Rare Species Shift the Structure of Bacterial Communities Across Sphagnum Compartments in a Subalpine Peatland

Sphagnum-associated microbiomes are crucial to Sphagnum growth and peatland ecological functions. However, roles of rare species in bacterial communities across Sphagnum compartments are poorly understood. Here the structures of rare taxa (RT) and conditionally abundant and rare taxa (CART) from Sphagnum palustre peat (SP), S. palustre ectosphere (Ecto) and S. palustre endosphere (Endo) were investigated in the Dajiuhu Peatland, central China. Our results showed that plant compartment effects significantly altered the diversities and structures of bacterial communities. The Observed species and Simpson indices of RT and CART in alpha diversity significantly increased from Endo to SP, with those of Ecto in-between. The variations of community dissimilarities of RT and CART among compartments were consistent with those of whole bacterial communities (WBC). Network analysis indicated a non-random co-occurrence pattern of WBC and all keystone species are affiliated with RT and CART, indicating their important role in sustaining the WBC. Furthermore, the community structures of RT and CART in SP were significantly shaped by water table and total nitrogen content, which coincided with the correlations between WBC and environmental factors. Collectively, our results for the first time confirm the importance of rare species to bacterial communities through structural and predicted functional analyses, which expands our understanding of rare species in Sphagnum-associated microbial communities in subalpine peatlands

Cross-protection against European swine influenza viruses in the context of infection immunity against the 2009 pandemic H1N1 virus : studies in the pig model of influenza

Pigs are natural hosts for the same influenza virus subtypes as humans and are a valuable model for cross-protection studies with influenza. In this study, we have used the pig model to examine the extent of virological protection between a) the 2009 pandemic H1N1 (pH1N1) virus and three different European H1 swine influenza virus (SIV) lineages, and b) these H1 viruses and a European H3N2 SIV. Pigs were inoculated intranasally with representative strains of each virus lineage with 6- and 17-week intervals between H1 inoculations and between H1 and H3 inoculations, respectively. Virus titers in nasal swabs and/or tissues of the respiratory tract were determined after each inoculation. There was substantial though differing cross-protection between pH1N1 and other H1 viruses, which was directly correlated with the relatedness in the viral hemagglutinin (HA) and neuraminidase (NA) proteins. Cross-protection against H3N2 was almost complete in pigs with immunity against H1N2, but was weak in H1N1/pH1N1-immune pigs. In conclusion, infection with a live, wild type influenza virus may offer substantial cross-lineage protection against viruses of the same HA and/or NA subtype. True heterosubtypic protection, in contrast, appears to be minimal in natural influenza virus hosts. We discuss our findings in the light of the zoonotic and pandemic risks of SIVs

Sustained antiproliferative mechanisms by RB24, a targeted precursor of multiple inhibitors of epidermal growth factor receptor and a DNA alkylating agent in the A431 epidermal carcinoma of the vulva cell line

Recently, with the purpose of enhancing the potency of epidermal growth factor receptor (EGFR)-based therapies, we designed a novel strategy termed ‘Cascade-release targeting’ that seeks to develop molecules capable of degrading to multiple tyrosine kinase (TK) inhibitors and highly reactive electrophiles, in a stepwise fashion. Here we report on the first prototype of this model, RB24, a masked methyltriazene, that in addition to being an inhibitor on its own was designed to degrade to RB14, ZR08, RB10+a DNA alkylating methyldiazonium species. The cascade degradation of RB24 requires the generation of two reactive electrophiles: (a) an iminium ion and (b) a methyldiazonium ion. Thus, we surmise that these species could alkylate the active site of EGFR, thereby irreversibly blocking its action and that DNA damage could be induced by the methyldiazonium. Using the EGFR-overexpressing human epidermoid carcinoma of the vulva cell line, A431, we demonstrate herein that (a) RB24 and its derived species (e.g. RB14, ZR08) irreversibly inhibit EGFR autophosphorylation, (b) RB24 induced significant levels of DNA strand breaks, (c) sustained inhibition of EGFR by RB24 was associated with blockade of MAPK activation and c-fos gene expression, (d) RB24 induced irreversible cell growth inhibition with a 100-fold greater potency than Temodal™, a clinical methyltriazene. The pronounced growth inhibitory potency of RB24 was attributed to its ability to simultaneously damage DNA and irreversibly block EGFR TK activity

