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- All Subjects: Physics
- Creators: School of Mathematical and Statistical Sciences
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Description
Preliminary feasibility studies for two possible experiments with the GlueX detector, installed in Hall D of Jefferson Laboratory, are presented. First, a general study of the feasibility of detecting the ηC at the current hadronic rate is discussed, without regard for detector or reconstruction efficiency. Second, a study of the use of statistical methods in studying exotic meson candidates is outlined, describing methods and providing preliminary data on their efficacy.
ContributorsPrather, Benjamin Scott (Author) / Ritchie, Barry G. (Thesis director) / Dugger, Michael (Committee member) / Barrett, The Honors College (Contributor) / School of Mathematical and Statistical Sciences (Contributor) / Department of Physics (Contributor)
Created2015-05
Description
Currently in synthetic biology only the Las, Lux, and Rhl quorum sensing pathways have been adapted for broad engineering use. Quorum sensing allows a means of cell to cell communication in which a designated sender cell produces quorum sensing molecules that modify gene expression of a designated receiver cell. While useful, these three quorum sensing pathways exhibit a nontrivial level of crosstalk, hindering robust engineering and leading to unexpected effects in a given design. To address the lack of orthogonality among these three quorum sensing pathways, previous scientists have attempted to perform directed evolution on components of the quorum sensing pathway. While a powerful tool, directed evolution is limited by the subspace that is defined by the protein. For this reason, we take an evolutionary biology approach to identify new orthogonal quorum sensing networks and test these networks for cross-talk with currently-used networks. By charting characteristics of acyl homoserine lactone (AHL) molecules used across quorum sensing pathways in nature, we have identified favorable candidate pathways likely to display orthogonality. These include Aub, Bja, Bra, Cer, Esa, Las, Lux, Rhl, Rpa, and Sin, which we have begun constructing and testing. Our synthetic circuits express GFP in response to a quorum sensing molecule, allowing quantitative measurement of orthogonality between pairs. By determining orthogonal quorum sensing pairs, we hope to identify and adapt novel quorum sensing pathways for robust use in higher-order genetic circuits.
ContributorsMuller, Ryan (Author) / Haynes, Karmella (Thesis director) / Wang, Xiao (Committee member) / Barrett, The Honors College (Contributor) / School of Mathematical and Statistical Sciences (Contributor) / Department of Chemistry and Biochemistry (Contributor) / School of Life Sciences (Contributor)
Created2015-05
Description
Three populations of experimentally evolved Drosophila melanogaster populations made up of high temperature (H, constant 25 ᵒC), low temperature (C, constant 16 ᵒC) and temporal homogeneity (T, environment changes between 16 ᵒC and 25 ᵒC) were prepared and assayed to determine difference in citrate synthase activity. Between the three groups, the results were inconclusive: the resulting reaction rates in units of nmol min-1mgfly-1 were 81.8 + 20.6, 101 + 15.6, and 96.9 + 25.2 for the hot (H), cold (C), and temporally homogeneous (T) groups, respectively. We conclude that the high associated variability was due to a lack of control regarding the collection time of the experimentally evolved Drosophila.
ContributorsBelohlavek, David (Author) / Angilletta, Michael (Thesis director) / Francisco, Wilson (Committee member) / Barrett, The Honors College (Contributor) / Department of Chemistry and Biochemistry (Contributor)
Created2015-05
Description
Honey bees (Apis mellifera) are responsible for pollinating nearly 80\% of all pollinated plants, meaning humans depend on honey bees to pollinate many staple crops. The success or failure of a colony is vital to global food production. There are various complex factors that can contribute to a colony's failure, including pesticides. Neonicotoids are a popular pesticide that have been used in recent times. In this study we concern ourselves with pesticides and its impact on honey bee colonies. Previous investigations that we draw significant inspiration from include Khoury et Al's \emph{A Quantitative Model of Honey Bee Colony Population Dynamics}, Henry et Al's \emph{A Common Pesticide Decreases Foraging Success and Survival in Honey Bees}, and Brown's \emph{ Mathematical Models of Honey Bee Populations: Rapid Population Decline}. In this project we extend a mathematical model to investigate the impact of pesticides on a honey bee colony, with birth rates and death rates being dependent on pesticides, and we see how these death rates influence the growth of a colony. Our studies have found an equilibrium point that depends on pesticides. Trace amounts of pesticide are detrimental as they not only affect death rates, but birth rates as well.
ContributorsSalinas, Armando (Author) / Vaz, Paul (Thesis director) / Jones, Donald (Committee member) / School of Mathematical and Statistical Sciences (Contributor) / School of International Letters and Cultures (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
Description
We develop the mathematical tools necessary to describe the interaction between a resonant pole and a threshold energy. Using these tools, we analyze the properties an opening threshold has on the resonant pole mass (the "cusp effect"), leading to an effect called "pole-dragging." We consider two models for resonances: a molecular, mesonic model, and a color-nonsinglet diquark plus antidiquark model. Then, we compare the pole-dragging effect due to these models on the masses of the f0(980), the X(3872), and the Zb(10610) and compare the effect's magnitude. We find that, while for lower masses, such as the f 0 (980), the pole-dragging effect that arises from the molecular model is more significant, the diquark model's pole-dragging effect becomes dominant at higher masses such as those of the X(3872) and the Z b (10610). This indicates that for lower threshold energies, diquark models may have less significant effects on predicted resonant masses than mesonic models, but for higher threshold energies, it is necessary to include the pole-dragging effect due to a diquark threshold in high-precision QCD calculations.
