Finding an unknown number of multivariate outliers

We use the forward search to provide robust Mahalanobis distances to detect the presence of outliers in a sample of multivariate normal data. Theoretical results on order statistics and on estimation in truncated samples provide the distribution of our test statistic. We also introduce several new robust distances with associated distributional results. Comparisons of our procedure with tests using other robust Mahalanobis distances show the good size and high power of our procedure. We also provide a unification of results on correction factors for estimation from truncated samples

Deconstructing the First Time: An Enthographic Approach to the Myth of Virginity Loss

This thesis analyzes the myth of virginity through the experiences of a group of my hometown friends and colleagues of GEMMA Master. Starting from the dominant heteronormative event of the first time, I identify and discuss the main assumptions, beliefs and symbols emerged in relation to the myth, trying to expose its contradictions and deconstruct its imposed, harmful truths, finally proposing what I deem should be primary within the discourses girls and women receive since their entrance into sexuality. The theoretical framework is developed through the analysis of virginity loss as a ritual, and of the hegemonic definitions of sex (as heteronormative, cissexist, phallo- and coitocentric, macho-oriented both in agency and pleasure) and love (as romantic), so inextricably tied together within the rhetoric of virginity and by this same one reflected. Through a chronological division of the themes: before-during-after the first time, I analyze the wait, thus the criteria through which participants identify the «right» person/moment, their expectations, fears and questioning related to the first time, and the preparation of the body. I proceed discussing the multiple lacks within the event of the first time: «experience» on sex, agency, pleasure and any other acts apart from penis penetration. The focus of the following chapter is constituted by the body and the beliefs of its change after the first time, whose discussion is developed mainly around the hymen, blood and vagina size. In this chapter, I also deal with the idea of the first time sex as a contamination, with references to the phenomenon of virgin’s body erotization. This path is concluded with some alternative definitions proposed by participants in relation to the first time, together with persisting worries and difficulties they identified/experienced within non-heterosexual contexts (relationships and feminist/queer spaces), such as managing to eradicate coitocentrism and romantic love.Esta tesis analiza el mito de la virginidad a través de las experiencias de un grupo de amigxs de mi lugar natal y colegas del Máster GEMMA. Empezando por el evento heteronormativo dominante de la primera vez, identifico y discuto las principales suposiciones, creencias y símbolos que emergen con relación a este mito, intentando exponer sus contradicciones y deconstruir sus verdades impuestas y dañinas, proponiendo por fin lo que considero debería ser primario en los discursos que las chicas y las mujeres reciben desde su entrada en la sexualidad. El marco teórico está desarrollado a través del análisis de la pérdida de la virginidad como ritual, y de las definiciones hegemónicas de sexo (como heteronormativo, cissexista, phallo- y coitocentrico, orientado al varón - macho - tanto en la agencia como en el placer) y de amor (como romántico), tan inextricablemente imbricadas dentro de la retórica de la virginidad y reflejadas por esta última. Así, a través de una división cronológica de los temas: antes-durante-después de la primera vez, analizo la espera, o sea los criterios a través de los cuales lxs participantes identifican la persona/momento «justa/o», sus expectativas, miedos y cuestionamientos relativos a la primera vez, y la preparación del cuerpo. Continúo discutiendo las múltiples faltas durante el evento de la primera vez: de «experiencia» en el sexo, de agencia, de placer y de cualquier otro acto aparte de la penetración del pene. El enfoque del capítulo siguiente está constituido por el cuerpo y las creencias sobre su cambio después de la primera vez, cuya discusión se desarrolla principalmente acerca del himen, la sangre y el tamaño de la vagina. En este capítulo, trato también la idea de sexo de la primera vez como contaminación, con referencias al fenómeno de la erotización del cuerpo de la virgen. Esta ruta se concluye con algunas definiciones alternativas propuestas por parte de lxs participantes con relación a la primera vez, juntamente a unas persistentes preocupaciones y dificultades que ellxs mismxs identificaron o conocieron por experiencia propia en contextos non-heterosexuales (relacionamientos y espacios feministas/queer) como conseguir erradicar el coitocentrismo y el amor romántico.MÁSTER ERASMUS MUNDUS GEMMA. X EDICIÓ

Effect of the essential oil of Minthostachys verticillata (Griseb.) epling and limonene on biofilm production in pathogens causing bovine mastitis

