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With global warming becoming a more serious problem and mankind's alarming dependency on fossil fuels, the need for a sustainable and environmentally friendly fuel source is becoming more important. Biofuels produced from photosynthetic microorganisms like algae or cyanobacteria offer a carbon neutral replacement for petroleum fuel sources; however, with the technology and information available today, the amount of biomass that would need to be produced is not economically feasible. In this work, I examined a possible factor impacting the growth of a model cyanobacterium, Synechocystis sp. PCC6803, which is heterotrophic bacteria communities accompanying the cyanobacteria. I experimented with three variables: the type of heterotrophic bacteria strain, the initial concentration of heterotrophic bacteria, and the addition of a carbon source (glucose) to the culture. With experimental information, I identified if given conditions would increase Synechocystis growth and thus increase the yield of biomass. I found that under non-limiting growth conditions, heterotrophic bacteria do not significantly affect the growth of Synechocystis or the corresponding biomass yield. The initial concentration of heterotrophic bacteria and the added glucose also did not affect the growth of Synechocystis. I did see some nutrient recycling from the heterotrophic bacteria as the phosphate levels in the growth medium were depleted, which was apparent from prolonged growth phase and higher levels of reactive phosphate in the media.
ContributorsCahill, Brendan Robert (Author) / Rittmann, Bruce (Thesis director) / Krajmalnik-Brown, Rosa (Committee member) / W. P. Carey School of Business (Contributor) / Chemical Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2015-12
Description
Inhibition by ammonium at concentrations above 1000 mgN/L is known to harm the methanogenesis phase of anaerobic digestion. We anaerobically digested swine waste and achieved steady state COD-removal efficiency of around 52% with no fatty-acid or H[subscript 2] accumulation. As the anaerobic microbial community adapted to the gradual increase of total ammonia-N (NH[subscript 3]-N) from 890 ± 295 to 2040 ± 30 mg/L, the Bacterial and Archaeal communities became less diverse. Phylotypes most closely related to hydrogenotrophic Methanoculleus (36.4%) and Methanobrevibacter (11.6%), along with acetoclastic Methanosaeta (29.3%), became the most abundant Archaeal sequences during acclimation. This was accompanied by a sharp increase in the relative abundances of phylotypes most closely related to acetogens and fatty-acid producers (Clostridium, Coprococcus, and Sphaerochaeta) and syntrophic fatty-acid Bacteria (Syntrophomonas, Clostridium, Clostridiaceae species, and Cloacamonaceae species) that have metabolic capabilities for butyrate and propionate fermentation, as well as for reverse acetogenesis. Our results provide evidence countering a prevailing theory that acetoclastic methanogens are selectively inhibited when the total ammonia-N concentration is greater than ~1000 mgN/L. Instead, acetoclastic and hydrogenotrophic methanogens coexisted in the presence of total ammonia-N of ~2000 mgN/L by establishing syntrophic relationships with fatty-acid fermenters, as well as homoacetogens able to carry out forward and reverse acetogenesis.
ContributorsEsquivel Elizondo, Sofia (Author) / Parameswaran, Prathap (Author) / Delgado, Anca (Author) / Maldonado, Juan (Author) / Rittmann, Bruce (Author) / Krajmalnik-Brown, Rosa (Author) / Biodesign Institute (Contributor) / Swette Center for Environmental Biotechnology (Contributor) / Ira A. Fulton Schools of Engineering (Contributor) / School of Sustainable Engineering and the Built Environment (Contributor)
Created2016-08-11
Description
We studied the microbial community structure of pilot two-stage membrane biofilm reactors (MBfRs) designed to reduce nitrate (NO[subscript 3]–) and perchlorate (ClO[subscript 4]–) in contaminated groundwater. The groundwater also contained oxygen (O[subscript 2]) and sulfate (SO[2 over 4]–), which became important electron sinks that affected the NO[subscript 3]– and ClO[subscript 4]– removal rates. Using pyrosequencing, we elucidated how important phylotypes of each “primary” microbial group, i.e., denitrifying bacteria (DB), perchlorate-reducing bacteria (PRB), and sulfate-reducing bacteria (SRB), responded to changes in electron-acceptor loading. UniFrac, principal coordinate analysis (PCoA), and diversity analyses documented that the microbial community of biofilms sampled when the MBfRs had a high acceptor loading were phylogenetically distant from and less diverse than the microbial community of biofilm samples with lower acceptor loadings. Diminished acceptor loading led to SO[2 over 4]– reduction in the lag MBfR, which allowed Desulfovibrionales (an SRB) and Thiothrichales (sulfur-oxidizers) to thrive through S cycling. As a result of this cooperative relationship, they competed effectively with DB/PRB phylotypes such as Xanthomonadales and Rhodobacterales. Thus, pyrosequencing illustrated that while DB, PRB, and SRB responded predictably to changes in acceptor loading, a decrease in total acceptor loading led to important shifts within the “primary” groups, the onset of other members (e.g., Thiothrichales), and overall greater diversity.
