Constraining Variations in the Fine Structure Constant in the presence of Early Dark Energy

We discuss present and future cosmological constraints on variations of the fine structure constant $\alpha$ induced by an early dark energy component having the simplest allowed (linear) coupling to electromagnetism. We find that current cosmological data show no variation of the fine structure constant at recombination respect to the present-day value, with $\alpha$ / $\alpha_0$ = 0.975 \pm 0.020 at 95 % c.l., constraining the energy density in early dark energy to $\Omega_e$ < 0.060 at 95 % c.l.. Moreover, we consider constraints on the parameter quantifying the strength of the coupling by the scalar field. We find that current cosmological constraints on the coupling are about 20 times weaker than those obtainable locally (which come from Equivalence Principle tests). However forthcoming or future missions, such as Planck Surveyor and CMBPol, can match and possibly even surpass the sensitivity of current local tests.Comment: 5 pages, 3 figure

O problema da pesagem de bovinos no campo e o melhoramento genético.

O melhoramento genético utiliza dados de pesos ao nascimento, desmama, doze meses e aos dezoito meses para estimar componentes de variância e outros parâmetros genético afins

Estaquia de erva-mate.

bitstream/item/215499/1/circ-tec18.pd

Enraizamento de estacas de Eucalyptus dunnii Maiden.

bitstream/item/214849/1/circ-tec22.pd

Dilepton distributions at backward rapidities

The dilepton production at backward rapidities in $pAu$ and $pp$ collisions at RHIC and LHC energies is investigated in the dipole approach. The results are shown through the nuclear modification ratio $R_{pA}$ considering transverse momentum and rapidity spectra. The dilepton modification ratio presents interesting behavior at the backward rapidities when compared with the already known forward ones, since it is related with the large $x$ kinematical region that is being probed. The rapidity dependence of the nuclear modification ratio in the dilepton production is strongly dependent on the Bjorken $x$ behavior of the nuclear structure function ratio $R_{F_{2}}=F_{2}^{A}/F_{2}^{p}$. The $R_{pA}$ transverse momentum dependence at backward rapidities is modified due to the large $x$ nuclear effects: at RHIC energies, for instance, the ratio $R_{pA}$ is reduced as $p_T$ increases, presenting an opposite behavior when compared with the forward one. It implies that the dilepton production at backward rapidities should carry information of the nuclear effects at large Bjorken $x$, as well as that it is useful to investigate the $p_T$ dependence of the observables in this kinematical regime.Comment: 15 pages, 6 figures. Version published in the Phys. Rev.

Synthesis and investigation of phthalocyanine-biotin conjugates

An isothiocyanato-functionalized phthalocyanine (Pc) was synthesized in good yield from the corresponding amine-substituted Pc. This Pc reacted with ethanolamine, biotin hydrazine, and biotin diethylamine under mild conditions (room temperature in DMF or DMSO in the presence of TEA) to produce the corresponding thiourea products in 60-75% yields. All Pcs showed intense Q absorptions in DMF around 677 nm, emissions centered at 683 nm, and fluorescence quantum yields in the range 0.18-0.27. The Pcs were phototoxic to human carcinoma HEp2 cells (IC50 similar to 7 at 1.5 J/cm(2)) and localized in multiple organelles, including the lysosomes, Golgi and ER. One biotin-Pc conjugate was injected via tail vein into nude mice bearing HT-29 tumors and demonstrated selective localization in the tumor tissue

Micropropagação de Eucalyptus citriodora e Eucalyptus tereticornis.

Edição dos Anais do Congresso Florestal Brasileiro, 6., 1990, Campos do Jordão

Endothelial Jagged1 promotes solid tumor growth through both pro-angiogenic and angiocrine functions

Angiogenesis is an essential process required for tumor growth and progression. The Notch signaling pathway has been identified as a key regulator of the neo-angiogenic process. Jagged-1 (Jag1) is a Notch ligand required for embryonic and retinal vascular development, which direct contribution to the regulation of tumor angiogenesis remains to be fully characterized. The current study addresses the role of endothelial Jagged1-mediated Notch signaling in the context of tumoral angiogenesis in two different mouse tumor models: subcutaneous Lewis Lung Carcinoma (LLC) tumor transplants and the autochthonous Transgenic Adenocarcinoma of the Mouse Prostate (TRAMP). The role of endothelial Jagged1 in tumor growth and neo-angiogenesis was investigated with endothelial-specific Jag1 gain- and loss-of-function mouse mutants (eJag1OE and eJag1cKO). By modulating levels of endothelial Jag1, we observed that this ligand regulates tumor vessel density, branching, and perivascular maturation, thus affecting tumor vascular perfusion. The pro-angiogenic function is exerted by its ability to positively regulate levels of Vegfr-2 while negatively regulating Vegfr-1. Additionally, endothelial Jagged1 appears to exert an angiocrine function possibly by activating Notch3/Hey1 in tumor cells, promoting proliferation, survival and epithelial-to-mesenchymal transition (EMT), potentiating tumor development. These findings provide valuable mechanistic insights into the role of endothelial Jagged1 in promoting solid tumor development and support the notion that it may constitute a promising target for cancer therapy