Design and Performance of the CMS Pixel Detector Readout Chip

The readout chip for the CMS pixel detector has to deal with an enormous data rate. On-chip zero suppression is inevitable and hit data must be buffered locally during the latency of the first level trigger. Dead-time must be kept at a minimum. It is dominated by contributions coming from the readout. To keep it low an analog readout scheme has been adopted where pixel addresses are analog coded. We present the architecture of the final CMS pixel detector readout chip with special emphasis on the analog readout chain. Measurements of its performance are discussed.Comment: 8 pages, 11 figures. Contribution to the Proceedings of the Pixel2005 Workshop, Bonn, German

Occurrence and dynamics of potentially pathogenic vibrios in the wet-dry tropics of northern Australia

Bacteria from the Vibrio genus are a ubiquitous component of coastal and estuarine ecosystems with several pathogenic Vibrio species displaying preferences for warm tropical waters. We studied the spatial and temporal abundance of three key human potential pathogens V. parahaemolyticus, V. cholerae and V. vulnificus in northern tropical Australia, over the wet and dry seasons, to identify environmental parameters influencing their abundance. Quantitative PCR (qPCR) analysis revealed that V. parahaemolyticus occurred more frequently and in higher abundance than V. cholerae and V. vulnificus across all locations examined. All three species were more abundant during the wet season, with V. parahaemolyticus abundance correlated to temperature and conductivity, whereas nutrient concentrations and turbidity best explained V. vulnificus abundance. In addition to these targeted qPCR analyses, we assessed the composition and dynamics of the entire Vibrio community using hsp60 amplicon sequencing. Using this approach, 42 Vibrio species were identified, including a number of other pathogenic species such as V. alginolyticus, V. mimicus and V. fluvialis. The Vibrio community was more diverse in the wet season, with temperature and dissolved oxygen as the key factors governing community composition. Seasonal differences were primarily driven by a greater abundance of V. parahaemolyticus and V. vulnificus during the wet season, while spatial differences were driven by different abundances of V. harveyi, V. campbellii, V. cholerae and V. navarrensis. When we related the abundance of Vibrio to other bacterial taxa, defined using 16S rRNA gene amplicon sequencing, V. parahaemolyticus was negatively correlated to several taxa, including members of the Rickettsiales and Saccharimonadales, while V. vulnificus was negatively correlated to Rhobacteriaceae and Cyanobiaceae. In contrast, V. alginolyticus, V. harveyi and V. mediterranei were all positively correlated to Cyanobacteria. These observations highlight the dynamic nature of Vibrio communities and expands current understanding of the processes governing the occurrence of potentially pathogenic Vibrio spp. in tropical coastal ecosystems

Pearl Oyster Bacterial Community Structure Is Governed by Location and Tissue-Type, but Vibrio Species Are Shared Among Oyster Tissues.

Diseases of bivalves of aquacultural importance, including the valuable Australian silver-lipped pearl oyster (Pinctada maxima), have been increasing in frequency and severity. The bivalve microbiome is linked to health and disease dynamics, particularly in oysters, with putative pathogens within the Vibrio genus commonly implicated in oyster diseases. Previous studies have been biased toward the Pacific oyster because of its global dominance in oyster aquaculture, while much less is known about the microbiome of P. maxima. We sought to address this knowledge gap by characterizing the P. maxima bacterial community, and we hypothesized that bacterial community composition, and specifically the occurrence of Vibrio, will vary according to the sampled microenvironment. We also predicted that the inside shell swab bacterial composition could represent a source of microbial spillover biofilm into the solid pearl oyster tissues, thus providing a useful predictive sampling environment. We found that there was significant heterogeneity in bacterial composition between different pearl oyster tissues, which is consistent with patterns reported in other bivalve species and supports the hypothesis that each tissue type represents a unique microenvironment for bacterial colonization. We suggest that, based on the strong effect of tissue-type on the pearl oyster bacterial community, future studies should apply caution when attempting to compare microbial patterns from different locations, and when searching for disease agents. The lack of association with water at each farm also supported the unique nature of the microbial communities in oyster tissues. In contrast to the whole bacterial community, there was no significant difference in the Vibrio community among tissue types nor location. These results suggest that Vibrio species are shared among different pearl oyster tissues. In particular, the similarity between the haemolymph, inside shell and solid tissues, suggests that the haemolymph and inside shell environment is a source of microbial spillover into the oyster tissues, and a potentially useful tool for non-destructive routine disease testing and early warning surveillance. These data provide important foundational information for future studies identifying the factors that drive microbial assembly in a valuable aquaculture species

