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Collection Description

Collection of student theses and dissertations from as early as 1939, but mainly from 2010 to present.

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A gravity and magnetic study of the Laguna Salada area, Baja California, Mexico
Plate 1; Gravity and magnetic station map of the Laguna Salada Area, Baja California, Mexico. Plate 2; Simple bouguer gravity map of the Laguna Salada Area, Baja California , Mexico. Plate 3; Magnetic vertical Intensity anomaly map of the Laguna Salada Area, Baja California, Mexico. Plate 4; A-A' gravity and magnetic profiles. Plate 5; B-B' gravity and magnetic profiles, in back pocket., A simple Bouguer gravity map, based on 775 gravity stations spaced at an average of 1 mile, is presented for the Laguna Salada area, Baja California, Mexico. The area is located in the northwest corner of the Salton Trough-Gulf of California depression. The results confirm that a regional, linear and steep gravity gradient (East Side Anomaly) is oblique to the major faults bounding the east of the Laguna Salada graben. The East Side Anomaly develops about 30 miles north of the international border, passes on the east side of the Laguna Salada basin, and opens to the east around the south end of Sierra del Mayor. It probably closes arounf the northwest end of the Sierra de las Pintas and continues south. The East Side Anomaly is suggested to be a positive effect, due primarily to a near vertical-step discontinuity in the crust-mantle interface. This discontinuity delineates the western limit of thin crust under the Salton Trough. The depth to basement in the Laguna Salada graben cannot be determined as the shape and amplitude of the positive effect are not known. The crust-mantle discontinuity, designated as East Side Anomaly, is inferred to have been originally related to the fault patterns of Cretaceous to Miocene age. The fault patterns consisted of slightly west of north, northwest and northeast trending sets. The slightly west of north set was associated with the major extension and crustal thinning of the Gulf of California depression during the Miocene. This episode gave rise to the development of the East Side Anomaly. The anomaly generally coincided with the general north-south fault trends but locally was off-set by the northwest and northeast faults. The episode of major extension and crustal thinning also resulted in the formation of a zone of horsts and grabens between the Peninsular Range and the Gulf of California depression. Most of the translation of Baja California away from the mainland probably occurred along the strike-slip San Jacinto fault. Right-lateral shear resulted in the development of the Laguna Salada, Cucapa and associated strike-slip faults to the southwest. These later strike-slip faults cut across the original fault patterns and structures, including the north end of the Laguna Salada graben. These faults also distorted and obliquely cut the East Side Anomaly as is observed at the northeast edge of the Laguna Salada graben. The area southwest of the San Jacinto fault including Laguna Salada, does not appear to be one of "spreading" as the magnetic data do not indicate any presence of intrusives in the Laguna Salada fault zone .The observed extension is due to right- lateral shear.
A grounded theory study of how postsecondary instructors construct their role in an asynchronous online course
Over the past two decades online education utilizing computer technology to facilitate asynchronous learning has become established as the dominant means of distance education (Lui, 2012). Currently, 86.5 percent of higher education institutions in the U.S. offer some form of online learning (Allen & Seaman, 2011). The nature of online instruction has been a growing focus of research in the area of online teaching and learning in order to fully assess quality online education (I. T. Chou, Saj, & Hamilton, 2010) and to better achieve online student success and satisfaction. To better understand the role of the online instructor, this study was a grounded theory investigation of the way postsecondary instructors construct their role in an asynchronous online course. Specifically, this research examined how online instructors conceptualize their role in an online course and how they enact this role through their interactions with students and use of course management system tools. Four theoretical themes and twelve sub-themes emerged from the study which serve to establish the LFSV grounded theory model for the construction of the role of the asynchronous online instructor. Suggestions for further in depth research on individual study themes and the use of study themes for quantitative studies are also presented. Keywords: online instruction, online faculty development, and online teaching and learning, San Diego State University
A growing trend: Policy diffusion of medical marijuana laws in the American states
Includes bibliographical references (pages 53-57)., There are currently eighteen American states plus Washington D.C. that have medical marijuana laws. These laws were designed to decriminalize and legalize the use of marijuana for approved medical conditions and purposes. The federal government has not recognized state medical marijuana laws as legitimate protections for the medical use of the drug. The states continue to pass medical marijuana legislation via the citizen initiative process and through the formal legislative process. The spread of medical marijuana policies in the American states has taken place over the course of nearly two decades and will likely continue. This research examines the spread of these policies and investigates the intrastate and interstate political forces that may have contributed to decision to adopt medical marijuana laws in multiple states.
