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- Creator:
- Percolla, Marta I.
- Resource Type:
- Thesis
- Campus Tesim:
- Bakersfield
- Department:
- Biology
- Creator:
- Yanez, Ivette
- Resource Type:
- Thesis
- Identifier:
- 10047
- Campus Tesim:
- Bakersfield
- Department:
- Biology
- Creator:
- Wilder, William H
- Description:
- The Goraori acetylthiocholine technique was used to investigate the distribution of cholinesterase in fourth instar larvae of Culiseta inornate (Nilliston). Fixed and especially prepared larvae were incubated in the substrate solution for the required time, the larvae were imbedded in paraffin, and serial sections were prepared. Microscopic examination of the material revealed a strong histochemical reaction throughout the central nervous system. Faint reactions, not apparent in many of the preparations, were sometimes found associated with muscle, gastric caecae, or Malpighian tubules. The use of selective enzyme inhibitors indicated that the cholinesterase in C. inomata larvae cannot be catagorized as either acetylcholinesterase or pseudo-cholinesterase.
- Resource Type:
- Thesis
- Identifier:
- ocm64178425
- Campus Tesim:
- Fresno
- Department:
- Biology
- Creator:
- Benjamin, Christina Joyce
- Description:
- Zebrafish is an important model species to study vertebrate development. One particularly interesting aspect of fish ontogeny, which zebrafish larvae exhibit, is the high tail beat frequency up to 10 times higher than that of adult fish. Larvae therefore require a different muscle fiber type than adult fish. This study identifies the changes in muscle protein composition that might underlie this change in muscle contraction frequency. This question is interesting because contraction frequencies above 80 Hz require the so-called superfast muscles, a muscle type so far only been identified in non-locomotory muscles not required to generate significant forces. Superfast muscles are known to differ from normal fast muscles in several proteins, including myosin heavy chain. In this study we will focus on myosin, the largest protein fraction of a muscle that constitutes 40- 50% of total muscle. This study identifies and validates a protocol for myosin protein extraction and identification of myosin isoforms. Fast myosin heavy chains (210 kD) were identified in hatchlings (not yet swimming actively) and in adult Zebrafish (tail beat frequency 10 Hz). In 6-d old larvae (swimming actively, tail beat frequency 100 Hz), we found an isoform (160kD) that was identified in cat masseter muscle, which is a muscle with superfast contraction characteristics. We identified isoforms by probing Western blots with primary antibody (MYH1/2/3) against myosin heavy chains. BCA and ImageJ analysis were performed to quantify the amount of total protein and the myosin content.
- Resource Type:
- Thesis
- Campus Tesim:
- Fresno
- Department:
- Biology
- Creator:
- Houk, James L
- Description:
- Gregarines are parasitic protozoa belonging to the sporozoan subclass Telosporidia. They occur most often in invertebrate groups with a metameric level of development. Some, however, have been described from mollusks which do not have a metameric level of development (Cheng, 1967; Leger and Duboscq, 1908). The eugregarines of arthropods, including barnacles, are typically members of the suborder Cephalina. Cephaline gregarines are described as polycystid organisms to contrast them with the unsegmented monocystid gregarines. The bodies of cephaline gregarines are divided into two segments, an anterior protomerite separated from the posterior deutomerite by a membrane which does not restrict movement of the endo-plasm but does set off the nucleus in the deutomerite. A holdfast, the epimerite, is located on the anterior end of the young sporont. The gregarine remains temporarily attached externally to the cell in which it developed. It subsequently loses the epimerite and becomes a trophozoite which moves about freely, usually in the gut lumen.
- Resource Type:
- Thesis
- Identifier:
- ocm60129979
- Campus Tesim:
- Fresno
- Department:
- Biology
- Creator:
- Healer, Rain
- Description:
- The Endangered Species Recovery Program (ESRP) is supervising land restoration in southwest Fresno County through the federally funded Land Retirement Project. The reclaimed land is adjacent to currently farmed land, and there is grower concern that native vegetation on the reclaimed land will function as a reservoir for insect pest infestation. The purpose of my research was to conduct an initial inventory of Diptera present on some of the California native plants that are utilized in habitat restoration by the ESRP in southwest Fresno County. Dipteran populations were sampled on three of the species of native plants grown within the ESRP�s native plant seed nursery and on the same three plant species that also occur within non-nursery sites in the general area surrounding Tranquillity. This research provided preliminary information on dipteran trophic guilds and the potential amount of ecological redundancy present within this ecosystem. It also provided baseline biodiversity data for future research. Future work will estimate species richness, abundance, and pest/beneficial significance from this baseline data. No significant difference was found between collection sites in taxa collected, trophic guild, number of Diptera collected, and pest status.
- Resource Type:
- Thesis
- Campus Tesim:
- Fresno
- Department:
- Biology
- Creator:
- Slonka, Stephanie Marie
- Description:
- As California continues to persist in a state of severe drought, residents of the Fresno Clovis Metropolitan Area (FCMA) are slowly making changes to reduce their water usage and to be conscious of how this resource is utilized in their landscape. Since the advent of water metering in 2013 and the Governor’s declaration of California’s state of emergency, it is unknown how the response of our wildlife populations will fare, in particular, avian populations. Several studies have indicated that a long-term drought and the reduction of water availability can have adverse effects on the avian communities within a city. A pre-metering (2008) to post-metering (2015) comparison was conducted using multivariate analyses to determine how the landscape changed over time and if avian communities have responded to the “effective drought” that the FCMA is experiencing. Since pre-metering, bird abundance and the species richness of the FCMA has decreased and new habitat variables are now shown to predict bird species richness and abundance. Other essential aspects of the urban landscape that have been shown to make an impact on the bird communities had a negative response to certain socio-economic variables and there being no effect on foraging guilds in relation to certain irrigation intensities as reported in pre-metering years.
- Resource Type:
- Thesis
- Campus Tesim:
- Fresno
- Department:
- Biology
- Creator:
- Holland, V. L
- Description:
- The purpose of the present study is to gain some insight into the complex of factors that create the canopy effect with emphasis on the microenvironment that is associated with the vegetative differences. Data recorded weekly included the measurement of plant growth, precipitation, air temperature, soil moisture, and soil temperature. Other studies involved pH, bulk density, permanent wilting percentage, moisture equivalent, field capacity, organic content of the soil and. plant distribution. The determination of all factors involved was not possible in the two growing seasons studied, but accrued data suggests certain ecological relationships. The investigation was undertaken at the San Joaquin Experimental Range (SJER) near O'Neals, California, 25 miles north of Fresno. The SJER is situated on the east side of the San Joaquin Valley in the Sierra Nevada foothills. The natural vegetation is typical of the foothill woodland community (as recognized by Munz, 19&3) consisting of trees 15-70 feet tall in an open woodland with scattered brush and grassland between the trees.
- Resource Type:
- Thesis
- Identifier:
- ocm58723865
- Campus Tesim:
- Fresno
- Department:
- Biology
- Creator:
- Sarvabhowman, Preethi
- Description:
- In the present study, we studied the growth characteristics of two species of green algae; Dunliella primolecta and Botryococcus braunii, in fruit industry wastewater and also studied the COD removal from wastewater by these species. We found that both the species of algae could grow better in 25% (v/v) wastewater reaching the stationary phase when compared to other concentrations of wastewater. However, Dunaliella primolecta was found to be growing faster than Botryococcus braunii, reaching a concentration of 8x106 cells/mL in 15 days. Also, it was found to remove 63% of COD from fruit industry wastewater obtained from Wawona Frozen Foods, CA. We also reported the first successful Agrobacterium tumefaciens method of transformation for the green algae Dunaliella primolecta using the binary vector pCAMBIA 1301 containing the genes coding for GUS (B-Glucuronidase) and hpt (hygromycin phospho- transferase). The developed transformation protocol would pave a way for easy manipulation of Dunaliella primolecta for the production of biofuels and other secondary metabolites.
