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Description
The growth rate hypothesis (GRH) proposes that higher growth rate (the rate of change in biomass per unit biomass, μ) is associated with higher P concentration and lower C∶P and N∶P ratios. However, the applicability of the GRH to vascular plants is not well-studied and few studies have been done on belowground biomass. Here we showed that, for aboveground, belowground and total biomass of three study species, μ was positively correlated with N∶C under N limitation and positively correlated with P∶C under P limitation. However, the N∶P ratio was a unimodal function of μ, increasing for small values of μ, reaching a maximum, and then decreasing. The range of variations in μ was positively correlated with variation in C∶N∶P stoichiometry. Furthermore, μ and C∶N∶P ranges for aboveground biomass were negatively correlated with those for belowground. Our results confirm the well-known association of growth rate with tissue concentration of the limiting nutrient and provide empirical support for recent theoretical formulations.
ContributorsYu, Qiang (Author) / Wu, Honghui (Author) / He, Nianpeng (Author) / Lu, Xiaotao (Author) / Wang, Zhiping (Author) / Elser, James (Author) / Wu, Jianguo (Author) / Han, Xingguo (Author) / College of Liberal Arts and Sciences (Contributor) / School of Life Sciences (Contributor) / Julie Ann Wrigley Global Institute of Sustainability (Contributor) / School of Sustainability (Contributor)
Created2012-03-13
Grasshoppers Regulate N: P Stoichiometric Homeostasis by Changing Phosphorus Contents in Their Frass
Description
Nitrogen (N) and phosphorus (P) are important limiting nutrients for plant production and consumer performance in a variety of ecosystems. As a result, the N:P stoichiometry of herbivores has received increased attention in ecology. However, the mechanisms by which herbivores maintain N:P stoichiometric homeostasis are poorly understood. Here, using a field manipulation experiment we show that the grasshopper Oedaleus asiaticus maintains strong N:P stoichiometric homeostasis regardless of whether grasshoppers were reared at low or high density. Grasshoppers maintained homeostasis by increasing P excretion when eating plants with higher P contents. However, while grasshoppers also maintained constant body N contents, we found no changes in N excretion in response to changing plant N content over the range measured. These results suggest that O. asiaticus maintains P homeostasis primarily by changing P absorption and excretion rates, but that other mechanisms may be more important for regulating N homeostasis. Our findings improve our understanding of consumer-driven P recycling and may help in understanding the factors affecting plant-herbivore interactions and ecosystem processes in grasslands.
ContributorsZhang, Zijia (Author) / Elser, James (Author) / Cease, Arianne (Author) / Zhang, Ximei (Author) / Yu, Qiang (Author) / Han, Xingguo (Author) / Zhang, Guangming (Author) / College of Liberal Arts and Sciences (Contributor) / School of Life Sciences (Contributor) / Julie Ann Wrigley Global Institute of Sustainability (Contributor) / School of Sustainability (Contributor)
Created2014-08-04
Description
A large fraction of the world grasslands and savannas are undergoing a rapid shift from herbaceous to woody-plant dominance. This land-cover change is expected to lead to a loss in livestock production (LP), but the impacts of woody-plant encroachment on this crucial ecosystem service have not been assessed. We evaluate how tree cover (TC) has affected LP at large spatial scales in rangelands of contrasting social–economic characteristics in the United States and Argentina. Our models indicate that in areas of high productivity, a 1% increase in TC results in a reduction in LP ranging from 0.6 to 1.6 reproductive cows (Rc) per km[superscript 2]. Mean LP in the United States is 27 Rc per km[superscript 2], so a 1% increase in TC results in a 2.5% decrease in mean LP. This effect is large considering that woody-plant cover has been described as increasing at 0.5% to 2% per y. On the contrary, in areas of low productivity, increased TC had a positive effect on LP. Our results also show that ecological factors account for a larger fraction of LP variability in Argentinean than in US rangelands. Differences in the relative importance of ecological versus nonecological drivers of LP in Argentina and the United States suggest that the valuation of ecosystem services between these two rangelands might be different. Current management strategies in Argentina are likely designed to maximize LP for various reasons we are unable to explore in this effort, whereas land managers in the United States may be optimizing multiple ecosystem services, including conservation or recreation, alongside LP.