A high data rate wireless brain computer interface
Brain computer interface (BCI) taps into brain state and provides an associated quantitative assessment. It has potential for the real-time assessment of a person's cognitive state. BCI is a study to analyze characteristics of brain (Electrophysiology). Electrophysiology can be categorized into Invasive and Non-invasive methods. Electroencephalography (EEG) produced spontaneously during the process of thinking with frequency bands alpha waves, beta waves, theta waves and delta waves is one of the Non-Invasive methods. Electrocorticography (ECoG) is one of the invasive methods which records mu, beta and gamma frequency bands. In single unit recording, single or multi-neuron spiking and local field potential (LFP's) are recorded. Invasive methods require surgery to implant electrodes inside the skull. A wireless interface is required to transfer brain data from BCI circuitry to host interface. Wireless transmission module eliminates the inconvenience of wiring and reduce risk of contamination. The wireless link implemented in this study has ability to switch among classic Bluetooth protocol, Bluetooth smart protocol and proprietary protocol depends on desired throughput, Power consumption and transmission distance (RSSI). Invasive methods like single unit recording requires processing high frequency band spectrum and optimum data throughput to transmit spike data. This study proposes a high speed sampling algorithm to increase sampling rate and a proprietary wireless protocol to transmit high sample data and reduce packet error rate for physiological sensing. A low-power bio potential amplifier in BCI circuitry converts analog brain data to digital format. High sampling rate can be achieved by multi-threading software call to receive data from sense electronics. The proposed sampling algorithm proposed increases sampling frequency from 800 Samples/sec to 10k for samples 8 channels. Wireless interface which allows throughput and power optimization can be achieved by implementing transmit mode with dynamic connection interval. Packet error rate is vital parameter for data integrity and can be optimized by implementing dynamic channel shifting mechanism in the presence of noisy channel. Dynamic transmit buffer length allocation algorithm should be implemented for better utilization of channel.
A high resolution paleoseismic study in the southern San Jacinto fault zone, Imperial Valley, California
The southern San Jacinto fault zone consists of three main fault strands or segments: the Coyote Creek (CCF), Superstition Mountain (SMF) and Superstition Hills (SHF) faults. The CCF is divided into northern, central and southern segments, defined after its rupture in the 1968 Borrego Mountain earthquake. The boundaries of these segments are delineated by step-overs and/or fault bends. In contrast, the segment boundary between the southern segment of the CCF and the northern end of the SMF is defined only by a l0° bend or change in strike. However, the main reason that these two faults are considered separate is that the 1968 rupture terminated along the southern segment of the CCF. The only way to demonstrate how individual segments have behaved in the past and how segment boundaries work is to resolve their past rupture histories through high-resolution paleoseismic studies. We studied the earthquake history of the northern SMF to obtain a complete record of how and which boundaries have controlled past ruptures. We exposed faulted sediments of the regionally extensive Lake Cahuilla at Carrizo Wash along the northernmost SMF, and correlated the stratigraphy and earthquake history to sites along the CCF using radiocarbon dates and sequence stratigraphy. We exposed a 5.5 m-thick section of very well stratified fluvial, deltaic and lacustrine sediments, part of which have been ruptured by the fault. Six and probably seven surface rupturing events have been identified in this section but none of them affected the last two lake Cahuilla high-stand deposits, indicating that the northern Superstition Mountain fault has not ruptured for at least 330 years and possibly as long as 500 years. Using high resolution 3D trenching techniques we obtained information of fault geometry and slip for the last three ground rupturing events. The last earthquake rupture (event V) consisted of en echelon faults with a minimum horizontal displacement of 6 to 9 cm of slip in each segment, which sums to a minimum total slip across the fault zone off 15cm ±4cm. Events 2 and 3 (events T and R) are concentrated in a narrow fault zone that displace a channel margin about 6±1 m. The slip measured for events T and R at Carrizo Wash may represent three separated events, but fluvial erosion related to units 180-195 have apparently removed evidence for the additional event. Based on radiocarbon results alone, this larger earthquakes dates between A.D. 1085 and 1680. Correlation to Gurrola and Rockwell's (1996) site 2 km south along the SMF suggests that the penultimate event at Carrizo wash correlates with the two last SMF events between A.D. 1280 and 1680 (Gurrola and Rockwell, 1996). This is essentially the same result as for the southern CCF, suggesting that in most large earthquakes, the SMF and southern CCF rupture together. In contrast, the central CCF has ruptured repeatedly during the past 300 years whereas the southern CCF ruptured only in 1968. It thus appears that the southern CCF is actually the northern end of the SMF and the 3 km step-over separating the central and southern strands of the CCF is the primary structural and seismic boundary., San Diego State University
