Clones in Graphs

Finding structural similarities in graph data, like social networks, is a far-ranging task in data mining and knowledge discovery. A (conceptually) simple reduction would be to compute the automorphism group of a graph. However, this approach is ineffective in data mining since real world data does not exhibit enough structural regularity. Here we step in with a novel approach based on mappings that preserve the maximal cliques. For this we exploit the well known correspondence between bipartite graphs and the data structure formal context $(G,M,I)$ from Formal Concept Analysis. From there we utilize the notion of clone items. The investigation of these is still an open problem to which we add new insights with this work. Furthermore, we produce a substantial experimental investigation of real world data. We conclude with demonstrating the generalization of clone items to permutations.Comment: 11 pages, 2 figures, 1 tabl

Vietnamese chickens: a gate towards Asian genetic diversity

BACKGROUND: Chickens represent an important animal genetic resource and the conservation of local breeds is an issue for the preservation of this resource. The genetic diversity of a breed is mainly evaluated through its nuclear diversity. However, nuclear genetic diversity does not provide the same information as mitochondrial genetic diversity. For the species Gallus gallus, at least 8 maternal lineages have been identified. While breeds distributed westward from the Indian subcontinent usually share haplotypes from 1 to 2 haplogroups, Southeast Asian breeds exhibit all the haplogroups. The Vietnamese Ha Giang (HG) chicken has been shown to exhibit a very high nuclear diversity but also important rates of admixture with wild relatives. Its geographical position, within one of the chicken domestication centres ranging from Thailand to the Chinese Yunnan province, increases the probability of observing a very high genetic diversity for maternal lineages, and in a way, improving our understanding of the chicken domestication process. RESULTS: A total of 106 sequences from Vietnamese HG chickens were first compared to the sequences of published Chinese breeds. The 25 haplotypes observed in the Vietnamese HG population belonged to six previously published haplogroups which are: A, B, C, D, F and G. On average, breeds from the Chinese Yunnan province carried haplotypes from 4.3 haplogroups. For the HG population, haplogroup diversity is found at both the province and the village level (0.69).The AMOVA results show that genetic diversity occurred within the breeds rather than between breeds or provinces. Regarding the global structure of the mtDNA diversity per population, a characteristic of the HG population was the occurrence of similar pattern distribution as compared to G. gallus spadiceus. However, there was no geographical evidence of gene flow between wild and domestic populations as observed when microsatellites were used. CONCLUSIONS: In contrast to other chicken populations, the HG chicken population showed very high genetic diversity at both the nuclear and mitochondrial levels. Due to its past and recent history, this population accumulates a specific and rich gene pool highlighting its interest and the need for conservation

A new multimethod approach for dating cave calcite: application to the cave of Trou du Renard (Soyons, France)

A multimethod approach aimed at characterizing carbonate parietal deposits and at proposing a chronology for these carbonate crusts is described. Dating was performed by radiometric methods (C-14 for recent samples and U series) on samples that had been characterized beforehand using optical and cathodoluminescence microscopy and Fourier transform infrared microspectroscopy. For the U series, high precision on U–Th ages was achieved using liquid phase multicollector inductively coupled plasma mass spectrometry (ICP-MS) applied to large samples, while laser ablation single collector inductively coupled plasma sector field mass spectrometry (ICP-SFMS) provided information on the reliability of the sampling with a high spatial resolution. This methodology, based on the combination of these two techniques reinforced by the information obtained by the calcite characterization methods, was applied to carbonate deposits from the cave of Trou du Renard (Soyons, France). The ages obtained with the two U–Th dating techniques are comparable and illustrate that different laminae were deposited at different rates in the samples. In the future, this procedure, based on the mineralogical and geochemical characterization of the samples and their dating by radiometric methods, will be applied to the layers of parietal carbonates deposited on Palaeolithic decorated walls. When the crystallization is slow, the U/Th dating method by imaging technique is of interest, as well as that by multicollector ICP-MS in liquid phase. The development of robust dating methods on very small quantities of material will make it possible to define the chronological framework of cave rock art.</p

ETUDE DU BRUIT ENGENDRÉ PAR L'IMPACT D'UN JET SUPERSONIQUE CHAUD SUR UN OBSTACLE

Une étude expérimentale du bruit engendré par l'interaction d'un jet supersonique chaud avec un obstacle est présentée. La caractérisation des sources de bruit a été effectuée par des mesures de directivités en champ lointain, des mesures de puissance acoustique rayonnée et des localisations de sources par réseau de capteurs. L'introduction d'un obstacle dans un jet entraîne une élévation des niveaux sonores dans la partie de l'espace en amont de l'obstacle. La localisation de sources a montré que les sources de bruit prépondérantes sont situées dans la zone d'interaction. Cependant, l'apparition de ces sources ne se traduit pas par une augmentation importante de la puissance rayonnée.This document presents experimental works on supersonic hot jet impingement noise which have been done in an anechoic wind tunnel. Far field noise directivity measurements were done for a supersonic jet impingement on an axisymmetric obstacle. Source localizations with focused microphone arrays were realized simultaneously. Introduction of a board in a jet increases the sound pressure level upstream of the board. The localizations with focused microphone arrays show that the predominant sources of noise are located near the impingement region. However, this apparition of sound sources does not amount to a large increase of the total sound power level

Opérations d’archéologie préventive dans la plaine de Vallon Pont d’Arc

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Comparison of toxicokinetic properties of eleven analogues of Bisphenol A in pig after intravenous and oral administrations

Due to the restrictions of its use, Bisphenol A (BPA) has been replaced by many structurally related bisphenols (BPs) in consumer products. The endocrine disrupting potential similar to that of BPA has been described for several bisphenols, there is therefore an urgent need of toxicokinetic (TK) data for these emerging BPs in order to evaluate if their internal exposure could increase the risk of endocrine disruption. We investigated TK behaviors of eleven BPA substitutes (BPS, BPAF, BPB, BPF, BPM, BPZ, 3-3BPA, BP4-4, BPAP, BPP, and BPFL) by intravenous and oral administrations of mixtures of them to piglets and serial collection of blood over 72 h and urine over 24 h, to evaluate their disposition. Data were analyzed using nonlinear mixed-effects modeling and a comparison was made with TK predicted by the generic model HTTK package. The low urinary excretion of some BPs, in particular BPM, BPP and BPFL, is an important aspect to consider in predicting human exposure based on urine biomonitoring. Despite their structural similarities, for the same oral dose, all BPA analogues investigated showed a higher systemic exposure (area under the plasma concentration-time curve (AUC) of the unconjugated Bisphenol) than BPA (2 to 4 fold for 3-3BPA, BPAF, BPB and BPZ, 7–20 fold for BP4-4, BPAP, BPP, BPFL, BPF and BPM and 150 fold for BPS) due mainly to a considerable variation of oral bioavailability (proportion of BP administered by oral route that attains the systemic circulation unchanged). Given similarities in the digestive tract between pigs and humans, our TK data suggest that replacing BPA with some of its alternatives, particularly BPS, will likely lead to higher internal exposure to potential endocrine disruptive compounds. These findings are crucial for evaluating the risk of human exposure to these emerging BPs

Redox behavior of a ferrocene monolayer on SiO2 obtained after click-coupling

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