The two-phase formation history of spiral galaxies traced by the cosmic evolution of the bar fraction

We study the evolution of galactic bars and the link with disk and spheroid formation in a sample of zoom-in cosmological simulations. Our simulation sample focuses on galaxies with present-day stellar masses in the 10^10-10^11 Msun range, in field and loose group environments, with a broad variety of mass growth histories. In our models, bars are almost absent from the progenitors of present-day spirals at z>1.5, and they remain rare and generally too weak to be observable down to z~1. After this characteristic epoch, the fractions of observable and strong bars raise rapidly, bars being present in 80% of spiral galaxies and easily observable in two thirds of these at z<0.5. This is quantitatively consistent with the redshift evolution of the observed bar fraction. Our models predict that the decrease in the bar fraction with increasing redshift should continue with a fraction of observable bars <10-15% in disk galaxies at z>1. Our models also predict later bar formation in lower-mass galaxies, in agreement with existing data. We find that the characteristic epoch of bar formation, namely redshift z~0.8-1, corresponds to the epoch at which today's spirals acquire their disk-dominated morphology. At higher redshift, disks tend to be rapidly destroyed by mergers and gravitational instabilities and rarely develop significant bars. The bar formation epoch corresponds to the transition between an early "violent" phase of spiral galaxy formation at z>1 and a late "secular" phase at z<0.8. In the secular phase, the presence of bars substantially contributes to the growth of the bulge, but the bulge mass budget remains statistically dominated by the contribution of mergers, interactions and disk instabilities at high redshift. Early bars at z>1 are often short-lived, while most of the bars formed at z<1 persist down to z=0, late cosmological gas infall being necessary to maintain some of them.Comment: 15 pages, 15 figures, ApJ accepte

40S hnRNP particles are a novel class of nuclear biomolecular condensates.

Heterogenous nuclear ribonucleoproteins (hnRNPs) are abundant proteins implicated in various steps of RNA processing that assemble on nuclear RNA into larger complexes termed 40S hnRNP particles. Despite their initial discovery 55 years ago, our understanding of these intriguing macromolecular assemblies remains limited. Here, we report the biochemical purification of native 40S hnRNP particles and the determination of their complete protein composition by label-free quantitative mass spectrometry, identifying A-group and C-group hnRNPs as the major protein constituents. Isolated 40S hnRNP particles dissociate upon RNA digestion and can be reconstituted in vitro on defined RNAs in the presence of the individual protein components, demonstrating a scaffolding role for RNA in nucleating particle formation. Finally, we revealed their nanometer scale, condensate-like nature, promoted by intrinsically disordered regions of A-group hnRNPs. Collectively, we identify nuclear 40S hnRNP particles as novel dynamic biomolecular condensates

Expression of zebrafish pax6b in pancreas is regulated by two enhancers containing highly conserved cis-elements bound by PDX1, PBX and PREP factors

BACKGROUND: PAX6 is a transcription factor playing a crucial role in the development of the eye and in the differentiation of the pancreatic endocrine cells as well as of enteroendocrine cells. Studies on the mouse Pax6 gene have shown that sequences upstream from the P0 promoter are required for expression in the lens and the pancreas; but there remain discrepancies regarding the precise location of the pancreatic regulatory elements. RESULTS: Due to genome duplication in the evolution of ray-finned fishes, zebrafish has two pax6 genes, pax6a and pax6b. While both zebrafish pax6 genes are expressed in the developing eye and nervous system, only pax6b is expressed in the endocrine cells of the pancreas. To investigate the cause of this differential expression, we used a combination of in silico, in vivo and in vitro approaches. We show that the pax6b P0 promoter targets expression to endocrine pancreatic cells and also to enteroendocrine cells, retinal neurons and the telencephalon of transgenic zebrafish. Deletion analyses indicate that strong pancreatic expression of the pax6b gene relies on the combined action of two conserved regulatory enhancers, called regions A and C. By means of gel shift assays, we detected binding of the homeoproteins PDX1, PBX and PREP to several cis-elements of these regions. In constrast, regions A and C of the zebrafish pax6a gene are not active in the pancreas, this difference being attributable to sequence divergences within two cis-elements binding the pancreatic homeoprotein PDX1. CONCLUSION: Our data indicate a conserved role of enhancers A and C in the pancreatic expression of pax6b and emphasize the importance of the homeoproteins PBX and PREP cooperating with PDX1, in activating pax6b expression in endocrine pancreatic cells. This study also provides a striking example of how adaptative evolution of gene regulatory sequences upon gene duplication progressively leads to subfunctionalization of the paralogous gene pair

