Matching Items (157)
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Description
The focus of human decomposition studies has traditionally been on how external factors affect the decomposition of a body. There is much less literature on how the decomposition of a human cadaver affects its local ecosystem. This study attempts to address the knowledge gap in current literature regarding how the

The focus of human decomposition studies has traditionally been on how external factors affect the decomposition of a body. There is much less literature on how the decomposition of a human cadaver affects its local ecosystem. This study attempts to address the knowledge gap in current literature regarding how the decomposition of human cadavers affects the bioavailability of essential plant nutrients (P, K, Ca, Fe, C and N) as well as toxins (As and Pb) in soil. By studying the bioavailability of plant nutrients, especially nitrogen, and toxins, this research hopes to inform new technologies and techniques for locating clandestine gravesites. The objectives of this study were twofold: 1) determine whether soils exposed to cadaveric decomposition can be visually distinguished from one another via macroscopic and microscopic observation and 2) observe general changes in nutrient and toxic element bioavailability and changes in carbon and nitrogen isotope ratios over time as well as spatially across a body. Visual analyses of soil samples, both macro- and microscopically did not show potential in distinguishing soil exposed to cadaver decomposition from unexposed soil. Relative bioavailability as well as overall bioavailable concentrations of both plant nutrients and toxins were highly elevated after 12 months. Toxins, such as As and Pb, tended to have greater bioavailable concentrations at the near-torso positions, though no consistent spatial trends between nutrient bioavailable concentrations were observed between the three individuals. Nitrogen concentrations and nitrogen isotope (δ15N) ratios show strong potential as markers of clandestine graves throughout the study period. While this research demonstrates further need to uncover what factors influence bioavailability of elements in gravesoil, it shows that the bioavailability of plant nutrients and toxins as well as δ15N ratios are greatly affected by cadaver decomposition, and emerging technologies in gravesite detection based on plant or soil changes have a solid foundation.
ContributorsAnderson, Sara Rae (Author) / Kobojek, Kimberly (Thesis director) / Gordon, Gwyneth (Committee member) / School of Mathematical and Natural Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
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Description
Criminal Justice is a complex subject matter, and not everyone agrees on the way a criminal justice system ought to function. But one feature that is common to virtually all forms of proposed justice systems is that a true justice system treats people ethically. The question, then, is how a

Criminal Justice is a complex subject matter, and not everyone agrees on the way a criminal justice system ought to function. But one feature that is common to virtually all forms of proposed justice systems is that a true justice system treats people ethically. The question, then, is how a justice system can achieve this. This investigation analyzed two ethical theories, Kantianism and Utilitarianism, to determine which one would be better suited for guiding a criminal justice system on how to treat the people involved ethically. This investigation focused on applying the two theories to the U.S. Criminal Justice System in particular.
Kantianism is a duty-based moral theory in which actions have an intrinsic moral worth. This means certain actions are morally right and other are morally wrong, regardless of the intended or realized consequences. The theory relies on the categorical imperative to judge the morality of certain actions. It states that an action is moral if its maxim can be willed universal law and if it avoids treating people as merely a means. In contrast, Utilitarianism is a consequentialist theory which focuses on the consequences of an action in judging moral worth. In Utilitarianism, the morally correct action is the one which will maximize utility; that is to say, the morally right action is the one which will produce the greatest amount of happiness and minimize the amount of pain for the greatest number of people.
After applying these two theories to moral dilemmas facing the U.S. Criminal Justice System, including the appropriate collection of DNA evidence, the use of police deception, and the use of criminal punishments such as solitary confinement or the death penalty, it was clear that Kantianism was the ethical theory best suited for guiding the system in treating people ethically. This is because Kantianism’s focus on the intrinsic moral worth of an action rather than its consequences leaves less room for ambiguity than does Utilitarianism.
ContributorsMorett, Xavier Laakea (Author) / Manninen, Bertha (Thesis director) / Kimberly, Kobojek (Committee member) / School of Criminology and Criminal Justice (Contributor) / School of Mathematical and Natural Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
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Description
Calcium is the only ion capable of triggering electrical and chemical reactions in cells which are part of essential biomolecular processes, such as gene transcription and ion flux. Calcium homeostasis, the control of concentration levels, is therefore crucial for the proper functioning of cells. For example, cardiomyocytes, the cells that

