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2017-2019 UC LEADS Cohort

2017-2019 Cohort

Tamunotubo George

Major: Mechanical Engineering

Home City: Fontana, CA

Contact: tgeorge3@ucmerced.edu

Faculty Mentor: Professor Francois Blanchette 

Tamunotubo George is a second-year undergraduate student from Fontana, CA. Expected to graduate in Spring 2019 with a BS in Mechanical Engineering. Tamunotubo is commonly referred to as Tam. Tam has always wanted to affect positively the world in a big way, so when he arrived at college, he strived for opportunities that would better him academically and professionally. Serving as an officer of NSBE, ASME and Vanguard, Tam has been fortunate enough to meet good people and make connections that can only further his progress. He surrounds himself with people who believe in hard work and share most of his core values. Also, Tam has a great love for soccer. He loves watching it, playing it, talking about it, anything at all. Lastly, Tam hopes to achieve a Master's Degree in Mechanical Engineering, and his ultimate goal is to be part of the next wave of minds who bring the next big innovation into the world. 
 
Oil Droplets, Surfactants and the Effect of the Ratio of Adsorption and Desorption Rate on Rise Velocity
 
Tamunotubo George, Francois Blanchette, PhD, and David Matin, PhD; School of Engineering, University of California, Merced
 
In the case of oil spillage, it is important to know how fast oil droplets reach the surface of the ocean. Here, we simulated numerically rising oil droplets in the ocean. Simulations were run using a C-code that calculated the rise of the oil drop. We focused on the combined effects of the ocean’s density stratification and the presence of surface-active molecules (surfactants). The effects of the ratio of adsorption and desorption rates of the drop’s rise velocity were quantified. Our results show that they are still running at the moment.

Jessica Lopez Lara

Major: Chemistry 

Home City: Elk Grove, CA

Contact: jlopezlara@ucmerced.edu

Faculty Mentor: Professor Benjamin J Stokes

Jessica Lopez is a third year undergraduate student from the city of Elk Grove, CA and is expected to graduate in the spring of 2019. Jessica started to take the necessary steps to become an active student at the University of California, Merced by becoming involved on campus and reaching out to the community around her. She joined the Society of Hispanic Professional Engineers-Ingenieros Unidos, where Jessica works under the Outreach committee. Under the committee, she volunteers her time to mentor children at various elementary schools. Through this, she believes that she can give back to the community by inspiring the future generations of students to go onto college. On her free time, she enjoys drawing fashion sketches and collecting Vogue magazines. Jessica's goals are to obtain her PhD in Chemistry and empower young women of all majors, especially Latinas, to achieve a college degree. 
 
Synthesis of Tetralins Via Brønsted Acid-Catalyzed Intramolecular Hydroarylation of Alkenes: An Investigation of Regioselectivity, and Limitations
 
Jessica Lopez Lara, Amir Keshavarz, and Benjamin J. Stokes, PhD; School of Natural Sciences, University of California, Merced
 
We recently reported a method for the synthesis of polysubstituted indanes through intramolecular hydroxylation of β-benzylstyrenes using triphenylmethylium tetrakis(pentafluorophenyl)borate (TPFPB) as an easily handled Brønsted acid precatalyst. Based on surprising regioselectivity trends observed in the aforementioned reactions, we were inspired to study the regioselectivity, scope, and limitations of cyclization in new systems-herein, β-homobenzylstyrenes, β-homobenzylbutenes, and β- homobenzylpropenes. Our approach provides access to a wide range of polysubstituted tetralins that make up the backbone of many pharmaceutical drugs. The pregioselectivity outcomes observed in our studies contribute to an improved general understanding of electronic and steric effects in Frieden-Crafts-type electrophilic aromatic substitution reactions.

Alejandra Martinez Lopez

Major: Environmental Engineering

Home City: San Diego, CA

Contact: amartinezlopez2@ucmerced.edu

Faculty Mentor: Professor Marc Bautel

Alejandra is a third year transfer student from San Diego. She will be graduating in Fall 2018 with a BS in Environmental Engineering. Alejandra was very involved in her community college and has done research at UCSD where she grew her interest in graduate school. Now she will be conducting research at UCM with Dr. Beutel where she will focus on Mercury in the environment. She is very passionate about climate change and she feels a strong connection with her major because she hopes to change the world. Alejandra is also a strong advocate for women in STEM and she loves volunteering in outreach events that motivate young girls. Alejandra wants to earn her Masters in sustainable energy and she hopes that one day she goes back to San Diego to mentor those students like her that want to pursue a STEM career. 
 
