The aim of this work was to investigate techniques for controlling the movement of free-ranging rainbow trout. In the first part of the study groups of 50 rainbow trout were successfully conditioned to aggregate at a loudspeaker and feeding point in a 3.5m x 3.5m x 3.5m enclosure in response to a pulsed 140-Hz sound signal played for 10s prior to and during feeding. The development of the response was quantified using three techniques and a study of the factors involved in conditioning showed that, (1) the number of trials was the important criteria in establishing the conditioned response, (2) other fish and the visual cues associated with the experimental environment, as well as the sound signal, were used to mediate the conditioned response and (3) an increase in the size of the conditioning enclosure adversely affected the rate of conditioning. Additional experiments showed that the sound signal amplitude was positively correlated with the number and activity of fish attracted to feed and that conditioned fish "generalized" to frequencies of between 50 and 380Hz. Anaesthesia and handling, and 24 days without training, did not adversely 'affect the conditioned response. In the second part of the study naive fish and fish pre-conditioned to a sound signal were released into an 8-acre loch in two separate experiments. These experiments examined the movements of rainbow trout in relation to an artificial feeding station and showed that fish were attracted to and remained close to the feeding station even in the absence of a sound signal. Preconditioned fish were not attracted to feed using sound although the experimental conditions prevailing at the time of this experiment could have adversely affected the results. A food delivery was, however, a very successful altractant and the possibility of feeding sounds being used in this attraction was investigated, but rejected. The role of other possible cues are discussed. Further experiments quantified the dial changes in the number of fish and the size of the area covered by the group of fish at the feeding station and showed that ration size controlled the numbers aggregating there. The diet and return of stocked rainbow trout were analysed and compared with previous studies. An additional study carried out in an 185acre loch showed that a rainbow trout cage farm had a significant effect on the distribution of rainbow trout within the loch because the cages acted (unintentionally) as supplementary feeding points. Their behaviour is discussed in relation to the results from the previous experiments. Some observations on the swimming behaviour of rainbow ttout in sea cages are also discussed.

Since its invention, phased array has been extensively applied in both military and civil areas. The applications include target detecting and tracking, space probe communication, broadcasting, human-machine interfaces, and remote sensing. Although the phased array applications show a broad range of potential market, there are some limitations of phased array's development: high cost, complex structure, narrow bandwidth, and high power consumption. Therefore, novel ideas are needed to reduce these constraints. In this thesis, several new approaches about the design and application of phased array are presents. First, the principle of phased array and fundamental design equations are introduced. Second, a new application of phased array antenna for radar respiration measurement is presented. By integrating a 4×4 Butler matrix with four-element antenna array, there will be four distinct main beams in radiation pattern. This new approach can improve the measurement accuracy and realize a high detecting rate. Third, a compact phased array antenna system based on dual-band operations is introduced. Dual-band function can make N-antenna system obtain 2N unique radiation beams (N is an integer) and achieve a significant size reduction compared to the conventional single-band system. To verify the design concept, a four-element phased array antenna working at 5GHz and 8GHz is designed and fabricated. The measurement results make a good agreement with the simulations. Finally, a novel architecture of steering phase feeding network by using bi-directional series-fed topology is presented. This bi-directional series-fed network needs less phase shifters and realizes steering phase function by applying control voltage.

Master of Science / Department of Entomology / Jeremy L. Marshall / Males providing females with gifts in order to mate is not a novel occurrence. Indeed, depending on the taxonomic system, males may provide gifts ranging from dead insects, to nutritious ejaculates to even subjecting themselves to cannibalistic feeding. Interestingly, while the burden of the costs of these gifts is primarily carried by the male, net fitness of providing or receiving such gifts must be positive for both sexes, if these gifts are to be maintained in a population. If this is not the case, and sexual conflict has exerted a cost-benefit imbalance between the sexes, then the expectation is that the system will evolve towards the reduction of nuptial gift giving. Here, utilizing the Allonemobius socius complex of crickets where females benefit greatly from cannibalizing male blood as a nuptial gift, we explore the possibility that sexual conflict is acting on gift size. To do this, we assess the gift-size distribution, and their associated fitness functions, for twelve populations that span the phylogeny and geographic distribution of this complex. We find that gift-size distributions are shifted towards small or no gifts in the majority of populations. Moreover, fitness data suggest that males providing a small or even no gift are equally successful to their large gift-giving counterparts. Taken together, the population profiles indicate that at least half of these populations are evolving towards the near or complete loss of these cannibalistic gifts – a predicted, but previously undocumented, outcome of sexual conflict. We also assess the speed at which sexual conflict is acting to alter gift size distributions in populations by comparing gift sizes between different time points in populations and across phylogenetic history. The implications of these results are discussed relative to antagonistic coevolution of behavioral traits and sexual conflict theory in general.

No description available.

LD2668 .T4 1949 V6 / Master of Science

Call number: LD2668 .T4 1957 V82 / Master of Science

Call number: LD2668 .T4 1959 R66

Call number: LD2668 .T4 1986 R52 / Master of Science / Animal Sciences and Industry

LD2668 .T4 1950 A37 / Master of Science

Call number: LD2668 .T4 1957 P63 / Master of Science