Symmetric Hyperbolic System in the Self-dual Teleparallel Gravity

In order to discuss the well-posed initial value formulation of the teleparallel gravity and apply it to numerical relativity a symmetric hyperbolic system in the self-dual teleparallel gravity which is equivalent to the Ashtekar formulation is posed. This system is different from the ones in other works by that the reality condition of the spatial metric is included in the symmetric hyperbolicity and then is no longer an independent condition. In addition the constraint equations of this system are rather simpler than the ones in other works.Comment: 8 pages, no figure

Aeolian transport layer

We investigate the airborne transport of particles on a granular surface by the saltation mechanism through numerical simulation of particle motion coupled with turbulent flow. We determine the saturated flux $q_{s}$ and show that its behavior is consistent with a classical empirical relation obtained from wind tunnel measurements. Our results also allow to propose a new relation valid for small fluxes, namely, $q_{s}=a(u_{*}-u_{t})^{\alpha}$, where $u_{*}$ and $u_{t}$ are the shear and threshold velocities of the wind, respectively, and the scaling exponent is $\alpha \approx 2$. We obtain an expression for the velocity profile of the wind distorted by the particle motion and present a dynamical scaling relation. We also find a novel expression for the dependence of the height of the saltation layer as function of the wind velocity.Comment: 4 pages, 4 figure

Phytotherapics in tissue healing and its interface with professionals of health in Brazil / Fitoterápicos na cicatrização de tecidos e sua interface com profissionais de saúde no Brasil

The World Health Organization and many other national health conferences have stimulated the use of phytotherapeutics and medicinal plants in primary health care in Brazil. Phytotherapeutics and the use of medicinal plants are part of the folk medicine practice, which complements the treatment that is usually employed by lower income population. There is a growing interest in researches about improving the knowledge of plants’ medicinal properties used in tissue healing. This process occurs as a biological response after injury, where uncountable signaling pathways are stimulated to restore the homeostasis of the affected structure. It is observed that Brazil has been developing important researches to improve the knowledge of plants’ medicinal properties favoring a greater prescription by the health professionals and also a better use by the population. Phototherapeutics act in tissue repair in different ways, and the present review describes the use of these in healing in experimental researches and its interface with professionals of health. In this research, we checked scientific articles (Medline, Scielo, Lilacs, Coordination of Superior Level Staff Improvement (CAPES), PubMed and Google Scholar) published between years 2000 and 2018. Companies, researchers, professionals of health and the general population have shown an interest in phytotherapeutics compounds as alternatives for the treatment of various conditions and the healing of injuries. This is due to the lower side effects, easy access and low cost of herbal medicines compared to allopathic medicines and the rich biodiversity from the Brazilian flora. However, it is necessary for the health professionals training and motivation, aiming at a correct and safe prescription and the use of herbal medicines in tissue healing, as well as the insertion of this practice into their professional qualification.

Localized spin ordering in Kondo lattice models

Using a non-Abelian density matrix renormalization group method we determine the phase diagram of the Kondo lattice model in one dimension, by directly measuring the magnetization of the ground-state. This allowed us to discover a second ferromagnetic phase missed in previous approaches. The phase transitions are found to be continuous. The spin-spin correlation function is studied in detail, and we determine in which regions the large and small Fermi surfaces dominate. The importance of double-exchange ordering and its competition with Kondo singlet formation is emphasized in understanding the complexity of the model.Comment: Revtex, 4 pages, 4 eps figures embedde

Aterosclerose e lesões do endotélio vascular e as perspectivas clínicas na utilização das células progenitoras endoteliais no seu reparo / Atherosclerosis and vascular endothelium lesions and the clinical perspectives in the use of endothelial progenitor cells in their repair

O endotélio vascular desempenha um papel central na preservação funcional e estrutural da parede vascular. Além da permeabilidade vascular, a célula endotelial influencia o tônus vascular, hemóstase, proliferação celular, respostas imunológicas e inflamatórias e a expressão fenotípica das células musculares lisas da túnica média. Íntima e fisiopatologicamente relacionado com a hipertensão arterial, dislipoproteinemias e aterosclerose, o órgão endotelial é hoje enfrentado como origem e alvo de diferentes tratamentos que visam melhorar o prognóstico da doença aterosclerótica. Este trabalho objetivou estabelecer a aterosclerose, patologia que causa lesões no endotélio vascular e as perspectivas clínicas na utilização das células progenitoras endoteliais (CPEs) no seu reparo. Na pesquisa, foram verificados artigos científicos nas bases de dados Medline, Scielo, Lilacs, CAPES, PubMed, dentre outras publicados entre os anos de 1996 e 2020. Estratégias terapêuticas são promissoras com o uso das CPEs na diferenciação e regeneração do endotélio, sendo uma fonte promissora na revascularização de tecidos isquêmicos e muito embora a prevenção e o tratamento já estabelecidos permaneça crucial para a abordagem das cardiopatias, as perspectivas da terapia com CPEs são instigantes. 

