Biological Sciences Masters Theses

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Emotion regulation moderates the prospective association between ERN and anxiety in early adolescence: An age-specific moderation of cognitive reappraisal but not expressive suppression
(North Dakota State University, 2024) Tan, Jaron Xe Yung
The increasing prevalence of anxiety problems during adolescence underscores the importance of a better understanding of the development of anxiety. While past research has highlighted a link between error responsivity, indexed by error-related negativity (ERN), and youth anxiety, the role of emotion regulation in the ERN-anxiety relationship remains unclear. We conducted a two-wave study with 115 healthy nine-12-year-olds, and found that expressive suppression (ES), an important emotion regulatory strategy, moderates the ERN-anxiety association. A larger T1 ERN predicted heightened T2 anxiety symptoms in those with higher ES. Interestingly, the moderating effect of cognitive reappraisal (CR), another important emotion regulatory strategy, on the ERN-anxiety association was age-dependent; in older youths, the association between T1 ERN and T2 symptoms was significant only for those with lower CR. These findings offer novel insights into the differential age-related patterns in the moderating effects of emotion regulation, and inform future emotion intervention studies for youths.
Evaluation of Blackbird Damage to Sunflower and the Relationship to Producer Damage Estimates
(North Dakota State University, 2024) Donaldson, Morgan
Sunflower producers face profit losses due to crop depredation by migrating blackbirds (Icteridae). Blackbird damage to sunflower in North Dakota is highly localized, where economic loss to some sunflower fields is severe (loss >20%), others face negligible loss (<5%). To mitigate conflict between producers and blackbirds, an understanding of severity and distribution of bird damage is essential. We investigated blackbird damage to sunflower using estimates collected in the field and estimates gathered from producers through a written survey and direct contact. Damage estimates indicate a state-wide loss of US$10.3-33.5 million. Our comparison of estimates from 2020 indicate that blackbird damage is higher when reported by producers (i.e., survey and direct contact) when compared to infield estimates. The disparity of estimates and unpredictability of bird damage warrants investigation into estimation practices by both biologists (i.e., improved field and survey methods) and farmers (e.g., yield monitors) to achieve accurate estimates of damage.
Influence of Adjacent Uplands and Groundwater on the Hydrology and Invertebrate Community Composition of Seasonal Forest Ponds in North Central Minnesota
(North Dakota State University, 2010) Bischof, Matthew Markus
Seasonal ponds are common throughout northern Minnesota's forested areas. Seasonal ponds typically flood due to snow-melt and high precipitation rates in early spring, then dry by mid-late summer. The dynamic hydroperiods of seasonal ponds create a unique fishless habitat hosting an abundance of many endemic aquatic species. Hydroperiod has long been considered a major controller of biological communities in seasonal ponds, but few data are available for testing hydrological linkages among seasonal ponds, their surrounding watersheds and their resident invertebrate communities. To identify hydrological pond function, I placed peizometers and monitoring wells in 8 sites in the Buena Vista State Forest in Beltrami County, MN, and 8 sites in the Paul Bunyan State Forest in Hubbard County, MN (16 sites total). Water levels were monitored weekly (2006-2009) from spring melt until ponds dried and water tables fell below readable depths. Invertebrate communities were also sampled weekly during 2008 and 2009. Results indicate that high but variable water exchange occurs between seasonal ponds and ground water. Hydrological patterns of seasonal ponds were related to several physical parameters including hydrological function, maximum depth, and canopy cover. Most relationships appear to be consistent between the 2 forest areas; however, some differences are notable, such as soil characteristics and influence of pond surface area on hydroperiod. Patterns in pond invertebrate communities were also related to hydrological function and hydroperiod, and these patterns appear consistent between the 2 forest areas, suggesting that many invertebrates are generalist users of these areas.
