Suchergebnisse

Avian embryos are exposed to yolk androgens that are incorporated into the egg by the ovulating female. These steroids can affect several aspects of embryo development, often resulting in increases in overall size or the speed of growth of different traits. However, several studies suggest that they also entail immune costs to the offspring. In this study, we explored whether variation in yolk androgen concentration affected several measures of the constitutive and cell-mediated immune axes in the spotless starling (Sturnus unicolor). Using a within-brood design, we injected different doses of androgens (testosterone and androstenedione) into the eggs. Our study showed that experimentally increased yolk androgens led to sex-specific immunosuppression in both the innate and adaptive axes of the immune system. Both cell-mediated immune response (CMI) and lysozyme activity decreased with increasing androgen levels injected into the egg in the case of male nestlings, whereas there were no effects on females. The effects that we found were always linear: no quadratic or threshold patterns were detected. We found no effects of the experimental treatment in hemolysis or agglutination capacity, but these measures were negatively correlated with CMI, suggesting negative correlation among different branches of the immune system. Blood (trypanosomes and hemosporidians) and intestinal (coccidia) parasites were not affected by the experimental increase of yolk androgen levels. Our results show that in our study species yolk androgens induce immunosuppression in some axes of the male nestling immune system. Further studies should analyze the proximate causes for these contrasting effects in different axes of the immune system and the reason for the differential impact on males and females. ; This study was financed by project grants CGL2008–03501 and CGL2011–26318 to D.G. (Ministerio de Ciencia e Innovación [MICINN]). J.M. was supported by an FPI (Formación de Personal Investigador) grant (BES-2009–021383) from MICINN. L.P.-R. was supported by a postdoctoral grant from MICINN through the Juan de la Cierva Subprogram (JCI-2008–2059), followed by a postdoctoral contract from the Spanish Ministry of Economy and Competitiveness through the Severo Ochoa Program for Centres of Excellence in Research, Development, and Innovation (SEV-2012–0262). M.E.O.-S. was supported by a postdoctoral grant from MICINN through the Juan de la Cierva Subprogram (JCI-2009–03865), followed by a Marie Curie Intra-European Fellowship of the European Union's 7th Framework Program (2012–328328). ; Peer reviewed

Large polycyclic o-(trimethylsilyl)aryl triflates are easily obtained by reaction of commercially available bisaryne precursors with cyclopentadienones. The transformation involves controlled generation of one of the aryne functionalities, trapping by Diels–Alder reaction with a dienone, and chelotropic extrusion of CO. The newly synthesized triflates are precursors of acene-based arynes, including a didehydropentacene ; Financial support from the Spanish Ministry of Science and Competitiveness (MINECO, CTQ2013-44142-P and MAT2013-46593-C6-6-P), the European Union (Project PAMS, contract no. 610446), Xunta de Galicia (GPC2014/25), and FEDER is gratefully acknowledged. D.R.-L. thanks the Spanish Ministry of Education for the award of an FPU fellowship ; SI

The synthesis of an efficient precursor of the novel 1,7-naphthodiyne synthon is reported. Preliminary experiments demonstrate the usefulness of this platform for the synthesis of sterically congested polyarenes, such as helicenes and angularly fused acene derivatives. Furthermore, a novel intramolecular aryne trapping reaction is described ; Financial support from the Spanish Ministry of Economy and Competitiveness (MINECO, CTQ2013-44142-P and MAT2013-46593-C6-6-P), the European Union (Project PAMS, contract no. 610446), Xunta de Galicia (GPC2014/25) and FEDER is gratefully acknowledged ; SI

Turning graphene magnetic is a promising challenge to make it an active material for spintronics. Predictions state that graphene structures with specific shapes can spontaneously develop magnetism driven by Coulomb repulsion of π-electrons, but its experimental verification is demanding. Here, we report on the observation and manipulation of individual magnetic moments in graphene open-shell nanostructures on a gold surface. Using scanning tunneling spectroscopy, we detect the presence of single electron spins localized around certain zigzag sites of the carbon backbone via the Kondo effect. We find near-by spins coupled into a singlet ground state and quantify their exchange interaction via singlet-triplet inelastic electron excitations. Theoretical simulations picture how electron correlations result in spin-polarized radical states with the experimentally observed spatial distributions. Extra hydrogen atoms bound to radical sites quench their magnetic moment and switch the spin of the nanostructure in half-integer amounts. Our work demonstrates the intrinsic π-paramagnetism of graphene nanostructures ; We acknowledge financial support from Spanish AEI (MAT2016-78293-C6, FIS2017-83780-P, and the Maria de Maeztu Units of Excellence Program MDM-2016-0618), the Basque Government (Department of Education, Grant PI-2015-1-42), the EU project PAMS (610446), the Xunta de Galicia (Centro singular de investigación de Galicia accreditation 2016-2019, ED431G/09), and the European Regional Development Fund (ERDF) ; SI

