Digital Commons Network^™

Characterization Of The Cylinderical Split Internal-Loop Photobioreactor With Scenedesmus Microalgae: Advanced Culturing, Modeling, And Hydrodynamics, Laith S. Sabri

Doctoral Dissertations

"Microalgae are fast growing photoynthetic microorganisms and it have very wide range of industrial applications such as biofuels and wastewater treatment. These cells can be grown in a wide variety of systems ranging from open culture systems (e.g., ponds) to closed culture systems of photobioreactor (e.g., airlift). The open culture systems exist in the external environment, and hence, are not intrinsically controllable. However, the microalgae production in enclosed photobioreactors faces prohibitively high production costs with special difficulty in reactor design and scale-up. The light availability and utilization efficiency in the photobioreactor in terms of design and scale-up consider as the …

Predicting Happiness - Comparison Of Supervised Machine Learning Techniques Performance On A Multiclass Classification Problem, Dorota Nieciecka

Dissertations

In the modern world, especially in contemporary economies and politics, a population's subjective well-being is a frequent subject of the public debate. As comparisons of happiness levels in different countries are published, different circumstances and their effect on the value of the subjective well-being reported by people are also analysed. However, a significant amount of the research related to subjective well-being and its determinants is still based upon survey answers and employing conventional statistical methods providing details regarding correlations and causality between different factors and subjective well-being. Application of Supervised Machine Learning techniques for prediction of subjective well-being may provide …

A Systems Approach To Research And Innovation For Food System Transformation, M. Gill, A.C.L. Den Boer, K.P. Kok, Jean Cahill, C. Callenius, P. Caron, Z. Damianova, M.A. Gurinovic, L. Lahteenmaki, T. Lang, A. Lappiere, C. Mango, J. Ryder, R. Sonnino, H. Westhoek, B.J. Regeer, J.E.W. Broerse

Research and Innovation - Other

This policy brief of the European Union (EU) Think Tank – part of the FIT4FOOD2030 Coordination and Support Action (CSA) of the FOOD 2030 initiative – is a response and contribution to growing pleas for a ‘systems approach’ to transform food systems for Food and Nutrition Security (FNS) for present and future generations. This policy brief specifically focusses on the necessity of the adoption of a systems approach to Research and Innovation (R&I) in order to foster the transformation of food systems.

Water-Energy-Food Nexus Stakeholder Information Sharing And Engagement Workshop, Rudolph A. Rosen, Bassel Daher, Rabi Mohtar

Water Resources Science and Technology Book and E-Book Publications and Reports (Archived)

On January 10, 2018, the Texas A&M University System Water-Energy-Food Initiative held the Water-Energy-Food Nexus Stakeholder Information Sharing and Engagement Workshop on the campus of Texas A&M University-San Antonio. The workshop involved over 70 stakeholders drawn from the water, energy, and food sectors in San Antonio and surrounding region. Stakeholders attending the workshop heard presentations on the status of San Antonio Case Study pilot projects and other WEF nexus work. Facilitated small-group sessions were held at the workshop to obtain stakeholder input on research questions to be asked, and on limitations and opportunities for stakeholder engagement on WEF nexus-related work …

A Multi-Criteria And Dynamic Sustainability Assessment Of Crop Rotation Alternatives, Saturnina Fabian Nisperos

Computational Modeling & Simulation Engineering Theses & Dissertations

With the food security challenge faced by nations globally, agriculture sustainability has been a significant consideration for concerned agencies. Sustainability assessments are significant tools in providing support to stakeholders in their crop production planning. Agricultural sustainability assessment, however, is complex and it involves numerous criteria that can be conflicting. Limitations on crop rotation sustainability assessment methods include: non-dynamic assessment; lack of regard to cover crops and to the individual crop production preferences of farmers; and focused only on single-year and single-crop rotation. We sought to address these limitations by developing a multi-criteria and dynamic sustainability assessment model that considers the …

Temporal Trends In Human Vulnerability To Excessive Heat, Scott C. Sheridan, Michael J. Allen

Political Science & Geography Faculty Publications

Over recent decades, studies have examined various morbidity and mortality outcomes associated with heat exposure. This review explores the collective knowledge of the temporal trends of heat on human health, with regard to the hypothesis that humans are less vulnerable to heat events presently than in the past. Using Web of Science and Scopus, the authors identified all peer-reviewed articles that contained keywords on human impact (e.g. mortality, morbidity) and meteorological component (e.g. heat, heatwave). After sorting, a total of 71 articles, both case studies and epidemiological studies, contained explicit assessments of temporal trends in human vulnerability, and thus were …

Netnographic Slog: Creative Elicitation Strategies To Encourage Participation In An Online Community Of Practice For Early Education And Care, Ruth Wallace

Research outputs 2014 to 2021

Active, participatory netnography, in contrast to passive netnography, is essential if researchers are to gain rich rewards from the rigorous collection of qualitative data. However, researchers should be aware of the ‘netnographic slog’; “the blood, sweat and tears” associated with eliciting quality data and encouraging active participation in online communities.

