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Behavioral Ecology And Associated Virology Of Mosquito-Host Interactions In Southern California, Oliver Eshun

Loma Linda University Electronic Theses, Dissertations & Projects

Elucidating characteristics of mosquito-host interactions are critical for understanding the ecology and epidemiology of mosquito-borne diseases. In this dissertation, I conducted three studies to explore potential mosquito-host interactions and associated virus infection rates. I first demonstrated that mosquito captures at CO2-baited traps decreased most markedly with height above ground, and also decreased with distance from water at a riparian area but not at an open water source lacking a vegetated border. Birds might therefore prefer elevated nests or roosts to avoid mosquitoes. The second study examined the anti-mosquito behaviors of budgerigars (Melopsittacus undulatus) in a laboratory study. The birds defended …

Baylisascaris Procyonis Prevalence And Impact In Raccoon (Procyon Lotor) Populations, Matthew Ingle

Loma Linda University Electronic Theses, Dissertations & Projects

Baylisascaris procyonis is a nematode parasite that infects the small intestines of raccoons (Procyon lotor). Raccoons are the definitive host for this parasite, which can have both an indirect and direct life cycle. In intermediate hosts, the parasite causes serious pathology resulting from larvae migrating through host tissue to the brain. Infection via exposure to B. procyonis eggs is fatal in over 90 vertebrate species that serve as intermediate hosts, including humans. The zoonotic potential of B. procyonis makes understanding factors that impact prevalence and pathology in raccoons important for management strategies. Alimentary canals from 226 raccoons trapped in nine …

Vegetarian Dietary Patterns: Mortality, Colorectal Cancer, And Food Consumption, Michael John Orlich

Loma Linda University Electronic Theses, Dissertations & Projects

Objective Vegetarian dietary patterns represent longstanding, real-world diets consumed by a minority of persons. Studies of important health outcomes of such diets, particularly for all-cause mortality and colorectal cancer risk, have yielded inconsistent results. We sought to examine these outcomes (mortality and colorectal cancer incidence) in a large North-American cohort. We also sought to further characterize potentially important differences in the food consumption patterns of these diets. Design Baseline diet was measured by a quantitative food frequency questionnaire among more than 96,000 Seventh-day Adventists in the US and Canada, enrolled from 2002-2007. Dietary patterns were defined, based on the reported …

The Effects Of Physical Activity And Nutrient Intake On The Risk Of Hip Fracture : Results From The Adventist Health Study-2, Wen-Ling Liao

Loma Linda University Electronic Theses, Dissertations & Projects

This is a two year of follow up study of Adventist Health Study-2 (AHS-2). We assessed the association between physical activity, nutrient intake and risk of hip fracture among peri- and post menopausal Caucasian women using unconditional logistic regression models. All subjects completed a lifestyle questionnaire which including information of physical activity and frequency and portion size of food intake at enrollment into the study (2002-2007). The “Bi-Annual Hospitalization History” questionnaire which included a question about hip fractures due to minor trauma/falls was sent to subjects approximately two years after enrollment, with a response rat of 82.84%. In this cohort, …

Spatial Ecology Of The Desert Tortoise: Sampling Frequency And Biological Influences, Meagan L. Harless

Loma Linda University Electronic Theses, Dissertations & Projects

Understanding the spatial ecology of an animal is crucial for making positive efforts to provide for its recovery. As a part of this understanding, home range estimates are used to answer a variety of questions in ecological studies. However, home range estimates based on a collection of radio-telemetry locations are sensitive to methodological variables, such as sample size, sampling frequency, and the choice of estimator. Further confounding these estimates are a number of physical, social, and ecological factors. Identifying the main determinants of space use patterns by a species may aid conservation efforts.

The Desert Tortoise (Gopherus agassizii)of the …

Responses To Salinity Of Color Polymorphs In Two Populations Of The Sea Star, Pisaster Achraceus, Viren Johann Perumal

Loma Linda University Electronic Theses, Dissertations & Projects

Pisaster ochraceus was analyzed to determine if varying salinities, animal color, or location affect the physiology of these sea stars. The three responses analyzed were aerobic respiration, ammonia excretion, and self-righting. The tested variables included two different color morphs (orange and purple) of P. ochraceus, two different locations (open coast and inland straits) in Washington State, and three salinities (22, 30, and 40 psu).