Calcium is the only ion capable of triggering electrical and chemical reactions in cells which are part of essential biomolecular processes, such as gene transcription and ion flux. Calcium homeostasis, the control of concentration levels, is therefore crucial for the proper functioning of cells. For example, cardiomyocytes, the cells that form cardiac muscle, rely on calcium transfer process to produce muscle contraction.
The purpose of this work is to study aspects of calcium homeostasis in the model organism Saccharomyces cerevisiae, common yeast. Using luminometric techniques, the response of the yeast was monitored against a set of changes in the environment calcium abundance. The results indicate a complex response as both increase and decreases of external calcium induce elevations in cytosolic calcium concentrations.
Calcium is transferred across compartments by means of channels. In Saccharomyces cerevisiae, many of them have been identified; Cch1p-Mid1p, Vcx1p, Pmc1p, Pmr1p, and Yvc1p. Their participation in calcium homeostasis is well established. Observations of cytosolic calcium increase after a hypertonic shock are mainly associated with influx of ions from the environment though the Cch1p-Mid1p. This process is generally considered as driven by calcium concentration gradients. However, recent studies have suggested that the plasma membrane channel, Cch1p-Mid1p, may possess more sophisticated regulation and sensory mechanisms. The results of our experiments support these ideas.
We carried out experiments that subjected yeast to multiple shocks: a hypertonic shock followed by either a second hypertonic shock, a hypotonic shock, or a yeast dilution pulse where the solution volume increases by the calcium concentration has only a small change. The cytosolic calcium concentration of a yeast population was monitored via luminometry.
The main result of this study is the observation of an unexpected response to the combination of hypertonic and hypotonic shocks. In this case it was observed that the cytosolic calcium concentration increased after both shocks. This indicates that cytosolic calcium increases are not solely driven by the presence of concentration gradients. The response after the hypotonic pulse arises from more complex mechanisms that may include sensor activity at the membrane channels and the release of calcium from internal storages.
ContributorsMintz, David Anthony (Co-author) / Parker, Augustus (Co-author) / Solis, Francisco (Thesis director) / Marshall, Pamela (Committee member) / School of Mathematical and Natural Sciences (Contributor, Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
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Description
Calcium is the only ion capable of triggering electrical and chemical reactions in cells which are part of essential biomolecular processes, such as gene transcription and ion flux. Calcium homeostasis, the control of concentration levels, is therefore crucial for the proper functioning of cells. For example, cardiomyocytes, the cells that

Calcium is the only ion capable of triggering electrical and chemical reactions in cells which are part of essential biomolecular processes, such as gene transcription and ion flux. Calcium homeostasis, the control of concentration levels, is therefore crucial for the proper functioning of cells. For example, cardiomyocytes, the cells that form cardiac muscle, rely on calcium transfer process to produce muscle contraction.
The purpose of this work is to study aspects of calcium homeostasis in the model organism Saccharomyces cerevisiae, common yeast. Using luminometric techniques, the response of the yeast was monitored against a set of changes in the environment calcium abundance. The results indicate a complex response as both increase and decreases of external calcium induce elevations in cytosolic calcium concentrations.
Calcium is transferred across compartments by means of channels. In Saccharomyces cerevisiae, many of them have been identified; Cch1p-Mid1p, Vcx1p, Pmc1p, Pmr1p, and Yvc1p. Their participation in calcium homeostasis is well established. Observations of cytosolic calcium increase after a hypertonic shock are mainly associated with influx of ions from the environment though the Cch1p-Mid1p. This process is generally considered as driven by calcium concentration gradients. However, recent studies have suggested that the plasma membrane channel, Cch1p-Mid1p, may possess more sophisticated regulation and sensory mechanisms. The results of our experiments support these ideas.
We carried out experiments that subjected yeast to multiple shocks: a hypertonic shock followed by either a second hypertonic shock, a hypotonic shock, or a yeast dilution pulse where the solution volume increases by the calcium concentration has only a small change. The cytosolic calcium concentration of a yeast population was monitored via luminometry.
The main result of this study is the observation of an unexpected response to the combination of hypertonic and hypotonic shocks. In this case it was observed that the cytosolic calcium concentration increased after both shocks. This indicates that cytosolic calcium increases are not solely driven by the presence of concentration gradients. The response after the hypotonic pulse arises from more complex mechanisms that may include sensor activity at the membrane channels and the release of calcium from internal storages.
ContributorsParker, Augustus Carrucciu (Co-author) / Mintz, David (Co-author) / Solis, Francisco (Thesis director) / Marshall, Pamela (Committee member) / School of Mathematical and Natural Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
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Description
Cellular and molecular biologists often perform cellular assays to obtain a better understanding of how cells work. However, in order to obtain a measurable response by the end of an experiment, the cells must reach an ideal cell confluency. Prior to conducting the cellular assays, range-finding experiments need to be