ContributorsOntiveros-Valencia, Aura (Author) / Tang, Youneng (Author) / Zhao, Heping (Author) / Friese, David (Author) / Overstreet, Ryan (Author) / Smith, Jennifer (Author) / Evans, Patrick (Author) / Rittmann, Bruce (Author) / Krajmalnik-Brown, Rosa (Author) / Biodesign Institute (Contributor) / Swette Center for Environmental Biotechnology (Contributor) / Julie Ann Wrigley Global Institute of Sustainability (Contributor) / School of Sustainability (Contributor)
Created2014-07-01
Description
The main purpose of this investigation is to determine the intensity, economic costs, and potential solutions to HIV/AIDS stigma in the United States and Tanzania. In order to accomplish this goal, a literature review was conducted, and an economic model was created to determine how HIV/AIDS treatment deterrence manifests and affects these countries. The results of the economic model suggested that Tanzania suffers greater economic loss due to HIV treatment deterrence than the United States, however, both countries lose a significant portion of GDP due to HIV treatment deterrence. Stigma materializes differently in each country based on a variety of sociocultural factors. These include the demographic groups most affected, the perception of those living with HIV, and how sexually transmitted infections are perceived within communities. The solutions to HIV stigma must be tailored to the country, culture, and context that it arises for interventions to be effective. To further prevent HIV/AIDS stigma and its economic consequences, the etiology of stigma and how it presents in different communities must be understood.
ContributorsSangha, Pooja (Co-author) / Hopewell, Sophia (Co-author) / Baldwin, Marjorie (Thesis director) / Hruschka, Daniel (Committee member) / Department of Psychology (Contributor) / Department of Economics (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
This paper explores the impacts of dam-induced displacement on the health of populations. By the start of the 21st century, an estimated 40-80 million people worldwide were forced to resettle due to the construction of large dams. The process of displacement and resettlement is connected to numerous social impacts on communities such as decreases in household income, natural resources, and social connectivity, but less seems to be known about specific health impacts. Analyzing literature in a formal review allowed for increased understanding about what information already exists in published research regarding the connections between dams, displacement, and health. Some negative health impacts as a result of forced displacement were identified, including increases in infectious disease transmission, depression, and mortality rates as well as losses of food and water sources. However, the small amount of cases found in the literature review when compared to the massive scale of dam development worldwide indicates a gap in knowledge in the dam industry and research field specifically about the health of the vast majority of populations forcibly displaced by dams. Health impacts must be considered and systematically studied in dam projects involving displacement to fully understand the needs of resettled populations and move towards equitable processes in development projects worldwide.
