3,816 research outputs found
Identification and expression pattern of a new carotenoid cleavage dioxygenase gene member from Bixa orellana
Carotenoid cleavage dioxygenases (CCDs) are a class of enzymes involved in the biosynthesis of a broad diversity of secondary metabolites known as apocarotenoids. In plants, CCDs are part of a genetic family with members which cleave specific double bonds of carotenoid molecules. CCDs are involved in the production of diverse and important metabolites such as vitamin A and abscisic acid (ABA). Bixa orellana L. is the main source of the natural pigment annatto or bixin, an apocarotenoid accumulated in large quantities in its seeds. Bixin biosynthesis has been studied and the involvement of a CCD has been confirmed in vitro. However, the CCD genes involved in the biosynthesis of the wide variety of apocarotenoids found in this plant have not been well documented. In this study, a new CCD1 gene member (BoCCD1) was identified and its expression was charaterized in different plant tissues of B. orellana plantlets and adult plants. The BoCCD1 sequence showed high homology with plant CCD1s involved mainly in the cleavage of carotenoids in several sites to generate multiple apocarotenoid products. Here, the expression profiles of the BoCCD1 gene were analysed and discussed in relation to total carotenoids and other important apocarotenoids such as bixin
The Detection and Characterization of cm Radio Continuum Emission from the Low-mass Protostar L1014-IRS
Observations by the Cores to Disk Legacy Team with the Spitzer Space
Telescope have identified a low luminosity, mid-infrared source within the
dense core, Lynds 1014, which was previously thought to harbor no internal
source. Followup near-infrared and submillimeter interferometric observations
have confirmed the protostellar nature of this source by detecting scattered
light from an outflow cavity and a weak molecular outflow. In this paper, we
report the detection of cm continuum emission with the VLA. The emission is
characterized by a quiescent, unresolved 90 uJy 6 cm source within 0.2" of the
Spitzer source. The spectral index of the quiescent component is between 6 cm and 3.6 cm. A factor of two increase in 6 cm
emission was detected during one epoch and circular polarization was marginally
detected at the level with Stokes {V/I} % . We have
searched for 22 GHz H2O maser emission toward L1014-IRS, but no masers were
detected during 7 epochs of observations between June 2004 and December 2006.
L1014-IRS appears to be a low-mass, accreting protostar which exhibits cm
emission from a thermal jet or a wind, with a variable non-thermal emission
component. The quiescent cm radio emission is noticeably above the correlation
of 3.6 cm and 6 cm luminosity versus bolometric luminosity, indicating more
radio emission than expected. We characterize the cm continuum emission in
terms of observations of other low-mass protostars, including updated
correlations of centimeter continuum emission with bolometric luminosity and
outflow force, and discuss the implications of recent larger distance estimates
on the physical attributes of the protostar and dense molecular core.Comment: 14 pages. Accepted for publication in Ap
Occurrence of priority pollutants in WWTP effluents and Mediterranean coastal waters of Spain
A comprehensive study aimed at evaluating the occurrence, significance of concentrations and spatial distribution of priority pollutants (PPs) along the Comunidad Valenciana coastal waters (Spain) was carried out in order to fulfil the European Water Framework Directive (WFD). Additionally, PP concentrations were also analysed in the effluent of 28 WWTPs distributed along the studied area. In coastal waters 36 organic pollutants of the 71 analysed, including 26 PPs were detected although many of them with low frequency of occurrence. Only 13 compounds, which belong to four different classes (VOCs, organochlorinated pesticides, phthalates and tributyltin compounds (TBT)) showed a frequency of occurrence above 20% in coastal waters. In the results obtained until now, octylphenol, pentachlorobenzene, DEHP and TBT exceeded the annual average concentration (EQS-AAC), and only TBT surpassed the maximum allowable concentration (EQS-MAC). The most frequent contaminants determined in coastal waters were also present in WWTP effluents. (C) 2011 Elsevier Ltd. All rights reserved.Financial support from Conselleria de Medio Ambiente, Agua, Urbanismo y Vivienda de la Generalitat Valenciana (Application of Water Framework Directive 2000/60/EC on endocrine disruptors and priority substances in coastal areas in the Comunidad Valenciana) is gratefully acknowledged.MartĂ Ortega, N.; Aguado GarcĂa, D.; Segovia MartĂnez, L.; Bouzas Blanco, A.; Seco Torrecillas, A. (2011). Occurrence of priority pollutants in WWTP effluents and Mediterranean coastal waters of Spain. Marine Pollution Bulletin. 62(3):615-625. doi:10.1016/j.marpolbul.2011.01.010S61562562
Asteroseismology of the Beta Cephei star Nu Eridani: photometric observations and pulsational frequency analysis
We undertook a multisite photometric campaign for the Beta Cephei star Nu
Eridani. More than 600 hours of differential photoelectric uvyV photometry were
obtained with 11 telescopes during 148 clear nights. The frequency analysis of
our measurements shows that the variability of Nu Eri can be decomposed into 23
sinusoidal components, eight of which correspond to independent pulsation
frequencies between 5 - 8 c/d. Some of these are arranged in multiplets, which
suggests rotational m-mode splitting of nonradial pulsation modes as the cause.