This article examines the – Supporting Nutrition for Australian Childcare (SNAC) – online community of practice, established to support healthy eating practices in early childhood education and care settings. To ensure research rigour, Kozinets’ netnographic steps were employed. Garnering member participation in this online community was a slog; most community …

Habitat Characteristics Provide Insights Of Carbon Storage In Seagrass Meadows, Inés Mazarrasa, Jimena Samper-Villarreal, Oscar Serrano, Paul S. Lavery, Catherine E. Lovelock, Núrià N. Marbà, Carlos M. Duarte, Jorge A. Cortés

Research outputs 2014 to 2021

Seagrass meadows provide multiple ecosystem services, yet they are among the most threatened ecosystems on earth. Because of their role as carbon sinks, protection and restoration of seagrass meadows contribute to climate change mitigation. Blue Carbon strategies aim to enhance CO2 sequestration and avoid greenhouse gasses emissions through the management of coastal vegetated ecosystems, including seagrass meadows. The implementation of Blue Carbon strategies requires a good understanding of the habitat characteristics that influence Corg sequestration. Here, we review the existing knowledge on Blue Carbon research in seagrass meadows to identify the key habitat characteristics that influence Corg sequestration in seagrass …

Wintering American Black Duck Ecology Of Central Appalachia, Sara E. Yannuzzi

Graduate Theses, Dissertations, and Problem Reports (ETD)

The American black duck (Anas rubripes) is a species of dabbling duck found only in the northeastern part of North America, and widely hunted until its decline. Since the 1950s, the total population has decreased by 53%. Habitat degradation and decline of wintering and breeding wetlands, historic overharvest, and interactions with the mallard (A. platyrhynchos) are attributed as some of the main causes of the black duck population’s decrease. Many policies and taxa- and habitat-specific joint ventures have since been created to aid in studying and improving North American wetlands and black duck populations throughout both their breeding and wintering …

Public Elementary School Teachers' Experiences With Implementing Outdoor Classrooms, Lori Schultz Goff

Walden Dissertations and Doctoral Studies

Children experience limited time outdoors and have few opportunities for outdoor learning in schools, putting them at risk for being unprepared to engage in solving environmental and societal problems. Researchers have examined outdoor learning at the preschool and high school levels; elementary school experiences have been explored less frequently. Guided by a conceptual framework informed by social emotional learning (SEL), ecological literacy, and teacher self-efficacy, this study investigated public school elementary teachers' experiences with outdoor classrooms including barriers and supports to creating and using outdoor classrooms. A qualitative design using in-depth interviews with interpretive phenomenological analysis techniques was conducted with …

Success Factors Of Entrepreneurship In Emerging Rural Economies, Sultan Tahir Mehmood

Walden Dissertations and Doctoral Studies

One factor of the leadership stratagem is to account for the core values, operations, and growth of the organization. The purpose of this case study was to ascertain the financial strategies small business leaders incorporate to help ensure growth of small businesses. The conceptual framework of Schumpeter's innovation and entrepreneurship theory and the Grameen model were included to drive the scope and analysis of this study. A purposive sample of 8 leaders from successful small businesses in Islamabad contributed to a focus group session; 4 out of these participants originated from the finance and management department and 4 represented sales …

Socioeconomic Characteristics Of Farmers And Agrochemical Use In Grenada, Lindonne Marcia Glasgow

Walden Dissertations and Doctoral Studies

The World Health Organization classified carbaryl, glyphosate, and paraquat as hazardous to human health. In the Agriculture Health Study in the United States, health problems were associated with the use of these 3 agrochemicals 12 or more times per year. These 3 agrochemicals were commonly used in Grenada. The purpose of this quantitative cross-sectional study was to investigate the relationship between the social and economic characteristics of the farmers who participated in the 2012 agriculture survey and the use of agrochemicals at frequencies that could pose health risks. Five constructs of the social cognitive theory were used as the premise …