Towards enhanced adoption of soil-improving management practices in Europe

17 páginas, 1 tabla, 4 figurasSustainable agricultural soil management practices are key to restore, maintain and improve soil health. The European Joint Programme for SOIL (EJP SOIL) has identified twelve main soil challenges in Europe. To assess the potential and eventually increase the adoption of soil-improving management practices, it is necessary to know (i) the current levels of adoption of the practices, (ii) socio-technical barriers influencing their adoption, and (iii) their bio-physical limits. This study compiled an inventory of soil-improving management practices relevant to European conditions, and used a survey among soil scientists to assess the levels of adoption of these practices in Europe. In total, 53 soil management practices were identified that address one or several of the soil challenges. The adoption of most practices was low or spatially heterogeneous across Europe, highlighting region-specific limitations to sustainable soil management. Qualitative interviews were conducted to explore the importance of socio-technical aspects of adoption. Using conservation agriculture as an example, factors that can hinder adoption included the availability of knowledge and adequate machinery, financial risks, and farming traditions. Through a modelling approach, 54% of arable land in Europe was found to be suitable for cover cropping, indicating that the adoption of soil management practices is frequently limited by climatic constraints. We propose a region-specific approach that recognizes the importance of identifying and overcoming socio-technical barriers, and by acknowledging bio-physical limits that may be expanded by innovation.This work was funded under the European Joint Program for SOIL (EJP SOIL), which has received funding from the European Union's Horizon 2020 research and innovation programme: Grant agreement No 862695.Open access funding provided by Agroscope.Peer reviewe

Measurement of nuclear modification factors of gamma(1S)), gamma(2S), and gamma(3S) mesons in PbPb collisions at root s(NN)=5.02 TeV

The cross sections for ϒ(1S), ϒ(2S), and ϒ(3S) production in lead-lead (PbPb) and proton-proton (pp) collisions at √sNN = 5.02 TeV have been measured using the CMS detector at the LHC. The nuclear modification factors, RAA, derived from the PbPb-to-pp ratio of yields for each state, are studied as functions of meson rapidity and transverse momentum, as well as PbPb collision centrality. The yields of all three states are found to be significantly suppressed, and compatible with a sequential ordering of the suppression, RAA(ϒ(1S)) > RAA(ϒ(2S)) > RAA(ϒ(3S)). The suppression of ϒ(1S) is larger than that seen at √sNN = 2.76 TeV, although the two are compatible within uncertainties. The upper limit on the RAA of ϒ(3S) integrated over pT, rapidity and centrality is 0.096 at 95% confidence level, which is the strongest suppression observed for a quarkonium state in heavy ion collisions to date. © 2019 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). Funded by SCOAP3.Peer reviewe

Electroweak production of two jets in association with a Z boson in proton-proton collisions root s =13 TeV

A measurement of the electroweak (EW) production of two jets in association with a Z boson in proton-proton collisions at root s = 13 TeV is presented, based on data recorded in 2016 by the CMS experiment at the LHC corresponding to an integrated luminosity of 35.9 fb(-1). The measurement is performed in the lljj final state with l including electrons and muons, and the jets j corresponding to the quarks produced in the hard interaction. The measured cross section in a kinematic region defined by invariant masses m(ll) > 50 GeV, m(jj) > 120 GeV, and transverse momenta P-Tj > 25 GeV is sigma(EW) (lljj) = 534 +/- 20 (stat) fb (syst) fb, in agreement with leading-order standard model predictions. The final state is also used to perform a search for anomalous trilinear gauge couplings. No evidence is found and limits on anomalous trilinear gauge couplings associated with dimension-six operators are given in the framework of an effective field theory. The corresponding 95% confidence level intervals are -2.6 <cwww/Lambda(2) <2.6 TeV-2 and -8.4 <cw/Lambda(2) <10.1 TeV-2. The additional jet activity of events in a signal-enriched region is also studied, and the measurements are in agreement with predictions.Peer reviewe

The GEOTRACES Intermediate Data Product 2014

The GEOTRACES Intermediate Data Product 2014 (IDP2014) is the first publicly available data product of the international GEOTRACES programme, and contains data measured and quality controlled before the end of 2013. It consists of two parts: (1) a compilation of digital data for more than 200 trace elements and isotopes (TEIs) as well as classical hydrographic parameters, and (2) the eGEOTRACES Electronic Atlas providing a strongly inter-linked on-line atlas including more than 300 section plots and 90 animated 3D scenes. The IDP2014 covers the Atlantic, Arctic, and Indian oceans, exhibiting highest data density in the Atlantic. The TEI data in the IDP2014 are quality controlled by careful assessment of intercalibration results and multi-laboratory data comparisons at cross-over stations. The digital data are provided in several formats, including ASCII spreadsheet, Excel spreadsheet, netCDF, and Ocean Data View collection. In addition to the actual data values the IDP2014 also contains data quality flags and 1-? data error values where available. Quality flags and error values are useful for data filtering. Metadata about data originators, analytical methods and original publications related to the data are linked to the data in an easily accessible way. The eGEOTRACES Electronic Atlas is the visual representation of the IDP2014 data providing section plots and a new kind of animated 3D scenes. The basin-wide 3D scenes allow for viewing of data from many cruises at the same time, thereby providing quick overviews of large-scale tracer distributions. In addition, the 3D scenes provide geographical and bathymetric context that is crucial for the interpretation and assessment of observed tracer plumes, as well as for making inferences about controlling processes

