Digital Commons Network^™

Viral Chemotaxis Of Paramecium Bursaria Altered By Algal Endosymbionts, Huy V.N. Ho, David Dunigan, Miranda E. Salsbery, Irina Agarkova, Zeina Al-Ameeli, James L. Van Etten, John Delong

School of Biological Sciences: Faculty Publications

Chemotaxis is widespread across many taxa and often aids resource acquisition or predator avoidance. Species interactions can modify the degree of movement facilitated by chemotaxis. In this study, we investigated the influence of symbionts on Paramecium bursaria’s chemotactic behavior toward chloroviruses. To achieve this, we performed choice experiments using chlorovirus and control candidate attractors (virus stabilization buffer and pond water). We quantified the movement of Paramecia grown with or without algal and viral symbionts toward each attractor. All Paramecia showed some chemotaxis toward viruses, but cells without algae and viruses showed the most movement toward viruses. Thus, the endosymbiotic …

Metamorphosis Imposes Variable Constraints On Genome Expansion Through Effects On Development, R. Lockridge Mueller, Clayton E. Cressler, R. S. Schwartz, R. A. Chong, M. A. Butler

School of Biological Sciences: Faculty Publications

Genome size varies ∼100,000-fold across eukaryotes and has long been hypothesized to be influenced by meta- morphosis in animals. Transposable element accumulation has been identified as a major driver of increase, but the nature of constraints limiting the size of genomes has remained unclear, even as traits such as cell size and rate of development co-vary strongly with genome size. Salamanders, which possess diverse metamorphic and non-metamorphic life histories, join the lung- fish in having the largest vertebrate genomes—3 to 40 times that of humans—as well as the largest range of variation in genome size. We tested 13 biologically-inspired hypotheses …

To What Extent Do Physiological Tolerances Determine Elevational Range Limits Of Mammals?, Jay F. Storz, Graham R. Scott

School of Biological Sciences: Faculty Publications

A key question in biology concerns the extent to which distributional range limits of species are determined by intrinsic limits of physiological tolerance. Here, we use common-garden data for wild rodents to assess whether species with higher elevational range limits typically have higher thermogenic capacities in comparison to closely related lowland species. Among South American leaf-eared mice (genus Phyllotis), mean thermogenic performance is higher in species with higher elevational range limits, but there is little among-species variation in the magnitude of plasticity in this trait. In the North American rodent genus Peromyscus, highland deermice (Peromyscus maniculatus) …

Stochasticity Directs Adaptive Evolution Toward Nonequilibrium Evolutionary Attractors, John Delong, Clayton E. Cressler

School of Biological Sciences: Faculty Publications

Stochastic processes such as genetic drift may hinder adaptation, but the effect of such stochasticity on evolution via its effect on ecological dynamics is poorly understood. Here we evaluate patterns of adaptation in a population subject to variation in demographic stochasticity. We show that stochasticity can alter population dynamics and lead to evolutionary outcomes that are not predicted by classic eco-evolutionary modeling approaches. We also show, however, that these outcomes are governed by nonequilibrium evolutionary attractors— these are maxima in lifetime reproductive success when stochasticity keeps the ecological system away from the deterministic equilibrium. These NEEAs alter the path of …

The Consumption Of Viruses Returns Energy To Food Chains, John Delong, James L. Van Etten, Zeina Al-Ameeli, Irina Agarkova, David Dunigan

School of Biological Sciences: Faculty Publications

Viruses impact host cells and have indirect effects on ecosystem processes. Plankton such as ciliates can reduce the abundance of virions in water, but whether virus consumption translates into demographic consequences for the grazers is unknown. Here, we show that small protists not only can consume viruses they also can grow and divide given only viruses to eat. Moreover, the ciliate Halteria sp. foraging on chloroviruses displays dynamics and interaction parameters that are similar to other microbial trophic interactions. These results suggest that the effect of viruses on ecosystems extends beyond (and in contrast to) the viral shunt by redirecting …

Intraguild Predation Is Increased In Areas Of Low Prey Diversity In A Generalist Predator Community, Stella F Uiterwaal, Amber Squires, Bennett Grappone, Brian Dillard, Ariadne Castaneda, Sora L. Kim, John Delong

School of Biological Sciences: Faculty Publications

1. Niche differentiation and intraguild predation (IGP) can allow ecologically similar species to coexist, although it is unclear which coexistence mechanism predominates in consumer communities. Until now, a limited ability to quantify diets from metabarcoding data has precluded the use of sequencing data to determine the relative importance of these mechanisms.