Biomonitoring of Atmospheric Mercury Pollution Using Lichen at the Monte Amiata Mercury Mining District in Southern Tuscany, Italy
 
Alejandra Martinez Lopez, Jaycee Martinez, and Marc Beutel, PhD; School of Engineering, University of California, Merced
 
We recently reported a method for the synthesis of polysubstituted indanes through intramolecular hydroxylation of β-benzylstyrenes using triphenylmethylium tetrakis(pentafluorophenyl)borate (TPFPB) as an easily handled Brønsted acid precatalyst. Based on surprising regioselectivity trends observed in the aforementioned reactions, we were inspired to study the regioselectivity, scope, and limitations of cyclization in new systems-herein, β-homobenzylstyrenes, β-homobenzylbutenes, and β- homobenzylpropenes. Our approach provides access to a wide range of polysubstituted tetralins that make up the backbone of many pharmaceutical drugs. The pregioselectivity outcomes observed in our studies contribute to an improved general understanding of electronic and steric effects in Frieden-Crafts-type electrophilic aromatic substitution reactions.

Yulissa Perez Rojas

Major: Earth System Science

Home City: Santa Barbara, CA

Contact: yperezrojas@ucmerced.edu

Faculty Mentor: Professor Teamrat Ghezzehei

Yulissa Perez Rojas is a third year undergraduate student at the University of California, Merced. She is highly motivated to get her BS in Earth Systems Science, with a minor in Community Research and Service by Spring semester of 2019. Yulissa started to get involved with research before she was a senior in high school. A life accomplishment that she is extremely proud of was when she tested water hardness in UCSC with a chemistry professor in 2014. After that experience, Yulissa realized she wanted to become a researcher and obtain a Ph.D. in Environmental Conservation. She dreams of working for the National Oceanic and Atmospheric Administration (NOAA) to advance the knowledge of climate and conservation of marine ecosystems. In order for Yulissa to achieve her goals, she plans to undertake more research opportunities, network with graduate students and professors, grow as the Secretary for SACNAS, and continue to volunteer for Sierra Foothill Conservancy. 
 
How Does the Addition of a Cover Crop and its Residue Affects Soil Aggregation and Soil Organic Carbon in a Silty Clay Loam Soil?
 
Yulissa Perez Rojas, Nathaniel A. Bogie, Asmeret Asefaw Berhe, and Teamrat A. Ghezzehei, PhD; School of Natural Sciences, University of California, Merced
 
ncreased soil aggregation is associated with soil health and productivity as a consequence of increasing infiltrability, water holding capacity, and microbial activity. Aggregation helps in storage and stabilization of carbon. However, as the intensity of cultivation increases, the amount of carbon and the stability of soil aggregates can decrease. An existing challenge that we are facing today is how to increase carbon stabilization and cycling in agricultural lands without reducing productivity. The purpose of this study was to investigate how carbon and the stability of soil aggregates differ in a cover crop (CC) and a non-cover crop (NCC) field before, during, and after harvesting tomatoes. Samples were collected from Russell Ranch Sustainable Agricultural Facility in Davis, CA at four depths (0-10, 10-20, 20-30, and 30-50cm) (n=4). Each sample was separated into four aggregate sizes (>2000, 250–2000, 53–250, and 53 <μm) by wet sieving to investigate carbon and nitrogen content. Preliminary results indicate a higher fraction for the >2000μm macroaggregates at the 0-10 depth in CC vs. NCC (19% and 1%, respectively). For all depths between 0 and 20cm the amount of free light biomass was over 100% higher in the CC compared to the NCC treatment. In the 250-2000μm macroaggregate size class the NCC field contains a slightly elevated fraction of aggregates. This aggregation data, along with the forthcoming C and N data, will allow us understand the effect of cover cropping on soil structure and help make management decisions for the future of agriculture in a changing climate.

