Translations in the exponential Orlicz space with Gaussian weight

We study the continuity of space translations on non-parametric exponential families based on the exponential Orlicz space with Gaussian reference density.Comment: Submitted to GSI 2017, Pari

MICROORGANISMS ASSOCIATED WITH HARD TICKS (IXODIDAE):FROM SYMBIONTS TO TICK-BORNE PATHOGENS

The research activity I developed during my doctorate can be divided into three parts. First, I investigated the genetic variability of Ixodes ricinus in Europe and North Africa also screening for the presence of bacteria belonging to Borrelia burgdorferi sensu latu complex. A second part of the work focused on Midichloria mitochondrii the principal endosymbiont of I. ricinus. This intramitochondrial bacterium is also present in other tick species but information on the exact intracellular location are not available for the majority of them. I decided to perform a molecular screening for detection of Midichloria-like organisms in vertebrates comprehending humans. Finally, the last part of this work provide information on presence of Ixodes ricinus and other tick species in areas (and from hosts) where record of the presence of these arthropods were absent or fragmentary; the ticks collected were also screened for the presence of different tick-borne pathogens. The genetic analysis on both two mitochondrial loci (COI and COII) and two nuclear loci (Defensin and TROSPA) of Ixodes ricinus confirmed the existence of two distinct groups of haplotypes showing a clear geographic pattern. The first group comprises individuals collected in the European continent, while the second group comprises individuals collected in Tunisia, North Africa. The existence of two groups of populations genetically differentiated in the two continents is also supported by the spatial analysis of molecular variance (SAMOVA), congruently for both mtDNA loci and the two nuclear loci. In previous studies on European and Northern African populations the lacking of data from intermediate areas did not allow determining the entity and the nature of the observed discontinuity. In our study, in addition to a considerable number of individuals from Central and Northern Europe, Southern populations of Ixodes ricinus, sampled in Italy (Sicily) were included. These individuals belong to European group, hence marking the existence of an abrupt and strong genetic discontinuity. Several hypotheses had been proposed to explain this pattern. It could be linked to geographic discontinuity due to the presence of the Mediterranean sea separating the two continents. Anyway, the absence of discontinuity in the entire European continent and the possibility for I. ricinus to cover large distance feeding on migratory birds, might make questionable this hypothesis. Besides, there could be implicated ecological factors linked to I. ricinus biology and interactions with its hosts. Another hypothesis, not necessary excluding the previous ones, considers the role of interaction between species. Indeed, I. ricinus is a parasites and a vector of other parasites/pathogens, interacting both with its hosts and with the transmitted pathogens, and this fact might be the cause of the genetic difference in the two populations. All these selective pressures might have contributed to the insurgence of the observed differences between European and Tunisian populations of I. ricinus. Nuclear and mitochondrial loci are concordant in evidencing a genetic discontinuity between the two continents, but the two markers show different patterns. For mitochondrial DNA, no Tunisian haplotypes were encountered in Europe and vice versa. Nuclear loci show a degree of sharing of haplotypes of the two different haplogroups, probably due to long-distance migration of avian hosts. Further interesting ecological and evolutionary scenarios, in a speculative way, might be suggested to explain such differences. For example, genetic drift is able to drive the loss of genetic variants in a totally random process. The flux of haplotypes might involve not only nuclear genes, but also mitochondrial genes, but these ones are lost due to genetic drift that on this marker is stronger compared to nuclear loci. An alternative hypothesis proposes the existence of differential migration of males and females, where males do not transmit the mt genome. Indeed, females of I. ricinus resulted more philopatric compared to males and less incline to dispersion. Host preference with different dispersion capacity might explain this pattern, males tend to parasitize more often birds and females are more frequently encountered on large mammals. Another hypothesis might be linked to a selective disadvantage of females in the two geographic regions. In conclusion, the European population of I. ricinus does not present any phileogeographic structure. I would suggest that the pattern of low genetic diversity observed at nuclear and mitochondrial loci is a consequence of historical and contemporary factors. Both markers show traces of demographic expansion, in fact, mismatch distribution resulted unimodal and not deviate from the model expected in case of demographic expansion. Besides, the result is confirmed from the values of Fu\u2019s Fs index that are negative and significant. Over crossing the actual distribution of the species I. ricinus and the distribution of ice in glacial phases in European continent it is reasonable to suppose that the demographic expansion started from glacial refugia. The value of parameter \u3c4 of mismatch distribution of mitochondrial DNA, suggests that this expansion happened almost 20.000 years ago. Thus, evolutive event might be linked to deep climatic changes in temperate areas during glacial/interglacial phases in late Pleistocene. During this period, according to the general model of expansion/contraction, populations of thermophil species, like I. ricinus, to defend from ice advancing, moved to lower latitudinal refugia in suitable areas for survival, identified in the Southern Mediterranean peninsulae. In these refugia, various I. ricinus populations survived during glacial ages, and after ice melting and temperature rising, migrated to Northern areas. Previous studies on I. ricinus, hypothesized that this model, already validated for other