Yeast and yeast-like diversity in the southernmost glacier of Europe (Calderone Glacier, Apennines, Italy)

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Molecular characterization of Prototheca strains isolated from Italian dairy herds.

One hundred sixty-one Prototheca spp. strains isolated from composite milk and barn-surrounding environmental samples (bedding, feces, drinking, or washing water, surface swabs) of 24 Italian dairy herds were characterized by genotype-specific PCR analysis. Overall, 97.2% of strains isolated from composite milk samples were characterized as Prototheca zopfii genotype 2, confirming its role as the main mastitis pathogen, whereas Prototheca blaschkeae was only sporadically isolated (2.8%). Regarding environmental sampling, 84.9% of isolates belonged to P. zopfii genotype 2, 13.2% to P. blaschkeae, and 1.9% to P. zopfii genotype 1. The data herein contradict previous hypotheses about the supposed exclusive role of P. zopfii genotype 2 as the causative agent of protothecal mastitis and, on the contrary, confirm the hypothesis that such pathology could be caused by P. blaschkeae in a few instances

Representations of Antonín Dvořák: A Study of his Music through the Lens of Late Nineteenth-century Czech Criticism

Commenting on Antonín Dvořák (1841–1904), music critic Václav Juda Novotný declared in 1881 that “a Czech composer has to write, first and foremost, for a Czech audience.” Scholars have given considerable attention to Dvořák’s reception abroad and have shown that his path to success on foreign stages, particularly in Vienna, was not always direct. The composer’s reception in the Czech lands during the late nineteenth century was no less complicated – shaped by various cultural and political factors, as the Czechs sought to assert themselves in the fight for the nationalist cause, while remaining under Habsburg rule. Drawing on the wealth of newspaper and journal articles that were printed in the Czech press at this time, the dissertation places Dvořák’s music into its Czech context. The topic is explored by way of three case studies that deal with Dvořák’s contributions to choral, operatic, and symphonic genres. Each of the works examined came at a significant moment in Dvořák’s career in the Czech lands. The performance in 1873 of the choral cantata Hymnus: Heirs of the White Mountain marked Dvořák’s professional debut; with the 1878 production of the comic opera The Cunning Peasant, Dvořák celebrated his first major triumph on the coveted Czech operatic stage; and the Prague premiere in 1881 of his first widely recognized symphony, the D major, Op. 60, proved to be crucial in defining Dvořák’s role in the concert hall. These case studies reveal that Dvořák’s treatment in the Czech press varied depending on the unique traditions of these genres and their differing status within Czech musical culture. The project highlights the complex relationships and interactions among critics, audiences, and composers. In the politically-charged climate of fin-de-siècle Bohemia, Czech critics took ownership of Dvořák and enlisted his music to advance their own agendas. Dvořák, in turn, was keenly aware of and often catered to public tastes and critical expectations. Intertwining various realms of contextual inquiry, including nationalist rhetoric, contemporary critical discourses, and the musical repertories that were cultivated in the Czech lands, the dissertation draws attention to the multiple agents at play in Dvořák’s nineteenth-century Czech reception.Ph

On population growth with catastrophes

International audienc

ON POPULATION GROWTH WITH CATASTROPHES

Deterministic population growth models can exhibit a large variety of flows, ranging from algebraic, exponential to hyper-exponential (with finite time explosion). They describe the growth for the size (or mass) of some population as time goes by. Variants of such models are introduced allowing logarithmic, exp-algebraic or even doubly exponential growth. The possibility of immigration is also raised. An important feature of such growth models is to decide whether the ground state 0 is reflecting or absorbing and also whether state ∞ is accessible or inaccessible. We then study a semi-stochastic catastrophe version of such models (also known as Piecewise-Deterministic-Markov Processes, in short, PDMP). Here, at some jump times, possibly governed by state-dependent rates, the size of the population shrinks by a random amount of its current size, an event possibly leading to instantaneous local (or total) extinction. A special shrinkage transition kernel is investigated in more detail, including the case of total disasters. Between the jump times, the new process grows, following the deterministic dynamics started at the newly reached state after each jump. We discuss the conditions under which such processes are either transient or recurrent (posi-tive or null), the scale function playing a key role in this respect, together with the speed measure cancelling the Kolmogorov forward operator. The scale function is also used to compute, when relevant, the law of the height of excursions. The question of the finiteness of the time to extinction is investigated together (when finite), with the evaluation of the mean time to extinction, either local or global. Some information on the embedded chain to the PDMP is also required when dealing with the classification of states 0 and ∞ that we exhibit

