386 research outputs found
Reddening, Absorption, and Decline Rate Corrections for a Complete Sample of Type Ia Supernovae leading to a Fully Corrected Hubble Diagram to v<30,000kms-1
Photometric BVI and redshift data corrected for streaming motions are
compiled for 111 "Branch normal", 4 1991T-like, 7 1991bg-like, and 2 unusual
SNe Ia. Color excesses E(B-V)host of normal SNe Ia, due to the absorption of
the host galaxy, are derived by three independent methods leading to the
intrinsic colors at maximum of (B-V)00=-0.024, and (V-I)00=-0.265 if normalized
to a common decline rate of Dm_15=1.1. The strong correlation between redshift
absolute magnitudes (based on Ho=60), corrected only for the extrinsic Galactic
absorption, and the derived E(B-V)host leads to well determined, yet abnormal
absorption-to-reddening ratios of R_BVI=3.65, 2.65, and 1.35. Comparison with
the canonical Galactic values of 4.1, 3.1, 1.8 forces the conclusion that the
law of interstellar absorption in the path length to the SN in the host galaxy
is different from the local Galactic law. Improved correlations of the fully
corrected absolute magnitudes with host galaxy type, decline rate, and
intrinsic color are derived. The four peculiar 1991T-type SNe are significantly
overluminous as compared to Branch-normal SNe Ia. The overluminosity of the
seven 1999aa-like SNe is less pronounced. The seven 1991bg-types in the sample
constitute a separate class of SNeIa, averaging in B two magnitudes fainter
than the normal Ia. New Hubble diagrams in BVI are derived out to ~30,000kms-1
using the fully corrected magnitudes and velocities, corrected for streaming
motions. Nine solutions for the intercept magnitudes in these diagrams show
extreme stability at the 0.04 level using various subsamples of the data. The
same precepts for fully correcting SN magnitudes we shall use for the
luminosity recalibration of SNe Ia in the forthcoming final review of our HST
Cepheid-SN experiment for the Hubble constant.Comment: 49 pages, 15 figures, 8 tables, accepted for publication in the
Astrophysical Journa
Adding diphenyl diselenide in the diets of quails improves the quality of meat.
Abstract: Diphenyl diselenide (Ph2Se2) is an organic selenium compound that is known for its antioxidant characteristics. Thus, the aim of this study was to evaluate whether Ph2Se2 in quail (Coturnix japonica) diets influences the oxidative/antioxidant status and meat quality. Materials and methods. Four diets (0; 0.3; 0.6; 0.9 ppm Ph2Se2) were provided to 56 male quails (Coturnix japonica) distributed in a completely randomized design with 14 repetitions in order to check whether (PhSe)2 would change their blood and tissue oxidative/antioxidant status, which would lead to an improvement in the meat quality. Results. Adding Ph2Se2 in diets led to increased antioxidant activity of enzymes such as catalase, superoxide dismutase, and glutathione peroxidase, which consequently reduced oxidative levels in blood and tissues. Besides that, we observed an improvement in the quail meat quality; in other words, we observed an increased ability to hold water, a reduction in water loss from cooking, and reduced intensity of the yellow color in the breasts of birds that were fed with Ph2Se2. Conclusions. Therefore, we concluded that the antioxidant defense improvement in tissues that was provided by Ph2Se2 has a beneficial effect on meat quality. Resumen: El diseleniuro de difenilo (Ph2Se2) es un compuesto de selenio orgánico que es conocido por sus características antioxidantes. Por lo tanto, el objetivo de este estudio fue evaluar si Ph2Se2 en las dietas de codorniz (Coturnix japonica) influye en el estado oxidativo/antioxidante y la calidad de la carne. Materiales y métodos. Se proporcionaron cuatro dietas (0; 0.3; 0.6; 0.9 ppm Ph2Se2) a 56 codornices machos (Coturnix japonica) distribuidas en un diseño completamente aleatorizado con 14 repeticiones para verificar si Ph2Se2 cambiaría su sangre y tejido oxidativo/antioxidante, estado, lo que llevaría a una mejora en la calidad de la carne. Resultados. La adición de Ph2Se2 en las dietas provocó un aumento de la actividad antioxidante de enzimas como la catalasa, la superóxido dismutasa y la glutatión peroxidasa, lo que redujo los niveles de oxidación en la sangre y los tejidos. Además de eso, observamos una mejora en la calidad de la carne de codorniz; en otras palabras, observamos una mayor capacidad para retener agua, una reducción en la pérdida de agua debido a la cocción y una menor intensidad del color amarillo en las mamas de las aves que fueron alimentadas con Ph2Se2. Conclusiones. Por lo tanto, concluimos que la mejora de la defensa antioxidante en los tejidos proporcionada por Ph2Se2 tiene un efecto beneficioso sobre la calidad de la carne
Interacting Preformed Cooper Pairs in Resonant Fermi Gases
We consider the normal phase of a strongly interacting Fermi gas, which can
have either an equal or an unequal number of atoms in its two accessible spin
states. Due to the unitarity-limited attractive interaction between particles
with different spin, noncondensed Cooper pairs are formed. The starting point
in treating preformed pairs is the Nozi\`{e}res-Schmitt-Rink (NSR) theory,
which approximates the pairs as being noninteracting. Here, we consider the
effects of the interactions between the Cooper pairs in a Wilsonian
renormalization-group scheme. Starting from the exact bosonic action for the
pairs, we calculate the Cooper-pair self-energy by combining the NSR formalism
with the Wilsonian approach. We compare our findings with the recent
experiments by Harikoshi {\it et al.} [Science {\bf 327}, 442 (2010)] and
Nascimb\`{e}ne {\it et al.} [Nature {\bf 463}, 1057 (2010)], and find very good
agreement. We also make predictions for the population-imbalanced case, that
can be tested in experiments.Comment: 10 pages, 6 figures, accepted version for PRA, discussion of the
