Diet of larval albacore Thunnus alalunga (Bonnaterre, 1788) off Mallorca Island (NW Mediterranean)

These are the first data on the feeding of larval albacore (Thunnus alalunga Bonnaterre, 1788) in the Mediterranean. Specimens were gathered from day-time bongo-hauls conducted over the SW Mallorcan (Balearic Islands) shelf-slope. Ninety eight percent of 101 individuals ranging from 2.65 to 9.4 mm standard length (SL) contained 1 to 15 prey items per gut. Mean number of prey/gut was 3.55 ± 2.19 (SD). A positive correlation was found between larval SL and the number of prey/gut. The analysis of frequency of occurrence (F), numerical frequency (N), weight frequency (W) and the Index of Relative Importance (IRI) showed a dominance of copepodites and nauplii in the smallest size-class. As larvae grew, cladocerans and Calanoida copepodites dominated the diet, and cladocerans and copepodites were important in F, N and W. Piscivory was observed after notochord flexion and was important in terms of W. A positive correlation between mean prey size and both SL and lower jaw length (LJL) was observed. The niche breadth (S) did not vary with LJL, but the raw prey size range did. Larger copepodites, the absence of nauplii and the incorporation of fish larvae and a larger number of cladocerans in the diet accounted for the increase in mean prey size through increased larval size.DIETA DE LAS LARVAS DE ALBACORA THUNNUS ALALUNGA (BONNATERRE, 1788) EN AGUAS DE MALLORCA (MEDITERRÁNEO NW). – Se ofrecen los primeros datos sobre la dieta de las larvas de albacora (Thunnus alalunga Bonaterre, 1788) en el Mediterráneo. Los especímenes se obtuvieron de pescas diurnas con bongo sobre la plataforma-talud al SW de Mallorca (Islas Baleares). El 98% de 101 individuos de entre 2.65 y 9.4 mm de longitud estándar (LE) contuvieron entre 1 y 15 presas por digestivo. La media de presas por larva fue de 3.55 ± 2.19 (DE), existiendo una correlación positiva entre el número de presas en el tubo digestivo y la LS. Los índices de frecuencia de ocurrencia (F), frecuencia numérica (N), frecuencia en peso (W) y el Índice de Importancia Relativa (IRI) mostraron un predominio de copepoditos y nauplius en larvas pequeñas, disminuyendo en importancia a lo largo del crecimiento en detrimento de cladóceros y copepoditos de Calanoida, que fueron importantes en F, N y W. Se observó piscivoría, importante en W, a partir de la flexión de la notocorda. Se detectó una correlación positiva entre el tamaño medio de las presas y tanto la LS como la longitud de la maxila (LJL) de las larvas. La amplitud del nicho alimentario (S) no varió con la LJL, aunque el rango total del tamaño de las presas sí lo hizo. El aumento de talla de los copepoditos, la desaparición progresiva de mauplius y la incorporación de larvas de peces y más cladóceros explica el aumento de la talla media de las presas a lo largo del crecimiento larvario.Versión del editor1,006

The space density distribution of galaxies in the absolute magnitude - rotation velocity plane: a volume-complete Tully-Fisher relation from CALIFA stellar kinematics

The space density distribution of galaxies in the absolute magnitude - rotation velocity plane: a volume-complete Tully-Fisher relation from CALIFA stellar kinematicsComment: Accepted to A&

Comparative plastome genomics and phylogenomics of Brachypodium: flowering time signatures, introgression and recombination in recently diverged ecotypes

