Plant by-product antioxidants: control of protein-lipid oxidation in meat and meat products

Financiado para publicación en acceso aberto: Universidade de Vigo/CISUGProtein-lipid oxidation is one of the main causes of quality deterioration in meat and meat products during processing and storage. The application of natural antioxidants in muscle food appears a sustainable option for reducing the consumption of synthetic antioxidants with confirmed carcinogenic and toxicological effects. Hence, the food industry today prefers low-cost natural additives instead of synthetic ones. Agro-food industry generates a large quantity of plant by-products annually during the cultivation and processing of agricultural products. There is a wide variety of natural antioxidants in plant by-products. Several parts of plant (seeds, peels, leaves, husks, stems, and roots) as unexploited novel sources of natural antioxidant can be applied either through technological strategies to control oxidative process in meat and meat products. This paper provides an overview of the current trends in the use of natural antioxidants from plant by-products for potential applications against protein–lipid oxidation in muscle food. In addition, the effect of encapsulation of plant by-product antioxidants on the protein–lipid oxidation of meat and meat products is reviewed.Xunta de Galicia | Ref. IN607A2019/0

Physical exercise as a multimodal tool for COVID-19: Could it be used as a preventive strategy?

Producción CientíficaThe severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) or coronavirus disease 2019 (COVID-19) is a novel coronavirus not previously recognized in humans until late 2019. On 31 December 2019, a cluster of cases of pneumonia of unspecified etiology was reported to the World Health Organization in China. The availability of adequate SARS-CoV-2 drugs is also limited, and the efficacy and safety of these drugs for COVID-2019 pneumonia patients need to be assessed by further clinical trials. For these reasons, there is a need for other strategies against COVID-19 that are capable of prevention and treatment. Physical exercise has proven to be an effective therapy for most chronic diseases and microbial infections with preventive/therapeutic benefits, considering that exercise involves primary immunological mediators and/or anti-inflammatory properties. This review aimed to provide an insight into how the implementation of a physical exercise program against COVID-19 may be a useful complementary tool for prevention, which can also enhance recovery, improve quality of life, and provide immune protection against SARS-CoV-2 virus infection in the long term. In summary, physical exercise training exerts immunomodulatory effects, controls the viral gateway, modulates inflammation, stimulates nitric oxide synthesis pathways, and establishes control over oxidative stress

Galaxy classification: deep learning on the OTELO and COSMOS databases

Context. The accurate classification of hundreds of thousands of galaxies observed in modern deep surveys is imperative if we want to understand the universe and its evolution. Aims. Here, we report the use of machine learning techniques to classify early- and late-type galaxies in the OTELO and COSMOS databases using optical and infrared photometry and available shape parameters: either the Sersic index or the concentration index. Methods. We used three classification methods for the OTELO database: 1) u-r color separation , 2) linear discriminant analysis using u-r and a shape parameter classification, and 3) a deep neural network using the r magnitude, several colors, and a shape parameter. We analyzed the performance of each method by sample bootstrapping and tested the performance of our neural network architecture using COSMOS data. Results. The accuracy achieved by the deep neural network is greater than that of the other classification methods, and it can also operate with missing data. Our neural network architecture is able to classify both OTELO and COSMOS datasets regardless of small differences in the photometric bands used in each catalog. Conclusions. In this study we show that the use of deep neural networks is a robust method to mine the cataloged dataComment: 20 pages, 10 tables, 14 figures, Astronomy and Astrophysics (in press

Detecting microvariability in type 2 quasars using enhanced F-test

Microvariability (intranight variability) is a low amplitude flux change at short time-scales (i.e. hours). It has been detected in unobscured type 1 active galactic nuclei (AGN) and blazars. However in type 2 AGN, the detection is hampered by the low contrast between the presumably variable nucleus and the host galaxy. In this paper, we present a search for microvariability in a sample of four type 2 quasars as an astrostatistical problem. We are exploring the use of a newly introduced enhanced F-test, proposed by Diego. The presented results show that out of four observed target, we are able to apply this statistical method to three of them. Evidence of microvariations is clear in the case of quasar J0802+2552 in all used filters (g?, r? and i?) during both observing nights, and they are present in one of the nights of observations, J1258+5239 in one filter (i?), while for the J1316+4452, there is evidence for microvariability within our detection levels during one night and two filters (r? and i?). We demonstrate the feasibility of the enhanced F-test to detect microvariability in obscured type 2 quasars. At the end of this paper, we discuss possible causes of microvariability. One of the options is the misclassification of the targets. A likely scenario for explanation of the phenomenon involves optically thin gaps in a clumpy obscuring medium, in accordance with the present view of the circumnuclear medium. There is a possible interesting connection between the merging state of the targets and detection of microvariability

