68 research outputs found

    Exact many-body scars and their stability in constrained quantum chains

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    Quantum scars are non-thermal eigenstates characterized by low entanglement entropy, initially detected in systems subject to nearest-neighbor Rydberg blockade, the so called PXP model. While most of these special eigenstates elude an analytical description and seem to hybridize with nearby thermal eigenstates for large systems, some of them can be written as matrix product states (MPS) with size-independent bond dimension. We study the response of these exact quantum scars to perturbations by analysing the scaling of the fidelity susceptibility with system size. We find that some of them are anomalously stable at first order in perturbation theory, in sharp contrast to the eigenstate thermalization hypothesis. However, this stability seems to breakdown when all orders are taken into account. We further investigate models with larger blockade radius and find a novel set of exact quantum scars, that we write down analytically and compare with the PXP exact eigenstates. We show that they exhibit the same robustness against perturbations at first order.Comment: 15 pages, 8 figure

    Large-Gauge Needle Biopsy in Diagnosing Malignant Breast Neoplasia

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    This paper is concerned with large-gauge needle biopsies of suspicious breast neoplasia performed within a three-year period (22nd June 1999 through 21st December 2001). Within that time 262 large-gauge needle biopsies as well as cytological punctions were performed with the aim of diagnosing benign and malignant neoplasia. In the same three-year period 29 malignant breast tumors were diagnosed. In one of the patients a clinically and PHD verified alteration was found which pointed to Mb. Padget, while in another patient an atypical ductal hyperplasia was confirmed by a pathohistological test

    The Recovery Phase after the 2009.0-event of η Carinae

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    The 5.5 years periodicity of eta Carinae is manifested in the "events" observed in different wavelength ranges. The last of these "events" occurred as expected in 2009.0. Our ground-based photometric campaign registered this "event" which showed an "eclipse-like" feature. After that, we continued the observations in order to get information about the post-event behaviour. Our monitoring program consists of daily CCD photometry, obtained using the 0.8 m "Virpi S. Niemela" telescope at La Plata Observatory, and a BVRI and H_alpha filter set. The light curves and photometric data collected during the second half of our 2009 observing season are presented in this paper.Facultad de Ciencias Astronómicas y GeofísicasInstituto de Astrofísica de La Plat

    Determinación de marcadores de origen botánico para mieles de citrus (citrus spp) de la región fronteriza: Concordia (República Argentina) – Salto (República Oriental del Uruguay)

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    Argentina y Uruguay son productores de mieles de alta calidad que destinan en más de un 95% a exportación, especialmente a países de la CEE. Mercados exigentes que valorizan mieles diferenciadas por origen botánico y geográfico. La región fronteriza Concordia-Salto se caracteriza por ser una zona de producción citrícola, que cuenta con extensas plantaciones dedicadas a la producción de naranjas y mandarinas, lo que constituye una fuente de néctar para las colmenas instaladas en el área por apicultores de ambos países. La miel de cítricos es muy apreciada comercialmente con un valor agregado importante cuando es posible diferenciarla. Una de las dificultades que se presentan, es que debido a características propias la especie,  el número de gránulos de polen en la miel suele ser escaso, dificultando determinar origen botánico solo con este parámetro. El estudio complementario de las características físico-químicas y composición del aroma, resulta un aporte importante para diferenciar y valorizar estas mieles. El objetivo general de este proyecto es disponer en la región fronteriza Concordia-Salto de una miel tipificada de Citrus con el fin de aumentar su valor agregado y mejorar su posicionamiento en los mercados internacionales,  a partir de hallar componentes aromáticos marcadores de origen botánico

    How future surgery will benefit from SARS-COV-2-related measures: a SPIGC survey conveying the perspective of Italian surgeons

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    COVID-19 negatively affected surgical activity, but the potential benefits resulting from adopted measures remain unclear. The aim of this study was to evaluate the change in surgical activity and potential benefit from COVID-19 measures in perspective of Italian surgeons on behalf of SPIGC. A nationwide online survey on surgical practice before, during, and after COVID-19 pandemic was conducted in March-April 2022 (NCT:05323851). Effects of COVID-19 hospital-related measures on surgical patients' management and personal professional development across surgical specialties were explored. Data on demographics, pre-operative/peri-operative/post-operative management, and professional development were collected. Outcomes were matched with the corresponding volume. Four hundred and seventy-three respondents were included in final analysis across 14 surgical specialties. Since SARS-CoV-2 pandemic, application of telematic consultations (4.1% vs. 21.6%; p < 0.0001) and diagnostic evaluations (16.4% vs. 42.2%; p < 0.0001) increased. Elective surgical activities significantly reduced and surgeons opted more frequently for conservative management with a possible indication for elective (26.3% vs. 35.7%; p < 0.0001) or urgent (20.4% vs. 38.5%; p < 0.0001) surgery. All new COVID-related measures are perceived to be maintained in the future. Surgeons' personal education online increased from 12.6% (pre-COVID) to 86.6% (post-COVID; p < 0.0001). Online educational activities are considered a beneficial effect from COVID pandemic (56.4%). COVID-19 had a great impact on surgical specialties, with significant reduction of operation volume. However, some forced changes turned out to be benefits. Isolation measures pushed the use of telemedicine and telemetric devices for outpatient practice and favored communication for educational purposes and surgeon-patient/family communication. From the Italian surgeons' perspective, COVID-related measures will continue to influence future surgical clinical practice

    VIII Encuentro de Docentes e Investigadores en Historia del Diseño, la Arquitectura y la Ciudad

