Mealworms (Tenebrio molitor), the larval stage of yellow mealworm beetles, are a popular feeder insect for birds, amphibians, reptiles, fish, and even human populations throughout the world. As such, the goal of this work was to understand how the diet of mealworms impacts their nutritional quality as variations in quality can impact the animals (and humans) that consume them. In this study, 500 mealworms were divided among each of the following substrates designed to model food sources available in urban versus rural, more natural areas: 100% wheat germ (control); 100% Styrofoam; mixture of soil, grasses, and leaves from urban lawns; a mixture of soil, grasses and leaves from rural lawns; 50% mixture of wheat germ + carrots; natural fertilizer; or fertilizer with weed killer. The mealworms were maintained at room temperature and the diets were replaced bi-weekly to prevent spoilage and to remove mealworm waste. Once a week for three weeks, mealworms were sampled from each substrate and frozen at -20°C. After 3 weeks, mealworms housed in wheat germ + carrots weighed significantly more than all other groups (p<0.05), whereas those housed in Styrofoam or urban lawn substrates weighed significantly less at week 3 as compared to week 1 (p<0.01). The urban lawn substrate resulted in greater molting and contained the highest number of pupae, but also the greatest mortality among the substrates. The Bradford method measured the total protein content of mealworms homogenized in phosphate-buffered saline. Mealworms maintained on wheat germ had significantly greater total protein content as compared to mealworms transitioned to any other diet (p<0.05). So, compared to wheat germ, urban foods generally reduced protein, total sugars, and crude fat, although they also decreased oxidized lipoproteins. Urban lawn had lower oxidized lipoprotein content than wheat germ, but levels were higher compared to wheat germ with carrots and natural fertilizer. In addition, urban foods generally increase the water content in mealworms. Urban foods were not much different from rural lawns as no there was difference between urban and rural lawns. Differences in body mass and total protein support the hypothesis that mealworms' nutritional quality is altered by ingesting urban substrates. These data suggest that mealworms (and potentially other insects) in cities may be exposed to food substrates that result in less nutritional value than those living in more natural areas as mimicked by the rural lawn substrates and wheat germ control, although they may be higher in water content.

Serotonin 1B receptors (5-HT1BRs) are involved in cocaine reward via regulating activity of dopamine neurons. The 5-HT1BR agonist CP-94,253 or 5-HT1BR overexpression in the nucleus accumbens shell (NAcSh) enhances cocaine intake during maintenance of daily self-administration (SA) but inhibits intake after 21 days of abstinence in male rats. My central hypothesis is that CP-94,253 acts at 5-HT1BRs located on the terminals of NAcSh GABA neurons that undergo regulatory changes in response to cocaine SA and subsequent abstinence resulting in an abstinence-induced switch in the functional effects of CP-94,253 in both male and female rats. In the first series of experiments, I compared the functional effects of CP-94,253 in female rats to male rats: 1) during maintenance of daily cocaine SA, 2) after 21-60 days abstinence, and 3) during the resumption of cocaine SA after abstinence (i.e. model of relapse). I found that CP-94,253 enhanced cocaine intake and breakpoints on a high-effort progressive ratio schedule of cocaine reinforcement during maintenance regardless of sex. By contrast, CP-94,253 attenuated cocaine intake after 21 days of abstinence and during the relapse test, regardless of sex. These findings suggest: 1) an abstinence-induced inhibitory effect of the 5-HT1BR agonist occurs in both sexes, 2) these inhibitory effects are long-lasting, and 3) the agonist may provide a novel therapeutic for cocaine use disorders. I next used RNAscope in situ hybridization to measure regulatory changes in 5-HT1BR mRNA expression and its co-expression with GABAergic and glutamatergic cell markers in the lateral and medial NAcSh subregions after abstinence from cocaine. I found no significant changes in these measures in either subregion of NAcSh after prolonged abstinence in either sex; however, I did observe that 95% of 5-HT1BR mRNA is co-localized in GABAergic neurons, whereas <2% is co-localized in glutamatergic cells. Future research investigating abstinence-induced, functional changes in 5-HT1BRs in subregions of the NAcSh is an alternate approach to further test my hypothesis. This research is important for the development of 5-HT1BR agonists as putative treatments of cocaine use disorders.