Plant Phenological Responses to Climate Change in the Northern Great Plains
(North Dakota State University, 2010) Dunnell, Kelsey Liann
Climate change has been associated with shifts in phenological events which could be disrupting evolved species relationships. The current first flowering times of plants were compared to historical data in the Red River Valley. This gave insight as to what effects climate change is currently having on species in this area. By merging climate variable data from the same time period it was possible to correlate first flowering dates with climate variables for that specific year. Variation in plant flowering times was analyzed over the century to better understand potential ecological consequences of climate change. First flowering times were found to have shifted since previously recorded. The lengthening growing season in the Red River Valley as a result of climate change has resulted in significant shifts in the timing of plant life cycles. The second study used an experimental approach to test the effects of warming on plant species in the tallgrass prairie. Measuring phenological and species composition responses to the temperature changes showed evidence that increasing air temperatures are leading to earlier flowering. There was also a significant increase in species richness. The results of both studies conclude that climate change has the potential to impact the plant community by shifting phenological responses in the tallgrass prairie in the Northern Great Plains.
Investigation of the Nature of Science Views of Undergraduate Natural Science and Nonscience Majors in Biology Courses
(North Dakota State University, 2010) Miller, Marie Christine Desaulniers
Science educators have the common goal of helping students develop scientific literacy, including understanding of the nature of science (NOS). University faculties are challenged with the need to develop informed NOS views in several major student subpopulations, including science majors and nonscience majors. Research into NOS views of undergraduates, particularly science majors, has been limited. In this study, NOS views of undergraduates in introductory environmental science and upper-level animal behavior courses were measured using Likert items and open-ended prompts. Analysis revealed similarities in students' views between the two courses; both populations held a mix of naYve, transitional, and moderately informed views. Comparison of pre- and postcourse mean scores revealed significant changes in NOS viev .. 's only in select aspects of NOS. Student scores on sections addressing six aspects of NOS were significantly different in most cases, showing notably uninformed views of the distinctions between scientific theories and laws. Evidence-based insight into student NOS views can aid in reforming undergraduate science courses and will add to faculty and researcher understanding of the impressions of science held by undergraduates, helping educators improve scientific literacy in future scientists and diverse college graduates.
Environmental Factors Influencing Tumor Associated Pericyte Phenotype in Pancreatic Cancer
(North Dakota State University, 2021) Delgado, Alexander
Pancreatic ductal adenocarcinoma (PDAC) is the third leading cause of cancer death in the U.S. with a 5-year survival rate of 11%. PDAC patients suffer from the lack of effective treatment options largely due to the limited delivery efficacy of the drugs. Tumor vessels are abnormal, leaky, and lack proper pericyte coverage, contributing to elevated hypoxia and interstitial fluid pressure, promoting cancer progression and metastasis, and inhibiting drug delivery efficacy. In the case of PDAC, a large portion of blood vessels were covered by α-smooth muscle actin (αSMA) expressing pericyte, which is normally absent in capillary pericytes. We also showed that PDAC cancer cell-derived exosomes could induce αSMA expression in the pericyte suggesting the pericyte phenotype is influenced by the Tumor Microenvironment (TME). Induced αSMA expression in pericyte disrupted the 3D tube formation efficiency when cultured with endothelial cells suggesting αSMAhigh pericyte confers a pathological feature of tumor blood vessels.