2. Here, we pair a recent metabarcoding quantification approach with stable isotope analysis to examine diet composition in a wolf spider community.

3. We compare the prevalence of resource partitioning and IGP in these spiders and test whether factors that influence foraging performance, including individual identity, morphology, prey community …

Pathways Of Density Dependence And Natural Selection In Modern Humans, John Delong

School of Biological Sciences: Faculty Publications

Living things depend on a flow of energy and materials to grow, reproduce, and maintain their bodies. Populations are aggregations of individuals, so they too depend on resources. Humans use many fuels derived from the Earth’s photosynthetic energy, which in turn support a population that often occurs at unusually high densities for a mammal. Like most populations, growing human populations may experience negative feedbacks from population size unless the socio-economic system in which the population lives grows fast enough to maintain resource flows to individuals and to limit the downsides of high density. I map out a simple view of …

Functionally Redundant Multimodal Predator Cues Elicit Changes In Prey Foraging Behavior, Fiona G. Shogren, Eileen Hebets, John Delong

School of Biological Sciences: Faculty Publications

Many prey species can assess the risk of predation from information acquired through different sensory systems. For many animals, this information is detected with sensory organs specialized for visual (sight) or chemical (smell or taste) stimuli. It is unclear; however, whether information acquired through multiple sensory systems is functionally redundant or interchangeable, especially if the message is the same. Here, we assess prey response to unimodal visual and chemical cues as well as multimodal (visual + chemical) cues. We specifically test if a foraging individual shows a stronger behavioral response to risk when they can perceive that risk through multimodal …

Gene Regulatory Changes Underlie Developmental Plasticity In Respiration And Aerobic Performance In Highland Deer Mice, Rena M. Schweizer, Catherine M. Ivy, Chandrasekhar Natarajan, Graham R. Scott, Jay F. Storz, Zachary A. Cheviron

School of Biological Sciences: Faculty Publications

Phenotypic plasticity can play an important role in the ability of animals to tolerate environmental stress, but the nature and magnitude of plastic responses are often specific to the developmental timing of exposure. Here, we examine changes in gene expression in the diaphragm of highland deer mice (Peromyscus maniculatus) in response to hypoxia exposure at different stages of development. In highland deer mice, developmental plasticity in diaphragm function may mediate changes in several respiratory traits that influence aerobic metabolism and performance under hypoxia. We generated RNAseq data from diaphragm tissue of adult deer mice exposed to (1) life-long …

Higher Concentrations Of Microplastics In Runoff From Biosolid-Amended Croplands Than Manure-Amended Croplands, Nasrin Naderi Beni, Shahab Karimifard, John Gilley, Tiffany Messer, Amy Schmidt, Shannon L. Bartelt-Hunt

Department of Civil and Environmental Engineering: Faculty Publications

Land-applied municipal biosolids, produced from municipal wastewater treatment sludge, contributes to microplastics contamination in agroecosystems. The impacts of biosolids on microplastic concentrations in agricultural soil have been previously investigated, however, the potential for microplastics transport from biosolid-amended croplands has not been previously quantified. In this study, manure and biosolids were applied to field plots, runoff was collected following natural precipitation events and the potential of bacterial biofilm to grow on different microplastic morphologies was investigated. Higher concentrations of microplastics were detected in runoff from plots with land-applied biosolid in comparison with manure-amended and control plots. Fibers and fragments were the …

Histidine Enhances The Anticancer Effect Of Gemcitabine Against Pancreatic Cancer Via Disruption Of Amino Acid Homeostasis And Oxidant—Antioxidant Balance, Narendra Kumar, Satyanarayana Rachagani, Gopalakrishnan Natarajan, Alexandra Crook, Thiyagarajan Gopal, Vinothkumar Rajamanickam, Jyoti B. Kaushal, Sirpu N. Nagabhishek, Robert Powers, Surinder K. Batra, Viswanathan Saraswathi

Robert Powers Publications

Simple Summary: Amino acid metabolism is aberrantly altered in pancreatic cancer (PC). Evidence suggests that circulating histidine (His) levels are low in PC. However, the role of His in modulating the progression of PC remains unknown. We determined the role of His in altering the therapeutic effectiveness of gemcitabine (Gem) against PC. We provide evidence that the expression of histidine ammonia lyase (HAL), an enzyme involved in His catabolism, is greatly increased in mouse and human pancreatic tumors. We show that combining His with Gem led to enhanced cytotoxic effects against aggressive PC cell lines. Our metabolomics analysis revealed that …

