2020 Abstracts

Jones, Gerald; Zhao, Jia; Ellis, Dylan; Sims, Ronald (Utah State University)
Faculty Advisor: Zhao, Jia (College of Science, Mathematics and Statistics Department); Sims, Donald (College of Engineering, Biological Engineering Department)

Algal blooms are a worsening issue across the United States. Algal blooms are formed by an overabundance of nutrients in the water such as Nitrogen and Phosphorus. To combat this, Utah State University is collaborating with the Central Valley Water Reclamation Center, the largest water treatment plant in Utah, with innovating ways to reduce Nitrogen and Phosphorus levels in wastewater before being discharged into the local bodies of water.

One process shows promise. The Rotating Algae Biofilm Reactor (RABR) consists of an attached biofilm growth that rotates through a growth substrate. As the biofilm grows, it assimilates the nutrients in the water, thereby transferring them from the water into the biofilm algae.

No referred literature exists on mathematically connecting RABR biofilm productivity with actual data. The purpose of this research is to formulate a model of the mass production of the RABR as a function of sunlight and rate of exposure. This process is done by combining an analytical and data-driven approach to discover the equation. Sparse Identification of Nonlinear Dynamics (SINDy) is a data-driven approach that represents a potential breakthrough in being able to identify and quantify the most important parameters influencing algae biofilm yield and productivity. This study will go through the process of creating an analytical model and then scrutinizing said model with real data and make necessary adjustments.

An analytical model using Bara and Bonneford's work on photoinhibition is provided as a baseline for this study. Some data-driven results will also be presented to address the fundamental characteristics of biofilm growth.

The biofilm harvested from the RABR has significant potential for bioproducts such as biofuel, medicine, bioplastics, and livestock feed. Across different industries, this robust model describing algae biofilm growth will provide a mathematical foundation for future algae-based biofilm technologies.

Esplin, Rylee: Chellamuthu, Vinodh (Dixie State University)
Faculty Advisor: Chellamuthu, Vinodh (Dixie State University, Mathematics)

The Zika Virus (ZIKV) is a mosquito-borne disease that inhabits Aedes Aegypti mosquitoes. This disease can be passed to humans three different ways: first, through the bite of an infected mosquito; second, sexual transmission between humans who are already infected with the disease; and finally, from humans to their unborn children through vertical transmission. Several studies have shown the dynamics of ZIKV and its dependency on temperature. We developed a temperature-dependent mathematical model using systems of first order differential equations to analyze the spread of the ZIKV in an effort to control the mosquito population. Our model explicitly incorporates the temperature dependency of the vital rates of the mosquito population. Furthermore, our model will also take into account the local environmental data to show the effects of seasonality within the transmission of ZIKV. Our simulation results show the importance of temperature and its impact on the mosquito-human interaction.

Geist, Claudia; Collins, Saffron (University of Utah)
Faculty Advisor: Geist, Claudia (Social and Behavioral Sciences, Sociology)

Unplanned pregnancies can have negative effects, especially in poor communities. There is little research about the perceived impact of a hypothetical pregnancy. Understanding individuals' ideas about how unplanned pregnancies might affect their lives will help us understand contraceptive behavior and ideas about family formation.

We explore the perceived impact of a hypothetical pregnancy among individuals who participated in the HER Salt Lake Contraceptive Initiative (Sanders et al., 2018). We coded 800 responses to the question "Please tell us a bit more about how a pregnancy now or in the next few weeks would affect your life." A desire to avoid pregnancy for the next year was an enrollment criterium, so most participants had negative feelings about a hypothetical pregnancy. However, we found that the kind of anticipated impact varied.

The most common response was a worry about financial resources (30.6%), followed by educational goals (20.4%): "It would stop my plans of going to graduate school and hurt my financial situation greatly. It would hurt my current relationships with partners and family and would be very emotionally and physically stressful." "Pregnancy now would rock my world. I am a single mom of 2 toddlers who's going to school part time and working part time. If I were to become pregnant now or in the next few weeks I wouldn't be able to accomplish the goals that I have set for myself." About 16.9% of participants mentioned negative impact without being specific. However, 5.4% of the respondents reported positive thoughts about a hypothetical pregnancy.

Our study may help scholars and medical providers get a better understanding of the precursors of decision-making processes for contraception and family planning. It will also illustrate where individuals faced with an unplanned pregnancy may need support.

