The use of micro-CT in the investigation of a case involving 3D printed firearms.

This paper highlights how micro-CT was used to assist in the investigation of hybrid firearms constructed using a mixture of plastic and metal components, as a complementary technique to the physical examination performed by firearms experts. In recent years, there has been an increase in the complexity and sophistication of 3D printed and hybrid firearm designs. This was also the case in the investigation presented herein, with the firearms seized demonstrating a step change in the threat level they pose through their complexity.

Spore Germination.

Despite being resistant to a variety of environmental insults, the bacterial endospore can sense the presence of small molecules and respond by germinating, losing the specialized structures of the dormant spore, and resuming active metabolism, before outgrowing into vegetative cells. Our current level of understanding of the spore germination process in bacilli and clostridia is reviewed, with particular emphasis on the germinant receptors characterized in Bacillus subtilis, Bacillus cereus, and Bacillus anthracis. The recent evidence for a local clustering of receptors in a "germinosome" would begin to explain how signals from different receptors could be integrated.

Effect of amino acid substitutions in the GerAA protein on the function of the alanine-responsive germinant receptor of Bacillus subtilis spores.

Spores of Bacillus subtilis require the GerAA, GerAB, and GerAC receptor proteins for L-alanine-induced germination. Mutations in gerAA, both random and site directed, result in phenotypes that identify amino acid residues important for receptor function in broad terms. They highlight the functional importance of two regions in the central, integral membrane domain of GerAA.

Amino acid residues in the GerAB protein important in the function and assembly of the alanine spore germination receptor of Bacillus subtilis 168.

The paradigm gerA operon is required for endospore germination in response to c-alanine as the sole germinant, and the three protein products, GerAA, GerAB, and GerAC are predicted to form a receptor complex in the spore inner membrane. GerAB shows homology to the amino acid-polyamine-organocation (APC) family of single-component transporters and is predicted to be an integral membrane protein with 10 membrane-spanning helices. Site-directed mutations were introduced into the gerAB gene at its natural location on the chromosome.