The OTELO survey. A case study of [O III]4959,5007 emitters at <z> = 0.83

The OTELO survey is a very deep, blind exploration of a selected region of the Extended Groth Strip and is designed for finding emission-line sources (ELSs). The survey design, observations, data reduction, astrometry, and photometry, as well as the correlation with ancillary data used to obtain a final catalogue, including photo-z estimates and a preliminary selection of ELS, were described in a previous contribution. Here, we aim to determine the main properties and luminosity function (LF) of the [O III] ELS sample of OTELO as a scientific demonstration of its capabilities, advantages, and complementarity with respect to other surveys. The selection and analysis procedures of ELS candidates obtained using tunable filter (TF) pseudo-spectra are described. We performed simulations in the parameter space of the survey to obtain emission-line detection probabilities. Relevant characteristics of [O III] emitters and the LF([O III]), including the main selection biases and uncertainties, are presented. A total of 184 sources were confirmed as [O III] emitters at a mean redshift z=0.83. The minimum detectable line flux and equivalent width (EW) in this ELS sample are $\sim$5 $\times$ 10$^{-19}$ erg s$^{-1}$ cm$^{2}$ and $\sim$6 \AA, respectively. We are able to constrain the faint-end slope ($\alpha = -1.03\pm0.08$) of the observed LF([O III]) at z=0.83. This LF reaches values that are approximately ten times lower than those from other surveys. The vast majority (84\%) of the morphologically classified [O III] ELSs are disc-like sources, and 87\% of this sample is comprised of galaxies with stellar masses of M$_\star$ $<$ 10$^{10}$ M$_{\odot}$.Comment: v1: 16 pages, 6 figures. Accepted in Astronomy \& Astrophysics. v2: Author added in metadat

Valorization of wastewater from table olives: NMR identification of antioxidant phenolic fraction and microwave single-phase reaction of sugary fraction

The table olive industry is producing a huge amount of wastewater, which is a post-processing cost and an environmental concern. The present study aims to valorize this processing by-product to obtain a value-added product, thereby enhancing resource efficiency and contributing to achieving sustainable development goals (SDGs). In this sense, a chemical reaction-based platform was developed to obtain valuable components, such as levulinic acid (LA) and 5-hydromethylfurfural (HMF). The products were then analyzed using NMR identification of the antioxidant phenolic fraction and microwave single-phase reaction of the sugary fraction. According to the results, the highest concentration of phenolic compounds does not correspond to the sample directly obtained from NaOH treatment (S1), indicating that water washing steps (S2-S5) are fundamental to recover phenolic substances. Moreover, glucose was presented in the sugary fraction that can be transformed into levulinic acid by a single-phase reaction under microwave irradiation. The information provided in this manuscript suggests that the wastewater from the olive processing industry can be valorized to obtain valuable products

The OTELO survey: the star formation rate evolution of low-mass galaxies

We present the analysis of a sample of \ha\,, \hb\ and \oii\ emission line galaxies from the \otelo\ survey, with masses typically below log(M_*/M_\sun) \sim 9.4 and redshifts between $z \sim 0.4$ and 1.43. We study the star formation rate, star formation rate density, and number density and their evolution with redshift. We obtain a robust estimate of the specific star formation rate -- stellar mass relation based on the lowest mass sample published so far. We also determine a flat trend of the star formation rate density and number density with redshift. Our results suggest a scenario of no evolution of the number density of galaxies, regardless of their masses, up to redshift $z\sim1.4$. This implies a gradual change of the relative importance of the star forming processes, from high-mass galaxies to low-mass galaxies, with decreasing redshift. We also find little or no variation of the star formation rate density in the redshift range of $0.4<z<1.43$.Comment: 8 pages, 3 figures, accepted for publication in ApJ letter

Table olive wastewater as a potential source of biophenols for valorization : a mini review

The table olive industry generates high amounts of wastewater annually during the alkaline treatment, fermentation, and washing steps of olives. High conductivity and salt content, as well as the high organic and biophenol contents of these waters, is a worldwide problem, especially in the Mediterranean region, which is the major table olive producing area. There is a wide variety of bioactives found in wastewater derived from table olive processing. The main compounds of table olive wastewater, such as those derived from phenolic, hydrocarbon, and sugar fractions, can be recovered and reused. In this review, the table olive manufacturing processes and the volumes and composition of wastewater generated from the different methods of table olive processing are discussed. In addition, biophenols of table olive water and their biological activities are also introduced. The high concentrations of valuable biophenols, such as tyrosol and hydroxytyrosol, show promising potential for valorizing table olive wastewater; however, more research is needed in this area

San Pedro Mártir observations of microvariability in obscured quasars

Fast brightness variations are a unique tool to probe the innermost regions of active galactic nuclei (AGN). These variations are called microvariability or intra-night variability, and this phenomenon has been monitored in samples of blazars and unobscured AGNs. Detecting optical microvariations in targets hidden by the obscuring torus is a challenging task because the region responsible for the variations is hidden from our sight. However, there have been reports of fast variations in obscured Seyfert galaxies in X-rays, which rises the question whether microvariations can also be detected in obscured AGNs in the optical regime. Because the expected variations are very small and can easily be lost within the noise, the analysis requires a statistical approach. We report the use of a one-way analysis of variance, ANOVA, with which we searched for microvariability. ANOVA was successfully employed in previous studies of unobscured AGNs. As a result, we found microvariable events during three observing blocks: in two we observed the same object (Mrk 477), and in another, J0759+5050. The results on Mrk 477 confirm previous findings. However, since Mrk 477 is quite a peculiar target with hidden broad-line regions, we cannot rule out the possibility that we have serendipitously chosen a target prone to variations.This research has been supported by the Spanish Ministerio de Economía y Competitividad (MINECO) under the grant AYA2014-58861-C3-1. I.O. acknowledges support from the European Research Council (ERC) in the form of Advanced Grant, COSMICISM. J.A.D. is grateful for the support from the grant UNAM-DGAPA-PAPIIT IN110013 Program and the Canary islands CIE: Tricontinental Atlantic Campus. A.E. acknowledges support by the grant AYA2012-30789. J. I. González-Serrano is grateful for the support from AYA2011-29517-C03-02.Peer Reviewe