West, Noelle; Chellamuthu, Vinodh (Dixie State University)
Faculty Advisor: Chellamuthu, Vinodh (Dixie State University, Mathematics)

West Nile Virus (WNV) is a vector-borne illness that has circulated among birds, eventually spreading across the globe. This disease has resulted in thousands of infections and deaths. Several studies suggest that passive immunity in birds and vertical transmission in mosquitoes play a crucial role in the spread of the disease. We have developed a mathematical model to investigate the effects of passive immunity and vertical transmission within the disease dynamics. Our simulation results suggest that passive immunity increases bird resistivity to WNV and that vertical transmission among mosquitoes increases the spread of WNV. Moreover, we expect this model to be used by mosquito abatement centers to estimate the populations of immune birds and to simulate disease outbreaks in the local community.

Dallon, John; Neubert, Nathaniel; Evans, Emily (Brigham Young University)
Faculty Advisor: Dallon, John (Brigham Young University, Mathematics); Evans, Emily Brigham Young University, Mathematics)

The organization of collagen fibers within the various connective tissues of the body plays an important role in the functionality of the organs they support. While the biochemical composition of collagen lattices is largely understood, it is difficult to study how the microstructural organization of collagen affects the macroscopic tissue properties. In this project we computationally stretch stochastically generated lattices consisting of nodes joined by spring like connections representing the fibers of a collagen lattice to examine how varied nodal connectivity, fiber length and fiber orientation affect the Young's Modulus of the lattice. This information will aid biologists in the production of synthetic lattices by providing a guideline of parameters that are most important to control in the creation of lattices with specific desired properties. This in turn will provide insights into bioengineering, wound care and other medical sciences.

Desdames, Chloe; Smith, Mick (Salt Lake Community College)
Faculty Advisor: Seaboch, Melissa (Salt Lake Community College, Anthropology)

Spider monkeys (genus Ateles) is one of the many endangered species in Costa Rica and they can now only be found in very few places due to deforestation. It is important for conservation reasons to know what forest types spider monkeys prefer. According to prior research in Surinam, Mexico, and Bolivia, Ateles prefers primary forests (undisturbed, high canopy) over secondary forests (degraded, lower canopy). Ateles are frugivores and their habitat preference depends highly on fruit availability. Fruit is more abundant in primary over secondary forests. This goal of this study was to determine whether spider monkeys in Costa Rica have a similar habitat preference. I hypothesize that spider monkeys will be found more often in high canopy primary forests compared to secondary forests. This research was conducted at La Selva Biological Station in northeastern Costa Rica. La Selva is a protected lowland tropical rainforest consisting of both primary forest (55%) and secondary forest in various stages of regeneration. I conducted a census of Ateles geoffroyi by walking established trails, with markers every 50 meters, in May 2019. Whenever a spider monkey was spotted, the trail name, nearest meter marker, and forest type were recorded. On a census of 9 trails, five Ateles groups were located, with four of the sightings being in primary forests. My hypothesis, that Ateles geoffroyi would be found in primary over secondary forests, was supported because 80% of the sightings were in primary forests. This is especially significant because, of the 20.5 kilometers censused, only 4.6 km censused (22%) were in primary forests with the remaining 15.9 km (78%) in secondary forests. This preference for primary forests agrees with prior studies on Ateles in other Neotropical forests. This highlights the importance of conserving primary forest for the well-being of spider monkeys.

Hansen, Wade; Stockard, Alyssa; Anderson, Elizabeth; Yorgason, Jordan; Sudweeks, Sterling; Wu, Jie; Steffensen, Scott (Brigham Young University)
Faculty Advisor: Steffensen, Scott (Family, Home, and Social Sciences; Psychology); Yorgason, Jordan (Life Sciences, Physiology & Developmental Biology); Sudweeks, Sterling (Life Sciences, Physiology & Developmental Biology)

