Matching Items (6)
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- All Subjects: Environmental science
- Creators: Polidoro, Beth
- Creators: Penton, Christopher
- Status: Published
Description
Sexually transmitted diseases like gonorrhea and chlamydia, standardly treated with antibiotics, produce over 1.2 million cases annually in the emergency department (Jenkins et al., 2013). To determine a need for antibiotics, hospital labs utilize bacterial cultures to isolate and identify possible pathogens. Unfortunately, this technique can take up to 72 hours, leading to several physicians presumptively treating patients based solely on history and physical presentation. With vague standards for diagnosis and a high percentage of asymptomatic carriers, several patients undergo two scenarios; over- or under-treatment. These two scenarios can lead to consequences like unnecessary exposure to antibiotics and development of secondary conditions (for example: pelvic inflammatory disease, infertility, etc.). This presents a need for a laboratory technique that can provide reliable results in an efficient matter. The viability of DNA-based chip targeted for C. trachomatis, N. gonorrhoeae, and other pathogens of interest were evaluated. The DNA-based chip presented several advantages as it can be easily integrated as a routine test given the process is already well-known, is customizable and able to target multiple pathogens within a single test and has the potential to return results within a few hours as opposed to days. As such, implementation of a DNA-based chip as a diagnostic tool is a timely and potentially impactful investigation.
ContributorsCharoenmins, Patherica (Author) / Penton, Christopher (Thesis director) / Moore, Marianne (Committee member) / College of Integrative Sciences and Arts (Contributor) / Barrett, The Honors College (Contributor)
Created2016-12
Description
Precision agriculture (PA) integrating information technology arouses broad interests and has been extensively studied to increase crop production and quality. Sensor probe technology, as one of the PA technologies, provides people with accurate real-time data, which has become an essential part of precision agriculture. Herein a novel microbial sensor probe (MiProbE) is applied to monitor and study the growth of tomatoes (Solanum lycopersicum L.) in real-time at germination and seedling stages. The result showed the raw Miprobe signals present day/night cycles. Alginate-coated probes effectively avoided signal response failure and were more sensitive to the treatments than uncoated probes. The probe signals from successfully germinated tomato seeds and non-germinated seeds were different, and the signal curve of the probe was closely related to the growth conditions of tomato seedlings. Specifically, the rising period of the probe signals coincided with the normal growth period of tomato seedlings. All probes exhibited sudden increases in signal strength after nutrient treatments; however, subsequent probe signals behaved differently: algae extract-treated probe signals maintained a high strength after the treatments; chemical fertilizer-treated probe signals decreased earlier after the treatments; chemical fertilizers and algae extract-treated probe signals also maintained a higher strength after the treatments. Moreover, the relationship between ash-free dry weight and the signal curve indicated that the signal strength positively correlates with the dry weight, although other biological activities can affect the probe signal at the same time. Further study is still needed to investigate the relationship between plant biomass and Miprobe signal.
ContributorsQi, Deyang (Author) / Weiss, Taylor (Thesis advisor) / Penton, Christopher (Committee member) / Park, Yujin (Committee member) / Arizona State University (Publisher)
Created2021
Description
Advanced technology has increased access to Antarctica; consequently, there has been an increase in research and tourism. The production of the new technology and the increased number of individuals visiting can increase the presence of persistent organic pollutants and microplastic within Antarctic soil. Studies have focused primarily on identifying these pollutants in high human impact areas with perhaps an assumption that low human impact areas would have lower concentrations of pollutants. The object of this paper, therefore, was to test the hypothesis that higher concentrations of persistent organic pollutants and microplastic are found in soils collected near research stations and tourist areas, as opposed to sites that are further from stations and have less direct human impact. Soil samples were collected along a 1,500 km transect of the Scotia Arch and Antarctic Peninsula from three high human impact sites and three low human impact sites to compare the concentration of contaminates identified within the soil. The presence and quantities of microplastic were identified using Nile Red and fluorescence microscopy, while gas chromatography-mass spectrometry was used to detect polychlorinated biphenyls, pesticides, polycyclic aromatic hydrocarbons, n-alkane, and phthalates. Although varying contaminate concentration levels were found at all six sights, counter to the hypothesis, there were no clear patterns of increasing pollutants with increasing human activities. These findings could imply that global sources of pollutants can increase local pollutants indicating the best way to solve any pollution problem is through a global lens.
