1,391 research outputs found
Ocular Refraction at Birth and Its Development During the First Year of Life in a Large Cohort of Babies in a Single Center in Northern Italy
The purpose of this study was to investigate refraction at birth and during the first year of life in a large cohort of babies born in a single center in Northern Italy. We also aimed to analyze refractive errors in relation to the gestational age at birth. An observational ophthalmological assessment was performed within 24 h of birth on 12,427 newborns. Refraction was examined using streak retinoscopy after the administration of tropicamide (1%). Values in the range of between +0.50 ≤ D ≤ +4.00 were defined as physiological refraction at birth. Newborns with refraction values outside of the physiological range were followed up during the first year of life. Comparative analyses were conducted in a subgroup of babies with known gestational ages. The following distribution of refraction at birth was recorded: 88.03% of the babies had physiological refraction, 5.03% had moderate hyperopia, 2.14% had severe hyperopia, 3.4%, had emmetropia, 0.45%, had myopia, 0.94% had astigmatism, and 0.01% had anisometropia. By the end of the first year of life, we observed reductions in hyperopia and astigmatism, and stabilization of myopia. Preterm babies had a four-fold higher risk of congenital myopia and a three-fold higher risk of congenital emmetropia as compared to term babies. Refraction profiles obtained at birth changed during the first year of life, leading to a normalization of the refraction values. Gestational age at birth affected the incidence of refractive errors and amblyopia
Effects of orexins on 17β-estradiol synthesis and P450 aromatase modulation in the testis of alpaca (Vicugna pacos).
The steroidogenic enzyme P450 aromatase (ARO) has a key role in the conversion of testosterone (T) into estrogens (E), expressed as 17β-estradiol. The presence and localization of this key enzyme have not been described before in the South American camelid alpaca (Vicugna pacos). In our previous studies of the expression and biological effects of orexin A (OxA) and OxB on the alpaca testis demonstrated that OxA, via its specific receptor 1 (OX1R), stimulated T synthesis. In order to extend these findings, we presently explored the presence and localization of ARO in the alpaca male gonad, and the possible correlation between ARO and the orexinergic complex. Western blotting and immunohistochemistry demonstrated the presence of ARO in tissue homogenates and its localization in the tubular and interstitial compartments of the alpaca testis, respectively. The addition of OxA to fresh testicular slices decreased the 17β-estradiol E levels. This effect was annulled by the sequential addition of the selective OX1R antagonist, SB-408124. OxB incubation did not have any effect on the biosynthesis of E. Furthermore, the OxA-mediated down-regulation of E secretion could be ascribed to ARO inhibition by exogenous OxA, as indicated by measurement of ARO activity in tissue slices incubated with OxA. Overall, our findings suggest that locally secreted OxA interacting with OX1R could indirectly inhibit ARO activity, disabling the conversion of T to E, and consequently lowering E biosynthesis and increasing the production of T in mammalian testis
Molecular gas in the northern nucleus of Mrk273: Physical and chemical properties of the disk and its outflow
Aiming to characterise the properties of the molecular gas in the
ultraluminous infrared galaxy Mrk273 and its outflow, we used the NOEMA
interferometer to image the dense gas molecular tracers HCN, HCO+, HNC, HOC+
and HC3N at 86GHz and 256GHz with angular resolutions of 4.9x4.5 arcsec
(3.7x3.4 kpc) and 0.61x0.55 arcsec (460x420 pc). We also modelled the flux of
several H2O lines observed with Herschel using a radiative transfer code that
includes excitation by collisions as well as by far-infrared photons. The disk
of the Mrk273 north nucleus has two components with decoupled kinematics. The
gas in the outer parts (1.5 kpc) rotates with a south-east to north-west
direction, while in the inner disk (300 pc) follows a north-east to south-west
rotation. The central 300 pc, which hosts a compact starburst region, is filled
with dense and warm gas, contains a dynamical mass of (4-5)x10^9M_sun, a
luminosity of L'_HCN=(3-4)x10^8 K km/s pc^2, and a dust temperature of 55 K. At
the very centre, a compact core with R~50 pc has a luminosity of
L_IR=4x10^11L_sun (30% of the total infrared luminosity), and a dust
temperature of 95 K. The core is expanding at low velocities ~50-100 km/s,
probably affected by the outflowing gas. We detect the blue-shifted component
of the outflow, while the red-shifted counterpart remains undetected in our
data. Its cold and dense phase reaches fast velocities up to ~1000 km/s, while
the warm outflowing gas has more moderate maximum velocities of ~600 km/s. The
outflow is detected as far as 460 pc from the centre in the northern direction,
and has a mass of dense gas <8x10^8M_sun. The difference between the position
angles of the inner disk (~70 degree) and the outflow (~10 degree) indicates
that the outflow is likely powered by the AGN, and not by the starburst.
