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A central question in life history theory is, what combination of traits and behaviors will lead to the highest reproductive success throughout a lifetime. The trade-off between current and future reproduction is central to the lifetime reproductive success of an organism. If there is a cost to reproduction, then allocation of energy to current reproduction will come at a cost to future reproduction. We expect young individuals to favor future reproduction over current reproduction and that balance shifts to current reproduction as they age (i.e. terminal investment hypothesis). However, how this transition from an emphasis on future reproduction to emphasis on current reproduction changes throughout a lifetime should depend on environmental factors like mortality and resource availability. We test for the generality of terminal investment across three species of poecilliid fishes in a range of environments. We found evidence of terminal investment in all three species in both high and low mortality environments and high and low resource availability environments. In general, high mortality or high resource availability tended to result in a decreased slope of the relationship between reproductive allocation and body size. Terminal investment appears to be general, even though there was an effect of high mortality and resource availability, it was not sufficient to completely preclude terminal investment.

The cost of reproduction hypothesis suggests that allocation into current reproduction constrains future reproduction. How organisms accrue reproductive costs may differ between species and with varying levels of resource quality. Burying beetles are model organisms for testing for the cost of reproduction because of their unique natural history; beetles utilize small vertebrate carcasses for reproduction and they and their offspring feed exclusively on these discrete resources. Burying beetles also can utilize a large range of carcass sizes for reproduction. We tested for the cost of reproduction in two species of burying beetles, Nicrophorus marginatus and Nicrophorus guttula found in Central Utah by breeding beetles on a range of carcass sizes (5g, 10g, 20g, 30g, 40g, and 50g carcasses). We also used a manipulation experiment to force beetles into over-allocating energy into reproduction to assess reproductive costs. For both species, reproduction was costly, with beetles suffering reduced lifespan and reduced lifetime fecundity with increased resource quality. Both species also showed clear signs of senescence, having reduced brood size and lower efficiency as individuals aged. Females did not show indications of terminal investment in terms of female mass change, unlike the previously studied Nicrophorus orbicollis, which gained less mass after each reproductive attempt as it aged. Nicrophorus marginatus consistently outperformed N. guttula in terms of total number of offspring produced for all carcass sizes. Nicrophorus guttula populations may continue to persist with N. marginatus by exploiting a less desirable but more abundant resource.

The militaristic interpretations of the art of Chichen Itza, Yucatán, Mexico, fails to sufficiently describe its entire decorative program. Absent from discussions of the art tradition is the apparent focus on merchant activity in the city. The influence and power of merchants strengthened during the transition from the Classic to Postclassic in Mesoamerica. With an increase in demand of foreign goods, new exchange relationships developed between centers in Central Mexico, the Gulf, and Maya region. As a result, several cultural regions participated in a vast economic network that created political alliances and syncretic art styles. Focusing on the mural tradition of Chichen Itza, this study proposes a chronological sequence for the wall paintings by examining their style, subject matter, and architectural setting. Analysis of the painted images demonstrates the progressive development of merchant activity in the city and its influence in establishing Chichen Itza as one of the major centers of long-distance trade by the Terminal Classic.

Recent excavations uncovered numerous small rooms constructed on top of the Danta Acropolis at El Mirador, Guatemala. The characteristics of the settlement and the material items indicated that it was a late occupation and lacked the features associated with large Maya polities and Classic Maya culture. This thesis focused on describing the continuities and changes that occurred from the Late Classic to the Terminal Classic at El Mirador based on the ceramic assemblage and architecture. Significant continuity and stability of the pottery making community is reflected in the ceramic assemblage. Additionally, it was desirable to gain an understanding of how the Terminal Classic occupation at El Mirador differed from other Maya cities. The comparisons show that on a general level, despite being a small settlement, El Mirador participated in many of the cultural patterns that characterize the Terminal Classic period. Two levels of ceramic production are postulated for the Late Classic period, one sustaining production of fine wares (polychromes) and the other sustaining production of basic production (utilitarian wares). The people inhabiting El Mirador in the Terminal Classic period were materially less well-off, and did not pursue activities associated with high culture as their counterparts did in larger cities. Nevertheless, they were not culturally isolated and they had access to trade items and small quantities of prestige goods.

In order to maximize fitness, individuals must partition their limited resources among competing physiological processes, creating negative statistical associations between processes known as “life-history trade-offs”. Evidence indicates that individuals tend to decrease their reproductive investment when confronted with a significant immunological challenge in order to increase investment in immune defense. This trade-off is often accompanied by a significant decrease in the sexual signal, which provides an honest signal of the male’s infection status to potential mates. However, if individual residual reproductive value is low, they may instead increase their reproductive investment to maximize reproductive success before the end of their life (a.k.a. terminal investment). Here, we investigate the potential for terminal investment in the ground cricket Allonemobius socius by inoculating males with varying dosages of an immune challenge. We predicted that both high dose and advanced male age would induce terminal investment. Furthermore, we predicted that terminally investing males would produce a dishonest signal by increasing their signaling effort. We found that upon infection We found that upon infection, young males and old males differentially alter their reproductive strategy. Young males exhibited the classic deceleration of reproductive effort. However, old males increased their calling song energetics and decreased their parental investment (nuptial gift size), suggesting that old males are dishonestly signaling their condition to the female.