ContributorsWalker, Erika (Author) / Hruschka, Daniel (Thesis director) / Brian, Jennifer (Committee member) / Drake, Alexandria (Committee member) / School of Human Evolution & Social Change (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
Description
In Western medicine, the hard sciences have generally been understood as the sole guiding force in patient care and treatment. However, both history and the present day suggest another strong influence on Western medicine: folklore. The term folklore can easily be dismissed as a term representing beliefs and stories of the past, but its relevance transcends time and continues to impact people daily. It “involves values, traditions, ways of thinking and behaving. It’s about art. It’s about people and the way people learn. It helps us learn who we are and how to make meaning in the world around us” (Sims & Stephens, 2011, pp. 1-2). With its wide range of influence, folklore exists as the umbrella term encompassing several categories. Folk beliefs are one of these categories and can develop from “observation, memory, testimony or inference” (Hutton, 1942, p. 83). Given that each of these forms are subject to some sort of error, folk beliefs become “a jumble of the true and the erroneous” (p. 84). Similarly, contemporary legends are narratives that often combine the physical and supernatural world to explain nuances or uncertainty present in the relevant experiences of a people. Folk beliefs can result in the formation of contemporary legends and they can also stem from contemporary legends. These two categories are often associated with subjects that promote fear and uncertainty, and thus play an essential role in navigating folklore’s application to biomedicine. This paper explores the historical and modern effects that folklore has had on two separate maladies: Hansen’s Disease (leprosy) and Major Depressive Disorder (depression). While these conditions do not resemble each other in physical presentations, Hansen’s Disease and Major Depressive Disorder patients both have faced and continue to face discrimination. Andrea Wiley and John Allen’s three-part definition of a malady: society’s perception (sickness), the individual’s experience (illness), and medical professionals’ diagnosis and treatment (disease); was utilized as a tool for analyzing the application of folklore to modern medicine. The way that a society views a particular malady often dictates the sick role expected of a diagnosed individual. Additionally, the public’s view can directly affect medical professionals’ understanding of a malady. This then can drastically shape a patient’s diagnosis, treatment, and prognosis. This anthropological analysis acts as an interdisciplinary bridge between medicine and the humanities.
ContributorsPeake, Ashley E (Co-author) / Peake, Ashley (Co-author) / Ellis, Lawrence (Thesis director) / Hoyt, Heather (Committee member) / Hruschka, Daniel (Committee member) / School of Molecular Sciences (Contributor) / Department of English (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
Description
Menstruation - a stigmatized topic and a social taboo- has led to a lack of menstrual hygiene awareness and improper practices impacting women’s health adversely over generations in India. Akshara aims to increase menstrual hygiene education and reduce stigma in India. A creative children’s illustrated book, and interactive workshop curriculum about menstruation were designed and published in Hindi and English. Menstrual hygiene workshops, utilizing the designed tools, were conducted in Delhi and Ghaziabad, India to over 230 students through NGO partnerships in December 2018. The response to the menstrual hygiene and stigma workshops was overwhelmingly positive, and a significant increase in the knowledge and awareness survey scores was observed after the curriculum teachings and classroom discussions. This evaluation highlights and provides a potential solution path to eradicate the root cause of the menstruation stigma in underprivileged women through education and open conversations on the topic starting at a pivotal young age. The main aim of the workshop was to help eradicate the stigma associated with menstruation and menstrual health in India through education.
ContributorsBhalla, Jahnavi (Co-author) / Dani, Advika (Co-author) / Schuster, Roseanne (Thesis director) / Hruschka, Daniel (Thesis director) / School of Molecular Sciences (Contributor) / School of Human Evolution & Social Change (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
More than 40% of all U.S. opioid overdose deaths in 2016 involved a prescription opioid, with more than 46 people dying every day from overdoses involving prescription opioids, (CDC, 2017). Over the years, lawmakers have implemented policies and laws to address the opioid epidemic, and many of these vary from state to state. This study will lay out the basic guidelines of common pieces of legislation. It also examines relationships between 6 state-specific prescribing or preventative laws and associated changes in opioid-related deaths using a longitudinal cross-state study design (2007-2015). Specifically, it uses a linear regression to examine changes in state-specific rates of opioid-related deaths after implementation of specific policies, and whether states implementing these policies saw smaller increases than states without these policies. Initial key findings of this study show that three policies have a statistically significant association with opioid related overdose deaths are—Good Samaritan Laws, Standing Order Laws, and Naloxone Liability Laws. Paradoxically, all three policies correlated with an increase in opioid overdose deaths between 2007 and 2016. However, after correcting for the potential spurious relationship between state-specific timing of policy implementation and death rates, two policies have a statistically significant association (alpha <0.05) with opioid overdose death rates. First, the Naloxone Liability Laws were significantly associated with changes in opioid-related deaths and was correlated with a 0.33 log increase in opioid overdose death rates, or a 29% increase. This equates to about 1.39 more deaths per year per 100,000 people. Second, the legislation that allows for 3rd Party Naloxone prescriptions correlated with a 0.33 log decrease in opioid overdose death rates, or a 29% decrease. This equates to 1.39 fewer deaths per year per 100,000 people.