Few pan-genomic studies have been conducted in plants, and none of them have focused on the intraspecific diversity and evolution of their plastid genomes. We address this issue in Brachypodium distachyon and its close relatives B. stacei and B. hybridum, for which a large genomic data set has been compiled. We analyze inter- and intraspecific plastid comparative genomics and phylogenomic relationships within a family-wide framework. Major indel differences were detected between Brachypodium plastomes. Within B. distachyon, we detected two main lineages, a mostly Extremely Delayed Flowering (EDF+) clade and a mostly Spanish (S+) – Turkish (T+) clade, plus nine chloroplast capture and two plastid DNA (ptDNA) introgression and micro-recombination events. Early Oligocene (30.9 million yr ago (Ma)) and Late Miocene (10.1 Ma) divergence times were inferred for the respective stem and crown nodes of Brachypodium and a very recent Mid-Pleistocene (0.9 Ma) time for the B. distachyon split. Flowering time variation is a main factor driving rapid intraspecific divergence in B. distachyon, although it is counterbalanced by repeated introgression between previously isolated lineages. Swapping of plastomes between the three different genomic groups, EDF+, T+, S+, probably resulted from random backcrossing followed by stabilization through selection pressure

Biodegradation kinetics of dissolved organic matter chromatographic fractions

Controls on the degradation of dissolved organic matter (DOM) are complex but key to understand the role of freshwaters in the carbon cycle. Both the origin and previous degradation history have been suggested to determine DOM reactivity, but it is still a major challenge to understand the links between DOM composition and biodegradation kinetics. An appropriate context to study these links are intermittent rivers, as summer drought naturally diversifies DOM sources and sinks. Here we investigated the biodegradation kinetics of DOM in the main aquatic environments present in a temporary river. During dark incubations we traced the dynamics of bulk DOM and its main chromatographic fractions defined using LC-OCD: high molecular weight substances (HMWS), low molecular weight substances (LMWS), and humic substances and building blocks. Bulk DOM decay patterns were successfully fitted to the reactivity continuum (RC) biodegradation model. The RC parameters depicted running waters as the sites presenting a more reactive DOM, and temporary pools, enriched in leaf litter, as the ones with slowest DOM decay. The decay patterns of each DOM fraction were consistent throughout sites. LMWS and HMWS decayed in all cases and could be modeled using the RC model. Notably, the dynamics of LMWS controlled the bulk DOM kinetics. We discuss the mechanistic basis for the chromatographic fractions' kinetics during biodegradation and the implications that preconditioning and summer drought can have for DOM biodegradation in intermittent rivers

Changing attitudes toward redistribution: The role of perceived economic inequality in everyday life and intolerance of inequality

Modern societies are characterized by economic inequality. Redistributive policies are one of the means to reduce it. We argue that perceived economic inequality in everyday life and intolerance of it are central factors to enhance positive attitudes toward redistribution. To test it, we conducted a four-wave longitudinal panel study in Chile with a sample of 1221 college students (at T1 – baseline, 960 at T2, 926 at T3, and 787 at T4; Mage = 18.89). As expected, a cross-lagged longitudinal analysis controlled by household income confirmed a positive relationship between perceived economic inequality in everyday life and intolerance of inequality, which in turn was positively associated with support for redistributive policies. These results were stable and consistent over time, supporting the idea that perceived economic inequality in everyday life enhances positive attitudes toward redistribution by increasing intolerance of it. Results highlight the important role played by perceived inequality in everyday life.Chilean National Foundation for Scientific and Technological Development/[#1161371]/FONDECYT/ChileCenter for Social Conflict and Cohesion Studies/[ANID/FONDAP #15130009]/COES/ChileCenter for Intercultural and Indigenous Research/[ANID/FONDAP #15110006]/CIIR/ChileMinistry of Economy and Competitiveness/[PSI2016-78839-P]/MINECO/EspañaUniversidad de Costa Rica/[OAICE-006-2017]/UCR/Costa RicaUCR::Sedes Regionales::Sede de Occident

Comparative genomics, evolution, and drought-induced expression of dehydrin genes in model Brachypodium grasses

