Capacity utilization dynamics and market power

In an intertemporal general equilibrium model with imperfect competition, we settle a relationship between factor utilization and markups, via the effect of capacity utilization rate changes on firms' market power when the demand for goods is uncertain. When competition is imperfect, the existence of capacity constraints introduces a distinction between demand and sales price elasticities. At given demand price elasticity, the price elasticity of sales will be smaller the larger the aggregate capacity utilization rateo In such a framework, capacity utilization aifects the propagation mechanism of exogenous disturbances in two ways. The first effect is similar to the effect that bottlenecks and stockouts would have in a perfectly competitive setup; the second effect is related to imperfect competition and works through market power and optimal markup changes. We study these interactions and their implications for the dynamic behavior of sorne key macro variables in response to various "structural" changes. We show that the same shock can have quite different short run effects depending on the characteristics of the initial stationary state (low or high capacity utilization rate)

Capacity utilization and market power.

In a monopolistic competition framework, we propose a dynamic model in which capacity underutilization is a macroeconomic equilibrium feature relying on a diversity of microeconomic situations. Capacity underutilization follows from microeconomic uncertainty at the time firms must decide on their productive capacity. We settle a relationship between capacity utilization and markups via the effect of capacity utilization rate changes on firms' market power. We show that such a relationship influences significantly the short run response of the economy to exogenous shocks. In particular, the same shock can have quite different short run effects depending on the characteristics of the initial stationary state (low or high capacity utilization rate).Capacity Utilization; Markups; Monopolistic Competition; Market Power;

Capacity utilization dynamics and market power.

In an intertemporal general equilibrium model with imperfect competition, we settle a relationship between factor utilization and markups, via the effect of capacity utilization rate changes on firms' market power when the demand for goods is uncertain. When competition is imperfect, the existence of capacity constraints introduces a distinction between demand and sales price elasticities. At given demand price elasticity, the price elasticity of sales will be smaller the larger the aggregate capacity utilization rateo In such a framework, capacity utilization aifects the propagation mechanism of exogenous disturbances in two ways. The first effect is similar to the effect that bottlenecks and stockouts would have in a perfectly competitive setup; the second effect is related to imperfect competition and works through market power and optimal markup changes. We study these interactions and their implications for the dynamic behavior of sorne key macro variables in response to various "structural" changes. We show that the same shock can have quite different short run effects depending on the characteristics of the initial stationary state (low or high capacity utilization rate).Business Cycle; Capacity Utilization; Market Power; Markup Rate;

Estimation de la réponse impulsionnelle spatiale d'un système d'optique adaptative à partir des données de contrôle de boucle

Nous proposons une nouvelle méthode permettant d'estimer la réponse impulsionnelle spatiale d'un système d'optique adaptative pour l'astronomie. Celle-ci dépend fortement des conditions d'acquisition et sa connaissance est essentielle afin de pouvoir améliorer, à l'aide d'algorithmes de déconvolution, le contraste des images acquises. La méthode proposée est plus précise que les méthodes habituellement mises en oeuvre car elle se base sur des données parfaitement synchrones avec l'acquisition. De plus, elle n'occasionne pas de perte de temps d'observation. Sur le Télescope Canada-France-Hawaii, de très bons résultats ont pu être obtenus, pour des sources de référence de magnitude inférieure ou égale à 13

Bio-Based Polyricinoleate and Polyhydroxystearate: Properties and Evaluation as Viscosity Modifiers for Lubricants

This paper aims to design bio-based polyester as a viscosity modifier for lubricant properties. Bio-based polyricinoleate (PRic) and its saturated homologous polyhydroxystearate (PHS) have been synthesized from fatty acid methyl esters. The polycondensation performed in bulk in a one-step reaction without any purification leads to two series of polyesters within a large range of molecular weights, with Mw between 3 and 130 kg·mol–1. Their thermal properties were investigated. Good thermal stability was observed with degradation temperatures above 300 °C. As expected, PRic appeared to be amorphous with a particularly low glass-transition temperature, while PHS is semicrystalline. A rheological study determined that polyricinoleate entangled when its molecular weight was above 25 kg·mol–1. These two bio-based and biodegradable polymers were then evaluated as viscosity modifiers in both organic and mineral oils. PHS with high molecular weights appeared to be an excellent thickener as well as a good viscosity index improver with a viscosity index (VI) increase above +50 in organic lubricant oil and +64 in mineral oil

