MIX-crowds, an anonymity scheme for file retrieval systems

In this paper, we propose an anonymous scheme for file retrieval systems, MIX-Crowds, in which it is harder for an attacker to identify the requester of the file by making use of the idea of MIX [7] and Crowds [20] to establish a path from the requester to the file holder. Result shows that predecessor attack [26] is much more difficult to succeed compared with Crowds [20]. We are able to reduce the estimated number of rounds needed for successful predecessor attack for MIX-Crowds. We also propose a file transfer strategy according to file size. With such strategy, requests for small size files can be completed faster while the downloading time of large size files only increases slightly. © 2009 IEEE.published_or_final_versionThe 28th International Conference on Computer Communications (IEEE INFOCOM 2009), Rio de Janeiro, Brazil, 19-25 April 2009. In Proceedings of the IEEE Infocom, 2009, p. 1170-117

Chemical Printing of Biological Tissue by Gold Nanoparticle-Assisted Laser Ablation

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Optical characteristics of GAN/SI micro-pixel light-emitting diode arrays

Two-dimensional arrays of emissive micro-light-emitting diodes (μ-LEDS) have been developed for a variety of applications such as high resolution micro-displays, maskless photo-lithography and multichannel visible-light optical communications amongst others. μ-LEDs have traditionally been fabricated on InGaN LED wafers grown on transparent sapphire substrates, and have suffered from optical crosstalk issues. When a single pixel is addressed, adjacent pixels and regions appear illuminated simultaneously. Such problems could result in functional failure in high-density μ-LED applications, including reduced resolution of micro-display and decreased signal-to-noise ratio in ...postprin

Automated adaptive analysis of tagged magnetic resonance images of the mouse heart

The full potential of tagged MRI of the mouse heart for non-invasive evaluation of cardiac mechanics in transgenic animals has not been realized due to excessive user involvement with available image processing algorithms. Therefore, we developed an automated, rapid, high-resolution analysis technique, called High Density Mapping (HDM), that uses spectral correlation to efficiently quantify regional wall deformation, does not entail tracking of individual tags, and involves minimal user interaction. HDM analysis distinguishes regional mechanics in healthy and infarcted mice within 2 minutes. This new method may help promote the practical use of tagged MRI in mice and other species.published_or_final_versio

Human papillomavirus-16/18 AS04-adjuvanted cervical cancer vaccine: Immunogenicity and safety in healthy Chinese women from Hong Kong

Objective To assess the immunogenicity and safety of human papillomavirus-16/18 AS04-adjuvanted cervical cancer vaccine in Chinese women aged 18 to 35 years enrolled from Hong Kong. Design Double-blind, randomised controlled trial with vaccine and placebo groups. Setting Single-centre study in Hong Kong. Participants Three hundred women enrolled (150 per group) between March 2006 and June 2007. Interventions Subjects received three doses of human papillomavirus-16/18 vaccine or placebo (aluminium hydroxide), administered intramuscularly at 0, 1, and 6 months. Main outcome measures Human papillomavirus-16/18 seroconversion rates and geometric mean titres at month 7 (in human papillomavirus-16/18 recipients); reactogenicity and safety (in all subjects). Results A total of 294 women completed the study (148 in the vaccine group, 146 in placebo group). All initially seronegative subjects in the vaccine group had seroconverted for human papillomavirus-16/18 antibodies by month 7. Anti-human papillomavirus-16 and anti-human papillomavirus-18 antibody geometric mean titres were 10 422 (95% confidence interval, 8730-12 442) EL.U/mL and 4649 (3975-5437) EL.U/mL, respectively. High compliance (99% in both groups) was observed for the three-vaccination course. The frequencies of local injection site reactions were higher in the vaccine than placebo group; pain being the most common symptom in both groups. Regarding solicited symptoms, fatigue and myalgia were the most frequent in both groups. Five serious adverse events (four in vaccine group, one in placebo group) were reported, but all were considered unrelated to the vaccinations. Conclusion The human papillomavirus-16/18 AS04-adjuvanted vaccine was highly immunogenic, safe, and generally well tolerated in Chinese women from Hong Kong.published_or_final_versio

Tectonic affinity of the west Qinling terrane (central China): North China or Yangtze?