Germination And Simulated Gastrointestinal Digestion Of Chickpea (Cicer Arietinum L.) In Exhibiting In Vitro Antioxidant Activity In Gastrointestinal Epithelial Cells, Ashley Newton, Kaustav Majumder

Department of Food Science and Technology: Faculty Publications

Plant-based proteins, in particular pulse proteins, have grown in popularity worldwide. Germination, or sprouting, is an effective method to release peptides and other dietary compounds. However, the combination of germination and gastrointestinal digestion in enhancing the release of dietary compounds with potential health-beneficial biological activity has yet to be entirely elucidated. The present study illustrates the impact of germination and gastrointestinal digestion on the release of dietary compounds with antioxidant activity from chickpeas (Cicer arietinum L.). Germination up to 3 days (D0 to D3) increased the peptide content by denaturing chickpea storage proteins and increased the degree of hydrolysis …

Peanut Allergen Ara H 6 Is Detectable In Blood Transfusion Products, Fleur A. C. Jansen, Klaske Van Norren, Joseph L. Baumert, Annegeet Van Den Bos, Joannes F. M. Jacobs, Stef J. Koppelman

Department of Food Science and Technology: Faculty Publications

Peanut allergen Ara h 6 is known to maintain IgE‐binding capacity upon exposure to digestive enzymes1 and its presence in circulation after consumption of peanut has been demonstrated.2,3 Therefore, it has been speculated that food‐derived allergens could be transferred via blood transfusion products, causing an allergic reaction in food-allergic recipients.4,5 However, in published case reports, presence of food allergen in donated material could not be confirmed due to lack of remaining transfusion material and/or lack of sensitive analytical methods. Using a newly developed sensitive immune‐assay for detecting Ara h 6 in human serum, we now report to what extent consumed …

Urban Screens As A Tool For Placemaking, Mona Helmy

Architectural Engineering

Urban screens, as part of the lightscape of places, can play a fundamental role in placemaking. They have the flexibility to be positioned in various locations in spaces with various sizes, shapes, moods, and effects for functional or aesthetical reasons. They can be temporary or permanent, active, or interactive instruments for creating a dynamic, stimulating, and unique public realm atmosphere that engages people and encourages social interaction. This research aims to create a theoretical framework for urban screen typologies as tools for placemaking. It investigates, explores, analyzes, and discusses different approaches where urban screens are used as a main tool …

Vida Láctea, Rodrigo De La Torre Femenía

Grado en Diseño de Interiores

No abstract provided.

Training Strategies To Improve Salesperson Confidence And Production, William B. Bronson

Walden Dissertations and Doctoral Studies

Many sales leaders need strategies to improve the productivity and confidence of their sales personnel. Ineffective sales training programs cost organizations billions of dollars in annual revenue and profits. Grounded in adaptive leadership theory, the purpose of this qualitative mini-ethnographic multiple-case study was to explore successful strategies used by sales leaders that combine and balance virtual and online resources with traditional face-to-face training methods to increase the productivity and confidence of sales personnel. Data were collected by interviewing eight salespeople and two sales managers spanning two Texas insurance companies and reviewing company documents. Data were analyzed using Yin’s five-step process …

Succession Planning Strategies For Nonprofit Organizations, Chandler Campbell

Walden Dissertations and Doctoral Studies

Nonprofit organizations are cornerstones in the community that contribute to improving environments, communities, persons, and life overall. However, some nonprofit organization senior leaders lack the succession planning strategies, resources, and funding to continue serving as positive social change agents in the community. Grounded in the general systems theory, the purpose of this qualitative single case study was to explore business strategies nonprofit leaders use for succession planning. The participants included three senior leaders in a nonprofit located in the northeastern region of the United States who have indirectly or directly implemented succession planning strategies. Data were collected through semistructured interviews, …

College Students’ Psychosocial Functioning 2 To 5 Years After Death Of A Parent, Carla C. Elbel