Ancient origin of somatic and visceral neurons

Background: A key to understanding the evolution of the nervous system on a large phylogenetic scale is the identification of homologous neuronal types. Here, we focus this search on the sensory and motor neurons of bilaterians, exploiting their well-defined molecular signatures in vertebrates. Sensorimotor circuits in vertebrates are of two types: somatic (that sense the environment and respond by shaping bodily motions) and visceral (that sense the interior milieu and respond by regulating vital functions). These circuits differ by a small set of largely dedicated transcriptional determinants: Brn3 is expressed in many somatic sensory neurons, first and second order (among which mechanoreceptors are uniquely marked by the Brn3+/Islet1+/Drgx+ signature), somatic motoneurons uniquely co-express Lhx3/4 and Mnx1, while the vast majority of neurons, sensory and motor, involved in respiration, blood circulation or digestion are molecularly defined by their expression and dependence on the pan-visceral determinant Phox2b. Results: We explore the status of the sensorimotor transcriptional code of vertebrates in mollusks, a lophotrochozoa clade that provides a rich repertoire of physiologically identified neurons. In the gastropods Lymnaea stagnalis and Aplysia californica, we show that homologues of Brn3, Drgx, Islet1, Mnx1, Lhx3/4 and Phox2b differentially mark neurons with mechanoreceptive, locomotory and cardiorespiratory functions. Moreover, in the cephalopod Sepia officinalis, we show that Phox2 marks the stellate ganglion (in line with the respiratory — that is, visceral— ancestral role of the mantle, its target organ), while the anterior pedal ganglion, which controls the prehensile and locomotory arms, expresses Mnx. Conclusions: Despite considerable divergence in overall neural architecture, a molecular underpinning for the functional allocation of neurons to interactions with the environment or to homeostasis was inherited from the urbilaterian ancestor by contemporary protostomes and deuterostomes

An Assessment of Different Genomic Approaches for Inferring Phylogeny of Listeria monocytogenes

Background/objectives: Whole genome sequencing (WGS) has proven to be a powerful subtyping tool for foodborne pathogenic bacteria like L. monocytogenes. The interests of genome-scale analysis for national surveillance, outbreak detection or source tracking has been largely documented. The genomic data however can be exploited with many different bioinformatics methods like single nucleotide polymorphism (SNP), core-genome multi locus sequence typing (cgMLST), whole-genome multi locus sequence typing (wgMLST) or multi locus predicted protein sequence typing (MLPPST) on either core-genome (cgMLPPST) or pan-genome (wgMLPPST). Currently, there are little comparisons studies of these different analytical approaches. Our objective was to assess and compare different genomic methods that can be implemented in order to cluster isolates of L. monocytogenes.Methods: The clustering methods were evaluated on a collection of 207 L. monocytogenes genomes of food origin representative of the genetic diversity of the Anses collection. The trees were then compared using robust statistical analyses.Results: The backward comparability between conventional typing methods and genomic methods revealed a near-perfect concordance. The importance of selecting a proper reference when calling SNPs was highlighted, although distances between strains remained identical. The analysis also revealed that the topology of the phylogenetic trees between wgMLST and cgMLST were remarkably similar. The comparison between SNP and cgMLST or SNP and wgMLST approaches showed that the topologies of phylogenic trees were statistically similar with an almost equivalent clustering.Conclusion: Our study revealed high concordance between wgMLST, cgMLST, and SNP approaches which are all suitable for typing of L. monocytogenes. The comparable clustering is an important observation considering that the two approaches have been variously implemented among reference laboratories