Relationship Between Exposure To Phthalate And Obesity In The United States, Gladys Chidiebere Ezem

Walden Dissertations and Doctoral Studies

Obesity is a public health problem. The global obesity problem has been attributed to unhealthy diet, inactivity, and hereditary factors. However, phthalates may also contribute to the obesity epidemic. The purpose of this cross-sectional study was to examine whether there was a relationship between exposure to phthalates and obesity among adults 18 years and older in the United States. The theoretical framework was based on the socioecological model. The quantitative, cross-sectional design, and data analysis were based on the National Health and Nutrition Examination Survey, 2011-2012 database. Descriptive statistics and multiple regression analysis were used to analyze the association between …

Patient Satisfaction Management In Office Visits And Telehealth In Health Care Technology, Todd Price

Walden Dissertations and Doctoral Studies

Telehealth and remote medical treatments have begun to be more commonly used in healthcare systems. Researchers have theorized that providers' abilities to treat patients are not directly tied to the proximity of the patient to the doctor, but by the identification and treatment of the patient's symptoms. Although the treatment and cure rates are being established within individual health systems and professional medical associations, empirical research is lacking regarding patient satisfaction with this remote treatment situation. The purpose of this quantitative study was to address this gap by examining satisfaction ratings of patients between virtual provider visits and face-to-face provider …

Relationships Among Vitamin D Deficiency, Metabolic Syndrome, Smoking Behavior, And Physical Activity, Ethan Pham

Walden Dissertations and Doctoral Studies

Aging increases the risk of both vitamin D deficiency and metabolic syndrome. Vitamin D deficiency and metabolic syndrome may be related, although there are mixed findings. Furthermore, literature suggests other factors such as physical fitness activity and smoking behavior are associated with Vitamin D deficiency and the development of metabolic syndrome. A number of studies have documented associations between Vitamin D levels and physical fitness activities, while other studies found correlations between Vitamin D levels, metabolic syndrome, and smoking behavior. However, no previous study has examined the links between physical fitness activity, smoking behavior, Vitamin D levels, and the risks …

Megaloads And Mobilization: The Rural People Of Idaho Stand Against Big Oil, Corrie Grosse

Environmental Studies Faculty Publications

From 2011 to 2014 fossil fuel corporations trucked tar sands processing machinery along rural Idaho highways. The machinery was bound for the world's largest deposits of tar or oil sands, a heavy crude oil substance called bitumen, located in the western Canadian province of Alberta. These loads of machinery, what became known as megaloads, encountered much resistance. Throughout Idaho and the surrounding region, a network organized opposition. Neighbors, grassroots organizations, nonprofits, and the Nez Perce and other tribes all collaborated. They held information sessions, protested, waged legal battles, monitored the loads, and blockaded highways. What oil companies hoped would be …

Exploring Technological Strategies For Valorization Of Solid Sisal Waste: A Research Review, Amelia Kivaisi, Anthony Mshandete

Tanzania Journal of Science

The sisal industry in Tanzania generates large amounts of waste which is an un-tapped bioresource. Research was undertaken to establish appropriate technologies  for its valorisation to mushrooms, biogas and biogas manure (BGM).Physical and biological pre-treatments achieved methane yield increments of 23-30% whereas co-digestion with fish waste achieved methane yield increments of 59-94%. Sisal fibre waste was demonstrated to be a novel biofilm-carrier for treating sisal pulp leachate. With a loading rate of 9.0 kgVS/m3/day, the packed-bed bioreactor was operated without process stress. Sisal decortication waste (SLDW) and sisal boles (SBW) were found to be suitable for oyster mushroom cultivation. With …

The Chemistry And Biology Of Iron-Scavenging Natural Products From Pathogenic Acinetobacter Baumannii, Justin Shapiro

Arts & Sciences Graduate Student Theses and Dissertations

Multidrug resistant (MDR) Gram-negative bacteria represent a global health crisis. Traditional antibiotics create selective pressure and breed resistance, making our current drugs less and less effective. Targeting of bacterial virulence factors has gained interest as an alternative strategy to potentially circumvent this problem. Virulent Acinetobacter baumannii synthesize and secrete pre-acinetobactin, a small molecule metal chelator that scavenges life-sustaining iron and is critical for establishing infection. The work described herein sheds light on the unusual properties of a non-enzymatic isomerization from pre-acinetobactin to acinetobactin and proposes a siderophore-swapping mechanism by which A. baumannii expands its pH window for virulence. Knowledge from …