species, is also valid for this parasite. But the results of this study suggest a different evolutive scenario. In fact, even if the genetic data support the hypothesis of an event of demographic and spatial expansion after glacial ages, on the contrary, the absence of different lineages localized inside the European continent, as the absence of a clinal variation of haplotypes frequencies do not support the glacial genetic fragmentation. The pattern observed is more adapted to explain a scenario were populations of I. ricinus remained inter-connected probably due to continuity offered by its multiple hosts, as suggested for other species with wide distribution in Western Paleartic (or we could even hypothesize that the species survived the glacial age into a single refugium). In the case of I ricinus is of fundamental importance to consider the ecological characteristics of the species in order to determine the response in front of the Pleistocenic climatic changes. The present analysis consents to evidence an historical component at the origin of actual pattern of distribution of genetic diversity, but also a variety of actual processes that acted on populations. The migration on long distances mediated by different I. ricinus hosts in different stages of its biological cycle might be implicated in the absence of correlation between genetic and geographic distances, the presence of haplotypes shared by populations distantly located and the lack of areas with major and minor diversity. On the contrary, the presence of specific and private haplotypes in areas in close vicinity suggests a restricted genetic flux on small geographic scale. The PCR screening for Borrelia burgdorferi sensu latu on ticks collected in Europe and North Africa allows to determine the presence of 4 species of borreliae causing human diseases (B. burgdorferi ss, B afzelii, B.garinii and B. lusitaniae) in the analyzed ticks. Due to the small number of individuals included in this study it was not possible to derive statistical correlations between the presence of spirochetes and specific mithocondrial or nuclear gene alleles (COI, COII; Defensin and Trospa). An interesting result of this study evidence that B. lusitaniae, a genospecies diffused in Portugal, Southern Spain and Northern Africa with a reduced distribution outside this areas, might be widely diffuse in other European countries (Italy and Czech Republic) and also in Turkey. Our analyses confirm that the genetic variability of I. ricinus in Continental Europe and in Northern Africa is limited. Correspondingly, the genetic variability of its principal endosymbiont Midichloria mitochondrii is also negligible. We suppose that this microorganism might have established the mutualistic association with I. ricinus only in recent times and probably experimented a recent increase in population size following the Paleocenic population expansion of its tick vector host. So far, this idea is not yet supported by proper investigation. M. mitochondrii was detected in various ticks species that could have acquired the bacteria during blood meal passing trough the infection of the host or during co-feeding on the vertebrate hosts (i.e. without the infection of the vertebrate). Besides, M. mitochondrii is present in several tick species apparently without remarkable variability (i.e., even identical 16s rDNA sequences are observed in different species), thus suggesting for M. mitochondrii the possibility to reach new hosts/vectors trough horizontal transmission. The presence of various 16S rDNA gene sequences with high similarity to that of M. mitochondrii in other Metazoa, including in environmental microbial mats suggests the existence of a family of Midichloria-like organisms (MLOs). Besides, the detection of DNA of MLOs in other hematophagous arthropods suggest a possibility of transmission and \u201ccirculation\u201d of these bacteria between vectors and vertebrate hosts. The lack of congruence between ticks and Midichloria bacteria phylogenies is a further indirect evidence of possible horizontal transmission. Even in the case of infection of the host, at present, there is no evidence supporting the pathogenic role of M. mitochondrii in vertebrates, but it is important to remind that several human mitochondrial dysfunction/pathologies are currently of unknown etiology. Our molecular screening in blood and tissues of vertebrates (including humans) detected 8 PCR positive blood samples from 4 horses (Equus caballus), 3 dogs (Canis familiaris) and 1 sheep (Ovis aries), out of a total of 293 mammalian blood samples examined. The sequences obtained were not identical; they showed high similarity with the 16S rDNA of MLOs detected in species different from I. ricinus. In these three years, my doctorate work on tick-borne pathogens (TBPs) contributed in providing new information on the presence of ticks and associated pathogenic microorganisms in Italian areas were knowledge were scanty, incomplete or obtained indirectly from hospitalized patients presenting clinical manifestations due to a specific TBD. In the framework of the investigation on tick-borne pathogens, I reported the presence of spirochetes of the species Borrelia afzelii, implicated in development of Lyme disease in humans, and B. lusitaniae, also suspected to be pathogenic for humans, in an highly populated area close to the industrial district of Milan (Ticino Park and surrounding area). This investigation allowed to describe human cases of borreliosis in a zone previously not consider at risk of tick infestation or endemic for Lyme disease. We also contributed in the process of valuation of the risk and management of the public health problem, providing correct information to clinicians, workers/tourists of the area exposed to the risk of tick-bite and defining the \u2018red\u2019 zones/hot spots at high risk where it is necessary to position informative signs on tick presence and tickborne diseases transmitted. Further study in the Ticino Park area detected the presence of Rickettsia monacensis and R. helvetica (both belonging to Spotted Fever Group-SFG rickettsiae) with high prevalence in Ixodes ricinus; and also the circulation of Francisella tularensis holartica (Type B) was reported. After this study, SFG rickettsi

