550 research outputs found
Continuous spectra in high-harmonic generation driven by multicycle laser pulses
We present observations of the emission of XUV continua in the 20-37 eV
region by high harmonic generation (HHG) with - pulses
focused onto a Kr gas jet. The underlying mechanism relies on coherent control
of the relative delays and phases between individually generated attosecond
pulse, achievable by adjusting the chirp of the driving pulses and the
interaction geometry. Under adequate negative chirp and phase matching
conditions, the resulting interpulse interference yields a continuum XUV
spectrum, which is due to both microscopic and macroscopic (propagation)
contributions. This technique opens the route for modifying the phase of
individual attosecond pulses and for the coherent synthesis of XUV continua
from multicycle driving laser pulses without the need of an isolated attosecond
burst.Comment: 14 pages, 5 figures. Submitted to Physical Review
Approach to the Lower Pliocene marine-continental correlation from southern Spain. The micrommamal site of Alhaurín el Grande-1 (Málaga Basin, Betic Cordillera, Spain)
A new micromammal site at Alhaurín el Grande (Málaga, southern Spain) located above early Pliocene marine deposits allows an approach to the marine-continental correlation for this age. The early Pliocene marine filling throughout the Málaga Basin is developed in three transgressive-regressive sequences (Pl-1, Pl-2, and Pl-3 units) bounded by discontinuities. At the top of the intermediate sequence Pl-2, peaty sediments have yielded fossils of Rodentia, Lagomorpha, Insectivora, and Crocodylia. The presence of Cricetus barrieri Mein & Michaux, 1970 in combination with murids, both of primitive morphology, such as Apodemus gudrunae Van de Weerd, 1976, and more advanced forms (i.e. Occitanomys brailloni Michaux, 1969 and Stephanomys donnezani cordii Ruiz Bustos, 1986), points to an early Ruscinian age (MN 14 biozone). Based on the planktonic foraminifers, the biostratigraphic data indicate that marine sediments just below the micromammal beds belong to the MPl-2 biozone of the early Zanclean. Available paleomagnetic data from the marine sediments show that the micromammal bed must be located between the normal geomagnetic subchron C3n3n (4.89-4.80 Ma) and the subchron C3n2n (4.63-4.49 Ma), limiting the age of this site to the late part of the early Zanclean
Tamarix minoa (Tamaricaceae), a new species from the island of Crete (Greece) based on morphological and plastid molecular sequence data
Tamarix minoa is described from material collected on the S Aegean island of Crete (Kriti), Greece. A morphological comparison with the species considered to be closest, T. africana and T. hampeana, is provided. An original illustration showing the main morphological characters of the new species is also given, as are photographs of the new species in its habitat. The isolated phylogenetic position of T. minoa is shown to be strongly supported by plastid molecular sequence data (trnS-trnG, trnQ-rps16 and ndhF-rpl32), thus warranting its recognition at specific rank.National Geographic Society, research project “Human recreation versus plant diversity on maritime sands in Crete” (NGS grant no. 8573-08). The FPU programme (Mº de Educación, Spain), the I+D+I project CGL2008-05056 (Mº de Educación y Ciencia, Spanish Government), the project OAPN 354-2011 (Mº de Agricultura, Alimentación y Medio Ambiente, Spanish Government) and complementary supporting funds ACIE10-01, ACIE11-05 and ACIE13-08 (University of Alicante, Spain)
Basement-Cover Relationships and Their Along-Strike Changes in the Linking Zone (Iberian Range, Spain): A Combined Structural and Gravimetric Study
Contractional deformation in the transition between the Iberian and Catalan Coastal Ranges (Linking Zone) generated both thin-skinned structures detached in low-strength Triassic units and basement-involved structures. To evaluate their extent and relative contribution to the overall structure, we carried out a study combining structural geology and gravimetry. New gravity data (938 stations) and density determinations (827 samples) were acquired and combined with previous existing databases to obtain Bouguer anomaly and residual Bouguer anomaly maps of the study area. Seven serial and balanced cross sections were built, their depth geometries being constrained through the 2.5-D gravity modeling and the 3-D gravity inversion that we accomplished. The residual Bouguer anomaly map shows a good correlation between basement antiforms and gravity highs whereas negative anomalies mostly correspond to (i) Meso-Cenozoic synclines and (ii) Neogene-Quaternary basins. Cross sections depict a southern, thick-skinned domain where extensional, basement faults inherited from Late Jurassic-Early Cretaceous times were inverted during the Cenozoic. To the north, we interpret the existence of both Triassic-detached and basement-involved deformation domains. The two deformation styles are vertically overlapped in the southernmost part of the Catalan Coastal Ranges but relay both across and along strike in the Eastern Iberian Range. These basement and cover relationships and their along-strike variations are analyzed in terms of the interplay between structural inheritance, its obliquity to the shortening direction, and the continuity and effectiveness of Triassic décollements in the study area
Deep XMM-Newton observation of the Eta Chamaleontis cluster
The members of the Eta Chamaleontis cluster are in an evolutionary stage in
which disks are rapidly evolving. It also presents some peculiarities, such as
