A unique Mycobacterium species isolated from an epizootic of striped bass (Morone saxatilis)

We isolated a Mycobacterium sp. resembling Mycobacterium marinum and M. ulcerans from diseased striped bass (Morone saxatilis) during an epizootic of mycobacteriosis in the Chesapeake Bay. This isolate may represent an undescribed Mycobacterium species, based on phenotypic characteristics and comparative 16S rRNA gene sequence

Comparison of plasmids isolated from romet-30-resistant edwardsiella ictaluri and tribrissen-resistant escherichia coli

Edwardsiella ictaluri, the etiological agent of enteric septicemia of channel catfish (ESC), is the leading cause of bacterial disease in commercially raised channel catfish Ictalurus punctatus. The only drug approved by U.S. Food and Drug Administration for use against ESC is Romet-30. Recently, several isolates were obtained that had a naturally occurring resistance to Romet-30. On further characterization these isolates were shown to possess a 55-kilobase (kb) plasmid that encodes resistance to the drug. We compared Romet-30-resistant E. ictaluri and a Tribrissen-resistant strain of Escherichia coli (strain 1898) isolated from equine cystitis. Antimicrobial profiles, plasmid screening, restriction digest, and Southern blot analysis indicated that the two plasmids are very similar. The resistance afforded to the E. coli was encoded by a 55-kb plasmid. Each of the R plasmids conferred resistance to Romet-30, tetracycline, and Terramycin (oxytetracycline). The R plasmid from E. coli strain 1898 was transferred to Romet-30-sensitive isolates of E. ictaluri by single-step conjugation, rendering the transconjugates resistant to Romet-30, tetracycline, and Terramycin. Each plasmid was cleaved into fragments by restriction enzymes, then electrophoresed in an agarose gel and transferred to nitrocellulose. A labeled probe prepared from the R plasmid of E. ictaluri isolate 5-90-156, one of the original Romet-30-resistant E. ictaluri isolates, was added. Restriction enzyme digestion resulted in an equal number of fragments of equal mobility for the two plasmids, and the probe hybridized with the same fragments of each plasmid. These results indicate that the R plasmids of E. ictaluri and E. coli are similar, if not identical. © by the American Fisheries Society 1993

Public choice principles of redistricting

This paper uses fundamental principles of public choice, mainly the median voter theorem, to develop a simple theory of redistricting. The focus is on how closely policy outcomes correspond to majority rule. The main results are: (1) Potential policy bias in favor of nonmajority groups is structurally linked to the number of legislative seats and the population, and the structure of most states puts them very close to the theoretically maximum bias. (2) Random districting, which might seem like the essence of neutrality, does not eliminate policy bias on average. (3) Traditional principles of compact, contiguous districts that respect existing political boundaries, stressed in the Supreme Court’s Shaw v. Reno decision, minimize the chance of nonmajoritarian outcomes. Our analysis also offers a gerrymandering explanation for the positive relation between seats and spending that is usually taken as support for the “Law of 1/n.” Copyright Springer Science + Business Media B.V. 2006Redistricting, Voting rights, Median voter,

Discretionary Authority and Prioritizing in Government Agencies

Government agencies typically have a certain freedom to choose among different possible courses of action. This paper studies agency decision-making on priorities in a principal-agent framework with multi-tasking. The agency head (the principal) has discretion over part of the agency's budget to incentivize his staff (agents) in the pick-up of cases. The head is concerned with society's benefits from the agency's overall performance, but also with the organization's public image as formed from pursuing high-profile cases and various non-case specific activities. Based on their talent and the contracts offered by the head, staff officials choose which type of task to pursue: complex major, yet difficult to complete cases with an uncertain outcome, or basic minor and simple cases with a high probability of success. The size of the agency's discretionary budget influences not only the scale, but also the type of tasks it will engage in. Social welfare is non-monotonic and discontinuous in the agency's budget. Small changes in the budget may cause extensive restructuring from major to minor tasks, or vice versa. A budget cut can increase welfare more than too little extra budget would. For lower binding budgets, the head continues to sub-optimally incentivize work on complex tasks, when the agency should have shifted down to simpler tasks. In determining the discretionary space of the agency head, the budget-setter can limit the extraction of resources, but thereby also reduces the benefits from the head's superior information on how to incentivize the officials. Antitrust authorities serve as one illustration of policy implications for institutional design, including optimal budgeting and agency mergers