ContributorsCarroll, Kenneth Charles (Author) / Polidoro, Beth (Thesis advisor) / Kinzig, Ann (Thesis advisor) / Ball, Becky (Committee member) / Arizona State University (Publisher)
Created2022
Description
Marine ecosystems are currently being impacted by various threats; however, quantification of the impacts of known threats and the population status of species are often conducted at different scales, depending upon stakeholder needs. Global-scale species assessments can mask the impact of local or regional threats within the context of global conservation priorities even as conservation policies are generally implemented at the local or regional scale. This work aims to identify the regional threats currently impacting species present within the Gulf of Mexico as well as the current polices addressing those threats. Species currently impacted by threats were used to build an ecosystem model to estimate food web dynamics in the Gulf of Mexico. This model is the first of its kind to incorporate data from more than 1500 species occurring in the Gulf including all marine bony shorefishes, marine reptiles, complete clades of select marine invertebrates, marine birds, marine mammals, and chondrichthyans. Comprehensive analyses of these groups are important for an improved understanding of the functioning of the Gulf of Mexico food web and the impact of identified threats on food web dynamics. The identification of current threats and food web dynamics will help to inform conservation policy moving forward. Properly framed conservation efforts are more likely to be widely accepted and successful when there is an improved understanding on how policies can impact stakeholders both economically and through changing practices. Finally, an investigation of the legal frameworks currently recognized in the Gulf of Mexico was done to build an example tri-national framework between the United States, Mexico, and Cuba focusing on current conservation gaps allowing for specific regional conservation concerns to be addressed.
ContributorsStrongin, Kyle (Author) / Polidoro, Beth (Thesis advisor) / Saul, Steven (Committee member) / Gerber, Leah (Committee member) / Arizona State University (Publisher)
Created2021
Description
Stressors to marine environments are predicted to increase and affect the well-being of marine ecosystems and coastal communities. Marine protected areas (MPAs) are one most widely implemented interventions for marine stressors. Despite the implementation of thousands of protected areas worldwide, people are still striving to understand their dynamics as they vary in their efficacy and many MPAs have not met their objectives. Additionally, those that have often fail to protect the ecosystem services and cultural values necessary for human community health. Thus, research has expanded to include analyses of the human and social dimensions that may limit their effectiveness. This dissertation explores the role of community engagement in marine protected areas and perceptions of environmental changes in coastal communities. Currently, existing research on the roles of community engagement in marine conservation interventions is limited, particularly in the island-states of the Caribbean region. This dissertation contains a review of the literature to understand the nuances of community engagement in relation to MPAs. Through the review, it was determined that primary forms of engagement are interviews and surveys, and respondents primarily included businesses, community members, fishers, and resource users. To better understand the perceptions and practices on-the-ground, key informants were interviewed across the Caribbean. There are strong desires to conduct community engagement for innumerable benefits, but there are barriers that some participants have overcome. Sharing information between MPA sites offers an opportunity to effectively engage community members. For the local case study, Charlotteville, Trinidad and Tobago, a small, coastal fishing town in the northeast region of Tobago was selected to understand the role of perceptions of environmental changes. There were strong ties of environmental and social changes, with an emphasis on the impacts of environmental stressors to human health. The heterogeneity and diversity of responses in this chapter highlight the need to consider who is engaged in community engagement activities.
ContributorsBernard, Miranda Lynn (Author) / Gerber, Leah (Thesis advisor) / Buzinde, Christine (Committee member) / Schoon, Michael (Committee member) / Kittinger, Jack (Committee member) / Cheng, Samantha (Committee member) / Arizona State University (Publisher)
Created2021
Description
There is an estimated five trillion pieces of plastic in the global ocean, with 4.8 to 12.7 million metric tons entering the ocean annually. Much of the plastic in the ocean is in the form of microplastics, or plastic particles <5mm in size. Microplastics enter the marine environment as primary or secondary microplastics; primary microplastics are pre-manufactured micro-sized particles, such as microbeads used in cosmetics, while secondary microplastics form from the degradation of larger plastic objects, such water bottles. Once in the ocean, plastics are readily colonized by a consortium of prokaryotic and eukaryotic organisms, which form dense biofilms on the plastic; this biofilm is termed the “plastisphere”. Despite growing concerns about the ecological impact of microplastics and their respective plastispheres on the marine environment, there is little consensus about the factors that shape the plastisphere on environmentally relevant secondary microplastics. The goal of my dissertation is to comprehensively analyze the role of plastic polymer type, incubation time, and geographic location on shaping plastisphere communities attached to secondary microplastics. I investigated the plastisphere of six chemically distinct plastic polymer types obtained from common household consumer products that were incubated in the coastal Caribbean (Bocas del Toro, Panama) and coastal Pacific (San Diego, CA) oceans. Genotyping using 16S and 18S rRNA gene amplification and next-generation Illumina sequencing was employed to identify bacterial and eukaryotic communities on the polymer surfaces. Statistical analyses show that there were no polymer-specific assemblages for prokaryotes or eukaryotes, but rather a microbial core community that was shared among plastic types. I also found that rare hydrocarbon degrading bacteria may be specific to certain chemical properties of the microplastics. Statistical comparisons of the communities across both sites showed that prokaryotic plastispheres were shaped primarily by incubation time and geographic location. Finally, I assessed the impact of biofilms on microplastic degradation and deposition and conclude that biofilms enhance microplastic sinking of negatively buoyant particles and reduce microplastic degradation. The results of my dissertation increases understanding of the factors that shape the plastisphere and how these communities ultimately determine the fate of microplastics in the marine environment.
ContributorsDudek, Kassandra Lynn (Author) / Neuer, Susanne (Thesis advisor) / Polidoro, Beth (Committee member) / Garcia-Pichel, Ferran (Committee member) / Cao, Huansheng (Committee member) / Arizona State University (Publisher)
Created2021