All Wrapped Up: How Choice of Egg Wrapping Substrate During Oviposition Site Selection Affects Predation and Embryonic Growth in Eastern Newts

Parental care behaviors have a significant impact on the survivorship of offspring and therefore the inclusive fitness of the parent. These behaviors are broad and varied and include defending against predators, acquiring food, and choosing where to lay their eggs. The latter, oviposition site selection, has significant impact on embryo survivorship in oviparous animals, as the chosen sight can impact factors such as incubation temperature, predation risk, and resource availability. For amphibians, oviposition site selection is particularly crucial as their eggs lack a calcareous shell, leaving them more susceptible to environmental conditions and predation. In response to this, amphibians have evolved diverse and adaptive oviposition site selection behaviors to keep their aquatic embryos and larvae protected and hydrated. Though most oviparous amphibians lay their eggs in large masses, many newt species in the family Salamandridae lay individual eggs that they then wrap in materials found in the water. This unique behavior likely has a higher parental cost compared to laying in masses, but may offer some benefits, such as predator defense. With this oviposition site selection behavior comes a distinct choice: female newts wrap their eggs in either live aquatic vegetation or dead leaf litter, and each material chosen may confer unique benefits to the embryos. While some benefits of egg-wrapping have been studied, the effects of different wrapping materials on embryo development and predation rates remain undocumented. The goal of this thesis is to investigate the benefits and mechanisms of the unique egg-wrapping behavior by female newts. Eastern Newts (Notophthalmus viridescens) were chosen as a model species because they wrap their eggs in two 6 different materials: aquatic vegetation and dead leaves. Aquatic vegetation might supply additional oxygen to developing embryos while dead leaves may offer enhanced predator protection. We hypothesized that these two different wrapping materials would result in differing impacts on egg predation and embryonic development, and that predator presence would influence oviposition material choice in female newts. In the case of material choice, we hypothesized that females’ oviposition site selection would be influenced by the presence of egg predators, and that they would choose to lay eggs in either dead leaves or aquatic vegetation at differing rates depending on predator exposure. In the case of predation, we hypothesized that the predation rate would change depending on the material the eggs were wrapped in, if any. And in the case of development, we hypothesized that the two different egg wrapping materials used by newts would impact embryonic growth and development. To test these hypotheses, we ran three experiments in the springs of 2023 and 2024. The first laboratory experiment, outlined in Chapter 1, investigated whether the presence of an egg predator - Wood Frog (Lithobates sylvaticus) tadpoles - would affect females’ oviposition site choice of dead leaves or live aquatic vegetation. To do this, we utilized growth chambers and individual aquariums to provide controlled conditions that would allow the females to be exposed to visual and chemical cues from the tadpoles without the tadpoles able to access the eggs laid. We predicted that females housed with tadpoles (N = 10) would choose to wrap their eggs in dead leaves presumably because of enhanced predator protection by deal leaves, and females housed without tadpoles (N = 10) would choose to wrap their eggs in live aquatic vegetation presumably because of 7 additional oxygen provision to the embryo. I ran this experiment twice, and both times there were not enough eggs laid to test these predictions. Chapter 2 outlines a laboratory predation experiment to investigate whether different egg-wrapping materials affected predation rates using Wood Frog tadpoles and Eastern Newt eggs. I collected Eastern Newt eggs that were wrapped in either dead leaves or aquatic vegetation, a portion of which I then unwrapped. I then exposed groups of these eggs (N = 25 per treatment) to Wood Frog tadpoles for them to predate. We predicted that eggs wrapped in dead leaves would be eaten at the lowest rate, unwrapped eggs at the highest rate, and eggs wrapped in live aquatic vegetation between the two. Eggs wrapped in dead leaves were eaten significantly less than eggs with no wrapping, but there was no significant difference between eggs wrapped in live aquatic vegetation and eggs with no wrapping, and no significant difference between eggs wrapped in dead leaves and eggs wrapped in live aquatic vegetation. Finally, Chapter 3 outlines a laboratory experiment investigating whether the two different egg-wrapping materials - dead leaves or live aquatic vegetation - impact newt embryo development. We collected Eastern Newt eggs wrapped with the two different materials from mesocosms, in which gravid female newts were kept, and placed them in individual containers in growth chambers programmed to mimic outdoor conditions (N= 20 per treatment), then measured body size and larval period of the hatchlings. We predicted that eggs wrapped in live aquatic vegetation would hatch faster and larger than eggs wrapped in dead leaves. Embryos from eggs wrapped in live aquatic vegetation hatched on average three days earlier than those wrapped in dead leaves. However, the embryos from eggs 8 wrapped in live aquatic vegetation had shorter body length compared to those from eggs wrapped in dead leaves. Despite their smaller body sizes, the growth rate for eggs wrapped in live aquatic vegetation was significantly higher than that of eggs wrapped in dead leaves. The results from the studies outlined above suggest that the types of wrapping materials, dead leaves and live aquatic vegetation, have varying effects on larval development and predation rates. The results indicate that live aquatic vegetation confers developmental benefits to the embryos such as increased growth rate and shorter hatching time, while dead leaves are likely to provide improved protection from aquatic predators. We also found that larvae from live aquatic vegetation hatched smaller than larvae from eggs wrapped in dead leaves, and the predation rates between eggs wrapped in live aquatic vegetation and dead leaves were similar. These findings underscore the need for further research with increased sample sizes into the mechanisms underlying the unique oviposition site selection behaviors of Eastern Newts

