3,631 research outputs found
Sport Center C.A.R.D., Las Rozas, Madrid (1987)
No full textSport Center C.A.R.D., Las Rozas, Madrid (1987
Global properties of the population of H
No full textWe present a new high quality continuum-subtracted Hα image of
NGC 7479. Using a novel semi-automated technique we have determined the
positions, angular sizes, and absolute fluxes of over 1000 Hi
NADES-assisted sample preparation as a greener alternative for mycotoxins determination in apple-based products
No full textWhile impressive advancements have been reported in mycotoxin analysis over the last decade, very little has been done to realign the sample treatment to the green sample preparation principles, which are arising more and more relevance in the current analytical chemistry. In this regard, this work proposes the first NADES-assisted sample preparation for the extraction of mycotoxins in food samples. Two protocols using dispersive liquid–liquid microextraction (DLLME) and DLLME with solidification of floating organic drop (DLLME-SFO) assisted with a natural deep eutectic solvent (NADES) were developed and assessed as green sample preparation procedures to extract mycotoxins from apple-based products prior to HPLC-MS/MS analysis. The selected mycotoxins were alternariol, alternariol monomethyl ether, tentoxin and ochratoxin A, which are known to occur in these food matrices. The main variables affecting the extraction efficiency, such as volume of dispersive and extraction solvents, as well as the salting-out effect were evaluated and optimized using a central composite design. In addition, both methodologies were examined and compared in terms of greenness using the newly released metric tool AGREEprep. Due to the use of NADES, the DLLME-SFO method achieved a higher greenness score, and it was selected for further characterization. Matrix-matched calibration curves were used, showing a satisfactory linearity (R2 > 0.99). Limits of detection (LODs) and quantification (LOQs) were below 0.25 and 0.8 μg kg−1, respectively. Recoveries were above 72 % for all the mycotoxins studied in both apple juice and apple puree samples. The validated DLLME-SFO-HPLC-MS/MS method was applied to the analysis of commercial apple juice and puree samples. All the samples analysed were contaminated with at least one mycotoxin with a total concentration ranging from 0.4 to 10.5 μg kg−1
Occurrence of Ergot Alkaloids in Major and Minor Cereals from Northern Italy: A Three Harvesting Years Scenario
No full textErgot alkaloids (EAs), mycotoxins produced mainly by fungi of the Claviceps genus, have been frequently reported in rye, while their increasingly frequent occurrence in other cereals is likely related to weather conditions, with the incidence of ergot sclerotia in winter grains being related to heavy rainfall and moist soils at critical periods. However, compared to other regulated mycotoxins, data about the prevalence and occurrence of EAs in major and minor cereals harvested in the Mediterranean growing areas are still scant. In this regard, the current study reported the occurrence of EAs in 18 genotypes of winter cereals harvested over 3 years from an experimental field located in North Italy which were analyzed by HPLC-MS/MS. Results indicate a widespread occurrence of all the major EAs in all the considered cereal crops, especially under supportive meteorological conditions. EA contamination was dependent on the harvest year (p < 0.0001) which was particularly high in 2020 for all the considered species. The results also demonstrated a large co-occurrence of EAs with 98 cereal samples out of 162 contaminated with at least one of the 12 EAs (60% positive samples) in the range LOD: 15,389 μg/kg (median value: 2.32 μg/kg), expressed as the sum of the EAs. Rye was confirmed to be the crop more susceptible to the fungal infection (EAs content up to 4,302 μg/kg). To the best of our knowledge, we have reported the accumulation of EAs in tritordeum (LOD: 15,389 μg/kg) and in emmer (LOD: 1.9 μg/kg) for the first time
Comparative genomics uncovers unique gene turnover and evolutionary rates in a gene family involved in the detection of insect cuticular pheromones
No full textChemoreception is an essential process for the survival and reproduction of animals. Many of the proteins responsible for recognizing and transmitting chemical stimuli in insects are encoded by genes that are members of moderately sized multigene families. The members of the CheB family are specialized in gustatory-mediated detection of long-chain hydrocarbon pheromones in Drosophila melanogaster and play a central role in triggering and modulating mating behavior in this species. Here, we present a comprehensive comparative genomic analysis of the CheB family across 12 species of the Drosophila genus. We have identified a total of 102 new CheB genes in the genomes of these species, including a functionally divergent member previously uncharacterized in D. melanogaster. We found that, despite its relatively small repertory size, the CheB family has undergone multiple gain and loss events and various episodes of diversifying selection during the divergence of the surveyed species. Present estimates of gene turnover and coding sequence substitution rates show that this family is evolving faster than any known Drosophila chemosensory family. To date, only other insect gustatory-related genes among these families had shown evolutionary dynamics close to those observed in CheBs. Our findings reveal the high adaptive potential of molecular components of the gustatory system in insects and anticipate a key role of genes involved in this sensory modality in species adaptation and diversification
Introduction
No full textThe book aims to explore the legal, social, and ethical dimensions of disability within the context of family relationships, offering a comprehensive analysis of how the rights and obligations of individuals with disabilities are protected, promoted, and challenged in contemporary societies. To this end, the book brings together contributions from numerous legal scholars from different universities worldwide on the topic. The various chapters entrusted to them not only offer independently appreciable research reflections but also contribute as a whole to investigate, in a synergistic and complementary way, the overall issue related to the legal status of persons with disabilities from different disciplinary perspectives, both legal and extra-legal, placing it in a strongly international and interdisciplinary framework
Sermon, y oracion panegirica, predicada... por el Licenciado Sebastian de Herrera y Rozas...
