312 research outputs found

    A measure of tripartite entanglement in bosonic and fermionic systems

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    We describe an efficient theoretical criterion suitable for the evaluation of the tripartite entanglement of any mixed three-boson or -fermion state, based on the notion of the entanglement of particles for bipartite systems of identical particles. Our approach allows one to quantify the accessible amount of quantum correlations in the systems without any violation of the local particle number superselection rule. A generalization of the tripartite negativity is here applied to some correlated systems including the continuous-time quantum walks of identical particles (both for bosons and fermions) and compared with other criteria recently proposed in the literature. Our results show the dependence of the entanglement dynamics upon the quantum statistics: the bosonic bunching results into a low amount of quantum correlations while Fermi-Dirac statistics allows for higher values of the entanglement.Comment: 19 pages, 3 figure

    Dynamics of quantum correlations in colored environments

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    We address the dynamics of entanglement and quantum discord for two non interacting qubits initially prepared in a maximally entangled state and then subjected to a classical colored noise, i.e. coupled with an external environment characterized by a noise spectrum of the form 1/fα1/f^{\alpha}. More specifically, we address systems where the Gaussian approximation fails, i.e. the sole knowledge of the spectrum is not enough to determine the dynamics of quantum correlations. We thus investigate the dynamics for two different configurations of the environment: in the first case the noise spectrum is due to the interaction of each qubit with a single bistable fluctuator with an undetermined switching rate, whereas in the second case we consider a collection of classical fluctuators with fixed switching rates. In both cases we found analytical expressions for the time dependence of entanglement and quantum discord, which may be also extended to a collection of flcutuators with random switching rates. The environmental noise is introduced by means of stochastic time-dependent terms in the Hamiltonian and this allows us to describe the effects of both separate and common environments. We show that the non-Gaussian character of the noise may lead to significant effects, e.g. environments with the same power spectrum, but different configurations, give raise to opposite behavior for the quantum correlations. In particular, depending on the characteristics of the environmental noise considered, both entanglement and discord display either a monotonic decay or the phenomena of sudden death and revivals. Our results show that the microscopic structure of environment, besides its noise spectrum, is relevant for the dynamics of quantum correlations, and may be a valid starting point for the engineering of non-Gaussian colored environments.Comment: 8 pages, 3 figure

    Hemodynamic on abdominal aortic aneurysm: Parametric study

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    El objetivo del presente estudio es determinar qué influencia tienen los parámetros geométricos con las tensiones hemodinámicas en aneurismas abdominales aórticos. Para ello los autores han creado varios modelos geométricos de aneurismas abdominales basándose en sus principales características geométricas (diámetro máximo, diámetro mínimo, longitud aneurisma y asimetría) y técnicas computacionales para calcular la presión y la tensión de corte en el saco aneurismático. Los resultados obtenidos constatan que la presión hemodinámica es la principal carga mecánica que actúa sobre la pared arterial y que la morfometría de los aneurismas podría ser utilizada como buen predictor del riesgo de rotura. Posteriormente, con el objetivo de determinar si los modelos geométricos se podrían usar como aproximación de modelos reales, se compararon varios modelos reales (patient-specific) con sus respectivos modelos geométricos obteniendo una buena aproximación.The aim of this study is to assess how the shape of the abdominal aortic aneurysms (AAA) affects the hemodynamic wall stresses. With this purpose, different AAAs are studied through simplified models based on geometrical parameters of the aneurism such as its maximum and minimum diameter, length and asymmetry. Then, a computational fluid dynamics analysis is performed on the simplified models in order to compute pressure and wall shear stresses on the aneurysm sac. The results obtained show that blood pressure is the main dynamic load acting on the artery wall, and that the morphology of the aneurysm could be a good indicator of risk of failure. Furthermore, the computational results are compared with patient-specific real models with the objective to assess the reliability of the proposed simplified approach.Peer Reviewe

    Estimation of interferences in the determination of fructosamine of feline and canine serum

