205 research outputs found
Analysis of genetic markers in a sample of uruguayan criollo horses
The aim of this work is to charaterize at least tentatively the Criollo Horses of Uruguay through blood genetic markers. This breed, whose origin goes back to horses brought to Rio de la Plata in 1538 from Spain, nowadays, after more than four centuries in its environment, owns unique zootechnical traits and well developed rusticity. We have studied 7 systems of blood groups (A, C, D, K, P, Q and U) and 6 of biochemical polymorphisms (A1B, Al, Tf, alk-Es, PGD, PGM) in a sample of 99 Criollo Horses of Uruguay. The most polymorphic loci were the D blood group system with 13 alleles, Ddelo, Dadl and Ddkl being the 3 most frequent ones, and the Tf locus, that displayed 7 alleles, D and F2 having the highest frequency. The genetic variability of the sample was estimated through the average heterozigosity that reached a value of 0.435. Concerning the origin of the breed, we have to stress the presence in our sample of TfJ and Dcfgk, breed allele markers of the Spanish Pure Breed Horse. We conclude from these results that the present days Criollo Horses of Uruguay have preserved some blood genetic traits of its ancestors that differentiate them from the other Criollo Horses, displaying at the same time an important amount of genetic variability as shown by the high value of average heterozigosity.En esta comunicación preliminar, presentamos la evaluación de las frecuencias alélicas obtenidas en 7 sistemas de grupos sanguíneos (A, C, D, K, P, Q y U) y 6 polimorfismos bioquímicos (A1B, Al, Es alcalina, Tf, PGD y PGM) en una muestra de 99 Caballos Criollos del Uruguay (CCU). Los sistemas más polimórficos fueron el sistema D, con 13 alelos siendo los más frecuentes: Ddelo, Dadl y Ddkl, y el locus Tf con 7 alelos siendo los más frecuentes: D y F2. Todos los sistemas electroforéticos se encontraron en equilibrio génico. La variabilidad genética de la muestra estudiada se estimó mediante el Índice de Heterocigosidad esperada, el cual presentó un valor de 0,435. En la muestra analizada se destaca la presencia de la variante TfJ y del alelo Dcfgk, marcadores característicos de la Pura Raza Española (PRE). Se puede concluir que estos datos proporcionan información de que los Caballos Criollos Uruguayos conservan parte del potencial genético de sus ancestros, manteniendo características propias y diferentes a la de las otros Caballos Criollos. En cuanto a la variabilidad genética, a pesar de ser una muestra pequeña, presentó un índice de heterocigosidad bastante alto
Metabolic Fingerprint of Acromegaly and its Potential Usefulness in Clinical Practice
Insulin-like growth factor-1 (IGF-1) and growth hormone (GH) levels are the main targets for monitoring acromegaly activity, but they are not in close relationship with the clinical course of the disease and the associated comorbidities. The present study was aimed at identifying metabolites that could be used as biomarkers for a better disease phenotyping. For this purpose, metabolic fingerprint using an untargeted metabolomic approach was examined in serum from 30 patients with acromegaly and 30 age-matched controls. Patients with acromegaly presented fewer branched-chain amino acids (BCAAs) compared to the control group (valine: 4.75 ± 0.87 vs. 5.20 ± 1.06 arbitrary units (AUs), p < 0.05; isoleucine: 2.54 ± 0.41 vs. 2.80 ± 0.51 AUs; p < 0.05). BCAAs were also lower in patients with active disease compared to patients with normal levels of IGF-1 with or without medical treatment. GH, but not IGF-1, serum levels were inversely correlated with both valine and isoleucine. These findings indicate that low levels of BCAAs represent the main metabolic fingerprint of acromegaly and that GH, rather than IGF-1, might be the primary mediator. In addition, our results suggest that the assessment of BCAAs could help to identify active disease and to monitor the response to therapeutic strategies
Squeezed tensor non-Gaussianity in non-attractor inflation
We investigate primordial tensor non-Gaussianity in single field inflation,
during a phase of non-attractor evolution when the spectrum of primordial
tensor modes can be enhanced to a level detectable at interferometer scales.
Making use of a tensor duality we introduced in arXiv:1808.10475, we
analytically compute the full bispectrum of primordial tensor fluctuations
during the non-attractor era. During this epoch the shape of the tensor
bispectrum is enhanced in the squeezed limit, its amplitude can be amplified
with respect to slow-roll models, and tensor non-Gaussianity can exhibit a
scale dependence distinctive of our set-up. We prove that our results do not
depend on the frame used for the calculations. Squeezed tensor non-Gaussianity
induces a characteristic quadrupolar anisotropy on the power spectrum of the
stochastic background of primordial tensor perturbations. As a step to make
contact with gravitational wave experiments, we discuss the response function
of a ground based Michelson interferometer to a gravitational wave background
with such a feature.Comment: 34 pages, 4 figure
Euclid: Modelling massive neutrinos in cosmology -- a code comparison
The measurement of the absolute neutrino mass scale from cosmological
large-scale clustering data is one of the key science goals of the Euclid
mission. Such a measurement relies on precise modelling of the impact of
neutrinos on structure formation, which can be studied with -body
simulations. Here we present the results from a major code comparison effort to
establish the maturity and reliability of numerical methods for treating
massive neutrinos. The comparison includes eleven full -body implementations
(not all of them independent), two -body schemes with approximate time
integration, and four additional codes that directly predict or emulate the
matter power spectrum. Using a common set of initial data we quantify the
relative agreement on the nonlinear power spectrum of cold dark matter and
baryons and, for the -body codes, also the relative agreement on the
bispectrum, halo mass function, and halo bias. We find that the different
numerical implementations produce fully consistent results. We can therefore be
confident that we can model the impact of massive neutrinos at the sub-percent
level in the most common summary statistics. We also provide a code validation
pipeline for future reference.Comment: 43 pages, 17 figures, 2 tables; published on behalf of the Euclid
Consortium; data available at https://doi.org/10.5281/zenodo.729797
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Mapping past human land use using archaeological data: A new classification for global land use synthesis and data harmonization.