ContributorsAnadon, Jose Daniel (Author) / Sala, Osvaldo (Author) / Turner II, B. L. (Author) / Bennett, Elena M. (Author) / College of Liberal Arts and Sciences (Contributor) / School of Life Sciences (Contributor) / Julie Ann Wrigley Global Institute of Sustainability (Contributor) / School of Sustainability (Contributor) / School of Geographical Sciences and Urban Planning (Contributor)
Created2014-09-02
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 purpose of this project was to discuss the physiological effects of isolation on the human body and how the body adapts. Through reviewing stories and studies of social and perceptual isolation, the adaptations of the human mind are detailed. This project explores the experiences of prisoners, sensory deprivation tanks, cave explorations, as well as studies involving monkeys and carpenter ants. The adaptations witnessed include hallucinations, increased mortality, anxiety, agitation, altered sense of time, delayed response, and lowered blood pressure. Knowing the factors surrounding the isolation experience is crucial to understand the presenting adaptation methods. These factors include duration, voluntary or involuntary participation, mental strength, and the restriction level of the isolation.
DISCLAIMER: Due to the unexpected COVID-19 pandemic, the attached podcast is a draft recording in lieu of the final recording
DISCLAIMER: Due to the unexpected COVID-19 pandemic, the attached podcast is a draft recording in lieu of the final recording
ContributorsSidhu, Nimrit (Co-author) / Deacon, Hannah (Co-author) / Hyatt, JP (Thesis director) / Kingsbury, Jeffrey (Committee member) / School of Social Work (Contributor) / College of Health Solutions (Contributor) / Arizona State University. College of Nursing & Healthcare Innovation (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
Description
I have conducted a creative that captures the power of women through an artistic perspective. The title of the creative project is “A Tribute to the Women Among us,” because this project’s purpose is to express gratitude for the women that fought for the rights I have today, and for the women I encounter in marches, continuing the fight. I have taken photographs of women and children at women's marches in the United States and in France, yielding a total of 10 photographs I will be presenting at my defense, and printing out to sell. All the profits made from the photographs will be donated to planned parenthood.
ContributorsMiss Ozuna, Alejandra Miss (Author) / Anand, Julia (Thesis director) / Mesch, Claudia (Committee member) / School of Politics and Global Studies (Contributor) / Department of Psychology (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
This research project investigated known and novel differential genetic variants and their associated molecular pathways involved in Type II diabetes mellitus for the purpose of improving diagnosis and treatment methods. The goal of this investigation was to 1) identify the genetic variants and SNPs in Type II diabetes to develop a gene regulatory pathway, and 2) utilize this pathway to determine suitable drug therapeutics for prevention and treatment. Using a Gene Set Enrichment Analysis (GSEA), a set of 1000 gene identifiers from a Mayo Clinic database was analyzed to determine the most significant genetic variants related to insulin signaling pathways involved in Type II Diabetes. The following genes were identified: NRAS, KRAS, PIK3CA, PDE3B, TSC1, AKT3, SOS1, NEU1, PRKAA2, AMPK, and ACC. In an extensive literature review and cross-analysis with Kegg and Reactome pathway databases, novel SNPs located on these gene variants were identified and used to determine suitable drug therapeutics for treatment. Overall, understanding how genetic mutations affect target gene function related to Type II Diabetes disease pathology is crucial to the development of effective diagnosis and treatment. This project provides new insight into the molecular basis of the Type II Diabetes, serving to help untangle the regulatory complexity of the disease and aid in the advancement of diagnosis and treatment. Keywords: Type II Diabetes mellitus, Gene Set Enrichment Analysis, genetic variants, KEGG Insulin Pathway, gene-regulatory pathway
ContributorsBucklin, Lindsay (Co-author) / Davis, Vanessa (Co-author) / Holechek, Susan (Thesis director) / Wang, Junwen (Committee member) / Nyarige, Verah (Committee member) / School of Human Evolution & Social Change (Contributor) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Residential Choice’s Impact on Sustainable Transportation Options: A Study in the Phoenix Metro Area
Description
This study adds to the literature about residential choice and sustainable transportation. Through the interviews and the personal stories gathered, there was diversity shown in the residential location choice process. We also noticed that “commute” means different things to different households, and that many people did not consider their commute to work to be a primary factor determining their final home location. Moreover, many people were willing to increase their commute time, or trade access to desirable amenities for a longer commute. Commuting time to work was one example of the tradeoffs that homeowners make when choosing a home, but there were also others such as architectural type and access to neighborhood amenities. Lastly, time constraints proved to be a very significant factor in the home buying process. Several of our households had such strict time constraints that limited their search to a point of excluding whole areas. Overall, our study sheds light on transportation’s role in residential choice and underscores the complexity of the location choice process.
