319 research outputs found

    Packing Rates Of Measures And A Conjecture For The Packing Density Of 2413

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    We give a new lower bound of 0.10472422757673209041 for the packing density of 2413, justify it by a construction, and conjecture that this value is actually equal to the packing density. Along the way we define the packing rate of a permutation with respect to a measure, and show that maximizing the packing rate of a pattern over all measures gives the packing density of the pattern

    Stationary States in Infinite Volume with Non-zero Current

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    We study the Ginzburg\u2013Landau stochastic models in infinite domains with some special geometry and prove that without the help of external forces there are stationary measures with non-zero current in three or more dimensions

    The Secret Garden of Neuronal circRNAs

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    High-throughput transcriptomic profiling approaches have revealed that circular RNAs (circRNAs) are important transcriptional gene products, identified across a broad range of organisms throughout the eukaryotic tree of life. In the nervous system, they are particularly abundant, developmentally regulated, region-specific, and enriched in genes for neuronal proteins and synaptic factors. These features suggested that circRNAs are key components of an important layer of neuronal gene expression regulation, with known and anticipated functions. Here, we review major recognized aspects of circRNA biogenesis, metabolism and biological activities, examining potential new functions in the context of the nervous system

    Identification of a regulated pathway for nuclear pre-mRNA turnover

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    We have identified a nuclear pathway that rapidly degrades unspliced pre-mRNAs in yeast. This involves 3′→5′ degradation by the exosome complex and 5′→3′ degradation by the exonuclease Rat1p. 3′→5′ degradation is normally the major pathway and is regulated in response to carbon source. Inhibition of pre-mRNA degradation resulted in increased levels of pre-mRNAs and spliced mRNAs. When splicing was inhibited by mutation of a splicing factor, inhibition of turnover resulted in 20- to 50-fold accumulation of pre-mRNAs, accompanied by increased mRNA production. Splicing of a reporter construct with a 3′ splice site mutation was also increased on inhibition of turnover, showing competition between degradation and splicing. We propose that nuclear pre-mRNA turnover represents a novel step in the regulation of gene expression

    Use of Foley catheter in control of internal carotid hemorrhage during endoscopic endonasal surgery

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    Internal carotid artery (ICA) injuries during endoscopic endonasal surgery (EES) are rare life-threatening events. We describe a technique to manage ICA injuries based on the use of Foley catheters.A 26-year-old female underwent endoscopic transnasal trans-sphenoidal removal of pituitary adenoma. Cerebrospinal fluid leak occurred 4 days postoperatively. During repair procedure, accidental injury of ICA occurred. Emergency nasal packing through positioning of four Foley urologic catheters was successfully performed to stop bleeding. The patient did not report neurologic deficits.In author's opinion, Foley catheters are suitable to obtain immediate bleeding control since they are rapidly available and easily usable

    ArCo: the Italian Cultural Heritage Knowledge Graph

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    ArCo is the Italian Cultural Heritage knowledge graph, consisting of a network of seven vocabularies and 169 million triples about 820 thousand cultural entities. It is distributed jointly with a SPARQL endpoint, a software for converting catalogue records to RDF, and a rich suite of documentation material (testing, evaluation, how-to, examples, etc.). ArCo is based on the official General Catalogue of the Italian Ministry of Cultural Heritage and Activities (MiBAC) - and its associated encoding regulations - which collects and validates the catalogue records of (ideally) all Italian Cultural Heritage properties (excluding libraries and archives), contributed by CH administrators from all over Italy. We present its structure, design methods and tools, its growing community, and delineate its importance, quality, and impact

    Precision Timing with shower maximum detectors based on pixelated micro-channel plates

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    Future calorimeters and shower maximum detectors at high luminosity colliders need to be highly radiation resistant and very fast. One exciting option for such a detector is a calorimeter composed of a secondary emitter as the active element. In this report we outline the study and development of a secondary emission calorimeter prototype using micro-channel plates (MCP) as the active element, which directly amplify the electromagnetic shower signal. We demonstrate the feasibility of using a bare MCP within an inexpensive and robust housing without the need for any photo cathode, which is a key requirement for high radiation tolerance. Test beam measurements of the prototype were performed with 120 GeV primary protons and secondary beams at the Fermilab Test Beam Facility, demonstrating basic calorimetric measurements and precision timing capabilities. Using multiple pixel readout on the MCP, we demonstrate a transverse spatial resolution of 0.8 mm, and time resolution better than 40 ps for electromagnetic showers

