Physical Sciences and Mathematics Commons^™

Wildfires Disturb The Natural Skin Microbiota Of Terrestrial Salamanders, Lubna Mulla, Obed Hernandez-Gomez

Natural Sciences and Mathematics | Faculty Scholarship

Environmental change can disturb natural associations between wildlife and microbial symbionts, in many cases to the detriment of host health. We used a North American terrestrial salamander system to assess how the skin microbiota of amphibians responds to wildfires. In northern California's redwood/oak forests, we assessed how recent wildfires affected the skin microbiota of three different salamander species (Taricha sp., Batrachoseps attenuatus, and Ensatina eschscholtzii) over two different sampling seasons in 2018 and 2021. We found species-specific responses to wildfire disturbance on the alpha diversity of the skin microbiota of terrestrial salamanders, although burning in general altered the composition of …

From The Organismal To Biosphere Levels: Environmental Impacts On The Amphibian Microbiota, Obed Hernandez-Gomez, Jessica Hua

Natural Sciences and Mathematics | Faculty Scholarship

This review summarizes the role of environmental factors on amphibian microbiotas at the organismal, population, community, ecosystem, and biosphere levels. At the organismal-level, tissue source, disease status, and experimental manipulations were the strongest predictors of variation in amphibian microbiotas. At the population-level, habitat quality, disease status, and ancestry were commonly documented as drivers of microbiota turnover. At the community-level, studies focused on how species’ niche influence microbiota structure and function. At the ecosystem-level, abiotic and biotic reservoirs were important contributors to microbiota structure. At the biosphere-level, databases, sample banks, and semi-natural experiments were commonly used to describe microbiota assembly mechanisms …

Distribution And Frequency Of Aquatic Oomycetes Throughout Marin County In Relation To Physical Chemical Water Parameters, Franki Crites

Natural Sciences and Mathematics | Biological Sciences Master's Theses

Oomycetes, also known as water molds, belong to the kingdom Stramenopila and are a well-known group of plant pathogens and saprophytes. Important species include Phytophthora ramorum (causal agent of sudden oak death), Pythium aphanidermatum (root rot), and Phytophthora infestans (late potato blight), all major threats to the environment, agriculture, and the economy. Although many oomycete species have been found in various water sources, little is known about the correlation between the distribution and frequency of oomycetes in aquatic environments and physical chemical water parameters. The objective of this study was to detect and identify aquatic oomycetes from Marin County using …

Fungi Associated With Herbaceous Plants In Coastal Northern California, Greg Huffman

Natural Sciences and Mathematics | Biological Sciences Master's Theses

The presence of fungal species associated with herbaceous plants was monitored in coastal Marin County, California, USA. The research involved a combination of field sampling surveys and data collection using a stratified random design, pathogen identification through microbiological and molecular analysis, and descriptive analysis and ordination of results. A total of two years of repeated sampling (four times a year) was organized to allow for the detection of seasonal differences in pathogen presence on aerial plant parts. The objective of this study was to identify microbial species present on herbaceous plants using ITS1 sequence analysis. Throughout March of 2018 to …

Sources And Toxicity Of Mercury In The San Francisco Bay Area, Spanning California And Beyond., Mietek Kolipinski, Mani Subramanian, Kristina Kristen, Steven Borish, Stacy Ditta

Natural Sciences and Mathematics | Faculty Scholarship

This report synthesizes and evaluates published scientific literature on the environmental occurrence and biomagnification of mercury with emphasis on the San Francisco Bay Area (SFBA), California. Mercury forms various compounds, well known for their toxicity in humans and environmental ecosystems. Elemental mercury is transported and distributed by air, water, and sediments. Through the metabolic processes of algae and bacteria, mercury is converted into organic compounds, such as methylmercury (MeHg), which then bioaccumulates up through trophic levels. In fish, it is found primarily in skeletal muscle, while in humans, the primary target organs are the brain and kidneys. Health concerns exist …

Chronic Cadmium Exposure Decreases The Dependency Of Mcf7 Breast Cancer Cells On Erα., Mathew Bloomfield, Maggie Louie

Natural Sciences and Mathematics | Faculty Scholarship

Cadmium is an environmental contaminant that can activate estrogen receptor alpha (ERα) and contribute to the development and progression of breast cancer. Our lab previously demonstrated that chronic cadmium exposure alters the expression of several ERα-responsive genes and increases the malignancy of breast cancer cells. Although these studies support cadmium's function as a hormone disrupter, the role of ERα in cadmium-induced breast cancer progression remains unclear. To address this, we modulated the expression of ERα and found that while the loss of ERα significantly impaired cancer cell growth, migration, invasion and anchorage-independent growth in both MCF7 and MCF7-Cd cells, cadmium-exposed …

Ethical Problems With Plastic In The Ocean, Brennan Cotter

Senior Theses

In the year 2018 this paper argues that plastic use and waste is destroying our oceans and that we should address the problem by fully adopting the principle and practices of sustainability. The first section outlines the advent of our plastic disposable culture. The second section gives evidence of how plastic waste is negatively affecting marine life. The third section draws from literature in environmental philosophy to develop the concept of sustainability, and the concluding section outlines several steps we can take as individuals and nations to practice sustainability.

