149 research outputs found
Measuring the transition to homogeneity with photometric redshift surveys
We study the possibility of detecting the transition to homogeneity using
photometric redshift catalogs. Our method is based on measuring the fractality
of the projected galaxy distribution, using angular distances, and relies only
on observable quantites. It thus provides a way to test the Cosmological
Principle in a model-independent unbiased way. We have tested our method on
different synthetic inhomogeneous catalogs, and shown that it is capable of
discriminating some fractal models with relatively large fractal dimensions, in
spite of the loss of information due to the radial projection. We have also
studied the influence of the redshift bin width, photometric redshift errors,
bias, non-linear clustering, and surveyed area, on the angular homogeneity
index H2 ({\theta}) in a {\Lambda}CDM cosmology. The level to which an upcoming
galaxy survey will be able to constrain the transition to homogeneity will
depend mainly on the total surveyed area and the compactness of the surveyed
region. In particular, a Dark Energy Survey (DES)-like survey should be able to
easily discriminate certain fractal models with fractal dimensions as large as
D2 = 2.95. We believe that this method will have relevant applications for
upcoming large photometric redshift surveys, such as DES or the Large Synoptic
Survey Telescope (LSST).Comment: 14 pages, 14 figure
The CDM growth rate of structure revisited
We re-examine the growth index of the concordance cosmology in the
light of the latest 6dF and {\em WiggleZ} data. In particular, we investigate
five different models for the growth index , by comparing their
cosmological evolution using observational data of the growth rate of structure
formation at different redshifts. Performing a joint likelihood analysis of the
recent supernovae type Ia data, the Cosmic Microwave Background shift
parameter, Baryonic Acoustic Oscillations and the growth rate data, we
determine the free parameters of the parametrizations and we
statistically quantify their ability to represent the observations. We find
that the addition of the 6dF and {\em WiggleZ} growth data in the likelihood
analysis improves significantly the statistical results. As an example,
considering a constant growth index we find and
.Comment: 8 pages, 5 figures, Accepted for publication by International J. of
Modern Physics D (IJMPD). arXiv admin note: substantial text overlap with
arXiv:1203.672
Phenolic-rich extracts from avocado fruit residues as functional food ingredients with antioxidant and antiproliferative properties
In this study, the total phenolic compounds content and profile, the nutritional value, the antioxidant and antiproliferative activities of avocado peel, seed coat, and seed extracts were characterized. Additionally, an in-silico analysis was performed to identify the phenolic compounds with the highest intestinal absorption and Caco-2 permeability. The avocado peel extract possessed the highest content of phenolic compounds (309.95 ± 25.33 mMol GA/100 g of extract) and the lowest effective concentration (EC50) against DPPH and ABTS radicals (72.64 ± 10.70 and 181.68 ± 18.47, respectively). On the other hand, the peel and seed coat extracts had the lowest energy densities (226.06 ± 0.06 kcal/100g and 219.62 ± 0.49 kcal/100g, respectively). Regarding the antiproliferative activity, the avocado peel extract (180 ± 40 ”g/mL) showed the lowest inhibitory concentration (IC50), followed by the seed (200 ± 21 ”g/mL) and seed coat (340 ± 32 ”g/mL) extracts. The IC50 of the extracts induced apoptosis in Caco-2 cells at the early and late stages. According to the in-silico analysis, these results could be related to the higher Caco-2 permeability to hy-droxysalidroside, salidroside, sakuranetin, and luteolin. Therefore, this study provides new insights regarding the potential use of these extracts as functional ingredients with antioxidant and antiproliferative properties and as medicinal agents in diseases related to oxidative stress such as cancer. © 2021 by the authors. Licensee MDPI, Basel, Switzerland
Is there an association between sleep disorders and diabetic foot? A scoping review
Diabetic foot is associated with a low quality of life since physical disabilities, mood
disturbances and psychological disorders are frequent. One of the most important biological processes
to ensure quality of life is sleep. Sleep disorders can impair glycemic control in patients with
diabetes mellitus or even cause long-term type 2 diabetes mellitus. The aim of this study is to
carry out a scoping review about the association between sleep cycle disorders and diabetic foot.