Effects of Processing on Health-Promoting Attributes of Soymilk Phenolics
(North Dakota State University, 2010) Tan, Yingying
This study was designed to investigate the effects of different processing methods on the antioxidant and anti-cancer properties of soymilk crude phenolic extract (CPE) using the human prostate cancer cell line DU 145 as a model system. Four grinding methods and two ultra-high temperature (UHT) processing methods were investigated. Briefly, the four grinding methods included grinding with tap water (Method 1), okara-washed water (Method 2), soaked water (Method 3), as well as both okara-washed water and soaked water (Method 4); the two UHT processing conditions included one-phase UHT (143 °c, 60 s) and two-phase UHT (120 °C, 80 s + 140 °C, 4 s) methods. The antioxidant capability of CPE was measured by oxygen radical absorbance capacity (ORAC) and/or ferric reducing antioxidant power (FRAP) and 2, 2-diphenyl-1-picrylhydrazyl free radical scavenging activity (DPPH) assays. The DU 145 human prostate cancer cell line was sub-cultured in the presence of CPE at various concentrations (0, 1, 2, 4, 8 mg/ml) for 48 h and the percentage of cell viability was evaluated by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay and/or flow cytometric analysis with carboxyfluorescein succinimidyl ester (CFSE) staining. An induction of apoptosis was detected by flow cytometric analysis with annexin V/ propidium iodide (Pl) double staining, morphological change observation with acridine orange/ethidium bromide (AO/EB) double staining, and Western blot assay of apoptotic proteins. The results showed that grinding Method 4 and the two-phase UHT method exhibited greater total phenolic content and antioxidant capability than the other three grinding methods and one-phase UHT, respectively. In addition, soymilk CPE inhibited cell proliferation in a dose-dependent manner and upon purification. The anti-proliferation effects observed in soymilk CPE were associated with the apoptosis induction in DU 145 cell line as evidenced by morphological changes and the expression of apoptotic proteins. These results suggest that the soymilk CPE plays an important role in anti-proliferation, and apoptotic properties of soy in DU 145 cells. Furthermore, these health-promoting properties were affected by processing conditions, such as grinding and thermal conditions. The results of this study benefit the soy product industry to select appropriate processing conditions to retain more health-promotion phytochemicals during soy food's processing.
Matrix Metalloproteinase Expression Varies Throughout Development and During the Innate Immune Response of Tobacco Hornworm. Manduca sexta
(North Dakota State University, 2010) Vishnuvardhan, Smitha
Matrix metalloproteinases (MI'v1Ps) are a family of conserved, proteolytic enzymes. MMPs can degrade most extracellular matrix proteins. As such, they are key enzymes in tissue remodeling processes. such as molting and metamorphosis in insects. The presence of MMP in tracheae of 4th and 5th instar Manduca scxra (M sexta) larvae was investigated using zymograms and Western blots, and the expression was found to decrease at the end of the instar. Failure to completely inhibit gelatinolytic activity in a zymogram indicates the existence of various other proteases that arc involved in the molting process. However, delay in the appearance of the dorsal blood vessel along with a reduction in the body mass upon inhibition of MMP supports our hypothesis that MMPs are required for molting. MMPs are also known to be up-regulated in many disease states, where they may cause tissue damage. Their presence may be beneficial, as their inhibition may result in worsening of symptoms or increased mortality. We tested the hypothesis that MMPs play a role in innate immunity in the tobacco hornworm caterpillar. Jf. sex/a. Larvae infected with E. coli DH5a had significantly more circulating hemocytes (insect blood cells) when compared to the larvae v,:hich received an MMP inhibitor. suggesting that MMPs may be important for hernocyte recruitment from the hematopoietic organs such as the lymph gland and hematopoictic cells present near the v.'ing imaginal discs. The expression of MMP was increased by 50% in larvae that had been infected with E. coli DH5a. However, this response was abrogated upon inhibition of MMPs. reducing expression tocontrol levels. The majority of the circulating hemocytes were granulocytes. a cell type that phagocytoses foreign bodies. including pathogens. We used flow cytometry to assess phagocytic ability. Hemocytes in the presence of the MMP inhibitor were less abk to phagocytose sephadex beads. supporting the hypothesis that this MMP contributes to the cellular innate immune response. Our results suggest that MMP expression is high at the beginning of the in star while it reduces as the caterpillar reaches molting. during which other proteases like chitinases and molting fluid proteinases play a more prominent role. Our results also suggest that M. sex/a larvae have a reduced immunity to bacterial infections when MMPs are inhibited. Collectively, inhibition of MMPs during the molting process indicates that the larvae. by down regulating the expression of MMPs. prevent the elicitation of immune responses that is generally seen during the larval pupal metamorphosis.
