Inference for Partially Observed Multitype Branching Processes and Ecological Applications

Multitype branching processes with immigration in one type are used to model the dynamics of stage-structured plant populations. Parametric inference is first carried out when count data of all types are observed. Statistical identifiability is proved together with derivation of consistent and asymptotically Gaussian estimators for all the parameters ruling the population dynamics model. However, for many ecological data, some stages (i.e. types) cannot be observed in practice. We study which mechanisms can still be estimated given the model and the data available in this context. Parametric inference is investigated in the case of Poisson distributions. We prove that identifiability holds for only a subset of the parameter set depend- ing on the number of generations observed, together with consistent and asymptotic properties of estimators. Finally, simulations are performed to study the behaviour of the estimators when the model is no longer Poisson. Quite good results are obtained for a large class of models with distributions having mean and variance within the same order of magnitude, leading to some stability results with respect to the Poisson assumption.Comment: 31 pages, 1 figur

An innovative blazar classification based on radio jet kinematics

Blazars are usually classified following their synchrotron peak frequency ($\nu F(\nu)$ scale) as high, intermediate, low frequency peaked BL Lacs (HBLs, IBLs, LBLs), and flat spectrum radio quasars (FSRQs), or, according to their radio morphology at large scale, FR~I or FR~II. However, the diversity of blazars is such that these classes seem insufficient to chart the specific properties of each source. We propose to classify a wide sample of blazars following the kinematic features of their radio jets seen in very long baseline interferometry (VLBI). For this purpose we use public data from the MOJAVE collaboration in which we select a sample of blazars with known redshift and sufficient monitoring to constrain apparent velocities. We selected 161 blazars from a sample of 200 sources. We identify three distinct classes of VLBI jets depending on radio knot kinematics: class I with quasi-stationary knots, class II with knots in relativistic motion from the radio core, and class I/II, intermediate, showing quasi-stationary knots at the jet base and relativistic motions downstream. A notable result is the good overlap of this kinematic classification with the usual spectral classification; class I corresponds to HBLs, class II to FSRQs, and class I/II to IBLs/LBLs. We deepen this study by characterizing the physical parameters of jets from VLBI radio data. Hence we focus on the singular case of the class I/II by the study of the blazar BL Lac itself. Finally we show how the interpretation that radio knots are recollimation shocks is fully appropriate to describe the characteristics of these three classes.Comment: 12 pages, 13 figures, accepted by A&

Telling the truth about HIV? Testing and disclosure in a culture of stigma

Étude de cas / Case studyLa stigmatisation du VIH est l'un des obstacles les plus notables à l’accès à des tests individuels, ce qui altère sérieusement les efforts mondiaux dans la lutte contre le VIH / SIDA. Puisque la stigmatisation est fortement ancrée dans les habitudes culturelles et sociales locales, les travailleurs de la santé, qui offrent des programmes humanitaires de dépistage, de conseil et de prévention du VIH dans les pays à faible et moyen revenu (PFR-PRI), sont devenus une alternative sérieuse aux fournisseurs de soins de santé locaux. Cette étude de cas porte sur certains des dilemmes éthiques auxquels les travailleurs de la santé humanitaires doivent faire face lorsqu'ils sont confrontés à la stigmatisation associée au VIH.HIV stigmatization is one of the most notable barriers to individual testing, seriously impairing global efforts in the fight against HIV/AIDS. Because stigmatization is strongly embedded in local cultural and social habits, humanitarian healthcare workers providing HIV testing, counselling and prevention programs in low and middle income countries (LMICs) have become a serious alternative to local healthcare providers. This case study addresses some of the ethical dilemmas that humanitarian healthcare workers face when confronted with HIV-associated stigma

Une bioéthique pour un monde habitable ? La bioéthique en discussion Armell de Bouvet et Jean-Philippe Cobbaut (éds.)

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Maintenance of polymorphism in the orb weaving spider species Agalenatea redii (Araneae, Araneidae)

The maintenance of polymorphism within populations may be the consequence of several elements of species life history such as use of space, activity rhythms, predation, parasitism and reproduction. The present study focuses on the latter aspect using an orb weaving spider, Agalenatea redii, which presents five different morphs of the opisthosoma pattern in the adult stage. Over the course of four years, from 2008 to 2011, adult spiders (males, females and pairs) were observed at different sites. In 2011, we also conducted a six-week survey of a single population, observing the number of spiders of each morph and the morph of paired spiders. We collected field data on the spatial and temporal distribution of spiders based on their sex and morph. Using a distance analysis, we compared the field distribution with a simulated one in which pairs were associated at random. The results showed that although there were changes over time and space in the proportions of females of the different morphs, as well as in the proportion of the pair associations, pairing according to morphs probably occurs at random

Local Convex Hull support and boundary estimation

International audienceIn this paper we introduce a new estimator for the support of a multivariatedensity. It is defined as a union of convex hulls of observations contained in balls of fixed radius.We study the asymptotic behavior of this ``local convex hull" for the estimation of the support and its boundary.When the support is smooth enough, the proposed estimator is proved to be, eventually almost surely, homeomorphic to the support.Numerical simulations on both simulated and real data illustrate the performance of our estimator

Towards a Semantic-based Approach for Modeling Regulatory Documents in Building Industry

Regulations in the Building Industry are becoming increasingly complex and involve more than one technical area. They cover products, components and project implementation. They also play an important role to ensure the quality of a building, and to minimize its environmental impact. In this paper, we are particularly interested in the modeling of the regulatory constraints derived from the Technical Guides issued by CSTB and used to validate Technical Assessments. We first describe our approach for modeling regulatory constraints in the SBVR language, and formalizing them in the SPARQL language. Second, we describe how we model the processes of compliance checking described in the CSTB Technical Guides. Third, we show how we implement these processes to assist industrials in drafting Technical Documents in order to acquire a Technical Assessment; a compliance report is automatically generated to explain the compliance or noncompliance of this Technical Documents