Matching Items (159)
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 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.
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
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 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.
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
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 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
Description
The process of communicating science between the general public and scientific community has been marked by several challenges in the modern setting. Namely, scientists’ trepidation toward misinterpretation, jeopardization of professional reputability, and perception of two distinct arenas of communication has led to the perpetuation of the deficit model of communication. This model is exceptionally limiting as it effectively removes the scientists from the public sphere and can have devastating societal repercussions. The dialogue model of communication is a much more effective communicative model for the modern setting but has been met with resistance in its adoption. As communication as a whole is grounded in multiple foundational disciplines of psychology, philosophy, linguistics, and other fields, it would be apparent that the adoption of the principles of polymathy would serve to better prepare scientists to engage in mass communication with the public. As polymathy is a lifelong pursuit, the implementation of narrative training into collegiate undergraduate science curriculum would serve as a particularly potent beginning. That is, narrative's ability to reach near-universal audiences, enhance the recall and comprehension of complex subject matter, and forge an empathetic connection essential to effective communication is uniquely suited in ensuring a more effective communicative dynamic between the scientific community and the general public. As such, this thesis serves to advocate the adoption of narrative-based communicative training into undergraduate science curriculum not as separate courses, but rather as direct incorporation. This would serve to both revitalize polymathy in the modern age and prepare the next generation of scientists to be better equipped for the public dialogue.
ContributorsCoker, Keaton M (Author) / Ramsey, Ramsey E. (Thesis director) / Wentzel, Bonnie (Committee member) / School of Social and Behavioral Sciences (Contributor) / School of Mathematical and Natural Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
Description
Vitamin D3 (cholecalciferol) is an essential micronutrient that plays a key role in developmental growth and lifespan in mammals. However, few studies have shown how vitamin D3 plays its vital functions in arthropods. Here, we examined the effects of full (13.3 IU/mL) and half dose (6.65 IU/mL) vitamin D3 on the growth and lifespan of Drosophila melanogaster. Vitamin B12 is another micronutrient that shows decreases absorption in elderly patients and might be linked to symptoms associated with aging rather than lifespan, but again, the effects of vitamin B12 supplementation in arthropods is poorly characterized. Results showed that both full and half doses of vitamin D3 and B12 do not significantly alter the timing of pupariation or adult eclosion. Similarly, the mortality rate of adult D. melanogaster exposed to vitamin B12 or higher doses of vitamin D3 was not significantly decreased or increased. However, a low dose of vitamin D3 did significantly lower the mortality rate of D. melanogaster. The genetic composition of Drosophila for vitamin B12 and D metabolism showed similarities in humans. However, there are no biological evidences if these genes are functional thus, this may explain the results of this study.
ContributorsRebonza, Edzel May Suico (Author) / Hackney Price, Jennifer (Thesis director) / Jurutka, Peter (Committee member) / School of Mathematical and Natural Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
Description
The topic of elder abuse is relatively unknown and not talked about among the general public. Traditionally, society values one’s life the younger that person is on the grounds that the younger person has most likely not experienced life to the fullest extent as much as the older person has. The point of bringing up this way of thinking is not to refute it but to point out that a product of this societal mindset is that the elderly population is often forgotten about or placed on a lower priority level when considering medical and safety issues. This is a major factor that contributes to the vulnerability of older persons, who often must give up their autonomy due to the aging process and learn to live while being dependent on a caretaker. Elders are often in situations where they are isolated from the rest of the world and place their trust in their caretakers to help them live out the rest of their lives. Unfortunately, the process of aging and becoming dependent opens up the opportunity for this vulnerable age group to be taken advantage of and abused. The National Council on Aging reported that about 1 in 10 elderly Americans that are 60 years old or older have been abused in some capacity, and only about 1 in 14 of these cases are reported (NCOA, 2020). As the world population ages, these statistics face the risk of getting worse and exposing more elders to abuse while less and less abuse cases are reported to authorities. This presents the opportunity for elder abuse research to guide healthcare institutions that are related to caring for the elderly on how to care for and prevent elder abuse from occurring; however, this research is quite limited in comparison to the research, treatments, and prevention programs developed for other types of domestic abuse. The aim of this paper is to create an overall understanding of elder abuse as a whole and get a sense of the state of elder abuse so recommendations can be made on how to proceed in bettering the current issues elder abuse faces.
ContributorsCampbell, Alexander Daza (Author) / Kobojek, Kimberly (Thesis director) / Bolhofner, Katelyn (Committee member) / School of Mathematical and Natural Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
Description
A student’s sense of belonging at a higher education institution can have a profound impact on their ability to persist through college and complete a degree program. First-year students enrolled in NEW 101 classes at Arizona State University’s (ASU’S) West campus were evaluated to determine if the Solera Experience, a program designed to help first-year students integrate into the ASU community, had an impact on first-year students’ sense of belonging at ASU. Although the Solera Experience was not found to have a large impact on students’ sense of belonging, it is worth noting that a majority of the first-year students felt like they belong at ASU. Additionally, a student’s short-term and long-term belief in their own academic success did influence their perception of belonging at ASU, which suggests, overall, that the programs ASU has in place to establish sense of belonging seem to be effective.