Coral reefs provide essential social, economic, and ecological services for millions of people worldwide. Yet, climate change and local anthropogenic stressors are damaging reefs globally, compromising reef-building capacity, and therefore impacting functionality. Growth of coral reefs depends upon the production and maintenance of the reef framework when calcium carbonate production exceeds erosion, and utilization of remote sensing to scale-up estimates of reef carbonate production remains limited. This study provided a first field estimate of net carbonate production on Hawaiʻi Island, in Hōnaunau Bay, and used high-resolution benthic-cover data, derived from Global Airborne Observatory (GAO) airborne imaging spectroscopy, to scale-up estimates. Net carbonate production was, on average, 0.5 kg CaCO3 m-2 y-1 across the depth gradient, with the highest rates of approximately 2.4 kg CaCO3 m-2 y-1 at 6 m. Urchins, especially the abundant Echinometra, suppressed reef-accretion potential in the shallow reef (< 6 m) and urchin bioerosion decreased with depth. Critically, a threshold of ~26% live-coral cover is currently needed to maintain positive net production across depths. Scaling-up estimates were achieved using a 2 m resolution map of live-coral cover collected by the GAO. Overall, field measurements translate to average vertical reef growth of 0.5 mm y-1 across depths, whereas sea level is currently increasing at 3.55 mm y-1, suggesting the reef in its present status is not keeping pace with sea-level rise. This work lays the foundation to enhance monitoring of carbonate production over increased temporal and spatial scales with airborne imaging spectroscopy — to help determine where reefs are potentially keeping up with anthropogenic stressors, ocean warming, and sea-level rise — and to help inform restoration and management decisions that support resilient carbonate budgets of coral reefs.

As water is essential for survival, seasonal scarcity of freshwater resources can pose a challenge for many species. In xeric environments, efficient location of ephemeral water is crucial to capitalize on this rare, critical resource. Yet little is known about how organisms locate water, though it has been acknowledged that olfactory spatial navigation may benefit water searching in xeric-adapted species. Additionally, drinking behavior may be influenced by water salinity as consuming water with salinity levels that exceed blood osmolality can induce or exacerbate dehydration. To investigate whether animals can locate water via olfaction, whether salinity affects the amount of water consumed, and whether the extent of dehydration affects both processes, I conducted three experiments in a xeric-adapted reptile, the Gila monster (Heloderma suspectum). Two experiments used a T-maze to examine the effects of various olfactory cues and hydration state on spatial navigation to water resources, while the third experiment examined willingness to drink water of various salinity levels depending on the extent of dehydration. I found that Gila monsters accurately navigated to olfactory cues associated with aged tap water, but not other olfactory cues (pond water, geosmin/MIB, IBMP/IPMP). Increased extent of dehydration correlated with greater spatial navigation efficiency but did not meaningfully impact navigation accuracy. Moderately dehydrated Gila monsters selectively consumed water with lower salinity levels (freshwater, 1,250 ppm, and 2,500 ppm) and avoided highly saline water resources (10,000 ppm and 20,000 ppm). However, considerably dehydrated animals demonstrated an increased propensity to consume water with higher salinity levels. These results provide evidence for olfactory spatial navigation and selective consumption of saline water as strategies to locate water and efficiently osmoregulate in an osmotically challenging environment. These findings underscore the observed adaptable physiological and behavioral traits Gila monsters and other xeric-adapted species use to endure the seasonal water limitations.