Design and analysis of fractional factorial experiments from the viewpoint of computational algebraic statistics

We give an expository review of applications of computational algebraic statistics to design and analysis of fractional factorial experiments based on our recent works. For the purpose of design, the techniques of Gr\"obner bases and indicator functions allow us to treat fractional factorial designs without distinction between regular designs and non-regular designs. For the purpose of analysis of data from fractional factorial designs, the techniques of Markov bases allow us to handle discrete observations. Thus the approach of computational algebraic statistics greatly enlarges the scope of fractional factorial designs.Comment: 16 page

Inhibition, recovery and field responses of Astyanax fasciatus (Cuvier, 1819) brain cholinesterases upon exposure to azinphos-methyl

Pesticides used in agriculture are among the most important environmental pollutants. Organophosphate and carbamate insecticides, intensely used in deciduous fruit-trees, may be  transported to aquatic ecosystems by runoff. Northwest rural Montevideo possesses zones of fruit-tree farms, where azinphos-methyl is currently the most used pesticide. Despite the well-known neurotoxic properties of this agrochemical, studies of its effects on aquatic organisms are scarce in Uruguay. The main goal of this study was to evaluate effects on brain cholinesterases and erythrocyte micronuclei in Astyanax fasciatus exposed to azynphos-methyl in laboratory and field conditions. Dose-response curves showed concentration-dependent brain cholinesterase inhibitions and a LC50 (48-hour) of 2.31 mg L-1 for azinphos-methyl.  Fishes exposed for 48 hours to toxicant and then transferred to clear water recovered 80% of brain cholinesterase activity in 10 days. Field study indicated that A. fasciatus from a watershed with low contamination showed a brain cholinesterase specific activity of 62.2±5.1 Units.mg-1 protein (22ºC) 97.7 % of which was acetylcholinesterase. Specimens from a basin with intense fruticulture exhibited a spatial gradient: specimens collected downstream to the farms showed brain acetylcholinesterase activities 32% lower than fishes captured upstream. In conclusion, our data suggest that A. fasciatus is a suitable species for exotoxicological biomonitoring.Keywords: Acetylcholinesterase; Astyanax fasciatus; Aquatic Biomonitoring; Azinphos-methyl; Bioindicator; Brain cholinesterases; Fish; Organophosphate pesticide

The vanishing ideal of a finite set of points with multiplicity structures

Given a finite set of arbitrarily distributed points in affine space with arbitrary multiplicity structures, we present an algorithm to compute the reduced Groebner basis of the vanishing ideal under the lexicographic ordering. Our method discloses the essential geometric connection between the relative position of the points with multiplicity structures and the quotient basis of the vanishing ideal, so we will explicitly know the set of leading terms of elements of I. We split the problem into several smaller ones which can be solved by induction over variables and then use our new algorithm for intersection of ideals to compute the result of the original problem. The new algorithm for intersection of ideals is mainly based on the Extended Euclidean Algorithm.Comment: 12 pages,12 figures,ASCM 201