Long-Term Monitoring of Bat Populations in North Dakota
(North Dakota State University, 2022) Krueger, Derek
Throughout the past few decades, North American bat species have experienced population declines due to White-Nose Syndrome, wind energy, climate change, and other factors. In North Dakota, the presence of wind energy, and the recent arrival of White-Nose Syndrome in 2019, pose serious threats to bat populations in the state. The objective of this study was to gather and analyze long term population data on the different bat species in North Dakota. In Summers of 2019-2021, we recorded bat echolocation call sequences at 60 grid cells established across North Dakota. We compared data across years to determine if any species showed changes in activity level. Occupancy modeling was also used to determine any link between occupancy/detectability and some environmental features for four bat species in 2020. Our results suggest a possible decline in regional populations of species in the Myotis genus. We found no link between occupancy and environmental factors.
Energetics of Interrupted Development in Megachile rotundata
(North Dakota State University, 2022) Walter, Rikki
Insects in temperate regions may experience temperature fluctuations during springtime development which can lead to low temperature stress. Previous research has shown that short artificial fluctuations in temperature during interrupted development are advantageous when compared to static temperatures, but it is unclear why. One idea is it allows insects to repair chill injury and maintain cellular membrane potential. My goal was to understand what macromolecules are maintaining ion balance through measuring the respiratory quotient (RQ), trehalose, glycogen, simple sugars, and lipids using biochemical assays. The development of Megachile rotundata was stimulated for two weeks before interrupting with either fluctuating or static temperature regimes. RQ was measured repeatedly over two weeks and subsets of bees from each treatment were frozen at the same time points for biochemical analyses. The RQ varied over time and lipids and trehalose had the biggest differences between static and fluctuating temperatures as well as over time.
The Effects of Variation in Temperature and Parental Behavior on Offspring Body Mass, Telomeres and Survival Are Context-Dependent in Free Living House Sparrows (Passer domesticus)
(North Dakota State University, 2022) Dennis, Abigail
Although developing birds are vulnerable to extreme and erratic temperature conditions associated with climate change, parents have some ability to buffer these effects via incubation and postnatal behavior. However, parents are constrained by their own physiology and ecology. In this thesis, I sought to determine which factors (seasonal thermal profile, consistency of ambient temperature and/or parental behavior) drove traits linked to fitness across ontogeny in free-living house sparrow nestlings (Passer domesticus). I found that the effects of these factors were context-dependent; seasonal thermal profile and average temperature were important in shaping body size across ontogeny, but variance in nest temperature and female postnatal visits better predicted hatching and day 10 survival, respectively. Future studies should seek to answer these questions in other populations and explore hypotheses surrounding interactions between developmental environments to better our understanding of climate change and thermoregulation in response to increasingly warm and erratic global temperatures.
Establishing and Characterizing Patient-Derived Breast Cancer Cell Lines
(North Dakota State University, 2022) Mohammadi, Farid Solaymani
Commercial cancer cell lines have long been extensively used as an important platform to study cancer. They have contributed to a plethora of discoveries in the field of cancer research. However, there are limitations with using these cell lines, such as induced mutations over the long-term in vitro culture. These mutations cause incorrect exhibition of the in vivo characteristics of the cancer cells. Here, we focused on establishing Patient-derived breast cancer cell lines and attempted to characterize them in terms of several biomarkers that are shown to be overexpressed in breast cancer cells. Patient-derived breast cancer cell lines are more reliable tools to study the molecular and cellular processes taking place in vivo, since they are freshly isolated from the tumor biopsy and do not undergo induced immortalization. We explored the CK19, Ki67, vimentin, EpCAM, E-cadherin, and N-cadherin expression in three successfully established patient-derived breast cancer cell lines.