To combat the global antimalarial resistance crisis effective resistance management strategies are needed. To do so, I need to gain a better understanding of the ecological interactions occurring within malaria infections. Despite the importance of the complex interplay among co-infecting strains, our current knowledge and empirical data of within-host diversity and malaria disease dynamics is limited. In this thesis, I explore the multifaceted dynamics of malaria infections through an ecological lens. My overall research question is: "How do ecological interactions, including niche complementarity, competition dynamics, and the cost of resistance, shape the outcomes of malaria infections, and what implications does this have on understanding and improving resistance management strategies?” In Chapter II, titled “Niche Complementarity in Malaria Infections” I demonstrate that ecological principles are observed in malarial infections by experimentally manipulating the biodiversity of rodent malaria P. chabaudi infections. I observed that some parasites experienced competitive suppression, others experienced competitive facilitation, while others were not impacted. Next, in Chapter III, titled “Determining the Differential Impact of Competition Between Genetically Distinct Plasmodium falciparum Strains” I investigate the differential effect of competition among six genetically distinct strains. The impact of competition varied between strain combinations, and both suppression and facilitation were observed, but most pairings had no competitive interactions. Lastly, in Chapter IV, titled “Assessing Fitness Costs in Malaria Parasites: A Comprehensive Review and Implications for Drug Resistance Management”, I summarize where the field currently stands and what evidence there is for the presence of a fitness cost, or lack thereof, and I highlight the current gaps in knowledge. I found that evidence from field, in vitro, and animal models are overall suggestive of the presence of a fitness cost, however, these costs were not always found. Amid the current focus on malaria eradication, it is crucial to understand the impact of biodiversity on disease severity. By incorporating an ecological approach to infectious disease systems, I can gain insights on within-host interactions and how they impact parasite fitness and transmissibility.

Territoriality is seen across different species of animals anywhere, from birds, fish, and mammals to reptiles. Although many animals use several types of signals to defend their territories, signals in different sensory modalities have varying properties that may influence their effectiveness in different contexts. This study investigates whether male plateau fence lizards (Sceloporus tristichus) use chemical or visual behavior during territory defense. Both visual and chemical communication modalities inform the audience about the producer’s physiological condition. The results show no obvious tradeoff between visual and chemical modalities in the behavior recorded in the presence of another male lizard compared to when undisturbed, suggesting that these signals are not used in territory defense. An increased visual head bob display is the most common spiny lizard territory defense response to conspecific intruders. However, this is not always the case, as environmental and evolutionary constraints influence communication. This species does not perform typical territorial behavior. However, there was a significant increase in aggressive visual displays, called full shows, in the presence of the intruding live stimulus. An increase in full shows could be a less conspicuous way to defend their territory instead of performing an entire broadcasting head bob display while perched in an open/exposed habitat notably filled with predatory birds. This shows modification within one communication modality to result in more effective communication.

The genus Buellia remains one of the largest, poorly resolved genera of crustose lichens world-wide. A global revision is challenging because of its enormous diversity .As a step towards a more comprehensive revision, three easily separated groups were examined. Buellia sulphurica is easily recognized by its vivid yellow color, caused by rhizocarpic acid, a secondary metabolite rarely reported from the genus. The species has been considered endemic to the Galapagos, but it is morphologically and anatomically almost identical to B. xanthinula, a taxon previously described from Brazil. Moreover, both have rhizocarpic acid. Additionally, a specimen from Georgia with a similar morphology and anatomy with identical secondary chemistry has been examined here. Based on this research, it is discussed whether all three taxa represent a single species. Another aspect of the research presented here focused on species of Buellia that parasitize other lichens. It is generally assumed that they are strongly host-specific. Parasitic specimens of Buellia recently collected in the Great Basin are morphologically similar to taxa previously reported from Northern Europe, South America, and North America. Preliminary studies, comparing the material with specimens of B. uberior, B. miriquidica, B. malmei and B. imshaugii, suggest that the Great Basin material is best recognized as representatives of distinct, currently undescribed species. Finally, as part of this thesis a group of specimens from the Galapagos containing xanthones has been examined. This heterogeneous group represents an assemblage of taxa that are not necessarily closely related, but easily recognized by their bright yellow to orange UV-fluorescence and orange spot test reaction with sodium hypochlorite. For this group, morphological and anatomical characters were documented, and their secondary chemistry analyzed with thin-layer chromatography. For all three groups, i.e., the Buellia xanthinula-group, the parasitic species, and the ones with xanthones, detailed descriptions are provided.

