Personajes mitológicos en la literatura europea del siglo XX: Casandra

El presente trabajo se centra en el personaje mitológico de Casandra e investiga el porqué de su empleo en la literatura del siglo XX, tomando como referente la Casandra de Christa Wolf, publicada en Alemania en 1983, y la Casandra de Benito Pérez Galdós que vio la luz en 1903 como novela dialogada y como obra dramática en 1910. Antes de llegar a estas obras hago un análisis de la figura de Casandra en las tragedias de Esquilo y de Eurípides y en la obra medieval Auto de la sibila Casandra de Gil Vicente, que he incluido como hito relevante en cuanto que presenta una Casandra diferente a la del mito en muchos aspectos. En el análisis lo que pretendo es establecer algunas de las conexiones entre las Casandras actuales con las clásicas, ya que, aunque en todas las obras ellas aparecen interrelacionadas, en el siglo XX aparecen con nuevas características que se le añaden al mito o varias modificaciones. He intentado explicar asimismo por qué Casandra, siendo un personaje secundario de la guerra de Troya, ha llegado a nuestros días con tanta fuerza en obras de distintos géneros y de distinta intención. La primera conclusión a la que he llegado es que la figura de la princesa troyana suele usarse en épocas de cambios políticos y sociales y en épocas de tensión bélica, por lo que Casandra suele significar deseo de cambio. La segunda conclusión es que en las obras del siglo XX se busca que quien las lea simpatice con la protagonista para que adopte su postura; a ello ayuda que Casandra aparezca como un personaje revolucionario que lucha por la verdad y no por falsas creencias. En definitiva, poco queda de la Casandra casi silenciada en Homero, porque la Casandra que vive en la literatura de hoy en día no es una princesa, sino una persona valiente

Antimicrobial Activity and Physicochemical Characterization of Oregano, Thyme and Clove Leave Essential Oils, Nonencapsulated and Nanoencapsulated, Using Emulsification

Background and objective: Functional properties of essential oils are attributed to their components, many of which exhibit antimicrobial activity against pathogenic and spoilage microorganisms in a wide variety of foods. However, essential oils are unstable compounds; therefore, they can be encapsulated for a better protection and increase of functionality. In this work, antimicrobial activities of oregano, thyme and clove leave essential oils (non-encapsulated and nanoencapsulated) were assessed against Escherichia coli ATCC 29922, Salmonella typhimurium ATCC 14028 and Staphylococcus aureus ATCC 25923 using emulsification.Material and methods: The essential oils were characterized based on their physicochemical properties. Nanoemulsions were prepared, using 5% (w w-1) of essential oils, and then characterized based on their physical properties, stability and encapsulation efficiency. The microdilution antimicrobial assay was carried out to assess minimum inhibitory concentration and minimum bactericidal concentration of the essential oils and their nanoemulsions. Data from physical properties of the essential oils and physical properties, stability and encapsulation efficiency of the nanoemulsions were statistically analyzed.Results and conclusion: Antimicrobial activity of the essential oils showed decreases in minimum inhibitory concentration by 27-60% for the nanoencapsulated oils, compared to nonencapsulated oils. Nanoencapsulated and nonencapsulated oregano essential oils exhibited the lowest minimum inhibitory concentration and minimum bactericidal concentration values. Based on the results, nanoencapslulated essential oils may further be used in various foods to avoid microbial contaminations.Conflict of interest: The authors declare no conflict of interest

Gene expression differences in relation to age and social environment in queen and worker bumble bees

Eusocial insects provide special insights into the genetic pathways influencing aging because of their long-lived queens and flexible aging schedules. Using qRT-PCR in the primitively eusocial bumble bee Bombus terrestris (Linnaeus), we investigated expression levels of four candidate genes associated with taxonomically widespread age-related pathways (coenzyme Q biosynthesis protein 7, COQ7; DNA methyltransferase 3, Dnmt3; foraging, for; and vitellogenin, vg). In Experiment 1, we tested how expression changes with queen relative age and productivity. We found a significant age-related increase in COQ7 expression in queen ovary. In brain, all four genes showed higher expression with increasing female (queen plus worker) production, with this relationship strengthening as queen age increased, suggesting a link with the positive association of fecundity and longevity found in eusocial insect queens. In Experiment 2, we tested effects of relative age and social environment (worker removal) in foundress queens and effects of age and reproductive status in workers. In this experiment, workerless queens showed significantly higher for expression in brain, as predicted if downregulation of for is associated with the cessation of foraging by foundress queens following worker emergence. Workers showed a significant age-related increase in Dnmt3 expression in fat body, suggesting a novel association between aging and methylation in B. terrestris. Ovary activation was associated with significantly higher vg expression in fat body and, in younger workers, in brain, consistent with vitellogenin's ancestral role in regulating egg production. Overall, our findings reveal a mixture of novel and conserved features in age-related genetic pathways under primitive eusociality

Antioxidant effect of natural table olives phenolic extract against oxidative stress and membrane damage in enterocyte-like cells

The phenolic fraction of a naturally fermented cultivar of table olives, “Tonda di Cagliari,” was investigated for the ability to protect Caco-2 cells against oxidative stress and membrane damage induced by tert-butyl hydroperoxyde (TBH). TBH exposure resulted in an alteration of cellular redox status, with an increase in reactive oxygen species (ROS) and a decrease in reduced glutathione (GSH) level. A loss of the epithelial integrity, as indicated by the decrease of the transepithelial electrical resistance value, was also observed over time, together with an intense lipid peroxidation process. The olives phenolic extract significantly counteracted ROS generation and subsequent alteration of monolayer integrity and membrane oxidative damage. The protective action of the extract is likely due to the scavenging ability of its main components, as hydroxytyrosol, oleuropein, and verbascoside among the secoiridoids and derivatives. Since olives phenolic compounds concentrate in the intestinal lumen, they may be a useful tool in the prevention of intestinal disorders related to oxidative damage

