Abstract Submitted for Presentation

Week of Undergraduate Excellence
Late April, 2017
Oral Presentation, 15 minutes

Understanding Chimpanzee Trafficking with Population Genomics
In recent years, scientists in the fields of population genetics and ecology realize how genetic information can be tools to affect conservation policy[1]. However, during this time, environmental crime has only grown, becoming the fourth largest illegal crime sector and funding illegal cartels and terrorist organizations. One broad category in environmental crime is that of the illegal wildlife trade, and it involves the illegal poaching of animal for their meat and body parts as well as the illegal capture and trafficking of animals to be pets. In Cameroon, we see both of these activities taking place, with endangered chimpanzees being poached for bushmeat trade, and baby chimps being captured and trafficked internationally to be pets. Using a comprehensive genetic dataset of ~10,000 Single Nucleotide Polymorphisms and a variety of geospatial representations of human activities, we’ve developed a pipeline that can estimate the origins of chimpanzees confiscated from the illegal wildlife (and thus captured illegally) with a previously unseen resolution, evaluate how human activities such as logging; road topology; distance to protected areas; and industrial logging contribute to these illegal poaching events, and then project poaching risk over the entirety of the chimpanzees’ range in Cameroon. This work has the potential not only to better assess where conversation resources could be most efficiently deployed, but it also allows us to identify new hotspots for chimpanzee poaching, and craft policy that targets specific industries contributing most to the illegal wildlife trade.
[1] Genetic assignment of large seizures of elephant ivory reveals Africa’s major poaching hotspots. Wasser et al. (2015). Science  

The Phorce Awakens: Isolating and Characterizing Phage BobaPhett From A Mixed Population of Bacteriophages

Phage BobaPhett and his faithful ally Phage JangoPhett were extracted as a mixed population from a dirt sample collected from within the deep soil near Drexel’s Buckley Tennis Courts. There were challenges isolating these phages from each other, but due to differences in their morphology, phage cluster assignment and genome, we have successfully characterized both phage genomes. The genome of phage BobaPhett has been annotated: genes were identified and functions assigned using bioinformatics software including PECAAN, DNA Master, Starterator, PhagesDB Blast, NCBI Blast, Phamerator and HHPRED. Phage BobaPhett has the siphoviridae morphology and belongs to the F1cluster of bacteriophages. Its genome has 59,815 nucleotides, making up 106 genes. May the phorce be with you!

Climate change and rising sea levels are endangering coastal wetlands, which are well known to be essential to prevent coastline erosion and as nutrient buffers for benthic environments. As sea levels rise and salt marsh plants experience longer periods of inundation certain physiological mechanisms are necessary for plants to adapt to changing conditions. One such mechanism is the formation of aerenchyma, air spaces in the stems, roots, and rhizomes of wetland plants which allow for aerobic respiration during periods of inundation. Estuarine plants are experiencing increasingly high nutrient loads from riverine washout, particularly from nitrates due to fertilizer pollution. While the negative impact of nitrates on offshore benthic environments has been well documented, the impact of poor water quality on salt marshes has been inconclusive. Low nutrient availability has been shown to encourage the formation of aerenchyma in food plants such as rice and corn. If this is also the case for coastal marsh plants, poor water quality may prevent an important physiological process that can help these plants adapt to a changing climate. This study aims to examine the potential negative impact of high nutrient loads on the physiology of coastal marsh plants. Specifically, we focused on the formation of aerenchyma in the high marsh cordgrass species Spartina patens and its relationship to nutrient availability. We investigated this process using a controlled factorial experiment, in which we grew Spartina patens in a mesocosm to simulate tides, and subjected one group of plants to low nutrient conditions and one group to high nutrient conditions. We then compared the formation of aerenchyma in the roots of both groups using scanning electron microscopy. If aerenchyma formation is correlated to nutrient availability, this could clarify one variable leading to inconsistent results in previous studies on the effect of nutrient availability on salt marshes.

3D printers have been exposed as emitters of ultrafine particles (UFP’s) and potentially carcinogenic volatile organic compounds (VOC’s). [1] UFP’s are detrimental for human health because their small size allows them to travel through air-ways and deposit in the lungs, eventually making their way into the bloodstream.  For this reason, some commercially available 3D printers are equipped with recirculating air filters such as the AFINIA-H800 printers in Drexel’s innovation studio.  Using novel technology in the Efficient Time of Flight Aerosol Mass Spectrometer (EPToF-AMS), a detailed emission study is presented that highlights particle size distribution, chemical composition, and concentration for two types of 3D printer plastic filaments. [2] Furthermore, this study analyzes the effectiveness of the recirculating air filters through the comparison of size distributions.  EPToF-AMS particle size distributions were supported by Scanning Mobility Particle Sizing (SMPS) distributions and Transmission Electron Microscopy (TEM) images of the emitted particles.    

[1] Azimi, P.; Zhao, D.; Pouzet, C.; Crain, N. E.; Stephens, B., Emissions of Ultrafine Particles and Volatile Organic Compounds from Commercially Available Desktop Three-Dimensional Printers with Multiple Filaments. Environ Sci Technol 2016, 50 (3), 1260-8.