WORLDS BUILT AND BORROWED: A PARACOSMIC EXPLORATION OF THE METATEXTUAL UNCONSCIOUS

This thesis explores literary phenomenology through the lens of fictional world-building and borrowing, integrating psychoanalytic play theories and reader response criticism, primarily through the works of D.W. Winnicott, Stanley Fish, and Wolfgang Iser. In applying this theoretical approach, the thesis investigates how fictional worlds function as intermediary phenomena through which creators can externalize and process their individual or collective experiences of being. Employing a comprehensive literary survey framework, the project spans a diverse range of texts, from canonical literature, such as the Brontës’ juvenilia and Orwell’s Nineteen Eighty-Four, to contemporary works like Stephenie Meyer’s Twilight and E.L. James’ Fifty Shades of Grey. By establishing literary worlds as externally preserved phenomenological expressions, the thesis reveals a transauthorial relationship between author, reader, and researcher, in which interpretation and recreative engagement facilitate narrative continuation. Through this process, a literary metatext, once unconscious, begins to emerge and gradually revives the functionality of fiction as a dynamic, imaginative play space where the full range of human experience can be explored and expressed

Medbh McGuckian

This wide-ranging study of one of the most innovative, daring, and important poetic voices in contemporary Ireland analyzes Mebdh McGuckian’s entire corpus, offering both an original contribution to the field of contemporary Irish literary studies and a readable synthesis of existing criticism that will be useful to academics and students. Thematically and methodologically unique, the book examines previously neglected subjects in McGuckian’s work, in particular the poet’s exploration of creativity and performativity, while also emphasizing the cohesiveness of individual volumes in light of the poet’s constant change and development. This critical investigation allows readers a deeper understanding of McGuckian’s topical preoccupations and the evolution of her distinctive poetic voice.https://digitalcommons.bucknell.edu/bucknell-press/1117/thumbnail.jp

Building Community at Work

Employees and managers alike seek ways to be happy and effective in the workplace--an arena in which we all spend many hours of our week. Community is an essential ingredient in a healthy and productive work environment: when asked what people like about their jobs, it\u27s not uncommon to hear We\u27re like a family, or Here, I\u27m part of a community. Considering the numerous models conceptualized to support creation of emotionally satisfying and behaviorally productive work settings, it is perhaps surprising that the topic of community at work has been underexplored.Based on sound theoretical foundations and empirical findings from the science of management and community research and action, Building Community at Work guides scholars, employees, and leaders of organizations toward creating communities at work in any institutional sector. To make abstract theory concrete, Neil Boyd weaves scientific models and concepts together with the story of a young business owner\u27s journey to becoming an industry leader in building communities. The book also provides practical considerations for professionals to analyze and conceive ways to create communities at work. In Boyd\u27s accessible and grounded analysis, find the building blocks for transforming the workplace into a flourishing community.https://digitalcommons.bucknell.edu/books/1314/thumbnail.jp

A Complete Inference System for Probabilistic Infinite Trace Equivalence

We present the first sound and complete axiomatization of infinite trace semantics for generative probabilistic transition systems. Our approach is categorical, and we build on recent results on proper functors over convex sets. At the core of our proof is a characterization of infinite traces as the final coalgebra of a functor over convex algebras. Somewhat surprisingly, our axiomatization of infinite trace semantics coincides with that of finite trace semantics, even though the techniques used in the completeness proof are significantly different

The Effect of Sequence on Structure and Microbial Properties of Insect Antimicrobial Peptides

Antibiotic resistance is a growing crisis worldwide, and antimicrobial peptides (AMPs) are emerging as a promising alternative to traditional antibiotics. AMPs, short chains of 10-60 amino acids, are produced by a wide variety of organisms, including insects. This work is focused on the cecropin family, a group of insect AMPs known for their α-helical structure and low toxicity to mammalian cells. Cecropin sequences were sourced from protein databases, with mature peptide forms isolated by removing signal sequences and duplicates. We examine how small variations in amino acid sequences, particularly in regions predicted to serve as hinges between two α-helices, impact both the biophysical properties and antimicrobial behavior of these peptides. The peptides were first categorized by biochemical properties, including hydrophobicity, amphiphilicity, and net charge, to predict their antimicrobial activity. Structural modeling for one category of peptides predicted three primary α-helical conformations, linear, bent, and hinged, suggesting that similarly sequenced peptides can have differing abilities to form multiple conformations and potential membrane insertion mechanisms or capabilities. However, differences in amino acid properties at positions 22 and 23 were suggestive of their predicted structure. Selected peptides were synthesized and their structure was analyzed, which confirmed that they adopt α-helical structures in membrane-mimetic environments, though observed differences in α-helicity between peptides were not correlated with predicted structures. Then, the antimicrobial activity of each peptide was determined against bacterial species including Escherichia coli, Pseudomonas aeruginosa, and two strains of Providencia burhodogranariea. Differences in antibacterial activity were observed, revealing that even small sequence and structural differences can significantly impact peptide efficacy. While increased predicted linearity generally corresponded with greater activity, supporting expectations based on hinge flexibility, this trend was not consistent across all bacterial species. This work aims to improve the rational design of AMPs with improved specificity and potency, addressing the urgent need for new antimicrobial agents in the face of rising antibiotic resistance