- Resource Type:
- Thesis
- Campus Tesim:
- Fresno
- Department:
- Biology
- Creator:
- Upton, Kelli Renee
- Description:
- The general stress response principally results in the release of cortisol, with the overall effect of mobilizing metabolic energy and redirecting it towards homeostatic maintenance. Consequently, an important factor altered by stress is food intake. In several teleost species, a decrease in food intake following stress has been observed, though the neuroendocrine mechanism controlling the reduction in food intake during stress has yet to be determined. These studies were designed to investigate the effect of an acute stress on food intake and brain expression of corticotropin-releasing hormone (CRH), neuropeptide Y (NPY), ghrelin and ghrelin�s receptor and whether these effects are mediated by cortisol. Therefore, metyrapone, a cortisol synthesis inhibitor, was administered via feed in three doses of 10, 25, and 50 mg/kg body weight for 1 wk prior to a 30 min crowding and handling stress. Following the stressor, fish were allowed to feed for 1 h. Stress reduced food intake, while elevating mRNA levels of CRH, an appetite suppressor. Additionally, metyrapone treatment dose-dependently blocked the stress-induced reduction in food intake. While NPY and ghrelin levels were unchanged, an increase in ghrelin receptor activity suggests a function for ghrelin in regulating overall metabolism in response to stress. The elevation of CRH mRNA levels was also reversed with metyrapone treatment, suggesting cortisol and CRH play a role in mediating reduction of food intake during stress in tilapia.
- Resource Type:
- Thesis
- Campus Tesim:
- Fresno
- Department:
- Biology
- Creator:
- Anderson, Kathleen Mary Kennedy
- Description:
- In this study, substrate and water agitation of the echinoid habitat are related to the entocommensal incidence. Host species examined at Eniwetok had higher densities of entocommensal ciliates in lagoon waters than in surf waters on the fringing reef (Berger, 1964b). Lower infaunation rates for irregular hosts have been related to the ingestion of substrate unsuitable as food for ciliates (Berger, 1963b). Echinoid distribution and habitat data for areas having taxonomically similar echinoids to those of American Samoa have been reported for the Indo—Pacific islands of Hawaii (Ebert, 1971) and the West Indies-Florida area of Key Largo, Florida (Kier and Grant, 1965).
- Resource Type:
- Thesis
- Identifier:
- ocm56986158
- Campus Tesim:
- Fresno
- Department:
- Biology
- Creator:
- Janzen, Whitney Jean
- Description:
- In response to a stressor, an animal�s physiology is altered in an attempt to maintain homeostasis. Cortisol, a corticosteroid hormone that binds to the glucocorticoid receptor (GR), has widespread actions which mediate the stress response. In an aquaculture setting, fish are exposed to many stressors, which may negatively impact their growth and metabolism. The objectives of my thesis were to investigate the effect of cortisol on food intake, the hormonal regulators of appetite, glucose metabolism, and the growth axis. The tilapia (Oreochromis mossambicus) was used as the model because of its rapid growth and worldwide popularity as an aquaculture species. It was found that cortisol reduced food intake, which appears to be mediated by a reduction in the mRNA levels of the orexigenic hormones (NPY and ghrelin) in the telencephalon and diencephalon regions of the brain, as well as suppressed plasma and stomach ghrelin levels. mRNA levels for genes related to growth (IGF-I, GHR1, and GHR2) were elevated in the liver and muscle in response to cortisol. Total glucose levels were also elevated, as well as INSR mRNA in the liver. Treatment with the GR antagonist (RU-486) generally reversed the effects of cortisol, except in certain tissues, which may indicate the presence of multiple GR isoforms in tilapia. These results provide a mechanism for cortisol�s anorexigenic effects in tilapia.
- Resource Type:
- Thesis
- Campus Tesim:
- Fresno
- Department:
- Biology
- Creator:
- Fok, Katherine Sik-Ling
- Description:
- An earlier study on the effect of excess DL-methronine on Saccharomyces cerevisiae strain 3701B when cultured on a rich medium showed that there was an inhibition of cultural development during the first 6 to 12 hours. However, a sudden and sharp increase in cultural development occurred after the inhibition period. The purpose of the present study is to observe the effect on S_. cerevisiae when grown on defined and minimal media in the presence of varying concentrations of DL-methionine. The ∝-hydroxylmethyl group of serine is the dominant donor of methyl group in methionine synthesis, and the enzyme catalyzing the transfer of the ∝-hydroxylmethyl group in the formation of methionine is serine hydroxy-methylase. It is our present interest to note the effect of varying concentrations of DL-methionine on the production and activity of serine hydroxymethylase. It is also of Interest to note if varying concentrations of methionine would have any effect on the production of glutamic-oxalacetic aminotransferase, an enzyme which is not directly involved in methionine biosynthetic pathway.
- Resource Type:
- Thesis
- Identifier:
- ocm58533112
- Campus Tesim:
- Fresno
- Department:
- Biology
- Creator:
- Castro, Jamie
- Description:
- Early sexual maturation (precocity) of male salmonids is a serious issue in the modern conservation hatchery. Previous studies have demonstrated a ‘decision window’ of time for sexual maturation for Spring-run Chinook salmon beginning in the fall, during which the fish use biological and environmental cues to “decide” whether to mature for the following season. The months signifying the beginning and end of this fall decision window for California strains remains unclear. Therefore, an experiment was designed to elucidate the beginning and end of the decision window for California strains of male Spring-run Chinook salmon. A total of 628 juvenile males were randomly distributed among six tanks and fed a reduced ration diet during the predicted maturation decision window by adjusting duration and timing of diet reduction for each group. An additional 53 males were fed a high ration diet throughout the decision window. Individual weights and lengths were measured monthly. Precocity ranged from 32% to 10%, with the highest rate observed in the group fed a reduced ration between July- January and the lowest rate observed in the group fed a reduced ration between August-February. Additionally, condition factor (an estimation of adiposity), was observed to increase for males who would mature during the spawning season subsequent to the study period. Thus, it may be possible for hatcheries to implement feed reduction strategies to manage adiposity and precocity in broodstock.
- Resource Type:
- Thesis
- Campus Tesim:
- Fresno
- Department:
- Biology
- Creator:
- Whalen, William, Alexander
- Description:
- Traditional cell culture techniques grow cells in a two-dimensional (2D) format on compatible surfaces, but cells do not grow like this in vivo. A fast-emerging alternative is three-dimensional (3D) cell culture, which encourages cells to work together while suspended in a matrix rather than relying on adhesion to a treated surface. Most studies utilize a commercially available, industry standard recombinant basement membrane substitute--Matrigel ; however, this is proprietary and expensive. For these studies, my goal was to refine an alternative to Matrigel for use as a suspension media and surrogate extra-cellular matrix (ECM). My efforts focused on economical methylcellulose (a synthetic derivative of cellulose dissolved into basal growth media and called Methocel) in combination with rat-tail collagen (Type I). Optimized concentrations were evaluated towards the formation of spheroids among several cell lines including all three isogenic variants of a metastatic breast cancer cell line, MDA-MB-231, notoriously difficult to adapt to spheroid culture. I chose to use the metastatic breast cancer cell line MDA-MB-231 and two isogenic variants, MDA-MB-231Bo and MDA-MB-231Br, shown to regularly metastasize to either bone or brain respectively. This cell line series was used to evaluate the potential of this low-cost matrix to facilitate spheroid cultures; to determine expression changes in the canonical cell adhesion components Integrins (2, β1, and β4), as well as, E-Cadherins (ECAD) and N-Cadherins (NCAD); and to evaluate the functional significance of the spheroids to a relevant drug treatment. Here, by image analysis of spheroid metastatic progression and semi-quantitative RT-PCR analysis of metastatic cancer cells, we show the potential of this system in observing cancer cell migration and cellular behavior under more in vivo-like conditions, bridging the gap between basic two-dimensional cell culture and the animal model. Furthermore, through the use of this powerful model, we showed the efficacy of zoledronic acid to inhibit osteotropic breast cancer cell migration by up to ~14% post-72h treatment time. Lastly, zoledronic acid treated spheroids showed a continued improvement towards regaining more epithelial-like gene transcription profiles in genes associated with cells having undergone epithelial-mesenchyme transition. Together, these data add validity to our claim that metastatic studies using a surrogate extracellular matrix, such the one suggested in this study, continue to bridge the gap between typical two-dimensional cell culture and the animal model.
