Detecting gravitational radiation from neutron stars using a six-parameter adaptive MCMC method

We present a Markov chain Monte Carlo technique for detecting gravitational radiation from a neutron star in laser interferometer data. The algorithm can estimate up to six unknown parameters of the target, including the rotation frequency and frequency derivative, using reparametrization, delayed rejection and simulated annealing. We highlight how a simple extension of the method, distributed over multiple computer processors, will allow for a search over a narrow frequency band. The ultimate goal of this research is to search for sources at a known locations, but uncertain spin parameters, such as may be found in SN1987A.Comment: Submitted to Classical and Quantum Gravity for GWDAW-8 proceeding

Muséums, jardins botaniques et Développement durable : quels enjeux pour demain ?

Dans le cadre de la mise en place des politiques publiques territoriales liées au Développement durable, l’auteur montre l’expertise des muséums et des jardins botaniques et leur légitimité à traiter de ces questions – notamment à travers la mise en œuvre de projets participatifs – et plaide à cet égard en faveur de nouvelles formes de partenariat, de mutualisation, de transversalité et de mise en réseau

Homogeneous nucleation in associated vapors. I. Acetic acid

Homogeneous nucleation measurements on acetic acid vapor are reported. The presence of the relatively stable association clusters tends to stabilize the vapor with regard to homogeneous nucleation. The variation of the critical supersaturation with temperature for acetic acid vapor was found to agree well with the predictions of the Katz–Saltsburg–Reiss theory for nucleation in associated vapors

A Directional-Change Events Approach for Studying Financial Time Series

Financial markets witness high levels of activity at certain times, but remain calm at others. This makes the flow of physical time discontinuous. Therefore using physical time scales for studying financial time series, runs the risk of missing important activities. An alternative approach is the use of an event-based time that captures periodic activities in the market. In this paper, we use a special type of event, called a directional-change event, and show its usefulness in capturing periodic market activities. Our study confirms that the length of the price curve coastline as defined by directional-change events, turns out to be a long one

Stationary distributions for diffusions with inert drift

Consider reflecting Brownian motion in a bounded domain in $${\mathbb R^d}$$ that acquires drift in proportion to the amount of local time spent on the boundary of the domain. We show that the stationary distribution for the joint law of the position of the reflecting Brownian motion and the value of the drift vector has a product form. Moreover, the first component is uniformly distributed on the domain, and the second component has a Gaussian distribution. We also consider more general reflecting diffusions with inert drift as well as processes where the drift is given in terms of the gradient of a potential

Le simulateur automatisé BirthSIM pour la formation des obstétriciens

National audienceCet article présente une des fonctionnalités du simulateur d'accouchement BirthSIM : la simulation d'accouchement instrumental. Son objectif est de proposer une nouvelle méthode de formation aux novices obstétriciens pour compléter la formation traditionnelle en salle d'accouchement. En obstétrique il peut être nécessaire d'utiliser des forceps pour extraire le nouveau-né en cas d'urgence, or ces instruments nécessitent une certaine expérience pratique. Cet article présente donc l'approche retenue pour simuler la dynamique d'un accouchement sur le simulateur BirthSIM. Plusieurs procédures sont disponibles sur le simulateur BirthSIM et nous nous intéressons particulièrement à une procédure qui permet de simuler un accouchement instrumental difficile. Afin d'assurer le réalisme de l'extraction sur le simulateur BirthSIM, il est nécessaire de reproduire les différents efforts mis en jeu lors d'un accouchement. Pour cela nous avons retenu une loi de commande originale : un asservissement en position avec un gain variable afin de modifier la raideur du système. Les résultats présentés dans cet article soulignent le besoin des novices d'acquérir une certaine expérience avant de se former classiquement en salle d'accouchement

Dynamics of nanodroplets on topographically structured substrates

Mesoscopic hydrodynamic equations are solved to investigate the dynamics of nanodroplets positioned near a topographic step of the supporting substrate. Our results show that the dynamics depends on the characteristic length scales of the system given by the height of the step and the size of the nanodroplets as well as on the constituting substances of both the nanodroplets and the substrate. The lateral motion of nanodroplets far from the step can be described well in terms of a power law of the distance from the step. In general the direction of the motion depends on the details of the effective laterally varying intermolecular forces. But for nanodroplets positioned far from the step it is solely given by the sign of the Hamaker constant of the system. Moreover, our study reveals that the steps always act as a barrier for transporting liquid droplets from one side of the step to the other.Comment: 44 pages, 25 figure

Genetic Risk Reclassification for Type 2 Diabetes by Age Below or Above 50 Years Using 40 Type 2 Diabetes Risk Single Nucleotide Polymorphisms

OBJECTIVE: To test if knowledge of type 2 diabetes genetic variants improves disease prediction. RESEARCH DESIGN AND METHODS: We tested 40 single nucleotide polymorphisms (SNPs) associated with diabetes in 3,471 Framingham Offspring Study subjects followed over 34 years using pooled logistic regression models stratified by age (<50 years, diabetes cases = 144; or ≥50 years, diabetes cases = 302). Models included clinical risk factors and a 40-SNP weighted genetic risk score. RESULTS: In people <50 years of age, the clinical risk factors model C-statistic was 0.908; the 40-SNP score increased it to 0.911 (P = 0.3; net reclassification improvement (NRI): 10.2%, P = 0.001). In people ≥50 years of age, the C-statistics without and with the score were 0.883 and 0.884 (P = 0.2; NRI: 0.4%). The risk per risk allele was higher in people <50 than ≥50 years of age (24 vs. 11%; P value for age interaction = 0.02). CONCLUSIONS: Knowledge of common genetic variation appropriately reclassifies younger people for type 2 diabetes risk beyond clinical risk factors but not older people