Global discovery of bacterial RNA-binding proteins by RNase-sensitive gradient profiles reports a new FinO domain protein.

RNA-binding proteins (RBPs) play important roles in bacterial gene expression and physiology but their true number and functional scope remain little understood even in model microbes. To advance global RBP discovery in bacteria, we here establish glycerol gradient sedimentation with RNase treatment and mass spectrometry (GradR). Applied to Salmonella enterica, GradR confirms many known RBPs such as CsrA, Hfq, and ProQ by their RNase-sensitive sedimentation profiles, and discovers the FopA protein as a new member of the emerging family of FinO/ProQ-like RBPs. FopA, encoded on resistance plasmid pCol1B9, primarily targets a small RNA associated with plasmid replication. The target suite of FopA dramatically differs from the related global RBP ProQ, revealing context-dependent selective RNA recognition by FinO-domain RBPs. Numerous other unexpected RNase-induced changes in gradient profiles suggest that cellular RNA helps to organize macromolecular complexes in bacteria. By enabling poly(A)-independent generic RBP discovery, GradR provides an important element in the quest to build a comprehensive catalog of microbial RBPs.

Everything you wanted to know about phase and reference frequency in one- and two-dimensional NMR spectroscopy.

The fundamental concept of phase discussed in this tutorial aimed at providing students with an explanation of the delays and processing parameters they may find in nuclear magnetic resonance (NMR) pulse programs. We consider the phase of radio-frequency pulses, receiver, and magnetization and how all these parameters are related to phases and offsets of signals in spectra. The impact of the off-resonance effect on the phase of the magnetization is discussed before presenting an overview of how adjustment of the time reference of the free induction decay avoids first-order correction of the phase of spectra. The main objective of this tutorial is to show how the relative phase of a pulse and the receiver can be used to change the reference frequency along direct and indirect dimensions of NMR experiments. Unusual of phase incrementation with non-90° angles will be illustrated on one- and two-dimensional NMR spectra.

A Synthetic Tul4 and FopA Peptide Cocktail of Francisella tularensis Induces Humoral and Cell-Mediated Immune Responses in Mice.

Francisella tularensis is a highly virulent pathogen of humans and other mammals. Moreover, F. tularensis has been designated a category A biothreat agent, and there is growing interest in the development of a protective vaccine. In the present study, we determine the in vitro and in vivo immune responses of a subunit vaccine composed of recombinant peptides Tul4 and FopA from epitopes of the F. tularensis outer membrane proteins. The recombinant peptides with adjuvant CpG induced robust immunophenotypic change of dendritic cell (DC) maturation and secretion of inflammatory cytokines (IL-6, IL-12). In addition, the matured DCs enabled ex vivo proliferation of naive splenocytes in a mixed lymphocyte reaction. Lastly, we determined the in vivo immune response by assessment of antibody production in C57BL/ 6 mice. Total IgG levels were produced after immunization and peaked in 6 weeks, and moreover, Tul4-specific IgG was confirmed in the mice receiving peptides with or without CpG. Based on these results, we concluded that the recombinant peptides Tul4 and FopA have immunogenicity and could be a safe subunit vaccine candidate approach against F. tularensis.

Enhanced syndromic surveillance for mass gatherings in the Pacific: a case study of the 11th Festival of Pacific Arts in Solomon Islands, 2012

Mass gatherings pose public health challenges to host countries, as they can cause or exacerbate disease outbreaks within the host location or elsewhere. In July 2012, the 11th Festival of Pacific Arts (FOPA), a mass gathering event involving 22 Pacific island states and territories, was hosted by Solomon Islands. An enhanced syndromic surveillance (ESS) system was implemented for the event. Throughout the capital city, Honiara, 15 sentinel sites were established and successfully took part in the ESS system, which commenced one week before the FOPA (25 June) and concluded eight days after the event (22 July). The ESS involved expanding on the existing syndromic surveillance parameters: from one to 15 sentinel sites, from four to eight syndromes, from aggregated to case-based reporting and from weekly to daily reporting. A web-based system was developed to enable data entry, data storage and data analysis. Towards the end of the ESS period, a focus group discussion and series of key informant interviews were conducted. The ESS was considered a success and played an important role in the early detection of possible outbreaks. For the period of the ESS, 1668 patients with syndrome presentations were received across the 15 sentinel sites. There were no major events of public health significance. Several lessons were learnt that are relevant to ESS in mass gathering scenarios, including the importance of having adequate lead in time for engagement and preparation to ensure appropriate policy and institutional frameworks are put in place.

Generation and amplification of tunable multicolored femtosecond laser pulses by using cascaded four-wave mixing in transparent bulk media.

We have reviewed the generation and amplification of wavelength-tunable multicolored femtosecond laser pulses using cascaded four-wave mixing (CFWM) in transparent bulk media, mainly concentrating on our recent work. Theoretical analysis and calculations based on the phase-matching condition could explain well the process semi-quantitatively. The experimental studies showed: (1) as many as fifteen spectral up-shifted and two spectral down-shifted sidebands were obtained simultaneously with spectral bandwidth broader than 1.8 octaves from near ultraviolet (360 nm) to near infrared (1.2 µm); (2) the obtained sidebands were spatially separated well and had extremely high beam quality with M(2) factor better than 1.1; (3) the wavelengths of the generated multicolor sidebands could be conveniently tuned by changing the crossing angle or simply replacing with different media; (4) as short as 15-fs negatively chirped or nearly transform limited 20-fs multicolored femtosecond pulses were obtained when one of the two input beams was negatively chirped and the other was positively chirped; (5) the pulse energy of the sideband can reach a µJ level with power stability better than 1% RMS; (6) broadband two-dimensional (2-D) multicolored arrays with more than ten periodic columns and more than ten rows were generated in a sapphire plate; (7) the obtained sidebands could be simultaneously spectra broadened and power amplified in another bulk medium by using cross-phase modulation (XPM) in conjunction with four-wave optical parametric amplification (FOPA). The characterization showed that this is interesting and the CFWM sidebands generated by this novel method have good enough qualities in terms of power stability, beam quality, and temporal features suited to various experiments such as ultrafast multicolor time-resolved spectroscopy and multicolor-excitation nonlinear microscopy.