- Resource Type:
- Thesis
- Campus Tesim:
- Fresno
- Department:
- Biology
- Creator:
- Khorshidchehr, Darius Mehrnoosh
- Description:
- Fish execute a C start when they escape from a predator. Previous studies suggest that fish randomize their horizontal escape trajectories, but bias the response away from the stimulus. The fewstudies that looked at the vertical trajectory found that fish larvae respond to a horizontal stimulus with a downward escape trajectory. This study quantifies the escape trajectories of fish larvae in three dimensions. We use a vertical and a horizontal suction stimulus to explore the effect of stimulus direction on the escape trajectory. We found that zebrafish larvae (age 3 to 12 days post-fertilization) consistently responded to a horizontal stimulus with a downward trajectory. For the horizontal stimulus, out of 70 video recordings, 54 showed escape responses (77.1%). Fifty twoof those responses showed a downwards trajectory (96.3%). Thesedata suggestthat the same trend holds true when we use a vertical stimulus, simulating a benthic predator. The vertical stimulus, out of 131 video recordings, 131 showed escape responses (100%). From those responses, 129 showeda downwards trajectory (98.8%). Given the age range of the larvae, the downward trajectory cannot be explained by asymmetry of the body due to the presence of a yolk sac; the yolksac is absorbed usually at age 5 to 6 days. So the downward trajectory might be a hardwired response (zebrafish larvae are demersal) or indicate that fish have less control over their pitch than their yaw angle �the body movements during an escape response might be able to generate a wide range of yawing moments, but not pitching moments, leading to the observed bias in the trajectories.
- Resource Type:
- Thesis
- Campus Tesim:
- Fresno
- Department:
- Biology
- Creator:
- Arteaga, Erik Santigo
- Description:
- Klebsiella pneumoniae is a problematic gram-negative bacterium which commonly causes nosocomial infections such as pneumonia, urinary tract infections, burn wound infections, and bacteremia. K. pneumoniae is particularly virulent due to its ability to form biofilms within its host. Recent studies have revealed an upward trend of nosocomial infections caused by multidrug resistant (MDR) strains of K. pneumoniae. Most worrisome are extensively drug resistant strains (XDR), as they can withstand treatment with carbapenems, which are considered the most effective antibiotics in treating microbial infections caused by gram-negative organisms. RNA-sequencing of a biofilm of an MDR strain of K. pneumoniae (BAMC) treated with carbapenems for two hours demonstrated significant differential gene expression in treated biofilms compared to untreated controls. One gene of interest was the alternative sigma factor rpoS which controls the cells’ entry into stationary phase. In this study we attempted to identify the role of RpoS in antibiotic tolerance, virulence, and heat tolerance in K. pneumoniae. A rpoS knockout mutant was generated in the BAMC background. We found that the mutant was not defective in antibiotic or heat tolerance. We believe these responses may be modulated through another mechanism. Our rpoS knockout strain was found to be deficient in virulence in our infection model, Galleria mellonella. This research may provide potential drug targets for MDR or XDRorganisms.
- Resource Type:
- Thesis
- Campus Tesim:
- Fresno
- Department:
- Biology
- Creator:
- Hill, Alya Juwariah
- Description:
- This was the first survey in the central and southern San Joaquin Valley to identify the hard tick species present in this region. Hard tick distribution and diversity were evaluated in Fresno County and adjacent areas by (i) collection of ticks at three different elevation habitat sites and from veterinary sources, and (ii) subsequent phylogenetic comparison using fragments of 16S rDNA. A total of 178 ticks of 4 species were identified: Dermacentor occidentalis (n = 65), D. variabilis (n = 31), Ixodes pacificus (n = 2), and Rhipicephalus sanguineus (n = 80). Each species was restricted to a single habitat, but with detectable genetic variability within each species. R. sanguineus were only collected from dogs, I. pacificus were only collected from Kreyenhagen Peak, D. occidentalis were only collected from Coalinga Mineral Springs, and D. variabilis were only collected from China Creek Park. Further research is suggested to increase numbers of sampled sites, and to evaluate presence of tick borne pathogens.
- Resource Type:
- Thesis
- Campus Tesim:
- Fresno
- Department:
- Biology
- Creator:
- Hwang, Daeun
- Description:
- Parkinson’s disease (PD) is the most common neurodegenerative movement disorder. Research has identified several factors that play an important role in PD, and one of the factors is protein called α-synuclein.Overexpression of A30P or A53T promotes the formation of toxic filamentous inclusions in neurons that mediate motor output, resulting in movement deficits. The present study involved using Drosophila melanogasterto examine the behavioral dysfunction associated with α-synuclein linked to PD. The specific aim of this study was to develop an obstacle avoidance behavioral assay to quantify motor control and movement planning deficits in flies. Flies were genetically altered to carry A30P or A53T protein in specific brain regions known to be associated with sensory integration and locomotor abilities in insectsand their behavior assessed at different ages. Our data suggest that Drosophila expressing α-synuclein exhibit significantly different locomotor responses in speed and distance of negotiating an obstacle, with the greatest deficitsin central complex mutants.Moreover, aged mutant flies had lower success rate in negotiating the obstacle than young flies. These findings suggest that flies expressing α-synuclein may have issues with coordinating and executing fine control of movement in the obstacle avoidance activity. Therefore, this study can provide new insight into our understanding of the potential effects of α-synuclein in PD.
- Resource Type:
- Thesis
- Campus Tesim:
- Fresno
- Department:
- Biology
- Creator:
- Meyer, Erik
- Description:
- This study investigated the potential effects of cholinesterase (ChE) inhibiting pesticides and thyroid hormone changes from blood mercury (Hg) concentrations in western pond turtles (Emys marmorata) occupying streams in two regions of California, USA. The southern region is suspected of having increased exposure to atmospheric deposition of pesticides originating from Central Valley agriculture compared to the northern region. Total ChE activity of turtles was significantly depressed by 31% (p = 0.005) in the southern region after accounting for additional sources of variation in ChE activity. Male turtles had significantly increased ChE activity compared to females (p = 0.054), but cloaca temperature, length, mass, handling time, body condition, and lymph presence were not significant predictors of turtle ChE activity. Conversely, turtles in the northern region were suspected of having increased Hg exposure from historic gold mines compared to the southern region. Erythrocyte Total Hg (THg) concentrations in turtles ranged from 0.179 to 3.197 mg kg-1, with the highest mean concentrations found in the northern region and the lowest in the southern region. A positive correlation between mean turtle erythrocyte THg concentrations and the number of historic gold mines within a study watershed may exist (p = 0.057). Plasma triiodothyronine and thyroxine (T4) concentrations were not significantly influenced by THg concentrations, although T4 was significantly related to capture time of day (p = 0.042) and body mass (p = 0.031), and males had increased plasma T4 compared to females (p = 0.001).