No full textInic. grab.Enc. Perg.Sign.: A-C
Genòmica evolutiva de la via de transducció de senyal de la insulina/TOR a insectes i vertebrats.
No full text[cat] Els gens estan sotmesos a forces selectives diferents. Un dels objectius de la Biologia Evolutiva és entendre els factors que determinen aquestes diferències. Els gens rarament actuen de manera aïllada, sinó que normalment funcionen com a elements de xarxes complexes formades per un gran nombre de molècules que interactuen entre si. Tot i la rellevància d’aquestes xarxes per entendre l’evolució dels gens, les propietats evolutives d’aquestes xarxes són encara poc conegudes. En aquesta tesi hem estudiat les forces selectives (selecció positiva i negativa) que han actuat sobre els gens implicats en la via de la insulina/TOR, i hem relacionat aquestes forces amb la posició dels gens a la via. Aquest estudi s’ha realitzat en 12 espècies del gènere Drosophila (primer article de la tesi), i en 6 espècies de vertebrats (humà, ratolí, vaca, opòssum, ornitorinc i pollastre) (segon article). A aquests efectes, s’han identificat i anotat els gens implicats a la via en totes les espècies estudiades, s’ha reconstruït la seva història evolutiva mitjançant tècniques d’anàlisi filogenètica, i s’han caracteritzat les forces evolutives que hi han actuat a partir de la relació la divergència no sinònima (dN) i sinònima (dS), ω = dN/dS.
Totes les famílies gèniques estudiades tenen almenys un representant a totes les espècies estudiades. A més, tots els gens estudiats estan sotmesos a selecció purificadora, la qual cosa indica que aquests gens són funcionals. Per tant, tots els organismes estudiats presenten una via de la insulina/TOR completa i funcional.
Tant a Drosophila com a vertebrats, observem que el nivell de limitació funcional (o selecció purificadora) sota el que evolucionen els gens es correlaciona amb la posició dels gens a la via (mesurada com el nombre de passos des del receptor de la insulina –posició 0– fins la resta de components –posicions 1 a 10), essent els gens de la part downstream els que evolucionen sota un major grau de limitació funcional. El sentit d’aquesta correlació és contrari al que s’ha trobat generalment en rutes metabòliques, on són els gens de la part upstream es que estan sotmesos a un major grau de limitació funcional. Vam avaluar l’impacte d’una sèrie de factors que es correlacionen amb ω (selecció positiva, nivell d’expressió gènica, nombre de teixits en què un gen s’expressa, grau d’esbiaix en l’ús de codons, longitud de les proteïnes codificades, i connectivitat en la xarxa d’interaccions proteïna-proteïna) sobre aquesta correlació. Aquesta anàlisi demostra que la correlació entre la posició a la via i els graus de limitació funcional és independent d’aquests factors. A més, observem que els gens que codifiquen proteïnes que interactuen físicament evolucionen sota seleccions selectives semblants, la qual cosa indica que aquestes proteïnes co-evolucionen.