Seasonal Resource Selection And Habitat Treatment Use By A Fringe Population Of Greater Sage-Grouse, Rhett Boswell

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Movement and habitat selection by Greater Sage-grouse (Centrocercus uropasianus) is of great interest to wildlife managers tasked with applying conservation measures for this iconic western species. Current technology has created small and lightweight GPS (Global Positioning Systems) transmitters that can be attached to sage-grouse. Using GIS software and statistical programs such as Program R, land managers can analyze GPS location data to assess how sage-grouse are geospatially interacting with their habitats. Within the Panguitch Sage-Grouse Management Area (SGMA) thousands of acres of land have been restored or manipulated to enhance sage-grouse habitat; this usually involves removal of pinyon pine …

Synthesis And Characterization Of Thermoresponsive Hydrogels Based On N-Isopropylacrylamide Crosslinked With 4,4′-Dihydroxybiphenyl Diacrylate, Shuo Tang, Martha Floy, Rohit Bhandari, Manjula Sunkara, Andrew J. Morris, Thomas D. Dziubla, J. Zach Hilt

Chemical and Materials Engineering Faculty Publications

A novel crosslinker [4,4′-dihydroxybiphenyl diacrylate (44BDA)] was developed, and a series of temperature-responsive hydrogels were synthesized through free radical polymerization of N-isopropylacrylamide (NIPAAm) with 44BDA. The temperature-responsive behavior of the resulting gels was characterized by swelling studies, and the lower critical solution temperature (LCST) of the hydrogels was characterized through differential scanning calorimetry. Increased content of 44BDA led to a decreased swelling ratio and shifted the LCST to lower temperatures. These novel hydrogels also displayed resiliency through multiple swelling–deswelling cycles, and their temperature responsiveness was reversible. The successful synthesis of NIPAAm-based hydrogels crosslinked with 44BDA has led to a …

Pros And Cons Of Marine Zoological Parks According To Marine Conservationists, Kayla L. Patama

HCNSO Student Capstones

Throughout history zoos and aquariums have satisfied a number of different, albeit to some, conflicting roles (Ballantyne, Packer, Hughes, & Dierking, 2007). In recent years, zoos and aquariums have shifted their focus on taking a proactive role in wildlife conservation and promoting conservation learning among their visitors. The present capstone addresses the justifications that marine conservationists see in marine zoological parks and how they believe parks can become more relevant and valuable in the future. A 65 question survey (Appendix I) was distributed to marine science professionals online through personal contact between June and September 2017 questioning participant’s personal opinions …

The Value Of Native Plants And Local Production In An Era Of Global Agriculture, Oren Shelef, Peter J. Weisberg, Frederick D. Provenza

Wildland Resources Faculty Publications

For addressing potential food shortages, a fundamental tradeoff exists between investing more resources to increasing productivity of existing crops, as opposed to increasing crop diversity by incorporating more species. We explore ways to use local plants as food resources and the potential to promote food diversity and agricultural resilience. We discuss how use of local plants and the practice of local agriculture can contribute to ongoing adaptability in times of global change. Most food crops are now produced, transported, and consumed long distances from their homelands of origin. At the same time, research and practices are directed primarily at improving …

Short-Term Toxicity Of 1-Methylnaphthalene To Americamysis Bahia And 5 Deep-Sea Crustaceans, Anthony H. Knap, Nicholas R. Turner, Gopal Bera, Dorothy-Ellen A. Renegar, Tamara Frank, Jose Sericano, Bernhard Riegl

Marine & Environmental Sciences Faculty Articles

There are few studies that have evaluated hydrocarbon toxicity to vertically migrating deep-sea micronekton. Crustaceans were collected alive using a 9-m² Tucker trawl with a thermally insulated cod end and returned to the laboratory in 10 °C seawater. Toxicity of the polycyclic aromatic hydrocarbon 1-methylnaphthalene to Americamysis bahia, Janicella spinacauda, Systellaspis debilis, Sergestes sp., Sergia sp., and a euphausiid species was assessed in a constant exposure toxicity test utilizing a novel passive dosing toxicity testing protocol. The endpoint of the median lethal concentration tests was mortality, and the results revealed high sensitivity of the deep-sea micronekton …

The Monadnock Volume 59, December 2017, Clark University Geographical Society

The Monadnock (Clark Geographical Society)

Volume 59 of The Monadnock. The Monadnock was the alumni magazine of the Clark University Geographical Society (1927-1985) (2014-present).

