11,839 research outputs found
High precision fundamental constants at the TeV scale
This report summarizes the proceedings of the 2014 Mainz Institute for
Theoretical Physics (MITP) scientific program on "High precision fundamental
constants at the TeV scale". The two outstanding parameters in the Standard
Model dealt with during the MITP scientific program are the strong coupling
constant and the top-quark mass . Lacking knowledge on the
value of those fundamental constants is often the limiting factor in the
accuracy of theoretical predictions. The current status on and
has been reviewed and directions for future research have been identified.Comment: 57 pages, 24 figures, pdflate
Milho Bt: vantagens para a cadeia produtiva e a viabilidade da coexistĂŞncia.
bitstream/item/35648/1/milho-bt.pd
Molecular mechanism of Gαi activation by non-GPCR proteins with a Gα-Binding and Activating motif
Heterotrimeric G proteins are quintessential signalling switches activated by nucleotide exchange on Gα. Although activation is predominantly carried out by G-protein-coupled receptors (GPCRs), non-receptor guanine-nucleotide exchange factors (GEFs) have emerged as critical signalling molecules and therapeutic targets. Here we characterize the molecular mechanism of G-protein activation by a family of non-receptor GEFs containing a Gα-binding and -activating (GBA) motif. We combine NMR spectroscopy, computational modelling and biochemistry to map changes in Gα caused by binding of GBA proteins with residue-level resolution. We find that the GBA motif binds to the SwitchII/α3 cleft of Gα and induces changes in the G-1/P-loop and G-2 boxes (involved in phosphate binding), but not in the G-4/G-5 boxes (guanine binding). Our findings reveal that G-protein-binding and activation mechanisms are fundamentally different between GBA proteins and GPCRs, and that GEF-mediated perturbation of nucleotide phosphate binding is sufficient for Gα activation
Magma displacements under insular volcanic fields, applications to eruption forecasting: El Hierro, Canary Islands, 2011-2013
Significant deformations, followed by increased seismicity detected since 2011 July at El Hierro, Canary Islands, Spain, prompted the deployment of additional monitoring equipment. The climax of this unrest was a submarine eruption first detected on 2011 October 10, and located at about 2 km SW of La Restinga, southernmost village of El Hierro Island. The eruption ceased on 2012 March 5, after the volcanic tremor signals persistently weakened through 2012 February. However, the seismic activity did not end with the eruption, as several other seismic crises followed. The seismic episodes presented a characteristic pattern: over a few days the number and magnitude of seismic event increased persistently, culminating in seismic events severe enough to be felt all over the island. Those crises occurred in 2011 November, 2012 June and September, 2012 December to 2013 January and in 2013 March-April. In all cases the seismic unrest was preceded by significant deformations measured on the island's surface that continued during the whole episode. Analysis of the available GPS and seismic data suggests that several magma displacement processes occurred at depth from the beginning of the unrest. The first main magma movement or 'injection' culminated with the 2011 October submarine eruption. A model combining the geometry of the magma injection process and the variations in seismic energy release has allowed successful forecasting of the new-vent opening.CSIC [2011-30E070]; MINECO [CGL2011-28682-C02-01]; bilateral UNAM (Mexico) - CSIC (Spain) program; Mayor's Office of El Pinar de El Hierroinfo:eu-repo/semantics/publishedVersio
Fusarium proliferatum isolated from garlic in Spain: Identification, toxigenic potential and pathogenicity on related Allium species
Fusarium proliferatum has been reported on garlic in the Northwest USA, Spain and Serbia, causing
water-soaked tan-colored lesions on cloves. In this work, Fusarium proliferatum was isolated from 300 symptomatic
garlic bulbs. Morphological identification of Fusarium was confirmed using species-specific PCR assays and EF-1α
sequencing. Confirmation of pathogenicity was conducted with eighteen isolates. Six randomly selected F. proliferatum
isolates from garlic were tested for specific pathogenicity and screened for fusaric acid production. Additionally,
pathogenicity of each F. proliferatum isolate was tested on healthy seedlings of onion (Allium cepa), leek (A.
porrum), scallions (A. fistulosum), chives (A. schoenoprasum) and garlic (A. sativum). A disease severity index (DSI)
was calculated as the mean severity on three plants of each species with four test replicates. Symptoms on onion
and garlic plants were observed three weeks after inoculation. All isolates tested produced symptoms on all varieties
inoculated. Inoculation of F. proliferatum isolates from diseased garlic onto other Allium species provided new
information on host range and pathogenicity. The results demonstrated differences in susceptibility with respect
to host species and cultivar. The F. proliferatum isolates tested all produced fusaric acid (FA); correlations between
FA production and isolate pathogenicity are discussed. Additionally, all isolates showed the presence of the FUM1
gene suggesting the ability of Spanish isolates to produce fumonisins
On the static solutions in gravity with massive scalar field in three dimensions
We investigate circularly symmetric static solutions in three-dimensional
gravity with a minimally coupled massive scalar field. We integrate numerically
the field equations assuming asymptotic flatness, where black holes do not
exist and a naked singularity is present. We also give a brief review on the
massless cases with cosmological constant.Comment: 11 pages, LaTeX, 1 Postscript figure. Some changes were don
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