163 research outputs found

    A dark energy multiverse

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    We present cosmic solutions corresponding to universes filled with dark and phantom energy, all having a negative cosmological constant. All such solutions contain infinite singularities, successively and equally distributed along time, which can be either big bang/crunchs or big rips singularities. Classicaly these solutions can be regarded as associated with multiverse scenarios, being those corresponding to phantom energy that may describe the current accelerating universe

    A graceful multiversal link of particle physics to cosmology

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    In this paper we work out a multiverse scenario whose physical characteristics enable us to advance the following the conjecture that whereas the physics of particles and fields is confined to live in the realm of the whole multiverse formed by finite-time single universes, that for our observable universe must be confined just in one of the infinite number of universes of the multiverse when such a universe is consistently referred to an infinite cosmic time. If this conjecture is adopted then some current fundamental problems that appear when one tries to make compatible particle physics and cosmology- such as that for the cosmological constant, the arrow of time and the existence of a finite proper size of the event horizon- can be solved.Comment: 10 pages, LaTe

    Speleoseismology and palaeoseismicity of Benis Cave (Murcia, SE Spain): coseismic effects of the 1999 Mula earthquake (mb 4.8)

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    This work describes the coseismic ceiling block collapse within Benis Cave (−213 m; Murcia, SE Spain), associated with the 1999 Mula earthquake (mb=4.8, MSK VII). The collapse occurred at −156 m into the Earthquake Hall, and as a consequence one small gallery became blind. We studied the geology, topography and active tectonic structures relevant to the cave. In addition, we carried out a seismotectonic analysis of the focal mechanism solutions, and also a fault population analysis on slickensides measured in fault planes in the cave. The stress and strain regime is interpreted as being congruent with the palaeoseismic evidence, and agrees with the fault kinematics established for cave galleries developed within fault planes and growth anomalies of coral flowstone. Our analysis suggests that one active segment (NNE–SSW) determined the morphology and topography of the Benis Cave, where strong to moderate palaeoearthquakes (6≤M≤7) took place. As a consequence of this intense seismic activity a small gallery collapsed. A new palaeoseismic structure, or seismothem, has been recognized, namely the effect of palaeoearthquakes affecting the pattern of development of the spatial coral flowstone distribution located at the bottom of the cave

    Criterios geomorfológicos sobre actividad tectónica reciente a lo largo de la Costa Recta, Isla Decepción (Antártida Occidental)

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    Several active tectonic evidences are observed along Costa Recta, located eastward of Deception Island (western Antarctica): marine terraces and fluvial streams cutting a relict glacier. The height of both landforms decrease southward from Macaroni Point, appointing to a tilt movement across a fault plane. Fault planes were measured at Macaroni Point and Baily Head, with a main NNWSSE orientation, similar to the Costa Recta strike. From several scales o f measure, the orientation of the beach was established in two principal segments: N168QE, and N173QE. On the other hand, the beach and glacier dynamics and sedimentary deposits were studied. According to the morpho-tectonic analysis, we conclude that the Costa Recta beach is a retreat scarp of a submarine fault oriented NNW-SSE and located in the Bransfield Strait, although a geophysical study o f the marine bottom is needed to map the fault trace in an accurate way

    Germline cdh1 g212e missense variant: Combining clinical, in vitro and in vivo strategies to unravel disease Burden

