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CHEM2020LE35772 CHEM

POROUS SILICON NANOTUBES AS POTENTIAL VECTORS FOR SMALL INTERFERING RNA DELIVERY

Type: Graduate
Author(s): Nguyen Le Chemistry & Biochemistry
Advisor(s): Jeffery Coffer Chemistry & Biochemistry Giridhar Akkaraju Biology

In cancer therapy, nucleic acid-based therapeutic strategies have been extensively investigated to suppress mutated gene expression, thereby inhibiting cancer cell growth. Among the approaches, small interfering (siRNA)-mediated gene silencing has been envisaged as a promising therapeutic approach to silence specific gene expression by targeting mRNA of the unwanted gene for degradation, thereby readily controlling cellular functions. However, delivery of small interfering RNA (siRNA) has been known to encounter multiple challenging barriers, such as blood circulation and cellular internalization, thus limiting the potential merits of this therapeutic strategy. While non-viral vectors have been preferred owing in part to better immune system compatibilities, porous silicon (pSi) with various geometric shapes (e.g. platelet and discoid) have recently been demonstrated as exceptional delivery carriers of siRNA in various disease models. Here our initial in vitro studies show that silicon in a unique one-dimensional porous nanotube structure (pSiNTs) can serve as a promising vector for delivery of siRNA to limit target gene expression, thereby expanding the library of possible nanostructures of Si in delivery of siRNA.
In this work, we demonstrate that pSiNTs after being functionalized with 3-(aminopropyl)triethoxysilane (APTES) can deliver enhanced green fluorescence protein (EGFP)-targeting-siRNA via electrostatic conjugation and suppress EGFP expression in HeLa cervical cancer cells by up to 50%. Cytocompatibility and biodegradation of the functionalized pSiNT matrix upon siRNA delivery are characterized by ATP quantification assays (CellTiter Glo) and Transmission Electron Microscopy imaging (TEM) respectively. These results encourage further development of pSiNTs in therapeutic applications.

(Presentation is private)

ENSC2020AGPALO34894 ENSC

Improving habitats for bats: What makes a bat-friendly residential swimming pool?

Type: Graduate
Author(s): Elizabeth Agpalo Environmental Sciences
Advisor(s): Victoria Bennett Environmental Sciences

For urban environments to support bat communities, resources need to be readily available, such as water. For example, bats typically use urban water sources, such as drainage ditches, lakes, and ponds. However, in areas where temperatures are consistently high and rainfall limited, these sources tend to be ephemeral. During these periods, bats utilized residential swimming pools. If pools were more attractive to bats, we may be able to improve urban habitats for bats both in terms of abundance and species diversity. We, therefore, set out to determine whether size, shape (round of square), lighting, and treatment type (chlorine, salt, or mineral) encouraged bats to drink at pools. Thus, we conducted behavioral surveys at 14 pools using thermal cameras and acoustic detectors to record bat foraging and drinking activity. Our results demonstrated that while shape did not influence pool use, treatment type, lighting, and size did. With this information, we can better advise interested residents in urban neighborhoods how better to make their backyards more bat-friendly.

(Presentation is private)

GEOL2020ALLEN25238 GEOL

Illinois agriculture: An examination of the relationship between annual corn crop yield and the application of Atrazine.

Type: Graduate
Author(s): Dalton Allen Biology
Advisor(s): Esayas Gebremichael Geological Sciences

Herbicides are chemicals frequently used in agriculture to manage or remove unwanted vegetation (i.e., weeds) that may negatively impact crops through resource competition. Through the elimination of these competitors, losses in crop yield may be reduced thus increasing cropland productivity. Atrazine is an herbicide that is widely used in the United States for the control of weeds that is predominately applied in the agriculture of corn, sorghum, and sugarcane. This is of interest to Illinois agriculture, as according to the United States Department of Agriculture (USDA), Illinois is a major agricultural producer of corn and soybeans with corn accounting for 11 million of Illinois’ 27 million acres of cropland. Further, Illinois possesses an agricultural industry that produces more than $19 billion annually of which corn accounts for more than 50 percent. It is due to the economic importance of corn crops to the state of Illinois and the widespread use of Atrazine in the agriculture of corn, that this project seeks to examine the relationship between Illinois annual corn crop yields and Atrazine application. This relationship will be assessed through analysis of spatial data acquired from the USDA for Illinois Atrazine application and corn crop yield.

