Vortex Lattice in Bi_{2}Sr_{2}CaCu_{2}O_{8+\delta} Well Above the First-Order Phase-Transition Boundary

Measurements of non-local in-plane resistance originating from transverse vortex-vortex correlations have been performed on a Bi_{2}Sr_{2}CaCu_{2}O_{8+\delta} high-T_c superconductor in a magnetic field up to 9 T applied along the crystal c-axis. Our results demonstrate that a rigid vortex lattice does exist over a broad portion of the magnetic field -- temperature (H-T) phase diagram, well above the first-order transition boundary H_{FOT}(T). The results also provide evidence for the vortex lattice melting and vortex liquid decoupling phase transitions, occurring above the H_{FOT}(T).Comment: 14 pages, 10 figure

Climate change in Central and South America: Recent trends, future projections, and impacts on regional agriculture

This report investigates the climate of two target regions of the CGIAR Research Program on Climate Change, Agriculture and Food Security (CCAFS): Central and South America (CA and SA, respectively). The report assesses the implications of climate change for agriculture, with a particular focus on those aspects of climate change that will have greatest impact on the crops currently grown in each region. The study investigated the ability of General Circulation Models (GCMs) and downscaled climate change scenarios to reproduce already observed climates, to establish the reliability of future climate projections, as well as projections of how associated crops might grow under future conditions

Posição prona como estratégia ventilatória em pacientes com lesão pulmonar aguda e síndrome da angústia respiratória aguda

Prone position seems to be a promissing strategy to improve the hypoxemia in patients with acute lung injury and severe acute respiratory distress syndrome. Previous works have shown that, while in prone position, there is a ventilation of areas that once were in atelectasis. This ventilation is accompanied by a redistribution of blood flow, with a reduction of the intrapulmonary shunt and, therefore, an improvement of the ventilation/ perfusion relation. The authors review the use of prone position, its indications and contraindications, as well as the mechanisms involved in the oxygenation improvement.A posição prona parece ser uma estratégia promissora para melhorar a hipoxemia em pacientes com lesão pulmonar aguda e síndrome da angústia respiratória aguda. Estudos realizados têm demonstrado que, durante sua aplicação, ocorre a ventilação de áreaspreviamente atelectasiadas, o que se acompanha de redistribuição do fluxo sangüíneo, com redução do shunt intrapulmonar e conseqüente melhora na relação ventilação/ perfusão. Os autores fazem uma revisão sobre o uso da posição prona, suas indicaçõese contra-indicações, bem como os mecanismos envolvidos na melhora da oxigenação

Phantom Cosmology with Non-minimally Coupled Real Scalar Field

We find that the expansion of the universe is accelerating by analyzing the recent observation data of type \textsc{I}a supernova(SN-Ia) .It indicates that the equation of state of the dark energy might be smaller than -1,which leads to the introduction of phantom models featured by its negative kinetic energy to account for the regime of equation of state parameter $w<-1$.In this paper the possibility of using a non-minimally coupled real scalar field as phantom to realize the equation of state parameter $w<-1$ is discussed.The main equations which govern the evolution of the universe are obtained.Then we rewrite them with the observable quantities.Comment: 12 pages, 2 figures. Accepted for publication in Gen.Rel.Gra

Phantom Field with O(N) Symmetry in Exponential Potential

In this paper, we study the phase space of phantom model with O(\emph{N}) symmetry in exponential potential. Different from the model without O(\emph{N}) symmetry, the introduction of the symmetry leads to a lower bound $w>-3$ on the equation of state for the existence of stable phantom dominated attractor phase. The reconstruction relation between the potential of O(\textit{N}) phantom system and red shift has been derived.Comment: 5 pages, 3 figures, replaced with the version to appear on Phys. Rev.

