No abstract

We investigate simplified models in which dark matter particles, taken to be either Dirac or Majorana fermions, couple to quarks via colored mediators. We determine bounds from colliders and direct detection experiments, and show how the interplay of the two leads to a complementary view of this class of dark matter models. Forecasts for future searches in light of the current constraints are presented.

Protein isoforms with or without a single amino acid residue make a subtle difference. It has been documented on a few genes that alternative splicing generated such isoforms; however, the fact has attracted little attention. We became aware of a subtle sequence difference in DRPLA, a polyglutamine disease gene for dentatorubral pallidoluysian atrophy. Some reported cDNA sequences lacked 3 nucleotides (nt) (CAG), which were positioned apart from the expandable and polymorphic CAG repeats and also coded for glutamine. We experimentally confirmed that the difference was indeed generated by alternative splicing utilizing two acceptors separated by 3 nt. In DRPLA, the expression ratio of two mRNA isoforms was almost constant among tissues, with the CAG-included form being major. The glutamine-included protein isoform was more predominantly localized in the nucleus. Database searching revealed that alternative splice acceptors, as well as donors, are frequently situated very close to each other. We experimentally confirmed two mRNA isoforms of 3 nt difference in more than 200 cases by RT-PCR and found interesting features associated with this phenomena. Inclusion of 3 nt tends to result in single amino acid inclusion despite the phase of translational frame. The expression ratio sometimes varied extensively among tissues.

A rapid procedure was devised for detecting on solid media bacteria able to degrade water-insoluble, solid hydrocarbons such as the polycyclic aromatic hydrocarbons phenanthrene, anthracene, and biphenyl. After Alcaligenesfaecalis AFK2 was inoculated on a plate containing mineral salts agar, an ethereal solution of phenanthrene (about 10%, wt/vol) was sprayed on the surface of the plate, and the plate was incubated at 30°C for 2 to 3 days. Colonies showing degradation were surrounded with clear zones on the opaque plate. A similar clear zone also was formed around colonies which had been grown on a succinate-mineral salts agar or nutrient agar, followed by spraying of the ethereal solution of phenanthrene and further incubating for 1 day. Other phenanthrene-assimilating bacteria, including Beijerinckia Bwt and Pseudomonas SPM64, also formed clear zones on phenanthrene-covered agar plates. This method was applicable to detection of bacteria able to assimilate anthracene, naphthalene, and biphenyl.