Active dielectric antenna on chip for spatial light modulation

Integrated photonic resonators are widely used to manipulate light propagation in an evanescently-coupled waveguide. While the evanescent coupling scheme works well for planar optical systems that are naturally waveguide based, many optical applications are free-space based, such as imaging, display, holographics, metrology and remote sensing. Here we demonstrate an active dielectric antenna as the interface device that allows the large-scale integration capability of silicon photonics to serve the free-space applications. We show a novel perturbation-base diffractive coupling scheme that allows a high-Q planer resonator to directly interact with and manipulate free-space waves. Using a silicon-based photonic crystal cavity whose resonance can be rapidly tuned with a p-i-n junction, a compact spatial light modulator with an extinction ratio of 9.5 dB and a modulation speed of 150 MHz is demonstrated. Method to improve the modulation speed is discussed.Air Force Office of Scientific Research (AFOSR grant FA9550-12-1-0261

Employment of gene expression profiling to identify transcriptional regulators of hepatic stellate cells

Activated hepatic stellate cells (HSC) play a central role in scar formation that leads to liver fibrosis. The molecular mechanisms underlying this process are not fully understood. Microarray and bioinformatics analyses have proven to be useful in identifying transcription factors that regulate cellular processes such as cell differentiation. Using oligonucleotide microarrays, we performed transcriptional analyses of activated human HSC cultured on Matrigel-coated tissue culture dishes. Examination of microarray data following Matrigel-induced deactivation of HSC revealed a significant down-regulation of myocardin, an important transcriptional regulator in smooth and cardiac muscle development. Thus, gene expression profiling as well as functional assays of activated HSC have provided the first evidence of the involvement of myocardin in HSC activation

Field measurements suggest the mechanism of laser-assisted water condensation

Because of the potential impact on agriculture and other key human activities, efforts have been dedicated to the local control of precipitation. The most common approach consists of dispersing small particles of dry ice, silver iodide, or other salts in the atmosphere. Here we show, using field experiments conducted under various atmospheric conditions, that laser filaments can induce water condensation and fast droplet growth up to several μm in diameter in the atmosphere as soon as the relative humidity exceeds 70%. We propose that this effect relies mainly on photochemical formation of p.p.m.-range concentrations of hygroscopic HNO3, allowing efficient binary HNO3–H2O condensation in the laser filaments. Thermodynamic, as well as kinetic, numerical modelling based on this scenario semiquantitatively reproduces the experimental results, suggesting that particle stabilization by HNO3 has a substantial role in the laser-induced condensation

Sequencing of the Hepatitis C Virus: A Systematic Review

Since the identification of hepatitis C virus (HCV), viral sequencing has been important in understanding HCV classification, epidemiology, evolution, transmission clustering, treatment response and natural history. The length and diversity of the HCV genome has resulted in analysis of certain regions of the virus, however there has been little standardisation of protocols. This systematic review was undertaken to map the location and frequency of sequencing on the HCV genome in peer reviewed publications, with the aim to produce a database of sequencing primers and amplicons to inform future research. Medline and Scopus databases were searched for English language publications based on keyword/MeSH terms related to sequence analysis (9 terms) or HCV (3 terms), plus "primer" as a general search term. Exclusion criteria included non-HCV research, review articles, duplicate records, and incomplete description of HCV sequencing methods. The PCR primer locations of accepted publications were noted, and purpose of sequencing was determined. A total of 450 studies were accepted from the 2099 identified, with 629 HCV sequencing amplicons identified and mapped on the HCV genome. The most commonly sequenced region was the HVR-1 region, often utilised for studies of natural history, clustering/transmission, evolution and treatment response. Studies related to genotyping/classification or epidemiology of HCV genotype generally targeted the 5'UTR, Core and NS5B regions, while treatment response/resistance was assessed mainly in the NS3-NS5B region with emphasis on the Interferon sensitivity determining region (ISDR) region of NS5A. While the sequencing of HCV is generally constricted to certain regions of the HCV genome there is little consistency in the positioning of sequencing primers, with the exception of a few highly referenced manuscripts. This study demonstrates the heterogeneity of HCV sequencing, providing a comprehensive database of previously published primer sets to be utilised in future sequencing studies

