234 research outputs found
Cosmology in GSG
We describe what cosmology looks like in the context of the geometric theory
of gravity (GSG) based on a single scalar field. There are two distinct classes
of cosmological solutions. An interesting feature is the possibility of having
a bounce without invoking exotic equations of state for the cosmic fluid. We
also discuss cosmological perturbation and present the basis of structure
formation by gravitational instability in the framework of the geometric scalar
gravity.Comment: 12 pages, 5 figures, accepted for publication in Phys. Rev.
More about scalar gravity
We discuss a class of models for gravity based on a scalar field. The models
include and generalize the old approach by Nordstr\"om which predated and in
some way inspired General Relativity. The class include also a model that we
have recently introduced and discussed in its cosmological aspects (GSG). We
present here a complete characterisation of the Schwarschild geometry as a
vacuum solution of GSG and sketch a discussion of the first Post-Newtonian
approximation.Comment: 11 pages, 1 figure, accepted for publication in PR
Geometric scalar theory of gravity
We present a geometric scalar theory of gravity. Our proposal will be
described using the "background field method" introduced by Gupta, Feynman and
others as a field theory formulation of general relativity. We analyze previous
criticisms against scalar gravity and show how the present proposal avoids
these difficulties. This concerns not only the theoretical complaints but also
those related to observations. In particular, we show that the widespread
belief of the conjecture that the source of scalar gravity must be the trace of
the energy-momentum tensor - which is one of the main difficulties to couple
gravity with electromagnetic phenomenon in previous models - does not apply to
our geometric scalar theory. Some consequences of the new scalar theory are
explored.Comment: We did some modifications which do not change the content of the tex
XPS analysis of Fe2O3-TiO2-Au nanocomposites prepared by a plasma-assisted route
Fe2O3 nanodeposits have been grown on fluorine-doped tin oxide (FTO) substrates by plasma
enhanced-chemical vapor deposition (PE-CVD). Subsequently, the obtained systems have been
functionalized through the sequential introduction of TiO2 and Au nanoparticles (NPs) by means of
radio frequency (RF)-sputtering. The target nanocomposites have been specifically optimized in
view of their ultimate functional application in solar-driven H2 generation. In the present study, our
attention is focused on a detailed X-ray photoelectron spectroscopy (XPS) characterization of the
surface composition for a representative Fe2O3-TiO2-Au specimen. In particular, this report
provides a detailed discussion of the analyzed C 1s, O 1s, Fe 2p, Ti 2p, and Au 4f regions. The
obtained results point to the formation of pure Fe2O3-TiO2-Au composites, with gold present only
in its metallic state and each of the constituents maintaining its chemical identity
Genomic organization and cytokine-mediated inducibility of the human TRIM-8/Gerp gene.
Cytokine signaling is negatively regulated by a set of SH2 domain-containing proteins, the Suppressors of Cytokine Signaling (SOCS) acting as intracellular modulators. Experimental evidence indicates that SOCS gene expression is induced by cytokines and pro-inflammatory stimuli and is highly controlled both at transcription and translation level. Furthermore, SOCS proteins appear rapidly degraded inside the cells, mostly controlling their stability by interacting with specific molecules such as elongin B and C. It has been shown that SOCS-1/JAB, a member of the SOCS family, interacts with TRIM-8/Gerp, a new ring protein specifically binding SOCS-1 recombinant polypeptide in-vitro and in-vivo. Trim-8/Gerp, transcribes a 3.0-kb mRNA, spans 551 AA and is highly conserved during evolution. In addition, it can be induced by IFN-γ in epithelial and lymphoid cells and is expressed mostly ubiquitously in murine and human tissues. Here in this report we present the genomic organization of this new SOCS-1 interactor, and we add new tools for extending investigation of the complex mechanism that undergoes negatively regulation of cytokine signaling
Geometric Scalar Gravity
We review the main properties of the recently proposed the Geometric Scalar Gravity (GSG), emphasizing its agreement with classical tests of the gravitational field in the solar system and the amplitude of the gravitational radiation
Different subcellular localisations of TRIM22 suggest species-specific function
The B30.2/SPRY domain is present in many proteins, including various members of the tripartite motif (TRIM) protein family such as TRIM5α, which mediates innate intracellular resistance to retroviruses in several primate species. This resistance is dependent on the integrity of the B30.2 domain that evolves rapidly in primates and exhibits species-specific anti-viral activity. TRIM22 is another positively selected TRIM gene. Particularly, the B30.2 domain shows rapid evolution in the primate lineage and recently published data indicate an anti-viral function of TRIM22. We show here that human and rhesus TRIM22 localise to different subcellular compartments and that this difference can be assigned to the positively selected B30.2 domain. Moreover, we could demonstrate that amino acid changes in two variable loops (VL1 and VL3) are responsible for the different subcellular localisations
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