255 research outputs found

    A convergence on Boolean algebras generalizing the convergence on the Aleksandrov cube

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    We compare the forcing related properties of a complete Boolean algebra B with the properties of the convergences λs\lambda_s (the algebraic convergence) and λls\lambda_{ls} on B generalizing the convergence on the Cantor and Aleksandrov cube respectively. In particular we show that λls\lambda_{ls} is a topological convergence iff forcing by B does not produce new reals and that λls\lambda_{ls} is weakly topological if B satisfies condition ()(\hbar) (implied by the t{\mathfrak t}-cc). On the other hand, if λls\lambda_{ls} is a weakly topological convergence, then B is a 2h2^{\mathfrak h}-cc algebra or in some generic extension the distributivity number of the ground model is greater than or equal to the tower number of the extension. So, the statement "The convergence λls\lambda_{ls} on the collapsing algebra B=\ro ((\omega_2)^{<\omega}) is weakly topological" is independent of ZFC

    Measurable Consequences of the Local Breakdown of the Concept of Temperature

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    Local temperature defined by a local canonical state of the respective subsystem, does not always exist in quantum many body systems. Here, we give some examples of how this breakdown of the temperature concept on small length scales might be observed in experiments: Measurements of magnetic properties of an anti-ferromagnetic spin-1 chain. We show that those magnetic properties are in fact strictly local. As a consequence their measurement reveals whether the local (reduced) state can be thermal. If it is, a temperature may be associated to the measurement results, while this would lead to inconsistencies otherwise.Comment: some comments added, results remain unchange

    Minimal length scales for the existence of local temperature

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    We review a recent approach to determine the minimal spatial length scales on which local temperature exists. After mentioning an experiment where such considerations are of relevance, we first discuss the precise definition of the existence of local temperature and its physical relevance. The approach to calculate the length scales in question considers homogenous chains of particles with nearest neighbor interactions. The entire chain is assumed to be in a thermal equilibrium state and it is analyzed when such an equilibrium state at the same time exists for a local part of it. The result yields estimates for real materials, the liability of which is discussed in the sequel. We finally consider a possibility to detect the existence or non-existence of a local thermal state in experiment.Comment: review, 13 pages, 11 figure

    Impactos en las propiedades del suelo de los bosques de pinabete en terrenos agrícolas abandonados

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    Forest floor is considered a major feature distinguishing forest from agricultural soils. Forest floor develops as forest stands grow and is composed of more or less altered plant-tissue biomass accumulated on the soil surface. Our study’s aim was to find whether properties of both the organic layers and mineral soil differ according to the land-use history of the sites compared. Each site included an afforested area of immature 50-year-old spruce forest (AFF) on formerly agricultural land plus an adjacent area of old-growth 100-year-old spruce stand (FOR). The localities are situated at altitudes ranging between 600 and 850 metres above sea level. From the results of our study it can be concluded that both forest floor and mineral soil had higher pH and Ca concentration at formerly agricultural sites. C/N ratio is significantly lower in afforested soil. First-generation humus was significantly higher in phosphorus.El piso forestal es considerado una de las principales características distintivas de los suelos forestales frente a los agrícolas. El piso forestal se desarrolla según crecen las masas forestales y se compone de tejidos de vegetales de la biomasa más o menos alterados acumulados en la superficie del suelo. El objetivo de nuestro estudio fue determinar si las propiedades de las capas orgánicas y minerales del suelo difieren de acuerdo a la historia del uso del suelo de los sitios. Cada sitio incluye un área reforestada de bosque de pinabete inmaduro de 50 años de edad (AFF) en antiguo terreno agrícola, más un área adyacente madura de pinabete de 100 años de edad. Las localidades se encuentran en altitudes que oscilan entre 600 y 850 metros sobre el nivel del mar. De los resultados de nuestro estudio se puede concluir que tanto el suelo del bosque como el suelo mineral tenían un pH más alto y mayor concentración de Ca en los sitios agrícolas abandonados. La relación C/N es significativamente menor en los suelos reforestados. La primera generación de humus presentó un significativamente mayor contenido en fósforo

    High-order Dy multipole motifs observed in DyB2C2 with resonant soft x-ray Bragg diffraction