Walden Dissertations and Doctoral Studies

The purpose of this study is to examine the relationship regarding a loss of parent during adolescence with psychosocial development into early college years (18 through 22 years of age) as measured by the Modified Erikson Psychosocial Stage Inventory (MEPSI). A sample of 15 young college students, ages 18 to 22, completed the MEPSI and a second sample of young college students 18 to 22, who lost a parent, completed the MEPSI. No significant difference was found in the variance of the means; therefore, the null hypothesis was retained. A small sample t test analysis was used to compare the …

Experiences Of Women Faculty Using Meditative Practices Through Workplace Health Promotion In Ontario, Kelly Lynn Henley

Walden Dissertations and Doctoral Studies

Workplace stress is pervasive and changes to the postsecondary teaching and learning environment have contributed to stress among women faculty and adversely impacted their personal well-being. The purpose of this qualitative study was to understand how the constructs in the health belief model (HBM) play a role in the use of worksite wellness initiatives to manage stress and promote wellness among women postsecondary faculty in Ontario. The research questions were designed based on the HBM to examine the participants’ perceptions of severity and susceptibility to workplace stress, perceived benefits and barriers to participation, motivation to participate, and self-efficacy. Women faculty …

Beliefs Of Higher Education Online Faculty Regarding The Integration Of Multimedia, Kimberly Diane Hoyt

Walden Dissertations and Doctoral Studies

Integration of multimedia resources in higher education curricula continues to be a concern for today’s teachers, especially in identifying effective, efficient, and engaging resources that provide individualized instruction and meet a variety of learning needs. However, there was a gap in the literature regarding teachers' beliefs about multimedia integration within the context of adult learning in online higher education. The purpose of this basic qualitative study was to explore the benefits and challenges higher education online teachers experienced when integrating multimedia resources into their courses. The research question explored the beliefs of higher education online instructors about their experiences when …

Attachment Bond Experiences Among Adults Using Service Dogs To Mitigate Psychiatric Disabilities, Marcia Lynn Jackson

Walden Dissertations and Doctoral Studies

AbstractMental illness has a negative influence on U.S. society, affecting more than 21% of adults. Worldwide, approximately 264 million people are impacted by psychiatric conditions. Despite the prevalence of psychological disorders, treatment resources are lacking. As such, the addition of adjunctive therapeutic interventions could benefit society. Researchers have demonstrated that the bond formed between humans and animals offers a vital healing tool. However, there was limited information on the use of service dogs in the psychiatric population. This qualitative interpretative phenomenological analysis explored how adults with psychiatric diagnoses describe attachment to service dogs used to mitigate the symptoms of their …

Upper Elementary School Teachers’ Perceptions Of Using Audiobooks For Reluctant Readers, Richard Michael Joseph

Walden Dissertations and Doctoral Studies

The problem that prompted this study was that educators’ perceptions were unknown regarding the use of audiobooks in classroom settings to help reluctant readers develop independent reading habits at a suburban elementary school in Southeast Michigan. This lack of awareness represents a gap in practice that reflects a potential need for increased understanding about how the use of audiobooks in classroom settings may help reluctant readers develop independent reading habits. The purpose of this basic qualitative project study was to examine third through fifth grade educators’ perceptions on the use of audiobooks in classroom settings to help reluctant readers develop …

Cross-Sectional Collaboration In Florida's Emergency Management System, Christopher Stephen Kirkland

Walden Dissertations and Doctoral Studies

Florida faces a unique set of emergency management hazards prompted by the state’s geography, high volume of tourism, and position as a hub of international trade. The state has developed a highly adaptive emergency management system to deliver humanitarian assistance to Floridians affected by natural and other disasters. Despite the importance of collaboration in delivering humanitarian goods and services to Floridians in times of crisis, little is known as to how collaboration occurs, what impediments exist, and how organizations adapt to the dynamics of natural and other disasters. In this qualitative case study, the integrative framework for collaborative governance was …

Relationships Between Stress, Family Support, And Resources Among Custodial Grandparents In Appalachia, Yvonne Sherii Lee

Walden Dissertations and Doctoral Studies

The Appalachian region has experienced a substantial increase in the number of grandparent-headed households providing care to grandchildren. Custodial parenting is not a typical responsibility for many grandparents and can be challenging. The specific problem addressed in this research study was the high level of stress experienced by many custodial grandparents. The theoretical foundation of the current study was based on Selye’s stress theory, which was introduced in 1936 and examined biological stress that he referred to as “the syndrome of being sick.” The purpose of this quantitative, nonexperimental, and correlational study was to examine the predictive relationship that custodial …