There is increasing interest in growing strawberries (Fragaria ×ananassa) in indoor environments such as vertical farms, as the continued sustainability of outdoor production is threatened due to reductions in arable land, labor shortages, and an increased frequency of drought. However, the optimal conditions for growing strawberries hydroponically in sole-source lighting conditions have yet to be established. The objectives of this research were to investigate the optimal lighting conditions and nutrient concentrations for strawberry production in vertical farming. In the first study, bare-root plants of two strawberry cultivars, ‘Albion’ and ‘Monterey’, were grown in an indoor vertical farm under a 22 °C air temperature and an 18-h photoperiod with 90 μmol·m−2·s−1 of blue light and 250 μmol·m−2·s−1 of red light with and without 50 μmol·m−2·s−1 of additional far-red light from light-emitting diodes. Adding far-red light increased the fruit number per plant by 36%, total fruit fresh mass by 48%, and total soluble solids content by 12% in ‘Albion’, but not ‘Monterey’. In the second study, bare root plants of strawberries ‘Monterey’ and ‘San Andreas’ were grown under a 23 °C air temperature and an 18-h photoperiod with an extended photosynthetic photon flux density of 350 μmol·m−2·s−1. Plants were subjected to four potassium to nitrogen ratios (K:N) of 1.5:1, 2.5:1, 3.5:1, and 4.5:1 in a deep-water culture hydroponic system. Increasing K:N from 1.5:1 to 4.5:1 increased the root dry mass of ‘Monterey’, but generally had little to no effect on vegetative growth in either cultivar. In addition, in both cultivars, increasing K:N from 1.5:1 to 4.5:1 decreased individual fruit size and increased titratable acidity. These results suggest that for indoor strawberry production, including far-red light in sole-source lighting can improve fruit production in some strawberry cultivars. However, increasing K:N in the hydroponic nutrient solution generally does not benefit plant growth, fruit production, and fruit quality.

Reactive oxygen species (ROS) including superoxide, hydrogen peroxide, and hydroxyl radicals occur naturally as a byproduct of aerobic respiration. To mitigate damages caused by ROS, Escherichia coli employs defenses including two cytosolic superoxide dismutases (SODs), which convert superoxide to hydrogen peroxide. Deletion of both sodA and sodB, the genes coding for the cytosolic SOD enzymes, results in a strain that is unable to grow on minimal medium without amino acid supplementation. Additionally, deletion of both cytosolic SOD enzymes in a background containing the relA1 allele, an inactive version of the relA gene that contributes to activation of stringent response by amino acid starvation, results in a strain that is unable to grow aerobically, even on rich medium. These observations point to a relationship between the stringent response and oxidative stress. To gain insight into this relationship, suppressors were isolated by growing the ∆sodAB relA1 cells aerobically on rich medium, and seven suppressors were further examined to characterize distinct colony sizes and temperature sensitivity phenotypes. In three of these suppressor-containing strains, the relA1 allele was successfully replaced by the wild type relA allele to allow further study in aerobic conditions. None of those three suppressors were found to increase tolerance to exogenous superoxides produced by paraquat, which shows that these mutations only overcome the superoxide buildup that naturally occurs from deletion of SODs. Because each of these suppressors had unique phenotypes, it is likely that they confer tolerance to SOD-dependent superoxide buildup by different mechanisms. Two of these three suppressors have been sent for whole-genome sequencing to identify the location of the suppressor mutation and determine the mechanism by which they confer superoxide tolerance.