Assessment of Blackbird Damage to Sunflower and Corn Fields in the Prairie Pothole Region of North Dakota
(North Dakota State University, 2011) Klosterman, Megan Elise
North Dakota is the top sunflower producing state in the United States, annually harvesting about 405,000 ha (1 million acres). Up to 63% of this crop is grown in central North Dakota in an area known as the Prairie Pothole Region (PPR). Since the early 2000s, com also has become a major crop in the PPR due to the development of hybrids for northern crop areas and increases in com prices. Blackbirds (Icteridae) can cause significant damage to both ripening com and sunflower. It has been three decades since a comprehensive sunflower damage survey was conducted in the PPR. I assessed blackbird damage to ripening sunflower and com in 120 randomly-selected plots during three growing seasons, 2008-2010. Damage was analyzed across four strata (Northeast Drift Plains, Northwest Drift Plains, Southern Drift Plains and Missouri Coteau) within the PPR. Landcover was analyzed to determine possible variables (pasture, com, sunflower, open water, wetland, small grains, developed, wooded, beans and other) related to blackbird damage. Stepwise logistic regressions were performed along with AIC model selection to determine significant (p<0.1) independent variables related to sunflower and com damage. Average damage to sunflower (2.14%) was higher than damage to com (0.33%), with sunflower in the Southern Drift Plains having the greatest levels of damage (11.11 %). Beans and wetland showed the greatest significance in relation to sunflower damage (p=<0.001, p=0.035), according to the selected AIC model. The most significant landcover variables surrounding damaged corn fields was open water (p=0.022), showing an increase in damage, and pasture (p=0.056), showing a decrease in damage. The results of this study provide data to help producers make informed decisions about crop selection and location.
Rural Youth's Enrollment in a Stem Summer Camp: A Comparison Between In-Person and Take-Home Experiences
(North Dakota State University, 2021) Milbrath, Madison Rena
The utilization of informal STEM education opportunities has been well established as a way to supplement and support formal STEM education learning. Many of the studies confirming this were completed in urban settings. Recently there have been calls to better our understanding of rural populations and their interactions with informal STEM education. This study analyzed the registration records of youth in an informal STEM education experience as well as survey responses from the youths’ parents/guardians. This was done in an attempt to understand if rurality impacts participation in an in-person STEM education experience compared to a take-home STEM education experience. Additional work looking at survey responses attempted to find other predictors or indicators that could be reasons for participation associated with rural populations.
Foraging Strategies and Morphometric Characteristics of Bats in North and South Dakota
(North Dakota State University, 2021) Karevold, Hanna Marie
Insectivorous bats are an important group for studying links between dietary flexibility and associated impacts on foraging and morphology of individuals from different populations. Since different habitats generally have unique insect communities, populations across a species range will likely be adapted for most effective foraging within their local environment. I aim to 1) investigate the diets and associated foraging strategies of the eleven bat species found in North and South Dakota and 2) examine the morphological characteristics of Eptesicus fuscus (Big brown bat), Myotis lucifugus (Little brown bat), and Myotis septentrionalis (Northern long-eared bat). I predicted that 1) interspecific variation in foraging strategies would exist due to morphological variation and 2) any intraspecific variation in foraging strategies would correlate with population-level differences found in morphological characteristics. Understanding population-level differences can provide managers with critical information, keying in on the protection of resources that are important to local bat populations.
Influence of Habitat Characteristics on Amphibian Stress and Reproductive Success in North Dakota
(North Dakota State University, 2021) Jones, Rebecca Lynn
As amphibians continue to decline, conservation efforts are a necessity in management plans. It is essential to determine the correlation between water characteristics, stress, and habitat alteration with anuran losses. Large portions of diverse wetlands across the state of North Dakota are being lost to agriculture at unprecedented rates and as a result, habitat for anurans is declining. Larval and visual encounter surveys were conducted to distinguish the essential habitat characteristics that are crucial during each stage of amphibian reproduction. In addition to collection of amphibian data, macro-and micro-habitat data were recorded at each site. Captured individuals had their blood drawn and water-borne corticosterone samples collected to assess this environmental stress. This study found that surrounding developed area impacts larval suitability of a habitat and stress levels. It provides an updated suitability model and baseline levels of corticosterone and white cell profiles for a native anuran species.
Faculty Intention and Faculty Implementation - Do They Align?
