Truck escape ramp design methodology. Volume 2. Final report.

Federal Highway Administration, Washington, D.C.

An overview of roadway delineation research. Phase III. Final report.

Federal Highway Administration, Washington, D.C.

Performance of two ice-retardant overlays. Final report.

Federal Highway Administration, Office of Research, Development and Technology, Washington, D.C.

Retroreflective requirements for traffic signs - a STOP case study. Final report.

Mode of access: Internet.

Response of asphalt concrete pavements to dynamic truck loads. Final report.

California Department of Transportation, Sacramento

Field evaluation of miles-per-gallon meters. Final report.

Transportation Systems Center, Cambridge, Mass.

Impact characteristics of glass fiber-reinforced composite materials for use in roadside safety barriers. Final report.

Federal Highway Administration, McLean Va.

Development of vehicle rollover maneuver. Volume I. Final report.

National Highway Traffic Safety Administration, Washington, D.C.

Development of vehicle rollover maneuver. Volume II. Executive summary report.

National Highway Traffic Safety Administration, Washington, D.C.

Sand ripple growth in an oscillatory-flow water tunnel /

The development of sand ripples in an oscillatory-flow water tunnel was observed in 104 laboratory experiments approximating conditions at the seabed under steady progressive surface waves. The period, T, and amplitude, a, of the water motion were varied over wide ranges. Three quartz sands were used, with mean grain diameters, D = 0.55, 0.21, and 0.18 millimeter. In 24 experiments, with the bed initially leveled, T was reduced until ripples appeared, and their development to final equilibrium form was observed without further change in T. The remaining 80 experiments investigated the response of previously established bed forms to changes in T or a or both. The ripple length, lambda, and height, eta, were measured from photos, except when bed forms were three dimensional.

Mollusca Non-Grata: The influence of top-down control and residence time on the abundance, distribution, and behavior of non-native marine snails in Washington State

Thesis (Ph.D.)--University of Washington, 2016-06

Sea anemone host selection by the symbiotic saddled cleaner shrimp Periclimenes holthuisi

A preliminary field survey was conducted to determine the distribution of ectosymbiotic shrimp Periclimenes holthuisi on the sea anemone Stichodactyla haddoni in Moreton Bay (Queensland, Australia). Laboratory experiments were also carried out to verify whether the shrimp show a preference for one anemone host. In the field, 45 individuals of P. holthuisi were found to be associated with 70% of the specimens of S. haddoni (n=20). We inferred this shrimp population was not space-limited because not all anemones were colonized. After having been isolated from their natural host for 2 weeks, when placed between individuals of S. haddoni and Macrodactyla doreensis (an anemone that is sympatric with S. haddoni), shrimp overwhelmingly selected S. haddoni (92%). To establish whether M. doreensis may serve as an alternative host for P. holthuisi, unacclimated shrimp were forced to associate with this anemone. Macrodactyla doreensis showed little tentacle reaction during this association; shrimp were found on the anemone's tentacles and the column. The finding that M. doreensis can serve as an alternative host for P. holthuisi demonstrates that this anemoneshrimp is adaptable to another anemone host and thus may not be highly host specific.

Divergent environments and population bottlenecks fail to generate premating isolation in Drosophila pseudoobscura

While the feasibility of bottleneck-induced speciation is in doubt, population bottlenecks may still affect the speciation process by interacting with divergent selection. To explore this possibility, I conducted a laboratory speciation experiment using Drosophila pseudoobscura involving 78 replicate populations assigned in a two-way factorial design to both bottleneck (present vs. absent) and environment (ancestral vs. novel) treatments. Populations independently evolved under these treatments and were then tested for assortative mating and male mating success against their common ancestor. Bottlenecks alone did not generate any premating isolation, despite an experimental design that was conducive to bottleneck-induced speciation. Premating isolation also did not evolve in the novel environment treatment, neither in the presence nor absence of bottlenecks. However, male mating success was significantly reduced in the novel environment treatment, both as a plastic response to this environment and as a result of environment-dependent inbreeding effects in the bottlenecked populations. Reduced mating success of derived males will hamper speciation by enhancing the mating success of immigrant, ancestral males. Novel environments are generally thought to promote ecological speciation by generating divergent natural selection. In the current experiment, however, the novel environment did not cause the evolution of any premating isolation and it reduced the likelihood of speciation through its effects on male mating success.

Undular tidal bore dynamics in the Daly Estuary, Northern Australia

Measurements in the macro-tidal Daly Estuary show that the presence of an undular tidal bore contributed negligibly to the dissipation of tidal energy. No recirculation bubble was observed between a trough and the following wave crest in the lee waves following the undular bore. This differs to stationary undular bores in laboratory experiments at larger Froude numbers where a recirculation bubble exists. Secondary motions and the turbulence generated by the undular bore had no measurable influence on the sediment transport. This situation contrasts with the intense sediment resuspension observed in breaking tidal bores. The tidally averaged sediment budget in the Daly Estuary was controlled by the asymmetry of tidal currents. The undular bore may widen the river by breaking along the banks that it undercuts, leading to bank slippage. A patch of river-wide macro-turbulence of 3-min duration occurred about 20 min after the passage of the bore during accelerating tidal currents. (C) 2004 Elsevier Ltd. All rights reserved.

Parasitic isopod Anilocra apogonae, a drag for the cardinal fish Cheilodipterus quinquelineatus

Cymothoid isopods Anilocra apogonae are regular ectoparasites of the cardinal fish Cheilodipterus quinquelineatus on the Great Barrier Reef. To determine whether this large isopod, attached to the head of the fish, affects the physiology and behaviour of its host, we conducted morphological measurements to obtain a condition index and several laboratory experiments on fish with and without isopods. The condition index did not vary between parasitised and non-parasitised wild fish. However, we found that parasitised fish lost more weight than unparasitised fish when fed a low food ration. Parasitised fish also had a higher rate of oxygen consumption than non-parasitised fish. When maintaining body posture in calm water, parasitised fish had an elevated pectoral fin beat frequency, probably because the isopod attaches asymmetrically, causing an asymmetrical weight balance for which the fish needs to compensate. Moreover, the sustained aerobic swimming speed as well as the swimming endurance at high water speeds were reduced in parasitised fish, possibly because of the drag from the parasite. The results suggest that parasites can have significant effects on fish even if this is not revealed by their body condition index in the wild. The metabolic effects found imply that parasitised fish may have to spend more time foraging to compensate for their higher metabolism. This could expose them to a higher risk of being eaten, a situation made worse by an impaired swimming ability that may reduce their capacity to escape a predator.