1,336 research outputs found
Cool dwarfs in wide multiple systems. Paper 6: A curious quintuple system of a compact Sun-like triple and a close pair of an M dwarf and a very cool white dwarf at a wide separation
The system WDS 16329+0315 is an old, nearby quintuple physical system in the
thick Galactic disc formed by a close-resolved, triple primary of solar
metallicity, namely HD 149162, and a very wide, common proper motion, secondary
pair, formed by the mid-M dwarf G-17-23 and the white dwarf LSPM J1633+0311S.
We present an exhaustive astrometric and photometric data compilation of the
system, including Gaia DR2 parallaxes and proper motions, and the first
analysis of the nature of the faintest component. LSPM J1633+0311S (HD 149162
C) is a very cool white dwarf with an effective temperature of only about 5500
K, near the coolest end of the grid of theoretical models.Comment: The Observatory, in press, to appear in December 201
Two-zero textures for Dirac Neutrinos
We review the two-zero mass matrix textures approach for Dirac neutrinos with
the most recent global fit in the oscillation parameters. We found that three
of the 15 possible textures are compatible with current experimental data,
while the remaining two-zero textures are ruled out. Two textures are
consistent with the neutrino masses' normal hierarchy and are CP-conserving. At
the same time, the other one is compatible with both mass orderings and allows
for CP violation. We also present the correlations between the oscillation
parameters for the allowed two-zero textures.Comment: 8 pages, 4 figure
Efficacy of different recovery strategies in elite soccer players
Una correcta estrategia de recuperación (ER) tras la competición o el entrenamiento de alta intensidad en fútbol ayudará a no disminuir el rendimiento y a prevenir lesiones. El objetivo de este trabajo fue estudiar la eficacia de diferentes estrategias de recuperación combinadas en comparación con una simple, tras una sesión de entrenamiento específico de fútbol. Participaron 20 jugadores de fútbol de élite y se utilizaron cuatro estrategias de recuperación de forma aleatoria y contrabalanceada a lo largo de 4 semanas de entrenamiento. Se midió temperatura timpánica y las escalas subjetiva Total
Quality Recovery (TQR) y Category Ratio Scale (CR10). Los resultados exponen que ninguna de las ER estudiadas muestra ser más eficaz que las demás. No obstante, la realización de protocolos de recuperación combinados llevados a cabo tras la sesión de entrenamiento de fútbol, tiende a una mayor eficacia respecto al protocolo que incluía únicamente estiramientosAfter a soccer match or high intensity training, suitable recovery will help not to decrease performance and to prevent injuries. The aim of this study was to test the effectiveness of different combined recovery strategies in comparison with a simple one, after a specific soccer training session. Twenty elite players participated in the study. A randomized crossover design was used to determine the effect of 4 post-training session recovery strategies. Tympanic temperature was measured, as well as Total Quality Recovery (TQR) and Category Ratio Scale (CR10) subjective scales. Results show that none of the recovery strategies proved more effective than others. However, the use of combined strategies tended to be more effective than a simple strategy after a high intensity training session in socce
Antioxidant activity, phenolic compounds and colour of red wines treated with new fining agents
Nowadays the clarification and stabilization of red wines is generally done with conventional fining agents, like bentonite and activated coal, which pose a major challenge to environmental security and wastes management. This stimulated the use of many new techniques in order to discover alternative fining agents that don’t have negative influence on color, phenolic compounds and quality parameters. The aim of this research is to determine, how alternative fining agents, in different doses, affect antioxidant activity and colour parameters of 'Cabernet Sauvignon' red wines. Experimental material is from North-East Romania and was fined with mesoporous materials, bentonite and activated coal. Discriminant analysis classified 'Cabernet Sauvignon' wines according to the different fining agents based on total polyphenolic compounds and total antioxidant activity. Alternative fining agents, as mesoporous materials, have less impact on the colour and phenolic content of red wines in contrast to activated coal and bentonite treatments that can conduct to unsatisfying characteristics. Mesoporous materials are preferable and could be an exceptional adsorbent for polyphenolic compounds
Ventricular fusion during auricular entrainment of idiopathic fascicular tachycardias. Implications on ventricular tachycardia circuit
Closing the dark photon window to thermal dark matter
The nature of dark matter remains a central question in particle physics,
cosmology, and astrophysics. The prevailing hypothesis postulates that dark
matter consists of particles that interact only weakly with Standard Model
particles. However, the knowledge of dark matter properties beyond these
interactions is limited. This study explores a scenario involving a dark photon
as a mediator between dark matter and the Standard Model, akin to the photon's
role in electromagnetism. Recent cosmological and experimental evidence impose
constraints on this scenario, focusing on results from direct detection
experiments such as PICO-60, XENON-1T, and PANDAX-4T. The results reveal severe
constraints, effectively closing the window for laboratory searches for dark
photons as mediators between the Standard Model and the dark sector (dark
electrons) in the secluded dark matter scenario. The findings underscore the
need for alternative explanations and offer fresh perspectives on the ongoing
quest to understand dark matter and its interactions since they are nearly
independent of the dark electron fraction content for the total dark matter.