Effect of ageing on CMV-specific CD8 T cells from CMV seropositive healthy donors

<p>Abstract</p> <p>Background</p> <p>Ageing is associated with changes in the immune system with substantial alterations in T-lymphocyte subsets. Cytomegalovirus (CMV) is one of the factors that affect functionality of T cells and the differentiation and large expansions of CMV pp65-specific T cells have been associated with impaired responses to other immune challenges. Moreover, the presence of clonal expansions of CMV-specific T cells may shrink the available repertoire for other antigens and contribute to the increased incidence of infectious diseases in the elderly. In this study, we analyse the effect of ageing on the phenotype and frequency of CMV pp65-specific CD8 T cell subsets according to the expression of CCR7, CD45RA, CD27, CD28, CD244 and CD85j.</p> <p>Results</p> <p>Peripheral blood from HLA-A2 healthy young, middle-aged and elderly donors was analysed by multiparametric flow cytometry using the HLA-A*0201/CMV pp65_495–504(NLVPMVATV) pentamer and mAbs specific for the molecules analysed. The frequency of CMV pp65-specific CD8 T cells was increased in the elderly compared with young and middle-aged donors. The proportion of naïve cells was reduced in the elderly, whereas an age-associated increase of the CCR7^nulleffector-memory subset, in particular those with a CD45RA^dimphenotype, was observed, both in the pentamer-positive and pentamer-negative CD8 T cells. The results also showed that most CMV pp65-specific CD8 T cells in elderly individuals were CD27/CD28 negative and expressed CD85j and CD244.</p> <p>Conclusion</p> <p>The finding that the phenotype of CMV pp65-specific CD8 T cells in elderly individuals is similar to the predominant phenotype of CD8 T cells as a whole, suggests that CMV persistent infections contributes to the age-related changes observed in the CD8 T cell compartment, and that chronic stimulation by other persistent antigens also play a role in T cell immunosenescence. Differences in subset distribution in elderly individuals showing a decrease in naive and an increase in effector-memory CD8 T cells may be relevant in the age-associated defective immune response.</p

Transcriptome-guided annotation and functional classification of long non-coding RNAs in Arabidopsis thaliana

Long non-coding RNAs (lncRNAs) are a prominent class of eukaryotic regulatory genes. Despite the numerous available transcriptomic datasets, the annotation of plant lncRNAs remains based on dated annotations that have been historically carried over. We present a substantially improved annotation of Arabidopsis thaliana lncRNAs, generated by integrating 224 transcriptomes in multiple tissues, conditions, and developmental stages. We annotate 6764 lncRNA genes, including 3772 that are novel. We characterize their tissue expression patterns and find 1425 lncRNAs are co-expressed with coding genes, with enriched functional categories such as chloroplast organization, photosynthesis, RNA regulation, transcription, and root development. This improved transcription-guided annotation constitutes a valuable resource for studying lncRNAs and the biological processes they may regulate

Bioassay-guided identification of the antiproliferative compounds of cissus trifoliata and the transcriptomic effect of resveratrol in prostate cancer pc3 cells

The bioassay-guided fractionation of a CHCl3-MeOH extract from the stems of Cissus trifo-liata identified an active fraction against PC3 prostate cancer cells. The treatment for 24 h showed an 80% reduction in cell viability (p ≤ 0.05) by a WST-1 assay at a concentration of 100 µg/mL. The HPLC-QTOF-MS analysis of the fraction showed the presence of coumaric and isoferulic acids, apigenin, kaempferol, chrysoeriol, naringenin, ursolic and betulinic acids, hexadecadienoic and octadecadienoic fatty acids, and the stilbene resveratrol. The exposure of PC3 cells to resveratrol (IC25 = 23 µg/mL) for 24 h induced significant changes in 847 genes (Z-score ≥ ±2). The functional classification tool of the DAVID v6.8 platform indicates that the underlying molecular mechanisms against the proliferation of PC3 cells were associated (p ≤ 0.05) with the process of differentiation and metabolism. These findings provide experimental evidence suggesting the potential of C. trifoliata as a promising natural source of anticancer compounds

Electrical impedance tomography as a tool for phenotyping plant roots

Background Plant roots are complex, three-dimensional structures that play a central role in anchorage, water and nutrient acquisition, storage and interaction with rhizosphere microbes. Studying the development of the plant root system architecture is inherently difficult as soil is not a transparent medium. Results This study uses electrical impedance tomography (EIT) to visualise oilseed rape root development in horticultural compost. The development of healthy, control plants and those infected with the gall-forming pathogen, Plasmodiophora brassicae—the causative agent of clubroot disease—were compared. EIT measurements were used to quantify the development of the root system and distinguish between control and infected plants at the onset of gall formation, approximately 20 days after inoculation. Although clear and stark differences between healthy and infected plants were obtained by careful (and hence laborious) packing of the growth medium in layers within the pots; clubroot identification is still possible without a laborious vessel filling protocol. Conclusions These results demonstrate the utility of EIT as a low-cost, non-invasive, non-destructive method for characterising root system architecture and plant-pathogen interactions in opaque growth media. As such it offers advantages over other root characterisation techniques and has the potential to act as a low-cost tool for plant phenotyping