ContributorsMurray, Abigail (Author) / Gruber, Diane (Thesis director) / Gordon, Karen (Committee member) / Aska, Cassandra (Committee member) / School of Mathematical and Natural Sciences (Contributor) / School of Social and Behavioral Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
Description
Chemiluminescent reagents, such as BlueStar® forensic reagent, are used during crime scene investigations to detect latent bloodstains as they react with the iron in blood to produce bright chemiluminescence. There are several substances that cause false positives with BlueStar® reagent, including plant peroxidases and certain metal compounds. These false positive substances are commonly seen in cosmetic products. The widespread availability and popularity of cosmetics makes it possible that false positive substances may be encountered at crime scenes and could potentially interfere with investigations. The cosmetic products chosen for this study included two of the following types of products at different price points: foundation, primer, moisturizer, cleanser, and setting powder. The ten cosmetic products were tested with BlueStar® forensic reagent in two rounds of testing on multiple surface types to mimic different ways investigators may encounter the products at crime scenes. The results of the tests were overall negative as the products did not produce any chemiluminescence, indicating that the products do not cause false positives with the BlueStar® forensic reagent and are not concern for investigators. As a majority of the products contain ingredients known to cause false positives with BlueStar®, the completely negative results raised several questions. More exploration of the interaction between cosmetic products and BlueStar® reagents needs to occur in order to clarify and confirm if cosmetics pose a risk to crime scene investigators.
ContributorsMaley, Samantha Bree (Author) / Kobojek, Kimberly (Thesis director) / Cahill, Thomas (Committee member) / School of Mathematical and Natural Sciences (Contributor) / School of Criminology and Criminal Justice (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
Description
Undergraduate students taking Anatomy and Physiology may struggle with information overload due to constant memorization. The solution is to present the anatomical material in a more integrative manner. Traditional learning in the human anatomy labs requires students to be presented with the skin, bones, joints, and muscle systems throughout the semester. However, in the Human Anatomy and Physiology courses (BIO 201), students only spend 2.5 hours for the lab session in one or two weeks for each system. The traditional style used today is constructed systematically, but it does not combine the other systems and functions with it once presented to the students. As a result, the new approach will integrate the structures and functions of each system with the current one that is being introduced. The new approach is SiMoJi-B: Skin, Muscles, Joints, and Bones. SiMoJi-B will teach students the Skin, Muscles, Joints, and Bones systems following anatomical regions of the body each week. All systems are integrated using a layer visualization from the outer to the deepest layer. The integration is supported with human donor dissections. The integrative sequence will allow students to learn anatomy in a more interactive and dynamic way.
ContributorsKaroubi, Susan (Author) / Cevallos, Manuel (Thesis director) / Ferry, Lara (Committee member) / School of Mathematical and Natural Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
Since its isolation from a rhesus monkey in the Zika forest of Uganda in 1947, Zika virus (ZIKV) has spread into many parts of the world, causing major epidemics, notably in the Americas and some parts of Europe and Asia. The flavivirus ZIKV is primarily transmitted to humans via the bite of infectious adult female Aedes mosquitoes. In the absence of effective treatment or a safe and effective vaccine against the disease, control efforts are focused on effective vector management to reduce the mosquito population and limit human exposure to mosquito bites. The work in this thesis is based on the use of a mathematical model for gaining insight into the transmission dynamics of ZIKV in a population. The model, which takes the form of a deterministic system of nonlinear differential equations, is rigorously analyzed to gain insight into its basic qualitative features. In particular, it is shown that the disease-free equilibrium of the model is locally-asymptotically stable whenever a certain epidemiological quantity (known as the reproduction number, denoted by R0) is less than unity. The epidemiological implication of this result is that a small influx of ZIKV-infected individuals or vectors into the community will not generate a large outbreak if the anti-ZIKV control strategy (or strategies) adopted by the community can reduce and maintain R0 to a value less than unity. Numerical simulations of the model, using data relevant to ZIKV transmission dynamics in Puerto Rico, shows that a control strategy that solely focuses on killing immature mosquitoes (using highly efficacious larvicides) can lead to the elimination of ZIKV if the larvicide coverage (i.e., proportion of breeding sites treated with larvicides) is high enough (over 90%). Such elimination is also feasible using a control strategy that solely focuses on the use of insect repellents (as a means of personal protection against mosquito bites) if the coverage level of the insect repellent usage in the community is high enough (at least 70%). However, it is also shown that although the use of adulticides (i.e., using insecticides to kill adult mosquitoes) can reduce the reproduction number (hence, disease burden), it fails to reduce it to a value less than unity, regardless of coverage level. Thus, unlike with the use of larvicide-only or repellent-only strategies, the population-wide implementation of an adulticide-only strategy is unable to lead to ZIKV elimination. Finally, it is shown that the combined (integrated pest management) strategy, based on using all three aforementioned strategies, is the most effective approach for combatting ZIKV in the population. In particular, it is shown that even a moderately-effective level of this strategy, which entails using only 50% coverage of both larvicides and adulticides, together with about 45% coverage for a repellent strategy, will lead to ZIKV elimination. This moderately-effective combined strategy seems attainable in Puerto Rico.
ContributorsUrcuyo, Javier (Author) / Gumel, Abba (Thesis director) / Hackney Price, Jennifer (Committee member) / School of Mathematical and Natural Sciences (Contributor, Contributor) / Barrett, The Honors College (Contributor)
Created2019-05