The prevailing view is that enhancement of dopamine (DA) transmission in the mesolimbic underlies the rewarding properties of ethanol (EtOH) and nicotine (NIC). Although the dogma is that EtOH enhancement of DA neural activity contributes to enhancement of DA transmission, DA neurons are not sensitive to rewarding levels of EtOH. However, VTA GABA neurons are sensitive to low-dose EtOH. We have shown previously that EtOH modulation of DA release in the NAc is mediated by α6-containing nicotinic receptors (α6*-nAChRs), that α6*-nAChRs mediate low-dose EtOH effects on VTA GABA neurons and EtOH preference, and α6*-nAChRs may be a molecular target for low-dose EtOH. The aim of this study was to evaluate EtOH effects on VTA GABAergic input to CINs and DA release in the NAc. Using DIO channel rhodopsin-2 (ChR2) viral injections into the VTA of VGAT Cre mice, we found that VTA GABA neurons send an inhibitory projection to CINs, replicating what has been demonstrated by others. Low-dose EtOH (IC50 = 10 mM) decreased optically-evoked IPSCs (oIPSCs) on CINs and enhanced (EC50 = 10 mM) CIN-mediated spontaneous DA release. Surprisingly, oIPSCs on CINs were not blocked by typical GABAA receptor (GABAAR) antagonists, but by GABAR rho-1 antagonists, suggesting involvement of atypical GABARs on CINs that are postsynaptic to VTA GABAergic input. The α6-conotoxin MII blocked the effects of EtOH on spontaneous DA release and optically-evoked DA release in choline acetyltransferase (ChAT) ChR2 mice. Chronic administration of NIC enhanced EtOH consumption in the drink-in-the-dark procedure and EtOH preference in the CPP procedure and concomitantly enhanced expression of α6*-nAChRs in VTA GABA neurons, without affecting other nAChR subunits. Taken together, these findings suggest that VTA GABA neuron inhibitory input to CINs is modulated by α6*-nAChRs and sensitive to low-dose EtOH, which may underlie the rewarding properties of EtOH.

Allen, Sierra; Meyer-Ficca, Mirella; Wandersee, Miles (Utah State University)
Faculty Advisor: Meyer-Ficca, Mirella (College of Agriculture and Applied Sciences; Animal, Dairy, and Veterinary Sciences Department)

Niacin, a component of vitamin B3, is necessary for the synthesis of nicotinamide adenine dinucleotide (NAD+). NAD+ is an essential coenzyme in several metabolic processes, including those that regulate glucose and fat homeostasis in the body. Niacin is available to humans in its dietary form through foods such as meat, various legumes, nuts and vegetables. Niacin deficiency has been linked to health problems including age-related decline of cognitive abilities, as seen in Alzheimer's disease, and impaired dermal repair. In cases of extreme niacin deficiency, individuals may even develop pellagra, a disease characterized by dermatitis, diarrhea and dementia. Recent studies in niacin deficient mice indicate that niacin deficiency impairs proper glucose metabolism. Compared to mice with adequate niacin levels, niacin deficient mice experience a significant loss of total body weight and body fat and have impaired glucose regulation in response to insulin. We hypothesize that these metabolic defects result from inadequate levels of NAD+ preventing the conversion of lactate to pyruvate in the gluconeogenesis pathway, which in turn results in decreased blood glucose levels. Another potential explanation is that niacin deficiency results in decreased glycogen stores in the liver, also impeding glucose production. To test these hypotheses, we are studying the relationship between dietary niacin and glucose metabolism in a transgenic mouse model with acquired niacin dependency that accurately represents human niacin metabolism. Results of this study will contribute to better understanding of niacin's role in proper glucose metabolism, with important implications for diabetes and other glucose-related diseases, particularly in populations with limited access to quality food.

Garg, Varun (University of Utah)
Faculty Advisor: Balagurunathan, Kuberan (University of Utah, College of Pharmacy; Medicinal Chemistry)

Heparin is a widely-used blood anticoagulant medicine that is used in surgeries and in treatment of circulatory system illnesses. Heparin is currently harvested from live pigs before they are slaughtered. There are many problems with the current production process of heparin. On a chemical level, the drug can be easily and accidentally altered due to its complex chemical nature. In addition, the environmental impact of the pigs that need to be raised on farms and fed is immense. These reasons and more are why bioengineering approaches towards the artificial synthesis of Heparin need to be researched. One of the major obstacles in the synthesis of heparin is the production of Low Molecular Weight (LMW) Heparosan, a chemical precursor. The research goal is to find methods to increase LMW Heparosan yields to a point where those same yields can be used to conduct further exploration into Heparosan oligosaccharide precursors. These oligosaccharides are useful in further understanding heparin structure-function relationships and will eventually help in the goal to find a commercially viable, cost and time effective method of heparin production. Using shake flask bacterial cultures, LMW Heparosan was produced while adjusting variables such as bacterial density at induction and incubation time to maximize yield. Once a sufficient yield was obtained, oligosaccharide structures spliced from the LMW Heparosan were classified for further research. The initial shake flask experiments showed increased yield and purity of Heparosan for each successive trial. Further work is required to scale up production of LMW Heparosan to a mass-market synthetic Heparin but the research conducted shows a promising method to synthesize and improve yields to make that possible.

