240 research outputs found
A convergence on Boolean algebras generalizing the convergence on the Aleksandrov cube
We compare the forcing related properties of a complete Boolean algebra B
with the properties of the convergences (the algebraic convergence)
and on B generalizing the convergence on the Cantor and
Aleksandrov cube respectively. In particular we show that is a
topological convergence iff forcing by B does not produce new reals and that
is weakly topological if B satisfies condition
(implied by the -cc). On the other hand, if is a
weakly topological convergence, then B is a -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 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
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
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
High-order Dy multipole motifs observed in DyB2C2 with resonant soft x-ray Bragg diffraction
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 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
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
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
Efficacy and safety of immune checkpoint inhibitor rechallenge in individuals with hepatocellular carcinoma
BACKGROUND & AIMS: We investigated the efficacy and safety of immune checkpoint inhibitor (ICI) rechallenge in patients with hepatocellular carcinoma (HCC) who received ICI-based therapies in a previous systemic line. METHODS: In this international, retrospective multicenter study, patients with HCC who received at least two lines of ICI-based therapies (ICI-1, ICI-2) at 14 institutions were eligible. The main outcomes included best overall response and treatment-related adverse events. RESULTS: Of 994 ICI-treated patients screened, a total of 58 patients (male, n = 41; 71%) with a mean age of 65.0±9.0 years were included. Median systemic treatment lines of ICI-1 and ICI-2 were 1 (range, 1-4) and 3 (range, 2-9), respectively. ICI-based therapies used at ICI-1 and ICI-2 included ICI alone (ICI-1, n = 26, 45%; ICI-2, n = 4, 7%), dual ICI regimens (n = 1, 2%; n = 12, 21%), or ICI combined with targeted therapies/anti-VEGF (n = 31, 53%; n = 42, 72%). Most patients discontinued ICI-1 due to progression (n = 52, 90%). Objective response rate was 22% at ICI-1 and 26% at ICI-2. Responses at ICI-2 were also seen in patients who had progressive disease as best overall response at ICI-1 (n = 11/21; 52%). Median time-to-progression at ICI-1 and ICI-2 was 5.4 (95% CI 3.0-7.7) months and 5.2 (95% CI 3.3-7.0) months, respectively. Treatment-related adverse events of grade 3-4 at ICI-1 and ICI-2 were observed in 9 (16%) and 10 (17%) patients, respectively. CONCLUSIONS: ICI rechallenge was safe and resulted in a treatment benefit in a meaningful proportion of patients with HCC. These data provide a rationale for investigating ICI-based regimens in patients who progressed on first-line immunotherapy in prospective trials. IMPACT AND IMPLICATIONS: Therapeutic sequencing after first-line immune checkpoint inhibitor (ICI)-based therapy for advanced hepatocellular carcinoma (HCC) remains a challenge as no available second-line treatment options have been studied in immunotherapy-pretreated patients. Particularly, the role of ICI rechallenge in patients with HCC is unclear, as data from prospective trials are lacking. We investigated the efficacy and safety of ICI-based regimens in patients with HCC pretreated with immunotherapy in a retrospective, international, multicenter study. Our data provide the rationale for prospective trials investigating the role of ICI-based regimens in patients who have progressed on first-line immunotherapy
Mechanisms Associated with Activation of Intracellular Metabotropic Glutamate Receptor, mGluR5
Estas son algunas de las habilidades blandas demandadas en Colombia
Este producto forma parte de una serie de infografías de divulgación científica que buscan reseñar algunas de las investigaciones más importantes en las que ha tenido participación la Universidad EAFIT, publicadas en las revistas especializadas más prestigiosas del mund
Dynamical properties of critical and paramagnetic spin fluctuations in anisotropic Heisenberg magnets
SPIN-WAVE LIFETIME IN ANTIFERROMAGNETS
On déduit le temps de vie d'un magnon pour un antiferromagnétique décrit par un Hamiltonien de Dyson-Maleev. A cette fin on commence par les équations de mouvement des fonctions de Green thermiques, exprimées par les opérateurs des ondes de spin. Un simple procédé de découplement menant à la renormalisation de Hartree-Fock dans l'équation de premier ordre est étendu aux équations de second ordre, et donne la valeur du temps de vie d'un magnon. Une analyse à basses températures (kBT ≪ ωκ ≪ 2 rJS) fournit une largeur d'état proportionnelle à kT4.The magnon lifetime for an antiferromagnet described by a Dyson-Maleev Hamiltonian is derived in the spin-wave formalism from the equations of motion of thermal Green functions. A simple decoupling procedure leading to the Hartree-Fock renormalization in first order is extended to second-order equations and yields an expression for the magnon lifetime. A low temperature expansion for (kBT ≪ ωκ ≪2 rJS) produces an energy-width proportional to kT4
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