On decay-surge population models

A paraitre: Advances in Applied Probability 55.2 (2023

Explicit solvation effects on low-index Fe surfaces and small particles as adsorbents of Arsenic species: A DFT study

Density functional theory (DFT) calculations were carried out on hydroxylated and solvated (H&S) Fe substrates. Fe (110) and (111) extended surfaces as well as clusters of 32 and 59 atoms, and a nanoparticle of 80 atoms were studied as adsorbent substrates of harmful As species. Arsenious (H3AsO3) and arsenic (H3AsO4) acids are physisorbed on the H&S Fe(110) but chemisorbed on the H&S Fe(111) surface. The open-packed plane of the (111) surface, with free active sites, allows better interaction with the acid molecules. The small hydroxylated cluster, Fe32, has shown the best activity as adsorbent of H3AsO3. Electronic charge transfer occurs not only from Fe atoms that directly interact with the acid molecule, but neighbouring Fe atoms are also oxidized. This work presents clear evidence that these spherical Fe aggregates, formed mainly by (111) faces and with an important percentage of low-coordination sites, are excellent adsorbent substrates of H3AsO3 and should be considered as a reference to search for new supported catalysts.Fil: Alfonso Tobón, Leslie Lissette. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Física del Sur. Universidad Nacional del Sur. Departamento de Física. Instituto de Física del Sur; ArgentinaFil: Branda, María Eva. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich". Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich"; Argentin

Whole genome sequencing of human Borrelia burgdorferi isolates reveals linked blocks of accessory genome elements located on plasmids and associated with human dissemination.

Lyme disease is the most common vector-borne disease in North America and Europe. The clinical manifestations of Lyme disease vary based on the genospecies of the infecting Borrelia burgdorferi spirochete, but the microbial genetic elements underlying these associations are not known. Here, we report the whole genome sequence (WGS) and analysis of 299 B. burgdorferi (Bb) isolates derived from patients in the Eastern and Midwestern US and Central Europe. We develop a WGS-based classification of Bb isolates, confirm and extend the findings of previous single- and multi-locus typing systems, define the plasmid profiles of human-infectious Bb isolates, annotate the core and strain-variable surface lipoproteome, and identify loci associated with disseminated infection. A core genome consisting of ~900 open reading frames and a core set of plasmids consisting of lp17, lp25, lp36, lp28-3, lp28-4, lp54, and cp26 are found in nearly all isolates. Strain-variable (accessory) plasmids and genes correlate strongly with phylogeny. Using genetic association study methods, we identify an accessory genome signature associated with dissemination in humans and define the individual plasmids and genes that make up this signature. Strains within the RST1/WGS A subgroup, particularly a subset marked by the OspC type A genotype, have increased rates of dissemination in humans. OspC type A strains possess a unique set of strongly linked genetic elements including the presence of lp56 and lp28-1 plasmids and a cluster of genes that may contribute to their enhanced virulence compared to other genotypes. These features of OspC type A strains reflect a broader paradigm across Bb isolates, in which near-clonal genotypes are defined by strain-specific clusters of linked genetic elements, particularly those encoding surface-exposed lipoproteins. These clusters of genes are maintained by strain-specific patterns of plasmid occupancy and are associated with the probability of invasive infection