English Language Arts Teachers’ Motivations And Experiences Related To Incorporating Digital Texts In Grades 6-12, Leah M. Marsh

Walden Dissertations and Doctoral Studies

Selecting text mediums that best support their curriculum needs is a critical task for English Language Arts (ELA) teachers, who also need to choose materials aligned with state standards and district requirements. Because 21st-century learning standards require students to have more technology skills, teachers are increasingly offering digital texts in classrooms. The problem under investigation in this study was the gap in understanding of the curricular choices U.S. teachers make when incorporating digital texts in ELA classrooms for Grades 6-12 to increase literacy. The purpose of this qualitative study was to examine ELA teachers’ motivation and experiences related to the …

A Quantitative Comparison Of Mass Shooting Offenders Who Preemptively Used Social Media, Heidi Mathis

Walden Dissertations and Doctoral Studies

The purpose of this quantitative study was to compare the characteristics of offenders who posted on social media for attention versus those who posted on social media for fame using discriminant factorial analysis (DFA). To date, there has been very little research done on social media usage with regards to mass shootings. The wealth of the research close to the study at hand has to do with not naming the offender and the media contingency effect. The current research helped close some of that gap. Researching social media usage and mass shootings showed how the variables: location, rejection, mental health …

Nurses' Lived Experiences Caring For Covid-19 Patients In The United States, Cynthia Rose Rodriguez

Walden Dissertations and Doctoral Studies

The COVID-19 pandemic has affected healthcare services and delivery and may leave unprecedented effects on nurses’ physical and mental health. Research is sparse on the pandemic’s effects on nurses, but studies have identified the stressful factors that may contribute to nurses’ health and well-being. The purpose of this qualitative interpretive phenomenological study was to understand the lived experiences of nurses caring for COVID-19 patients in the United States and discover how their experiences impact them on a personal and professional level. Hans Selye’s general adaptation theory served as the theoretical basis for this study with Edmund Husserl’s life worldview used …

Early Childhood Teachers’ Perspectives On Their Responses To Children’S Challenging Behaviors, Dr. Sharon Denise Scallion

Walden Dissertations and Doctoral Studies

AbstractThe problem that was the focus of this study was the high rate of suspensions and expulsions of preschool children enrolled in independently funded childcare centers in Texas, and the lack of understanding of preschool teachers’ response to children’s challenging behavior. The purpose of this basic qualitative study was to explore preschool teachers’ perspective on how they handle children’s challenging behaviors, and what inclines teachers toward suspending or expelling children from independently funded childcare centers. Liu’s theory of children’s externalizing behavior provided the conceptual framework for the study. Ten preschool teachers from urban, independently funded childcare centers in Texas were …

Diagnosing Neurocysticercosis In Skeletonized Human Remains Of Forensic Importance, John O. Obafunwa, Karl Reinhard

Karl Reinhard Publications

Neurocysticercosis is endemic in many parts of the underdeveloped and developing countries, with continuous presence in developed countries due to the influx of migrants from regions where the diseases are endemic. Neuroimaging, anatomic pathological techniques, immunodiagnostic tests, clinical examination and epidemiologic considerations will easily provide the diagnosis. However, physicians in developed countries are perhaps progressively missing the diagnosis, and need to re-acquaint themselves with the condition and acquire a high suspicion index. The authors present a medicolegal case where the forensic team made a conclusion of neurocysticercosis (among other diagnoses), following post mortem examination of a largely skeletonized and mummified …

Exploring The Evolution Of Trypanosoma Cruzi And The Emergence Of Chagas Disease In The Context Of Environmental Change: Applying The Stockholm Paradigm To Archaeoparasitology, Part I, Aida Romera Barbera, Daniel R. Brooks, T. Michael Fink, Karl J. Reinhard

Karl Reinhard Publications

The Stockholm Paradigm is an evolutionary synthesis that explains the emergence of novel pathogens in the context of environmental disturbances. Considering the urgent climate change situation, anticipation stands as key to prevent and mitigate the effects that climate change can have in the emergence of pathogens. However, the success of preventive measures is hindered by a limited knowledge of the interplaying dynamics between biology, environment, and culture leading to emerging infectious diseases. For many decades, bioarchaeologists have been gathering data on past human-environment interactions, therefore contributing to the conversation. Archaeoparasitology, at the intersection between pathology, bioarchaeology, and biology, is uniquely …