Collective non-thermal emission from an extragalactic jet interacting with stars

The central regions of galaxies are complex environments, rich in evolved and/or massive stars. For galaxies hosting an active galactic nucleus (AGN) with jets, the interaction of the jets with the winds of the stars within can lead to particle acceleration, and to extended high-energy emitting regions. We compute the non-thermal emission produced by the jet flow shocked by stellar winds on the jet scale, far from the jet-star direct interaction region. First, prescriptions for the winds of the relevant stellar populations in different types of galaxies are obtained. The scenarios adopted include galaxies with their central regions dominated by old or young stellar populations, and with jets of different power. Then, we estimate the available energy to accelerate particles in the jet shock, and compute the transport and energy evolution of the accelerated electrons, plus their synchrotron and inverse Compton emission, in the shocked flow along the jet. A significant fraction of the jet energy, $\sim 0.1-10$\%, can potentially be available for the particles accelerated in jet-wind shocks in the studied cases. The non-thermal particles can produce most of the high-energy radiation on jet scales, far from the jet shock region. This high-energy emission will be strongly enhanced in jets aligned with the line of sight due to Doppler boosting effects. The interaction of relativistic jets with stellar winds may contribute significantly to the persistent high-energy emission in some AGNs with jets. However, in the particular case of M87, this component seems too low to explain the observed gamma-ray fluxes.Comment: 15 pages, 11 figures. Accepted to be published in A&

Analysis of the deterioration causes of maritime ports on the costa daurada

This project has been made to find out the factors that can end up causing the deterioration of a port. A port is a large and very expensive piece of engineering that is designed to last for many years as long as it is properly maintained. the project begins by explaining the general structure of which all ports are formed. Then, it introduces the necessary bases to do the project to of a seaport and the difficulties that this entails. Aside from the structural part, there are a series of characteristics of the area where the port is to be built that cannot be overlooked; since it is not the same to build a port on a coast where there are strong currents and bad weather, that to build it on a coast where there is a pleasant weather throughout the year. another important factor to take into account are the materials with which the port is built, since we should not forget that it is a structure that is submerged in the middle of the sea. This is important because the elements of the seawater react with the materials of the submerged structure of the port and there is a process of corrosion. This corrosion of the materials causes the structure to become weakened over the years. to give a practical example, there is a specific case of deterioration and half-sinking that happened in the port of coma-ruga explained at the end of the project.Objectius de Desenvolupament Sostenible::14 - Vida Submarin

On homology searches by protein Blast and the characterization of the age of genes

BACKGROUND: It has been shown in a variety of organisms, including mammals, that genes that appeared recently in evolution, for example orphan genes, evolve faster than older genes. Low functional constraints at the time of origin of novel genes may explain these results. However, this observation has been recently attributed to an artifact caused by the inability of Blast to detect the fastest genes in different eukaryotic genomes. Distinguishing between these two possible explanations would be of great importance for any studies dealing with the taxon distribution of proteins and the origin of novel genes. RESULTS: Here we used simulations of protein sequences to examine the capacity of Blast to detect proteins of diverse evolutionary rates in the different species of an eukaryotic phylogenetic tree that included metazoans, fungi and plants. We simulated the evolution of protein genes with the same evolutionary rates than those observed in functional mammalian genes and with among-site rate heterogeneity. Under these conditions, we found that only a very small percentage of simulated ancestral eukaryotic proteins was affected by the Blast artifact. We show that the good detectability of Blast is due to the heterogeneity of protein evolutionary rates at different sites, since only a small conserved motif in a sequence suffices to detect its homologues. Our results indicate that Blast, at least when applied within eukaryotes, only misses homologues of extremely fast-evolving sequences, which are rare in the mammalian genome, as well as sequences evolving homogeneously or pseudogenes. CONCLUSION: Although great care should be exercised in the recognition of remote homologues, most functional mammalian genes can be detected in eukaryotic genomes by Blast. That is, the majority of functional mammalian genes are not as fast as for not being detected in other metazoans, fungi or plants, if they had been present in these organisms. Thus, the correlation previously found between age and rate seems not to be due to a pure Blast artifact, at least for mammals. This may have important implications to understand the mechanisms by which novel genes originate

Uncertainty Quantification on Spent Nuclear Fuel with LMC

The recently developed method Lasso Monte Carlo (LMC) for uncertainty quantification is applied to the characterisation of spent nuclear fuel. The propagation of nuclear data uncertainties to the output of calculations is an often required procedure in nuclear computations. Commonly used methods such as Monte Carlo, linear error propagation, or surrogate modelling suffer from being computationally intensive, biased, or ill-suited for high-dimensional settings such as in the case of nuclear data. The LMC method combines multilevel Monte Carlo and machine learning to compute unbiased estimates of the uncertainty, at a lower computational cost than Monte Carlo, even in high-dimensional cases. Here LMC is applied to the calculations of decay heat, nuclide concentrations, and criticality of spent nuclear fuel placed in disposal canisters. The uncertainty quantification in this case is crucial to reduce the risks and costs of disposal of spent nuclear fuel. The results show that LMC is unbiased and has a higher accuracy than simple Monte Carlo.Comment: Conference paper from the 12th International Conference on Nuclear Criticality Safety (ICNC), Sendai, Japan, October 2023. Submitted to the Arxiv with the permission of the conference organiser

Mutation patterns of amino acid tandem repeats in the human proteome

BACKGROUND: Amino acid tandem repeats are found in nearly one-fifth of human proteins. Abnormal expansion of these regions is associated with several human disorders. To gain further insight into the mutational mechanisms that operate in this type of sequence, we have analyzed a large number of mutation variants derived from human expressed sequence tags (ESTs). RESULTS: We identified 137 polymorphic variants in 115 different amino acid tandem repeats. Of these, 77 contained amino acid substitutions and 60 contained gaps (expansions or contractions of the repeat unit). The analysis showed that at least about 21% of the repeats might be polymorphic in humans. We compared the mutations found in different types of amino acid repeats and in adjacent regions. Overall, repeats showed a five-fold increase in the number of gap mutations compared to adjacent regions, reflecting the action of slippage within the repetitive structures. Gap and substitution mutations were very differently distributed between different amino acid repeat types. Among repeats containing gap variants we identified several disease and candidate disease genes. CONCLUSION: This is the first report at a genome-wide scale of the types of mutations occurring in the amino acid repeat component of the human proteome. We show that the mutational dynamics of different amino acid repeat types are very diverse. We provide a list of loci with highly variable repeat structures, some of which may be potentially involved in disease

El catàleg sistemàtic ideat per Joan Oliva: el volum d'una obra inacabada

Durant un segle ha restat gairebé amagada una de les feines més importants, si no la que ho és més, que Joan Oliva i Milà va fer com a bibliotecari. Es tracta del catàleg sistemàtic de la Biblioteca Balaguer, format per gairebé set-cents sobres de paperetes i quinze volums per inscriure-les-hi. Una sèrie de contratemps va fer que els esforços esmerçats al llarg de trenta anys en aquest catàleg no donessin els fruits desitjats. En aquest article s’ordenen les peces d’un dels trencaclosques que conformen la història de la Biblioteca Museu