Biologists often trap animals to obtain information on them. If trapping is selective toward some animals, the information may be inaccurate. Most mammalogists know or suspect that their trapping techniques (reviewed by Hayne, 1949; and Stickel, 1954) contain sources of bias. Since trapping remains the only feasible way to obtain information on many animals, researchers have tried to discover sources of sampling error and refine their techniques. They have found that one major source of difficulty may lie in the behavior of animals. Individual animals seem to respond differently to trapping, both initially and through learning (Geis, 1955; Crowcroft and Jeffers, 1961; and others). However, researchers seldom observe the behavioral responses of animals to traps. They infer information from capture data. Perhaps an empirical approach would shed more light on the relationship between behavior and trapping. The present study is such an approach. The study concerns the behavioral responses of adult Uinta ground squirrels, Citellus armatus, to trapping. I based the study on the direct observations of known individuals in a wild population. My primary objective was to learn how animals respond to a trap, to capture, and to recapture. My approach was both that of a population ecologist interested in factors affecting trapping success and that of a behaviorist interested in the effect of trapping procedures on the behavior of animals. I conducted a broad ecological and behavioral study of the population (Balph and Stokes, 1963) before beginning the research on trap response, which helped me select parameters and develop procedures. I also conducted a pilot study on deer mice, Peromyscus maniculatus, in the laboratory to test some procedures and the design of the trap-response investigation.

Thesis (Sc.D.)--Massachusetts Institute of Technology, Dept. of Civil Engineering, 1981. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING. / Vita. / Bibliography: leaves 420-431. / by John Mei-Ming Ting. / Sc.D.

Advanced nondestructive inspection techniques like stress wave timing and resistance microdrilling have been used to successfully inspection timber bridges, but it is most effective on girder style bridges. There is a noted need to develop additional inspection techniques for longitudinal deck/slab timber bridges, which comprise about 20% of the national bridge inventory. One technique that holds potential is ground penetrating radar, a recognized nondestructive testing technique that has been used effectively for many different environmental and transportation applications. It has been utilized successfully to identify buried objects, internal defects and material changes. The objective of this research was to assess the potential for using GPR to identify and assess simulated deterioration in longitudinal timber deck timber bridges. GPR scans were completed in the longitudinal and transverse directions of a screwlaminated timber bridge deck before and after a bituminous layer was added to assess embedded defects that simulated voids, decay, insect damage and horizontal shear splitting. Assessment of the GPR wave energy signal was completed using visualization software that was provided with the commercial GPR unit used for the testing. The radar signal was analyzed in both the longitudinal direction (antenna front to back) and the transverse direction (antenna side to side). Interpretation of the radar signals allowed for the identification of various internal defects present in the deck. Based on the results, GPR has the potential to identify internal defects in timber bridge decks before and after a bituminous layer was added. Large, rectangular void defects (at least 6? by 12? by 5 in. (15.2? by 30.4? by 12.7 cm)) that were hollow, filled with foam, or filled with sawdust/adhesive were most easily identified under all scanning conditions. The addition of a bituminous layer, common to slab bridge construction, damped the signal response and made it more difficult to identify defects. Several smaller defects that were found in the deck without a bituminous layer were not identified in scanning completed after the bituminous layer was added.

No description available.

Note:

A research report submitted in partial fulfilment of the requirements for the degree of Master of Science in Engineering, to the Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg, 2019 / A dynamic simulation study is a critical deliverable of a mine project feasibility study. Mining houses rely on simulation to confirm that complex, integrated systems can achieve design capacity before investment decisions are made. Dynamic simulations are powerful tools, but only if they are developed using the right methodology, and with information that has been verified. The importance of work in the field of mine dynamic simulation validation was made clear during the early stages of this research report when it was identified that there is limited information available on the subject. Work conducted in the realm of validation can make an invaluable contribution to the success of future projects undertaken around the world. The last few years have been difficult for employees of some mining companies because of looming job cuts due to high production costs, high overheads, and decreasing product demand. For many mining companies, it was a case of survival which gave rise to the development of new strategies and innovative thinking. Coal Mine A Life of Mine (LOM) extension project is a prime example of innovative thinking. In this case, the project was approved for implementation when export coal prices were on the low end of the price cycle. The dynamic simulation of the full materials handling value chain conducted during the project was of utmost importance, and provided assurance to the project review team that annual production targets can be achieved. The simulation development methodology was based on a unique approach that reduced time spent on the simulation through the integration of different, independent models that represented sub-systems in the materials handling value chain. There was, therefore, a strong need to validate the simulation, which could lead to the adoption of this approach on future projects. In this research report, the LOM extension project scope and the mining activities conducted by Coal Mine A are explained, and a brief, but interesting history of Modelling and Simulation (M&S) is provided. The subject of M&S is vast and has evolved into its own separate discipline. M&S is an invaluable tool, and the importance of verification, validation and credibility is elaborated on. The development of the simulation and the inputs and outputs of the simulation are discussed before the validation effort. The work conducted on the validation aimed to confirm the accuracy of the simulation unequivocally. Although the production target was not achieved as predicted by the dynamic simulation during the period of validation, there was an indication that the materials handling value chain could perform as predicted as each of the individual sub-systems had achieved the design capacity. Problem areas were identified which could be attributed to the poor performance, and if these areas are addressed, the system could perform as predicted by the simulation. This confirms that dynamic simulation can add value to predictions about mining system performance such that informed decisions can be made. / TL (2020)

No description available.