Cellular and molecular biologists often perform cellular assays to obtain a better understanding of how cells work. However, in order to obtain a measurable response by the end of an experiment, the cells must reach an ideal cell confluency. Prior to conducting the cellular assays, range-finding experiments need to be conducted to determine an initial plating density that will result in this ideal confluency, which can be costly. To help alleviate this common issue, a mathematical model was developed that describes the dynamics of the cell population used in these experiments. To develop the model, images of cells from different three-day experiments were analyzed in Photoshop®, giving a measure of cell count and confluency (the percentage of surface area covered by cells). The cell count data were then fitted into an exponential growth model and were correlated to the cell confluency to obtain a relationship between the two. The resulting mathematical model was then evaluated with data from an independent experiment. Overall, the exponential growth model provided a reasonable and robust prediction of the cell confluency, though improvements to the model can be made with a larger dataset. The approach used to develop this model can be adapted to generate similar models of different cell-lines, which will reduce the number of preliminary range-finding experiments. Reducing the number of these preliminary experiments can save valuable time and experimental resources needed to conduct studies using cellular assays.
ContributorsGuerrero, Victor Dominick (Co-author) / Guerrero, Victor (Co-author) / Watanabe, Karen (Thesis director) / Jurutka, Peter (Committee member) / School of Mathematical and Natural Sciences (Contributor, Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
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Description
A lab protocol was created in order to introduce arson evidence analysis to students. The procedures dictate a thorough introduction from evidence handling procedures to analysis of common accelerant mass spectrum. The objectives of the lab protocol included classifying and describing various pieces of arson evidence and common accelerants as

A lab protocol was created in order to introduce arson evidence analysis to students. The procedures dictate a thorough introduction from evidence handling procedures to analysis of common accelerant mass spectrum. The objectives of the lab protocol included classifying and describing various pieces of arson evidence and common accelerants as well as synthesizing information about accelerant composition to interpret GC-MS data output. This would allow the student to experience first-hand what the subsection of arson analysis has to offer in the field of forensic science which could help the student decide on more specialties to study later on. I was unable to run the lab protocol in a laboratory setting, therefore in the future I want to use the lab protocol and receive feedback in order to improve the protocol so the student is receiving the best possible learning outcomes. The experience of creating a lab protocol in forensic science gave myself a greater understanding of what goes on behind an academic learning procedure and more insight on arson evidence analysis.
Created2020-05
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Description
Capsaicin and dihydrocapsaicin account for 90% of capsaicinoids when it comes to the pungency of peppers. Capsaicin stability was investigated through a cooking and storage parameter where three different tests were done; cooking duration, cooking temperature, and storage stability. The concentration of capsaicinoids was quantified through gas chromatography-mass spectrometry where

Capsaicin and dihydrocapsaicin account for 90% of capsaicinoids when it comes to the pungency of peppers. Capsaicin stability was investigated through a cooking and storage parameter where three different tests were done; cooking duration, cooking temperature, and storage stability. The concentration of capsaicinoids was quantified through gas chromatography-mass spectrometry where those values were then used to determine the total Scoville heat units (SHU). Furthermore, half-life was determined by finding the decay rate during cooking and storage. Results showed that there was an increase in degradation of capsaicinoids concentration when peppers were cooked for a long period of time. Degradation rate increases with increasing temperatures as would be expected by the Arrhenius equation. Hence, if a maximum pungency is wanted, it is best to cook the least time as possible or add the peppers towards the end of the culinary technique. This would help by cooking the peppers for a short period of time while not being exposed to the high temperature long enough before significant degradation occurs. Lastly, the storage stability results interpreted that a maximum potency of the peppers can be retained in a freezer or refrigerator opposed to an open room temperature environment or exposure from the sun. Furthermore, the stability of peppers has a long shelf life with even that the worse storage condition's half-life value was 113.5 months (9.5 years). Thus, peppers do not need to be bought frequently because its potency will last for several years.
ContributorsBustamante, Krista Gisselle (Author) / Cahill, Thomas (Thesis director) / Sweat, Ken (Committee member) / Armendariz Guajardo, Jose (Committee member) / School of Mathematical and Natural Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2017-12
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Description
Vitamin D, Klotho, and FOXO3 have all been linked to have anti-aging and anti-cancerous effects as separate pathways. Specifically, mice with knockout Klotho in their genes have displayed signs of premature aging, humans who are vitamin D deficient have been shown to develop cardiovascular disease and cognitive impairments, and those