- Resource Type:
- Thesis
- Campus Tesim:
- Fresno
- Department:
- Biology
- Creator:
- Brown, Matthew David
- Description:
- Suction feeding is an important feeding mode in aquatic organisms and is used across a considerable size range, from tadpoles to whales. Our current understanding is based on how adult fish feed and suggests that suction feeding is not effective for organisms just a few millimeters in size. All suction feeders have to overcome the inertial and viscous forces exerted by the water when sucking in water plus prey, yet only the inertial forces contribute to prey capture, while viscous forces contribute just to the cost and reduce the effectiveness of prey capture. Large predators do not need to complete their suction strikes as quickly as small predators because the contribution of viscous forces is low. We therefore predicted that (1) small suction feeders complete feeding events more quickly than large suction feeders, and that (2) smaller suction feeders approach the lower size limit and hence cannot generate the same high flow speeds as larger suction feeders. We focused on two species of the aquatic carnivorous plant bladderwort, Utriculariagibba and U. vulgaris, that capture zooplankton in traps that are just 1-5 mm long. We quantified the movements of the bladders during feeding strikes and their peak flow speeds. We found that bladderwort feeding strikes are much briefer than those of adult fish, and that the smaller bladderwort species, U. gibba, generates slower flows than the larger U. vulgaris, suggesting that U. gibba feed near the lower size limit.
- Resource Type:
- Thesis
- Campus Tesim:
- Fresno
- Department:
- Biology
- Creator:
- Olson, Eugene A
- Description:
- This study deals with the vertical conation in forage "behavior of the "bird population In a pure coniferous forest association. In addition, it is an attempt to investigate the concept that groups of organisms function in a protoplasmic manner and that life on this earth is a system of conscious or unconscious cooperation, with each organism being an apex of a functional hierarchy and also a foundation stone of many others; each organism is dependent on some other organisms but is also independent of a multitude of others. Food chains and webs are the sustaining factors for the ever-present but fluctuating pyramid of numbers. This study near Nordern, California, beginning July fourth and ending August first, 1951, shows that birds In a forest association will forage in a stratified system in aooordar.se with the height of vegetation levels and where their favorite or most abundant food is located. This paper will Include stratal foraging behavior, an index census of numbers of individuals per species and an annotated checklist of the birds encountered during the study.
- Resource Type:
- Thesis
- Identifier:
- ocm61409632
- Campus Tesim:
- Fresno
- Department:
- Biology
- Creator:
- Rosenthal, Elianna
- Description:
- The San Joaquin River (SJR) in California’s Central Valley represents the historical southern-most range of Chinook salmon (Oncorhynchus tshawytscha). In 2006, the San Joaquin River Restoration Program (SJRRP) was created to mitigate the negative effects of the Friant Dam which has caused degradation of extended portions of the SJR. The artificially changing hydrology of the SJR affects the thermal dynamics of restoration reaches which plays a significant role in growth and metabolism of juvenile Chinook salmon (JCS). Mass standardized growth rates () of SJR JCS cohorts (n=4) were compared to other wild (n=4) and hatchery (n=10) JCS populations. The estimated of wild SJR are high compared to other wild populations and are comparable to hatchery populations, despite living in what is regarded as “poor conditions.” The temperature optima and critical level for the SJR set by the SJRRP are based on EPA Region 10 (Pacific Northwest). Using a new JCS bioenergetics model with updated parameters and accurate recorded temperatures, bioenergetic model simulations were run to examine population-specific temperature regulation of manifested and potential growth. The results suggest that SJR JCS can continue their high growth rates with ample prey. My results suggest the importance of population-specific growth rate parameters and call into question the practice of applying bioenergetic and metabolic estimates from one population to other populations of Chinook. These data can help inform both water management and salmon conservation, especially in California where river water temperatures are highly regulated by water agencies and conflicting water demands and uses.
- Resource Type:
- Thesis
- Campus Tesim:
- Fresno
- Department:
- Biology
- Creator:
- Krishnamurthy, Sanjana
- Description:
- This study investigated the impact of different instructional strategies on students’ understanding about the cell cycle in a general education biology course. Although several studies have documented gains in students’ cell cycle understanding after instruction, these studies generally use only one instructional method, often without a comparison group. The goal of this study was to learn more about students’ misconceptions about the cell cycle and how those ideas change after three different evidence-based learning experiences in undergraduate general education. Undergraduate students in six laboratory sections (n = 24; N = 144) in a large public institution in the western United States were surveyed pre- and post-instruction using a 14-item valid and reliable survey of cell cycle knowledge. Cronbach’s alpha for the standard scoring convention was 0.264 and for the alternate scoring convention was 0.360, documenting serious problems with inconsistent validity and reliability of the survey. Operating as though the findings are at least a proxy for actual cell cycle knowledge, score comparisons by groups of interest were explored, including pre- and post-instruction differences among demographic groups of interest and three instructional settings: a bead modeling activity, a role-playing game, and 5E instructional strategy. No significant differences were found across groups of interest or by strategy, but some significant item-level differences were found. Implications and discussion of these shifts is noted in lieu of the literature.
- Resource Type:
- Thesis
- Campus Tesim:
- Fresno
- Department:
- Biology
- Creator:
- Nichols, Robert D.
- Description:
- The objective of this study was to determine the distribution and interrelationships of the fishes of the San Joaquin River drainage of the Sierra Nevada foothills, which have not been adequately checked since 1898 and 1899 (Rutter, 1908). A complete distributional list of Central California fresh water species was compiled some forty years ago (Evermann, 1931) with subsequent distributional studies limited to one or a few species. Two major f a c t or have warranted this distributional study. (1) extensive development of the area since the turn of the century, which includes intensive agriculture, mining, industry, large population centers; and (2) widespread introduction of numerous species from the eastern United States, which have had considerable effects on the distribution of native fish fauna. These man oriented factors have drastically changed the distribution and quality of fresh water habitats. At this time four rather distinct associations of native and exotic species exist in the foothill streams of this drainage (Moyle and Nichols, in press). The distribution of these associations and the distributions of the individual species are charted.
- Resource Type:
- Thesis
- Identifier:
- ocm61387402
- Campus Tesim:
- Fresno
- Department:
- Biology
- Creator:
- Thompson, Bruce E.
- Description:
- The oceans, once believed infinitely vast and stable, have recently been subjected to considerable alteration from other than natural sources. The time has come when we must try to control these alterations and attempt to maintain the oceans as a natural system. To accomplish this we must know precisely how this intricate system operates, both physically and biologically. The energy transformations of the photosynthetic plankton lie at the beginning of this system. Logically then, priority should be given to investigations directed towards a better understanding of these basic processes. We must know the physical and biological factors involved, which factors limit the system, the composition and distribution of the plankton, and biology of these constituents. By knowing these factors we can understand the beginning of the marine ecosystem.
