Time-Dependent Quotas for the Southern Bluefin Tuna Fishery

It is now officially recognized by the governments of Australia and Japan that the southern bluefin tuna fishery has been overexploited and that harvests must be controlled. A dynamic programming model applicable to multicohort fisheries is developed for finding approximately optimal time-dependent quotas. Results from applying the model to the southern bluefin tuna fishery indicate that restricting or eliminating the Australian catch of under 4-year-olds would benefit both countries.Environmental Economics and Policy, International Relations/Trade, Resource /Energy Economics and Policy,

Characterisation of host growth after infection with a broad-range freshwater cyanopodophage

Freshwater cyanophages are poorly characterised in comparison to their marine counterparts, however, the level of genetic diversity that exists in freshwater cyanophage communities is likely to exceed that found in marine environments, due to the habitat heterogeneity within freshwater systems. Many cyanophages are specialists, infecting a single host species or strain; however, some are less fastidious and infect a number of different host genotypes within the same species or even hosts from different genera. Few instances of host growth characterisation after infection by broad host-range phages have been described. Here we provide an initial characterisation of interactions between a cyanophage isolated from a freshwater fishing lake in the south of England and its hosts. Designated ΦMHI42, the phage is able to infect isolates from two genera of freshwater cyanobacteria, Planktothrix and Microcystis. Transmission Electron Microscopy and Atomic Force Microscopy indicate that ΦMHI42 is a member of the Podoviridae, albeit with a larger than expected capsid. The kinetics of host growth after infection with ΦMHI42 differed across host genera, species and strains in a way that was not related to the growth rate of the uninfected host. To our knowledge, this is the first characterisation of the growth of cyanobacteria in the presence of a broad host-range freshwater cyanophage

Negative effects of makeup use on perceptions of leadership ability across two ethnicities

Cosmetics alter social perceptions, and prior work suggests that cosmetic use may aid female intrasexual competition, making women appear more dominant to other women but more prestigious to other men. It is unclear whether these findings reflect general improvements in perceptions of traits related to women's dominance or if they are specific to mating contexts only. Here, across two ethnicities, we examined effects of cosmetics used for a social night out on perceptions of women's leadership ability, a trait that denotes competence/high status outside of mating contexts. Participants of African and Caucasian ethnicity judged faces for leadership ability where half of the trials differed in ethnicity (own- vs. other-ethnicity face pairs) and the subtlety of the color manipulation (50% vs. 100%). Regardless of the participant's sex or ethnicity, makeup used for a social night out had a negative effect on perceptions of women's leadership ability. Our findings suggest that, in prior work, women are afforded traits related to dominance, as makeup enhances perceptions of traits that are important for successful female mating competition but not other components of social dominance such as leadership

Proto-Brown Dwarf Disks as Products of Protostellar Disk Encounters

The formation of brown dwarfs via encounters between proto-stars has been confirmed with high-resolution numerical simulations with a restricted treatment of the thermal conditions. The new results indicate that young brown dwarfs (BDs) formed this way are disk-like and often reside in multiple systems. The newly-formed proto-BDs disks are up to 18 AU in size and spin rapidly making small-scale bipolar outflows, fragmentation and the possible formation of planetary companions likely as have recently been observed for BDs. The object masses range from 2 to 73 Jupiter masses, distributed in a manner consistent with the observed sub-stellar initial mass function. The simulations usually form multiple BDs on eccentric orbits about a star. One such system was hierarchical, a BD binary in orbit around a star, which may explain recently observed hierarchical systems. One third of the BDs were unbound after a few thousand years and interactions among orbiting BDs may eject more or add to the number of binaries. Improvements over prior work include resolution down to a Jupiter mass, self-consistent models of the vertical structure of the initial disks and careful attention to avoid artificial fragmentation.Comment: 4 pages, 3 figures, accepted for publication in ApJ Letter

From the Chief of Naval Operations

This issue of the Naval War College Review celebrates the centennial of our Naval War College. In a very real sense, it also commemorates the centennial of American naval power and thought, for Captain—later Admiral—Alfred Thayer Mahan was among the first faculty members of this college

Hallucinogenic Drugs

Hallucinogenic drugs have been used for centuries by primitive. man to produce mystic effects usually in religious rites. Perhaps these drugs would not have obta:lned the forefront. they had for while if two Harvard professors, Dr. Timothy Leary and Dr. · Richard Alpert, had not conducted campus experiments with undergraduate students. Working mainly with mescalnie and psilocybin, Leary and Alpert were trying to observe the emotional impact of the drugs and the consciousness broadening power of the drugs. No one, seemed to realize that Alpert and Leary were convinced that the mystic insight one could get from psilocybin would be the solution to the emotional problems of Western man. These experiments have raised the question of the worth of the constructive potentials against the admitted hazards

The effects of season of fire on macroinvertebrates in a longleaf pine-wiregrass community

The effects of season of fire on macroinvertebrate abundance and biomass were studied in a relatively undisturbed longleaf pine-wiregrass (Pinus palustris-Aristida beyrichiana) community at Fort Stewart, Georgia. The objective was to determine how season of fire affected invertebrate abundance and biomass and to relate these effects to wild turkey (Meleagris gallopaw) and northern bobwhite (Colinus virginianus) brood habitat management. Invertebrates were collected using a terrestrial vacuum sampler (D-Vac ®) during the wild turkey and northern bobwhite brood season (April-September) during 1996-97. Treatment plots were burned in May, July, and December of 1996. Total invertebrate abundance (no. invertebrates/transect) and biomass (g invertebrates/transect) were greater in July and unburned plots during the first year. Abundance in May-burned plots attained or surpassed abundance in unburned plots within 2 months after burning. Invertebrate abundance in July-burned plots recovered to that of unburned plots 1 month after burning, while biomass required 2 months to reach levels of unburned plots. May-burned plots had greater overall abundance and biomass than all other treatments 1 year after burning. Plots burned in December of the previous year had the lowest overall abundance and biomass of all treatments 1 year after burning. Overall abundance and biomass of Orthopterans were greater in May-burned plots than all other treatments 1 year after burning. Overall abundance and biomass of Homopterans were greater in plots burned in May and July and unburned plots 1 year after burning. Overall abundance of Coleopterans was greater in July-burned plots and unburned plots 1 year after burning. However, no differences were detected for biomass among treatments. Overall Hymenopteran abundance was greater in May-burned plots than in all other treatments in the year burned and also 1 year after burning. Few relationships were detected between invertebrate abundance and biomass and vegetation composition. Treatment had the greatest impact on invertebrate abundance and biomass. Results indicated that growing-season fire had a short-term negative effect on invertebrate abundance and biomass, but recovered to levels of unburned plots within 2 months after burning. In terms of invertebrates, growing-season fire in longleaf pine-wiregrass stands appears to be compatible with wild turkey and northern bobwhite brood habitat when compared to dormant-season bums or no-burn treatments. The potential negative effects of growing-season fire on nesting and poult and chick production, however, must be considered when applying growing-season fire in wild turkey and northern bobwhite brood habitat