This analysis significantly narrows down the parameter space for thermal dark
matter scenarios involving a dark photon portal, reinforcing the urgency of
exploring alternative models and designing new experiments to unravel the
mysteries surrounding the nature of dark matter.Comment: 11 pages, 5 figure
S_3-flavour symmetry as realized in lepton flavour violating processes
A variety of lepton flavour violating effects related to the recent discovery
of neutrino oscillations and mixings is here systematically discussed in terms
of an S_3-flavour permutational symmetry. After a brief review of some relevant
results on lepton masses and mixings, that had been derived in the framework of
a Minimal S_3-Invariant Extension of the Standard Model, we derive explicit
analytical expressions for the matrices of the Yukawa couplings and compute the
branching ratios of some selected flavour changing neutral current (FCNC)
processes, as well as, the contribution of the exchange of neutral flavour
changing scalars to the anomaly of the muon's magnetic moment as functions of
the masses of the charged leptons and the neutral Higgs bosons. We find that
the S_3 x Z_2 flavour symmetry and the strong mass hierarchy of the charged
leptons strongly suppress the FCNC processes in the leptonic sector well below
the present experimental upper bounds by many orders of magnitude. The
contribution of FCNC to the anomaly of the muon's magnetic moment is small but
non-negligible.Comment: 23 pages, one figure. To appear in J. Phys A: Mathematical and
Theoretical (SPE QTS5
Anticitrullinated peptide antibodies (ACPA) in the serum of heavy smokers without arthritis - a differential role of associated pulmonary disease?
2 páginas, 1 tabla.-- Póster presentado al 5º European Workshop on Immune-Mediated Inflammatory Diseases celebrado en Sitges (Barcelona) del 1 al 3 de Diciembre de 2010.An increased risk of RA has been described in smokers,
but only in ACPA-positive RA patients. The frequency
of ACPA in serum of heavy smokers is not known.Peer reviewe
Proteomic profiling of retinoblastoma-derived exosomes reveals potential biomarkers of vitreous seeding
Retinoblastoma (RB) is the most common tumor of the eye in early childhood. Although recent advances in conservative treatment have greatly improved the visual outcome, local tumor control remains difficult in the presence of massive vitreous seeding. Traditional biopsy has long been considered unsafe in RB, due to the risk of extraocular spread. Thus, the identification of new biomarkers is crucial to design safer diagnostic and more effective therapeutic approaches. Exosomes, membrane-derived nanovesicles that are secreted abundantly by aggressive tumor cells and that can be isolated from several biological fluids, represent an interesting alternative for the detection of tumor-associated biomarkers. In this study, we defined the protein signature of exosomes released by RB tumors (RBT) and vitreous seeding (RBVS) primary cell lines by high resolution mass spectrometry. A total of 5666 proteins were identified. Among these, 5223 and 3637 were expressed in exosomes RBT and one RBVS group, respectively. Gene enrichment analysis of exclusively and differentially expressed proteins and network analysis identified in RBVS exosomes upregulated proteins specifically related to invasion and metastasis, such as proteins involved in extracellular matrix (ECM) remodeling and interaction, resistance to anoikis and the metabolism/catabolism of glucose and amino acids
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