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GEOL2020PRINES56945 GEOL

U-PB DETRITAL ZIRCONS OF SYNOROGENIC CARBONIFEROUS DEEP-WATER CLASTIC DEPOSITS IN THE OUACHITA MOUNTAINS, ARKANSAS, UNITED STATES

Type: Graduate
Author(s): Shaun Prines Geological Sciences Walter Manger Geological Sciences Xiangyang Xie Geological Sciences
Advisor(s): Xiangyang Xie Geological Sciences

The southern margin of the North American continent transformed from a passive margin to an
active margin during the Ouachita orogeny. Thick and near–continuous Paleozoic successions in
the Ouachita Mountains provide a unique opportunity to document changes in both
sedimentation and tectonics. In contrast to well-documented Taconic, Acadian, and Alleghenian
orogenic events, limited detrital zircon studies of the Ouachita orogeny and associated
successions have been published, and sediment sources of these deep-water, synorogenic clastics
remain less constrained.
In this study, a total of six outcrop samples (n=617) from the Mississippian Stanley Group and
Lower-Middle Pennsylvanian Jackfork and Johns Valley Groups were collected and processed
for U-Pb detrital zircon geochronologic analyses to depict sediment sources and dispersal
patterns during the Ouachita orogeny. Results show that the age distributions of the
Carboniferous deep-water clastic deposits in the Ouachita Mountains are characterized by major
peaks of the Paleozoic (~350-500 Ma), Grenville (~900-1350 Ma), and Midcontinental GraniteRhyolite (~1350-1500 Ma), minor peaks of Yavapai-Mazatzal (~1600-1800 Ma) and Superior (>
~2500 Ma) provinces. These deep water clastics share great similarities with the Appalachian
sources and are likely derived from similar sources. From the Mississippian Stanley Group to the
Pennsylvanian Jackfork and Johns Valley Groups, the Yavapai-Mazatzal population shows
marked enrichment (up to ~12%), suggesting Precambrian basement uplifts, possibly related to
the Ancestral Rockies to the northwest, might be another potential source. Compilation and
comparison show the Neoproterozoic age population (~550-800 Ma), most likely associated with
the peri-Gondwana terrane to the south, ranges from 3% to 35% within the Mississippian Stanley
Group. The variation indicates that the Stanley Group may have strong but short-lived local
contribution from the Gondwana terrane in addition to the regional Appalachian sources.
Overall, despite its proximal location, these Carboniferous deep-water clastic deposits in the
Ouachita Mountains received limited contribution from the Ouachita orogenic belt itself.

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GEOL2020TUCKER62356 GEOL

Trail Network Analysis of the TCU Tropical Biology Station

Type: Graduate
Author(s): Mary Tucker Geological Sciences
Advisor(s): Esayas Gebremichael Geological Sciences Dean Williams Biology

The new world tropics represent an area of unparalleled biodiversity. Unfortunately, it also represents an area of increasing habitat loss and consequently is in dire need of protection and conservation. The TCU San Ramon Tropical Biology Station located on the Caribbean slope of Costa Rica protects 100 hectares of primary and secondary forest and is a unique and ideal location for studying tropical biology. In the summer of 2018, we mapped an updated trail network at the station using a Bad elf sub-meter GNSS receiver in conjunction with Arc Collector. For this project we analyzed the distance each trail traveled through the 3 habitat types found at the station (primary forest, secondary forest, and pasture land), which will be used to aid the sampling efforts of my Master’s thesis project examining how mixed-species foraging flocks utilize the habitat protected by the station.

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