Examination of the Feynman-Hibbs Approach in the Study of NeN_N-Coronene Clusters at Low Temperatures

Feynman-Hibbs (FH) effective potentials constitute an appealing approach for investigations of many-body systems at thermal equilibrium since they allow us to easily include quantum corrections within standard classical simulations. In this work we apply the FH formulation to the study of Ne$_N$-coronene clusters ($N=$ 1-4, 14) in the 2-14 K temperature range. Quadratic (FH2) and quartic (FH4) contributions to the effective potentials are built upon Ne-Ne and Ne-coronene analytical potentials. In particular, a new corrected expression for the FH4 effective potential is reported. FH2 and FH4 cluster energies and structures -obtained from energy optimization through a basin-hoping algorithm as well as classical Monte Carlo simulations- are reported and compared with reference path integral Monte Carlo calculations. For temperatures $T> 4$ K, both FH2 and FH4 potentials are able to correct the purely classical calculations in a consistent way. However, the FH approach fails at lower temperatures, especially the quartic correction. It is thus crucial to assess the range of applicability of this formulation and, in particular, to apply the FH4 potentials with great caution. A simple model of $N$ isotropic harmonic oscillators allows us to propose a means of estimating the cut-off temperature for the validity of the method, which is found to increase with the number of atoms adsorbed on the coronene molecule

¿Qué sabemos de los peces óseos marinos del neógeno en Chile? Diversidad e implicaciones biogeográficas

Durante el Neógeno ocurren intensos eventos, oceanográficos y climáticos, que influyeron sobre la fauna marina de Chile desde el pasado hasta la actualidad. Estudios enfocados en la evaluación del efecto de estos eventos sobre la diversidad de mamíferos, aves y tiburones han sido previamente abordados. Sin embargo, las interacciones de estos eventos con los peces óseos como grupo de estudio no han sido analizados en detalle. Este trabajo compara la diversidad de peces óseos del Neógeno con la actualidad y da a conocer lo que sabemos de su diversidad. Se procesaron los datos disponibles de la presencia de peces óseos marinos en formaciones neógenas de Chile y la actualidad. Se comparó la composición del registro fósil de peces neógenos con el registro de peces actuales a 3 niveles taxonómicos distintos (familia, género y especie). Finalmente, se analizaron los rangos de distribución de los taxa fósiles que sobrevivieron con el objetivo de realizar aproximaciones de las dinámicas paleobiogeográficas. Nuestros resultados muestran que la diversidad actual de peces óseos marinos en Chile es de 624 géneros (1.196 especies), mientras que para el Neógeno se han reportado 65 géneros (46 especies). Comparado con la diversidad actual, el registro fósil de peces es representado por un 3,9% a nivel de especie, 10,4% a nivel de género y 23,4% a nivel de familias, lo que puede ser relacionado con la baja cantidad de estudios enfocados en fósiles de este grupo. Del total de 46 especies fósiles reportadas, sólo una se encuentra actualmente presente en las costas de Chile. A nivel genérico, un 38,5% se encuentra actualmente ausente en la región y un 61,5% sobrevive. En relación a los géneros ausentes actualmente, un 20% corresponde a extinción global y un 80% a extinción regional. Estos cambios en las dinámicas biogeográficas de peces óseos del pasado al reciente, podrían estar relacionadas con los intensos eventos climáticos y oceanográficos que han ocurrido en los últimos 23 millones de años. Los análisis de rarefacción y de extrapolación de especies confirman que a pesar de que han aumentado los trabajos sobre peces óseos en los últimos años, todavía se podrían encontrar un mayor número de taxa si se aplica un mayor esfuerzo de muestreo. Estudios futuros podrían ayudarnos a comprender de mejor manera el efecto de los cambios climáticos y oceanográficos sobre los peces del Neógeno de Chile.Durant el Neogen ocorren intensos esdeveniments, oceanogràfics, i climàtics, que van influir sobre la fauna marina de Xile des del passat fins a l’actualitat. Estudis enfocats en l’avaluació de l’efecte d’aquests esdeveniments sobre la diversitat de mamífers, ocells i taurons han sigut prèviament abordats. No obstant això, les interaccions d’aquests esdeveniments amb els peixos ossis com a grup d’estudi no han sigut analitzats detalladament. Aquest treball analitza la diversitat de peixos ossis del Neogen comparat amb l’actualitat i dona a conéixer que sabem de la seua diversitat. Es van analizar les dades disponibles de la presència de peixos ossis marins en formacions neógenas de Xile i l’actualitat. Es va comparar la composició del registre fòssil de peixos neògens amb el registre de peixos actuals a 3 nivells taxonòmics diferents (família, gènere i espècie). Finalment, es van analizar els rangs de distribució dels taxa fòssils que van sobreviure amb la finalitat de realitzar aproximacions de les dinàmiques paleobiogeográficas. Els nostres resultats mostren que la diversitat actual de peixos ossis marins a Xile és de 624 gèneres (1.196 espècies), mentre que per al Neogen s’han reportat 65 gèneres (46 espècies). Comparat amb la diversitat actual, el registre fòssil de peixos és representat per un 3,9% a nivell d’espècie, 10,4% a nivell de gènere i 23,4% a nivell de famílies, la qual cosa pot ser relacionat amb la baixa quantitat d’estudis enfocats en fòssils d’aquest grup. Del total de 46 espècies fòssils reportades, només un 4% es troba actualment present en les costes de Xile. A nivell genèric, un 38.5% es troba actualment absent a la regió i un 61.5% sobreviu. En relació als gèneres absents actualment, un 20% correspon a extinció global i un 80% a extinció regional. Aquests canvis en les dinàmiques biogeogràfiques de peixos ossis del passat al recent, podrien estar relacionades amb els intensos esdeveniments climàtics i oceanogràfics que han ocorregut en els últims 23 milions d’anys. Les anàlisis de rarefacció i d’extrapolació d’espècies confirmen que a pesar que han augmentat els treballs sobre el grup en els últims anys, encara es podrien trobar un major número de taxa si s’aplica un major esforç de mostreig. Estudis futurs podrien ajudar-nos a comprendre de millor manera l’efecte dels canvis climàtics i oceanogràfics sobre els peixos del Neogen de Xile.During the Neogene occurred intense oceanographic and climatic events which had an effect on the marine fauna from the past to the present. Studies focused on the evaluation of the effect of these events on the diversity of mammals, birds and sharks have been previously addressed. However, the interactions of these events with bony fishes as a study group have not been analyzed in detail. This work analyzes the diversity of bony fishes from the Neogene compared to today and reveals what we know about their diversity. We analyzed the available data on the presence of marine bony fishes from Neogene formations in Chile and today. The composition of the fossil record of Neogene fishes was compared to the current fish record at 3 different taxonomic levels (family, genus, and species). Lastly, the distribution ranges of the surviving fossil taxa were analyzed in order to make approximations of the paleobiogeographic dynamics. Our results show that the current diversity of marine bony fish in Chile is composed of 624 genera (1,196 species), whereas from the Neogene 65 genera (46 species) have been reported. Compared to the current diversity, the fossil record of fishes is represented by 3.9% at the species level, 10.4% at the genus level and 23.4% at the family level, which can be related to the low number of studies focused on fossils of this group. Of the total of 46 fossil species reported, only 4% is currently present along the coast of Chile. At a generic level, 38.5% are currently absent in the region whereas 61.5% survived. In relation to the genera currently absent in the region, 20% are globally extinct and 80% regional extinct. These changes in the biogeographic dynamics of bony fishes from the past to the recent could be related to the intense climatic and oceanographic events that have occurred in the last 23 million years. The rarefaction and extrapolation analyses confirm that although the studies focused on the group have increased in the last years, a higher number of taxa could still be found if the sampling effort is increased. Future studies could help us to a better understanding of the effects of climatic and oceanographic changes on the group during the Neogene of Chile

