An improvement of discrete Tardos fingerprinting codes

It has been proven that the code lengths of Tardos’s collusion-secure fingerprinting codes are of theoretically minimal order with respect to the number of adversarial users (pirates). However, the code lengths can be further reduced as some preceding studies have revealed. In this article we improve a recent discrete variant of Tardos’s codes, and give a security proof of our codes under an assumption weaker than the original Marking Assumption. Our analysis shows that our codes have significantly shorter lengths than Tardos’s codes. For example, when c = 8, our code length is about 4.94% of Tardos’s code in a practical setting and about 4.62% in a certain limit case. Our code lengths for large c are asymptotically about 5.35% of Tardos’s codes. A part of this work was presented at 17th Applied Algebra, Algebraic Algorithms, and Error Correcting Codes (AAECC-17), Bangalore, India, December 16–20, 2007.     

Comparative study of complete and incomplete Freund's adjuvants for immunization of a drug immunogen using enzyme immunoassay methods

Highly sensitive and accurate enzyme immunoassays (EIAs), a sandwich EIA for mouse immunoglobulin G (IgG) and an enzyme linked immunosorbent assay for mouse antibody specific to viomycin (VM), were developed. Accuracy and specificity of the assay results were confirmed before their application. The changes of total IgG and antibody specific to VM in mice, immunized with a VM-immunogen with or without two types of Freund's adjuvants under various conditions, were assessed by means of the newly developed EIA methods. Both methods were very useful tools to follow the immunization processes of mice, and complete and incomplete Freund's adjuvant were found to have similar adjuvant activities for production of antibody specific to VM, judging from the amounts of anti-VM antibody formed. It seems to be important that too many booster injections should be avoided in the immunization of mice with a hapten immunogen.     

Electromagnetic moments of the doubly closed shell ±1 nucleon nuclei and on-line nuclear polarization

Electromagnetic moments of doubly closed shell ±1 nucleon nuclei were studied. Recent technical developments of the β-NMR was shown that was applicable for the polarized β emitters. Also, the implication of those new moments were discussed especially on the nuclear interactions and non nucleonic degrees of freedom.     

Studies on the optimal immunization schedule of experimental animals. VI. Antigen dose-response of aluminum hydroxide-aided immunization and booster effect under low antigen dose

The dose-response relationships of a viomycin (VM) immunogen for total immunoglobulin (Ig) G and anti-VM antibody response of mouse using aluminum hydroxide as adjuvant was studied. The condition required to absorb a protein on aluminum gel was first established. The effective immunogen dose for total and specific IgG response of mouse using aluminum hydroxide as the adjuvant was found to be in the narrow range of 5 to 20 micrograms, and 10 micrograms per mouse was optimal. The most effective number and intervals of booster injections were studied; when mice were immunized with a lower antigen dose than the optimal, both the number and interval period of booster injections greatly affected the immune response; the more boosters were given, the higher was the response level of specific IgG. The results are contrary to those obtained by immunizing with the optimal or a higher antigen dose.     

Theoretical studies on magnetic interactions between Cu(II) ions in hydroxypyridone nucleobases

The origin of a ferromagnetic interaction between Cu²⁺ ions in the Cu²⁺–DNA system which reported by Tanaka et al. is examined by using DFT calculations. In order to consider effects of an entanglement and a dis-entanglement of the double helix chain, three types of structural disorders i.e. distance, rotation angle and discrepancy in XY-plane, are considered in the model dimer structure. All calculated results show that J_ab values are weak anti-ferromagnetic couplings. Boltzmann distribution simulation indicates that the high spin (HS) species exist 21% at 1.5 K by thermal excitation within the model structure.