In the 12,000 years preceding the Industrial Revolution, human activities led to significant changes in land cover, plant and animal distributions, surface hydrology, and biochemical cycles. Earth system models suggest that this anthropogenic land cover change influenced regional and global climate. However, the representation of past land use in earth system models is currently oversimplified. As a result, there are large uncertainties in the current understanding of the past and current state of the earth system. In order to improve representation of the variety and scale of impacts that past land use had on the earth system, a global effort is underway to aggregate and synthesize archaeological and historical evidence of land use systems. Here we present a simple, hierarchical classification of land use systems designed to be used with archaeological and historical data at a global scale and a schema of codes that identify land use practices common to a range of systems, both implemented in a geospatial database. The classification scheme and database resulted from an extensive process of consultation with researchers worldwide. Our scheme is designed to deliver consistent, empirically robust data for the improvement of land use models, while simultaneously allowing for a comparative, detailed mapping of land use relevant to the needs of historical scholars. To illustrate the benefits of the classification scheme and methods for mapping historical land use, we apply it to Mesopotamia and Arabia at 6 kya (c. 4000 BCE). The scheme will be used to describe land use by the Past Global Changes (PAGES) LandCover6k working group, an international project comprised of archaeologists, historians, geographers, paleoecologists, and modelers. Beyond this, the scheme has a wide utility for creating a common language between research and policy communities, linking archaeologists with climate modelers, biodiversity conservation workers and initiatives
Mapping past human land use using archaeological data: A new classification for global land use synthesis and data harmonization
In the 12,000 years preceding the Industrial Revolution, human activities led to significant changes in land cover, plant and animal distributions, surface hydrology, and biochemical cycles. Earth system models suggest that this anthropogenic land cover change influenced regional and global climate. However, the representation of past land use in earth system models is currently oversimplified. As a result, there are large uncertainties in the current understanding of the past and current state of the earth system. In order to improve representation of the variety and scale of impacts that past land use had on the earth system, a global effort is underway to aggregate and synthesize archaeological and historical evidence of land use systems. Here we present a simple, hierarchical classification of land use systems designed to be used with archaeological and historical data at a global scale and a schema of codes that identify land use practices common to a range of systems, both implemented in a geospatial database. The classification scheme and database resulted from an extensive process of consultation with researchers worldwide. Our scheme is designed to deliver consistent, empirically robust data for the improvement of land use models, while simultaneously allowing for a comparative, detailed mapping of land use relevant to the needs of historical scholars. To illustrate the benefits of the classification scheme and methods for mapping historical land use, we apply it to Mesopotamia and Arabia at 6 kya (c. 4000 BCE). The scheme will be used to describe land use by the Past Global Changes (PAGES) LandCover6k working group, an international project comprised of archaeologists, historians, geographers, paleoecologists, and modelers. Beyond this, the scheme has a wide utility for creating a common language between research and policy communities, linking archaeologists with climate modelers, biodiversity conservation workers and initiatives
Advanced Biometric Technologies: Emerging Scenarios and Research Trends
Biometric systems are the ensemble of devices, procedures, and algorithms for the automatic recognition of individuals by means of their physiological or behavioral characteristics. Although biometric systems are traditionally used in high-security applications, recent advancements are enabling the application of these systems in less-constrained conditions with non-ideal samples and with real-time performance. Consequently, biometric technologies are being increasingly used in a wide variety of emerging application scenarios, including public infrastructures, e-government, humanitarian services, and user-centric applications. This chapter introduces recent biometric technologies, reviews emerging scenarios for biometric recognition, and discusses research trends
Infrared divergences for free quantum fields in cosmological spacetimes
We investigate the nature of infrared divergences for the free graviton and
inflaton two-point functions in flat Friedman-Lema\^{\i}tre-Robertson-Walker
spacetime. These divergences arise because the momentum integral for these
two-point functions diverges in the infrared. It is straightforward to see that
the power of the momentum in the integrand can be increased by in the
infrared using large gauge transformations, which are sufficient for rendering
these two-point functions infrared finite for slow-roll inflation. In other
words, if the integrand of the momentum integral for these two-point functions
behaves like , where is the momentum, in the infrared, then it
can be made to behave like by large gauge transformations. On the
other hand, it is known that, if one smears these two-point functions in a
gauge-invariant manner, the power of the momentum in the integrand is changed
from to . This fact suggests that the power of the
momentum in the integrand for these two-point functions can be increased by
using large gauge transformations. In this paper we show that this is indeed
the case. Thus, the two-point functions for the graviton and inflaton fields
can be made finite by large gauge transformations for a large class of
potentials and states in single-field inflation.Comment: 21 pages, no figure
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