26 research outputs found
Scalar-Tensor Models of Normal and Phantom Dark Energy
We consider the viability of dark energy (DE) models in the framework of the
scalar-tensor theory of gravity, including the possibility to have a phantom DE
at small redshifts as admitted by supernova luminosity-distance data. For
small , the generic solution for these models is constructed in the form of
a power series in without any approximation. Necessary constraints for DE
to be phantom today and to cross the phantom divide line at small
are presented. Considering the Solar System constraints, we find for the
post-Newtonian parameters that and for
the model to be viable, and (but very close to 1) if the model
has a significantly phantom DE today. However, prospects to establish the
phantom behaviour of DE are much better with cosmological data than with Solar
System experiments. Earlier obtained results for a -dominated universe
with the vanishing scalar field potential are extended to a more general DE
equation of state confirming that the cosmological evolution of these models
rule them out. Models of currently fantom DE which are viable for small can
be easily constructed with a constant potential; however, they generically
become singular at some higher . With a growing potential, viable models
exist up to an arbitrary high redshift.Comment: 30 pages, 4 figures; Matches the published version containing an
expanded discussion of various point
Numbers in the Blind's âEyeâ
Background: Although lacking visual experience with numerosities, recent evidence shows that the blind perform similarly to sighted persons on numerical comparison or parity judgement tasks. In particular, on tasks presented in the auditory modality, the blind surprisingly show the same effect that appears in sighted persons, demonstrating that numbers are represented through a spatial code, i.e. the Spatial-Numerical Association of Response Codes (SNARC) effect. But, if this is the case, how is this numerical spatial representation processed in the brain of the blind? Principal Findings: Here we report that, although blind and sighted people have similarly organized numerical representations, the attentional shifts generated by numbers have different electrophysiological correlates (sensorial N100 in the sighted and cognitive P300 in the blind). Conclusions: These results highlight possible differences in the use of spatial representations acquired through modalities other than vision in the blind population
M402, a Novel Heparan Sulfate Mimetic, Targets Multiple Pathways Implicated in Tumor Progression and Metastasis
Heparan sulfate proteoglycans (HSPGs) play a key role in shaping the tumor microenvironment by presenting growth factors, cytokines, and other soluble factors that are critical for host cell recruitment and activation, as well as promoting tumor progression, metastasis, and survival. M402 is a rationally engineered, non-cytotoxic heparan sulfate (HS) mimetic, designed to inhibit multiple factors implicated in tumor-host cell interactions, including VEGF, FGF2, SDF-1α, P-selectin, and heparanase. A single s.c. dose of M402 effectively inhibited seeding of B16F10 murine melanoma cells to the lung in an experimental metastasis model. Fluorescent-labeled M402 demonstrated selective accumulation in the primary tumor. Immunohistological analyses of the primary tumor revealed a decrease in microvessel density in M402 treated animals, suggesting anti-angiogenesis to be one of the mechanisms involved in-vivo. M402 treatment also normalized circulating levels of myeloid derived suppressor cells in tumor bearing mice. Chronic administration of M402, alone or in combination with cisplatin or docetaxel, inhibited spontaneous metastasis and prolonged survival in an orthotopic 4T1 murine mammary carcinoma model. These data demonstrate that modulating HSPG biology represents a novel approach to target multiple factors involved in tumor progression and metastasis
Bis-14-membered ring diketal diamines: Synthesis and evaluation of their anti-HIV and anti-tumoral activities
Chiral and achiral macrocyclic bis-diketal diamines, analogs of bicyclam AMD 3100, were synthesized in three steps from the previously obtained 14-membered ring diketal dilactams. Their monoreduction with lithium aluminium hydride gave the corresponding diketal aminolactams. Coupling these with dibromo-pxylene led to xylyl dimer compounds. A second reduction step yielded the expected bis-diketal diamines in the methyl and unsubstituted series. Biological tests on the unreduced and reduced dimers showed both weak anti-HIV and anti-proliferative activities for the bis-diphenyl diketal aminolactam 13b, with a mode of action probably different from that of AMD 3100. 1
Nouveaux ligands azotés polydentés : SynthÚse et étude de complexation de radionucléides.
Case Report: HĂ©mangiome vertĂ©brale gĂ©ant rĂ©vĂ©lĂ© par un traumatisme lombaire: Ă propos dâun cas
L'hĂ©mangiome vertebral est une tumeur bĂ©nigne frĂ©quente, c'est une lĂ©sion bĂ©nigne habituellement asymptomatique. Les formes Ă©volutives rĂ©sponsables de compression mĂ©dullaire sont beaucoup plus rares, une surveillance clinique et radiologique est conseillĂ©. Nous mettons en exergue Ă travers ce cas revelĂ© par des signes de compression mĂ©dullaire suite Ă une chute, l'intĂ©rĂȘt de l'imagerie en coupes dans le diagnostic positif ; pour dĂ©celer les formes compliquĂ©es, et pour orienter l'attitude thĂ©rapeutique. Les formes neurologiques nĂ©cessitent une prise en charge neurochirurgicale.Key words: HĂ©mangiome vertĂ©brale, compression mĂ©dullaire, traumatisme lombair