Identification of Burkholderia pseudomallei Near-Neighbor Species in the Northern Territory of Australia

Identification and characterization of near-neighbor species are critical to the development of robust molecular diagnostic tools for biothreat agents. One such agent, Burkholderia pseudomallei, a soil bacterium and the causative agent of melioidosis, is lacking in this area because of its genomic diversity and widespread geographic distribution. The Burkholderia genus contains over 60 species and occupies a large range of environments including soil, plants, rhizospheres, water, animals and humans. The identification of novel species in new locations necessitates the need to identify the true global distribution of Burkholderia species, especially the members that are closely related to B. pseudomallei. In our current study, we used the Burkholderia-specific recA sequencing assay to analyze environmental samples from the Darwin region in the Northern Territory of Australia where melioidosis is endemic. Burkholderia recA PCR negative samples were further characterized using 16s rRNA sequencing for species identification. Phylogenetic analysis demonstrated that over 70% of the bacterial isolates were identified as B. ubonensis indicating that this species is common in the soil where B. pseudomallei is endemic. Bayesian phylogenetic analysis reveals many novel branches within the B. cepacia complex, one novel B. oklahomensis-like species, and one novel branch containing one isolate that is distinct from all other samples on the phylogenetic tree. During the analysis with recA sequencing, we discovered 2 single nucleotide polymorphisms in the reverse priming region of B. oklahomensis. A degenerate primer was developed and is proposed for future use. We conclude that the recA sequencing technique is an effective tool to classify Burkholderia and identify soil organisms in a melioidosis endemic area

Comparison of TaqMan PCR assays for detection of the melioidosis agent Burkholderia pseudomallei in clinical specimens

Melioidosis is an emerging infectious disease caused by the soil bacterium Burkholderia pseudomallei. In diagnostic and forensic settings, molecular detection assays need not only high sensitivity with low limits of detection but also high specificity. In a direct comparison of published and newly developed TaqMan PCR assays, we found the TTS1-orf2 assay to be superior in detecting B. pseudomallei directly from clinical specimens. The YLF/BTFC multiplex assay (targeting the Yersinia-like fimbrial/Burkholderia thailandensis-like flagellum and chemotaxis region) also showed high diagnostic sensitivity and provides additional information on possible geographic origin

Comparison of TaqMan PCR assays for detection of the melioidosis agent Burkholderia pseudomallei in clinical specimens

Melioidosis is an emerging infectious disease caused by the soil bacterium Burkholderia pseudomallei. In diagnostic and forensic settings, molecular detection assays need not only high sensitivity with low limits of detection but also high specificity. In a direct comparison of published and newly developed TaqMan PCR assays, we found the TTS1-orf2 assay to be superior in detecting B. pseudomallei directly from clinical specimens. The YLF/BTFC multiplex assay (targeting the Yersinia-like fimbrial/Burkholderia thailandensis-like flagellum and chemotaxis region) also showed high diagnostic sensitivity and provides additional information on possible geographic origin

Analisis Kekuatan Massa Batugamping Dengan Menggunakan Kaidah Hoek-Brown Failure Criterion-Roclab Di Daerah Gunung Sudo Kabupaten Gunung Kidul YOGYAKARTA

The research area is a limestone quarry region prospect, located in Gunung Sudo, Gunung Kidul Regency, Special Region of Yogyakarta Province. Safety factor of bench in limestone quarry is extremely determined by rock mass quality. The aim of this research is analyzing of rock mass strength of limestone in the quarry prospect using the Hoek-Brown failure criterion. The research used quantitative method. To obtain rock mass strength analysis of limestone needs some parameters. The main parameters are uniaxial compressive strength of intact rock, GSI, lithology, disturbance factor, unit weight and application for slope (height).To solve this analysis is assisted by Roclab software. The Roclab is a software program for determining rock mass strength parameters based on the generalized Hoek-Brown failure criterion. Final result of the research will be used for safely mine design of the limestone quarry