the large fraction of binaries and accretion disks, probably related with the
cluster formation process. Its proximity makes this stellar group an ideal
target for studying the relation between X-ray emission and those stellar
parameters. The main objective of this work is to determine general X-ray
properties of the cluster members in terms of coronal temperature, column
density, emission measure, X-ray luminosity and variability. We also aim to
establish the relation between the X-ray luminosity of these stars and other
stellar parameters, such as binarity and presence of accretion disks. A study
of flare energies for each flare event and their relation with some stellar
parameters is also performed. We used proprietary data from a deep XMM-Newton
observation pointed at the core of the Eta Chamaleontis cluster. Specific
software for the reduction of XMM-Newton data was used for the analysis of our
observation. For the detection of sources, we used the wavelet-based code
PWDetect. General coronal properties were derived from plasma model fitting. We
also determined variability of the Eta Chamaleontis members in the EPIC
field-of-view. A total of six flare-like events were clearly detected in five
different stars. For them, we derived coronal properties during the flare
events and pseudo-quiescent state separately. In our observations, stars that
underwent a flare event have higher X-ray luminosities in the pseudo-quiescent
state than cluster members with similar spectral type with no indications of
flaring, independently whether they have an accretion disk or not. Observed
flare energies are typical of both pre-main and main-sequence M stars. We
detected no difference between flare energies of stars with and without an
accretion disk.Comment: Accepted for publication in Astronomy and Astrophysics. 12 pages, 30
individual figure
Protective Effect of Quercetin Treatment on Gut Microbiota Imbalance in Obesity-Associated NAFLD in Patients and in HFD-FED Mice
2 p.Gut microbiota is involved in obesity,
metabolic syndrome and nonalcoholic fatty liver disease
(NAFLD). Quercetin may modulate the intestinal microbiota
composition, suggesting therapeutic potential in NAFLD. The
present study aims to establish the role of gut microbiota imbalance
in obesity-related NAFLD development in patients and in
an in vivo model and to investigate benefits of experimental
treatment with quercetin. Resumen de un trabajo resultado del proyecto de investigación financiado por la Consejería de Educación de la Junta de Castilla y León (referencia LE063U16)S
Proliferación celular y metabolismo lipídico de células tumorales tratadas con el aceite esencial de un quimiotipo de <i>Lippia alba</i> procedente de Costa Rica
Lippia alba (Miller) N.E. Brown (Verbenaceae) es un arbusto aromático de amplia difusión en el continente americano muy utilizado en la medicina tradicional. Se la conoce como salvia morada o salvia de jardín, entre otros nombres. Su aceite esencial presenta una gran variabilidad química lo cual está relacionado con el origen geográfico de la planta. En Costa Rica se han identificado dos quimiotipos, un tipo denominado "dulce" rico en limoneno y carvona y uno denominado "fuerte" que presenta mayoritariamente ocimenona, mircenona, 1,8-cineol y mirceno. Se ha descrito que los terpenos presentes en algunos aceites esenciales tienen actividad antiproliferativa y podrían representar un nuevo aporte para la quimioprevención y tratamiento del cáncer. El objetivo de este trabajo fue estudiar los efectos del quimiotipo "fuerte" sobre el crecimiento celular y el metabolismo lipídico en células tumorales.Facultad de Ciencias Médica
Renal Function Impact in the Prognostic Value of Galectin-3 in Acute Heart Failure
[Abstract] Introduction: Galectin-3 (Gal-3) is an inflammatory marker associated with the development and progression of heart failure (HF). A close relationship between Gal-3 levels and renal function has been observed, but data on their interaction in patients with acute HF (AHF) are scarce. We aim to assess the prognostic relationship between renal function and Gal-3 during an AHF episode.
Materials and methods: This is an observational, prospective, multicenter registry of patients hospitalized for AHF. Patients were divided into two groups according to estimated glomerular filtration rate (eGFR): preserved renal function (eGFR ≥ 60 mL/min/1.73 m2) and renal dysfunction (eGFR <60 mL/min/1.73 m2). Cox regression analysis was performed to evaluate the association between Gal-3 and 12-month mortality.
Results: We included 1,201 patients in whom Gal-3 values were assessed at admission. The median value of Gal-3 in our population was 23.2 ng/mL (17.3-32.1). Gal-3 showed a negative correlation with eGFR (rho = -0.51; p < 0.001). Gal-3 concentrations were associated with higher mortality risk in the multivariate analysis after adjusting for eGFR and other prognostic variables [HR = 1.010 (95%-CI: 1.001-1.018); p = 0.038]. However, the prognostic value of Gal-3 was restricted to patients with renal dysfunction [HR = 1.010 (95%-CI: 1.001-1.019), p = 0.033] with optimal cutoff point of 31.5 ng/mL, with no prognostic value in the group with preserved renal function [HR = 0.990 (95%-CI: 0.964-1.017); p = 0.472].
Conclusions: Gal-3 is a marker of high mortality in patients with acute HF and renal dysfunction. Renal function influences the prognostic value of Gal-3 levels, which should be adjusted by eGFR for a correct interpretation.Grant No. RD06-0003-0000
Grant No. RD12/0042/000
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