Regarding the chemistry, we measure an extremely low HCO+/HOC+ ratio of 10+-5
in the inner disk of Mrk273.Comment: Accepted for publication in A&A. 21 pages, 17 figures, 7 tables, and
a lot of interesting tex
VO2 indirect maximum and fitness age of sedentary and non-sedentary
El objetivo es: comparar la edad cronológica con la edad fitness obtenida
por medio del VO2 máximo indirecto, de un grupo de personas sedentarias y no
sedentarias. Método: 253 personas fueron evaluadas respecto a masa corporal,
estatura, perímetro de cintura, frecuencia cardiaca basal y un cuestionario del
modelo web "Fitness Calculator". Los resultados demostraron diferencias
significativas en las variables antropométricas y fisiológicas entre personas
sedentarias y no sedentarias (P<,001). Las personas no sedentarias tienen un
mayor VO2máx en comparación con las personas sedentarias. Las personas
sedentarias indican que presentan una edad fitness que se encuentra sobre 12
años cronológicos promedio de lo esperado. Conclusión: Las personas
sedentarias tienen una mayor edad fitness, esto permite establecer que su
cuerpo se deteriora más rápido que los no sedentarios. El bajo VO2 máx es un
potente predictor de la capacidad cardiorrespiratoria y se establece como un
predictor de enfermedades cardiovascularesThe purpose was to compare chronological age with fitness age obtained
through indirect VO2max in a group of sedentary and non-sedentary people.
Method: 253 people were evaluated for body mass, height, waist circumference,
basal heart rate and a web model questionnaire "Fitness Calculator". The
results: showed significant differences in anthropometric and physiological
variables between sedentary and non-sedentary people (P <.001). Non-
Sedentary people have a greater higher VO2máx group compared to sedentary
people. This indicates that sedentary people have a fitness age 12 years over
their expected chronological average age. Conclusion: Sedentary people have
a higher fitness age; therefore your body deteriorates faster than the nonsedentary
people. A low level of VO2máx is a powerful predictor of
cardiorespiratory capacity and of cardiovascular diseasesEl estudio fue financiado por la Escuela de Kinesiología de la Universidad Bernardo O`higgin
Evidence for a chemically differentiated outflow in Mrk 231
Aims: Our goal is to study the chemical composition of the outflows of active
galactic nuclei and starburst galaxies.
Methods: We obtained high-resolution interferometric observations of HCN and
HCO and of the ultraluminous infrared
galaxy Mrk~231 with the IRAM Plateau de Bure Interferometer. We also use
previously published observations of HCN and HCO and
, and HNC in the same source.
Results: In the line wings of the HCN, HCO, and HNC emission, we find
that these three molecular species exhibit features at distinct velocities
which differ between the species. The features are not consistent with emission
lines of other molecular species. Through radiative transfer modelling of the
HCN and HCO outflow emission we find an average abundance ratio
. Assuming a clumpy outflow,
modelling of the HCN and HCO emission produces strongly inconsistent
outflow masses.