Pine Needle Pyrolysis: Bio-Waste Into Biofuel, Alexandra Fuentes

Honors Theses

This project explores the alternate uses of biomass. In particular it focuses on pine needles as a source for biofuels. Pine needles are of interest because in certain Mountain communities they are collected and removed from residential properties. By removing the pine needles, communities create a “defensible space” to prevent wild fires from destroying homes and property. These needles are often placed in regional landfills. The South Tahoe Refuse and Recycling Services alone has more than 4,340 tons of pine needles dumped at their facility annually. This large amount of biomass can be a potential energy source.

The focus of …

Investigating The Effects Of Decreased Ph On The Intertidal Shore Crab, Hemigrapsus Nudus, Avni Gandhi

Honors Theses

Ocean acidification has emerged as an issue for marine organisms, due to increased levels of CO2 in the atmosphere. In particular, invertebrates with calcium carbonate exoskeletons seem to be at risk. Our research investigates the potential effect of decreased pH on the weight of Hemigrapsus nudus, a species of intertidal crab found in Northern California. Over a 6 week period, crabs were maintained in individual containers with recirculating chilled seawater at 12.7°C. The control aquaria was maintained at 8.1 pH, while the experimental aquaria averaged a pH of 7.5. Crabs were weighed at two week intervals, preliminary information shows the …

Pine Needle Pyrolysis: Bio-Waste Into Biofuel, Alexandra Fuentes

Scholarly and Creative Works Conference (2015 - 2021)

This project explores the alternate uses of biomass. In particular, it focuses on pine needles as a source for biofuels. Pine needles are of interest because in certain Mountain communities they are collected and removed from residential properties. By removing the pine needles, communities create a “defensible space” to prevent wild fires from destroying homes. These needles are often placed in regional landfills. The South Tahoe Refuse and Recycling Services alone has more than 4,340 tons of pine needles dumped at their facility annually. This large amount of biomass can be a potential energy source.

The focus of this research …

Potential Role Of Micro-Algae On Global Energy Supply, Sage Callaway-Keeley, Stephanie Huynh

Student Research Posters

The most effective ways to reduce CO2 emissions are to improve the energy efficiency of each economic sector and to reduce the cutting of tropical and temperate forests around the world. These options, however, may not fully reach their technical and economic potential due to various political and socioeconomic. The most practical of these is to increase CO2 sinks through photosynthesis in both standing tree biomass and in ocean primary producers. The use of marine algae as CO2 sinks is for large-scale CO2 mitigation: the use of phytoplankton through Fe fertilization and macro algal (kelp) farms, which can be used …

Biofuels: A Hands-On Approach, Learning The Potential Of Utilizing Non-Food Sources, Alexandra Ham, Gabrielle Pecora, Hoaithuong Bui, Timothy Camarella, Victor Pham, Marc Ting

Student Research Posters

The global energy economy is huge and thoughts of replacing large amounts of petroleum based fuels by massive levels of fermentation of grains are not realistic. On an energy basis what global agriculture produces for food will almost cover the energy demands if all of it is redirected to the production of fuels—either as alcohols for gasoline or as fat derivatives for diesel fuel. This means that chemical processes need to be developed that allow inclusion of non-food based agricultural and urban wastes as well as forest debris into the energy economy. These represent opportunities to capture new sources of …

Tao How? Asian Religions And The Problem Of Environmental Degradation, Philip Novak

Collected Faculty and Staff Scholarship

"Twenty-five years ago, Huston Smith wrote an article called Tao Now ¹ to enlist the help of traditional Chinese attitudes toward nature in expanding the West's environmental awareness. If my interrogative betrays a greater diffidence than his imperative, it is only because China, the land of the Tao, lacks an enviable environmental record. Sadly, it seems that the existence of noble cultural ideals regarding the environment, in India as well as China, have not been a sufficient gurantee of good stewardship." ~ from the article