Bonnie K. Baxter (Westminster College)
Faculty Advisor: Baxter, Bonnie (Westminster College, Biology)

Gypsum is a calcium sulfate mineral in a hydrated form. NASA's Mars Exploration Rover, Opportunity, found veins of gypsum deposited by water in 2011(Figure 7), and gypsum has been detected on Mars as early as 2005 by the ESA's Mars Express Orbiter. On Earth, gypsum is formed in hypersaline environments, in minerals left behind when water evaporates and it can trap microorganisms in fluid inclusions. Gypsum obtained from Great Salt Lake was used to develop a method to extract halophilic archaea and culture it in the lab. Our studies show that the mineral was difficult to dissolve in aqueous microbiological media. We tested various methods of dissolution involving mechanical crushing and tested solvents including microbiological media. We also employed a variety of cultivation methods. We will present data on best practices for obtaining halophilic microorganisms from gypsum samples. The method obtained could be used to isolate potential microorganisms present in gypsum samples from Mars.

Clarke, Eliza; Williams, Stephanie; Payne, Andrew; Obray, J Daniel; Yorgason, Jordan; Steffensen, Scott (Brigham Young University)
Faculty Advisor: Steffensen, Scott (Family, Home, and Social Sciences; Psychology)

Dopamine (DA) transmission is a key player in the rewarding aspects of ethanol as well as ethanol dependence. The current dogma is that DA transmission is increased during ethanol exposure via the inhibition of ventral tegmental area (VTA) GABA neurons and that excitation of VTA GABA neurons during withdrawal results in decreased DA transmission. Microglia, the major neuroimmune effector in the brain, may be a key mediator in this process by releasing cytokines following activation. It is also thought that BDNF may mediate this effect. We evaluated the effect of ethanol on cytokine concentrations in the VTA and nucleus accumbens (NAc), and found that low dose ethanol (1.0 g/kg) decreased interleukin (IL)-10 levels, but high dose ethanol (4.0 g/kg) increased IL-10 levels. We also used standard cell-attached mode electrophysiological techniques to evaluate the effects of select cytokines and BDNF on VTA neuron firing rate in vitro. We found no change in firing rate in response to IL-6 and BDNF, but an increase in firing rate in VTA DA neurons in response to IL-10. Consistent with the changes in firing rate, optically-evoked IPSCs were also found to be decreased in response to IL-10. Ex vivo voltammetry and in vivo microdialysis were done to determine whether IL-10 can directly result in an increase in DA release. Although ex vivo voltammetry showed no change in DA release, IL-10 increased DA release in vivo. These findings suggest that the rewarding and/or addictive effects of ethanol may be mediated by cytokines, specifically the anti-inflammatory cytokine IL-10.

Marchant, Nathan; Marchant Erik; Elison, Weston; Herring, Jacob; Yang, Haokun; Tessem, Jeffrey; Hancock, Chad (Brigham Young University)
Faculty Advisor: Hancock, Chad (Brigham Young University; Nutrition, Dietetics, and Food Science); Tessem, Jeffrey (Brigham Young University; Nutrition, Dietetics, and Food Science)

Purpose: To analyze the effect of the Nr4a3 gene on respiratory capacity of mitochondria in skeletal muscle of mice on a normal or high fat diet.

Methods: Nr4a3-/- and WT mice were fed a normal chow (NC) or high fat diet (HF) for at least 20 weeks. After euthanasia, soleus muscle was harvested and wet weight was measured and prepared for respirometry. Mitochondrial respiration was evaluated using an Oroboros Oxygraph Respirometer. Respiratory capacity comparisons were made with a two-way ANOVA and Tukey multiple comparison test.