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    E-cadherin, encoded by CDH1, is an essential molecule for epithelial homeostasis, whose loss or aberrant expression results in disturbed cell–cell adhesion, increased cell invasion and metas-tasis. Carriers of CDH1 germline mutations have a high risk of developing diffuse gastric cancer and lobular breast cancer, associated with the cancer syndrome Hereditary Diffuse Gastric Cancer (HDGC). The ubiquitous availability of cancer panels has led to the identification of an increasing amount of “incidental” CDH1 genetic variants that pose a serious clinical challenge. This has sparked intensive research aiming at an accurate classification of the variants and consequent validation of their clinical relevance. The present study addressed the significance of a novel CDH1 variant, G212E, identified in an unusually large pedigree displaying strong aggregation of diffuse gastric cancer. We undertook a comprehensive pipeline encompassing family data, in silico predictions, in vitro assays and in vivo strategies, which validated the deleterious phenotype induced by this genetic alteration. In particular, we demonstrated that the G212E variant affects the stability and localization, as well as the adhesive and anti-invasive functions of E-cadherin, triggering epithelial disruption and disorganization. Our findings illustrate the clinical implication of a complementary approach for effective variant categorization and patient management.This work was financed by FEDER funds through the Operational Programme for Competitiveness Factors (COMPETE 2020), Programa Operacional de Competitividade e Inter-nacionalização (POCI) and Programa Operacional Regional do Norte (Norte 2020); and by National Funds through the Portuguese Foundation for Science and Technology (FCT) in the frame-work of the projects PTDC/MED-GEN/30356/2017, PTDC/BTM-SAL/30383/2017, PTDC/BIM-ONC/0281/2014, NORTE-01-0145-FEDER-000029, as well as doctoral grants SFRH/BD/108009/2015-S.M. and SFRH/BD/130708/2017-M.G. E.M.S. is funded by the “FCT Scientific Employment Stimulus—Individual Call” program (CEECIND/00622/2017). We acknowledge the American Association of Patients with Hereditary Gastric Cancer “No Stomach for Cancer” for funding Seruca’s and Figueiredo’s research

    Approach to the Spanish continental Neogene synthesis and paleoclimatic interpretation

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    Integrated studies on Neogene geology have been scarce in Spain, but attemps to stratigraphic and sedimentological analysis of continental Tertiary basins have increased considerably lately. The large extent of Neogene basins in Spain, the good quality of the outcrops and the abundance of fossil provide an excellent basis for this kind of studies

    Compilation of parameterized seismogenic sources in Iberia for the SHARE European-scale seismic source model.

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    Abstract: SHARE (Seismic Hazard Harmonization in Europe) is an EC-funded project (FP7) that aims to evaluate European seismic hazards using an integrated, standardized approach. In the context of SHARE, we are compiling a fully-parameterized active fault database for Iberia and the nearby offshore region. The principal goal of this initiative is for fault sources in the Iberian region to be represented in SHARE and incorporated into the source model that will be used to produce seismic hazard maps at the European scale. The SHARE project relies heavily on input from many regional experts throughout the Euro-Mediterranean region. At the SHARE regional meeting for Iberia, the 2010 Working Group on Iberian Seismogenic Sources (WGISS) was established; these researchers are contributing to this large effort by providing their data to the Iberian regional integrators in a standardized format. The development of the SHARE Iberian active fault database is occurring in parallel with IBERFAULT, another ongoing effort to compile a database of active faults in the Iberian region. The SHARE Iberian active fault database synthesizes a wide range of geological and geophysical observations on active seismogenic sources, and incorporates existing compilations (e.g., Cabral, 1995; Silva et al., 2008), original data contributed directly from researchers, data compiled from the literature, parameters estimated using empirical and analytical relationships, and, where necessary, parameters derived using expert judgment. The Iberian seismogenic source model derived for SHARE will be the first regional-scale source model for Iberia that includes fault data and follows an internationally standardized approach (Basili et al., 2008; 2009). This model can be used in both seismic hazard and risk analyses and will be appropriate for use in Iberian- and European-scale assessments

    280 one-opposition near-Earth asteroids recovered by the EURONEAR with the <i>Isaac Newton</i> Telescope

