ABSTRACTS
2019 National McNair Scholars Conference at UCLA
Researcher: Zoë Davis
Title: Lectin-based Biosensor for Detection of E. coli in Drinking Water
Research Focus: Bioengineering
School: University of Florida
Presentation Type: Oral Presentation
The aim of this study was to create an affordable, facile and field deployable biosensor that would allow individuals to test the quality of their own drinking water quickly and efficiently. We chose concanavalin A (ConA), a lectin found in the jackbean plant, as our biorecognition element because it is selective for mannose, a complex sugar found in abundance on the surface of E. coli cells. In this study, we laser scribed a polyimide film (Kapton tape) which was adhered to the emulsion side of photopaper to create our laser scribed graphene (LSG) electrodes. We then placed the electrodes in a solution containing a mixture of cupric sulfate and copper nanoparticles extracted from reclaimed e-waste. The particles were plated using gravity-assisted electrodeposition, followed by the addition of ConA bound via electrostatic interaction to the copper on the electrode surface. These electrodes were used for the detection of E. coli K-12 (ATCC 8739) as an initial stand in for pathogenic strains of bacteria. We conducted electrochemical impedance spectroscopy to measure the resistance on the working area of the electrode with just the cupric sulfate nanoparticles, with the lectin added, and finally with bacteria added. The lectin-bacteria complex causes agglutination, a phenomenon in which the bacteria, having a multitude of sugars on their surface, are able to bind to multiple lectins. We expected the bacteria to agglutinate on the surface of the electrode, causing the measured impedance (resistance) to increase for the bacterial run. In our preliminary studies, we have been able to obtain a discernable signal change in impedance with bacterial concentrations as low as 40 CFU/mL. This leads us to conclude that a lectin-based sensor is feasible for detecting pathogenic bacteria in drinking water. Our sensor is easy to use and made of readily obtained and affordable materials. Future work will include using this sensor on ‘real’ samples from the environment, streamlining and improving our sensitivity and selectivity, and eventually adding more lectins to use as a sort of ‘lectin library’ on the surface of our electrode.
Researcher: Elisabeth Rios-Brooks
Presentation Title: ¿Estás Ready?: Uncovering Afro-Latinx Identities through Language
Research Focus: Understanding how Afro-Latinx identities negotiate and enter between different ethnic and racial spaces through language.
School: University of Florida
Presentation Type: Oral Presentation
How do Afro-Latinx students navigate different cultural spaces and negotiate which linguistic conventions to employ at a given time? How can translanguaging be used to claim identity and cultural relevance in one’s community? This paper argues that language is an important factor in gaining social and cultural capital in communities where people are otherwise excluded or marginalized due to cultural differences (Bourdieu, 1991). Students whose identities do not fit within one racial or ethnic label are often expected to choose one or the other (Abrahams, 1972). This study aims to understand how Afro-Latinx students use their linguistic repertoire to enter between Latinx, White, and Black spaces and a mixture thereof. Latinx is defined as students who self-identify as both Black and Hispanic/Latinx. The methods employed in this investigation include hour-long semi-structured interviews to allow new ideas to enter into the conversation as a result of what the participant wants to share. The interviews aid in gaining insight into the cultural backgrounds of Afro-Latinx students who translanguage between Spanish and English and/or dialects of English at the University of Florida in the United States. These interviews also aid in providing a first-person narrative on students’ experiences.
Snowball sampling was used to reach other Afro-Latinx students. Moving forward, it is important to create spaces for different linguistic identities to coexist in a leveled playing field where all languages and dialects are treated equally.
Researcher: Jessica Ross
Title: Measures of unfair treatment in African Americans living in Tallahassee, Florida
Research focus: Social science
School: University of Florida
Presentation type: Oral presentation
Scientific studies show that over 50% of minorities report having experienced discrimination. Studies also reveal associations between discrimination and depressive symptoms, blood pressure and self-rated health. In this community-based participatory project in Tallahassee, Florida, we asked 178 African Americans about their experiences with discrimination, measured as experience of unfair treatment. We asked participants if they, or someone close to them, had experienced unfair treatment in nine social domains, such as in schools, on the job, and with law enforcement. Sixty-one percent of participants reported experiencing unfair treatment themselves, while 73% of participants reported someone close to them having experienced unfair treatment. Incidence of unfair treatment to others was most often experienced by close friends (29%), children (19%), and other relatives (18%). For participants who only knew someone who experienced unfair treatment, they most often reported unfair treatment on the job (44 %), by police (38%), and by the courts (27%). Male participants reported more experiences of discrimination than female participants (p = .01). Using our different measures of unfair treatment, we found associations with height, depressive symptoms, and weight. These results suggest that it is important to not only ask people about their experiences with unfair treatment, but also the experiences of those close to them.
Researcher: Jessica Ross
Presentation Title: Investigating discrimination among African Americans in Tallahassee, Florida using novel measures of unfair treatment
Research Focus: Social sciences
School: University of Florida
Presentation Type: Oral Presentation
Scientific studies show that over 50% of minorities report having experienced discrimination. Studies also reveal associations between discrimination and health, such as high blood pressure, depression, and self-rated health. In this community-based participatory project in Tallahassee, Florida, we asked 178 African Americans about their experiences with discrimination, measured as experiences of unfair treatment. We asked participants if they, or someone close to them, had experienced unfair treatment in nine social domains, such as in schools, on the job, and with law enforcement. Sixty-one percent of participants reported experiencing unfair treatment themselves (UT-Self). Even more participants (66%) reported that someone close to them had experienced unfair treatment (UT-Other). UT-Other was most often experienced by close friends (29%), children (19%), and other relatives (18%) of the study participants and was most often experienced through work (35%), financial activities (20%), and with their in-laws (20%). Male participants reported more UT-Self than female participants, but male and female participants reported equivalent levels of UT-Other. There was a positive association between participants’ height and both UT-Other and UT-Self and a positive association between weight and UT-Other. Greater stature is typically associated with beneficial characteristics, such as increased income and happiness, but in our study increased stature was associated with increased reports of unfair treatment.
Researcher: Ebony Taylor
Presentation Title: Large ants do not carry their fair share: maximal load-carrying performance of leaf-cutter ants (Atta cephalotes)
Research Focus: Biomechanics, Leaf-cutter ants, Power reserves
School: University of Florida
Presentation Type: Oral Presentation
Although ants are lauded for their strength, little is known about the limits of their load-carrying abilities. We determined the maximal load-carrying capacity of leaf-cutter ants by incrementally adding mass to the leaves they carried. Maximal load-carrying ability scaled isometrically with body size, indicating that larger ants had the capacity to lift the same proportion of their body mass as smaller ants (8.78 times body mass). However, larger ants were captured carrying leaf fragments that represented a lower proportion of their body mass compared with their smaller counterparts. Therefore, when selecting leaves, larger ants retained a higher proportion of their load-carrying capacity in reserve. This suggests that either larger ants require greater power reserves to overcome challenges they encounter along the trail or leaf-cutter ants do not select loads that maximize the overall leaf transport rate of the colony.