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    The fructosamine serum concentration reflects the degree of glycemic control obtained during a\npreceding period. Usually, the presence of hemoglobin or bilirrubin in blood samples, could cause\ninterferences in the laboratory analytical assays.Thus, we investigated the possible interferences\non fructosamine determinations in serum from healthy cats and dogs. To testing and quantify\nthe interference, we construct interferograms adding increased concentrations of hemoglobin\nor bilirrubin to serum pools of cats or dogs. We tested serum hemoglobin concentrations from\n0.19 to 7.5 g/l in feline sera and 0.16 to 6.10 g/l in canine sera. The bilirrubin testing was\ndone from 6 to 600 mg/l in both species sera. The results had shown a hemoglobin positive\nand additive interference in feline sera (?1.60 g/l) and a negative interference in canine sera\n(?1.20 g/l). In addition both species had shown positive and additive bilirrubin interferences\n(?30 mg/l for feline sera and ?150 mg/l for canine sera).Fil: Colla, C. Universidad Nacional de Rosario. Facultad de Ciencias Veterinarias. Cátedra de Farmacología y Terapéutica; ArgentinaFil: Rodriguez, J. Universidad Nacional de Rosario. Facultad de Ciencias Veterinarias. Cátedra de Farmacología y Terapéutica; ArgentinaFil: Rodriguez, J. Universidad Nacional de Rosario. Centro Binacional (Argentina-Italia) de Investigaciones en Criobiología Clínica y Aplicada; ArgentinaFil: Rabe, G. Universidad Nacional de Rosario. Facultad de Ciencias Veterinarias. Cátedra de Farmacología y Terapéutica; ArgentinaFil: Patalano, C. Universidad Nacional de Rosario. Facultad de Ciencias Veterinarias. Cátedra de Farmacología y Terapéutica; ArgentinaFil: Perassi, M. Universidad Nacional de Rosario. Facultad de Ciencias Veterinarias. Cátedra de Farmacología y Terapéutica; ArgentinaFil: Bordone, F. Universidad Nacional de Rosario. Facultad de Ciencias Veterinarias. Cátedra de Farmacología y Terapéutica; ArgentinaFil: Cerrutti, J. Universidad Nacional de Rosario. Facultad de Ciencias Veterinarias. Cátedra de Farmacología y Terapéutica; ArgentinaLa concentración de fructosamina en suero es útil para monitorear el control de la glucemia en\nun período precedente.En muestras de sangre, la presencia de hemoglobina y bilirrubina pueden\ncausar interferencias en técnicas analíticas diagnósticas. Por ello, el objetivo de este trabajo fue\nevaluar la posible interferencia al medir fructosamina sérica de gatos y perros clínicamente sanos.\nSe construyeron interferogramas, agregando concentraciones crecientes del posible interferente\na pools de sueros de ambas especies. Se estudiaron concentraciones de hemoglobina desde 0.19\na 7.5 g/l en felinos, y de 0.16 a 6.10 g/l en caninos. Para bilirrubina, desde 6 a 600 mg/l, en\nambas especies. Los resultados mostraron interferencia positiva y aditiva de hemoglobina en\nfelinos (?1.60 g/l) e interferencia negativa en caninos (?1.20 g/l). En ambas especies se observaron\ninterferencias positivas y aditivas para bilirrubina en el rango de concentraciones estudiadas\n(?30 mg/l para felinos y ?150 mg/l para caninos)

    Intergenerational family caregiving in welfare policy context

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    Definition Intergenerational family caregiving refers to exchanges up and down family lines aimed at nurturing the needs of others. Caregiving is more than a task; it involves emotional and relationship work

    Blockade of EIF5A hypusination limits colorectal cancer growth by inhibiting MYC elongation

