1,227 research outputs found

    Gribov ambiguity and degenerate systems

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    The relation between Gribov ambiguity and degeneracies in the symplectic structure of physical systems is analyzed. It is shown that, in finite-dimensional systems, the presence of Gribov ambiguities in regular constrained systems (those where the constraints are functionally independent) always leads to a degenerate symplectic structure upon Dirac reduction. The implications for the Gribov-Zwanziger approach to QCD are discussed.Comment: 26 pages, 6 figures. Comments and references adde

    Economia agraria e pianificazione economica territoriale nel Parco nazionale del Sagarmatha (Everest, Nepal)

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    In questo quaderno vengono pubblicati i contributi scientifici che sono stati presentati alla conferenza nazionale avente per tema “Economia agraria e pianificazione economica territoriale nel Parco Nazionale del Sagarmatha (Everest, Nepal)”, che si è tenuta alla facoltà di Economia dell’Università degli Studi di Perugia, il 25 e 26 settembre 2008. English: This paper collects research works presented at a national conference on the theme "Agricultural Economy, Environmental Economics and Land Use Planning in the Sagarmatha National Park (Everest, Nepal)" held at the Faculty of Economics of the University of Perugia, September, 25th-26th, 2008economia agraria, gestione ambientale, parco naturale, pianificazione economica territoriale, sviluppo economico sostenibile, Sagarmatha National Park

    Updated analysis of the dynamical relation between asteroid 2003 EH1 and comets C/1490 Y1 and C/1385 U1

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    The asteroid 2003 EH1, proposed as the parent body of the Quadrantid meteor shower, is thought to be the remnant of a past cometary object, tentatively identified with the historical comets C/1490 Y1 and C/1385 U1. In the present work we use recovery astrometry to extend the observed arc of 2003 EH1 from 10 months to about 5 years, enough to exclude the proposed direct relationship of the asteroid with both of the comets.Comment: Submitted to Monthly Notices of the RAS Letters Updated with a new table and other minor change

    Susceptibility to Stress Corrosion Cracking of 254SMO SS

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    The susceptibility to stress corrosion cracking (SCC) of solubilized and sensitized 254SMO SS was studied in sodium chloride, and sodium fluoride solutions at 80 °C and sulfuric acid solutions in presence of sodium chloride at 25 °C. The influence of salt concentration, pH values and the addition of thiosulfate was examined. The susceptibility to SCC was evaluated by Slow Strain Rate Tests (SSRT), at 1.5 x 10-6 s-1 strain rate. The behavior of 254SMO was compared to those of AISI 316L SS and Hastelloy C276. 254SMO showed an excellent resistance to SCC in all conditions, except in the more acidic solutions (pH <= 1) where, in the sensitized conditions, intergranular stress corrosion cracking occurred

    Carbonic anhydrase inhibition for the management of cerebral ischemia: in vivo evaluation of sulfonamide and coumarin inhibitors.

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    Ischemia of brain areas is a global health problem, causing death or long-term disability. Current pharmacological options have limited impact on ischemic damages. Recently, a relationship between hypoxia and carbonic anhydrase (CA) over-expression has been highlighted suggesting CA inhibition as a possible target. This study aimed to evaluate the pharmacological profile of sulfonamide and coumarin CA inhibitors in rats underwent permanent middle cerebral artery occlusion (pMCAO). The neurological score of pMCAO rats was dramatically reduced 24 h after occlusion. Repeated subcutaneous injections of the CA inhibitors 4 and 7 (1 mg kg(-1)) were able to increase the neurological score by 40%. Compound 7 showed the tendency to reduce the volume of hemisphere infarction. The standard CA inhibitor acetazolamide was ineffective. The properties of novel CA inhibitors to improve neurological functionalities after cerebral ischemic insult are shown. The CA involvement in cerebral hypoxic phenomena deserves deeper investigations

    First-in-Class Dual Hybrid Carbonic Anhydrase Inhibitors and Transient Receptor Potential Vanilloid 1 Agonists Revert Oxaliplatin-Induced Neuropathy

