Hydrometallurgy of the delta sulfide ores, second stage report

This report contains results of the Fluidized-Bed Leaching (FBL) initially adapted to improve Leaching-Flotation processing of Delta ores in sulfate solution. The research carried out in the continuous laboratory installation show, however, that the new, 3-phase (solid-liquid-gaseous) reactor also performs satisfactorily in other leaching systems. A new process of pyritic matrix destruction for precious metals recovery in the FBL reactor, and a new process for recovery of zinc and other metals in a chloride system are proposed on the basis of laboratory results.Submitted to: Nerco Minerals Compan

Isolement et étude d'une souche bactérienne transformant le phénol en benzoate en conditions anaérobies

Thèse numérisée par la Direction des bibliothèques de l'Université de Montréal

Mise en place d'un packaging 3D collectif de composants de puissance à structure verticale

International audienceNous présentons dans ce papier l'état d'avancement d'une approche d'assemblage collectif en 3D de modules électroniques de puissance, basée sur des étapes technologiques de fabrication à l'échelle de la plaque (200 mm de diamètre dans notre cas). Le concept repose sur l'intégration des étapes de packaging dans la fabrication front-end des composants. C'est une démarche globale de conception couplée composant-package. Cela inclut la conception des composants, les interconnexions, la fabrication et l'assemblage de toutes les parties. Les étapes spécifiques de fabrication de composants fonctionnels ainsi que celles conduisant à la réalisation d'un leadframe métallique sont décrites ici, comme des éléments clés de l'approche de packaging collectif de modules de puissance

Auditory Localization in Low-Bitrate Compressed Ambisonic Scenes

The increasing popularity of Ambisonics as a spatial audio format for streaming services poses new challenges to existing audio coding techniques. Immersive audio delivered to mobile devices requires an efficient bitrate compression that does not affect the spatial quality of the content. Good localizability of virtual sound sources is one of the key elements that must be preserved. This study was conducted to investigate the localization precision of virtual sound source presentations within Ambisonic scenes encoded with Opus low-bitrate compression at different bitrates and Ambisonic orders (1st, 3rd, and 5th). The test stimuli were reproduced over a 50-channel spherical loudspeaker configuration and binaurally using individually measured and generic Head-Related Transfer Functions (HRTFs). Participants were asked to adjust the position of a virtual acoustic pointer to match the position of virtual sound source within the bitrate-compressed Ambisonic scene. Results show that auditory localization in low-bitrate compressed Ambisonic scenes is not significantly affected by codec parameters. The key factors influencing localization are the rendering method and Ambisonic order truncation. This suggests that efficient perceptual coding might be successfully used for mobile spatial audio delivery

Morphological characters of immature stages of Palaearctic species of Cleopomiarus and Miarus and their systematic value in Mecinini (Coleoptera, Curculionidae, Curculioninae)

The relationship between the genera Cleopomiarus and Miarus of Mecinini (Curculionidae, Curculioninac) was tested on the basis of morphological characters from the immature stages. The mature larvae of five Cleopomiarus species (C. distinctus (Boheman, 1845), C. graminis (Gyllenhal, 1813), C. longirostris (Gyllenhal, 1838), C. medius (Desbrochers des Loges, 1893), and C. meridionalis (H. Brisout de Barneville, 1863)), three Miarus species (M. abnormis Solari, 1947, M. ajugae (Herbst, 1795), and M. campanulae (Linnaeus, 1767)), and the pupae of four Cleopomiarus species (C. distinct us, C. graminis, C. longirostris, and C. medius) and two Miarus species (M. abnormis and M. ajugae) are described in detail for the first time. To confirm the taxonomic identification of some larvae, DNA COI barcode was obtained and compared with those of adults. The immature stages of the species herein studied were compared with those known from other genera in tribe Mecinini. It is suggested that Miarus and Cleopomiarus may be monophyletic based on several shared distinctive characters. Larvae of Miarus have a characteristic maxil-lary mala with six finger-like dms of two sizes (one or two elms very long and the rest of medium length), this feature being apparently unique among weevils. Other genus-specific character states are observed in the pupae, such as the length of setae on the head, rostrum and pronotum, including the number of rs on the rostrum, ds on pronotum, and finally the shape of the urogomphi. A key to the described larvae and pupae were respectively presented. New biological and distributional data on some species are reported