If so, the rotation period of the star must be between 30 - 60 d. One of the
signals in the light curves of Nu Eri has a very low frequency of 0.432 c/d. It
can be a high-order combination frequency or, more likely, an independent
pulsation mode. In the latter case Nu Eri would be both a Beta Cephei star and
a slowly pulsating B (SPB) star. The photometric amplitudes of the individual
pulsation modes of Nu Eri appear to have increased by about 20 per cent over
the last 40 years. So do the amplitudes of the dominant combination frequencies
of the star. Among the latter, we only could identify sum frequencies with
certainty, not difference frequencies, which suggests that neither light-curve
distortion in its simplest form nor resonant mode coupling are their single
cause. One of our comparison stars, Mu Eridani, turned out to be variable with
a dominant time scale of 1.62 d. We believe that it is either an SPB star just
leaving its instability strip or that its variations are of rotational origin.Comment: 10 pages, 5 figure
First wave of COVID-19 in Venezuela:Epidemiological, clinical, and paraclinical characteristics of first cases
The coronavirus disease 2019 (COVID-19) pandemic has particularly affected countries with weakened health services in Latin America, where proper patient management could be a critical step to address the epidemic. In this study, we aimed to characterize and identify which epidemiological, clinical, and paraclinical risk factors defined COVID-19 infection from the first confirmed cases through the first epidemic wave in Venezuela. A retrospective analysis of consecutive suspected cases of COVID-19 admitted to a sentinel hospital was carried out, including 576 patient cases subsequently confirmed for severe acute respiratory syndrome coronavirus 2 infection. Of these, 162 (28.1%) patients met the definition criteria for severe/critical disease, and 414 (71.2%) were classified as mild/moderate disease. The mean age was 47 (SD 16) years, the majority of which were men (59.5%), and the most frequent comorbidity was arterial hypertension (23.3%). The most common symptoms included fever (88.7%), headache (65.6%), and dry cough (63.9%). Severe/critical disease affected mostly older males with low schooling (p < 0.001). Similarly, higher levels of glycemia, urea, aminotransferases, total bilirubin, lactate dehydrogenase, and erythrocyte sedimentation rate were observed in severe/critical disease patients compared to those with mild/moderate disease. Overall mortality was 7.6% (44/576), with 41.7% (28/68) dying in hospital. We identified risk factors related to COVID-19 infection, which could help healthcare providers take appropriate measures and prevent severe clinical outcomes. Our results suggest that the mortality registered by this disease in Venezuela during the first epidemic wave was underestimated. An increase in fatalities is expected to occur in the coming months unless measures that are more effective are implemented to mitigate the epidemic while the vaccination process is ongoing
Rethinking Research Ethics for Latinos: The Policy Paradox of Health Reform and the Role of Social Justice
http://dx.doi.org/10.1080/10508422.2012.72999
Highlights from the Pierre Auger Observatory
The Pierre Auger Observatory is the world's largest cosmic ray observatory.
Our current exposure reaches nearly 40,000 km str and provides us with an
unprecedented quality data set. The performance and stability of the detectors
and their enhancements are described. Data analyses have led to a number of
major breakthroughs. Among these we discuss the energy spectrum and the
searches for large-scale anisotropies. We present analyses of our X
data and show how it can be interpreted in terms of mass composition. We also
describe some new analyses that extract mass sensitive parameters from the 100%
duty cycle SD data. A coherent interpretation of all these recent results opens
new directions. The consequences regarding the cosmic ray composition and the
properties of UHECR sources are briefly discussed.Comment: 9 pages, 12 figures, talk given at the 33rd International Cosmic Ray
Conference, Rio de Janeiro 201
A search for point sources of EeV photons
Measurements of air showers made using the hybrid technique developed with
the fluorescence and surface detectors of the Pierre Auger Observatory allow a
sensitive search for point sources of EeV photons anywhere in the exposed sky.
A multivariate analysis reduces the background of hadronic cosmic rays. The
search is sensitive to a declination band from -85{\deg} to +20{\deg}, in an
energy range from 10^17.3 eV to 10^18.5 eV. No photon point source has been
detected. An upper limit on the photon flux has been derived for every
direction. The mean value of the energy flux limit that results from this,
assuming a photon spectral index of -2, is 0.06 eV cm^-2 s^-1, and no celestial
direction exceeds 0.25 eV cm^-2 s^-1. These upper limits constrain scenarios in
which EeV cosmic ray protons are emitted by non-transient sources in the
Galaxy.Comment: 28 pages, 10 figures, accepted for publication in The Astrophysical
Journa
The Pierre Auger Observatory III: Other Astrophysical Observations
Astrophysical observations of ultra-high-energy cosmic rays with the Pierre
Auger ObservatoryComment: Contributions to the 32nd International Cosmic Ray Conference,
Beijing, China, August 201
Reconstruction of inclined air showers detected with the Pierre Auger Observatory
We describe the method devised to reconstruct inclined cosmic-ray air showers
with zenith angles greater than detected with the surface array of
the Pierre Auger Observatory. The measured signals at the ground level are
fitted to muon density distributions predicted with atmospheric cascade models
to obtain the relative shower size as an overall normalization parameter. The
method is evaluated using simulated showers to test its performance. The energy
of the cosmic rays is calibrated using a sub-sample of events reconstructed
with both the fluorescence and surface array techniques. The reconstruction
method described here provides the basis of complementary analyses including an
independent measurement of the energy spectrum of ultra-high energy cosmic rays
using very inclined events collected by the Pierre Auger Observatory.Comment: 27 pages, 19 figures, accepted for publication in Journal of
Cosmology and Astroparticle Physics (JCAP
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