This work has been partially supported by the Ministry of Science and Technology under project TIN2017-89517-P, the Contract UGR-AM OTRI-4260 and the Andalusian Excellence project P18-FR-4961. J. Carrasco was supported by the Spanish Ministry of Science under the FPU Programme 998758-2016. D. Garcia-Gil holds a contract co-financed by the European Social Fund and the Administration of the Junta de Andalucia, reference DOC_01137. ; The research in anomaly detection lacks a unified definition of what represents an anomalous instance. Discrepancies in the nature itself of an anomaly lead to multiple paradigms of algorithms design and experimentation. Predictive maintenance is a special case, where the anomaly represents a failure that must be prevented. Related time series research as outlier and novelty detection or time series classification does not apply to the concept of an anomaly in this field, because they are not single points which have not been seen previously and may not be precisely annotated. Moreover, due to the lack of annotated anomalous data, many benchmarks are adapted from supervised scenarios. To address these issues, we generalise the concept of positive and negative instances to intervals to be able to evaluate unsupervised anomaly detection algorithms. We also preserve the imbalance scheme for evaluation through the proposal of the Preceding Window ROC, a generalisation for the calculation of ROC curves for time series scenarios. We also adapt the mechanism from a established time series anomaly detection benchmark to the proposed generalisations to reward early detection. Therefore, the proposal represents a flexible evaluation framework for the different scenarios. To show the usefulness of this definition, we include a case study of Big Data algorithms with a real-world time series problem provided by the company ArcelorMittal, and compare the proposal with an evaluation method. ; Ministry of Science and Technology TIN2017-89517-P ; Contract UGR-AM OTRI-4260 ; Andalusian Excellence project P18-FR-4961 ; Spanish Government 998758-2016 ; European Social Fund (ESF) ; Junta de Andalucia DOC_01137

Glaser‐like coupling of terminal alkynes by thermal activation is extensively used in on‐surface chemistry. Here we demonstrate an intramolecular version of this reaction performed by atom manipulation. We used voltage pulses from the tip to trigger a Glaser‐like coupling between terminal alkyne carbons within a custom‐synthesized precursor molecule adsorbed on bilayer NaCl on Cu(111). Different conformations of the precursor molecule and the product were characterized by molecular structure elucidation with atomic force microscopy and orbital density mapping with scanning tunneling microscopy, accompanied by density functional theory calculations. We revealed partially dehydrogenated intermediates, providing insight into the reaction pathway ; We thank the European Union (Project SPRING, contract no. 863098), the ERC grant AMSEL (682144), the Spanish Agencia Estatal de Investigación (MAT2016-78293-C6-3-R and CTQ2016-78157-R), Xunta de Galicia (Centro de Investigación de Galicia accreditation 2019–2022, ED431G 2019/03) and the EuropeanRegional Development Fund-ERDF for financial support ; SI

We propose that peptides are highly versatile platforms for the precise design of supramolecular metal architectures, and particularly, for the controlled assembly of helicates. In this context, we show that the bacteriophage T4 Fibritin foldon (T4Ff) can been engineered on its N-terminus with metal-chelating 2,2′-bipyridine units that stereoselectively assemble in the presence of Fe(II) into parallel, three-stranded peptide helicates with preferred helical orientation. Modeling studies support the proposed self-assembly and the stability of the final helicate. Furthermore, we show that these designed mini-metalloproteins selectively recognize three-way DNA junctions over double-stranded DNA ; Financial support from the Spanish grants CTQ2015-70698-R, CTQ2017-87889-P, the Xunta de Galicia (Centro singular de investigación de Galicia accreditation 2016–2019, ED431G/09) and the European Union (European Regional Development Fund - ERDF), is gratefully acknowledged. JG-G, thanks the Spanish MINECO for his FPI fellowship, GB thanks the ERC for her EU METALIC-II 2013-2442/001-001-EMA2 mobility scheme fellowship, and GS. thanks the Universitat Autònoma de Barcelona for its support to his PhD. J-DM and GS are thankful for the support given by the Generalitat de Catalunya 2017SGR1323. Support of COST Action CM1306 is kindly acknowledged. MEV, also wish to acknowledge the generous support by the Fundación Asociación Española Contra el Cáncer AECC (IDEAS197VAZQ grant) ; SI

Urbanization changes the landscape structure and ecological processes of natural habitats. While urban areas expose animal communities to novel challenges, they may also provide more stable environments in which environmental fluctuations are buffered. Species´ ecology and physiology may determine their capacity to cope with the city life. However, the physiological mechanisms underlying organismal responses to urbanization, and whether different physiological systems are equally affected by urban environments remain poorly understood. This severely limits our capacity to predict the impact of anthropogenic habitats on wild populations. In this study, we measured indicators of physiological stress at the endocrine, immune and cellular level (feather corticosterone levels, heterophil to lymphocyte ratio, and heat-shock proteins) in urban and non-urban European blackbirds (Turdus merula) across 10 European populations. Among the three variables, we found consistent differences in feather corticosterone, which was higher in non-urban habitats. This effect seems to be dependent on sex, being greater in males. In contrast, we found no significant differences between urban and non-urban habitats in the two other physiological indicators. The discrepancy between these different measurements of physiological stress highlights the importance of including multiple physiological variables to understand the impact of urbanization on species' physiology. Overall, our findings suggest that adult European blackbirds living in urban and non-urban habitats do not differ in terms of physiological stress at an organismal level. Furthermore, we found large differences among populations on the strength and direction of the urbanization effect, which illustrates the relevance of spatial replication when investigating urban-induced physiological responses. ; JDI was funded by a postdoctoral contract (TAHUB-104) from the program "Andalucía Talent Hub" (co-funded by the European's Union Seventh Framework Program Marie Skłodowska-Curie actions -COFUND- and the regional Government of Andalucía). DG was funded by a research grant from the Spanish Ministerio de Ciencia, Innovación y Universidades (CGL2014-55577-R). JF was funded by a research grant from the Spanish Ministerio de Economía y Competitividad (CGL2012-30759). ADF was supported by a Severo-Ochoa grant from the Spanish Ministerio de Economía y Competitividad (SVP-2014-068571). ; Peer reviewed