Hematozoa of Common Grackles (Quiscalus quiscula versicolor, Vieillot) in Central Arkansas

During the years 1977-84, 118 bronzed grackles, Quiscalus quiscula versicolor, Vieillot, of 132 examined were found infected with hematozoa. The eight species of symbionts collected from the infected birds included two microfilarial species (Chandlerella quiscali and Eufilaria hibleri), five apicomplexans (Haemoproteus quiscali, Leucocytozoon fringillinarum, Plasmodium matutinum, P. vaughani, P. sp.) and a flagellate (Trypanosoma ontarioensis). P. matutinum and T. ontarioensis represent new host records and all the protozoans represent new locality records. Comparisons are made of symbiont prevalance and diversity as this relates to seasons of the year, sex and age of the host. Comparisons are also made with previous studies on this subspecies

Evaluation of brewers' dried grains in cattle diets

Digitized 2007 AES MoU.Includes bibliographical references (pages 37-39)

Space Station Centrifuge: A Requirement for Life Science Research

A centrifuge with the largest diameter that can be accommodated on Space Station Freedom is required to conduct life science research in the microgravity environment of space. (This was one of the findings of a group of life scientists convened at the University of California, Davis, by Ames Research Center.) The centrifuge will be used as a research tool to understand how gravity affects biological processes; to provide an on-orbit one-g control; and to assess the efficacy of using artificial gravity to counteract the deleterious biological effect of space flight. The rationale for the recommendation and examples of using ground-based centrifugation for animal and plant acceleration studies are presented. Included are four appendixes and an extensive bibliography of hypergravity studies

Enhanced winnings in a mixed-ability population playing a minority game

We study a mixed population of adaptive agents with small and large memories, competing in a minority game. If the agents are sufficiently adaptive, we find that the average winnings per agent can exceed that obtainable in the corresponding pure populations. In contrast to the pure population, the average success rate of the large-memory agents can be greater than 50 percent. The present results are not reproduced if the agents are fed a random history, thereby demonstrating the importance of memory in this system.Comment: 9 pages Latex + 2 figure

Comparison of the Symbiotic Fauna of the Family Plethodontidae in the Ouachita Mountains of Western Arkansas

During the spring of 1985, 101 salamanders representing six host species (29 Plethodon ouachitae, 25 P. caddoensis, 6 P. fourchensis, 23 P. serratus, 13 Desmognathus brimleyorum, and 5 P. glutinosus glutinosus) were collected from six localities in three counties in Arkansas (Polk, Scott, and Montgomery) and examined for symbionts. With the exception of Hannemania dunni, all symbionts recovered from the first five species listed constitute new host records, and the endoparasitic fauna in all species establish new locality records. Examinations revealed one or more species of parasites in 82% of the hosts. Eight species of symbionts (3 nematode, 1 trematode, 1 cestode, 1 protozoan, 1 arthropod, and 1 cystacanth acanthocephalon) were recovered. Conclusions are based on the three host species examined in the largest numbers. Thelandros magnavulvularis and H. dunni were the most commonly occurring parasites, found in five and four host species respectively. Cepedietta michiganensis was restricted to P. ouachitae and Brachycoelium storeriae to P. caddoensis. Hannemania dunni was absent in P. serratus

Multi-Agent Complex Systems and Many-Body Physics

Multi-agent complex systems comprising populations of decision-making particles, have many potential applications across the biological, informational and social sciences. We show that the time-averaged dynamics in such systems bear a striking resemblance to conventional many-body physics. For the specific example of the Minority Game, this analogy enables us to obtain analytic expressions which are in excellent agreement with numerical simulations.Comment: Accepted for publication in Europhysics Letter

A \u3cem\u3eDendroctonus\u3c/em\u3e Bark Engraving (Coleoptera: Scolytidae) From A Middle Eocene \u3cem\u3eLarix\u3c/em\u3e (Coniferales: Pinaceae): Early Or Delayed Colonization?

An engraving made by a scolytid bark beetle, assigned to the genus Dendroctonus of the tribe Tomicini, has been identified on a mummified, middle Eocene (45 Ma) specimen of Larix altoborealis wood from the Canadian High Arctic. Larix altoborealis is the earliest known species of Larix, a distinctive lineage of pinaceous conifers that is taxonomically identifiable by the middle Eocene and achieved a broad continental distribution in northern North America and Eurasia during the late Cenozoic. Dendroctonus currently consists of three highly host-specific lineages that have pinaceous hosts: a basal monospecific clade on Pinoideae (Pinus) and two sister clades that consist of a speciose clade associated exclusively with Pinoideae and six species that breed overwhelmingly in Piceoideae (Picea) and Laricoideae (Pseudotsuga and Larix). The middle Eocene engraving in L. altoborealis represents an early member of Dendroctonus that is ancestral to other congeneric species that colonized a short-bracted species of Larix. This fossil occurrence, buttressed by recent data on the phylogeny of Pinaceae subfamilies and Dendroctonus species, indicates that there was phylogenetically congruent colonization by these bark-beetle lineages of a Pinoideae + (Piceoideae + Laricoideae) host-plant sequence. Based on all available evidence, an hypothesis of a geochronologically early invasion during the Early Cretaceous is supported over an alternative view of late Cenozoic cladogenesis by bark beetles onto the Pinaceae. These data also suggest that host-plant chemistry may be an effective species barrier to colonization by some bark-beetle taxa over geologically long time scales

Incorporating Inertia Into Multi-Agent Systems

We consider a model that demonstrates the crucial role of inertia and stickiness in multi-agent systems, based on the Minority Game (MG). The inertia of an agent is introduced into the game model by allowing agents to apply hypothesis testing when choosing their best strategies, thereby reducing their reactivity towards changes in the environment. We find by extensive numerical simulations that our game shows a remarkable improvement of global cooperation throughout the whole phase space. In other words, the maladaptation behavior due to over-reaction of agents is removed. These agents are also shown to be advantageous over the standard ones, which are sometimes too sensitive to attain a fair success rate. We also calculate analytically the minimum amount of inertia needed to achieve the above improvement. Our calculation is consistent with the numerical simulation results. Finally, we review some related works in the field that show similar behaviors and compare them to our work.Comment: extensively revised, 8 pages, 10 figures in revtex

Dynamical quenching and annealing in self-organization multiagent models

We study the dynamics of a generalized Minority Game (GMG) and of the Bar Attendance Model (BAM) in which a number of agents self-organize to match an attendance that is fixed externally as a control parameter. We compare the usual dynamics used for the Minority Game with one for the BAM that makes a better use of the available information. We study the asymptotic states reached in both frameworks. We show that states that can be assimilated to either thermodynamic equilibrium or quenched configurations can appear in both models, but with different settings. We discuss the relevance of the parameter $G$ that measures the value of the prize for winning in units of the fine for losing. We also provide an annealing protocol by which the quenched configurations of the GMG can progressively be modified to reach an asymptotic equlibrium state that coincides with the one obtained with the BAM.Comment: around 20 pages, 10 figure