[2]  Campuzano, J. P.; Jimenez, J. L.; Kimmel, J. R.; Day, D. A.; Hu, W.; Sueper, D.; Knochenmuss, R.; Worsnop, D. R.; Jayne, J. T., Particle Time-of-Flight by Hadamard Transform (ePToF): A new high-duty-cycle approach to size-segregated and total aerosol mass measurements for the Aerodyne Aerosol Mass Spectrometer. American Geophysical Union, Fall Meeting 2014, 2014.

The study was conducted in the city of Heraklion, Crete in Greece at the Technological Educational Institute of Heraklion, a foremost agricultural university on the island of Crete, an institute that specializes in giving Greek and international students practical agricultural experience. This study examined the effectiveness of different concentrations of treated gray and black water for five different species of spice plants with a total of 150 plants in six different growing conditions (control versus black versus gray water, with each group divided into low and high water concentrations). Various measurements of these plants were taken such as height, length and width to create a data growth index over a period of four months, along with chlorophyll levels, blossom/flower counts, and water absorption speeds. The study provides evidence that plant growth was higher when irrigated with treated wastewater compared to the freshwater irrigation control group, and the number of blossoms of the plants were also higher. This effect should be studied in more detail in further experimentation, but is likely due to the anaerobic bacteria used to treat the plants. Additionally, the study also suggested that certain spices respond better to treated wastewater than others, with Dictamnus and Origanum responding well and Salvia responding poorly and showed high mortality. These results have potential to change the way water is irrigated around the world, especially in areas vulnerable to drought such as California, but more plants and crops should be studied for conclusive results.

Solar photovoltaic energy is a clean and renewable source of electricity that has been researched heavily over the past 30 years. However, cost, toxicity, and rarity of precursor elements still limit its widespread implementation. Antimony Sulfoiodide (SbSI) is a relatively unstudied ferroelectric with promising properties as a solar cell absorber.  

In this work, the semiconductor SbSI was synthesized hydrothermally to produce crystals that were 650 microns long and 30 microns in diameter on average, as measured by scanning electron microscopy. These microrods were synthesized from a published procedure [1], but had variances in pH and seeding, where a decrease in pH increased crystal size. X-ray diffraction confirmed the phase purity. Diffuse reflectance measurements revealed an indirect band gap of 1.85 eV, which is near the optimal range for solar cells. These preliminary results demonstrate the suitable properties of SbSI as an easily synthesized solar cell absorber material.[1] Chen, G., Li, W., Yu, Y., & Yang, Q. (2015). Fast and low-temperature synthesis of one-dimensional (1D) single-crystalline SbSI microrod for high performance photodetector. RSC Adv., 5(28), 21859-21864. doi:10.1039/c5ra01180a

Name of the event: Research Day 2015
Location of conference: Daskalakis Athletic Center
Date: May 1, 2015
Type of presentation: Poster Presentation
Title: Planitia Hellas Human Advanced Martian Environment (PHHAME)

This paper describes project Planitia-Hellas Human Advance Martian Environment (PHAME) which intends to support a settlement of 24 dwellers and achieve sustainability by the 40th year of its existence. This paper follows through the travel to Mars, the construction of habitat, and the fabrication of strong network communication. To meet the energy requirements, PHAME makes use of Solar and Wind energy harnessing technologies. Giving importance to the health and safety of the crew, the mission includes many precautions for effects such as the Bends and provides ways to perform surgeries in times of necessity. This paper also shines light upon reaping benefits from the regolith itself by mining and processing, along with procedures to follow during an emergency. All in all, PHAME provides a comprehensive plan for humans to finally colonize Mars.

Licorice is a popular natural sweetener used in a wide variety of items from candies to tobacco products. Although most people believe that this is a harmless substance, daily consumption can result in serious toxicity resulting from the plant's active ingredient glycyrrhizin. Over the years there have been many reported cases of hospitalization and even death as a result of excessive licorice intake. This presentation will address the historical significance of licorice, discuss the mechanisms of licorice toxicity, and present a case study of a real patient experience licorice poisoning.

Name of Event: Nerd Night at Drexel University
Date of Presentation: October 26, 2016
Title of Presentation: "It's a PAC, PAC, PAC, PAC World"

Invasive animals pose a serious threat to biodiversity and economic growth. Throughout the world, invasive species are one of the largest threats to biodiversity and environmental health. In West Virginia, two invasive species of crayfish, Orconectes rusticus and Orconectes virilis, have become increasingly common while threatening to displace native species and destroy aquatic habitats. Aggressive interactions favoring larger, invasive crayfish are thought to give these species advantages over indigenous crayfish. This research investigated behavioral interactions between indigenous species and O. rusticus and found that there was actually no significant difference in aggression between species or genera. This suggests other factors influence its ability to rapidly establish population in new environments. Using radio-telemetry, O. virilis were tracked in the field in order to understand ranging patterns and the dispersal potential of this species. Daily movement was much higher than expected and crayfish did not seem affected by the direction of current. Previously it was thought that crayfish primarily moved less than one meter per day, only migrating downstream when carried by currents. This research observed O. virilis able to move dozens of meters per day, unaffected by direction of current. Orconectid crayfish have been traditionally thought of as aggressive species spread by human introductions to new environments, but this work suggests a very different picture. The species studied did not seem to rely to on aggression to establish dominance, and ultimately may be able to disperse themselves more effectively than native species.