Detection and Phylogenetic Analysis of Wolbachia in the Asiatic Rice Leafroller, Cnaphalocrocis medinalis, in Chinese Populations

Wolbachia are a group of intracellular inherited endosymbiontic bacteria infecting a wide range of insects. In this study the infection status of Wolbachia (Rickettsiales: Rickettsiaceae) was measured in the Asiatic rice leafroller, Cnaphalocrocis medinalis (Guenée) (Lepidoptera: Pyralidae), from twenty locations in China by sequencing wsp, ftsZ and 16S rDNA genes. The results showed high infection rates of Wolbachia in C. medinalis populations. Wolbachia was detected in all geographically separate populations; the average infection rate was ∼ 62.5%, and the highest rates were 90% in Wenzhou and Yangzhou populations. The Wolbachia detected in different C. medinalis populations were 100% identical to each other when wsp, ftsZ, and 16S rDNA sequences were compared, with all sequences belonging to the Wolbachia B supergroup. Based on wsp, ftsZ and 16S rDNA sequences of Wolbachia, three phylogenetic trees of similar pattern emerged. This analysis indicated the possibility of inter-species and intra-species horizontal transmission of Wolbachia in different arthropods in related geographical regions. The migration route of C. medinalis in mainland China was also discussed since large differentiation had been found between the wsp sequences of Chinese and Thai populations

Magnetism and its microscopic origin in iron-based high-temperature superconductors

High-temperature superconductivity in the iron-based materials emerges from, or sometimes coexists with, their metallic or insulating parent compound states. This is surprising since these undoped states display dramatically different antiferromagnetic (AF) spin arrangements and N$\rm \acute{e}$el temperatures. Although there is general consensus that magnetic interactions are important for superconductivity, much is still unknown concerning the microscopic origin of the magnetic states. In this review, progress in this area is summarized, focusing on recent experimental and theoretical results and discussing their microscopic implications. It is concluded that the parent compounds are in a state that is more complex than implied by a simple Fermi surface nesting scenario, and a dual description including both itinerant and localized degrees of freedom is needed to properly describe these fascinating materials.Comment: 14 pages, 4 figures, Review article, accepted for publication in Nature Physic

Efficacy, Stability, and Biosafety of Sifuvirtide Gel as a Microbicide Candidate against HIV-1

Sifuvirtide is a proven effective HIV-1 entry inhibitor and its safety profile has been established for systemic administration. The present study evaluated the potential of sifuvirtide formulated in a universal gel for topical use as a microbicide candidate for preventing sexual transmission of HIV. Our data showed that sifuvirtide formulated in HEC gel is effective against HIV-1 B, C subtypes, CRF07_BC and CRF01_AE, the latter two recombinants represents the most prevalent strains in China. In addition, we demonstrated that sifuvirtide in gel is stable for at least 8 weeks even at 40°C, and did not cause the disruption of integrity of mucosal epithelial surface, or the up-regulation of inflammatory cytokines both in vitro or in vivo. These results suggest that sifuvirtide gel is an effective, safe and stable product, and should be further tested as a vaginal or rectal microbicide in pre-clinical model or clinical trial for preventing HIV sexual transmission