Invest Ophthalmol Vis Sci

PURPOSE. Albinism is a group of genetic disorders that includes several conditions related to a defect in melanin production. There is a broad phenotypic and genotypic variability between the different forms. The aim of this study was to assess the ophthalmologic characteristics according to patients' genotypes in a cohort followed in the Reference Center for oculocutaneous albinism (OCA) of Bordeaux University Hospital, France.METHODS. A retrospective observational study was conducted in a cohort of patients with OCA seen in consultation in the ophthalmology department between 2017 and 2021 in whom a genetic analysis was performed.RESULTS. In total, 127 patients with OCA were included in this study and matched with the results of the genetic analysis. In the population aged over 6 years, there was no statistical difference in binocular visual acuity between the OCA1, OCA2, and OCA4 forms (P = 0.27). There was difference in ametropia between the three forms (P = 0.003). A twoby-two comparison using the Bonferroni correction showed a significant difference in ametropia between the OCA2 and OCA4 forms (P = 0.007) and between the OCA1 and OCA2 forms (P = 0.0075). Regardless of the form, most patients (75.4%) had grade 4 foveal hypoplasia. There was no association between the grade of foveal hypoplasia and the gene involved (P = 0.87).CONCLUSIONS. We described a genotype-phenotype correlation for the three most represented forms of albinism in our cohort. This study allowed assessing the degree of visual deficiency in young children with OCA

The diversity of population responses to environmental change

This is the final version. Available from Wiley via the DOI in this record.Data available from the Dryad Digital Repository: https:// doi.org/10.5061/dryad.d5f54s7The current extinction and climate change crises pressure us to predict population dynamics with ever-greater accuracy. Although predictions rest on the well-advanced theory of age-structured populations, two key issues remain poorly explored. Specifically, how the age-dependency in demographic rates and the year-to-year interactions between survival and fecundity affect stochastic population growth rates. We use inference, simulations and mathematical derivations to explore how environmental perturbations determine population growth rates for populations with different age-specific demographic rates and when ages are reduced to stages. We find that stage- vs. age-based models can produce markedly divergent stochastic population growth rates. The differences are most pronounced when there are survival-fecundity-trade-offs, which reduce the variance in the population growth rate. Finally, the expected value and variance of the stochastic growth rates of populations with different age-specific demographic rates can diverge to the extent that, while some populations may thrive, others will inevitably go extinct.Max Planck Society, Marie Curie FellowshipERCGerman Research FoundationSwiss National Science FoundationNational Science FoundationNational Institute of AgingRamon y Cajal Research GrantWenner-Gren FoundationLeakey FoundationNational Geographic SocietyZoological Society of San DiegoUniversity of PennsylvaniaArgentinean National Council of Researc

Database of pleistocene periglacial featuresin France: description of the online version

A database of Pleistocene periglacial features in France has been compiled from a review of academic literature and reports of rescue archaeology, the analysis of aerial photographs and new field surveys. Polygons, soil stripes, ice-wedge pseudomorphs, sand wedges and composite wedge pseudomorphs are included in the database together with their geographic coordinates, geological context, description and associated references. It is hoped that this database, which aim is to be integrated in broader studies, will stimulate further work on past permafrost reconstruction and will favour greater understanding of the climatic events that lead to the formation of the periglacial features. The database is available online on the AFEQ-CNF INQUA website (https://afeqeng.hypotheses.org/487). A folder that contains photographs and sketches of the features is also available on request.Une base de données des structures périglaciaires pléistocènes de France a été créée à partir d’une revue de la littérature scientifique, de rapports d’archéologie préventive, de l’analyse de photographies aériennes et de nouvelles prospections de terrain. Les polygones, les sols striés, les pseudomorphoses de coin de glace, les coins de sable et les pseudomorphoses de coin composite ont été répertoriés dans la base de données avec leurs coordonnées géographiques, le contexte géologique, leur description et les références bibliographiques associées. Nous espérons que cette base de données, dont le but est d’être intégrée dans des études plus larges, stimulera de prochains travaux sur la reconstitution du pergélisol pléistocène et favorisera une plus grande compréhension des événements climatiques qui ont conduit à la formation de ces structures périglaciaires. La base de données est disponible en ligne sur le site de l’AFEQ-CNF INQUA (https://afeqeng.hypotheses.org/487). Un dossier contenant les photographies et dessins des structures périglaciaires est également disponible sur demande