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    Context. One-opposition near-Earth asteroids (NEAs) are growing in number, and they must be recovered to prevent loss and mismatch risk, and to improve their orbits, as they are likely to be too faint for detection in shallow surveys at future apparitions. Aims. We aimed to recover more than half of the one-opposition NEAs recommended for observations by the Minor Planet Center (MPC) using the Isaac Newton Telescope (INT) in soft-override mode and some fractions of available D-nights. During about 130 h in total between 2013 and 2016, we targeted 368 NEAs, among which 56 potentially hazardous asteroids (PHAs), observing 437 INT Wide Field Camera (WFC) fields and recovering 280 NEAs (76% of all targets). Methods. Engaging a core team of about ten students and amateurs, we used the THELI, Astrometrica, and the Find_Orb software to identify all moving objects using the blink and track-and-stack method for the faintest targets and plotting the positional uncertainty ellipse from NEODyS. Results. Most targets and recovered objects had apparent magnitudes centered around V ~ 22.8 mag, with some becoming as faint as V ~ 24 mag. One hundred and three objects (representing 28% of all targets) were recovered by EURONEAR alone by Aug. 2017. Orbital arcs were prolonged typically from a few weeks to a few years; our oldest recoveries reach 16 years. The O−C residuals for our 1854 NEA astrometric positions show that most measurements cluster closely around the origin. In addition to the recovered NEAs, 22 000 positions of about 3500 known minor planets and another 10 000 observations of about 1500 unknown objects (mostly main-belt objects) were promptly reported to the MPC by our team. Four new NEAs were discovered serendipitously in the analyzed fields and were promptly secured with the INT and other telescopes, while two more NEAs were lost due to extremely fast motion and lack of rapid follow-up time. They increase the counting to nine NEAs discovered by the EURONEAR in 2014 and 2015. Conclusions. Targeted projects to recover one-opposition NEAs are efficient in override access, especially using at least two-meter class and preferably larger field telescopes located in good sites, which appear even more efficient than the existing surveys

    Phase II study of high-sensitivity genotyping of KRAS, NRAS, BRAF and PIK3CA to ultra-select metastatic colorectal cancer patients for panitumumab plus FOLFIRI: the ULTRA trial

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    Background: Several studies show the importance of accurately quantifying not only KRAS and other low-abundant mutations because benefits of anti-EGFR therapies may depend on certain sensitivity thresholds. We assessed whether ultra-selection of patients using a high-sensitive digital PCR (dPCR) to determine KRAS, NRAS, BRAF and PIK3CA status can improve clinical outcomes of panitumumab plus FOLFIRI. Patients and methods: This was a single-arm phase II trial that analysed 38 KRAS, NRAS, BRAF and PIK3CA hotspots in tumour tissues of irinotecan-resistant metastatic colorectal cancer patients who received panitumumab plus FOLFIRI until disease progression or early withdrawal. Mutation profiles were identified by nanofluidic dPCR and correlated with clinical outcomes (ORR, overall response rate; PFS, progression-free survival; OS, overall survival) using cut-offs from 0% to 5%. A quantitative PCR (qPCR) analysis was also performed. Results: Seventy-two evaluable patients were enrolled. RAS (KRAS/NRAS) mutations were detected in 23 (32%) patients and RAS/BRAF mutations in 25 (35%) by dPCR, while they were detected in 7 (10%) and 11 (15%) patients, respectively, by qPCR. PIK3CA mutations were not considered in the analyses as they were only detected in 2 (3%) patients by dPCR and in 1 (1%) patient by qPCR. The use of different dPCR cut-offs for RAS (KRAS/NRAS) and RAS/BRAF analyses translated into differential clinical outcomes. The highest ORR, PFS and OS in wild-type patients with their lowest values in patients with mutations were achieved with a 5% cut-off. We observed similar outcomes in RAS/BRAF wild-type and mutant patients defined by qPCR. Conclusions: High-sensitive dPCR accurately identified patients with KRAS, NRAS, BRAF and PIK3CA mutations. The optimal RAS/BRAF mutational cut-off for outcome prediction is 5%, which explains that the predictive performance of qPCR was not improved by dPCR. The biological and clinical implications of low-frequent mutated alleles warrant further investigations
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