81 research outputs found
Characterizing a Mini Gamma Detector
There are several types of gamma radiation detectors, which have different characteristics depending on its use. We designed and instrumented a gamma detector for low energies of a small and portable size to obtain spectrum from radioactive sources and from that analyze each spectrum. This instrument basically consists of a scintillator crystal coupled to a SiPM this in turn coupled to a PCB card designed with capacitors and resistors for a better signal, a voltage source of 29 volts. For signal acquisition the system must be connected to an oscilloscope this in turn is controlled by a script developed in Python. For the calibration radioactive isotopes with the same dimensions were used, caesium-137 (Cs-137), cobalto-60 (Co-60), sodium-22 (Na-22) and manganese-54 (Mn-54) as gamma ray emission
Role of Na+ transporters HKT1;1 and HKT1;2 in tomato salt tolerance. I. Function loss of cheesmaniae alleles in roots and aerial parts
We wish to thank Elena Sanchez Romero (EEZ-CSIC) for her technical assistance, the Scientific Instrumentation Service at EEZ-CSIC, Granada, for their ICP-OES mineral analysis and Michael O'Shea for proofreading the manuscript. The study was funded by grant AGL201782452-C2-1R (A.B.) and grant AGL2017-82452-C2-2R (M.J.A.), both from the Spanish Ministerio de Ciencia e Innovacion/Agencia Estatal de Investigacion, MCIN/AEI/10.13039/501100011033, and FEDER "Una manera de hacer Europa", as well as grant ACCESP2018 (J.A.T.) from the University of Granada. J.E. was supported by a JAE Intro-CSIC grant, JAEINT_19_00566.We analyzed the physiological impact of function loss on cheesmaniae alleles at the HKT1;1 and HKT1;2 loci in
the roots and aerial parts of tomato plants in order to determine the relative contributions of each locus in the
different tissues to plant Na+/K+ homeostasis and subsequently to tomato salt tolerance. We generated different
reciprocal rootstock/scion combinations with non-silenced, single RNAi-silenced lines for ScHKT1;1 and
ScHKT1;2, as well as a silenced line at both loci from a near isogenic line (NIL14), homozygous for the Solanum
cheesmaniae haplotype containing both HKT1 loci and subjected to salinity under natural greenhouse conditions.
Our results show that salt treatment reduced vegetative growth and altered the Na+/K+ ratio in leaves and
flowers; negatively affecting fruit production, particularly in graft combinations containing single silenced
ScHKT1;2- and double silenced ScHKT1;1/ScHKT1;2 lines when used as scion. We concluded that the removal of
Na+ from the xylem by ScHKT1;2 in the aerial part of the plant can have an even greater impact than that on Na+
homeostasis at the root level under saline conditions. Also, ScHKT1;1 function loss in rootstock greatly reduced
the Na+/K+ ratio in leaf and flower tissues, minimized yield loss under salinity. Our results suggest that, in
addition to xylem Na+ unloading, ScHKT1;2 could also be involved in Na+ uploading into the phloem, thus
promoting Na+ recirculation from aerial parts to the roots. This recirculation of Na+ to the roots through the
phloem could be further favoured by ScHKT1;1 silencing at these roots.Spanish Ministerio de Ciencia e Innovacion/Agencia Estatal de Investigacion AGL2017-82452-C2-1R
AGL2017-82452-C2-2RFEDER "Una manera de hacer Europa" MCIN/AEI/10.13039/501100011033University of Granada ACCESP2018JAE Intro-CSIC grant JAEINT_19_0056
Charge-Reversal Instability in Mixed Bilayer Vesicles
Bilayer vesicles form readily from mixtures of charged and neutral
surfactants. When such a mixed vesicle binds an oppositely-charged object, its
membrane partially demixes: the adhesion zone recruits more charged surfactants
from the rest of the membrane. Given an unlimited supply of adhering objects
one might expect the vesicle to remain attractive until it was completely
covered. Contrary to this expectation, we show that a vesicle can instead
exhibit {\it adhesion saturation,} partitioning spontaneously into an
attractive zone with definite area fraction, and a repulsive zone. The latter
zone rejects additional incoming objects because counterions on the interior of
the vesicle migrate there, effectively reversing the membrane's charge. The
effect is strongest at high surface charge densities, low ionic strength, and
with thin, impermeable membranes. Adhesion saturation in such a situation has
recently been observed experimentally [H. Aranda-Espinoza {\it et al.}, {\sl
Science} {\bf285} 394--397 (1999)]
Stellar Populations in type Ia supernova host galaxies at intermediate-high redshift: Star formation and metallicity enrichment histories
We present a summary of our project that studies galaxies hosting type Ia
supernova (SN Ia) at different redshifts. We present Gran Telescopio de
Canarias (GTC) optical spectroscopy of six SN Ia host galaxies at redshift
. They are joined to a set of SN Ia host galaxies at
intermediate-high redshift, which include galaxies from surveys SDSS and
COSMOS. The final sample, after a selection of galaxy spectra in terms of
signal-to-noise and other characteristics, consists of 680 galaxies with
redshift in the range . We perform an inverse stellar population
synthesis with the code {\sc fado} to estimate the star formation and
enrichment histories of this set of galaxies, simultaneously obtaining their
mean stellar age and metallicity and stellar mass. After analysing the
correlations among these characteristics, we look for possible dependencies of
the Hubble diagram residuals and supernova features (luminosity, color and
strength parameter) on these stellar parameters. We find that the Hubble
residuals show a clear dependence on the stellar metallicity weighted by mass
with a slope of -0.061\,mag\,dex, when represented in logarithmic scale,
. This result supports our previous
findings obtained from gas oxygen abundances for local and SDSS-survey
galaxies. Comparing with other works from the literature that also use the
stellar metallicity, we find a similar value, but with more precision and a
better significance (2.08 vs 1.1), due to the higher number of objects
and wider range of redshift of our sample.Comment: 21 pages, 19 figures, accepted for publication in Monthly Notices of
the Royal Astronomical Societ
pyFIT3D and pyPipe3D -- The new version of the Integral Field Spectroscopy data analysis pipeline
We present a new version of the FIT3D and Pipe3D codes, two packages to
derive properties of the stellar populations and the ionized emission lines
from optical spectroscopy and integral field spectroscopy data respectively.
The new codes have been fully transcribed to Python from the original Perl and
C versions, modifying the algorithms when needed to make use of the unique
capabilities of this language with the main goals of (1) respecting as much as
possible the original philosophy of the algorithms, (2) maintaining a full
compatibility with the original version in terms of the format of the required
input and produced output files, and (3) improving the efficiency and accuracy
of the algorithms, and solving known (and newly discovered) bugs. The complete
package is freely distributed, with an available repository online. pyFIT3D and
pyPipe3D are fully tested with data of the most recent IFS data surveys and
compilations (e.g. CALIFA, MaNGA, SAMI and AMUSING++), and confronted with
simulations. We describe here the code, its new implementation, its accuracy in
recovering the parameters based on simulations, and a showcase of its
implementation on a particular dataset.Comment: New Astronomy - 29 pages, 19 figures - Received on 7 Dec 2021 -
Accepted for publication on 8 Jul 202
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