- Resource Type:
- Thesis
- Identifier:
- ocm62894063
- Campus Tesim:
- Fresno
- Department:
- Biology
- Creator:
- Esani, Saika
- Description:
- Persister cells are a small percentage of the bacterial population (0.01-10%) that survive antibiotic therapy along with other stressors. They do this without undergoing any genetic change, only phenotypic variation. The exact mechanisms of persister cell formation are still not completely understood. We are in the process of identifying genes important for persister cell formation in a highly virulent respiratory pathogen, Pseudomonas aeruginosa. This organism is a major health concern, especially since antibiotic resistance is on the rise. We found high levels of differentially gene expression in persister cells through RNA sequencing. Interestingly, we found more genes were actually upregulated compared to downregulated. These results indicate that previously held ideas about persister cell dormancy are debatable. We quantified persister cell formation in selected mutants by directly evaluating the number of colony forming units (CFUs). Selected hits included pyocin synthesis genes, where mutants failed to form any persister cells. We characterized the role of two genes, PA3819 and gshA, through assays of physiological and biochemical functions including pyocyanin production, biofilm formation, and motility of both mutants in order to characterize the role of these genes within the cell. The knowledge derived from these studies will help identify better targets for treatment of P. aeruginosa acute infections, chronic infections, and post-treatment relapses.
- Resource Type:
- Thesis
- Campus Tesim:
- Fresno
- Department:
- Biology
- Creator:
- Hidalgo, Fatima
- Description:
- Suction feeding is a common feeding mode in macroscopic aquatic organisms and the dominant feeding mode in fish. In contrast, microscopic aquatic organisms do not use suction feeding. In fact, the smallest known suction feeders are fish larvae and bladderwort, a genus of carnivorous plants that catches zooplankton in underwater traps, both of which have gapes around 200 microns in diameter. Experimental and theoretical studies of suction feeding have shown that the ability to generate a steep spatial pressure gradient correlates strongly with capture success. Those studies also show that suction feeding is essentially an inertial process and therefore will be effective only if viscous fluid forces can be neglected, which is as long as the gape is large enough and the suction flow (i.e. the negative pressure gradient near the mouth) fast enough to minimize the relative effects of friction. Our current understanding of the hydrodynamics of suction feeding suggests that suction feeding is not effective in small organisms. In fact, both mathematical models of suction feeding, and experimental observations of larval fish suggest that their gape of 200 microns is near the lower size limit of suction feeding and that their suction flows generated by a 0.2 kPa pressure differential are too weak to ensure prey capture. In this project, we explored the lower size limit of suction feeding by characterizing the suction flows of bladderwort and salamanders and using the data collected to develop a robotic model of a suction feeder.
- Resource Type:
- Thesis
- Campus Tesim:
- Fresno
- Department:
- Biology
- Creator:
- Tanadjaja, Elsie Dekawati
- Description:
- Rhodoliths are free-living coralline algae that produce carbonate sediments in shallow water marine systems worldwide. Rhodalgal sediments, which result from rhodolith breakage and chemical weathering, mix together with living rhodoliths and form shallow water habitats known as rhodolith beds, support a diverse assemblage of organisms. Rhodoliths and sediment cores collected from the El Requeso?n rhodolith bed in Bahi?a Concepcio?n, Me?xico were used to study the basic mechanical and chemical processes involved in rhodalgal sediment production and basic framework of a rhodolith bed. Results showed four major groups of rhodalgal sediments produced from rhodolith breakdown: "cores," "branches," "crumbs," and �dust� that ranges in size from pebbles, sands, to silts. Dissolution of rhodoliths was evident at seawater below pH 7.5 and at 30% dissolution, core breakdown was accelerated and smaller branches were produced. The general vertical trend of coarse-fine-coarse sedimentary texture indicates the temporal dynamics of a rhodolith bed, suggesting movement in south-north-south direction or expansion-shrinkage-expansion of the active part of the bed from past to present. The effect of 30% dissolution seen in the experiment suggests that dissolution occurring in future high CO2 ocean conditions would cause structural changes to shift towards more compacted framework with smaller interstitial spaces, hence changing the habitat quality of the bed.
- Resource Type:
- Thesis
- Campus Tesim:
- Fresno
- Department:
- Biology
- Creator:
- Shipman, Charles
- Description:
- It is the purpose of this paper to present and analyze the results obtained in neutralization studies of four bacteriophages of Bacillus pumilus. Suppositions as to the interrelations among the four bacterial viruses are presented.
- Resource Type:
- Thesis
- Identifier:
- ocm62263218
- Campus Tesim:
- Fresno
- Department:
- Biology
- Creator:
- Braganza, Conrad Fredrick
- Description:
- Retired farmland in the western San Joaquin Valley (SJV) of California is frequently colonized by invasive plants that may limit the establishment of native flora. Limited ecophysiological data on native and invasive SJV plant species constrains science-based restoration of native flora. This greenhouse evaluation involved a comparison of photosynthetic rates, in vivo nitrate reductase activity (NRA), and biomass accumulation of two invasive annuals and three native annual species. At 35d and 75d, 15 individuals were harvested to determine total biomass. Photosynthesis was measured using a Li-Cor Li-6400 and in vivo NRA was measured in roots and leaves. At harvest 1, the photosynthetic rate of invasives (15.5�0.56 _moles CO2�m-2 �s-1) was greater (p<0.05) than natives (10.6�0.43 _moles CO2�m-2 �s-1). Natives significantly exceeded (p<0.05) the water use efficiency of invasives by 22% and 31% at harvest 1 and 2, respectively. In all species, leaf NRA exceeded root NRA (p<0.001; p<0.05). The total biomass of invasives significantly exceeded (p<0.05) that of natives at harvest 1 and 2 (0.25�0.003 g and 0.46�0.002 g, respectively). By harvest 2, the relative growth rate (RGR) of natives (0.069�0.03 g�g-1�d-1) exceeded invasives (0.043�0.07 g�g- 1�d-1, p<0.05). Greater early season photosynthesis, biomass and RGR of invasives likely aid in out competing natives and may contribute to low rates of native species establishment on retired farmland.
- Resource Type:
- Thesis
- Campus Tesim:
- Fresno
- Department:
- Biology
- Creator:
- Ogden, Gary L
- Description:
- The purpose of this paper is to describe some of the factors which influence seed germination and seedling survival or the California Buckeye and to relate these factors to the distribution pattern. Benseler (1969) found that-most seed and seedling mortality was caused by desiccation and fungus damage. Evidence from the present study indicates that other factors may be at least as important to both seedling survival and tree distribution.
- Resource Type:
- Thesis
- Identifier:
- ocm61411177
- Campus Tesim:
- Fresno
- Department:
- Biology
- Creator:
- Lindegren, James E
- Description:
- Howardula okumural la the only currently recognized sphaerulariid from nitidulid beetles. Its host range Is United to Carpophilus mutilatus. Locality records for this nematode include Alabama, Mississippi, Georgia, Texas, Florida and Mexico, g. okumural females say be found in the haemocoel of all larval instars of the host. The fannies enlarge in the host pupae and expel larvae in the newly emerged adults. Resultant fully developed third stage nematodes penetrate the midgut of deed nod dying adult beetles. They then become quiescent end grouped in the rectum or exit through the anus end locate as dauer larvae under the elytra of the host. They then molt twice end mature within 24 hours, mate mad remain viable up to 16 days in a 0.65 percent Ringer’s saline solution. Compared to control populations thlrty-day old parasitized beetle adults produced one fifth the number of larvae, end the females contained one fifteenth the number of mature ova.