ContributorsKats, Elyse Nicole (Author) / Salon, Deborah (Thesis director) / Kuminoff, Nicolai (Committee member) / School of Sustainability (Contributor) / School of Geographical Sciences and Urban Planning (Contributor) / School of Community Resources and Development (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
“Let Food be Thy Medicine” focuses on alternative treatment for patients suffering from obesity, diabetes mellitus type 2, hypertension, and coronary artery disease. Nutrition is an important aspect of overall health and can contribute to prevention and management of these conditions, especially when combined with medication and physical activity. Obesity is a condition that people worldwide struggle with. Adequate nutrition can play a major role in contributing to the prevention of and management of obesity not only through calorie and macronutrient intake but also by affecting hormonal and energy balances in the body. Recommended physical activity levels are included along with dietary
utritional intake recommendations on the educational pamphlet to give patients a starting guideline and better understanding how to help this condition. Type 2 diabetes, high blood pressure, and coronary artery disease are also common conditions treated by healthcare professionals. There are currently several medications on the market to help manage these conditions that range in price and have many side effects. Nutrition and exercise are two factors that can further contribute to the management of type 2 diabetes, high blood pressure, and coronary artery disease, but they can also help prevent and delay their onset. Nutrition and physical activity education along with examples of certain foods that can aid in reaching nutritional goals are outlined in the educational pamphlet to give patients a visual of what is in the academic paper.
utritional intake recommendations on the educational pamphlet to give patients a starting guideline and better understanding how to help this condition. Type 2 diabetes, high blood pressure, and coronary artery disease are also common conditions treated by healthcare professionals. There are currently several medications on the market to help manage these conditions that range in price and have many side effects. Nutrition and exercise are two factors that can further contribute to the management of type 2 diabetes, high blood pressure, and coronary artery disease, but they can also help prevent and delay their onset. Nutrition and physical activity education along with examples of certain foods that can aid in reaching nutritional goals are outlined in the educational pamphlet to give patients a visual of what is in the academic paper.
ContributorsCarson, Caitlin Colleen (Author) / Day, Kimberly (Thesis director) / Levinson, Simin (Committee member) / Arizona State University. College of Nursing & Healthcare Innovation (Contributor) / College of Health Solutions (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
This paper reviews a creative project designed to enhance the simulation experience for College of Nursing and Health Innovation nursing students at Arizona State University. Simulation allows students to practice imperative skills in a safe environment, free from the risk of injury to patients and the consequences of making these errors, in order to master skills that are essential in the clinical setting. Students are able to practice a wide range of invasive and noninvasive skills and hone in on their clinical judgement and critical thinking to make decisions that may be life threatening in a clinical situation. The group members designed written training materials and created corresponding video vignettes that would be utilized to enhance the confederate role and provide the students a deeper understanding of their simulated patient and the simulation scenario. The written training materials that were developed include confederate background information, patient and family education, and guided questions and answers for the video vignettes. The written training materials will be used to guide the students that are portraying the family member during the simulation. Trained standardized patients were hired to play the confederate role in the four video vignettes. The video vignettes portrayed interviews with a family member of the patient that delved into how they felt about their family member's hospitalization and what they hoped to learn from the nurses during their family member's hospitalization. The vignettes will be used to guide students to the needs of the patients and families in the corresponding scenarios. These vignettes will be accessible by students before the start of simulation in order to enhance understanding of the patient and ultimately, the scenario.
ContributorsBenn, Allie (Co-author) / Kiesling, Hannah (Co-author) / O'Brien, Janet (Thesis director) / Calacci, Margaret (Committee member) / Arizona State University. College of Nursing & Healthcare Innovation (Contributor) / Barrett, The Honors College (Contributor)
Created2018-12