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    Here, we report for the first time a series of compounds potentially useful for the management of oxaliplatin-induced neuropathy (OINP) able to modulate the human Carbonic Anhydrases (hCAs) as well as the Transient Receptor Potential Vanilloid 1 (TRPV1). All compounds showed effective in vitro inhibition activity toward the main hCAs involved in such a pathology, whereas selected items reported moderate agonism of TRPV1. X-ray crystallographic experiments assessed the binding modes of the two enantiomers (R)-37a and (S)-37b within the hCA II cleft. Although the tails assumed diverse orientations, no appreciable effects were observed for their hCA II affinity. Similarly, the activity of (R)-39a and (S)-39b on TRPV1 was not influenced by the stereocenters. In vivo evaluation of the most promising derivatives (R)-12a, (R)-37a, and the two enantiomers (R)-39a, (S)-39b revealed antihypersensitivity effects in a mouse model of OINP with potent and persistent effect up to 75 min after administration

    Phaseolus vulgaris extract ameliorates high-fat diet-induced colonic barrier dysfunction and inflammation in mice by regulating peroxisome proliferator-activated receptor expression and butyrate levels

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    Obesity is a health concern worldwide, and its onset is multifactorial. In addition to metabolic syndrome, a high-fat diet induces many deleterious downstream effects, such as chronic systemic inflammation, a loss of gut barrier integrity, and gut microbial dysbiosis, with a reduction of many butyrate-producing bacteria. These conditions can be ameliorated by increasing legumes in the daily diet. White and kidney beans (Phaseolus vulgaris L.) and their non-nutritive bioactive component phaseolamin were demonstrated to mitigate several pathological features related to a metabolic syndrome-like condition. The aim of the present study was to investigate the molecular pathways involved in the protective effects on the intestinal and liver environment of a chronic oral treatment with P. vulgaris extract (PHAS) on a murine model of the high-fat diet. Results show that PHAS treatment has an anti-inflammatory effect on the liver, colon, and cecum. This protective effect was mediated by peroxisome proliferator-activated receptor (PPAR)-α and γ. Moreover, we also observed that repeated PHAS treatment was able to restore tight junctions' expression and protective factors of colon and cecum integrity disrupted in HFD mice. This improvement was correlated with a significant increase of butyrate levels in serum and fecal samples compared to the HFD group. These data underline that prolonged treatment with PHAS significantly reduces some pathological features related to the metabolic syndrome-like condition, such as inflammation and intestinal barrier disruption; therefore, PHAS could be a valid tool to be associated with the therapeutic strategy

    Thermal Balancing Policy for Streaming Computing on Multiprocessor Architectures

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    As feature sizes decrease, power dissipation and heat generation density exponentially increase. Thus, temperature gradients in Multiprocessor Systems on Chip (MPSoCs) can seriously impact system performance and reliability. Thermal balancing policies based on task migration have been proposed to modulate power distribution between processing cores to achieve temperature flattening. However, in the context of MPSoC for multimedia streaming computing, where timeliness is critical, the impact of migration on quality of service must be carefully analyzed. In this paper we present the design and implementation of a lightweight thermal balancing policy that reduces on-chip temperature gradients via task migration. This policy exploits run-time temperature and load information to balance the chip temperature. Moreover, we assess the effectiveness of the proposed policy for streaming computing architectures by analyzing deadlines misses and architectural thermal effects of task migration using a cycle-accurate thermal-aware emulation infrastructure. Our results using a real-life software defined radio multitask benchmark show that our policy achieves thermal balancing while keeping migration costs bounded

    NeuroBench:A Framework for Benchmarking Neuromorphic Computing Algorithms and Systems

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    Neuromorphic computing shows promise for advancing computing efficiency and capabilities of AI applications using brain-inspired principles. However, the neuromorphic research field currently lacks standardized benchmarks, making it difficult to accurately measure technological advancements, compare performance with conventional methods, and identify promising future research directions. Prior neuromorphic computing benchmark efforts have not seen widespread adoption due to a lack of inclusive, actionable, and iterative benchmark design and guidelines. To address these shortcomings, we present NeuroBench: a benchmark framework for neuromorphic computing algorithms and systems. NeuroBench is a collaboratively-designed effort from an open community of nearly 100 co-authors across over 50 institutions in industry and academia, aiming to provide a representative structure for standardizing the evaluation of neuromorphic approaches. The NeuroBench framework introduces a common set of tools and systematic methodology for inclusive benchmark measurement, delivering an objective reference framework for quantifying neuromorphic approaches in both hardware-independent (algorithm track) and hardware-dependent (system track) settings. In this article, we present initial performance baselines across various model architectures on the algorithm track and outline the system track benchmark tasks and guidelines. NeuroBench is intended to continually expand its benchmarks and features to foster and track the progress made by the research community
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