- Resource Type:
- Thesis
- Identifier:
- ocm60756049
- Campus Tesim:
- Fresno
- Department:
- Biology
- Creator:
- Feaver, Paul E
- Description:
- Amphibians "that: breed in temporary bodies of water are confronted with problems of pool availability and larval mortality due to dessication of the breeding pools. Due to the low normal rainfall during the spring of the year, the mortality to the larvae is great because many pools dry before the larvae are able to complete development. In the area studied there are three species of amphibians which use vernal, pools and other temporary bodies of water for breeding. These are the California Tigar Salamander, Ambystoma tigrinum californiense Gray, the Pacific Tree Frog, Hyla regilla Baird and Girard, and the Western Spadefoot Toad, Scaphiopus hammondi hammondi Baird. The California Tiger Salamander (Ambystoma) and the Western Spadefoot Toad (Scaphiopus) breed only in temporary bodies of water, usually vernal pools. The Pacific Tree Frog (Hyla) breeds both in vernal pools and in permanent bodies of water. The purpose of this study was to try to determine the factors influencing breeding pool selection by Amby stoma, Hyla and Scaphiopus and to observe the development and survival of their larvae in pools selected for breeding. The factors examined in this study were pool size, pool location, the amount of vegetation and zooplankton in the pools, and the effect of mixed larval populations in the pools. The particular area of study was selected because of the number and variety of vernal pools and because all three species of amphibians breed in the pools in the area. The study was carried out from March 14 to May 7, 1.970, although information on the migration and breeding of the amphibians was noted before the initiation of the study.
- Resource Type:
- Thesis
- Identifier:
- ocm58533298
- Campus Tesim:
- Fresno
- Department:
- Biology
- Creator:
- Marquez, Ernest D
- Description:
- An increased interest has been shown in the exotoxins of the bacterium Staphylococcus aureus and their relationship to disease since 1872 when Klebs, speaking of staphylococcal infections, suggested that these organisms produce disease by means of diffusible substances which he termed "sepsins." Early investigators were able to demonstrate that in addition to dermonecrotic and lethal effects, the staphylococcal toxin had a leucocidic effect on rabbit white blood cells and lysed rabbit erythrocytes. Although this knowledge was available, it was largely neglected until the Bundaberg disaster in 1928. In Bundaberg, Australia, 12 children died after being inoculated with a diphtheria toxin-antitoxin mixture which had become contaminated with S. aureus. The lethal effect was attributed to the staphylococcal toxin. Burnet's (10,11) subsequent investigations of the disaster disclosed that the toxin could be produced in significant quantities for laboratory investigations and that the toxin was a true exotoxin capable of killing rabbits on intravenous injection. These findings prompted increased interest in the investigation of staphylococcal toxins (12, 15, 30, 50). It is now known that a crude staphylococcal toxin preparation is composed of various substances. These include coagulase, staphylokinase, and hyaluronidase, the so-called "spreading factors", Panton--Valentine leucocidin, a distinct enterotoxin, and four hemolysins (17, 63). The latter have been termed alpha, beta, gamma, and delta hemolysins (25, 57, 64, 72). Of these, the alpha hemolysin has received the most attention and has been so frequently associated with the lethal and necrotizing factors that the terms alpha hemolysin and alpha toxin have been used interchangeably. Supernatants from staphylococcal cultures are hemolytic in vitro, lethal for small laboratory animals, produce necrotizing lesions following injection into the skin of animals, cause smooth muscle to undergo contractions and loss of function, and bring about cortical necrosis of the kidneys when injected intravenously into experimental animals (1, 17, 30, 65, 67, 68). Until recently, it had been difficult to ascribe a specific function to alpha toxin because of the unavailability of purified material. However, as more gentle and effective methods of protein separation have become available, attempts at alpha toxin purification and characterization have met with various degrees of success. Several groups of investigators claim to have prepared purified alpha toxin which was homogeneous, producing a single precipitin line on gel diffusion and immunoelectrophoresis (9, 14, 26, 31, 37, 39). With these preparations and with many others known to be impure, a variety of tests have been conducted to determine the activity of alpha toxin. Based on the conclusions reached by various investigators (9, 26, 31, 36) there seems to be some agreement that the lethal, dermonecrotic and hemolytic effect of supernatants from staphylococcal cultures are due to one and the same substance, the alpha toxin fraction (5). Other effects attributed to alpha toxin are a lytic effect on rabbit and human leukocytes (8, 26, 30), necrosis of human skin (26), damage to human platelets (7, 40, 59), damage to rabbit kidney, Ehrlich ascites, human epidermoid (KB), and monkey kidney cells in tissue culture (3, 4, 33), damage to pleuropneumonia-like PPLO) organisms (6), and damage to rabbit liver lysoscmes (8). In this investigation, sane localization of a lethal dose of alpha toxin in the heart and lungs of a mouse after intravenous injection was demonstrated by means of a fluorescent antibody technique. In addition, a possible direct action of the toxin on heart tissue was suggested by the observation that serum levels of alpha hydroxybutyric dehydrogenase and glutamic oxalacetic transaminase rose immediately after inoculation of the toxin.
- Resource Type:
- Thesis
- Identifier:
- ocm61117251
- Campus Tesim:
- Fresno
- Department:
- Biology
- Creator:
- Hansen, Judith E.
- Description:
- The present study- concerned the quantitative and qualitative comparison of two intertidal benthic algal floras. Data were collected from the experimental area, Ano Nuevo Point, and Pigeon Point the control area, both in San Mateo County California (Figure 1). Ano Nuevo Point is located 6^4- km south of San Francisco, California and .5 km north-east of Ano Nuevo Island. The substrate of the intertidal sampling areas was composed of Miocene cherty shale slabs, Intermixed with mudstone (Brabb, 1970). At a -1.2 ft tide, 250 m of intertidal area were exposed as measured from + 3.4 ft (in relation to mean lower low water, 0.0 ft). The point is partially protected from direct surf action by Ano Nuevo Island. The control site for the study was located approximately 300 m south of the lighthouse at Pigeon Point and 6.5 km north of Ano Nuevo Point. The substrate was composed of Cretaceous siltstone and conglomerate (Touring, 1959)° The composition of this substrate is quite similar to that at Ano Nuevo Point, but differs considerably in age. At a -1.2 ft tide, A-7 m of intertidal area were exposed, as measured from +3.9 ft. The study area was protected from direct wave shock by a 30 a by 15 m rock outcropping on the northern boundary of the sampling area and by Pigeon Point itself. The lack of pinniped hauling-out grounds in the vicinity of Pigeon Point was the only substantial difference between the environments of the experimental and control study sites.
- Resource Type:
- Thesis
- Identifier:
- ocm60247722
- Campus Tesim:
- Fresno
- Department:
- Biology
- Creator:
- Duris, Kathryn Ann
- Description:
- Considerable evidence links cumulative and sustained exposure to estrogens to breast tumor proliferation. Chemicals with estrogenic activity can bind to the estrogen receptor (ER) to affect downstream signaling of estrogen-responsive genes. Organochlorines (OC) are a class of chemical pesticides that can act as xenoestrogens to disrupt normal endocrine function. Methoxychlor and Toxaphene are two OC pesticides that have been widely used in California. However, the complete molecular mechanisms that connect OC pesticide exposure and breast cancer are still unclear. Experiments show that some members of the orphan nuclear receptor Estrogen Related Receptor (ERR) family interact with the OC pesticides and hypoxia inducible factors to modulate mitochondrial stress response. Mitochondrial DNA transcription is altered by estrogenic and stress signals. The mTOR pathway integrates different cellular stress signals to regulate glucose metabolism, insulin signaling, apoptosis, and cellular detoxification, all processes controlled by the mitochondria. This project investigates how organochlorine pesticides may increase intracellular oxidative damage that changes mitochondrial energy use to favor a cancerous phenotype, and do those changes differ based on Estrogen Receptor (ER) status. To explore this problem I use ER+ and ER- cell lines to evaluate the expression of proteins, and their mRNA, involved in pesticide binding (ERR?, ERR?, and ERR?), oxidative stress (PGC-1?, HIF-1?, -1?, -2?), and mitochondrial function (mTOR, SIRT1, FOXO1).
