploited in several scenarios including digital video broadcasting, high-definition TV and DVD-based systems, which require to sustain up to tens of Mbits/s. To that purpose this paper proposes optimized architectures for H.264/AVC most critical tasks, Motion estimation and context adaptive binary arithmetic coding. Post synthesis results on sub-micron CMOS standard-cells technologies show that the proposed architectures can actually process in real-time 720 × 480 video sequences at 30 frames/s and grant more than 50 Mbits/s. The achieved circuit complexity and power consumption budgets are suitable for their integration in complex VLSI multimedia systems based either on AHB bus centric on-chip communication system or on novel Network-on-Chip (NoC) infrastructures for MPSoC (Multi-Processor System on Chip

    Combined GW and dynamical mean field theory: Dynamical screening effects in transition metal oxides

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    We present the first dynamical implementation of the combined GW and dynamical mean field scheme ("GW+DMFT") for first principles calculations of the electronic properties of correlated materials. The application to the ternary transition metal oxide SrVO3 demonstrates that this schemes inherits the virtues of its two parent theories: a good description of the local low energy correlation physics encoded in a renormalized quasi-particle band structure, spectral weight transfer to Hubbard bands, and the physics of screening driven by long-range Coulomb interactions. Our data is in good agreement with available photoemission and inverse photoemission spectra; our analysis leads to a reinterpretation of the commonly accepted "three-peak structure" as originating from orbital effects rather than from the electron addition peak within the t2g manifold.Comment: replaced with published version (6 pages, 3 figures); first version was submitted to PRL on June 19, 201

    General models of Einstein gravity with a non-Newtonian weak-field limit

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    We investigate Einstein theories of gravity, coupled to a scalar field \vphi and point-like matter, which are characterized by a scalar field-dependent matter coupling function e^{H(\vphi)}. We show that under mild constraints on the form of the potential for the scalar field, there are a broad class of Einstein-like gravity models -characterized by the asymptotic behavior of H- which allow for a non-Newtonian weak-field limit with the gravitational potential behaving for large distances as ln r. The Newtonian term GM/r appears only as sub-leading. We point out that this behavior is also shared by gravity models described by f(R) Lagrangians. The relevance of our results for the building of infrared modified theories of gravity and for modified Newtonian dynamics is also discussed.Comment: 9 page

    Linear behavior of the optical conductivity and incoherent charge transport in BaCoS2

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    Optical conductivity measurements on a BaCoS2 single crystal show an unusual linear behavior over a broad spectral range. In the paramagnetic phase above 300 K, the spectrum shows no gap, which contradicts the previously proposed scenario of a charge-transfer Mott insulator. Ab initio dynamical mean field theory calculations including a retarded Hubbard interaction explain the data in terms of an incipient opening of a Co(3d)-S(3p) charge-transfer gap concomitant to incoherent charge transport driven by electronic correlations. These results point to a non-Fermi liquid scenario with Hund's metal properties in the paramagnetic state, which arises from an incipient Mott phase destabilized by low-energy charge fluctuations across the vanishing 3d-3p charge-transfer gap.Comment: 7 pages, 5 figure

    Familial hypercholesterolemia: The Italian Atherosclerosis Society Network (LIPIGEN)

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    Primary dyslipidemias are a heterogeneous group of disorders characterized by abnormal levels of circulating lipoproteins. Among them, familial hypercholesterolemia is the most common lipid disorder that predisposes for premature cardiovascular disease. We set up an Italian nationwide network aimed at facilitating the clinical and genetic diagnosis of genetic dyslipidemias named LIPIGEN (LIpid TransPort Disorders Italian GEnetic Network)

    Dynamical correlations and screened exchange on the experimental bench: spectral properties of the cobalt pnictide BaCo2As2

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    Understanding the Fermi surface and low-energy excitations of iron or cobalt pnictides is crucial for assessing electronic instabilities such as magnetic or superconducting states. Here, we propose and implement a new approach to compute the low-energy properties of correlated electron materials, taking into account both screened exchange beyond the local density approximation and local dynamical correlations. The scheme allows us to resolve the puzzle of BaCo2As2, for which standard electronic structure techniques predict a ferromagnetic instability not observed in nature.Comment: 6 pages, 4 figures + Supplementary materia

    Low-energy models for correlated materials: bandwidth renormalization from Coulombic screening

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    We provide a prescription for constructing Hamiltonians representing the low energy physics of correlated electron materials with dynamically screened Coulomb interactions. The key feature is a renormalization of the hopping and hybridization parameters by the processes that lead to the dynamical screening. The renormalization is shown to be non-negligible for various classes of correlated electron materials. The bandwidth reduction effect is necessary for connecting models to materials behavior and for making quantitative predictions for low-energy properties of solids.Comment: 4 pages, 2 figure