Felipe Rodriguez

Major: Biological Sciences

Home City: Porterville, CA

Contact: frodriguez33@ucmerced.edu

Faculty Mentor: Professor Kirk Jensen

Felipe Rodriguez is an upcoming third year undergraduate student from Porterville, CA. Felipe is expected to graduate in Spring 2019 with a BS in Biology with an emphasis in Immunology and Microbiology. Felipe has already begun to make his mark at University of California, Merced by conducting research with Dr. Jensen in Toxoplasma gondii. As a member of AMSA, past Community Scholar and a future Academic Scholar for the Fiat Lux program, Felipe knows it is important to give back to the community by being a role model and leading students through college as it may be difficult for them to adjust to the new environment. In Felipe's free time he likes to travel and watch movies with his best friend. Felipe aspires to achieve a PhD in Immunology and Microbiology at UCLA or UC Davis. 
 
Does ROP5C Hinder CD8 T Cell Response?
 
Felipe Rodriguez, Angel Kongsomboonvech, Anh Diep, Brandon Justice, and Kirk Jensen, PhD; School of Natural Sciences, University of California, Merced
 
Pluripotent stem cells (PSC) have the ability to differentiate into varying cells types. In vitro, PSC can differentiate into vascular smooth muscle cells (VSMC) which create a solid source for cells. Human induced pluripotent stem cells (HiPS) have the plasticity to differentiate into VSMC in vitro via different growth factors. In the first part of the experiment, HiPS were induced into vascular progenitor cells using vascular endothelial growth factor (VEGF) and bone morphogenetic protein 4 (BMP4). Vascular progenitor cells were then induced into VSMC using transforming growth factor beta 1 (TGF-1). TGF-1 was supplied to the cells via the feeding media at five varying concentrations. The goal of the experiment was to see how varying growth factor concentrations such as TGF-1 as well as time or maturation affect HiPS differentiation into VSMC. The success of the VSMC differentiation was be measured using three different markers. The three markers that were traced are alpha smooth muscle actin (SMA), calponin heavy metal (CNN1), and smooth muscle myosin heavy metal chain (SMMHC). As the cells mature the expected dominant markers are SMA, CNN1, and SMMHC; respectively. Results will demonstrate how varying TGF-1 concentrations and time will affect VSMC fate. Optimizing VSMC fate may allow for the future use in disease modeling or regenerative medicine.

Gabriela Sanchez

Major: Bioengineering 

Home City: Stockton, CA

Contact: gsanchez33@ucmerced.edu

Faculty Mentor: Professor Kara McCloskey

Gabriela Sanchez is a second-year undergraduate student from Stockton, CA. Expected to graduate in Spring 2019 with a BS in Bioengineering, Gabriela has begun preparing herself at the University of California, Merced by conducting research and by being an active member of SHPE and BMES. As a member of the organizations, Gabriela believes it is important to give back and reach out to the community, she thinks it is the best way to make a difference in the community. In her time back home she enjoys returning to her folkloric dance group and performing for her community as she enjoys inspiring the youth to pursue recreational activities. She aspires to achieve a Ph.D. in bioengineering, and her dream is to become a strong role model that can inspire others in her community, especially young women, to follow their dreams. She wants them to know that their background is not a barrier to the accomplishments they can achieve with a pursued education. 
 
Optimization of Vacular Smooth Muscle Cell Fate via Different Growth Factors Concentrations
 
Gabriela Sanchez, Edwin M. Shen, and Kara E. McCloskey, PhD; School of Engineering, University of California, Merced
 
Pluripotent stem cells (PSC) have the ability to differentiate into a variety of cell types, including vascular smooth muscle cells (VSMC). The McCloskey laboratory is interested in directing human induced pluripotent stem cells (hiPS) into VSMC in vitro using a staged methodology. In the first part of the experiment, hiPS were induced into vascular progenitor cells using vascular endothelial growth factor (VEGF) and bone morphogenetic protein 4 (BMP4). Vascular progenitor cells were then directed towards VSMC specification over time using transforming growth factor beta 1 (TGF-β1) and platelet-derived growth factor beta beta (PDGF-ββ) at five varying concentrations. The goal of the experiment was to see how varying growth factor concentrations such as TGF-β1 and PDGF-ββ as well as time or maturation affect hiPS differentiation into VSMC. The VSMC phenotype was measured using three different markers: alpha smooth muscle actin (Alpha-SMA), calponin (CNN1), and smooth muscle myosin heavy chain (SMMHC). Results will demonstrate how varying growth factor concentrations and time affect VSMC fate in order to generate highly pure VSMC populations for building tissue engineered vasculature products.