Results: Oxygen consumption is reported as pmol/(s*mg wet tissue) and statistics are represented as mean ± SEM. In the WT male mice there was a decrease in coupled complex I supported respiration in HF vs. NC diet (25.9 ± 7.3 vs. 64.5 ± 5.0, p=0.004). In the HF WT group there was also a decrease in uncoupled respiration (61.4 ± 15.0 vs. 107.8 ± 7.1, p=0.0004) compared to NC WT. In female mice there was also a decrease between HF WT and NC WT in complex I (28.2 ± 3.7 vs. 57.4 ± 5.7, p=0.0005) and uncoupled respiration (87.1 ± 7.1 vs. 119.4 ± 8.9, p=0.0001). However, there was no significant difference between the WT NC mice and either of the Nr4a3-/- groups. Coupled complex I and uncoupled respiration states in both Nr4a3-/- groups were not significantly different from WT.

Conclusion: Feeding mice a high fat diet impairs proper mitochondrial function in muscle when compared to a normal chow diet. The decrease in respiration from the HF diet is dependent upon the function of the Nr4a3 gene, as no decrease was observed in Nr4a3-/- mice.

Errigo, Isabella; Abbott, Benjamin; Reimer, Jessica; Glenn, Jeff; Chaney, Robert; Freeman, Andrew; Frei, Rebecca; Howe, Peter, Mendoza, Daniel; Kelly, Kerry; Summers, Laura; Johnston, James; Carter, Thom; Bratsman, Samuel; Stacey, Audrey; Wilson, Derrek; Lange, Leslie (Brigham Young University)
Faculty Advisor: Abbott, Benjamin (Life Sciences, Plant and Wildlife Sciences)

Recent medical and economic research has found that air pollution causes much more damage to our health and economy than previously understood. Globally, 16% of all deaths are attributable to air pollution—15 times more than from all wars and other forms of violence. However, translating these research findings into policy and behavior change at local levels remains a major challenge, partially because of mismatch between the spatial scale of the air pollution research (often national or global) and governance frameworks (typically multi-scale from local to regional). Here, we tested the effectiveness of expert assessment as a tool to resolve research-policy mismatch. We distributed a questionnaire to over 80 researchers living in Utah, asking for quantitative estimates of human health and economic costs of air pollution, and recommendations for what policy actions would be most effective at reducing those costs. Expert responses of air pollution costs varied widely, but were consistently higher than recent public health studies, indicating that experts were including a more complete suite of factors, or that they were biased. We discuss the response of Utah policymakers to these results and present a framework of involving local researchers to increase the assimilation of data into decision making.

Edvalson, Logan; Davis, Morgan; Busath, David (Brigham Young University)
Faculty Advisor: Busath, David (Life Sciences, Physiology & Developmental Biology)

A significant research focus in influenza pathogenesis has been directed towards growth factor receptor tyrosine kinases (RTKs) and their respective phosphorylation cascades. Several recent studies have implicated RTK signaling cascades, that are classically associated with cancer, with increased viral titer. A portion of these studies have focused on early segments of the signaling cascade while others' efforts focus in the late segments. Experiments performed in our lab have identified two receptor pathways—PDGF and VEGF—that, when the receptor inhibited, reduces the efficiency of the influenza virus. These data were achieved using compounds, and variants of compounds, already approved for human use in cancer. Although the drug oseltamivir is already approved for influenza treatment, there is concern for the development of viral drug resistance. The introduction of several types of infection blockers similar to the ones identified by our, and others, laboratories can mitigate viral resistance; like the introduction of several types of antibiotics has reduced bacterial resistance. We hypothesize that these pathways work in multiple parts of the infection cycle ranging from viral endocytosis to the budding off of new virions. Experiments are now under way to determine the specific interactions in these pathways that are important in the viral life cycle.