Las emociones en los procesos pedagógicos y artísticos

Este cuarto volumen de la Colección Emociones e Interdisciplina orienta la mirada hacia dos dimensiones centrales, en las cuales la afectividad se analiza tanto a partir de los procesos pedagógicos, como del arte y del registro de lo estético. Esta mirada se adentra en el estudio del sujeto que siente, piensa y reflexiona y es justo, a partir de este punto, donde es posible acotar, teórica y metodológicamente, las emociones y sus expresiones como objeto de estudio sociológico.ITESO. A.C

Dung removal increases under higher dung beetle functional diversity regardless of grazing intensification

Dung removal by macrofauna such as dung beetles is an important process for nutrient cycling in pasturelands. Intensification of farming practices generally reduces species and functional diversity of terrestrial invertebrates, which may negatively affect ecosystem services. Here, we investigate the effects of cattle-grazing intensification on dung removal by dung beetles in field experiments replicated in 38 pastures around the world. Within each study site, we measured dung removal in pastures managed with low- and high-intensity regimes to assess between-regime differences in dung beetle diversity and dung removal, whilst also considering climate and regional variations. The impacts of intensification were heterogeneous, either diminishing or increasing dung beetle species richness, functional diversity, and dung removal rates. The effects of beetle diversity on dung removal were more variable across sites than within sites. Dung removal increased with species richness across sites, while functional diversity consistently enhanced dung removal within sites, independently of cattle grazing intensity or climate. Our findings indicate that, despite intensified cattle stocking rates, ecosystem services related to decomposition and nutrient cycling can be maintained when a functionally diverse dung beetle community inhabits the human-modified landscape

Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2

The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality

Genome-wide meta-analysis for Alzheimer's disease cerebrospinal fluid biomarkers

Amyloid-beta 42 (A beta 42) and phosphorylated tau (pTau) levels in cerebrospinal fluid (CSF) reflect core features of the pathogenesis of Alzheimer's disease (AD) more directly than clinical diagnosis. Initiated by the European Alzheimer & Dementia Biobank (EADB), the largest collaborative effort on genetics underlying CSF biomarkers was established, including 31 cohorts with a total of 13,116 individuals (discovery n = 8074; replication n = 5042 individuals). Besides the APOE locus, novel associations with two other well-established AD risk loci were observed; CR1 was shown a locus for A beta 42 and BIN1 for pTau. GMNC and C16orf95 were further identified as loci for pTau, of which the latter is novel. Clustering methods exploring the influence of all known AD risk loci on the CSF protein levels, revealed 4 biological categories suggesting multiple A beta 42 and pTau related biological pathways involved in the etiology of AD. In functional follow-up analyses, GMNC and C16orf95 both associated with lateral ventricular volume, implying an overlap in genetic etiology for tau levels and brain ventricular volume.Peer reviewe