imbalanced Fermi gas added, new figure and references adde
Changes in Early Cortical Visual Processing Predict Enhanced Reactivity in Deaf Individuals
Individuals with profound deafness rely critically on vision to interact with their environment. Improvement of visual performance as a consequence of auditory deprivation is assumed to result from cross-modal changes occurring in late stages of visual processing. Here we measured reaction times and event-related potentials (ERPs) in profoundly deaf adults and hearing controls during a speeded visual detection task, to assess to what extent the enhanced reactivity of deaf individuals could reflect plastic changes in the early cortical processing of the stimulus. We found that deaf subjects were faster than hearing controls at detecting the visual targets, regardless of their location in the visual field (peripheral or peri-foveal). This behavioural facilitation was associated with ERP changes starting from the first detectable response in the striate cortex (C1 component) at about 80 ms after stimulus onset, and in the P1 complex (100–150 ms). In addition, we found that P1 peak amplitudes predicted the response times in deaf subjects, whereas in hearing individuals visual reactivity and ERP amplitudes correlated only at later stages of processing. These findings show that long-term auditory deprivation can profoundly alter visual processing from the earliest cortical stages. Furthermore, our results provide the first evidence of a co-variation between modified brain activity (cortical plasticity) and behavioural enhancement in this sensory-deprived population
TOMO-ETNA experiment at Etna volcano: Activities on land
In the present paper we describe the on-land field operations integrated in
the TOMO-ETNA experiment carried out in June-November 2014 at Mt.
Etna volcano and surrounding areas. This terrestrial campaign consists
in the deployment of 90 short-period portable three-component seismic
stations, 17 broadband seismometers and the coordination with 133 permanent
seismic station belonging to Italy’s Istituto Nazionale di Geofisica
e Vulcanologia (INGV). This temporary seismic network recorded active
and passive seismic sources. Active seismic sources were generated
by an array of air-guns mounted in the Spanish oceanographic vessel
“Sarmiento de Gamboa” with a power capacity of up to 5200 cubic
inches. In total more than 26,000 shots were fired and more than 450 local
and regional earthquakes were recorded. We describe the whole technical
procedure followed to guarantee the success of this complex seismic experiment.
We started with the description of the location of the potential
safety places to deploy the portable network and the products derived from
this search (a large document including full characterization of the sites,
owners and indication of how to arrive to them). A full technical description
of the seismometers and seismic sources is presented. We show
how the portable seismic network was deployed, maintained and recovered
in different stages. The large international collaboration of this experiment
is reflected in the participation of more than 75 researchers,
technicians and students from different institutions and countries in the
on-land activities. The main objectives of the experiment were achieved
with great success.PublishedS04272SR. VULCANI - Servizi e ricerca per la SocietàJCR Journalope
Does congenital deafness affect the structural and functional architecture of primary visual cortex?
Deafness results in greater reliance on the remaining senses. It is unknown whether the cortical architecture of the intact senses is optimized to compensate for lost input. Here we performed widefield population receptive field (pRF) mapping of primary visual cortex (V1) with functional magnetic resonance imaging (fMRI) in hearing and congenitally deaf participants, all of whom had learnt sign language after the age of 10 years. We found larger pRFs encoding the peripheral visual field of deaf compared to hearing participants. This was likely driven by larger facilitatory center zones of the pRF profile concentrated in the near and far periphery in the deaf group. pRF density was comparable between groups, indicating pRFs overlapped more in the deaf group. This could suggest that a coarse coding strategy underlies enhanced peripheral visual skills in deaf people. Cortical thickness was also decreased in V1 in the deaf group. These findings suggest deafness causes structural and functional plasticity at the earliest stages of visual cortex
Effect of Antihypertensive Therapy with Alpha Methyldopa on Levels of Angiogenic Factors in Pregnancies with Hypertensive Disorders
Antihypertensive drugs are believed to lower blood pressure in pre-eclampsia by direct or central vasodilatory mechanisms. However, they could also act by decreasing production of anti-angiogenic proteins involved in the pathophysiology of hypertension and proteinuria in pre-eclampsia (PE). The aim of our study was to evaluate the impact of antihypertensive therapy with alpha methyldopa on maternal circulating levels and placental production of soluble fms-like tyrosine kinase 1 (sFlt-1), soluble endoglin (sEng), vascular endothelial growth factor (VEGF) and placental growth factor (PlGF) in hypertensive disorders of pregnancy
Species richness in North Atlantic fish: Process concealed by pattern
International audiencePrevious analyses of marine fish species richness based on presence‐absence data have shown changes with latitude and average species size, but little is known about the underlying processes. To elucidate these processes we use metabolic, neutral and descriptive statistical models to analyse how richness responds to maximum species length, fish abundance, temperature, primary production, depth, latitude and longitude, while accounting for differences in species catchability, sampling effort and mesh size
- …