Stoner, David; Clark, Debbie; Bufton, Ali (Utah State University)
Faculty Advisor: Stoner, David (S.J. & Jessie E. Quinney College of Natural Resources, Wildland Resources Department)

A challenge facing Utah mule deer is habitats with older shrubs and little to no regeneration of young plants, or habitats being replaced with cheatgrass (Bromus tectorum)—both in critical winter ranges. Forested habitats provide cover but when there is little understory, there isn't enough forage. Hunting funds the management of big game animals. If there is inadequate funding, there will not be funding for habitat. Thus population objectives will not be met. Mule deer (Odocoileus hemionus) may alter activity schedule during the hunting season by selecting restricted hunter access areas, including agricultural lands. Here we test the hypothesis that deer alter activity schedules in space (accessible and WILD sites) and time in response to human presence. We defined WILD as being further than 100 meters away from a human or OHV trail, or road. Our research question asks if accessible roads have an effect on mule deer activity schedule in response to hunting pressure, as indexed by access differences. We predicted that increased human activity during the hunting season would cause reduced deer activity during daylight. We expect more deer detections in September, less in October (hunting season), and an increase in November during the rut. Spatially we expect higher buck detection rates in remote areas, with no change in activity schedule, or are active in the day. The study area is in the Bear River Range east of Logan, Utah. We are using Before-After-Control-Impact (BACI) Sampling Design. We used camera trap data from October 2017 through December 2017 to measure (1) detection rates of bucks (photos/camera-day), and (2) activity times (diurnal, crepuscular, or nocturnal) by sex-age class. We controlled for habitat type by grouping cameras within common elevation bands and plant communities. Reduced hunter success may result in decreased hunting interest with economic implications for mule deer conservation.

Johnson, Erik; Johnson, Ellie; Johnson; Jerald (Brigham Young University)
Faculty Advisor: Johnson, Jerald (Brigham Young University, Biology)

It seems counterintuitive that organisms should evolve handedness (or what we might more broadly refer to as "lateralization"). Individuals who can forage equally well with both hands, who can kick equally well with both feet, who can detect stimuli and orient equally well in both directions, and so on—these individuals should be favored relative to those who are either right handed or left handed. Yet in humans, and in several other species, handedness is common, but we still no very little about why. Here we explore this question using a tropical freshwater fish species with an unusual anatomy. Males have a modified fin—the gonopodium—that they use to internally inseminate females. Interestingly, males are either right or left handed for this structure, which terminates with either a dextral or sinistral twist. In this study, we ask a simple question: is there a link between male gonopodium morphology and male behavioral lateralization. We use a detour test approach to determine how males approach different stimuli, turning either to the left or right to more clearly see each type of stimulus. We focus on how males approach potential mates, predators, and novel items. We predict that males with a dextral gonopodium will orient differently than those with a sinistral gonopodium, consistent with the idea that there is link between behavioral lateralization and morphological handedness. If true, it would suggest that reproductive morphology could be linked to brain and behavioral lateralization in vertebrates.

Backman, Natalia; Ogden, Heath (Utah Valley University)
Faculty Advisor: Ogden, Heath (Utah Valley University, Biology)

Siphlonuridae is a family of mayflies (order Ephemeroptera) that are nicknamed the "Primitive" Minnow Mayfly family. The family traditionally has consisted of four genera; Edmundsius, Parameletus, Siphlonisca, and Siphlonurus, representing twenty six described species. The family Dipteromimidae was described as a sister group to the family Siphlonuridae (Tojo & Matsukawa, 2003), however, past molecular evidence suggests that Dipteromimidae might nest within Siphlonuridae(T. H. Ogden et al., 2009; T. Heath Ogden & Whiting, 2005). This study aims to use more taxa and more molecular data in order to generate more robust phylogeny for these mayflies. Specifically our goals are to (i) test the monophyly of the family Siphlonuridae; and (ii) compare traditional Sanger sequencing loci to newly generated phylogenomic data from a targeted capture sequencing approach.

Thatcher, Spencer; Eyere, Gloria (Dixie State University)
Faculty Advisor: O'Brien, Erin (College of Science, Engineering, and Sciences; Biological Sciences Department)

Dwarf bear-claw poppies (Arctomecon humilis Coville) are an endemic species of wildflower in Washington county Utah. These poppies only flower for about a month during the summer. There are currently seven known locations where these poppies are found. Conservation efforts to protect these populations includes research to understand the reproductive success of each site. Populations with low reproductive success may indicate the need for additional efforts or interventions to save this unique species. Four specific locations were monitored over a three-year period. Poppies in these areas were tagged and studied during their flowering seasons and individual inflorescences were bagged and collected to determine struggling locations and their correlating issues related to population decline. Seeds were split into two groups: immature and mature and were weighed and counted. A large percentage of immature seeds may indicate a resource or pollinator issue for the population. A low overall seed production may indicate that a resource limitation or other stressor is reducing the population viability.