<p> This thesis is an investigation of some of the aspects of costing and machining that are applicable to numerically controlled (N/C) machine tools with particular reference to the facilities at McMaster University,and is divided into two sections. </p> <p> Section A is a brief discussion of the suitability of N/C for simulation methods and a review of the principles of metal cutting and the problems involved in estimating costs. A method is devised to simulate the machining of "typical" parts that have been generated by a random strategy. The results of the simulation were used to find a relationship between the geometric parameters of each part and the time required for all the machining operations to make that part, this relationship was called the "complexity factor" for the part. Sugestions for possible future extensions to the work were made.</p> <p> Section B is a feasibility study for increasing the range of use of a Moog point-to-point N/C machine to contouring, using the computer facilities available at McMaster University. It was proposed to produce a numerical control tape to machine a general oval based on a method of approximate linear interpolations using an on-line, time sharing computer terminal and a PDP "mini computer". The contouring method was tested by machining a circular groove (an oval with equal major and minor axes) and measuring the accuracy. The possibility of extending the work to other contours and three dimensional solids is discussed.</p> / Thesis / Master of Engineering (MEngr)

<p> Although remote sensing has been used in certain aspects of transportation studies, it appears that little attention has been given to its application in parking assessment. For this reason, a study has been undertaken to demonstrate that oblique aerial photographs can be effectively used to investigate.parking characteristices in shopping plazas, in particular to determine the rates of occupancy and turnover that occur in the available parking stalls. From a light aircraft and a helicopter, panchromatic prints and colour slides of two shopping plazas in Dundas and Hamilton, Ontario, were taken with hand-held 35 mm cameras. Photographs were taken every 15 minutes over a period of 1 hour. A comparison of the films used indicates that the presence of colour in the slides permits easier differentiation between vehicles and hence easier identification of the changes that occur at each parking stall. Procedures for extracting and recording data from the photographs and analysing the results were described. In addition to obtaining information on occupancy and turnover, it is demonstrated that the aerial view permits on excellent assessment of the effectiveness of the vehicular system. The ease of vehicle movement, the effectiveness of signing, parking stall preferences, the occurrence of illegal parking and the separation of delivery vehicles and passenger cars can all be deduced from the photography. </p> / Thesis / Candidate in Philosophy

<p> The design of a flexible, high speed, raster scan graphics terminal is presented. The design is presented in general architectural terms rather than from a detailed circuitry point of view.</p> <p> Control is divided between the 'main' microprocessor, an Intel 8086, and a subservient graphics controller which consists of a microprogrammable, bit-sliced, AM2903/2910 special purpose microprocessor. The high speed graphics controller is microprogrammed to accept basic line and circle generating commands. The configuration is felt to represent an efficient balance between simplicity and speed.</p> / Thesis / Master of Science (MS)

In order to facilitate a biophysical analysis of the carboxy terminal acidic transactivation domain (AAD) of Vmw65 from Herpes Simplex Virus Type 1 (HSV-1), an overexpression system in Escherichia coli was constructed and optimized to produce milligram quantities of this polypeptide. Purification of the polypeptide was facilitated by creating a fusion protein to glutathione S-transferase (GST) from Schizosoma japonicum using a commercially available vector. Upon thrombin digestion of the fusion protein, the carrier and AAD products were resolved by anion-exchange chromatography. With typically 15 mg of AAD available from a 12 litre culture, several biophysical studies were initiated. Circular dichroism and fluorescence spectroscopy both described a polypeptide with an extended structure reminicent of a random-coil; that is, it did not possess substantial quantities of known elements of secondary structure such as a-helicies and β-sheets under physiological conditions. A new structure high in α-helical content was induced upon addition of trifluoroethanol to mimic a hydrophobic milieu. Ultracentrifugation data supported the spectroscopic observations by describing an extended, monomeric polypeptide. The ultimate goal of the study, a teritiary structure, was sought by attempting to crystallize AAD with popular salts and organic solvents. Biologically, the described random-coil structure of AAD could be relevant to its role as a promoter and stablizer of the transcriptional pre-initation complex, the determining step in gene expression. A structurally labile domain would support AAD’s ability to interact with several targets including TFIID and TFIIB, though not necessarily by similar mechanisms. The requirement for a drastic conformational change such as a random-coil to α-helical transition currently remains unclear though observations made in this study of AAD in trifluoroethanol have shown that a conformational change is indeed possible. With a means of producing large quantities of AAD, the opportunity now arises to study its interaction with available cloned targets. The ensuing biophysical studies will then provide a greater understanding of AAD’s important role in gene expression. / Thesis / Master of Science (MSc)