    Droplet minimizers for the Gates-Lebowitz-Penrose free energy functional

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    We study the structure of the constrained minimizers of the Gates-Lebowitz-Penrose free-energy functional FGLP(m){\mathcal F}_{\rm GLP}(m), non-local functional of a density field m(x)m(x), xTLx\in {\mathcal T}_L, a dd-dimensional torus of side length LL. At low temperatures, FGLP{\mathcal F}_{\rm GLP} is not convex, and has two distinct global minimizers, corresponding to two equilibrium states. Here we constrain the average density L^{-d}\int_{{\cal T}_L}m(x)\dd x to be a fixed value nn between the densities in the two equilibrium states, but close to the low density equilibrium value. In this case, a "droplet" of the high density phase may or may not form in a background of the low density phase, depending on the values nn and LL. We determine the critical density for droplet formation, and the nature of the droplet, as a function of nn and LL. The relation between the free energy and the large deviations functional for a particle model with long-range Kac potentials, proven in some cases, and expected to be true in general, then provides information on the structure of typical microscopic configurations of the Gibbs measure when the range of the Kac potential is large enough

    Upscaled phase-field models for interfacial dynamics in strongly heterogeneous domains

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    We derive a new effective macroscopic Cahn-Hilliard equation whose homogeneous free energy is represented by 4-th order polynomials, which form the frequently applied double-well potential. This upscaling is done for perforated/strongly het- erogeneous domains. To the best knowledge of the authors, this seems to be the first attempt of upscaling the Cahn-Hilliard equation in such domains. The new homog- enized equation should have a broad range of applicability due to the well-known versatility of phase-field models. The additionally introduced feature of systemati- cally and reliably accounting for confined geometries by homogenization allows for new modeling and numerical perspectives in both, science and engineering. Our results are applied to wetting dynamics in porous media and to a single channel with strongly heterogeneous walls

    TIMI, GRACE and alternative risk scores in Acute Coronary Syndromes: A meta-analysis of 40 derivation studies on 216,552 patients and of 42 validation studies on 31,625 patients.

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    BACKGROUND: Acute coronary syndromes (ACS) represent a difficult challenge for physicians. Risk scores have become the cornerstone in clinical and interventional decision making. METHODS AND RESULTS: PubMed was systematically searched for ACS risk score studies. They were divided into ACS studies (evaluating Unstable Angina; UA, Non ST Segment Elevation Myocardial Infarction; NSTEMI, and ST Segment Elevation Myocardial Infarction; STEMI), UA/NSTEMI studies or STEMI studies. The c-statistics of validation studies were pooled when appropriate with random-effect methods. 7 derivation studies with 25,525 ACS patients and 15 validation studies including 257,654 people were formally appraised. Pooled analysis of GRACE scores, both at short (0.82; 0.80-0.89 I.C 95%) and long term follow up (0.84; 0.82-0.87; I.C 95%) showed the best performance, with similar results to Simple Risk Index (SRI) derivation cohorts at short term. For NSTEMI/UA, 18 derivation studies with 56,560 patients and 18 validation cohorts with 56,673 patients were included. Pooled analysis of validations studies showed c-statistics of 0.54 (95% CI = 0.52-0.57) and 0.67 (95% CI = 0.62-0.71) for short and long term TIMI validation studies, and 0.83 (95% CI = 0.79-9.87) and 0.80 (95% CI = 0.74-0.89) for short and long term GRACE studies. For STEMI, 15 studies with 134,557 patients with derivation scores, and 17 validation studies with 187,619 patients showed a pooled c-statistic of 0.77 (95% CI = 0.71-0.83) and 0.77 (95% CI = 0.72-0.85) for TIMI at short and long term, and a pooled c-statistic of 0.82 (95% CI = 0.81-0.83) and 0.81 (95% CI = 0.80-0.82) for GRACE at short and long terms respectively. CONCLUSIONS: TIMI and GRACE are the risk scores that up until now have been most extensively investigated, with GRACE performing better. There are other potentially useful ACS risk scores available however these have not undergone rigorous validation. This study suggests that these other scores may be potentially useful and should be further researched
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