(North Dakota State University, 2021) Paulson, Laura Ann
There have been a multitude of calls to reform teaching in undergraduate education. The implementation of active learning in the classroom increases student learning, relative to traditional lecturing. I worked with university faculty to determine the relationship between their interest in (intent) and application of active learning (behavior). I measured the intent of faculty to implement active learning and conducted classroom observations. Based on these classroom, observations, I found there is not always an alignment between an individual’s intent and behavior. Therefore, interviews were conducted to determine what factors could be contributing to the misalignment. Several factors were found: preparation time of new activities, classroom setup/layout, and the student population. Understanding what factors impact the change from traditional teaching to active learning teaching creates an opportunity to provide faculty with remedies such factors.
An Evaluation of the Social Perceptions and Biological Efficacy of Unmanned Aircraft Systems for Avian-Agriculture Conflict
(North Dakota State University, 2021) White, Mallory Gyovai
North Dakota sunflower producers face a dilemma when it comes to blackbirds (Icteridae). Migrating flocks produce localized damage to production, which results in some farmers with no bird issues, while others face total economic losses. A dynamic and humane crop protection tool is necessary to reduce blackbird damage in this broad-scale agriculture setting, as damage is actively occurring, while considering the protected status of blackbirds. This study examined a novel tool, unmanned aircraft systems (hereafter, UAS), through the lens of a social evaluation of farmers’ opinions and the biological impact on blackbird flock behavior. Farmers were very willing to allow a variety of UAS operations on their property, but willingness was dependent on age, farming generation, prior blackbird damage and preventative efforts. Time of day and flock size were important factors for perception of risk toward UAS by blackbird flocks, and 52% of the flocks abandoned due to UAS hazing.
Effects of nest site environment and timing of breeding on reproductive success in Franklin's gulls (Larus pipixcan)
(North Dakota State University, 2009) Berg, Emily Anne
Offspring performance and phenotype are affected by genotype and environment, which in birds includes yolk resources (part of the embryonic environment). Female colony nesting birds may influence offspring competitive ability in the post-hatching nest site environment by differentially allocating yolk resources to eggs based on nest site characteristics. Offspring performance may also be linked to prenatal allocation of resources, as well as post-natal parental care. Nest site characteristics, including nest size, density, and timing of breeding, influence the behavior (e.g., aggressive, social) and resource acquisition of the parents, as well as provide measureable variation in the postnatal environment. I used an experimental approach to quantify relationships among nest site characteristics, nest success, and offspring performance (growth and survival) in a nesting colony of Franklin's gull (Larus pipixcan). I also used a cross-foster experiment to examine tbe effects of parental care and provisioning on growth and survival of neonates. Timing of breeding, egg quality, chick quality, nest success and chick survival varied between the 2006 and 2007 cohorts. Nests in 2006 were initiated later than nests in 2007 and experienced lower nest survival rates but produced chicks in better condition. Chicks in 2006 also experienced higher survival than chicks in 2007; however, chicks in 2006 experienced slower growth. Timing of breeding may have influenced measures of nest and chick success examined in this study. In Franklin's gull, a trade-off between offspring quality and offspring quantity may be a consequence of migratory delays or unusual weather patterns in this long-distance migratory species.
Aging and Early Life Stress: Telomerase Dynamics and The Consequences for Telomeres in a Wild Bird
(North Dakota State University, 2020) Vangorder-Braid, Jennifer Teresa
Aging is an underlying risk factor for many major diseases including cancer, cardiovascular disease, and neurodegeneration. Yet we still do not know the full extent of how our bodies age and what determines our lifespan. One mechanism that may play an important role are telomeres, which are protective caps at the end of chromosomes. Telomeres are directly linked to longevity and can be lengthened by the enzyme telomerase. Early life telomere length is critical for lifespan, but we do not know how telomerase performs during this period. Whether variation in telomerase levels can influence telomere length and loss during development with consequences to longevity is still unknown. This thesis focuses on the role of telomerase during post-natal development and its response to stressors and activators with effects on telomeres. Taken together this research enhances our understanding of how telomerase acts and influences telomere during post-natal development.

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