- Resource Type:
- Thesis
- Campus Tesim:
- Fresno
- Department:
- Biology
- Creator:
- Sciutto, James R
- Description:
- There exists among genetic forms the simplest self-replicating biological entity; namely, the "viruses." To define the term "virus" is not easy, for viruses cannot be defined by common-sense criteria the way animals and plants can. The term "virus" was first used by the ancient Roman physicians to denote a poison of animal origin. The diseases caused by such poisons were called "virulent." During the late nineteenth century Ivanowsky found that these invisible infectious agents were much smaller than bacteria. Because they retained their infectivity after passage through a filter able to retard the passage of all then-known types of bacteria, these submicroscopic agents were termed "filterable viruses." The early twentieth century brought with it the discovery that viruses were subcellular entities capable of entering living cells and of reproducing only in such cells. The viruses were thus referred to as "obligate intracellular parasites" whose specific action was at the level of the gene.
- Resource Type:
- Thesis
- Identifier:
- ocm62589640
- Campus Tesim:
- Fresno
- Department:
- Biology
- Creator:
- Holland, V. L.
- Description:
- The purpose of the present study is to gain some insight into the complex of factors that create the canopy effect with emphasis on the microenvironment that is associated with the vegetative differences. Data recorded weekly included the measurement of plant growth, precipitation, air temperature, soil moisture, and soil temperature. Other studies involved pH, bulk density, permanent wilting percentage, moisture equivalent, field capacity, organic content of the soil and. plant distribution. The determination of all factors involved was not possible in the two growing seasons studied, but accrued data suggests certain ecological relationships. The investigation was undertaken at the San Joaquin Experimental Range (SJER) near O'Neals, California, 25 miles north of Fresno. The SJER is situated on the east side of the San Joaquin Valley in the Sierra Nevada foothills. The natural vegetation is typical of the foothill woodland community (as recognized by Munz, 19&3) consisting of trees 15-70 feet tall in an open woodland with scattered brush and grassland between the trees.
- Resource Type:
- Thesis
- Identifier:
- ocm58723865
- Campus Tesim:
- Fresno
- Department:
- Biology
- Creator:
- Delmanowski, Robert
- Description:
- Petrolisthes cinctipes and P. manimaculis are two closely related species of anomurans that live in the upper intertidal zone along the Central California coast. Morphometric measurements were collected to gain insight on the reproductive cycles of these species. Ovary weights of P. cinctipes increased from July (0.2 ? 0.1 ?g) to September (18.0 ? 6.0 ?g), remained similar through January (19.0 ? 7.0 ?g), and then decreased in February (5.6 ? 3.0 ?g). Vitellin (Vn), an egg yolk protein, is metabolized from a larger hemolymph protein, vitellogenin (Vg). The Vns of both species were isolated and characterized. Using SDS-PAGE it was determined that the Vn of the conspecifics, P. cinctipes and P. manimaculis, consist of three major subunits that have a MW of 93 ? 2 kDa, 82 ? 2 kDa, and 65.7 ? 1.4 kDa. Two minor bands were also detected at 111 ? 2.3 kDa and 40 ? 1.3 kDa. Using HPLC, the native molecular mass of P. cinctipes vitellin was found to be 301 ? 14 kDa with a small doublet. The native molecular mass for P. manimaculis Vn is 324 ? 11 kDa with a more pronounced doublet of 160 ? 13 kDa. A Western blot was used to test the reactivity of the Petrolisthes Vn with various antibodies. It was revealed that two of the major Petrolisthes Vn subunits, 93 ? 2 kDa and 65.7 ? 1.4 kDa, successfully bound with Homarus anti-Vn antibodies. An ELISA was developed that can measure Vn and Vg in the hemolymph of both Petrolisthes species, with an effective range from 9-3000 ng. There was no difference in mean Vg level from September (240 ? 100 ?g/mL) through January (310 ? 50 ?g/mL), with a total mean Vg concentration of 284 ? 32 ug/mL.
- Resource Type:
- Thesis
- Identifier:
- .b66450883
- Campus Tesim:
- Fresno
- Department:
- Biology
- Creator:
- Tucker, Vanessa Renae
- Description:
- The goal of this study was to evaluate the population dynamics of small nocturnal mammals and the occurrence of medium to large mammals at Naval Air Station Lemoore in Lemoore, CA and a proposed conservation easement along the Kings River nearby. To assess small mammal activity, trapping grids were placed at three sites from June 2011 to May 2012, and mark-recapture methods were used to estimate populations. Baited camera traps were placed in those sites and at two additional sites, and digital images were used to assess medium to large mammal occurrence. Deer mice (Peromyscus maniculatus) were the most common small mammals captured. Western harvest mice (Reithrodontomys megalotis) and California voles (Microtus californicus) were also captured, but in numbers too small to make population estimates. Populations of deer mice were abundant at the beginning of the study, most likely due to the season and the previous year�s higher than average rainfall. They also experienced a significant decline during the colder months (Oct-Jan), which could be explained by the high metabolic cost of maintaining their core body temperatures. The camera traps were largely unproductive and captured a total of two target species (coyotes [Canis latrans] and red foxes [Vulpes vulpes]) in 1,665 h of trapping. It is recommended that further studies be done to assess the many complex conservation and management issues that still remain unevaluated.
- Resource Type:
- Thesis
- Campus Tesim:
- Fresno
- Department:
- Biology
- Creator:
- Velázquez, Claudia Cristina S
- Description:
- The aim of this study was to examine the swimming locomotion of the green shore crab Carcinus maenas larvae (stage I zoeae), to investigate the role and mechanics of their swimming appendages. High speed video recordings of swimming and sinking zoeae revealed the kinematics of the whole zoea and its appendages. Analyses of these video recordings for swimming locomotion were performed using MATLAB software and ImageJ. From the body, maxilliped, and natatory setae kinematics and the zoea swimming gait, we found that swimming speed measurements were threefold higher than previously reported in green crab zoeae, and maximum and minimum maxilliped angles were greater than previously observed. We also quantified the flow generated by swimming zoeae using Particle Image Velocimetry (PIV). Analysis of recordings for flow fields was performed using the PIVlab-Digital PIV Tool for MATLAB. We obtained flow velocity and vorticity fields generated during free swimming and tethered zoeae. To our knowledge, this study is the first to report sinking speeds for green crab larvae, maxilliped and natatory setae speeds, and flow fields during routine free swimming and tethered escape responses.
- Resource Type:
- Thesis
- Campus Tesim:
- Fresno
- Department:
- Biology
- Creator:
- Ingles, Elizabeth
- Description:
- This thesis is the result of a study to determine the importance of geographic and climatic features in the distribution of the mammals of Middle America. Middle America is here defined as Mexico and Central America including the islands that belong to the countries studied. All the Recent mammals with the exception of the order Chiroptera are included in the study. The Chiroptera, or bats, are excluded because, since they alone of all the mammals can fly, geographic and climatic features are not such important ecological barriers to their distribution. Scientific names used in this study are based on Miller and Kellogg (1955). With a few exceptions specific rather than subspecific names are used.
