Inverse design of cooperative electromagnetic interactions

The cooperative electromagnetic interactions between discrete resonators have been widely used to modify the optical properties of metamaterials. Here we propose a general evolutionary approach for engineering these interactions in arbitrary networks of resonators. To illustrate the performances of this approach, we designed by genetic algorithm, an almost perfect broadband absorber in the visible range made with a simple binary array of metallic nanoparticles

Formal Executable Models for Automatic Detection of Timing Anomalies

A timing anomaly is a counterintuitive timing behavior in the sense that a local fast execution slows down an overall global execution. The presence of such behaviors is inconvenient for the WCET analysis which requires, via abstractions, a certain monotony property to compute safe bounds. In this paper we explore how to systematically execute a previously proposed formal definition of timing anomalies. We ground our work on formal designs of architecture models upon which we employ guided model checking techniques. Our goal is towards the automatic detection of timing anomalies in given computer architecture designs

A Monte-Carlo Method For Score Normalization in Automatic Speaker Verification Using Kullback-Leibler Distances

In this paper, we propose a new score normalization technique in Automatic Speaker Verification (ASV): the D-Norm. The main advantage of this score normalization is that it does not need any additional speech data nor external speaker population, as opposed to the state-ofthe-art approaches. The D-Norm is based on the use of Kullback-Leibler (KL) distances in an ASV context. In a first step, we estimate the KL distances with a Monte-Carlo method and we experimentally show that they are correlated with the verification scores. In a second step, we use this correlation to implement a score normalization procedure, the D-Norm. We analyse its performance and we compare it to that of a conventional normalization, the Z-Norm. The results show that performance of the D-Norm is comparable to that of the Z-Norm. We then conclude about the results we obtain and we discuss the applications of this work.

Identification and partial characterization of antifungal and antibacterial activities of two Bacillus sp. strains isolated from salt soil in Tunisia

Two Bacillus sp. strains (B29 and B27) isolated from soil in the South of Tunisia were tested for their abilities to produce antimicrobial compounds. Both strains showed antimicrobial activity against Gram-positive and Gram-negative bacteria, yeasts and fungi. The produced compounds were extracted by using four different solvents. The hexane solvent allowed to obtain maximum of activity of the strain B29. The activity of the strain B27 was not elucidated by the four solvents used. Bio-autography results of B29 hexane extract revealed presence of different antibiotics and antifungal compounds with different Rf values of 0.3 and 0.76 for antifungal compounds and of 0.12, 0.14, 0.19 and 0.3 for antibacterial ones. Two active fractions were isolated from the culture broth of the strain B29 by semi-preparative high performance liquid chromatography (HPLC). The partial sequencing of the 16S rDNA gene was used to identify the two Bacillus strains. They may be assigned to new Bacillus specie

Unsupervised mining of audiovisually consistent segments in videos with application to structure analysis

International audienceIn this paper, a multimodal event mining technique is proposed to discover repeating video segments exhibiting audio and visual consistency in a totally unsupervised manner. The mining strategy first exploits independent audio and visual cluster analysis to provide segments which are consistent in both their visual and audio modalities, thus likely corresponding to a unique underlying event. A subsequent modeling stage using discriminative models enables accurate detection of the underlying event throughout the video. Event mining is applied to unsupervised video structure analysis, using simple heuristics on occurrence patterns of the events discovered to select those relevant to the video structure. Results on TV programs ranging from news to talk shows and games, show that structurally relevant events are discovered with precisions ranging from 87% to 98% and recalls from 59% to 94%

Taxonomy and antimicrobial activities of a new Streptomyces sp. TN17 isolated in the soil from an oasis in Tunis

An actinomycete strain referred to as TN17 was screened for its antimicrobial activities. The taxonomic status of this strain was established. The organism was found to have morphological and chemotaxonomic characteristics typical of Streptomycetes. Based on the 16S rRNA nucleotide sequences, Streptomyces sp. TN17 was found to have a relationship with Streptomyces lilaceus, Streptomyces gobitricini and Streptomyces lavendofoliae. Combined analysis of the 16 S rRNA gene sequence (FN687757), phylogenetic analysis, fatty acids profile and physiological tests indicated that there are genotypic and phenotypic differences between TN17 and neighboring Streptomyces species’ neighbors. Therefore, TN17 is a novel species: Streptomyces sp. TN17 (=DSM 42020T=CTM50229T). A cultured extract of this strain inhibits the growth of several Gram positive and Gram negative bacteria and fungi