PubMed, Scopus, CINAHL, PEDro, Cochrane Library, SCIELO and EMBASE databases were chosen
for the search and the following terms were used: âdiabetic footâ,âsleep*â,ârest-activityâ,âmoodâ
andâbehaviorâ. All the studies should include outcome variables about sleep and diabetic foot.
Finally, 12 articles were selected, all of whichwere observational. The most frequent variables were
those regarding diabetic foot ulcer aspects and diabetic neuropathy on one side, and obstructive
sleep apnea, sleep duration and sleep quality on the other side. The results suggest that there is a
possible association between obstructive sleep apnea and the presence or history of diabetic foot
ulcers. No direct associations between sleep quality or sleep duration and diabetic foot or diabetic
foot ulcer variables have been found
Ovine enzootic ataxia. It's histopathological evolution
Se describen las lesiones histo patológicas correspondientes a casos de ovinos con procesos de ataxia, consistentes en cromatolisis de las neuronas y procesos avanzados de desmielinización. Las zonas del SNC mås afectadas correspondieron a la zona lumbar, cervical y toråcica de la médula espinal y a la corteza cerebelosa. Los anålisis efectuados de dosajes de cobre no coinciden con los valores inferiores descritos por otros autores para esta enfermedad.Histopathologic lesions of ovines with ataxia are described. They const of neurone chromatolysis and advanced processes of desmylinization. The cerebellar cortex, the cervical, thoracic and lumbar medulla were de most affected zones of the Central Nervous System. The cooper dosages of the liver made by polarography differed with the minimum levels reported by other research workers for this disease.Facultad de Ciencias Veterinaria
A parametrization of the growth index of matter perturbations in various Dark Energy models and observational prospects using a Euclid-like survey
We provide exact solutions to the cosmological matter perturbation equation
in a homogeneous FLRW universe with a vacuum energy that can be parametrized by
a constant equation of state parameter and a very accurate approximation
for the Ansatz . We compute the growth index \gamma=\log
f(a)/\log\Om_m(a), and its redshift dependence, using the exact and
approximate solutions in terms of Legendre polynomials and show that it can be
parametrized as in most cases. We then
compare four different types of dark energy (DE) models: CDM, DGP,
and a LTB-large-void model, which have very different behaviors at
z\gsim1. This allows us to study the possibility to differentiate between
different DE alternatives using wide and deep surveys like Euclid, which will
measure both photometric and spectroscopic redshifts for several hundreds of
millions of galaxies up to redshift . We do a Fisher matrix analysis
for the prospects of differentiating among the different DE models in terms of
the growth index, taken as a given function of redshift or with a principal
component analysis, with a value for each redshift bin for a Euclid-like
survey. We use as observables the complete and marginalized power spectrum of
galaxies and the Weak Lensing (WL) power spectrum. We find that, using
, one can reach (2%, 5%) errors in , and (4%, 12%) errors in
, while using WL we get errors at least twice as large.
These estimates allow us to differentiate easily between DGP, models and
CDM, while it would be more difficult to distinguish the latter from a
variable equation of state parameter or LTB models using only the growth
index.}Comment: 29 pages, 7 figures, 6 table
A web application to optimization of transport in military operations
Transport is an operation necessary to carry out any logistical mission, especially in times of war, peace or natural disasters. The distribution of the necessary demanded resources is done from a military unit, to the different locations or military bases. However, operational efficiency depends on the planners. In more than 60% of trips, shipping and return isnât efficient, even between the same units. The cause is the non-consolidation of trips and the lack of return load, coming from perimeter units. Planning is done without consolidating trips and in many cases on demand. Itâs presented a web application, a parametric framework to any geographical area, given the integration with applications such as Google MapsÂź. Computational times are reasonable, given a to hardiness to the problem. The software architecture is scalable and extensible, complying with software quality practices present in ISO 25000
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