Evolution of long-lived globular cluster stars I. Grid of stellar models with helium enhancement at [Fe/H] =-1.75

Context. Our understanding of the formation and early evolution of globular clusters (GCs) has been totally overthrown with the discovery of the peculiar chemical properties of their long-lived host stars. Aims. As a consequence, the interpretation of the observed color-magnitude diagrams and of the properties of the GC stellar populations requires the use of stellar models computed with relevant chemical compositions. Methods. We present a grid of 224 stellar evolution models for low-mass stars with initial masses between 0.3 and 1.0 M⊙ and initial helium mass fraction between 0.248 and 0.8 computed for [Fe/H] = –1.75 with the stellar evolution code STAREVOL. This grid is made available to the community. Results. We explore the implications of the assumed initial chemical distribution for the main properties of the stellar models: evolution paths in the Hertzsprung-Russel diagram (HRD), duration and characteristics of the main evolutionary phases, and the chemical nature of the white dwarf remnants. We also provide the ranges in initial stellar mass and helium content of the stars that populate the different regions of the HRD at the ages of 10 and 13.4 Gyr, which are typical for Galactic GCs

Combined on-farm effect of plot size and sorghum genotype on sorghum panicle-feeding bug infestation in Mali

The reaction of four sorghum cultivars to panicle-feeding bugs was assessed in small (15 m2) and large (0.5–1.0 ha) plots for 2 years in three villages of the Kolokani region (Mali). The aim was to explain the somewhat contradictory earlier observations of pest infestation and damage in small experimental plots (on-station and on-farm) as well as in farmers’ field surveys. Irrespective of the plot size, the local guinea sorghum cultivar Bibalawili was consistently the least infested and damaged, followed by bug-resistant compact-headed cv Malisor 84-7, whereas the improved caudatum cultivar Gadiabani, which had been disseminated for nearly a decade in the region, and the improved hybrid ICSH 89002, were the most heavily damaged. When located along the border of large plots of a susceptible cultivar, small plots of the four cultivars overall were less infested and damaged than when located along the border of plots of resistant cultivars. However, they were more infested and damaged when located in the centre of large plots of susceptible cultivars than when they were in the centre of resistant cultivar plots. In large plots, bug populations and damage decreased from the border to the centre. These results suggest that, in addition to the mere plot size, plant breeders should take the genotypic environment of their experimental plots into account, namely the vicinity of large plots of pest-susceptible or -resistant cultivars, and the position of the test plots (border or centre) relative to these large plots

Prognostic value of increase in transcript levels of Tp73 ΔEx2-3 isoforms in low-grade glioma patients

Glial tumours are a devastating, poorly understood condition carrying a gloomy prognosis for which clinicians sorely lack reliable predictive parameters facilitating a sound treatment strategy. Tp73, a p53 family member, expresses two main classes of isoforms – transactivatory activity (TA)p73 and ΔTAp73 – exhibiting tumour suppressor gene and oncogene properties, respectively. The authors examined their expression status in high- and low-grade adult gliomas. Isoform-specific real-time reverse transcription-polymerase chain reaction was used for the analysis of Tp73 isoform transcript expression in a series of 51 adult patients harbouring glial tumours, in order to compare tumour grades with each other, and with non-tumoural samples obtained from epileptic patients as well. Our data demonstrate increase of TAp73 and ΔTAp73 transcript levels at onset and early stage of the disease. We also show that ΔEx2–3 isoform expression in low-grade tumours anticipates clinical and imaging progression to higher grades, and correlates to the patients' survival. Expression levels of P1 promoter generated Tp73 isoforms – and particularly ΔEx2–3 – indeed allow for prediction of the clinical progression of low-grade gliomas in adults. Our data are the first such molecular biology report regarding low-grade tumours and as such should be of help for sound decision-making

Massive Sorghum Collection Genotyped with SSR Markers to Enhance Use of Global Genetic Resources

Large ex situ collections require approaches for sampling manageable amounts of germplasm for in-depth characterization and use. We present here a large diversity survey in sorghum with 3367 accessions and 41 reference nuclear SSR markers. Of 19 alleles on average per locus, the largest numbers of alleles were concentrated in central and eastern Africa. Cultivated sorghum appeared structured according to geographic regions and race within region. A total of 13 groups of variable size were distinguished. The peripheral groups in western Africa, southern Africa and eastern Asia were the most homogeneous and clearly differentiated. Except for Kafir, there was little correspondence between races and marker-based groups. Bicolor, Caudatum, Durra and Guinea types were each dispersed in three groups or more. Races should therefore better be referred to as morphotypes. Wild and weedy accessions were very diverse and scattered among cultivated samples, reinforcing the idea that large gene-flow exists between the different compartments. Our study provides an entry to global sorghum germplasm collections. Our reference marker kit can serve to aggregate additional studies and enhance international collaboration. We propose a core reference set in order to facilitate integrated phenotyping experiments towards refined functional understanding of sorghum diversity

HAYDN -- High-precision AsteroseismologY of DeNse stellar fields (ESA Voyage 2050 White Paper)

In the last decade, the Kepler and CoRoT space-photometry missions have demonstrated the potential of asteroseismology as a novel, versatile and powerful tool to perform exquisite tests of stellar physics, and to enable precise and accurate characterisations of stellar properties, with impact on both exoplanetary and Galactic astrophysics. Based on our improved understanding of the strengths and limitations of such a tool, we argue for a new small/medium space mission dedicated to gathering high-precision, high-cadence, long photometric series in dense stellar fields. Such a mission will lead to breakthroughs in stellar astrophysics, especially in the metal poor regime, will elucidate the evolution and formation of open and globular clusters, and aid our understanding of the assembly history and chemodynamics of the Milky Way's bulge and few nearby dwarf galaxies

Women Scientists Who Made Nuclear Astrophysics

Female role models reduce the impact on women of stereotype threat, i.e., of being at risk of conforming to a negative stereotype about one's social, gender, or racial group. This can lead women scientists to underperform or to leave their scientific career because of negative stereotypes such as, not being as talented or as interested in science as men. Sadly, history rarely provides role models for women scientists; instead, it often renders these women invisible. In response to this situation, we present a selection of twelve outstanding women who helped to develop nuclear astrophysics

The Physics of Star Cluster Formation and Evolution

© 2020 Springer-Verlag. The final publication is available at Springer via https://doi.org/10.1007/s11214-020-00689-4.Star clusters form in dense, hierarchically collapsing gas clouds. Bulk kinetic energy is transformed to turbulence with stars forming from cores fed by filaments. In the most compact regions, stellar feedback is least effective in removing the gas and stars may form very efficiently. These are also the regions where, in high-mass clusters, ejecta from some kind of high-mass stars are effectively captured during the formation phase of some of the low mass stars and effectively channeled into the latter to form multiple populations. Star formation epochs in star clusters are generally set by gas flows that determine the abundance of gas in the cluster. We argue that there is likely only one star formation epoch after which clusters remain essentially clear of gas by cluster winds. Collisional dynamics is important in this phase leading to core collapse, expansion and eventual dispersion of every cluster. We review recent developments in the field with a focus on theoretical work.Peer reviewe

Dataset of measurements for the experimental CEA-beam benchmark structure subjected to one stochastic broadband excitation.

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