Conclusions: Both the anti-correlated outflow features of HCN and HCO and
the different outflow masses calculated from the radiative transfer models of
the HCN and HCO emission suggest that the outflow is chemically
differentiated. The separation between HCN and HCO could be an indicator of
shock fronts present in the outflow, since the HCN/HCO ratio is expected to
be elevated in shocked regions. Our result shows that studies of the chemistry
in large-scale galactic outflows can be used to better understand the physical
properties of these outflows and their effects on the interstellar medium (ISM)
in the galaxy.Comment: 12 pages, 8 figures, accepted for publication in A&
ALMA resolves the torus of NGC 1068: continuum and molecular line emission
We have used the Atacama Large Millimeter Array (ALMA) to map the emission of
the CO(6-5) molecular line and the 432 {\mu}m continuum emission from the 300
pc-sized circumnuclear disk (CND) of the nearby Seyfert 2 galaxy NGC 1068 with
a spatial resolution of ~4 pc. These observations spatially resolve the CND
and, for the first time, image the dust emission, the molecular gas
distribution, and the kinematics from a 7-10 pc-diameter disk that represents
the submillimeter counterpart of the putative torus of NGC 1068. We fitted the
nuclear spectral energy distribution of the torus using ALMA and near and
mid-infrared (NIR/MIR) data with CLUMPY models. The mass and radius of the
best-fit solution for the torus are both consistent with the values derived
from the ALMA data alone: Mgas_torus=(1+-0.3)x10^5 Msun and Rtorus=3.5+-0.5 pc.
The dynamics of the molecular gas in the torus show non-circular motions and
enhanced turbulence superposed on the rotating pattern of the disk. The
kinematic major axis of the CO torus is tilted relative to its morphological
major axis. By contrast with the nearly edge-on orientation of the H2O
megamaser disk, we have found evidence suggesting that the molecular torus is
less inclined (i=34deg-66deg) at larger radii. The lopsided morphology and
complex kinematics of the torus could be the signature of the
Papaloizou-Pringle instability, long predicted to likely drive the dynamical
evolution of active galactic nuclei (AGN) tori.Comment: Final version accepted by the Astrophysical Journal Letters
(ApJLetters) on April 27th 2016, 6 pages, 5 figure
Potential role of orexin A binding the receptor 1 for orexins in normal and cryptorchid dogs.
Background: Cryptorchidism is one of the most common birth disorders of the male reproductive system identified in
dogs and other mammals. This condition is characterised by the absence of one (unilateral) or both (bilateral) gonads
from the scrotum. The peptides orexin A (OxA) and B (OxB) were obtained by post-transcriptional proteolytic cleavage
of a precursor molecule, called prepro-orexin. These substances bind two types of G-coupled receptors called receptor
1 (OX1R) and 2 (OX2R) for orexins. OX1R is specific to OxA while OX2R binds the two peptides with equal affinity.
Orexins modulate a great variety of body functions, such as the reproductive mechanism. The purpose of the present
research was to study the presence of OxA and its receptor 1 and their possible involvement in the canine testis under
healthy and pathological conditions.
Methods: This study was performed using adult male normal dogs and male dogs affected by unilateral cryptorchidism.
Tissue samples were collected from testes and were divided into three groups: normal, contralateral and cryptic. The
samples were used for immunohistochemistry, Western blot and in vitro tests for testosterone evaluation in normal and
pathological conditions.
Results: OxA-immunoreactivity (IR) was described in interstitial Leydig cells of the normal gonad, and Leydig, Sertoli cells
and gonocytes in the cryptic gonad. In the normal testis, OX1R-IR was described in Leydig cells, in pachytene and
second spermatocytes and in immature and mature spermatids throughout the stages of the germ developing
cycle of the male gonad. In the cryptic testis OX1R-IR was distributed in Leydig and Sertoli cells. The presence of
prepro-orexin and OX1R was demonstrated by Western blot analysis. The incubation of fresh testis slices with
OxA caused the stimulation of testosterone synthesis in the normal and cryptic gonad while the steroidogenic
OxA-induced effect was cancelled by adding the selective OX1R antagonist SB-408124.
