Dominance and experience: Aggression and the evolutionary origins of social behavior

Sociality as a life history strategy has many overt benefits, but its origin from solitary living is not fully understood. The cooperation necessary for formation of even basic social groups can present natural selection paradoxes that many models are unable to reconcile. Conversely, aggression is a key component to the formation of dominance hierarchies, a very basic form of social group. These hierarchies can give way to reproductive hierarchies, which are in turn the basis for some of the most complex forms of social organization. The focus of this thesis is to use aggression in an incipiently social bee species to characterize behavioral and genetic patterns useful for further study of the mechanisms behind the evolution of sociality. In agonistic encounters and contests between conspecifics, the outcome can be determined by physiological traits like size, age, or reproductive activity, by prior experience, or by a combination of these factors. Past experience can inform future efforts, resulting in repetition of the same outcome, while physiological traits can create hierarchies of size, age, etc. Repeated pairings of small carpenter bees (Ceratina calcarata) by circle tube forced association revealed cumulative roles for both size and experience in determining contest outcomes. Size predicted initial dominance, while experience determined subsequent outcomes. I posit that these results may hold true for other species at simple stages of social complexity, and may be important for behavioral studies of social evolution. The brain gene expression corresponding with these behavioral results similarly yielded targets for evolutionary study. Behavioral syndromes resulting from repeated interactions in the first experiment resulted in significant upregulation of genes of memory, learning, axonogenesis, and transcription regulation in dominant individuals. These genes and their behavioral contexts matched those of a variety of taxa, as did a number of gene ontology terms with similar functions. Enrichment of several transcription factor binding motifs also revealed potential behavioral functions for cis-regulatory elements that are conserved across taxa. Overall, the results suggest key roles for genes, ontology terms, and cis-regulatory elements in behavioral response to aggression, in both simple and complex social groups. I propose that these be used as the foci for future experiments in order to determine the relative role of each of these target factors. Combining behavioral and genetic data with comparisons to a wide range of taxa gives a more detailed look at the factors that may have influenced the evolution of sociality. These behavioral patterns and target genes/regulatory elements may provide valuable insights to further understanding the origins of animal societies

Land Grant Application- Withee, Zoe (Zoa) (Industry)

Land grant application submitted to the Maine Land Office for Zoe (Zoa) Withee for service in the Revolutionary War.https://digitalmaine.com/revolutionary_war_me_land_office/1998/thumbnail.jp

Fully coupled dynamic analysis of a floating wind turbine system

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 2004.Includes bibliographical references (leaves 150-151).The use of wind power is in a period of rapid growth worldwide and wind energy systems have emerged as a promising technology for utilizing offshore wind resources for the large scale generation of electricity. Drawing upon the maturity of wind turbine and floater technologies developed by the wind energy and oil and gas industries, respectively, large offshore wind energy systems have been developed and are being proposed for operation in offshore areas where environmental restrictions are less restrictive, large wind resources exist, and open sea areas are available for wind farm development. A fully coupled dynamic analysis technique was developed to predict the response of a floating wind turbine system in a stochastic wind and wave environment. This technique incorporated both non- linear wave loading on the submerged floater and the aerodynamic loading on the wind turbine. A tension leg spar buoy was designed to support the wind turbine. This design was chosen due to its relatively small size and hence lower potential cost per wind turbine. The system's tethers were attached to the ends of spokes which radiated out from the spar cylinder. This arrangement of lines and spokes promised to be very stiff in the roll and pitch modes of motion.(cont.) The fully coupled analysis technique was used to evaluate the feasibility of the chosen floater design. Damping properties of the combined floater / wind turbine system were determined by conducting simulated free decay tests for the different modes of motion and wind turbine operating conditions. Numerical simulations for operational conditions were also carried out. The response of the floating wind turbine to three different sets of environmental conditions was determined and compared to a fixed base system. Additional simulations were conducted to determine extreme wind and wave event response. Stiffness of the floating system in roll and pitch was found to be a desirable attribute. The results of the analysis demonstrated that the tension leg spar buoy has the potential to support a wind turbine in an offshore environment without adversely affecting the loading on the system components.by Jon E. Withee.Ph.D

Design and Test of Mixed-flow Impellers II : Experimental Results, Impeller Model MFI-1A

An investigation was conducted to determine the performance characteristics of a mixed-flow impeller which was designed with special emphasis on the reduction or elimination of flow decelerations along wetted surfaces. The performance was investigated over a range of equivalent impeller speeds from 700 to 1600 feet per second and over a range of flow rates from maximum adiabatic temperature-rise efficiency, measured at 1-1/2 impeller diameters in a vaneless diffuser, at the design speed of 1400 feet per second were 4.00 and 0.83, respectively

Design and Test of Mixed-flow Impellers IV : Experimental Results for Impeller Models MFI-1 and MFI-2 with Changes in Blade Height

Modifications A and B of impeller model MFI-1 and A, B, and C of impeller model MFI-2 were investigated experimentally in an attempt to determine what allowance in blade height should be made for boundary layer and viscous losses in an impeller designed for isentropic compressible flow. A gradual increase in blade height was arbitrarily made from inlet to outlet in anticipation of a gradual build-up of boundary layer. Apparently there was a rapid build-up of boundary layer near the inlet in the experimental case rather than a gradual one. Therefore, the proper allowance for boundary layer cannot be described from the data obtained. Decreasing the pressure gradient along the shroud by reducing the blade height allowance apparently did little to increase the overall efficiency. At the design speed of 1400 feet per second, the overall adiabatic efficiency was increased from 0.83 for the MFI-1A to 0.85 for the MFI-1B with reduction in height; however, it is indicated from the theoretical velocity distribution and outlet surveys that the increase was due to a change from decelerating to accelerating flow along the hub rather than from any change along the shroud. It is further indicated that the consequences of a thickened or separated boundary layer depend not only on the design velocity gradients but also on the shape of the passage