Comment on "A doubly curved elliptical crystal spectrometer for the study of localized x-ray absorption in hot plasmas" [Rev. Sci. Instrum. 85, 103114 (2014)].

The elliptical spectrometer described by Cahill et al. [Rev. Sci. Instrum. 85, 103114 (2014)] is designed to enable absorption X-ray spectroscopy under circumstances in which the object plasma is, itself, a relatively bright X-ray emitter. An implementation of this design was developed using a doubly curved mica crystal for X-ray dispersion. The geometry of the spectrometer was verified by ray tracing calculations assuming Bragg reflection from mica in the second order. Control of X-ray reflections from other orders was an anticipated challenge and has been attempted by means of filtering and control of the source spectrum. These efforts have been found to be insufficient to allow the spectrometer to operate as designed because of the strong fifth order reflection of source radiation by the mica crystal. Potential solutions are presented that may enable a successful implementation of this novel crystal spectrometer design.

A collinear self-emission and laser-backlighting imaging diagnostic.

In this work we demonstrate a design for obtaining laser backlighting (e.g., interferometry) and time-resolved extreme ultraviolet self-emission images along the same line-of-sight. This is achieved by modifying a single optical component in the laser collection optics with apertures and pinhole arrangements suitable for single or multiple frame imaging onto a gated detector, such as a microchannel plate. Test results for exploding wire experiments show that machining of the optic does not affect the overall quality of the recovered laser images, and that, even with a multiple frame system, the area sacrificed to achieve collinear imaging is relatively small. The diagnostics can therefore allow direct correlation of laser and self-emission images and their derived quantities, such as electron density in the case of interferometry. Simple methods of image correlation are also demonstrated.

Polyclonal antibodies to chlorosome proteins as probes for green sulfur bacteria.

We found that polyclonal antibodies raised against chlorosome polypeptides from green sulfur bacteria reacted to Chlorobium tepidum, Chlorobium limicola, and Chlorobium phaeobacteroides but not to Chloroflexus aurantiacus. These antibodies successfully labeled only green sulfur species in marine microbial mat samples. Our results suggest that these antibodies may be useful as immunohistochemical probes.

Development and protective efficacy of a recombinant-DNA derived fimbrial vaccine against enterotoxic colibacillosis in neonatal piglets.

A vaccine containing Escherichia coli fimbriae produced by recombinant-DNA techniques was tested in controlled challenge trials and in commercial piggeries experiencing neonatal enterotoxic colibacillocis. In the challenge trials, piglets suckling vaccinated sows were significantly protected from diarrhoea and colonization of the small intestine by enterotoxigenic E. coli. High titres of anti-fimbrial IgG antibody were detected in the serum and colostrum of vaccinated sows and in serum of their piglets. In the field trials, prevalence of diarrhoea and preweaning mortality due to diarrhoea were greatly reduced in piglets suckling vaccinated sows.