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    Resonant soft x-ray Bragg diffraction at the Dy M4,5 edges has been exploited to study Dy multipole motifs in DyB2C2. Our results are explained introducing the intra-atomic quadrupolar interaction between the core 3d and valence 4f shell. This allows us to determine for the first time higher order multipole moments of dysprosium 4f4f electrons and to draw their precise charge density. The Dy hexadecapole and hexacontatetrapole moment have been estimated at -20% and +30% of the quadrupolar moment, respectively. No evidence for the lock-in of the orbitals at T_N has been observed, in contrast to earlier suggestions. The multipolar interaction and the structural transition cooperate along c but they compete in the basal plane explaining the canted structure along [110].Comment: 4 pages, 3 figure

    Vrednovanje superčistih čelika prema kemijskom sastavu

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    Realization of products in power engineering represents the verification and optimization of steel making technology of 2,8NiCrMoV and 3,5NiCrMoV types intended for forgings of the gas turbine shaft and compressor disk. The minimum content of tramp and trace elements is requested, especially phosphorus, sulphur, copper, antimony, arsenic and tin. Silicon, manganese and aluminium are considered as undesirable elements.Realizacija proizvoda u energetskom inženjerstvu predstavlja optimalizaciju tehnologije proizvodnje čelika tipa 2,8NiCrMoV i 3,5NiCrMoV namijenjenim kovanju osovine plinske turbine i diska kompresora. Zahtijeva se minimalni sadržaj pratećih elemenata i oligoelemenata, naročito fosfora, sumpora, bakra, antimona, arsena i kositra. Silicij, magnezij i aluminij se smatraju nepoželjnim elementima

    Cardiac Glycosides Ouabain and Digoxin Interfere with the Regulation of Glutamate Transporter GLAST in Astrocytes Cultured from Neonatal Rat Brain

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    Glutamate transport (GluT) in brain is mediated chiefly by two transporters GLT and GLAST, both driven by ionic gradients generated by (Na+, K+)-dependent ATPase (Na+/K+-ATPase). GLAST is located in astrocytes and its function is regulated by translocations from cytoplasm to plasma membrane in the presence of GluT substrates. The phenomenon is blocked by a naturally occurring toxin rottlerin. We have recently suggested that rottlerin acts by inhibiting Na+/K+-ATPase. We now report that Na+/K+-ATPase inhibitors digoxin and ouabain also blocked the redistribution of GLAST in cultured astrocytes, however, neither of the compounds caused detectable inhibition of ATPase activity in cell-free astrocyte homogenates (rottlerin inhibited app. 80% of Pi production from ATP in the astrocyte homogenates, IC50 = 25 μM). Therefore, while we may not have established a direct link between GLAST regulation and Na+/K+-ATPase activity we have shown that both ouabain and digoxin can interfere with GluT transport and therefore should be considered potentially neurotoxic

    A novel splice variant of the Excitatory Amino Acid Transporter 5: cloning, immunolocalization and functional characterization of hEAAT5v in human retina

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    Excitatory Amino Acid Transporter 5 (EAAT5) is abundantly expressed by retinal photoreceptors and bipolar cells, where it acts as a slow glutamate transporter and a glutamate-gated chloride channel. The chloride conductance is large enough for EAAT5 to serve as an “inhibitory” glutamate receptor. Our recent work in rodents has shown that EAAT5 is differentially spliced and exists in many variant forms. The chief aim of the present study was to examine whether EAAT5 is also alternately spliced in human retina and, if so, what significance this might have for retinal function in health and disease. Retinal tissues from human donor eyes were used in RT-PCR to amplify the entire coding region of EAAT5. Amplicons of differing sizes were sub-cloned and analysis of sequenced data revealed the identification of wild-type human EAAT5 (hEAAT5) and an abundant alternately spliced form, referred to as hEAAT5v, where the open reading frame is expanded by insertion of an additional exon. hEAAT5v encodes a protein of 619 amino acids and when expressed in COS7 cells, the protein functioned as a glutamate transporter. We raised antibodies that selectively recognized the hEAAT5v protein and have performed immunocytochemistry to demonstrate expression in photoreceptors in human retina. We noted that in retinas afflicted by dry aged-related macular degeneration (AMD), there was a loss of hEAAT5v from the lesioned area and from photoreceptors adjacent to the lesion. We conclude that hEAAT5v protein expression may be perturbed in peri-lesional areas of AMD-afflicted retinas that do not otherwise exhibit evidence of damage. The loss of hEAAT5v could, therefore, represent an early pathological change in the development of AMD and might be involved in its aetiology