En global, aquests resultats indiquen clarament que els nivells de limitació funcional als què estan sotmesos els gens de la via de la insulina/TOR depenen de la posició que les proteïnes codificades ocupen a la via. Per tant, l’arquitectura de la via té un impacte sobre l’evolució dels seus gens.[eng] Genes are subject to disparate evolutionary forces. One of the goals in Evolutionary Biology is to understand the factors underlying these differences. Genes rarely act in isolation, but they rather operate as elements of complex networks of interacting molecules. Despite the relevance of these networks for understanding gene evolution, the evolutionary properties of these networks remain poorly understood. In this thesis we have studied evolutionary forces (positive and negative selection) that acted on genes involved in the insulin/TOR pathway, and we have related these forces to the position that genes occupy in the pathway. This study has been performed in 12 species of the genus Drosophila, and in 6 vertebrate species. For that purpose, we have (1) identified and annotated the genes involved in this pathway in these species; (2) reconstructed their evolutionary history using phylogenetic analysis; and (3) characterized evolutionary forces that have acted on these genes from the nonsynonymous (dN) to synonymous (dS) divergence ratio (ω = dN/dS).
All the studied gene families have at least one representative in all studied species. Furthermore, all studied genes evolve under purifying selection, indicating that they are functional. Therefore, all studied organisms have a complete and functional insulin/TOR pathway.
In both Drosophila and vertebrates, we observed that the strength of purifying selection acting on genes correlates with their positions in the pathway, with downstream genes evolving under stronger selective constraint. We evaluated the impact of a number of factors (positive selection, gene expression level and breadth, codon bias, protein length, and connectivity in the protein-protein interaction network) on the observed correlation. This analysis shows that the correlation between pathway position and the strength of purifying selection is independent of these factors. Furthermore, we observed that genes encoding proteins that physically interact evolve under similar selective pressures, which indicates that these proteins co-evolve.
Taken together, these results clearly indicate that levels of selective constraint acting on genes of the insulin/TOR pathway are affected by the position that their encoded products occupy in the pathway. Therefore, the structure of the pathway has an effect on the patterns of molecular evolution of its components
Fit-For-Purpose Method Development to Determine Co-Occurring Multiclass Mycotoxins in Apple and Apple Puree Samples
No full textDue to the impact of the climate change on mycotoxins production and their occurrence in foods, it is important to consider the potential accumulation of unexpected mycotoxins in matrices susceptible to be contaminated such as apples. In this regard, a fit-for-purpose LC–MS/MS method to determine co-occurring mycotoxins in apple purees has been proposed, considering the fungal profile isolated from stored apple fruits. Due to the isolation of Fusarium spp., fumonisins were included in the method along with Alternaria toxins (alternariol, alternariol monomethyl ether, and tentoxin), aflatoxins, and the only so far regulated patulin. The method was fully characterized in terms of linearity, sensitivity (LODs and LOQs below 0.4 and 1.4 μg kg−1, respectively, except for patulin being lower than 1.2 and 4.1 μg kg−1), precision, and recovery. The optimized method was then applied to the analysis of stored apples and apple purees from retail market. The preliminary survey brought the first evidence of FB1 occurrence in apple purees and highlighted the need for monitoring mycotoxins co-occurrence in apples and apple-based products
Apple mycotoxins: From orchard to processed apple puree
No full textApples and apple-derived products can be contaminated with patulin and, to a lesser extent, aflatoxin B1 and fumonisins. Fruits were collected from Golden Delicious and Imperatore trees in three orchards in Veneto, Northern Italy, and analysed for the presence of fungi and mycotoxins. Sampling and analyses were also carried out from storage bins to final puree tanks along the apple-puree production chain. Alternaria spp. and Penicillium spp. were commonly isolated from apples collected in the field, but their presence varied with cultivar and orchard location. In contrast, Aspergillus section Flavi spp. and Fusarium spp. were only detected via direct isolation from chopped fruits. Patulin and Alternaria toxins were frequently identified in fresh fruits, while aflatoxins were also present in some fruits albeit at very low levels. Fungi were present in fruits entering the apple-puree production line, but not in apple puree after treatment at 95–105 °C. In contrast, the abovementioned mycotoxins were detected at all stages along the production line. Surprisingly, fumonisins were only detected after the apple puree was subjected to thermal treatment. Implications of these findings were discussed and few unresolved scientific questions were posed to stimulate further lines of study
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