Today, biodiversity is one of the most studied disciplines because it encompasses all species of plants, animals, and microorganisms that exist and act within an ecosystem. In recent decades, biodiversity has been degrading rapidly due to the simplification of agricultural systems, and the irrational use of pesticides that alter the normal function of ecosystems. Within nature, each insect population is attacked by one or more natural enemies. In this investigation, during a six month period from June to December 2006, the biodiversity of predatory insects from the syrphidae and carabidae families was determined in three ecological niches of three communities with two posed risks (Malaise and Pitfall) for the Carabidae family and one (Malaise) for the Syrphidae family. This investigation presents the differences in composition of morphospecies from three ecological niches in three communities of the yungas of La Paz. In total, we recorded 67 morphospecies from the Carabidae family in a population of 1107 individuals and 38 morphospecies from the Syrphidae family in a population of 1333 individuals. From the data above, it was found that the most diverse community was San Juan de la Miel with 33 morphospecies from the Syrphidae family and 42 morphospecies from the Carabidae family. However, in the case of the Syrphidae family, a smaller quantity of individuals found were related to the other communities whereas in the case of the Carabidae family, a larger quantity of individuals found were related. The similarity indices show only around 8-15% between the different ecological niches and communities which is relatively low and indicates that dominant species exist in these ecological niches, whether in the forest or in cultivated areas. The Carabids are insects similar to beetles, coming in varied sizes and colors, with dark and bright metallic colors being the most prominent. The family contains between 20,000 and 30,000 known species. The Syrphids are similar to dipterous insects, coming in different sizes and colors. Generally, black and yellow, or a combination of both similar to bees, are the most predominant colors. The family contains around 5,400 known species. The Carabids and Syrphids are very important in the biodiversity of ecosystems as well as in ecology because they regulate the pest populations through predation. In addition, when they are adults, they pollinate crops thus reducing the use of petrochemical insecticides. The area studied has a good diversity of species due to the geomorphology of the site. It has small patches of crops and fallow land surrounded by forests that allow the maintenance of its diversity, which is very important for the balance of ecosystems.

The use of geophysical tools to locate clandestine burials involving bodies has seen increasing popularity among forensic personnel. Often, these search methods are important to highlight certain areas where a body may or may not be located prior to utilizing invasive search techniques. Because of the success of these tools within real-life forensic searches, the use of controlled studies that monitor and detect cadavers over certain lengths of time have been increasingly utilized. However, these controlled studies have not monitored various burial scenarios that mimic real-life situations. This study focused on detecting and monitoring six burials containing pig carcasses used as proxies for human bodies and two control burials with a conductivity meter and ground-penetrating radar (GPR) with a 500-MHz and a 250-MHz antenna over a twelve month period. Each burial within this study represented a different forensic scenario that mimicked a real-life situation. Further, forensic use of GPR in both controlled settings as well as real-life searches have mainly focused on the use of a 500-MHz antenna. Therefore, this research also compared the use of a 250-MHz antenna with a 500-MHz antenna. Lastly, a number of GPR imagery options were utilized including reflection profiles and horizontal slices with various GPR software programs to compare the results obtained. Results obtained from the conductivity meter were compared to the results obtained by both antennae of the GPR. Overall, the use of multiple GPR imagery options provided increased resolution of the burial scenarios. Results showed that the conductivity meter was not a beneficial geophysical tool because none of the burial scenarios were detected. On the other hand, the use of GPR showed that the graves with objects added to the pig carcasses provided iv increased resolution compared to the graves containing only pig carcasses. Lastly, the 250-MHz antenna provided better resolution of the burial scenarios than the 500-MHz antenna due to easier discrimination of the forensic targets. Therefore, the use of a 250-MHz antenna would be a viable option to search for clandestine burials containing adult-sized bodies

Sexual selection is considered a powerful evolutionary force responsible for the enormous diversity found in reproductive morphology, physiology, and behavior. I addressed questions related to selection in the Cape ground squirrel (Xerus inauris), a species characterized as highly social and promiscuous. These attributes often are responsible for variance in male reproductive success and as such, sexual selection theory predicts increased opportunity for sexual selection. I confirm that the predominant mechanism underlying genital evolution and competition for paternity in X. inauris is sperm competition. I find evidence that investment in sperm competition is costly and may reflect immunocompetence. I quantify reproductive success as it relates to alternative male tactics and female resource distribution. I find that male X. inauris alternative reproductive tactics differ within and across populations most likely due to differences in female resource distribution. In areas where females are evenly distributed, dispersed males encounter more estrous females, and therefore have increased breeding opportunities. However, the decision to remain natal does not preclude reproduction. I determine that these tactics are most likely conditional with equal fitness payoffs. Males, regardless of tactic, invest more in post-copulatory competition (e.g. sperm competition, copulatory plugs) than males within a population with a clustered distribution of breeding females. In the latter area, males form dominance hierarchies that affect copulatory success and lead to greater skews in reproduction among males. Both sites have evidence of a highly skewed variance in reproduction and intense sexual selective pressure. My results suggest these populations have increased opportunities for selection but that different mechanisms of intrasexual competition may result in rapid evolutionary change within this species.