Effects Of Ocean Warming And Acidification On Fertilization Success And Early Larval Development In The Green Sea Urchin, Lytechinus Variegatus, Brittney L. Lenz

HCNSO Student Theses and Dissertations

Climate change is predicted to affect the larval stages of many marine organisms. Ocean warming can reduce larval survival and hasten larval development, whereas ocean acidification can delay larval development. Ocean acidification is especially concerning for marine organisms that develop and grow calcified shells or skeletons in an environment undersaturated with calcium carbonate minerals. This study assessed the effects of ocean warming and acidification on the fertilization and larval development of the green sea urchin, Lytechinus variegatus, a tropical species common in Florida and the Caribbean. After spawning, gametes were fertilized and embryos/larvae were reared at: 1) 28°C and …

Openebgm: An R Implementation Of The Gamma-Poisson Shrinker Data Mining Model, Travis Canida, John Ihrie

The R Journal

We introduce the R package openEBGM, an implementation of the Gamma-Poisson Shrinker (GPS) model for identifying unexpected counts in large contingency tables using an empirical Bayes approach. The Empirical Bayes Geometric Mean (EBGM) and quantile scores are obtained from the GPS model estimates. openEBGM provides for the evaluation of counts using a number of different methods, including the model-based disproportionality scores, the relative reporting ratio (RR), and the proportional reporting ratio (PRR). Data squashing for computational efficiency and stratification for confounding variable adjustment are included. Application to adverse event detection is discussed.

Furniture For Quantitative Scientists, Tyson S. Barrett, Emily Brignone

The R Journal

A basic understanding of the distributions of study variables and the relationships among them is essential to inform statistical modeling. This understanding is achieved through the computation of summary statistics and exploratory data analysis. Unfortunately, this step tends to be under-emphasized in the research process, in part because of the often tedious nature of thorough exploratory data analysis. The table1() function in the furniture package streamlines much of the exploratory data analysis process, making the computation and communication of summary statistics simple and beautiful while offering significant time-savings to the researcher

Strengths And Limitations Of Nitrogen Rate Recommendations For Corn And Opportunities For Improvement, Thomas F. Morris, T. Scott Murrell, Douglas B. Beegle, James J. Camberato, Richard B. Ferguson, John H. Grove, Quirine Ketterings, Peter M. Kyveryga, Carrie A.M. Laboski, Joshua M. Mcgrath, John J. Meisinger, Jeff Melkonian, Bianca N. Moebius-Clune, Emerson D. Nafziger, Deanna Osmond, John E. Sawyer, Peter C. Scharf, Walter Smith, John T. Spargo, Harold M. Van Es, Haishun Yang

Plant and Soil Sciences Faculty Publications

Nitrogen fi xation by the Haber–Bosch process has more than doubled the amount of fi xed N on Earth, significantly influencing the global N cycle. Much of this fi xed N is made into N fertilizer that is used to produce nearly half of the world’s food. Too much of the N fertilizer pollutes air and water when it is lost from agroecosystems through volatilization, denitrification, leaching, and runoff. Most of the N fertilizer used in the United States is applied to corn (Zea mays L.), and the profitability and environmental footprint of corn production is directly tied to N …

Making Models With Bayes, Pilar Olid

Electronic Theses, Projects, and Dissertations

Bayesian statistics is an important approach to modern statistical analyses. It allows us to use our prior knowledge of the unknown parameters to construct a model for our data set. The foundation of Bayesian analysis is Bayes' Rule, which in its proportional form indicates that the posterior is proportional to the prior times the likelihood. We will demonstrate how we can apply Bayesian statistical techniques to fit a linear regression model and a hierarchical linear regression model to a data set. We will show how to apply different distributions to Bayesian analyses and how the use of a prior affects …

Upland Cotton (Gossypium Hirsitum) Root Responses To Reniform Nematode (Rotylenchulus Reniformis) Infection, Wei Li

All Dissertations

Reniform nematode (Rotylenchulus reniformis) is a semi-endoparasitic nematode that causes yield losses in numerous crops, including upland cotton (Gossypium hirsutum). Resistant cotton varieties are urgently needed, but the molecular basis of nematode-host plant interactions is poorly understood. To document plant responses to reniform nematode infection in upland cotton roots, we set up a split-root growth system to collect tissues from infected and uninfected portions of the same root system. A 12-day time course of histology and gene expression of infected roots were generated in Chapter 1. Results suggest reniform nematode infection induced protein synthesis and transport, …