    Efficacy of non-surgical periodontal therapy in reducing periodontal indexes in kidney-transplant patients

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    Efficacy of non-surgical periodontal therapy in reducing periodontal indexes in kidney-transplant patients. I. Casula, L. Zanardini*, M. Bianchi, V. Spotti, E. Marchesini Department of Medical and Surgical Specialties and Public Health Dentale - Dental School – University of Brescia, Italy Aim: kidney-transplant patient must take cyclosporine-A and calcium channel blockers chronically. Both medicines involve a gingival overgrowth (G.O.) as a collateral effect and this is due to their dosage: it appears 1-3 months after the beginning of the therapy. The prevalence of the G.O. is 84%. The G.O. originates from anterior interdental papilla and it appears as a red and soft tumefaction, that becomes more fibrinous as time goes by. The G.O. takes place in apical-coronal verse and also in vestibular-lingual verse and it looks like a gingival hypertrophy and hyperplasia, which is due to an abnormal increase of the number of fibroblasts into gingival connective tissue. The G.O. involves a great aggregation of extracellular Matrix, or less degradation of it, or both these processes simultaneously. The G.O. leads to the formation of pseudopockets, which interfere with the correct oral hygiene practices. This condition gives rise to mature plaque retention , that leads to infection, inflammation and the increase of the G.O. This condition becomes worse because of bad pre-transplant oral hygiene state. The aim of this study is to estimate the efficacy of non-surgical periodontal therapy in reducing the G.O. in kidney-transplant patient. Materials and methods: a sample of 32 simple random kidney transplant subjects was enrolled in this study (mean age: 58,44; range: 33-81, 21 m., 11f.). All of them were taking cyclosporine A and calcium channel blockers. Patients taking idantoine, pregnant women, patients suffering from diabetes mellitus or people who have undergone gingival surgery were excluded. The study started on November 2012 and finished on September 2013. Periodontal indexes and Professional oral hygiene practices were performed by the same dental hygienist. The plaque, calculus, bleeding, G.O. and probing depth indexes were evaluated at T0, T1, T2, T3 (at 0, 2, 4, 6 months respectively). Every time the same oral hygiene protocol was applied: non-surgical periodontal therapy with ultrasonic instruments above and below the gum. Results: 787 teeth analysed and 4722 periodontal sites probed. Plaque index (PI), calculus index (CI) and bleeding index (BoP) show significant statistical reduction (p<0,0001). T-test was used for statistic analysis. PI at T0=82,09%, at T3=29,89%/ CI at T0=53,44%, at T3=23,70%/ BoP at T0=71,98%, at T3=26,18%. Probing depth (PD), at six-monthly control , shows a significant statistical reduction (p<0,0001). PD 1-3 mm at T0=16,58%, at T3=30,45%. PD 4-6mm at T0=74,06%, at T3=64,70%. PD 7-9 mm at T0=9,36%, at T3=4,85%. G.O. At T0=54,93%, at T3=44,98%, with a significant statistical reduction (p<0,0001). Conclusions: the applied oral hygiene protocol is simple but effective in reducing drug-induced gingival overgrowth in kidney-transplant patient taking Cyclosporine-A. These clinic results assure a better oral health, improving the quality of life form an aesthetic and functional point of view

    Alcuni esempi di catalogazione e restauro nell’ambito della Collezione Storica degli Strumenti di Fisica dell’Università di Palermo

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    In questo articolo presenteremo e discuteremo della catalogazione e restauro e di alcuni strumenti scientifici di particolare interesse storico-didattico appartenenti alla Collezione Storica degli Strumenti di Fisica dell’Università di Palermo. La catalogazione è stata effettuata secondo le indicazioni fornite dell’Istituto Centrale per il Catalogo e la Documentazione, per mezzo della scheda per il patrimonio scientifico-tecnologico. Nell’articolo saranno discussi gli aspetti tecnici degli interventi di restauro effettuati e saranno indicate le linee guida generali per il proseguimento dell’attività avviata.The article deals with the cataloguing and restoration of some scientific instruments of particular historical and didactic interest belonging to the Historical Collection of the Physics Instruments of the University of Palermo. The restoration activities have been carried out side by side the cataloguing, which has been done following the instructions supplied by the Central Institute for Cataloguing and Documentation with the official form for the scientific and technological heritage. In the article, we will discuss the technical aspects of the work carried out and basic guidelines will be given for the continuation of the activity
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