Late-time cosmology in (phantom) scalar-tensor theory: dark energy and the cosmic speed-up

We consider late-time cosmology in a (phantom) scalar-tensor theory with an exponential potential, as a dark energy model with equation of state parameter close to -1 (a bit above or below this value). Scalar (and also other kinds of) matter can be easily taken into account. An exact spatially-flat FRW cosmology is constructed for such theory, which admits (eternal or transient) acceleration phases for the current universe, in correspondence with observational results. Some remarks on the possible origin of the phantom, starting from a more fundamental theory, are also made. It is shown that quantum gravity effects may prevent (or, at least, delay or soften) the cosmic doomsday catastrophe associated with the phantom, i.e. the otherwise unavoidable finite-time future singularity (Big Rip). A novel dark energy model (higher-derivative scalar-tensor theory) is introduced and it is shown to admit an effective phantom/quintessence description with a transient acceleration phase. In this case, gravity favors that an initially insignificant portion of dark energy becomes dominant over the standard matter/radiation components in the evolution process.Comment: LaTeX file, 48 pages, discussion of Big Rip is enlarged, a reference is adde

Antitumoral, antileishmanial and antimalarial activity of pentacyclic 1,4-naphthoquinone derivatives

Pterocarpanquinones 8a-c, previously synthesized in our laboratory, and an homologous series of derivatives, compounds 9a-c prepared in this work, were evaluated on breast cancer cells (MCF-7) and on the parasites Leishmania amazonensis and Plasmodium falciparum, in culture. Compounds 8a-c were more potent than 9a-c on tumor cells and Leishmania amazonensis. On the other hand, 9a-c showed to be more active on Plasmodium falciparum. All the compounds studied were bioselective, presenting negligible cytotoxicity against fresh murine lymphocytes and human lymphocytes activated by the mitogen phytohemaglutinin (PHA)

Equation of State of Oscillating Brans-Dicke Scalar and Extra Dimensions

We consider a Brans-Dicke scalar field stabilized by a general power law potential with power index $n$ at a finite equilibrium value. Redshifting matter induces oscillations of the scalar field around its equilibrium due to the scalar field coupling to the trace of the energy momentum tensor. If the stabilizing potential is sufficiently steep these high frequency oscillations are consistent with observational and experimental constraints for arbitrary value of the Brans-Dicke parameter $\omega$. We study analytically and numerically the equation of state of these high frequency oscillations in terms of the parameters $\omega$ and $n$ and find the corresponding evolution of the universe scale factor. We find that the equation of state parameter can be negative and less than -1 but it is not related to the evolution of the scale factor in the usual way. Nevertheless, accelerating expansion is found for a certain parameter range. Our analysis applies also to oscillations of the size of extra dimensions (the radion field) around an equilibrium value. This duality between self-coupled Brans-Dicke and radion dynamics is applicable for $\omega= -1 + 1/D$ where D is the number of extra dimensions.Comment: 10 two-column pages, RevTex4, 8 figures. Added clarifying discussions, new references. Accepted in Phys. Rev. D (to appear

Evapotranspiração E Coeficiente De Cultura Da Alstroemeria (alstroemeria × Hybrida) Cultivada Em Estufa

The determination of water requirements of a crop throughout its cycle is critical for a proper irrigation management. The objective of this study was to determine the evapotranspiration and crop coefficient (Kc) of Alstroemeria × hybrida grown under greenhouse conditions. The crop evapotranspiration (ETc) was determined by weighing lysimeters, and the reference evapotranspiration (ETo) was estimated by the Penman-Monteith method. The Experiment was conducted under controlled conditions at the Polytechnic College of UFSM, Santa Maria, RS, and the treatment comprised five depths for water replacement associated to the pot retention capacity (WHC) (30, 45, 60, 75 and 90% of WHC). The experimental design adopted was completely randomized, with ten repetitions, one plant per pot. For the evaluation of Kc, 90% of the container capacity was consideredas limit. The crop coefficient was obtained by the relationship between the crop evapotranspiration and reference evapotranspiration. Our results demonstrated that water consumption for Alstroemeria × hybrida in the treatments with a limit of water availability varied from 47.6 mm to 207.8 mm. The average crop coefficient of Alstroemeria × hybrida grown under greenhouse conditions was 0.39 for the growth stages, 0.41 for the beginning of flowering, 0.95 for flowering, and1.50 and 0.75 for full flowering and for the end of the flowering, respectively. © 2016, Universidade Estadual Paulista - UNESP. All rights reserved.21481782