ContributorsDavis, Joshua Alan (Author) / Hruschka, Daniel (Thesis director) / Gaughan, Monica (Committee member) / School of Human Evolution & Social Change (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
The gastrointestinal (GI) tract is home to a complex and diverse microbial ecosystem that contributes to health or disease in many aspects. While bacterial species are the majority in the GI tract, their cohabitants, fungal species, should not be forgotten. Children with autism spectrum disorder (ASD) often suffer from GI disorders and associated symptoms, implying a role the bacterial and fungal gut microbiota play in maintaining human health. The irregularities in GI symptoms can negatively affect the overall quality of life or even worsen behavioral symptoms the children present. Even with the increase in the availability of next-generation sequencing technologies, the composition and diversities of fungal microbiotas are understudied, especially in the context of ASD. We therefore aimed to investigate the gut mycobiota of 36 neurotypical children and 38 children with ASD. We obtained stool samples from all participants, as well as autism severity and GI symptom scores to help us understand the effect the mycobiome has on these symptoms. By targeting the fungal internal transcribed spacer (ITS) and bacterial 16S rRNA V4 regions, we obtained fungal and bacterial amplicon sequences, from which we investigated the diversities, composition, and potential link between two different ecological clades. From fungal amplicon sequencing results, we observed a significant decrease in the observed fungal OTUs in children with ASD, implying a lack of potentially beneficial fungi in ASD subjects. We performed Bray-Curtis principal coordinates analysis and observed significant differences in fungal microbiota composition between the two groups. Taxonomic analysis showed higher relative abundances of Candida , Pichia, Penicillium , and Exophiala in ASD subjects, yet due to a large dispersion of data, the differences were not statistically significant. Interestingly, we observed a bimodal distribution of Candida abundances within children with ASD. Candida's relative abundance was not significantly correlated with GI scores, but children with high Candida relative abundances presented significantly higher Autism Treatment Evaluation Checklist (ATEC) scores, suggesting a role of Candida on ASD behavioral symptoms. Regarding the bacterial gut microbiota, we found marginally lower observed OTUs and significantly lower relative abundance of Prevotella in the ASD group, which was consistent with previous studies. Taken together, we demonstrated that autism is closely linked with a distinct gut mycobiota, characterized by a loss of fungal and bacterial diversity and an altered fungal and bacterial composition.
ContributorsPatel, Jigar (Author) / Krajmalnik-Brown, Rosa (Thesis director) / Kang, Dae Wook (Committee member) / Adams, James (Committee member) / School of Molecular Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
The effect of an anaerobic reductive environment produced by the oxidation of zero valent iron (ZVI) on the microbial reductive dechlorination of trichloroethylene and its applicability to in-situ bioremediation processes was investigated using microcosms and soil column studies. I learned that microbial dechlorination requires a highly reductive environment, as represented by negative values for oxidation-reduction potential (ORP), which can be maintained through the addition of reducing agents such as ZVI, or to a lesser extent, the fermentation of added substrates such as lactate. Microcosm conditions represented distance from an in-situ treatment injection well and contained different types of iron species and dechlorinating bioaugmentation cultures. Diminishing efficacy of microbial reductive dechlorination along a gradient away from the injection zone was observed, characterized by increasing ORP and decreasing pH. Results also suggested that the use of particular biostimulation substrates is key to prioritizing the dechlorination reaction against competing microbial and abiotic processes by supplying electrons needed for microbial dechlorination.
ContributorsMouti, Aatikah (Author) / Krajmalnik-Brown, Rosa (Thesis director) / Delgado, Anca (Committee member) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2017-12