518 research outputs found
Existence of solutions to a higher dimensional mean-field equation on manifolds
For we prove an existence result for the equation on a closed Riemannian
manifold of dimension for certain values of .Comment: 15 Page
A Codazzi-like equation and the singular set for smooth surfaces in the Heisenberg group
In this paper, we study the structure of the singular set for a
smooth surface in the -dimensional Heisenberg group . We
discover a Codazzi-like equation for the -area element along the
characteristic curves on the surface. Information obtained from this ordinary
differential equation helps us to analyze the local configuration of the
singular set and the characteristic curves. In particular, we can estimate the
size and obtain the regularity of the singular set. We understand the global
structure of the singular set through a Hopf-type index theorem. We also
justify that Codazzi-like equation by proving a fundamental theorem for local
surfaces in .Comment: 64 pages, 17 figure
InterjecciĂłn y extrapredicaciĂłn
Aquest article versa sobre la interjecciĂł i intenta analitzar el seu comportament de cara a realitzar una
aproximaciĂł entre aquesta unitat i la extraprediciĂłn. Des dâun enfocament essencialment funcional,
explora la interjecciĂł aixĂ com lâextrapredicaciĂł del seu funcionament. Acaba observant que aquesta
unitat neurolingĂŒĂstica Ă©s eminentment extrapredicativa.Este artĂculo versa sobre la interjecciĂłn e intenta analizar su comportamiento con vistas a realizar una
aproximaciĂłn entre esta unidad y la extrapredicaciĂłn. Desde un enfoque esencialmente funcional,
explora la interjecciĂłn asĂ como la extraprediciĂłn de su funcionamiento. Termina observando que
esta unidad neurolingĂŒĂstica es eminentemente extrapredicativa.Cet article traite de lâinterjection et tente dâanalyser son comportement afin de faire une approximation
entre cette unitĂ© et lâextraprĂ©dication. Dâune approche essentiellement fonctionnelle, il explore
lâinterjection ainsi que lâextraprĂ©diction de son fonctionnement. Il conclut en observant que cette
unité neurolinguistique est éminemment extra-prédictive.This paper focuses on interjection and aims to explore how it behaves, in order to make an
approximation between this linguistic unit and the phenomenon called extrapredication. The
perspective used here is essencially functional and, from this theory, the paper analyse the interjection
and the extrapredication considering how it operates in the sentence. By the end, the constat is that
this neurolinguistic unit is essencially extrapredicative
Time representation in reinforcement learning models of the basal ganglia
Reinforcement learning (RL) models have been influential in understanding many aspects of basal ganglia function, from reward prediction to action selection. Time plays an important role in these models, but there is still no theoretical consensus about what kind of time representation is used by the basal ganglia. We review several theoretical accounts and their supporting evidence. We then discuss the relationship between RL models and the timing mechanisms that have been attributed to the basal ganglia. We hypothesize that a single computational system may underlie both RL and interval timingâthe perception of duration in the range of seconds to hours. This hypothesis, which extends earlier models by incorporating a time-sensitive action selection mechanism, may have important implications for understanding disorders like Parkinson's disease in which both decision making and timing are impaired
An improved geometric inequality via vanishing moments, with applications to singular Liouville equations
We consider a class of singular Liouville equations on compact surfaces
motivated by the study of Electroweak and Self-Dual Chern-Simons theories, the
Gaussian curvature prescription with conical singularities and Onsager's
description of turbulence. We analyse the problem of existence variationally,
and show how the angular distribution of the conformal volume near the
singularities may lead to improvements in the Moser-Trudinger inequality, and
in turn to lower bounds on the Euler-Lagrange functional. We then discuss
existence and non-existence results.Comment: some references adde
Simultaneous Learning of Fuzzy Sets
We extend a procedure based on support vector clustering and devoted to inferring the membership function of a fuzzy set to the case of a universe of discourse over which several fuzzy sets are defined. The extended approach learns simultaneously these sets without requiring as previous knowledge either their number or labels approximating membership values. This data-driven approach is completed via expert knowledge incorporation in the form of predefined shapes for the membership functions. The procedure is successfully tested on a benchmark
New improved Moser-Trudinger inequalities and singular Liouville equations on compact surfaces
We consider a singular Liouville equation on a compact surface, arising from
the study of Chern-Simons vortices in a self dual regime. Using new improved
versions of the Moser-Trudinger inequalities (whose main feature is to be
scaling invariant) and a variational scheme, we prove new existence results.Comment: to appear in GAF
Inhibition of HIV-1 Replication in Human Monocyte-Derived Macrophages by Parasite Trypanosoma cruzi
and HIV-1 to date.0.01). inhibits HIV-1 replication at several replication stages in macrophages, a major cell target for both pathogens
Sign-changing tower of bubbles for a sinh-Poisson equation with asymmetric exponents
Motivated by the statistical mechanics description of stationary
2D-turbulence, for a sinh-Poisson type equation with asymmetric nonlinearity,
we construct a concentrating solution sequence in the form of a tower of
singular Liouville bubbles, each of which has a different degeneracy exponent.
The asymmetry parameter corresponds to the ratio between the
intensity of the negatively rotating vortices and the intensity of the
positively rotating vortices. Our solutions correspond to a superposition of
highly concentrated vortex configurations of alternating orientation; they
extend in a nontrivial way some known results for . Thus, by
analyzing the case we emphasize specific properties of the
physically relevant parameter in the vortex concentration phenomena
Mechanisms of oxygenation responses to proning and recruitment in COVID-19 pneumonia
Purpose: This study aimed at investigating the mechanisms underlying the oxygenation response to proning and recruitment maneuvers in coronavirus disease 2019 (COVID-19) pneumonia. Methods: Twenty-five patients with COVID-19 pneumonia, at variable times since admission (from 1 to 3 weeks), underwent computed tomography (CT) lung scans, gas-exchange and lung-mechanics measurement in supine and prone positions at 5 cmH2O and during recruiting maneuver (supine, 35 cmH2O). Within the non-aerated tissue, we differentiated the atelectatic and consolidated tissue (recruitable and non-recruitable at 35 cmH2O of airway pressure). Positive/negative response to proning/recruitment was defined as increase/decrease of PaO2/FiO2. Apparent perfusion ratio was computed as venous admixture/non aerated tissue fraction. Results: The average values of venous admixture and PaO2/FiO2 ratio were similar in supine-5 and prone-5. However, the PaO2/FiO2 changes (increasing in 65% of the patients and decreasing in 35%, from supine to prone) correlated with the balance between resolution of dorsal atelectasis and formation of ventral atelectasis (p = 0.002). Dorsal consolidated tissue determined this balance, being inversely related with dorsal recruitment (p = 0.012). From supine-5 to supine-35, the apparent perfusion ratio increased from 1.38 ± 0.71 to 2.15 ± 1.15 (p = 0.004) while PaO2/FiO2 ratio increased in 52% and decreased in 48% of patients. Non-responders had consolidated tissue fraction of 0.27 ± 0.1 vs. 0.18 ± 0.1 in the responding cohort (p = 0.04). Consolidated tissue, PaCO2 and respiratory system elastance were higher in patients assessed late (all p < 0.05), suggesting, all together, âfibrotic-likeâ changes of the lung over time. Conclusion: The amount of consolidated tissue was higher in patients assessed during the third week and determined the oxygenation responses following pronation and recruitment maneuvers
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