[33] Neogene (̃14 Ma) basaltic magmatism has occurred in west Qinling, at the northeastern corner of the Tibetan Plateau. Furthermore, U-Pb ages and Hf isotopic data of xenocrystic zircons indicate that the unexposed Neoarchean (2.7-2.5 Ga) basement beneath the Phanerozoic outcrops in west Qinling has affinities with the southern margin of the north China block. The basement has a complex evolution, including the addition of juvenile mantle material at ̃2.7- 2.4 Ga and 1.1-0.8 Ga and reworking at ̃1.8 Ga and possibly at 1.4 Ga. Phanerozoic thermal events at 320-300 Ma, 230 Ma, and 160 Ma also have affected the basement. We interpret the west Qinling orogenic terrane as originally separated from the north China block, joined to the northern Yangtze block during the Meso-Neoproterozoic, and finally involved in the northward subduction and collision of the Yangtze block in the Paleozoic and early Mesozoic and subsequent lithospheric extension in the Jurassic. © 2010 by the American Geophysical Union.published_or_final_versio

Case study on the efficacy of a lanthanum-enriched clay (Phoslock®) in controlling eutrophication in Lake Het Groene Eiland (The Netherlands)

Lake Het Groene Eiland was created in the beginning of 2008 by construction of dikes for isolating it from the surrounding 220-ha water body. This so-called claustrum of 5 ha was treated using lanthanum-modified clay (Phoslock®) to control eutrophication and mitigate cyanobacterial nuisance. Cyanobacteria chlorophyll-a were significantly lower in the claustrum than those in the reference water body, where a massive bloom developed in summer, 2008. However, PO4-P and TP did not statistically differ in these two waters. TN and NO3-N were significantly lower in the claustrum, where dense submerged macrophytes beds developed. Lanthanum concentrations were elevated after the applications of the modified clay in the claustrum, but filterable lanthanum dropped rapidly below the Dutch standard of 10.1 μg l−1. During winter, dozens of Canada geese resided at the claustrum. Geese droppings contained an average of 2 mg PO4-P g−1 dry weight and 12 mg NH3-N g−1 dry weight and might present a growing source of nutrients to the water. Constructing the claustrum enabled unrestricted bathing in subsequent three summers, as no swimming bans had to be issued due to cyanobacteria blooms. However, the role of the modified clay in this positive outcome remains unclear, and longevity of the measures questionable.

A new cell primo-culture method for freshwater benthic diatom communities

A new cell primo-culture method was developed for the benthic diatom community isolated from biofilm sampled in rivers. The approach comprised three steps: (1) scraping biofilm from river pebbles, (2) diatom isolation from biofilm, and (3) diatom community culture. With a view to designing a method able to stimulate the growth of diatoms, to limit the development of other microorganisms, and to maintain in culture a community similar to the original natural one, different factors were tested in step 3: cell culture medium (Chu No 10 vs Freshwater “WC” medium modified), cell culture vessel, and time of culture. The results showed that using Chu No 10 medium in an Erlenmeyer flask for cell culture was the optimal method, producing enough biomass for ecotoxicological tests as well as minimising development of other microorganisms. After 96 h of culture, communities differed from the original communities sampled in the two rivers studied. Species tolerant of eutrophic or saprobic conditions were favoured during culture. This method of diatom community culture affords the opportunity to assess, in vitro, the effects of different chemicals or effluents (water samples andindustrial effluents) on diatom communities, as well as on diatom cells, from a wide range of perspectives

Clinical and molecular epidemiological features of coronavirus HKU1-associated community-acquired pneumonia