Physico-chemical foundations underpinning microarray and next-generation sequencing experiments

Hybridization of nucleic acids on solid surfaces is a key process involved in high-throughput technologies such as microarrays and, in some cases, next-generation sequencing (NGS). A physical understanding of the hybridization process helps to determine the accuracy of these technologies. The goal of a widespread research program is to develop reliable transformations between the raw signals reported by the technologies and individual molecular concentrations from an ensemble of nucleic acids. This research has inputs from many areas, from bioinformatics and biostatistics, to theoretical and experimental biochemistry and biophysics, to computer simulations. A group of leading researchers met in Ploen Germany in 2011 to discuss present knowledge and limitations of our physico-chemical understanding of high-throughput nucleic acid technologies. This meeting inspired us to write this summary, which provides an overview of the state-of-the-art approaches based on physico-chemical foundation to modeling of the nucleic acids hybridization process on solid surfaces. In addition, practical application of current knowledge is emphasized

Multi-stringency wash of partially hybridized 60-mer probes reveals that the stringency along the probe decreases with distance from the microarray surface

Here, we describe a multi-parametric study of DNA hybridization to probes with 20–70% G + C content. Probes were designed towards 71 different sites/mutations in the phenylalanine hydroxylase gene. Seven probe lengths, three spacer lengths and six stringencies were systematically varied. The three spacer lengths were obtained by placing the gene-specific sequence in discrete steps along the 60-mer probes. The study was performed using Agilent 8 × 15 000 probes custom-made arrays and a home-built array washer providing different stringencies to each of the eight sub-arrays on the slides. Investigation of hybridization signals, specificity and dissociation curves indicated that probes close to the surface were influenced by an additional stringency provided by the microarray surface. Consistent with this, probes close to the surface required 4 × SSC, while probes placed away from the surface required 0.35 × SSC wash buffers in order to give accurate genotyping results. Multiple step dissociation was frequently observed for probes placed furthest away from surface, but not for probes placed proximal to the surface, which is consistent with the hypothesis that there is different stringency along the 60-mer. The results have impact on design of probes for genotyping, gene expression and comparative genome hybridization analysis

Investigating the global genomic diversity of Escherichia coli using a multi-genome DNA microarray platform with novel gene prediction strategies

<p>Abstract</p> <p>Background</p> <p>The gene content of a diverse group of 183 unique <it>Escherichia coli </it>and <it>Shigella </it>isolates was determined using the Affymetrix GeneChip^®<it>E. coli </it>Genome 2.0 Array, originally designed for transcriptome analysis, as a genotyping tool. The probe set design utilized by this array provided the opportunity to determine the gene content of each strain very accurately and reliably. This array constitutes 10,112 independent genes representing four individual <it>E. coli </it>genomes, therefore providing the ability to survey genes of several different pathogen types. The entire ECOR collection, 80 EHEC-like isolates, and a diverse set of isolates from our FDA strain repository were included in our analysis.</p> <p>Results</p> <p>From this study we were able to define sets of genes that correspond to, and therefore define, the EHEC pathogen type. Furthermore, our sampling of 63 unique strains of O157:H7 showed the ability of this array to discriminate between closely related strains. We found that individual strains of O157:H7 differed, on average, by 197 probe sets. Finally, we describe an analysis method that utilizes the power of the probe sets to determine accurately the presence/absence of each gene represented on this array.</p> <p>Conclusions</p> <p>These elements provide insights into understanding the microbial diversity that exists within extant <it>E. coli </it>populations. Moreover, these data demonstrate that this novel microarray-based analysis is a powerful tool in the field of molecular epidemiology and the newly emerging field of microbial forensics.</p