Time-dependent H2 formation and protonation

Methods: The microscopic equations of H2-formation and protonation are integrated numerically over time in such a manner that the overall structures evolve self-consistently under benign conditions. Results: The equilibrium H2 formation timescale in an H I cloud with N(H) ~ 4x10^{20}/cm^2 is 1-3 x 10^7 yr, nearly independent of the assumed density or H2 formation rate constant on grains, etc. Attempts to speed up the evolution of the H2-fraction would require densities well beyond the range usually considered typical of diffuse gas. The calculations suggest that, under benign, quiescent conditions, formation of H2 is favored in larger regions having moderate density, consistent with the rather high mean kinetic temperatures measured in H2, 70-80 K. Formation of H3+ is essentially complete when H2-formation equilibrates but the final abundance of H3+ appears more nearly at the very last instant. Chemistry in a weakly-molecular gas has particular properties so that the abundance patterns change appreciably as gas becomes more fully molecular, either in model sequences or with time in a single model. One manifestation of this is that the predicted abundance of H3+ is much more weakly dependent on the cosmic-ray ionization rate when n(H2)/n(H) < 0.05. In general, high abundances of H3+ do not enhance the abundances of other species (e.g. HCO+) but late-time OH formation proceeds most vigourously in more diffuse regions having modest density, extinction and H2 fraction and somewhat higher fractional ionization, suggesting that atypically high OH/H2 abundance ratios might be found optically in diffuse clouds having modest extinction

Multi-Head Adapter Routing for Data-Efficient Fine-Tuning

Parameter-efficient fine-tuning (PEFT) methods can adapt large language models to downstream tasks by training a small amount of newly added parameters. In multi-task settings, PEFT adapters typically train on each task independently, inhibiting transfer across tasks, or on the concatenation of all tasks, which can lead to negative interference. To address this, Polytropon (Ponti et al.) jointly learns an inventory of PEFT adapters and a routing function to share variable-size sets of adapters across tasks. Subsequently, adapters can be re-combined and fine-tuned on novel tasks even with limited data. In this paper, we investigate to what extent the ability to control which adapters are active for each task leads to sample-efficient generalization. Thus, we propose less expressive variants where we perform weighted averaging of the adapters before few-shot adaptation (Poly-mu) instead of learning a routing function. Moreover, we introduce more expressive variants where finer-grained task-adapter allocation is learned through a multi-head routing function (Poly-S). We test these variants on three separate benchmarks for multi-task learning. We find that Poly-S achieves gains on all three (up to 5.3 points on average) over strong baselines, while incurring a negligible additional cost in parameter count. In particular, we find that instruction tuning, where models are fully fine-tuned on natural language instructions for each task, is inferior to modular methods such as Polytropon and our proposed variants.Comment: Preprin

Guide de droit d\u27auteur

Ce guide, à jour des textes en vigueur en cette année 2017, traite des questions juridiques soulevées en droit de la propriété intellectuelle. Il constitue l\u27outil indispensable à tous ceux qui sont amenés à utiliser ou à créer des ressources, quelles que soient leurs natures

Etude du marché français des algues alimentaires. Panorama de la distribution. Programme IDEALG Phase 2 - Programme IDEALG Phase 2. Les publications du Pôle halieutique AGROCAMPUS OUEST n°36

Le projet IDEALG a pour objectif de développer la filière des macro-algues en France à travers de nombreux axes de recherche. Le Pôle halieutique AGROCAMPUS OUEST, s’intéresse plus particulièrement aux algues alimentaires françaises. La problématique d’étude traitée au sein du Pôle halieutique AGROCAMPUS OUEST est donc la suivante : «Comment développer le marché des algues alimen-taires?».Après une étude nationale de la consommation, l’équipe du Pôle halieutique s’est intéressée à des questions de marché. Ce document présente l’ensemble des résultats obtenus grâce à une analyse de l’offre en produits aux algues de 111 magasins physiques dispersés dans 7 villes françaises. Cette étude permet de faire un état des lieux et une cartographie de la distribution des produits aux algues en France en 2014

The role of reflective practice in healthcare professions: Next steps for pharmacy education and practice

Reflective practice strategies can enable healthcare practitioners to draw on previous experiences to render more effective judgment in clinical situations. The central argument presented in this commentary is that education programs and structures for continuing professional development (CPD) and revalidation of professionals sharpen their focus regarding self-assessment to identify gaps in skills and attitudes rather than merely as a means of on-going monitoring. Pharmacy undergraduate and professional education need to promote reflective practice strategies that foster self-evaluation to promote pharmacists’ readiness for practice change and advance patient care within rapidly expanding roles and scope of practice

Plasma amino-acid determinations by reversed-phase HPLC: Improvement of the orthophthalaldehyde method and comparison with ion exchange chromatography

Reversed-phase high performance liquid chromatographic (RPHPLC) determination of amino-acids with on-line pre-column ortho-phthalaldehyde (OPA) derivatization and fluorescence detection is rapid and sensitive. However, high-performance ionexchange chromatography (HP-IEC) with post-column ninhydrine reaction is the most widely used amino-acid (AA) assay for biological samples. These two methods have been compared for the determination of individual plasma AA concentrations

Motile bacteria, active biohybrids and cellular physiology

This thesis investigates bacterial motility from active matter and physiological perspectives using experiments and theoretical modelling. In the first part, I design and characterize a system made of motile Escherichia coli encapsulated in giant lipid vesicles. For slightly deflated vesicles, the bacteria extrude active membrane tubes that can propel the vesicles. I show that the propulsion arises from a physical coupling between the lipid membrane tubes and the flagella of the encapsulated bacteria and develop a simple theoretical model to estimate the propulsive force. In a second part, I present two studies using motility as a tool to gain insight into bacterial physiology. First, I study the motility of dense suspensions of Escherichia coli fermenting glucose. Using new experimental data gathered by others, I develop a semi-empirical model that quantitatively links the swimming speed of the bacteria to the concentration of protonated organic acids in anaerobic conditions. Secondly, I focus on bacterial motility during complete starvation. Combining single-cell and population-level experiments, I show that Escherichia coli maintains a motile phenotype in the early stages of starvation, but that the swimming speed and motile fraction decay over a few tens of hours. I show that the complete decay of motility in these conditions happens on a much faster timescale than cell death. Interestingly, while swimming speed and flagellar motor measurements both show that the motility fully decays in about 24 h in these conditions, they seem to return different temporal dynamics

La critique parisienne et la légitimation du free jazz. Vers une politisation du commentaire esthétique (1959-1965)

Cet article s’attache à montrer au sein des deux grandes revues françaises spécialisées de jazz – Jazz Hot et Jazz Magazine – les enjeux liés à leur découverte du free jazz joué par les musiciens afro-américains entre 1959 et 1965  : d’une part, les interprètes s’en revendiquent pour s’émanciper d’une étiquette «  jazz » jugée trop rigide et connotée  ; de l’autre, il est l’objet d’une nouvelle théâtralisation d’un conflit esthétique, légitimant une nouvelle génération de critiques qui politise le commentaire esthétique.This article tackles the issue of the discovery of free jazz by African American musicians between 1959 and 1965 in two major jazz-specialized French periodicals – Jazz Hot and Jazz Magazine. On the one hand, it deals with the fact that such musicians tend to claim their affiliations to free jazz, thus emancipating from a “jazz label” that would seem too rigid and connoted ; on the other hand, free jazz is also subject to a new dramatization of an aesthetic conflict, that would legitimatise a new generation of critics that politicizes aesthetic reviews