Cenni sull'uso della ceramica nel Belgio settentrionale protostorico attraverso le analisi dei residui presenti nella matrice ceramica

Interest for paleo-diets has grown in parallel with the development of technologies and analytical tools that have now made it possible to identify organic residues more and more precisely. In this paper we present the first analytical results of a first batch of eight pottery fragments recovered from the Late Bronze/Early Iron Age site (Hallstatt B-C-D) of Linsmeau in Belgium. The study of ceramics for this period has traditionally served to define cultural groups and to provide dates, their function deduced from their shape and sometimes from cooking caramels preserved inside the pots. New methods, such as proteomics and metabolomics, are now available to extract a wider range of information from these same vases without having to rely on visual clues, but they also have to be planned for upstream. These new methods and instruments were used in our case. After a thorough dry cleaning, twin samples of powdered pottery wall were taken from each fragment using a clean dentist drill and sealed in aluminium foil. The analyzes of organic residues from Linsmeau's 'La Closiere' abundant pottery will provide insight into food, culinary and funerary practices encompassing a period between the Late Bronze Age and the end of the Early Iron Age. Sadly, this way of research still remains rarely explored, a gap that this study attempts to begin to address.L’intérêt pour les paléo-diètes a cru en parallèle avec le perfectionnement des technologies et des outils d’analyses qui ont permis d’identifier les résidus organiques de manière de plus en plus précise. Dans ce rapport nous présentons les premiers résultats d'analyse d'un premier lot de huit fragments de poterie retrouvés sur le site du Bronze Final/Premier âge du Fer (Hallstatt B-C-D) de Linsmeau 'La Closiere' en Belgique. L'étude de la céramique pour cette période a traditionnellement servi à définir des groupes culturels et fournir des datations, leur fonction déduite de leur forme et parfois de caramels de cuissons préservés à l’intérieur des vases.Aujourd’hui de nouvelles méthodes : protéomique, métabolomique, sont disponibles pour extraire une plus large gamme d’informations de ces mêmes vases. Ces nouvelles méthodes et instruments ont été utilisés ici. Les analyses des résidus organiques de l’abondante céramique de Linsmeau permettront de fournir un aperçu des pratiques alimentaires et culinaires entre l’âge du Bronze final et le premier âge du Fer. Malgré tout, jusqu’à présent, cette voie de recherche reste peu explorée, une lacune que cette étude tente d’adresser.L'interesse per le paleo-diete è cresciuto parallelamente allo sviluppo di tecnologie e strumenti analitici che hanno permesso oggi di identificare i residui organici in modo sempre più preciso. In questo lavoro presentiamo i primi risultati analitici di un primo lotto di otto cocci di ceramiche rivenuti dal sito del Tardo Bronzo/Prima Età del Ferro (Hallstatt B-C-D) di Linsmeau 'la Closiere' in Belgio. Lo studio della ceramica per questo periodo è servito tradizionalmente a definire gruppi culturali ed a fornire datazioni, la loro funzione era dedotta dalla loro forma e talvolta di caramelle di cottura conservate all'interno dei vasi. Sono ora disponibili nuovi metodi, come la proteomica e la metabolomica per estrarre una gamma più ampia d'informazioni da questi stessi vasi, senza dover fare affidamento agli indizi visivi, ma questi studi devono anche essere pianificati a monte. Questi nuovi metodi e strumenti sono stati utilizzati nel nostro caso. Dopo un'accurata pulitura a secco, da ogni frammento sono stati prelevati campioni doppi di polvere della parete della ceramica utilizzando un trapano da dentista pulito e sigillati in un foglio di alluminio. Le analisi dei residui organici dell'abbondante ceramica "La Closiere" di Linsmeau forniranno informazioni sulle pratiche alimentari, culinarie e funerarie che coprono un periodo compreso tra la tarda età del Bronzo e la fine della prima età del Ferro. Purtroppo, questo modo di ricerca rimane ancora poco esplorato, una lacuna che questo studio tenta di iniziare a colmare

Linsmeau in the Late Bronze Age : pottery for eating, pottery for drinking: Metabolomic analysis of ceramics from the Late Bronze / Early Iron Age site of Linsmeau

Metabolomic analysis of ceramics from the Late Bronze / Early Iron Age site of Linsmeau. In 2022 we conducted a serie of pot restorations of ceramics coming from pits in Linsmeau, Belgium. The pots that were selected were pots that had a good portion of the vase intact. One pot with handle and some large rough potsherds came from one shallow pit, another vase with handle came from a grain storage pit, one deep plate came from another probable grain storage pit, and finally two vases came from a probable hallstatt B2 cremation burial and finally, a miniature parasol cup came from another grin storage pit fill