ContributorsBlitz, Samuel Harris (Author) / Richard, Lebed (Thesis director) / Comfort, Joseph (Committee member) / School of Mathematical and Statistical Sciences (Contributor) / Department of Physics (Contributor) / Barrett, The Honors College (Contributor)
Created2015-05
Description
Since the acceptance of Einstein's special theory of relativity by the scientific community, authors of science fiction have used the concept of time dilation to permit seemingly impossible feats. Simple spacecraft acceleration schemes involving time dilation have been considered by scientists and fiction writers alike. Using an original Java program based upon the differential equations for special relativistic kinematics, several scenarios for round trip excursions at relativistic speeds are calculated and compared, with particular attention to energy budget and relativistic time passage in all relevant frames.
ContributorsAlfson, Jonathan William (Author) / Jacob, Richard (Thesis director) / Covatto, Carl (Committee member) / Foy, Joseph (Committee member) / Barrett, The Honors College (Contributor) / School of Mathematical and Statistical Sciences (Contributor) / Department of Physics (Contributor)
Created2015-05
Description
Professor Alarcon’s lab is producing proton beam detectors, and this project is focused on informing the decision as to which layout of detector is more effective at producing an accurate backprojection for an equal number of data channels. The comparison is between “square pad” detectors and “wire pad” detectors. The square pad detector consists of a grid of square pads all of identical size, that each collect their own data. The wire pad detector consists of large rectangular pads that span the entire detector in one direction, with 2 additional layers of identical pads each rotated by 60° from the previous. In order to test each design Python was used to simulate Gaussian beams of varying amplitudes, position and size and integrate them in each of the two methods. They were then backprojected and fit to a Gaussian function and the error between the backprojected parameters and the original parameters of the beam were measured.
ContributorsFoley, Brendan (Author) / Alarcon, Ricardo (Thesis director) / Galyaev, Eugene (Committee member) / Department of Physics (Contributor) / School of Mathematical and Statistical Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
The current observable universe is made of matter due to baryon/antibaryon asymmetry. The Deep Underground Neutrino Experiment is an international experiment through the Fermi National Accelerator Laboratory that will study neutrinos. In this study, the detection efficiency for low energy supernova neutrinos was examined in order to improve energy reconstruction for neutrino energies less than 40 MeV. To do this, supernova neutrino events were simulated using the LarSoft simulation package with and without background. The ratios between the true data and reconstructed data were compared to identify the deficiencies of the detector, which were found to be low energies and high drift times. The ratio between the true and reconstructed data was improved by applying the physical limits of the detector. The efficiency of the improved ratio of the clean data was found to be 93.2% and the efficiency of the improved ratio with the data with background was 82.6%. The study suggests that a second photon detector at the far wall of the detector would help improve the resolutions at high drift times and low neutrino energies.
ContributorsProcter-Murphy, Rachel Grace (Co-author) / Procter-Murphy, Rachel (Co-author) / Ritchie, Barry (Thesis director) / LoSecco, John (Committee member) / School of Earth and Space Exploration (Contributor) / Department of Physics (Contributor) / School of Mathematical and Statistical Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
Description
In this project, we created a code that was able to simulate the dynamics of a three site Hubbard model ring connected to an infinite dissipative bath and driven by an electric field. We utilized the master equation approach, which will one day be able to be implemented efficiently on a quantum computer. For now we used classical computing to model one of the simplest nontrivial driven dissipative systems. This will serve as a verification of the master equation method and a baseline to test against when we are able to implement it on a quantum computer. For this report, we will mainly focus on classifying the DC component of the current around our ring. We notice several expected characteristics of this DC current including an inverse square tail at large values of the electric field and a linear response region at small values of the electric field.
ContributorsJohnson, Michael (Author) / Chamberlin, Ralph (Thesis director) / Ritchie, Barry (Committee member) / School of Mathematical and Statistical Sciences (Contributor) / Department of Physics (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
Description
Although extracellular throughout their lifecycle, trypanosomes are able to persist despite strong host immune responses through a process known as antigenic variation involving a large, highly diverse family of surface glycopro- tein (VSG) genes, only one of which is expressed at a time. Previous studies have used mathematical models to investigate the relationship between VSG switching and the dynamics of trypanosome infections, but none have explored the role of multiple VSG expression sites or the contribution of mosaic gene conversion events involving VSG pseudogenes.
ContributorsKoury, Michael Andrew (Author) / Taylor, Jesse (Thesis director) / Gumel, Abba (Committee member) / Department of Physics (Contributor) / School of Mathematical and Statistical Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05