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    Eukaryotic Translation Initiation Factor 5A (EIF5A) is a translation factor regulated by hypusination, a unique posttranslational modification catalyzed by deoxyhypusine synthetase (DHPS) and deoxyhypusine hydroxylase (DOHH) starting from the polyamine spermidine. Emerging data are showing that hypusinated EIF5A regulates key cellular processes such as autophagy, senescence, polyamine homeostasis, energy metabolism, and plays a role in cancer. However, the effects of EIF5A inhibition in preclinical cancer models, the mechanism of action, and specific translational targets are still poorly understood. We show here that hypusinated EIF5A promotes growth of colorectal cancer (CRC) cells by directly regulating MYC biosynthesis at specific pausing motifs. Inhibition of EIF5A hypusination with the DHPS inhibitor GC7 or through lentiviral-mediated knockdown of DHPS or EIF5A reduces the growth of various CRC cells. Multiplex gene expression analysis reveals that inhibition of hypusination impairs the expression of transcripts regulated by MYC, suggesting the involvement of this oncogene in the observed effect. Indeed, we demonstrate that EIF5A regulates MYC elongation without affecting its mRNA content or protein stability, by alleviating ribosome stalling at five distinct pausing motifs in MYC CDS. Of note, we show that blockade of the hypusination axis elicits a remarkable growth inhibitory effect in preclinical models of CRC and significantly reduces the size of polyps in APCMin/+ mice, a model of human familial adenomatous polyposis (FAP). Together, these data illustrate an unprecedented mechanism, whereby the tumor-promoting properties of hypusinated EIF5A are linked to its ability to regulate MYC elongation and provide a rationale for the use of DHPS/EIF5A inhibitors in CRC therapy

    The risk stratification of adverse neonatal outcomes in women with gestational diabetes (STRONG) study

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    Aims: To assess the risk of adverse neonatal outcomes in women with gestational diabetes (GDM) by identifying subgroups of women at higher risk to recognize the characteristics most associated with an excess of risk. Methods: Observational, retrospective, multicenter study involving consecutive women with GDM. To identify distinct and homogeneous subgroups of women at a higher risk, the RECursive Partitioning and AMalgamation (RECPAM) method was used. Overall, 2736 pregnancies complicated by GDM were analyzed. The main outcome measure was the occurrence of adverse neonatal outcomes in pregnancies complicated by GDM. Results: Among study participants (median age 36.8 years, pre-gestational BMI 24.8 kg/m2), six miscarriages, one neonatal death, but no maternal death was recorded. The occurrence of the cumulative adverse outcome (OR 2.48, 95% CI 1.59–3.87), large for gestational age (OR 3.99, 95% CI 2.40–6.63), fetal malformation (OR 2.66, 95% CI 1.00–7.18), and respiratory distress (OR 4.33, 95% CI 1.33–14.12) was associated with previous macrosomia. Large for gestational age was also associated with obesity (OR 1.46, 95% CI 1.00–2.15). Small for gestational age was associated with first trimester glucose levels (OR 1.96, 95% CI 1.04–3.69). Neonatal hypoglycemia was associated with overweight (OR 1.52, 95% CI 1.02–2.27) and obesity (OR 1.62, 95% CI 1.04–2.51). The RECPAM analysis identified high-risk subgroups mainly characterized by high pre-pregnancy BMI (OR 1.68, 95% CI 1.21–2.33 for obese; OR 1.38 95% CI 1.03–1.87 for overweight). Conclusions: A deep investigation on the factors associated with adverse neonatal outcomes requires a risk stratification. In particular, great attention must be paid to the prevention and treatment of obesity

    Overview on the phenomenon of two-qubit entanglement revivals in classical environments

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    The occurrence of revivals of quantum entanglement between separated open quantum systems has been shown not only for dissipative non-Markovian quantum environments but also for classical environments in absence of back-action. While the phenomenon is well understood in the first case, the possibility to retrieve entanglement when the composite quantum system is subject to local classical noise has generated a debate regarding its interpretation. This dynamical property of open quantum systems assumes an important role in quantum information theory from both fundamental and practical perspectives. Hybrid quantum-classical systems are in fact promising candidates to investigate the interplay among quantum and classical features and to look for possible control strategies of a quantum system by means of a classical device. Here we present an overview on this topic, reporting the most recent theoretical and experimental results about the revivals of entanglement between two qubits locally interacting with classical environments. We also review and discuss the interpretations provided so far to explain this phenomenon, suggesting that they can be cast under a unified viewpoint.Comment: 16 pages, 9 figures. Chapter written for the upcoming book "Lectures on general quantum correlations and their applications
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