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Full-Text Articles in Life Sciences

Effects Of Sudangrass Cover Crop And Soil Solarization On Weed And Pathogen Management In Organic Strawberry Production, Timothy Jacobs Aug 2019

Effects Of Sudangrass Cover Crop And Soil Solarization On Weed And Pathogen Management In Organic Strawberry Production, Timothy Jacobs

Master's Theses and Project Reports

Field and lab experiments were conducted to determine the efficacy of sudangrass (Sorghum X drumondii (Nees ex Steud.) Millsp. & Chase) cover crop management techniques and soil solarization on important agricultural weeds and pathogens in organic strawberry production in Central California. Lab experiments assessed the time needed to kill weed seeds at temperatures typically achieved during soil solarization (40°C, 45°C, 50°C, 55°C, and 60°C) in California. Seeds tested included little mallow, redstem filaree, bristly oxtongue, annual sowthistle, common purslane, nettleleaf goosefoot, and redroot pigweed. Efficacy of simulated solarization temperatures differed between different species. Cool-season annuals annual ...


Short Term Shifts In Soil Nematode Food Feb Structure And Nutrient Cycling Following Sustainable Soil Management In A California Vineyard, Holly M. Deniston-Sheets Jul 2019

Short Term Shifts In Soil Nematode Food Feb Structure And Nutrient Cycling Following Sustainable Soil Management In A California Vineyard, Holly M. Deniston-Sheets

Master's Theses and Project Reports

Evaluating soil health using bioindicator organisms has been suggested as a method of analyzing the long-term sustainability of agricultural management practices. The main objective of this study was to determine the effects of vineyard management strategies on soil food web structure and function, using nematodes as bioindicators by calculating established nematode ecological indices. Three field trials were conducted in a commercial Pinot Noir vineyard in San Luis Obispo, California; the effects of (i) fertilizer type (organic and inorganic), (ii) weed management (herbicide and tillage), and (iii) cover crops (high or low water requirements) on nematode community structure, soil nutrient content ...


Development Of A Prolyl Endopeptidase Expression System In Lactobacillus Reuteri To Reduce The Clinical Manifestation Of Celiac Disease, Kara Lynn Jew Jul 2019

Development Of A Prolyl Endopeptidase Expression System In Lactobacillus Reuteri To Reduce The Clinical Manifestation Of Celiac Disease, Kara Lynn Jew

Master's Theses and Project Reports

Celiac Disease (CD) is an autoimmune disorder that emerges due to the ingestion of gluten, a protein found in a variety of common grains such as wheat, rye, and barley. Approximately 1 in 100 individuals in the US suffer from CD, making it the most commonly diagnosed gastrointestinal disorder (Ciclitira et. al., 2005). These proline-rich gluten peptides are resistant to proteolysis and accumulate in the duodenum of the small intestine. Once in the duodenum, these peptides illicit an autoimmune response resulting in villous atrophy. Current treatment for CD requires a rigorous adherence to a gluten-free diet. Nevertheless, gluten-containing grains are ...


Leaf Functional Traits As Predictors Of Drought Tolerance In Urban Trees, Sophia Huang Jun 2019

Leaf Functional Traits As Predictors Of Drought Tolerance In Urban Trees, Sophia Huang

Master's Theses and Project Reports

The services that urban trees provide to human society and the natural environment are widely recognized, but urban trees are in jeopardy due to climate change and urban stressors. With drought as a major threat in many areas, it is important for the future of urban forestry to select species composition based upon performance under water stress. Certain leaf functional traits can help horticulturalists more accurately predict water usage of urban trees. Comprehension through rigorous experimentation is lacking, partly due to the thousands of mostly exotic species. Previous studies suggest that species whose leaves have a denser arrangement of smaller ...


Study Of Paper Microbial Fuel Cells For Use In On-Site Wastewater Testing, William A. Tolmasoff, William A. Tolmasoff Jun 2019

Study Of Paper Microbial Fuel Cells For Use In On-Site Wastewater Testing, William A. Tolmasoff, William A. Tolmasoff

Master's Theses and Project Reports

This study demonstrated a technique for fabricating simple, low-cost Paper Microbial fuel cells (PMFC’s) in the model of a previous study to, for the first time, produce voltage from wastewater effluent. The PMFC’s were created by stacking and gluing the main components of an MFC together: reservoir layer; anode; cation exchange membrane (CEM); air cathode. A wax printer was used to create the hydrophobic borders of the PMFC’s on filter paper, and graphite paint was applied to the paper to create the anode. The CEM’s considered were filter paper, wax, and Nafion, with Nafion being the ...


Carbonate Chemistry Characterization In A Low-Inflow Estuary With Recent Seagrass Loss, Jolie Higgins Jun 2019

Carbonate Chemistry Characterization In A Low-Inflow Estuary With Recent Seagrass Loss, Jolie Higgins

Master's Theses and Project Reports

Estuaries are dynamic environments that are strongly affected by natural variability, as well as direct and indirect anthropogenic impacts. A better understanding of the drivers of carbon fluxes and biogeochemical variability in estuarine systems is needed, particularly with the increasing threat of ocean acidification. Morro Bay in Central California is a small nationally protected estuary, with seasonally low freshwater inputs. Since 2007, the bay has experienced a significant loss of native seagrass, Zostera marina, which is an important component of the marine ecosystem. Because seagrass photosynthesis decreases carbon dioxide and increases oxygen in the water column, the loss of seagrass ...