Bovine mastitis causes large annual economic losses around the world. Different microorganisms are associated with the disease. The capacity of pathogens to adhere to bovine mammary epithelial cells is associated with biofilm production which leads to antibiotic resistance. Research is now leading to search alternative control methods and medicinal plants constitute a natural, safe, effective and inexpensive option. Minthostachys verticillata is an autochthonous medicinal plant of Argentina with multiple ethnobotanical properties. In a previous study, we demonstrated that the essential oil (EO) of this species and limonene, one of its compounds, inhibited the growth of mastitis pathogens. The objective of the present work was to determine the inhibitory effect of the essential oil of M. verticillata and limonene, on biofilm formation and on mature biofilm produced by pathogens isolated from bovine mastitis. Time kill assay and bacterial lysis were also determined. Furthermore, RAPD-PCR assays were performed to determine changes in bacterial DNA after EO and limonene exposition. Bacterial isolates were identified as Escherichia coli (EC3 and EC9), Bacillus pumilus (BP5, BP6, and BP7) and Enterococcus faecium (EF1) by rRNA 16S sequencing and MALDI-TOF MS. All the strains were able to form biofilm. Addition of both lactose and sucrose did not affect biofilm production. MIC values for EO were 3.6 mg/ml for E. faecium; 0.9 mg/ml for E. coli (EC3), 14.5 mg/ml for E. coli (EC9), 1.8 mg/ml for B. pumilus (BP7), 3.63 mg/ml for B. pumilus (BP6) and 29.0 mg/ml for B. pumilus (BP7). MIC values for limonene were 6.6 mg/ml for B. pumilus (BP6) and 105 mg/ml for B. pumilus (BP5). These results demonstrated that EO was more effective than limonene, showing also bactericidal action against E. faecium (minimal inhibitory concentration (MBC) = 29.0 mg/ml). This result was corroborated by time of death assay, observing a cell decrease after at 6 h, and then by bacterial lysis assay. Both EO and limonene affected mature biofilm of isolated strains. The results contribute to the study of EO and limonene which may serve as a therapy against bovine mastitis pathogens inhibiting the development of pathogenic bacteria.Fil: Cerioli, Maria Florencia. Universidad Nacional de Río Cuarto; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Moliva, Melina Vanesa. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Río Cuarto; ArgentinaFil: Cariddi, Laura Noelia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Río Cuarto; ArgentinaFil: Reinoso, Elina Beatríz. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Río Cuarto; Argentin

On planet formation in HL Tau

We explain the axisymmetric gaps seen in recent long-baseline observations of the HL Tau protoplanetary disc with the Atacama Large Millimetre/Submillimetre Array (ALMA) as being due to the different response of gas and dust to embedded planets in protoplanetary discs. We perform global, three dimensional dusty smoothed particle hydrodynamics calculations of multiple planets embedded in dust/gas discs which successfully reproduce most of the structures seen in the ALMA image. We find a best match to the observations using three embedded planets with masses of 0.2, 0.27 and 0.55 $M_{\rm J}$ in the three main gaps observed by ALMA, though there remain uncertainties in the exact planet masses from the disc model.Comment: 5 pages, 4 figures. Accepted for publication in MNRAS Letters. The movie of the simulation is available at https://www.youtube.com/watch?v=CKenxfslBMY and https://www.youtube.com/watch?v=mGCfjrb5bT

The Forward Search for Very Large Datasets

The identification of atypical observations and the immunization of data analysis against both outliers and failures of modeling are important aspects of modern statistics. The forward search is a graphics rich approach that leads to the formal detection of outliers and to the detection of model inadequacy combined with suggestions for model enhancement. The key idea is to monitor quantities of interest, such as parameter estimates and test statistics, as the model is fitted to data subsets of increasing size. In this paper we propose some computational improvements of the forward search algorithm and we provide a recursive implementation of the procedure which exploits the information of the previous step. The output is a set of efficient routines for fast updating of the model parameter estimates, which do not require any data sorting, and fast computation of likelihood contributions, which do not require matrix inversion or qr decomposition. It is shown that the new algorithms enable a reduction of the computation time by more than 80%. Furthemore, the running time now increases almost linearly with the sample size. All the routines described in this paper are included in the FSDA toolbox for MATLAB which is freely downloadable from the internet.JRC.G.2-Global security and crisis managemen

Characterizing intersection graphs of substars of a star by forbidden subgraphs

Starlike graphs are the intersection graphs of substars of a star. We describe characterizations by forbidden subgraphs for starlike graphs and for a special subclass of it

Tempered positive Linnik processes and their representations

This paper analyzes various classes of processes associated with the tempered positive Linnik (TPL) distribution.We provide several subordinated representations of TPL Lévy processes and in particular establish a stochastic self-similarity property with respect to negative binomial subordination. In finite activity regimes we show that the explicit compound Poisson representations give raise to innovations following Mittag-Leffler type laws which are apparently new. We characterize two time-inhomogeneous TPL processes, namely the Ornstein-Uhlenbeck (OU) Lévy-driven processes with stationary distribution and the additive process determined by a TPL law. We finally illustrate how the properties studied come together in a multivariate TPL Lévy framework based on a novel negative binomial mixing methodology. Some potential applications are outlined in the contexts of statistical anti-fraud and financial modelling