A high throughput multiplexed platform for monitoring proteolysis in the classical secretory pathway -- Search for novel antivirals
Includes bibliographical references (pages 32-35)., RNA Viruses such as Human Immunodeficiency (HIV) and Dengue Virus (DenV) cause devastating diseases, including Acquired Immunodeficiency Syndrome (AIDS) and Dengue Hemorrhagic Fever. With 2.5 and 50 million new infections yearly, respectively, unsuccessful attempts at vaccine development and resistance to current treatment, all beg for novel antivirals. However, new methods and platforms are required to increase the chances for their discovery. The classical secretory pathway is essential for biological functions and is utilized for the transport of proteins to the cell surface and/or extracellular matrix. Within the secretory pathway resides an array of enzymes that modify proteins into their mature and active forms. Viruses, as well as other pathogens, hijack such enzymes for their own benefit. While HIV and DenV are distant viruses, both rely on the cellular protease Furin within this compartment for maturation of their viral envelopes. Importantly, blockade of Furin processing leads to non-fusogenic virions, making it an ideal drug target. In order to monitor proteolysis within the natural milieu of the secretory pathway, an assay with a robust and quantitative read-out was developed. The assay relies on a complex scaffold molecule targeted to the Endoplasmic Reticulum for transport to the cell surface. A substrate is flanked by the FLAG and HA tags fused to the N-terminus of the scaffold. In such a way, in the absence of proteolysis both tags are presented on the cell surface but only one tag (HA) is presented if proteolysis occurs. Tag presentation can be subsequently detected by fluorescent-coupled antibodies in a robust and quantitative manner through flow cytometry and/or microscopy techniques. The assay described has been adapted to monitor processing of the HIV envelope and DenV pr-M proteins. It has been further calibrated in a 96-well plate format for flow cytometry, to demonstrate both robustness and repeatability, critical for high throughput screening. In addition, varied intensities of a stably expressed fluorescent protein were used for genetic barcoding through retroviral technology. Genetic barcoding was exploited to further develop the platform in a multiplexed format to assay multiple substrates in the same well. A robust platform such as the one described here will expand high throughput capabilities in search for novel antivirals and can additionally be adapted to other substrates in the secretory pathway.
A histological analysis of a Late Formative Period population from Cerro de la Cruz in the lower Río Verde valley, Oaxaca, Mexico
Samples for this histological analysis (DCIA) were collected at el ex-Convento de Cuilápam de Guerrero during the 2014 field season in Oaxaca, Mexico. The 28 individuals (45 teeth) belong to the Late Formative site of Cerro de la Cruz (400BCE - 100CE), which was originally excavated in 1988 as part of the Río Verde Formative Project. Cerro de la Cruz is an important site, as it represents one of the earliest transitions from a hunter/gatherer subsistence into an agricultural subsistence. The site consists of three habitation areas, Zone A (22 individuals) a public cemetery while Zone B (2 individuals) and Zone C (4 individuals) contain domestic burials. The Dental Cementum Increment Analysis (DCIA) provided challenges, answered questions proposed in this thesis, and provided previously unknown data (season of death). Originally it was unknown if samples from this region and time period would provide any results. Preservation of the samples was the biggest concern and after analysis, this thesis shows that teeth from an archaeological context of great antiquity can provide an age and season of death. In answering the questions proposed, it was shown that an individual’s burial location was not influenced by sex, age, body position, or season of death (p-value >= ⍺/.05). Second, a reliable age estimate was provided for 23 individuals (n=28 total) and for 24 individuals (n=28 total) a season of death was determined. Third, DICA analysis shows a greater number of summer deaths (n=15) than winter deaths (n=9). This new information suggests a greater susceptibility to infection and disease during the rainy season (summer). Finally, it was shown that age estimates from DCIA and estimates from other skeletal elements agree on the majority. All together this histological analysis has contributed to the bio-archaeological understanding of the people from Cerro de la Cruz., San Diego State University
A history of metal transport to reservoir sediments in New Haven, Connecticut
Sediments obtained from two reservoirs, Lake Whitney and Lake Saltonstall in New Haven, Connecticut, were dated radiometrically and analyzed for heavy metals. The anthropogenic fluxes were calculated and compared with possible sources in the area. Lead isotopic ratios indicate that the automotive exhaust emissions were the primary lead source in Lake Whitney. High copper levels in the sediments resulted from CuSO4 additions to the waters to control diatom and algae growth. Other metals were probably introduced atmospherically to the reservoir by several different point sources which include fossil fuel burning and industry. Aside from copper and lead, Lake Saltonstall's trace metal patterns exhibit increases parallel with East Haven's population growth. Differences in the mineralogy of the reservoir sediments were attributed to drainage and variations in the local geology., San Diego State University