Wet mass-specific oxygen consumption rates were not significantly affected by color, location, or salinity, and Dry mass-specific oxygen consumption rates showed no significant differences for main effects, but a three-way interaction was identified. Similarly, ammonia …

Systematics Of The Endangered Mauremys Mutica And Mauremys Annamensis, Jonathan Julio Fong

Loma Linda University Electronic Theses, Dissertations & Projects

Almost all turtle species in Asia are going extinct due to the demand for turtle products as food and medicine. A difficulty in creating effective conservation measures is that very little is known about the evolutionary relationships between populations and species. It is believed that several lineages we are currently calling species could in actuality be a complex of several species. One of these supposed species is the Yellow Pond Turtle, Mauremys mutica. Previous research has shown this group to have a tremendous amount of morphological and molecular diversity. In this study, I have used a combination of known-locality, farm, …

Primary Prevention Healthcare Among Black American Men: Social Ecological Factors Predictive Of Prostate Cancer Early Detection Access, Virginia Diane Bush Agbonkhese Woods

Loma Linda University Electronic Theses, Dissertations & Projects

Access to healthcare requires individuals to have a place to go, a healthcare provider to see them, resources to obtain proper care, and the appropriate health services given in an appropriate timeframe. Non-Hispanic Black American men have the highest incidence rate of prostate cancer in the world, 180.6 per 100,000 (NCI, 2004). It is not clear as to why high rates persist, but higher death rates are associated with late detection. This mixed-methods ecological study was to investigate physician and Black male perceptions and practices regarding prostate cancer early detection with prostate specific antigen (PSA) blood test, and the digital …

Depth Profiles And Soil Textures Of The Vernal Pools Of The Santa Rosa Plateau Preserve, Riverside County, California, Ralph Charles Workman Jr.

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this project was to study the edaphic and topographic characteristics of the 13 vernal pools on the Santa Rosa Plateau Preserve, thus documenting the role soil texture plays in vernal pool formation.

Several field and laboratory procedures were used to demonstrate that there is a higher percentage of clay present within vernal pools than in soils outside the margin of the pools, for 11 out of the 13 pools. Statistical tests showed that the percentage of clay was highly significant within the center soil of the pool as compared to the soil outside the margin of the …

Case-Control Study Of Vitamin A Intake And Colorectal Cancer In Seventh-Day Adventists, John William Morgan

Loma Linda University Electronic Theses, Dissertations & Projects

Colorectal cancer is the second most common cause of cancer deaths in Americans; producing approximately 60,000 deaths in Americans each year. Studies of high and low risk populations have suggested a dietary etiology for colorectal cancer, although investigations of specific dietary factors have produced inconsistent results.

Population based studies of California Seventh-day Adventists demonstrate dietary variety regarding factors suspected as important in the etiology of colorectal cancer. These studies document a substantially reduced mortality and incidence from colorectal cancer in Seventh-day Adventists when compared to other California Populations. Although specific reasons for this difference remain obscure, the 'Unique lifestyle and …

Field Behavior Comparison Of 8 Species Of California Desert Ants, Jack S. Neal

Loma Linda University Electronic Theses, Dissertations & Projects

Replicate colonies were observed at three study sites in southern California. Hourly activity was monitored during winter and spring.

The time outside the nest ranged from strictly diurnal in Pogonomyrmex californicus to bimodal to nocturnal in Pheidole barbata. Four aspects of surface activity, foraging, nest work, patrolling, and convening, also differed among species in hour and/or in relative proportion of such activity. Finally, interesting species differences were seen in climbing ability, running time between stops, and response to air blasts (Messor oergandei and Pheidole barbata were the least aggressive). Solenopsis maniosa was one of the three worst glass climbers, along …

A Behavioral And Ecological Study Of The Fiddler Crab Uca Crenulata, Magali Hantson-Parker

Loma Linda University Electronic Theses, Dissertations & Projects

The social interaction and behavioral activities of a population of fiddler crabs, Uca crenulatat located in the "Aqua Hedianda" lagoon in Carlsbad, California, is the subject of this study.

Variations in environmental factors as well as seasonal behavioral changes cause an important fluctuation in the male to female ratio and in population density.

A daily and seasonal variation is observed in the different behavioral activities displayed by the crab colony and are caused by biotic and abiotic environmental factors and by intrinsic hormonal changes.