Background. Recently, we described the discovery of a novel group 2 coronavirus, coronavirus HKU1 (CoV-HKU1), from a patient with pneumonia. However, the clinical and molecular epidemiological features of CoV-HKU1-associated pneumonia are unknown. Methods. Prospectively collected (during a 12-month period) nasopharyngeal aspirates (NPAs) from patients with community-acquired pneumonia from 4 hospitals were subjected to reverse-transcription polymerase chain reaction, for detection of CoV-HKU1. The epidemiological, clinical, and laboratory characteristics of patients with CoV-HKU1-associated pneumonia were analyzed. The pol, spike (S), and nucleocapsid (N) genes were also sequenced. Results. NPAs from 10 (2.4%) of 418 patients with community-acquired pneumonia were found to be positive for CoV-HKU1. All 10 cases occurred in spring and winter. Nine of these patients were adults, and 4 had underlying diseases of the respiratory tract. In the 6 patients from whom serum samples were available, all had a 4-fold change in immunoglobulin (Ig) G titer and/or presence of IgM against CoV-HKU1. The 2 patients who died had significantly lower hemoglobin levels, monocyte counts, albumin levels, and oxygen saturation levels on admission and had more-extensive involvement visible on chest radiographs. Sequence analysis of the pol, S, and N genes revealed 2 genotypes of CoV-HKU1. Conclusions. CoV-HKU1 accounts for 2.4% of community-acquired pneumonia, with 2 genotypes in the study population. Without performance of diagnostic tests, the illness was clinically indistinguishable from other community-acquired pneumonia illnesses. © 2005 by the Infectious Diseases Society of America. All rights reserved.published_or_final_versio

Screening synteny blocks in pairwise genome comparisons through integer programming

<p>Abstract</p> <p>Background</p> <p>It is difficult to accurately interpret chromosomal correspondences such as true orthology and paralogy due to significant divergence of genomes from a common ancestor. Analyses are particularly problematic among lineages that have repeatedly experienced whole genome duplication (WGD) events. To compare multiple "subgenomes" derived from genome duplications, we need to relax the traditional requirements of "one-to-one" syntenic matchings of genomic regions in order to reflect "one-to-many" or more generally "many-to-many" matchings. However this relaxation may result in the identification of synteny blocks that are derived from ancient shared WGDs that are not of interest. For many downstream analyses, we need to eliminate weak, low scoring alignments from pairwise genome comparisons. Our goal is to objectively select subset of synteny blocks whose total scores are maximized while respecting the duplication history of the genomes in comparison. We call this "quota-based" screening of synteny blocks in order to appropriately fill a quota of syntenic relationships within one genome or between two genomes having WGD events.</p> <p>Results</p> <p>We have formulated the synteny block screening as an optimization problem known as "Binary Integer Programming" (BIP), which is solved using existing linear programming solvers. The computer program QUOTA-ALIGN performs this task by creating a clear objective function that maximizes the compatible set of synteny blocks under given constraints on overlaps and depths (corresponding to the duplication history in respective genomes). Such a procedure is useful for any pairwise synteny alignments, but is most useful in lineages affected by multiple WGDs, like plants or fish lineages. For example, there should be a 1:2 ploidy relationship between genome A and B if genome B had an independent WGD subsequent to the divergence of the two genomes. We show through simulations and real examples using plant genomes in the rosid superorder that the quota-based screening can eliminate ambiguous synteny blocks and focus on specific genomic evolutionary events, like the divergence of lineages (in cross-species comparisons) and the most recent WGD (in self comparisons).</p> <p>Conclusions</p> <p>The QUOTA-ALIGN algorithm screens a set of synteny blocks to retain only those compatible with a user specified ploidy relationship between two genomes. These blocks, in turn, may be used for additional downstream analyses such as identifying true orthologous regions in interspecific comparisons. There are two major contributions of QUOTA-ALIGN: 1) reducing the block screening task to a BIP problem, which is novel; 2) providing an efficient software pipeline starting from all-against-all BLAST to the screened synteny blocks with dot plot visualizations. Python codes and full documentations are publicly available <url>http://github.com/tanghaibao/quota-alignment</url>. QUOTA-ALIGN program is also integrated as a major component in SynMap <url>http://genomevolution.com/CoGe/SynMap.pl</url>, offering easier access to thousands of genomes for non-programmers.</p