A history of the British Museum's repatration debates of the Parthenon and Benin bronzes
For the last two centuries, much of the ancient Parthenon marble sculptures have been housed in the British Museum. For the past century, the museum has also displayed bronzes from Africa’s western coastal Benin region. These cultural objects have been part of repatriation debates in Britain for several decades. Many have argued that the objects should stay in the museum, as it promotes education of different cultures and civilizations. Others oppose on the grounds that the objects were stolen and belong to the country from which they originated. Since the early nineteenth century, British newspapers have reflected the marbles’ repatriation debates. They reveal the rationale of why the objects have stayed in the British Museum despite ongoing controversy. A British Parliamentary report from 1816 also provides detailed analyses of the marbles’ acquisition and their artistic integrity, which became a basis for their benefit to Britain’s cultural arts. Additional Parliamentary reports and newspapers have also provided details about the restitution debates of and claims for the Benin bronzes. A chronological narrative of the two different cultural objects illustrates how the debates and the institutional responses to those debates progressed over many decades. One can identify how and why opinions and reactions to repatriation arguments unfolded over time, and how they varied between the objects during the same time. Although the museum’s retention of the marbles and bronzes have been involved in major discussions for decades, very little scholarship has touched on the nature and evolution of these arguments. Predominantly British primary sources illustrate that the British Museum has persisted in retaining the marbles and bronzes because they benefit world culture by remaining in a major international museum. Analyzing the objects’ acquisitions and the history of their repatriation debates demonstrate what may be the cause for successful and unsuccessful repatriation requests. Immoral or illegal circumstances of acquisition certainly play a part in increasing chances that objects are sent back to where they were taken. More significantly, how culturally valuable an institution believes objects are to their collection and visitors also determine the outcome of repatriation decisions., San Diego State University
A history of the development of industrial arts at San Diego State College from 1902 to 1953
In writing this thesis, it has been my intent to reproduce in a logical order the events leading to the present status of industrial arts at San Diego State College. This study comprises the period from 1898 to 1953. During this period San Diego Normal School, later to become known as San Diego State Teachers College, and presently San Diego State College, has shown a steady and almost continuous growth. It is the purpose of this study to give the reader a better understanding of the general growth of industrial arts at San Diego State College., San Diego State College, Digitization of this archival thesis was made possible through a generous donation from Robin B. Luby.
A history of trace metal pollution in the Tia Juana River Estuary, San Diego County, California
The Tia Juana River Estuary is located in the portion of the Tia Juana River flood plain north of the United States-Mexico border, known as the Lower Tia Juana River Valley. The opening of the estuary to the Pacific Ocean is 1.5 km north of the international border. The estuary is composed of a series of narrow tidal channels which radiate from a restricted opening to the ocean in northerly, southerly, and easterly directions. The Tia Juana River flows in a westward direction and empties into the central portion of the estuary. Five sediment cores were taken, four from different tidal channels within the estuary and one from the Tia Juana River. Anthropogenic inputs were found for the following metals in all four tidal channels: Pb, Zn, Cu, and Ni. Low anthropogenic levels were detected for Fe and Cd in several of the tidal channels. The upper portion of each tidal channel has an organic-rich black silt layer thought to be related to increased population and industrialization within and adjacent to the Tia Juana River Drainage Basin within the last few decades. It is in this region that the above-mentioned metals reach their highest values. Mn is apparently mobile in this region and may possibly scavenge some of the Pb, Zn, and Co as it migrates to more oxidizing conditions, possibly forming an Mn carbonate. Compared to other sediments associated with water systems near industrialized-urbanized areas of California and the eastern United States, the Tia Juana estuarine sediments are less polluted. No specific point sources could be identified for the anthropogenic metal inputs to the Tia Juana Estuary. Possible sources include: (1) urban runoff within the Tia Juana River flood plain during storms, (2) raw sewage, derived mainly from the city of Tijuana, entering the estuary via the Tia Juana River, (3) deposition of airborne particulates related to burning of fossil fuels, and (4) automobile traffic., San Diego State University