Evolução na utilização e nos gastos de uma operadora de saúde

Brazil’s aging population and the rising number of people reliant upon the country’s supplementary healthcare system have elicited the concern of public and private managers regarding the increase in healthcare costs. In this paper, the costs per gender, per type of medical expenses and per age group of a major Brazilian self-managed healthcare provider between 2007 and 2013 were analyzed. This healthcare provider is of interest because, besides portraying a single condition of revenue growth restricted to the existing contributors, it also replicates the demographic profile expected for Brazil in 2050, when approximately one-third of its population will be over 60 years of age. The analyses confirm the current literature as they show an increase in healthcare plan usage by the elderly and the difference between admission rates by gender. They also reveal an increase in average length of stay in hospital and the increase in medical costs far above inflation, especially for materials and medicines. It is hoped that this study will help scholars and others interested in comparisons of medical expense trends, especially by age and sex, and that it encourages further collaboration on the sustainability of health insurance providers in Brazil

Doping the holographic Mott insulator

Mott insulators form because of strong electron repulsions, being at the heart of strongly correlated electron physics. Conventionally these are understood as classical "traffic jams" of electrons described by a short-ranged entangled product ground state. Exploiting the holographic duality, which maps the physics of densely entangled matter onto gravitational black hole physics, we show how Mott-insulators can be constructed departing from entangled non-Fermi liquid metallic states, such as the strange metals found in cuprate superconductors. These "entangled Mott insulators" have traits in common with the "classical" Mott insulators, such as the formation of Mott gap in the optical conductivity, super-exchange-like interactions, and form "stripes" when doped. They also exhibit new properties: the ordering wave vectors are detached from the number of electrons in the unit cell, and the DC resistivity diverges algebraically instead of exponentially as function of temperature. These results may shed light on the mysterious ordering phenomena observed in underdoped cuprates.Comment: 27 pages, 9 figures. Accepted in Nature Physic

Harnessing content and context for enhanced decision making

In a time in which a significant amount of interpersonal interactions take place online, one must enquire to which extent are these milieus suitable for supporting the complexity of our communication. This is especially important in more sensitive domains, such as the one of Online Dispute Resolution, in which inefficient communication environments may result in misunderstandings, poor decisions or the escalation of the conflict. The conflict manager, in particular, may find his skills severely diminished, namely in what concerns the accurate perception of the state of the parties. In this paper the development of a rich communication framework is detailed that conveys contextual information about their users, harnessed from the transparent analysis of their behaviour while communicating. Using it, the conflict manager may not only better perceive the conflict and how it affects each party but also take better contextualized decisions, closer to the ones taken in face-to-face settings.This work is part-funded by ERDF - European Regional Development Fund through the COMPETE Programme (operational programme for competitiveness) and by National Funds through the FCT { Fundação para a Ciência e a Tecnologia (Portuguese Foundation for Science and Technology) within project FCOMP-01-0124-FEDER-028980 (PTDC/EEI-SII/1386/2012) and project PEst- OE/EEI/UI0752/2014

Non-Fermi-liquid behavior in the Kondo lattices induced by peculiarities of magnetic ordering and spin dynamics

A scaling consideration of the Kondo lattices is performed with account of singularities in the spin excitation spectral function. It is shown that a non-Fermi-liquid (NFL) behavior between two critical values of the bare $s-f$ coupling constant occurs naturally for complicated magnetic structures with several magnon branches. This may explain the fact that a NFL behavior takes place often in the heavy-fermion systems with peculiar spin dynamics. Another kind of a NFL-like state (with different critical exponents) can occur for simple antiferromagnets with account of magnon damping, and for paramagnets, especially with two-dimensional character of spin fluctuations. The mechanisms proposed lead to some predictions about behavior of specific heat, resistivity, magnetic susceptibility, and anisotropy parameter, which can be verified experimentally.Comment: 16 pages, RevTeX, 4 Postscript figures. Extended versio

Post-Newtonian approximation for isolated systems calculated by matched asymptotic expansions

Two long-standing problems with the post-Newtonian approximation for isolated slowly-moving systems in general relativity are: (i) the appearance at high post-Newtonian orders of divergent Poisson integrals, casting a doubt on the soundness of the post-Newtonian series; (ii) the domain of validity of the approximation which is limited to the near-zone of the source, and prevents one, a priori, from incorporating the condition of no-incoming radiation, to be imposed at past null infinity. In this article, we resolve the problem (i) by iterating the post-Newtonian hierarchy of equations by means of a new (Poisson-type) integral operator that is free of divergencies, and the problem (ii) by matching the post-Newtonian near-zone field to the exterior field of the source, known from previous work as a multipolar-post-Minkowskian expansion satisfying the relevant boundary conditions at infinity. As a result, we obtain an algorithm for iterating the post-Newtonian series up to any order, and we determine the terms, present in the post-Newtonian field, that are associated with the gravitational-radiation reaction onto an isolated slowly-moving matter system.Comment: 61 pages, to appear in Phys. Rev.