La Sonata del Claro de Luna de Yannis Ritsos

Yannis Ritsos (1909-1990) es uno de los poetas más influyentes de la generación griega de 1930, análoga a la generación del ‘27 en España. Los poetas de esa generación trajeron el surrealismo a la poesía griega, y, algunos como Ritsos, un claro compromiso político, reflejado en su poesía. Su obra más conocida/traducida es de carácter políticamente comprometido, de tono seco y épico. La "Sonata del claro de luna", el poema aquí traducido, es de un lirismo marcadamente diferente, y es menos conocido, aunque sea de una belleza y recursos artísticos impactantes.Yannis Ritsos (1909-1990) is one of the most influential poets of the socalled 1930 generation of Greek poets (analogous to the 1927 one in Spain) who introduced surrealism in Greek poetry, and for some, such as Ritsos, a strong political engagement reflected in their poetry. His most read/translated work is imbued by a politically engaged, stark and epic tone. The poem translated/presented herewith is of a markedly different, lyrical character, and is less well-known, despite its arresting beauty and artistic elements

Histone Modifications as an Intersection Between Diet and Longevity

Histone modifications are key epigenetic regulators that control chromatin structure and gene transcription, thereby impacting on various important cellular phenotypes. Over the past decade, a growing number of studies have indicated that changes in various histone modifications have a significant influence on the aging process. Furthermore, it has been revealed that the abundance and localization of histone modifications are responsive to various environmental stimuli, such as diet, which can also affect gene expression and lifespan. This supports the notion that histone modifications can serve as a main cellular platform for signal integration. Hence, in this review we focus on the role of histone modifications during aging, report the data indicating that diet affects histone modification levels and explore the idea that histone modifications may function as an intersection through which diet regulates lifespan. A greater understanding of the epigenetic mechanisms that link environmental signals to longevity may provide new strategies for therapeutic intervention in age-related diseases and for promoting healthy aging

Agia Marina and Peristereònas: Two New Epipalaeolithic Sites on the Island of Lemnos (Greece)

The surveys carried out along the coasts of the Island of Lemnos (Greece) have led to the discovery of new Late Epipalaeolithic sites at Agia Marina and Peristereònas. Peristereònas yielded a knapped stone assemblage which is strictly comparable with that from Ouriakos, a site located along the south-eastern coast of the same island, while the artefacts from Agia Marina are more problematic to interpret, because they are probably to be attributed to a slightly different chronological period. However, the most characteristic artefacts recovered from the sites are represented by microlithic geometrics obtained by abrupt, bipolar or direct retouch, end scrapers, and different types of exhausted cores and technical pieces, which help us reconstruct the operative chain employed for the manufacture of the armatures. The scope of the paper is to contribute to the interpretation of the characteristics of the Late Epipalaeolithic assemblages discovered in the island, and to frame them into the general picture of the end of the Pleistocene period in this part of the Aegean. The artefacts from the sites show some unique characteristics, which do not find parallels in the knapped stone assemblages of the same period so far recovered along the coasts of the Aegean Sea, the eastern Mediterranean and the Levan

Cover Picture: Ann. Phys. 2'2018

In article number 1700256, Emanuele Verrelli and co‐workers propose that cluster beam deposition of sub‐2nm magic number Au clusters, Au20 and Au55, on flat surfaces reveals a rich evolution of the phenomena taking place at substrate level. New magic number clusters have been formed via coalescence of neighbouring clusters, such as Au561. Experimental and simulation results reveal that neighbouring clusters on the substrate coalesce only when the distance from their nearest neighbour cluster is below a critical mark of 0.5 nm

Microdosimetry of electrons in liquid water using the low-energy models of Geant4