Characterizing Modular Ontologies

International audienceSince large monolithic ontologies are di cult to handle and reuse ontology modularization has attracted increasing attention. Several approaches and tools have been developed to support ontology modularization. Despite these e orts, a lack of knowledge about characteristics of modularly organized ontologies prevents further development. This work aims at characterizing modular ontologies. Therefore, we analyze existing modular ontologies by applying selected metrics from software engineering in order to identify recurring structures, i.e. patterns in modularly organized ontologies. The contribution is a set of four patterns which characterize modularly organized ontologies

Quenched invariance principle for random walks in balanced random environment

We consider random walks in a balanced random environment in $\mathbb{Z}^d$, $d\geq 2$. We first prove an invariance principle (for $d\ge2$) and the transience of the random walks when $d\ge 3$ (recurrence when $d=2$) in an ergodic environment which is not uniformly elliptic but satisfies certain moment condition. Then, using percolation arguments, we show that under mere ellipticity, the above results hold for random walks in i.i.d. balanced environments.Comment: Published online in Probab. Theory Relat. Fields, 05 Oct 2010. Typo (in journal version) corrected in (26

Purification and structure elucidation of three naturally bioactive molecules from the new terrestrial Streptomyces sp. TN17 strain

Thirty litres of fermentation broth was extracted from the newly isolated Streptomyces sp. strain TN17 and various separation and purification steps led to the isolation of three pure bioactive compounds (1–3). Compound 1: cyclo (L-Leu-L-Arg), a diketopiperazine ‘DKP’ derivative; 2: di-(2-ethylhexyl) phthalate, a phthalate derivative; and 3: cyclo 1-[2-(cyclopentanecarbonyl-3-phenyl-propionyl]-pyrrolidine-2-carboxylic acid (1-carbamoyl-propyl)-amide, a cyclic tetrapeptide derivative. The chemical structure of these three active compounds was established on the basis of spectroscopic studies (MS and NMR) and by comparison with data from the literature. According to our biological studies, the pure compounds (1–3) possess antibacterial and antifungal activities

Beef value chain analysis in Zimbabwe

Conducted between September 2017 and April 2018, this analysis of the Zimbabwe beef value chain addressed the questions: What is the contribution of the value chain to economic growth? Is the economic growth generated by the value chain inclusive? Is the value chain socially sustainable? and, Is the value chain environmentally sustainable? The historical background for the Zimbabwe beef value chain is important as it provides context for the current situation. During the colonial and post-colonial period the key objective for the beef sector was intensive commercial farming and exploitation of market access opportunities under the Lome Convention. Following this Zimbabwe underwent a period of intensive land reform with large-scale transfer of farm land from Commercial (white) farmers to small-scale (black) farmers. Somewhere between 161,500 and 300,000 households have resettled on about 4.9 million hectares (Scoones et al, 2010). Commercial farms (white) have declined from 4,000 to about 725. However, various categories of 'new' (black) commercial farms have been developed pre-and post-land reform (11,000+ households). During this period the national disease control system failed and exports ended. Causes of this collapse include: co-habitation of buffalo and cattle; and, un-restrained movement of cattle from high-risk areas. Illegal exports and imports are also reported. Currently, Zimbabwe aims to reinstate centralised veterinary control to manage transboundary diseases. This has, so far, been unsuccessful with regular outbreaks of food-and-mouth disease occurring, including during the period of this research. A high proportion of the Zimbabwe population is poor (72.3%) and extremely poor (16.2%). Malnutrition affects 33.8% of children between 6-59 months of age. Rural Zimbabwe is poorer than urban areas by some margin (30.4% of households are extremely poor in rural areas vs 5.6% in urban areas). This drives migration and emigration. Livestock are essential for resilience and coping; cattle holding and maize yields closely correlated. Farms without livestock are the most vulnerable. Beef consumption is declining: from 13kg to 4 or 6kg per capita reflecting income changes and the availability of cheap chicken meat. Zimbabwe is a semi-arid country with 85% of the area receiving less than 800mm of rain a year. Resource endowment is high, but distribution skewed and sustainability is questioned by many. Key environmental issues include: land degradation, largely through poor land management; deforestation, through land clearance and fuel use; water scarcity, due to over extraction and urbanisation; pollution of water and air, through mining, urbanisation and intensive agriculture; biodiversity loss, through agricultural expansion and habitat loss; and, climate change and variability, resulting in higher temperatures and lower/variable rainfall