Vitamin D, Klotho, and FOXO3 have all been linked to have anti-aging and anti-cancerous effects as separate pathways. Specifically, mice with knockout Klotho in their genes have displayed signs of premature aging, humans who are vitamin D deficient have been shown to develop cardiovascular disease and cognitive impairments, and those who have displayed overexpression of FOXO3 have shown to have a longer lifespan. Here we took each pathway and attempted to formulate a feedback mechanism loop linking all three separate pathways. We propose that vitamin D levels modulate klotho activity, including the expression of the s-klotho and m-klotho isoforms. Moreover, the anti-oxidation transcription factor FOXO3 is also thought to participate in crosstalk with VDR signaling. Through the connection between 1,25D and Klotho, we probed at their interactions with FOXO3 signaling in kidney and colon cells, and proposed that vitamin D and klotho may reduce oxidative stress and suppress the onset of epithelial cancers through it effects on FOXO3. Results showed a strong support for the cooperation between FOXO3 and 1,25D to stimulate both superoxide dismutase (a FOXO3 response element) and XDR3/ROC (vitamin D response elements). This cooperation was mostly seen in embryonic kidney cells (HEK293) and not in the colon cancer cells (HCT116), which has led to the conclusion that vitamin D and FOXO3 cooperation mainly occurs in kidney tissue and/or in tissue that is not yet been overtaken by cancer. Differences in the Klotho isoforms were seen when measuring FOXO3 and vitamin D activity, but experiments manipulating other components will need to be conducted to further understand the function of Klotho in maintaining reactive oxygenated species levels.
ContributorsSandoval, Ruby (Author) / Jurutka, Peter (Thesis director) / Sandrin, Todd R. (Committee member) / Heck, Michael (Committee member) / School of Social and Behavioral Sciences (Contributor) / School of Mathematical and Natural Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
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Description
Partial differential equation (PDE) models are widely used for modeling processes in the physical sciences, economics, and sociology, but are otherwise new to the realm of social media. They allow researchers to construct a single spatiotemporal mathematical model to predict, in the case of this study, the level of information

Partial differential equation (PDE) models are widely used for modeling processes in the physical sciences, economics, and sociology, but are otherwise new to the realm of social media. They allow researchers to construct a single spatiotemporal mathematical model to predict, in the case of this study, the level of information saturation at particular points in space at specific times. Utilizing data from the popular social network Twitter, this study presents a preliminary work looking into the effects of aggregating spatial data on such a PDE model. In other literature, the source of analytical and statistical bias that results from arbitrary spatial aggregation is known as the modifiable areal unit problem (MAUP). We use a previously-studied dataset from the 2011 Egyptian revolution for simulation, and group data points using several distance metrics based on geographical location and geo-cultural similarity. This paper will attempt to show that a PDE model, necessarily dependent upon aggregating data, is subject to significant bias when said data are arbitrarily organized and grouped for simulation. We look primarily into the zoning problem, which amounts to maintaining a fixed number of regions located in different areas across the globe, but make note of the scale problem, an inherent issue in PDE modeling that results from aggregating data points into increasingly larger regions. From looking at specific values from each simulation, this study shows that such a model is not free from the MAUP and that consideration of how data are aggregated needs to be made for future studies. In addition, it also suggests that geo-political and geo-cultural spatial metrics generate better diffusive patterns for tweet propagation than do simple geographical proximity metrics.
ContributorsRaymond, Ross Edward Scott (Author) / Kwon, Kyounghee Hazel (Thesis director) / Gruber, Diane (Committee member) / School of Mathematical and Natural Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
Description
Desert ecosystems are one of the fastest urbanizing areas on the planet. This rapid shift has the potential to alter the abundances and species richness of herbivore and plant communities. Herbivores, for example, are expected to be more abundant in urban desert remnant parks located within cities due to anthropogenic

Desert ecosystems are one of the fastest urbanizing areas on the planet. This rapid shift has the potential to alter the abundances and species richness of herbivore and plant communities. Herbivores, for example, are expected to be more abundant in urban desert remnant parks located within cities due to anthropogenic activities that concentrate food resources and reduce native predator populations. Despite this assumption, previous research conducted around Phoenix has shown that top-down herbivory led to equally reduced plant biomass. It is unclear if this insignificant difference in herbivory at rural and urban sites is due to unaltered desert herbivore populations or altered activity levels that counteract abundance differences. Vertebrate herbivore populations were surveyed at four sites inside and four sites outside of the core of Phoenix during fall 2014 and spring 2015 in order to determine whether abundances and richness differ significantly between urban and rural sites. In order to survey species composition and abundance at these sites, 100 Sherman traps and 8 larger wire traps that are designed to attract and capture small vertebrates such as mice, rats, and squirrels, were set at each site for two consecutive trap nights. Results suggest that the commonly assumed effect of urbanization on herbivore abundances does not apply to small rodent herbivore populations in a desert city, as overall small rodent abundances were statistically similar regardless of location. Though a significant difference was not found for species richness, a significant difference between small rodent genera richness at these sites was observed.
ContributorsAlvarez Guevara, Jessica Noemi (Co-author) / Ball, Becky A. (Co-author, Thesis director) / Hall, Sharon J. (Co-author) / Bateman, Heather (Committee member) / School of Sustainability (Contributor) / School of Mathematical and Natural Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05