Conclusions: These results led us to hypothesise that OxA binding OX1R might be involved in the modulation of
spermatogenesis and steroidogenesis in canine testis in healthy and pathological conditions
Molecular line emission in NGC1068 imaged with ALMA. I An AGN-driven outflow in the dense molecular gas
We investigate the fueling and the feedback of star formation and nuclear
activity in NGC1068, a nearby (D=14Mpc) Seyfert 2 barred galaxy, by analyzing
the distribution and kinematics of the molecular gas in the disk. We have used
ALMA to map the emission of a set of dense molecular gas tracers (CO(3-2),
CO(6-5), HCN(4-3), HCO+(4-3) and CS(7-6)) and their underlying continuum
emission in the central r ~ 2kpc of NGC1068 with spatial resolutions ~
0.3"-0.5" (~ 20-35pc). Molecular line and dust continuum emissions are detected
from a r ~ 200pc off-centered circumnuclear disk (CND), from the
2.6kpc-diameter bar region, and from the r ~ 1.3kpc starburst (SB) ring. Most
of the emission in HCO+, HCN and CS stems from the CND. Molecular line ratios
show dramatic order-of-magnitude changes inside the CND that are correlated
with the UV/X-ray illumination by the AGN, betraying ongoing feedback. The gas
kinematics from r ~ 50pc out to r ~ 400pc reveal a massive (M_mol ~ 2.7 (+0.9,
-1.2) x 10^7 Msun) outflow in all molecular tracers. The tight correlation
between the ionized gas outflow, the radio jet and the occurrence of outward
motions in the disk suggests that the outflow is AGN-driven. The outflow rate
estimated in the CND, dM/dt ~ 63 (+21, -37) Msun yr^-1, is an order of
magnitude higher than the star formation rate at these radii, confirming that
the outflow is AGN-driven. The power of the AGN is able to account for the
estimated momentum and kinetic luminosity of the outflow. The CND mass load
rate of the CND outflow implies a very short gas depletion time scale of <=1
Myr.Comment: Version accepted for publication in A&A (June 4th). Accepted version.
References (3) added and minor typos corrected. 24 pages, 20 figure
Molecular line emission in NGC1068 imaged with ALMA: II. The chemistry of the dense molecular gas
We present a detailed analysis of ALMA Bands 7 and 9 data of CO, HCO+, HCN
and CS, augmented with Plateau de Bure Interferometer (PdBI) data of the ~ 200
pc circumnuclear disk (CND) and the ~ 1.3 kpc starburst ring (SB ring) of
NGC~1068, a nearby (D = 14 Mpc) Seyfert 2 barred galaxy. We aim at determining
the physical characteristics of the dense gas present in the CND and whether
the different line intensity ratios we find within the CND as well as between
the CND and the SB ring are due to excitation effects (gas density and
temperature differences) or to a different chemistry. We estimate the column
densities of each species in Local Thermodynamic Equilibrium (LTE). We then
compute large one-dimensional non-LTE radiative transfer grids (using RADEX) by
using first only the CO transitions, and then all the available molecules in
order to constrain the densities, temperatures and column densities within the
CND. We finally present a preliminary set of chemical models to determine the
origin of the gas. We find that in general the gas in the CND is very dense (>
10^5 cm^-3) and hot (T> 150K), with differences especially in the temperature
across the CND. The AGN position has the lowest CO/HCO+, CO/HCN and CO/CS
column density ratios. RADEX analyses seem to indicate that there is chemical
differentiation across the CND. We also find differences between the chemistry
of the SB ring and some regions of the CND; the SB ring is also much colder and
less dense than the CND. Chemical modelling does not succeed in reproducing all
the molecular ratios with one model per region, suggesting the presence of
multi-gas phase components. The LTE, RADEX and chemical analyses all indicate
that more than one gas-phase component is necessary to uniquely fit all the
available molecular ratios within the CND.Comment: Accepted by A&A; please contact the author for a better version of
the pdf where the resolution and positions of figures are as they will appear
in the Journa
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