A male color variation from dark to light is related to behavioral changes during the breeding …

Resource Partitioning In Seven Species Of Sympatric Intertidal Chitons (Mollusca: Polyplacophora), Richard D. Piercy

Loma Linda University Electronic Theses, Dissertations & Projects

Space (intertidal height and location/exposure on the rock surface), and food {gut contents) were partitioned among 7 species of sympatric intertidal chitons: Mopaliidae - Mopalia hindsii, M. ciliata, ~· lignosa, M. muscosa, and Katharina tunicata; and Ischnochitonidae - Tonicella lineata and Cyanoplax dentiens. Species distribution relative to intertidal height (-0.3m to +0.9m) showed significant differences. M. hindsii, ~· ciliata, M. lignosa, and T. lineata preferred slopes or undersides of rocks while ~· muscosa, K. tunicata, and c. dentiens occurred on the top horizontal surfaces or in more exposed habitats. Chitons differed significantly in their associations with Lithothamnion, macrophytic algae, Ulva, …

Distributional Ecology Of Vegetation In The Vernal Pools Of The Santa Rosa Plateau, California, John A. Rosario

Loma Linda University Electronic Theses, Dissertations & Projects

Interpool distribution studies of 10 vernal pools on the Santa Rosa Plateau found area to be the best single predictor of species richness in each type of regression model evaluated. Area predicted most accurately in a mixed linear-curvilinear regression model (y = a + b log x). Area appeared to reflect ecologic diversity, because multiple linear regression models provided better predictions of species richness using combinations of physical characteristics which excluded area from the regression equation. In addition, species turnover was demonstrated in a single vernal pool that was evaluated.

Intrapool distribution was studied along a soil moisture/microtopographic gradient in …

Environmental Cues In The Seasonal Development Of The Southern California Annual Grassland, George E. Johnson

Loma Linda University Electronic Theses, Dissertations & Projects

Annual grasslands characteristically experience a succession of seasonal phases which provide for the coexistence of various species by allowing them to make their major demands upon environmental resources at different times. Thus, an ecosystem furnishing certain resources at a limited rate is enabled to support a larger total biomass.

The grasslands of southern California consist principally of annual grasses coexisting with the few remaining native perennial grasses. Characteristic also is the inclusion of forbs which are distinctly either early spring or late summer plants. Many spring forbs, annual grasses, and summer forbs are observed to germinate in approximAte unison shortly …

The Distribution Of Orcuttia Californica (Poaceae) In The Vernal Pools Of The Santa Rosa Plateau, Riverside County, California, Cluney M. Stagg

Loma Linda University Electronic Theses, Dissertations & Projects

Ecological studies were conducted on the rare annual grass Orcuttia californica (Vasey), an endemic to California, from April to September, 1976 in 11 vernal pools located on the Santa Rosa Plateau in Riverside County. To help determine why Orcutt grass occurs in only 6 of the 11 pools and more specifically why it only occurs in patches within a given pool, biweekly measurements of frequency, density and phenology were taken within each of a total of 28 circular plots (r = 10 meters) in 5 pools. This data was related to concurrent biweekly measurements of soil moisture, soil texture and …

Daily Nest Opening And Closing Of The Ant Pogonomyrmex Californicus, Lynn R. Heath

Loma Linda University Electronic Theses, Dissertations & Projects

In a study of timing in this ant ten of the twelve nests which were observed opened synchronously in the morning and closed in the evening. However, one was never seen to close and another closed during the day and stayed open at night.

A seasonal progression was shown by later opening times and earlier closing times. Opening and closing temperatures at the surface of the ground and three inches deep showed no seasonal progression.

In most cases the days when the nests opened the earliest the temperatures at opening time were the highest.

Soon after nests had closed they …

Nocturnal Flights Of Triatoma Protracta (Uhler) As Indicated By Collections At Black Light Traps : (Hemiptera: Reduviidae: Triatominae), Robert D. Sjogren

Loma Linda University Electronic Theses, Dissertations & Projects

An investigation into the environmental and ethological factors relating to summer flights of Triatoma protracta protracta (Uhler) was performed utilizing black light traps of original design. Field observations were conducted on 51 evenings during the period June 1 to October 31, 1964. The traps were operated on a surveillance basis for the remainder of a twelve month period.

A total of 398 adult Triatoma protracta were collected in traps around a residence located in the chaparral covered foothills 10 miles east of Redlands, California. In addition to observations on field behavior, laboratory dissections were performed on each bug to obtain …