Algebraic generation of minimum size orthogonal fractional factorial designs: an approach based on integer linear programming

Generation of orthogonal fractional factorial designs (OFFDs) is an important and extensively studied subject in applied statistics. In this paper we show how searching for an OFFD that satisfies a set of constraints, expressed in terms of orthogonality between simple and interaction effects, is, in many applications, equivalent to solving an integer linear programming problem.We use a recent methodology, based on polynomial counting functions and strata, that represents OFFDs as the positive integer solutions of a system of linear equations. We use this system to set up an optimization problem where the cost function to be minimized is the size of the OFFD and the constraints are represented by the system itself. Finally we search for a solution using standard integer programming techniques. Some applications are also presented in the computational results section. It is worth noting that the methodology does not put any restriction either on the number of levels of each factor or on the orthogonality constraints and so it can be applied to a very wide range of designs, including mixed orthogonal array

Strain-induced magma degassing: insights from simple-shear experiments on bubble bearing melts

International audienceExperiments have been performed to determine the effect of deformation on degassing of bubble-bearing melts. Cylindrical specimens of phonolitic composition, initial water content of 1.5 wt.% and 2 vol.% bubbles, have been deformed in simple-shear (torsional configuration) in an internally heated Paterson-type pressure vessel at temperatures of 798-848 K, 100-180 MPa confining pressure and different final strains. Micro-structural analyses of the samples before and after deformation have been performed in two and three dimensions using optical microscopy, a nanotomography machine and synchrotron tomography. The water content of the glasses before and after deformation has been measured using Fourier Transform Infrared Spectroscopy (FTIR). In samples strained up to a total of γ ∼ 2 the bubbles record accurately the total strain, whereas at higher strains (γ ∼ 10) the bubbles become very flattened and elongate in the direction of shear. The residual water content of the glasses remains constant up to a strain of γ ∼ 2 and then decreases to about 0.2 wt.% at γ ∼ 10. Results show that strain enhances bubble coalescence and degassing even at low bubble volume-fractions. Noticeably, deformation produced a strongly water under-saturated melt. This suggests that degassing may occur at great depths in the volcanic conduit and may force the magma to become super-cooled early during ascent to the Earth's surface potentially contributing to the genesis of obsidian

Nonparametric Information Geometry

The differential-geometric structure of the set of positive densities on a given measure space has raised the interest of many mathematicians after the discovery by C.R. Rao of the geometric meaning of the Fisher information. Most of the research is focused on parametric statistical models. In series of papers by author and coworkers a particular version of the nonparametric case has been discussed. It consists of a minimalistic structure modeled according the theory of exponential families: given a reference density other densities are represented by the centered log likelihood which is an element of an Orlicz space. This mappings give a system of charts of a Banach manifold. It has been observed that, while the construction is natural, the practical applicability is limited by the technical difficulty to deal with such a class of Banach spaces. It has been suggested recently to replace the exponential function with other functions with similar behavior but polynomial growth at infinity in order to obtain more tractable Banach spaces, e.g. Hilbert spaces. We give first a review of our theory with special emphasis on the specific issues of the infinite dimensional setting. In a second part we discuss two specific topics, differential equations and the metric connection. The position of this line of research with respect to other approaches is briefly discussed.Comment: Submitted for publication in the Proceedings od GSI2013 Aug 28-30 2013 Pari

Coarse-grained entanglement classification through orthogonal arrays

Classification of entanglement in multipartite quantum systems is an open problem solved so far only for bipartite systems and for systems composed of three and four qubits. We propose here a coarse-grained classification of entanglement in systems consisting of $N$ subsystems with an arbitrary number of internal levels each, based on properties of orthogonal arrays with $N$ columns. In particular, we investigate in detail a subset of highly entangled pure states which contains all states defining maximum distance separable codes. To illustrate the methods presented, we analyze systems of four and five qubits, as well as heterogeneous tripartite systems consisting of two qubits and one qutrit or one qubit and two qutrits.Comment: 38 pages, 1 figur