Detectors for the Gamma-Ray Resonant Absorption (GRA) Method of Explosives Detection in Cargo: A Comparative Study

Gamma-Ray Resonant Absorption (GRA) is an automatic-decision radiographic screening technique that combines high radiation penetration with very good sensitivity and specificity to nitrogenous explosives. The method is particularly well-suited to inspection of large, massive objects (since the incident gamma-ray probe is at 9.17 MeV) such as aviation and marine containers, heavy vehicles and railroad cars. Two kinds of gamma-ray detectors have been employed to date in GRA systems: 1) Resonant-response nitrogen-rich liquid scintillators and 2) BGO detectors. This paper analyses and compares the response of these detector-types to the resonant radiation, in terms of single-pixel figures of merit. The latter are sensitive not only to detector response, but also to accelerator-beam quality, via the properties of the nuclear reaction that produces the resonant gamma-rays. Generally, resonant detectors give rise to much higher nitrogen-contrast sensitivity in the radiographic image than their non-resonant detector counterparts and furthermore, do not require proton beams of high energy-resolution. By comparison, the non-resonant detectors have higher gamma-detection efficiency, but their contrast sensitivity is very sensitive to the quality of the accelerator beam. Implications of these detector/accelerator characteristics for eventual GRA field systems are discussed.Comment: 11 page

Different transcriptional response between susceptible and resistant common carp (Cyprinus carpio) fish hints on the mechanism of CyHV-3 disease resistance

Infectious disease outbreaks form major setbacks to aquaculture production and to further development of this important sector. Cyprinid herpes virus-3 (CyHV-3) is a dsDNA virus widely hampering production of common carp (Cyprinus carpio), one of the most farmed fish species worldwide. Genetically disease resistant strains are highly sought after as a sustainable solution to this problem. To study the genetic basis and cellular pathways underlying disease resistance, RNA-Seq was used to characterize transcriptional responses of susceptible and resistant fish at day 4 after CyHV-3 infection

The Costs of Sovereignty

Since the late 19th century, when the first Zionist settlers arrived in the area called Palestine, the relationship between the local Jews and the Arabs has been perceived as a zerosum game. A zero-sum game is one which generates solutions that favor one side or the other, but not both; the gain of one is the loss of the other. These games often produce equilibrium solutions, some of which are durable and stable. However, when they assume the form ascribed by Nash, or when the preferences of ..

Gene expression in response to antagonist treatment.

<p>Gene expression in OVCAR3, WISH and T47D cells in response to antagonists, YNS and IFNα2. (A) Cells were treated for 8 hours with 200 nM antagonists or 1nM YNS, and analyzed by qPCR. The data presented are the relative expression levels compared to those of untreated cells, normalized against HPRT1. (B) As described in (A), but cells were treated for 24 hours. (C) Cells were treated with a combination of 200 nM antagonist and 200 pM IFMα2. Gene induction was analyzed as described in (A). Error bars represent standard deviation of the data.</p

Binding of IFNα2 and its mutants to the IFNAR1 and IFNAR2 receptor subunits.

<p>(A) Ribbon representation (based on Protein Data Bank #3SE3) [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0130797#pone.0130797.ref029" target="_blank">29</a>] of the ternary complex of IFNAR1 (R1), IFNAR2 (R2) and IFN, including the locations of the point mutations of the antagonists. On the right is a representation of the antagonist, which binds tighter to R2, but does not bind R1. (B) SPR sensograms of different IFNs (analyte) binding IFNAR2 (surface bound ligand) measured on a ProteOnXPR36. (C) IFNAR1-binding equilibrium analysis of the antagonists and IFNα2. The measurements were done using the ProteOn XPR36 Protein Interaction Array System (BioRad) with IFNAR1 and IFNAR2 immobilized on the sensor chip. For equilibrium binding analysis towards IFNAR1, six different concentrations of the interferon proteins were administrated, and the data were fitted using the mass action equation. (D) <i>In situ</i> measurements of the interferon antagonists towards the IFNAR receptor subunits. The 50% competition values for the four antagonists are ~1 nM, in line with their binding affinities to IFNAR2. 1000-fold lower than the EC₅₀ value determined for YNS. All extracted data from panels C-E are presented in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0130797#pone.0130797.t001" target="_blank">Table 1</a>.</p