The biological effects of ionizing radiation at the cellular level are frequently studied using the well-known formalism of microdosimetry, which provides a quantitative description of the stochastic aspects of energy deposition in irradiated media. Energy deposition can be simulated using Monte Carlo codes, some adopting a computationally efficient condensed-history approach, while others follow a more detailed track-structure approach. In this work, we present the simulation of microdosimetry spectra and related quantities (frequency-mean and dose-mean lineal energies) for incident monoenergetic electrons (50 eV-10 keV) in spheres of liquid water with dimensions comparable to the size of biological targets: base pairs (2 nm diameter), nucleosomes (10 nm), chromatin fibres (30 nm) and chromosomes (300 nm). Simulations are performed using the condensed-history low-energy physics models ( Livermore and Penelope ) and the track-structure Geant4-DNA physics models, available in the Geant4 Monte Carlo simulation toolkit. The spectra are compared and the influence of simulation parameters and different physics models, with emphasis on recent developments, is discussed, underlining the suitability of Geant4-DNA models for microdosimetry simulations. It is further shown that with an appropriate choice of simulation parameters, condensed-history transport may yield reasonable results for sphere sizes as small as a few tens of a nanometer

An implementation of discrete electron transport models for gold in the Geant4 simulation toolkit

Gold nanoparticle (GNP) boosted radiation therapy can enhance the biological effectiveness of radiation treatments by increasing the quantity of direct and indirect radiation-induced cellular damage. As the physical effects of GNP boosted radiotherapy occur across energy scales that descend down to 10 eV, Monte Carlo simulations require discrete physics models down to these very low energies in order to avoid underestimating the absorbed dose and secondary particle generation. Discrete physics models for electron transportation down to 10 eV have been implemented within the Geant4-DNA low energy extension of Geant4. Such models allow the investigation of GNP effects at the nanoscale. At low energies, the new models have better agreement with experimental data on the backscattering coefficient, and they show similar performance for transmission coefficient data as the Livermore and Penelope models already implemented in Geant4. These new models are applicable in simulations focussed towards estimating the relative biological effectiveness of radiation in GNP boosted radiotherapy applications with photon and electron radiation sources

Support Induced Effects on the Ir Nanoparticles Activity, Selectivity and Stability Performance under CO2 Reforming of Methane.

The production of syngas (H2 and CO)-a key building block for the manufacture of liquid energy carriers, ammonia and hydrogen-through the dry (CO2-) reforming of methane (DRM) continues to gain attention in heterogeneous catalysis, renewable energy technologies and sustainable economy. Here we report on the effects of the metal oxide support (γ-Al2O3, alumina-ceria-zirconia (ACZ) and ceria-zirconia (CZ)) on the low-temperature (ca. 500-750 ∘C) DRM activity, selectivity, resistance against carbon deposition and iridium nanoparticles sintering under oxidative thermal aging. A variety of characterization techniques were implemented to provide insight into the factors that determine iridium intrinsic DRM kinetics and stability, including metal-support interactions and physicochemical properties of materials. All Ir/γ-Al2O3, Ir/ACZ and Ir/CZ catalysts have stable DRM performance with time-on-stream, although supports with high oxygen storage capacity (ACZ and CZ) promoted CO2 conversion, yielding CO-enriched syngas. CZ-based supports endow Ir exceptional anti-sintering characteristics. The amount of carbon deposition was small in all catalysts, however decreasing as Ir/γ-Al2O3 > Ir/ACZ > Ir/CZ. The experimental findings are consistent with a bifunctional reaction mechanism involving participation of oxygen vacancies on the support's surface in CO2 activation and carbon removal, and overall suggest that CZ-supported Ir nanoparticles are promising catalysts for low-temperature dry reforming of methane (LT-DRM)

Simulation of DNA damage using the “molecularDNA” example application of Geant4-DNA

The scientific community has a large interest in the studies of DNA damage and response after exposure to ionizing radiation. Several in-silico methods have been proposed so far to model and study the mechanisms of DNA damage using Monte Carlo simulations. The “molecularDNA” example is one of the most recent applications to simulate the irradiation of human cancer cells and bacteria using Geant4-DNA. This example enables the simulation of the physical, physico-chemical and chemical stages of liquid water irradiation, including radiolytic processes following the particle irradiation of the pre-defined human cell geometries and it can be used to calculate the early direct and non-direct DNA damage such as single (SSB) and double strand breaks (DSB) as well as DNA fragment distribution. The application is user friendly and can be used following simple macro commands. The results of the Monte Carlo simulation are compared to experimental data of DSB yields, as well as with previously published simulation data.ICCBIKG 2023 : 2nd International Conference on Chemo and Bioinformatics, September 28-29, 2023; Kragujeva