    Safety of direct oral anticoagulants in patients with advanced liver disease

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    BACKGROUND & AIMS: While direct oral anticoagulants (DOACs) are increasingly used in patients with liver disease, safety data especially in advanced chronic liver disease (ACLD) are limited. METHODS: Liver disease patients receiving DOAC treatment (ACLD: n = 104; vascular liver disease: n = 29) or vitamin K antagonists (VKA)/low‐molecular‐weight heparin (LMWH; ACLD: n = 45; vascular: n = 13) between January 2010 and September 2020 were retrospectively included. Invasive procedures and bleeding events were recorded. Calibrated anti‐Xa peak levels and thrombomodulin‐modified thrombin generation assays (TM‐TGAs) were measured in a subgroup of 35/28 DOAC patients. RESULTS: Among patients receiving DOAC, 55 (41.3%) had advanced liver dysfunction (Child‐Pugh‐stage [CPS] B/C) and 66 (49.6%) had experienced decompensation. Overall, 205 procedures were performed in 60 patients and procedure‐related bleedings occurred in 7 (11.7%) patients. Additionally, 38 (28.6%) patients experienced spontaneous (15 minor, 23 major) bleedings during a median follow‐up of 10.5 (IQR: 4.0‐27.8) months. Spontaneous bleedings in ACLD patients were more common in CPS‐B/C (at 12 months: 36.9% vs CPS‐A: 15.9%, subdistribution hazard ratio [SHR]: 3.23 [95% CI: 1.59‐6.58], P < .001), as were major bleedings (at 12 months: 22.0% vs 5.0%, SHR: 5.82 [95% CI: 2.00‐16.90], P < .001). Importantly, CPS (adjusted SHR: 4.12 [91% CI: 1.82‐9.37], P < .001), but not the presence of hepatocellular carcinoma or varices, was independently associated with major bleeding during DOAC treatment. Additionally, ACLD patients experiencing bleeding had worse overall survival (at 12 months: 88.9% vs 95.0% without bleeding; P < .001). Edoxaban anti‐Xa peak levels were higher in patients with CPS‐B/C (345 [95% CI: 169‐395] vs CPS‐A: 137 [95% CI: 96‐248] ng/mL, P = .048) and were associated with lower TM‐TGA. Importantly, spontaneous bleeding rates were comparable to VKA/LMWH patients. CONCLUSIONS: Anticoagulants including DOACs should be used with caution in patients with advanced liver disease due to a significant rate of spontaneous bleeding events

    La relación entre Curso de articulación o propedéutico y rendimiento de los alumnos en la Cátedra de Introducción a la Teoría Contable de la Facultad de Ciencias Económicas de la Universidad Nacional de Entre Ríos

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    El Proyecto de Investigación denominado “La relación entre Curso de articulación o propedéutico y rendimiento de los alumnos en la Cátedra de Introducción a la Teoría Contable de la Facultad de Ciencias Económicas de la Universidad Nacional de Entre Ríos”, basado en las Cohortes 2010-2011, 2011-2012 y 2012-2013, tiene como objetivo realizar el seguimiento de los resultados en exámenes parciales y finales realizados por los alumnos de la Cátedra de Introducción a la Teoría Contable, luego de haber cursado y aprobado el Curso de Articulación o Propedéutico, respectivamente en forma obligatoria para poder acceder al cursado de la cátedra mencionada. La inquietud de relacionar el curso de articulación o propedéutico con el rendimiento en la cátedra, se origina en tratar de establecer si existen diferencias en los resultados de las evaluaciones, según se haya participado o no de los cursos mencionados, considerando una instancia propicia para realizar el estudio el inicio del ciclo lectivo 2011, en que se establece la obligatoriedad de esas instancias.El proyecto de articulación está destinado a los alumnos aspirantes a ingresar a la Facultad de Ciencias Económicas, con el propósito de desarrollar contenidos teóricos y prácticos acordes con los criterios adoptado por la cátedra de “Introducción a la Teoría Contable”. Con él se pretende lograr dos objetivos: por un lado, nivelar el conocimiento de los alumnos formados en la materia contable y, por otro lado, servir de curso introductorio para aquellos alumnos no formados en dicha materia.El presente informe expone el análisis descriptivo de los datos de los ingresantes 2010, 2011, 2012 y 2013 como así también estudia posibles relaciones entre la obligatoriedad implementada en el curso de articulación o propedéutico a partir del año 2011 y el rendimiento observado en la asignatura Introducción a la Teoría Contabl
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