Molecular analysis of microbial diversity within Yucca Mountain

Yucca Mountain is the proposed site for a high-level nuclear waste repository. As part of the site characterization project, an estimation of microbial diversity was conducted. In this study, the 16S ribosomal DNA sequences of culturable isolates were determined and used for tentatively identification of bacterial strains. The results of identification by 16S rDNA sequence data were also compared to MIDI analysis, an independent phenotypic approach for bacterial identification; It is accepted that culturable strains only represent a small portion of microbial community in the environment. In order to eliminate bias associated with cultivation, total DNA was extracted from rock samples and subjected to 16S rDNA analysis. 16S rDNAs were amplified from the total DNA pool and cloned. Each cloned fragment in the constructed clone library was then subjected to sequence determination. Microbial diversity derived from total extracted DNA demonstrated a different vision of diversity from culturable isolates within Yucca Mountain; Two sample sites with different geology and geochemistry were selected for analysis. While culturable isolates contained mostly gram positive bacteria, gram negative bacteria in this environment were more dominant by DNA analysis. One study site, YM9, contained 100% of gram negative bacteria by total DNA analysis, with 89% being Pseudomonas species; In order to estimate the reliability of bacterial diversity derived from a series of molecular analyses as a whole, 10 common soil bacteria were seeded into sterile rock and subjected to the same process of sample analysis. The process showed no significant preference when interpreting the major group of gram positive and gram negative bacteria. Pseudomonas, represented by three species in the seeded sample, was not favored by the process. The presence of Pseudomonas species in this environment may be even higher than we detected; The detection of genetic diversity within a natural environment can be considered the very first step towards understanding the role that bacteria play in an ecosystem. The identity of major bacterial populations in Yucca Mountain will be important for development of strategies for storage of high-level nuclear waste and the maintenance of the repository integrity

Heritage Conservation and Urban Landscaping of Ancient Pan Pool Neighborhood, Qufu: a Historical and Indigenous Perspective

Gu Pan Pool neighborhood got its name because of Gu Pan Chi, (古泮池，the ancient Pan Pool), located in the southeastern part of Confucius’ birthplace, Qufu, the birth place of Confucius with a history of 3000 year. Gu Pan Pool has been recently under preservation with the joint efforts of World Bank cultural heritage conservation project and the local municipal government. With disparate interests in mind, the three stakeholders of heritage, the world bank, Qufu municipal government and local residents are contradictory with each other in the regeneration process, in which the local voices are often ignored. The purpose of this paper is to rethink heritage making from a historical and indigenous perspective in the contemporary Chinese urban historic landscape planning process. The author contends that the cultural value and pluralism embedded in the ritual way of thinking in Chinese Classics inherited and transmitted for thousands of years could be an alternative way of thinking for the landscape planning practices in the homogenizing culture of global capitalism. This research aims to reinterpret and re-activate Confucianism as cultural heritage to enrich the understanding and hence the sustainability related to human action in urban spaces with emphasis on planning processes in contemporary China

A rank based metric of anchor models for speaker verification

In this paper, we present an improved method of anchor models for speaker verification. Anchor model is the method that represent a speaker by his relativity of a set of other speakers, called anchor speakers. It was firstly introduced for speaker indexing in large audio database. We suggest a rank based metric for the measurement of speaker character vectors in anchor model. Different from conventional metric methods which consider each anchor speaker equally and compare the log likelihood scores directly, in our method the relative order of anchor speakers is exploited to characterize target speaker. We have taken experiments on the YOHO database. The results show that EER of our method is 13.29 % lower than that of conventional metric. Also, our method is more robust against the mismatching between test set and anchor set. 1

Frequency Shifting for Emotional Speaker Recognition

Non

Identification and bioinformatic analysis of the membrane proteins of synechocystis sp. PCC 6803

© 2009 Wang et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens

Change of evaporation rate of single monocomponent droplet with temperature using time-resolved phase rainbow refractometry

International audienc

Genetic Diversity of Salmonella enteric serovar Typhi and Paratyphi in Shenzhen, China from 2002 through 2007

<p>Abstract</p> <p>Background</p> <p>Typhoid and paratyphoid fever are endemic in China. The objective of this investigation was to determine the molecular features of nalidixic acid-resistant <it>Salmonella enteric </it>serovar Typhi (<it>S. typhi</it>) and Paratyphi (<it>S. paratyphi</it>) from blood isolates in Shenzhen, China.</p> <p>Results</p> <p>Twenty-five <it>S. typhi </it>and 66 <it>S. paratyphi </it>were isolated from 91 bacteriemic patients between 2002 and 2007 at a hospital in Shenzhen, Southern China. Fifty-two percent (13/25) of <it>S. typhi </it>and 95.3% (61/64) of <it>S. paratyphi </it>A were resistant to nalidixic acid. Sixty-seven isolates of nalidixic acid-resistant <it>Salmonella </it>(NARS) showed decreased susceptibility to ciprofloxacin (MICs of 0.125-1 μg/mL). All 75 NARS isolates had a single substitution in the quinolone resistance-determining region (QRDR) of GyrA (Ser83→Phe/Pro/Tyr, or Asp87→Gly/Asn), and 90.7% of these isolates carried the substitution Ser83Phe in GyrA. No mutation was found in the QRDR of <it>gyrB</it>, <it>parC</it>, or <it>parE</it>. Plasmid mediated quinolone resistance genes including <it>qnr </it>and <it>aac(6')-Ib-cr </it>were not detected in any isolate. Twenty-two distinct pulsed field gel electrophoresis (PFGE) patterns were observed among <it>S. typhi</it>. Sixty-four isolates of <it>S. paratyphi </it>A belonged to one clone. Eighty-seven investigated inpatients were infected in the community. Six patients infected by <it>S. paratyphi </it>A had a travel history before infection.</p> <p>Conclusions</p> <p>Nalidixic acid-resistant <it>S. typhi </it>and <it>S. paratyphi </it>A blood isolates were highly prevalent in Shenzhen, China. PFGE showed the variable genetic diversity of nalidixic acid-resistant <it>S. typhi </it>and limited genetic diversity of nalidixic acid -resistant <it>S. paratyphi </it>A.</p