- Resource Type:
- Thesis
- Identifier:
- ocm60405312
- Campus Tesim:
- Fresno
- Department:
- Biology
- Creator:
- Salas, Hailey Kathleen
- Description:
- Intertidal organisms, like the porcelain crab, regularly experience thermal stress. Petrolisthes cinctipes inhabits the upper-mid intertidal zone and is often exposed to aerial stressors at low tide. Increased abiotic stressors may interfere with many aspects of this organisms’ physiology, including reproduction. Reproductive activity can be measured through the quantification of the yolk protein vitellogenin (Vg), found in hemolymph. ELISA for P. cinctipes allowed for quantification of Vg in hemolymph. Vg sampling of P. cinctipes revealed decreased reproduction around the summer solstice. Reproduction may be dependent on environmental variables such as temperature or day length. To examine this, P. cinctipes were collected monthly for one year. After a pre-treatment hemolymph draw, crabs underwent treatment to test effects of long day lengths and daily exposure to thermal stress. After two weeks of treatment, a second hemolymph sample was drawn. Hemolymph samples were analyzed for Vg levels using an ELISA. Crabs collected near the summer solstice sustained low levels of Vg after exposure to thermal stress. Long day thermal stress conditions caused Vg production to decline in crabs collected during the winter solstice. These data suggest that P. cinctipes relies on multiple environmental cues in regulating reproduction, and changes in environmental conditions could interfere with this physiological process.
- Resource Type:
- Thesis
- Campus Tesim:
- Fresno
- Department:
- Biology
- Creator:
- Spaulding, Taylor John
- Description:
- Salmon fisheries managers often use models to determine the growth of individuals and populations for a variety of management objectives. Most models of juvenile salmon growth during their freshwater residency only incorporate activity costs for drift foraging when making growth assessments and predictions. I propose that fish may need to include a searching foraging strategy to meet their energy needs under certain situations, such as when prey are scarce, difficult to find, or if low water velocities do not promote high drift delivery. To investigate this I tested how the growth derived from otoliths collected from a cohort of wild juvenile Chinook Salmon (Onchorhyncus tschawytscha) in the San Joaquin River compared to predictions of growth derived from the individual based model inSTREAM. Model predictions of search foraging events were confirmed by stable isotope analyses, which suggested that a significant portion of total consumed biomass was derived from oligochaetes. The model was then used to simulate a variety of discharge and prey production scenarios to investigate their effects on growth and survival. Results from these scenarios suggest that prey production has the most significant effect on growth and survival, while all discharge levels above Critical Low are beneficial for growth and survival.
- Resource Type:
- Thesis
- Campus Tesim:
- Fresno
- Department:
- Biology
- Creator:
- Bono, Lori Rachelle
- Description:
- Toxoplasma gondii is a ubiquitous zoonotic protozoan parasite, whose infective and environmentally resistant oocyst stages can be transported into fresh and marine waters via freshwater runoff, stormwater discharge and sewer systems. The ingestion of these oocysts, either through direct consumption or through the consumption of filter-feeding marine bivalves, can have a detrimental impact on humans and a variety of marine mammals including the threatened southern sea otter (Enhydra lutris nereis). Terrestrial vertebrates are also susceptible to T. gondii infection since this parasite has a facultative heteroxenous life cycle that potentially includes all terrestrial vertebrates. Ticks (Acari) are known to serve as vectors for organisms that are pathogenic to humans and other animals, and it is suspected that ticks may serve as vectors for T. gondii and could facilitate transmission to terrestrial vertebrate hosts. This study evaluated the prevalence of T.gondii in populations of Pacific coast hard ticks (Dermacentor spp. and Ixodes spp.) and investigated the distribution and abundance of tick species in coastal terrestrial habitats. All ticks (n = 110) within the greater Morro Bay area, California tested negative for T. gondii. A significant difference was found between the number of flagged ticks at different sites and in different seasons. This study was the first to use DNA based analysis to attempt to detect T. gondii in Pacific coast hard ticks.
- Resource Type:
- Thesis
- Campus Tesim:
- Fresno
- Department:
- Biology
- Creator:
- Jorgensen, Christopher
- Description:
- Anthropogenic activities have severely impacted much of the life on Earth. To protect and preserve our remaining natural areas, conservation biology has traditionally focused on the impacts of humans on natural systems. Recently, conservation biology has incorporated phylogenetic metrics to better understand the evolutionary value of imperiled species. All extinctions include the loss of some biological value, but extinctions of many closely related species result in a disproportionate loss of evolutionary history relative to the same number of extinction events among distantly related species. Mammals are one of the most well-studied groups in phylogenetics, making them ideal candidates for evaluating the loss of evolutionary history that accompanies extinction. I use data collected from a published phylogeny on California’s native terrestrial mammals to investigate the relationships between conservation status, as a proxy for extinction risk, and phylogeny. I examined the potential losses of phylogenetic diversity and disparity by calculating the change in Phylogenetic Diversity (PD) and Net Relatedness Index (NRI) when species with elevated extinction risks were pruned from the California mammalian tree of life. These analyses reveal that the potential loss in PD and NRI is equal to or even lower than expected from a random loss of the same predicted number of species. These results are consistent with global trends for mammals, but show how this global pattern is also present at some regional scales, which is not always the case in previous investigations.
- Resource Type:
- Thesis
- Campus Tesim:
- Fresno
- Department:
- Biology
- Creator:
- Melkonian, Tamar
- Description:
- Plant Parasitic Nematodes (PPNs) are a challenging problem in today's agriculture causing an annual loss of about 157 billion dollars (Li et al., 2015). Until recently, methyl bromide was the most used agent for controlling PPNs. However, methyl bromide is now not preferred because of its high toxicity (Li et al., 2015). This establishes a problem by losing a way to control these PPNs. In order to effectively kill these PPNs, Dr. Calderón-Urrea's laboratory used Caenorhabditis elegans (C. elegans) as a model organism and identified certain chalcones as effective nematicidal agents (Attar, 2011). Chalcones are organic chemical compounds found to be effective in killing the reference strain used in the ACU laboratory (PD4251) of C. elegans (Attar, 2011). For the purposes of this thesis the PD4251 strain, which contains the green fluorescence protein (GFP), is noted as the reference strain. Currently the lab has found three chalcones, 17, 25, and 30, that are effective in killing the reference strain, and although the mechanism behind the chalcones' mode of action is unknown, research in the lab suggests these three chalcones may target different biochemical pathways in the nematode.
- Resource Type:
- Thesis
- Campus Tesim:
- Fresno
- Department:
- Biology
- Creator:
- Clark, Jimmy D.
- Description:
- The life history of the many Blapstinus species, some of which are occasional pests of crops (Essig, 1926), is poorly known. Only one species, unidentified, has been reared (Blaisdell, 1926), and this on a media of "leafmould, powdered cow chip and soil." Blapstinus histricus Casey, a common species in Fresno, Fresno County, California, was found suitable for establishing rearing techniques and a life history pattern of itself and for Blapstinus until other species are studied.
- Resource Type:
- Thesis
- Identifier:
- ocm57664783
- Campus Tesim:
- Fresno
- Department:
- Biology
- Creator:
- Scheidt, Shaynon Travis
- Description:
- Previous experiments show that repetitive DNA makes up a large fraction of the pepper genome and contributes to its three-fold size difference with tomato. Further isolation and characterization of repetitive DNA is needed to achieve a better understanding of pepper�s genetic makeup and the evolution of the Solanaceae genome. A random genomic library was constructed from mechanically sheared pepper DNA. Twenty-seven clones, containing anywhere from 200 to 3000 bp, were sequenced and then were analyzed using BLAST against the DNA sequence databases GenBank, TIGR, and SGN. Sequencing results indicate that over half of the clones matched a repetitive class in at least one database and include a variety of retrotransposon, centromeric, telomeric, and ribosomal sequences. Internal repeat structure was analyzed using MEME and demonstrates that pepper nuclear DNA is made up of many short, interspersed repetitive elements as well as some longer repeats with known function. PCR results indicate that some of these repetitive sub-classes occur in other taxa within the Solanaceae family and beyond.
- Resource Type:
- Thesis
- Campus Tesim:
- Fresno
- Department:
- Biology