Dehydration proteins (dehydrins, DHNs) confer tolerance to water-stress deficit in plants. We performed a comparative genomics and evolutionary study of DHN genes in four model Brachy-podium grass species. Due to limited knowledge on dehydrin expression under water deprivation stress in Brachypodium, we also performed a drought-induced gene expression analysis in 32 ecotypes of the genus’ flagship species B. distachyon showing different hydric requirements. Genomic sequence analysis detected 10 types of dehydrin genes (Bdhn) across the Brachypodium species. Domain and conserved motif contents of peptides encoded by Bdhn genes revealed eight protein architectures. Bdhn genes were spread across several chromosomes. Selection analysis indicated that all the Bdhn genes were constrained by purifying selection. Three upstream cis-regulatory motifs (BES1, MYB124, ZAT) were detected in several Bdhn genes. Gene expression analysis demonstrated that only four Bdhn1-Bdhn2, Bdhn3, and Bdhn7 genes, orthologs of wheat, barley, rice, sorghum, and maize genes, were expressed in mature leaves of B. distachyon and that all of them were more highly expressed in plants under drought conditions. Brachypodium dehydrin expression was significantly correlated with drought-response phenotypic traits (plant biomass, leaf carbon and proline contents and water use efficiency increases, and leaf water and nitrogen content decreases) being more pronounced in drought-tolerant ecotypes. Our results indicate that dehydrin type and regulation could be a key factor determining the acquisition of water-stress tolerance in grasses. © 2021 by the authors. Licensee MDPI, Basel, Switzerland

Periodic variability of spotted M dwarfs in WTS

This is an Open Access article distributed under the terms of the Creative Commons Attribution License 2.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.We present an analysis of the photometric variability of M dwarfs in the WFCAM Transit Survey, selected from spectral types inferred by their WTS and SDSS colours, with periods detected using a Lomb-Scargle Periodogram Analisys. We estimate population membership of these objects from their tangential velocities and photometric parralaxes. Examples of M dwarfs with variable light curve morphologuies are found. We discuss possible causes for this and make use of models of spotted stars in our interpretation of the results

Features of the Extension of a Statistical Measure of Complexity to Continuous Systems

We discuss some aspects of the extension to continuous systems of a statistical measure of complexity introduced by Lopez-Ruiz, Mancini and Calbet (LMC) [Phys. Lett. A 209 (1995) 321]. In general, the extension of a magnitude from the discrete to the continuous case is not a trivial process and requires some choice. In the present study, several possibilities appear available. One of them is examined in detail. Some interesting properties desirable for any magnitude of complexity are discovered on this particular extension.Comment: 22 pages, 0 figure

Size-selective breaking of the core-shell structure of gallium nanoparticles

This Accepted Manuscript is available for reuse under a CC BY-NC-ND 3.0 licence after the 12 month embargo period provided that all the terms of the licence are adhered toCore-shell gallium nanoparticles (Ga NPs) have recently been proposed as an ultraviolet plasmonic material for different applications but only at room temperature. Here, the thermal stability as a function of the size of the NPs is reported over a wide range of temperatures. We analyze the chemical and structural properties of the oxide shell by x-ray photoelectron spectroscopy and atomic force microscopy. We demonstrate the inverse dependence of the shell breaking temperature with the size of the NPs. Spectroscopic ellipsometry is used for tracking the rupture and its mechanism is systematically investigated by scanning electron microscopy, grazing incidence x-ray diffraction and cathodoluminescence. Taking advantage of the thermal stability of the NPs, we perform complete oxidations that lead to homogenous gallium oxide NPs. Thus, this study set the physical limits of Ga NPs to last at high temperatures, and opens up the possibility to achieve totally oxidized NPs while keeping their sphericityThe research is supported by the MINECO (CTQ2014-53334-C2-2-R, CTQ2017-84309-C2-2-R, MAT2016-80394-R, MAT 2015-65274-R/FEDER and MAT2017-85089-C2-1-R) and Comunidad de Madrid (NANOAVANSENS ref. S2013/MIT-3029) projects. ARC acknowledges Ramón y Cajal program (under contract number RYC-2015-18047). FN acknowledges support from Marie Sklodowska-Curie grant agreement No. 641899 from the European Union´s Horizon 2020 research and innovation programm