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    Acta de congresoLa conmemoración de los cien años de la Reforma Universitaria de 1918 se presentó como una ocasión propicia para debatir el rol de la historia, la teoría y la crítica en la formación y en la práctica profesional de diseñadores, arquitectos y urbanistas. En ese marco el VIII Encuentro de Docentes e Investigadores en Historia del Diseño, la Arquitectura y la Ciudad constituyó un espacio de intercambio y reflexión cuya realización ha sido posible gracias a la colaboración entre Facultades de Arquitectura, Urbanismo y Diseño de la Universidad Nacional y la Facultad de Arquitectura de la Universidad Católica de Córdoba, contando además con la activa participación de mayoría de las Facultades, Centros e Institutos de Historia de la Arquitectura del país y la región. Orientado en su convocatoria tanto a docentes como a estudiantes de Arquitectura y Diseño Industrial de todos los niveles de la FAUD-UNC promovió el debate de ideas a partir de experiencias concretas en instancias tales como mesas temáticas de carácter interdisciplinario, que adoptaron la modalidad de presentación de ponencias, entre otras actividades. En el ámbito de VIII Encuentro, desarrollado en la sede Ciudad Universitaria de Córdoba, se desplegaron numerosas posiciones sobre la enseñanza, la investigación y la formación en historia, teoría y crítica del diseño, la arquitectura y la ciudad; sumándose el aporte realizado a través de sus respectivas conferencias de Ana Clarisa Agüero, Bibiana Cicutti, Fernando Aliata y Alberto Petrina. El conjunto de ponencias que se publican en este Repositorio de la UNC son el resultado de dos intensas jornadas de exposiciones, cuyos contenidos han posibilitado actualizar viejos dilemas y promover nuevos debates. El evento recibió el apoyo de las autoridades de la FAUD-UNC, en especial de la Secretaría de Investigación y de la Biblioteca de nuestra casa, como así también de la Facultad de Arquitectura de la UCC; va para todos ellos un especial agradecimiento

    Measurement of the very rare K+π+ννˉK^+ \to \pi^+ \nu \bar\nu decay

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    The decay K+→π+νν¯ , with a very precisely predicted branching ratio of less than 10−10 , is among the best processes to reveal indirect effects of new physics. The NA62 experiment at CERN SPS is designed to study the K+→π+νν¯ decay and to measure its branching ratio using a decay-in-flight technique. NA62 took data in 2016, 2017 and 2018, reaching the sensitivity of the Standard Model for the K+→π+νν¯ decay by the analysis of the 2016 and 2017 data, and providing the most precise measurement of the branching ratio to date by the analysis of the 2018 data. This measurement is also used to set limits on BR(K+→π+X ), where X is a scalar or pseudo-scalar particle. The final result of the BR(K+→π+νν¯ ) measurement and its interpretation in terms of the K+→π+X decay from the analysis of the full 2016-2018 data set is presented, and future plans and prospects are reviewed

    Omecamtiv mecarbil in chronic heart failure with reduced ejection fraction, GALACTIC‐HF: baseline characteristics and comparison with contemporary clinical trials

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    Aims: The safety and efficacy of the novel selective cardiac myosin activator, omecamtiv mecarbil, in patients with heart failure with reduced ejection fraction (HFrEF) is tested in the Global Approach to Lowering Adverse Cardiac outcomes Through Improving Contractility in Heart Failure (GALACTIC‐HF) trial. Here we describe the baseline characteristics of participants in GALACTIC‐HF and how these compare with other contemporary trials. Methods and Results: Adults with established HFrEF, New York Heart Association functional class (NYHA) ≥ II, EF ≤35%, elevated natriuretic peptides and either current hospitalization for HF or history of hospitalization/ emergency department visit for HF within a year were randomized to either placebo or omecamtiv mecarbil (pharmacokinetic‐guided dosing: 25, 37.5 or 50 mg bid). 8256 patients [male (79%), non‐white (22%), mean age 65 years] were enrolled with a mean EF 27%, ischemic etiology in 54%, NYHA II 53% and III/IV 47%, and median NT‐proBNP 1971 pg/mL. HF therapies at baseline were among the most effectively employed in contemporary HF trials. GALACTIC‐HF randomized patients representative of recent HF registries and trials with substantial numbers of patients also having characteristics understudied in previous trials including more from North America (n = 1386), enrolled as inpatients (n = 2084), systolic blood pressure < 100 mmHg (n = 1127), estimated glomerular filtration rate < 30 mL/min/1.73 m2 (n = 528), and treated with sacubitril‐valsartan at baseline (n = 1594). Conclusions: GALACTIC‐HF enrolled a well‐treated, high‐risk population from both inpatient and outpatient settings, which will provide a definitive evaluation of the efficacy and safety of this novel therapy, as well as informing its potential future implementation

    Estimation of potential benefits of the implementation of the fundamental review of the trading book and leverage ratio

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    The Fundamental Review of the Trading Book (FRTB) introduces changes in capital requirements as a consequence of changes in the calculation of risk weighted assets (RWAs), as agreed in the Basel Committee on Banking Supervision. This report performs an ex-ante assessment of the potential benefits of this new legislative proposal and is included as an annex to the Impact Assessment of the Capital Requirement Regulation II (CRR II) which was published on 23 November 2016. The analysis is conducted by estimating the required variation in banks’ capital following the implementation of the legislative changes by using econometric and statistical techniques. The estimated capital requirements are then used to feed a simulation model of losses originating from the banking sector in the event of a banking crisis. Results of the crisis simulation before and after the introduction of the legislative changes are compared to arrive at an estimation of the impacts. Benefits are measured as reduction in banks’ losses that need to be absorbed by different stakeholders, starting from shareholders and including the whole loss absorption cascade and financial safety net (i.e. bail-in and resolution funds)
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