Effects Of Barotrauma On Four Species Of Pacific Rockfishes (Sebastes Spp.), Lesley Salter Jun 2019

Effects Of Barotrauma On Four Species Of Pacific Rockfishes (Sebastes Spp.), Lesley Salter

Master's Theses and Project Reports

Physoclistic fish, such as Pacific rockfishes (genus Sebastes), have closed swim bladders that help them regulate their buoyancy. When anglers catch these fish and reel them to the surface, gases within their swim bladder expand due to the decrease in pressure. This can cause their swim bladder to over inflate––a condition known as barotrauma. Overly buoyant fish experiencing barotrauma often struggle to swim back to dwelling depth if released at the ocean’s surface. These fish may experience high rates of mortality by thermal shock caused by the warmer surface temperatures, starvation, predation, or vision problems caused by barotrauma ...


The Effects Of Agricultural Waste-Based Compost Amendments In Organic Pest Management, Gregg T. Stephenson Jun 2019

The Effects Of Agricultural Waste-Based Compost Amendments In Organic Pest Management, Gregg T. Stephenson

Master's Theses and Project Reports

Soil-borne pests and pathogens, such as Verticillium dahliae, can devastate a wide range of annual and perennial crops. Current management options for organic production are limited and sustainable management of pathogens, weeds, and arthropods is important for staying profitable and reducing the use of harmful chemicals. Organic soil amendments play an important role in supplying some of the nutritional needs of vegetable crops and improving soil structure, while also contributing to pest control. The objective of this research was to determine the effects of grape and olive-based composts on soil pathogen load, arthropod communities, and weed biomass and diversity. Field ...


Strawberries And Gut Health In Postmenopausal Women, Morgan T. Macneill Jun 2019

Strawberries And Gut Health In Postmenopausal Women, Morgan T. Macneill

Master's Theses and Project Reports

The gut microbiota has been implicated in both health and disease. As such, diet is a significant determinant of gut health, whereby diet induced dysbiosis is associated with cardiometabolic risk. Interestingly, a higher proportion of Firmicutes and a lower proportion of Bacteroidetes are implicated in obesity. Strawberry polyphenols have been shown to reduce cardiovascular disease risk in addition to exhibiting prebiotic activity by increasing probiotic bacteria in the gut. Polyphenols have also been shown to reduce the ratio of Firmicutes to Bacteroidetes. Therefore, dietary modifications such as strawberry consumption may help improve health outcomes through the gut. The objective of ...


Evaluation Of Host Resistance And The Utilization Of Organic Amendments To Manage Macrophomina Crown Rot Of Strawberry In California, Jonathan W. Winslow Jun 2019

Evaluation Of Host Resistance And The Utilization Of Organic Amendments To Manage Macrophomina Crown Rot Of Strawberry In California, Jonathan W. Winslow

Master's Theses and Project Reports

The production of strawberries can be severely limited by soilborne plant pathogens, insects and weeds. Macrophomina phaseolina is a problematic soilborne fungal pathogen in California strawberry production inciting the disease Macrophomina crown rot. When established, the pathogen can cause extensive plant decline and mortality. Host resistance will be a critical tool for managing this disease and guiding breeding programs in the post methyl bromide era. Evaluation of host resistance in strawberry germplasm to M. phaseolina was evaluated through phenotypic assessments of disease incidence. A total of 90 strawberry cultivars and elite selections were included in a replicated field trial conducted ...


The Effect Of Alcohol And Bitterness Levels On Brewing Yeast Viability, Nichole Elizabeth Bryant Mar 2019

The Effect Of Alcohol And Bitterness Levels On Brewing Yeast Viability, Nichole Elizabeth Bryant

Master's Theses and Project Reports

Two of the most popular beer styles within the craft brewing industry are India Pale Ales (IPA’s) and those with high alcohol by volume (ABV). Production of these styles requires high gravity fermentation and high amounts of bittering hops in order to reach the required values for ABV and International Bitterness units (IBU) respectively. The aim of this study was to determine the impact of high gravity fermentation and high IBU levels on yeast viability and repitching cycles.

An initial experiment on high gravity fermentations was done in order to assess the effects this variable had alone. Successive five ...


Effectiveness Of Windrow Composting Methodology In Killing A Thermo-Tolerant Species Of Salmonella During Mortality Composting, Spencer Gabriel Myers Feb 2019

Effectiveness Of Windrow Composting Methodology In Killing A Thermo-Tolerant Species Of Salmonella During Mortality Composting, Spencer Gabriel Myers

Master's Theses and Project Reports

In a large agricultural operation, such as the one at Cal Poly San Luis Obispo, disposal of deceased animals is an immense issue. The cost of transporting and rendering every dead animal is inhibitory to the general function of the agricultural operations and their thin budget. Therefore, we propose that composting mortalities could be an economical alternative. Composting is a recognized method for taking animal waste products along with carbon waste and turning it into a pathogen-free, nutrient-rich topsoil. Carcass composting is in fact performed in other countries and states to varying degrees of success. However, the California EPA limits ...


California Livestock Owners: An Assessment Of Familiarity With New Antimicrobial Rules And Access To Educational Outreach, Philip Theodor Paulson Jan 2019

California Livestock Owners: An Assessment Of Familiarity With New Antimicrobial Rules And Access To Educational Outreach, Philip Theodor Paulson

Master's Theses and Project Reports

The purpose of this research is to support the California Department of Food & Agriculture (CDFA) with education and outreach about recent changes regarding antimicrobial use in livestock, and to enhance their emergency communications network. This was done by characterizing a population of small-scale livestock owners underserved with regards to educational outreach about animal health issues, such as antimicrobial use rules. The project also seeks to enhance public understanding of the importance of responsible antimicrobial use in animal and human health.

To accomplish this, the study used a survey administered in person at local farm supply stores and online to investigate ...