5,013 research outputs found
Adaptation Strategies and Microwave Drying of Amaranth Species with a High Nutritional Value to the Ecuadorian Andean Region
In the Andean region of Ecuador, amaranth is a key species not only for its high nutritional value but also for its association with Ecuadorian culture, since it is one of the main indigenous crops of the pre-Columbian era. Over the time, the cultivation of this species ceased for several reasons result. However, in recent years, a number of strategies have been developed to retrieve it on a national level. In accordance with these strategies, the “Amaranth Improvement Program for Cotopaxi” (PROMAC) is being developed at the Technical University of Cotopaxi, with the main objective of selecting varieties with high levels of biologically active substances. This program is been executed through two main lines of investigation: (a) selection of varieties of amaranth of high nutritional value and (b) the improvement of techniques for conservation of the seeds. This chapter analyzes and shows the main results obtained to date from the study of eight varieties of amaranth seeds and the drying of one of the seeds by means of microwave energy in order to improve its conservation. In the light of the results obtained, the strategies to develop the following research lines within the PROMAC framework are exposed
Porous Titanium surfaces to control bacteria growth: mechanical properties and sulfonated polyetheretherketone coating as antibiofounling approaches
Here, titanium porous substrates were fabricated by a space holder technique. The relationship between microstructural characteristics (pore equivalent diameter, mean free-path between pores, roughness and contact surface), mechanical properties (Young’s modulus, yield strength and dynamic micro-hardness) and bacterial behavior are discussed. The bacterial strains evaluated are often found on dental implants: Methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa. The colony-forming units increased with the size of the spacer for both types of studied strains. An antibiofouling synthetic coating based on a sulfonated polyetheretherketone polymer revealed an effective chemical surface modification for inhibiting MRSA adhesion and growth. These findings collectively suggest that porous titanium implants designed with a pore size of 100–200 µm can be considered most suitable, assuring the best biomechanical and bifunctional anti-bacterial properties.University of Seville VI Plan Propio de Investigación y Transferencia—US 2018, I.3A
Anomalous Hall conductivity control in MnNiN antiperovskite by epitaxial strain along the kagome plane
Antiferromagnetic manganese-based nitride antiperovskites, such as MnNiN,
hold a triangular frustrated magnetic ordering over their kagome lattice formed
by the Mn atoms along the (111)-plane. As such, frustration imposes a
non-trivial interplay between the symmetric and asymmetric magnetic
interactions, which can only reach equilibrium in a noncollinear magnetic
configuration. Consequently, the associated electronic interactions and their
possible tuning by external constraints, such as applied epitaxial strain, play
a crucial role in defining the microscopic and macroscopic properties of such
topological condensed matter systems. Thus, in the present work, we explored
and explained the effect of the epitaxial strain imposed within the
(111)-plane, in which the magnetic and crystallographic symmetry operations are
kept fixed, and only the magnitude of the ionic and electronic interactions are
tuned. We found a linear shifting in the energy of the band structure and a
linear increase/decrease of the available states near the Fermi level with the
applied strain. Concretely, the compression strain reduces the Mn-Mn distances
in the (111) kagome plane but linearly increases the separation between the
stacked kagome lattices and the available states near the Fermi level. Despite
the linear controlling of the available states across the Fermi energy, the
anomalous Hall conductivity shows a non-linear behavior where the
conductivity nearly vanishes for tensile strain. On the other
hand, fetches a maximum increase of 26\% about the unstrained
structure for a compression value close to 1.5\%.This behavior found an
explanation in the non-divergent Berry curvature within the kagome plane, which
is increased for constraining but significantly reduced for expansion strain
values..
Endoplasmic Reticulum Stress during Mammalian Follicular Atresia
Follicles are ovarian structures that contain a single germ cell. During the mammalian reproductive lifetime, ovarian follicles mature through the process of follicular development, with the aim of selecting oocytes for ovulation. As part of this process, several follicles are eliminated by means of follicular atresia, a mechanism that mainly involves apoptosis. Nevertheless, it has been shown that there are other routes of programmed cell death in the ovary including autophagy, paraptosis, and necroptosis. Surprisingly, the endoplasmic reticulum is involved in these different programmed cell death pathways. Moreover, there are several evidences for the pathways triggered by intra- and extracellular signals in endoplasmic reticulum-induced cell death. Thus, it is important to analyze the participation of endoplasmic reticulum in follicular atresia
Pre-main sequence stars in the Lagoon Nebula (M8)
We report the discovery of new pre-main sequence (PMS) stars in the Lagoon
Nebula (M8) at a distance of 1.25 kpc, based on intermediate resolution spectra
obtained with the Boller & Chivens spectrograph at the 6.5-m Magellan I
telescope (Las Campanas Observatory, Chile). According to the spectral types,
the presence of emission lines and the lithium 6708A absorption line, we are
able to identify 27 classical T Tauri stars, 7 weak-lined T Tauri stars and 3
PMS emission objects with spectral type G, which we include in a separated
stellar class denominated "PMS Fe/Ge class". Using near-infrared photometry
either from 2MASS or from our own previous work we derive effective
temperatures and luminosities for these stars and locate them in the
Hertzsprung-Russell diagram, in order to estimate their masses and ages. We
find that almost all of our sample stars are younger than 3 10^6 years and span
over a range of masses between 0.8 and 2.5 Msun. A cross-correlation between
our spectroscopic data and the X-ray sources detected with the Chandra ACIS
instrument is also presented.Comment: 18 pages, 15 figures, MNRAS, in pres
Sparse spectral-tau method for the three-dimensional helically reduced wave equation on two-center domains
We describe a multidomain spectral-tau method for solving the
three-dimensional helically reduced wave equation on the type of two-center
domain that arises when modeling compact binary objects in astrophysical
applications. A global two-center domain may arise as the union of Cartesian
blocks, cylindrical shells, and inner and outer spherical shells. For each such
subdomain, our key objective is to realize certain (differential and
multiplication) physical-space operators as matrices acting on the
corresponding set of modal coefficients. We achieve sparse banded realizations
through the integration "preconditioning" of Coutsias, Hagstrom, Hesthaven, and
Torres. Since ours is the first three-dimensional multidomain implementation of
the technique, we focus on the issue of convergence for the global solver, here
the alternating Schwarz method accelerated by GMRES. Our methods may prove
relevant for numerical solution of other mixed-type or elliptic problems, and
in particular for the generation of initial data in general relativity.Comment: 37 pages, 3 figures, 12 table
Trigger efficiencies of a proposed beam monitoring detector (BeBe) for p+p collisions at NICA energies
The Multipurpose Detector (MPD) consists of a typical array of sub-detectors
to study the nuclear matter originating from the collisions of beams provided
by the Nuclotron-based Ion Collider fAcility (NICA). A beam monitoring
detector~(BeBe) is proposed for stage 2 of MPD to increase the trigger
capabilities. BeBe is constituted of two plastic scintillator disks segmented
in 80 cells away from the interaction point of MPD. Laboratory
measurements to obtain the energy resolution of an individual BeBe cell
prototype are presented. It is shown that an energy resolution of
can be obtained. Based on Monte Carlo simulations, the trigger efficiencies of
the BeBe are presented for p+p collisions at 11~GeV considering a threshold in
the energy loss of the charged particles reaching the detector
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