Ecology and Management of the Asiatic Garden Beetle, Maladera formosae, in Corn-Soybean Rotated Agroecosystems

Pekarcik, Adrian Joseph The Ohio State University ProQuest Dissertations & 2022 해외박사(DDOD)

The Asiatic garden beetle, Maladera formosae (Brenske) (syn. M. castanea [Arrow]), is an annual white grub species that was introduced to North America 100 years ago and quickly established as a pest of turf-grass, ornamentals, and vegetables in the Mid-Atlantic states. Over time, economic damage to these crops by M. formosae became merely sporadic, though its geographic range continued to expand. Now, in 2022, it is reported in at least 25 states and two Canadian provinces. Unexpectedly, in the last 15 years M. formosae emerged as a significant, early-season pest of field corn grown in sandy soils of the Great Lakes region. The beetle overwinters in the soil as a grub and in the spring second and third instars feed on seedling corn roots shortly after planting, causing stand loss that can exceed 40%. Management is difficult and many chemical products used against other annual white grub species are ineffective against M. formosae.Many questions surround the recent emergence of this near-endemic species as a corn pest nearly 100 years after its introduction, and we are hampered in its study by a lack of research techniques designed for use in field crops, and by a lack of understanding of its basic life history in the climate and habitats of this region of the country. The overall goal of this research was to investigate the ecology and management of M. formosae in corn-soybean rotated agricultural systems of the Great Lakes region.At the time M. formosae emerged as a pest in the Great Lakes region, most available literature stemmed from horticultural settings of New York and New Jersey in the 1930s. Scouting for M. formosae grubs is problematic as the grubs are subterranean and adults are nocturnal, and no standardized sampling methods have been developed for the species. To develop sampling methods for grubs in corn-soybean rotated fields, I first evaluated the compact cutter, cup cutter, and wire-mesh bait station. The cup cutter, which takes a smaller but deeper soil sample than the compact cutter, sampled more grubs per soil volume and was more sensitive to smaller grub populations. The bait station, a passive sampling technique, and cup cutter were both successful at detecting M. formosae before planting. However, the cup cutter is more efficient and economical since it can be used with less equipment in a single trip to the field. I then investigated sampling methods for the adults, since they are responsible for laying eggs that hatch into the grubs that overwinter and feed on corn roots the following spring. I performed two experiments: one to evaluate pitfall traps and sticky cards for sampling beetle emergence, and the other to evaluate milkjug traps and blacklight traps for sampling beetle flight. Pitfall traps were effective at capturing beetles, but not sticky cards. Peak abundance was observed between June 28 and July 5. Flying adults were strongly attracted to the blacklight trap, which caught nearly100-times more adults than the milkjug traps. These sampling tools are useful for researching the life history characteristics of M. formosae in field cropping systems.I then evaluated the life history characteristics of M. formosae in Michigan and Ohio corn-soybean rotated fields in 2018 and 2019. In Michigan and Ohio, about 40-50% and 25-30% of grubs emerging from overwintered grubs are second instar, respectively. Second instars were sampled as late as mid-June in Ohio and early July in Michigan. In both states most grubs emerged from overwintering in the third (and final) instar. Grub activity was detected in mid-April, peaked in May, and declined through June. Grubs were no longer sampled in Ohio by mid-June, but remained in the soil until July 1 in Michigan. Pupae in Michigan were first recovered one to two weeks later than in Ohio. Of the diet options typically available in a corn-soybean rotated field, grubs generally showed preference for ? and gained significant body mass when subjected to corn and marestail (a weed) but were also able to survive and develop on soybean, crop residues and bare soil. Grubs are also concentrated to soils with sand content exceeding 75%; relatively few grubs, if any, are sampled in loamy soils. In particular, grub distribution was most affected by sand and clay content, and soil moisture.I monitored adult ground movement and flight using pitfall traps and milk jug traps, respectively. Adult emergence out of the ground in Michigan occurred one to two weeks later than in Ohio. Adult movement around the soil surface peaked during the last week of June in Ohio and the first week of July in Michigan. In both states, ground movement significantly declined shortly after peak flight activity and never recovered. Adult capture rates also increased in soils with sand content exceeding 75%. Adult flight, which requires warm night temperatures around 20°C, peaked at the same time in early July in both states. Unlike ground movement, adult flight steadily declined throughout July into August. Beetle flight did not seem to be influenced by adjacent or surrounding habitat type. However, there were significantly more flying males than females during peak flight. The sex of beetles was determined from the orientation of the posterior abdominal sternite and pygidium, a newly reported sex-determination feature for M. formosae. Understanding the timing and duration of M. formosae life stages in corn-soybean rotated fields of the Great Lakes region will ultimately inform the timing and implementation of management strategies.Management of this pest is difficult in affected fields. Soil-applied and seed-applied insecticides are often used for management of soil-dwelling insects. However, M. formosae has been observed at high densities in fields planted with neonicotinoid-treated seed treatments and in-furrow pesticides. Entomopathogenic nematodes are a biological control agent used to manage M. formosae grubs in turfgrass. I examined their potential to control M. formosae in field corn. I isolated three species of naturally occurring entomopathogenic nematode, Heterorhabditis bacteriophora, H. megidis, and Steinernema glaseri, from infested fields in northern Ohio, and I confirmed their ability to infect and kill M. formosae grubs in greenhouse and microplot field trials. Relative to commercially available nematode isolates, locally isolated species are already preadapted to local environmental extremes and persist and suppress pest populations longer.Perhaps the most mysterious question surrounding the recent advent of M. formosae as a corn pest in the Great Lakes region is why, why corn, why here, why now? A first step in addressing these questions is to diagnose the population structure of M. formosae in this region relative to other regions. I conducted the first population genetics study on M. formosae populations sampled from three regions in the U.S.: Mid-Atlantic, New England, and the Great Lakes regions. Low genetic variation was detected among populations from different regions or habitats. However, only three genes were used to assess population structure. A genome-based approach with more intensive sampling is needed to gain higher resolution and determine if populations in the corn-pest region are genetically clustered. This knowledge could help predict the likelihood that M. formosae could become a significant pest of field corn in other areas.

Rivals for Governance of the Land-Grant University: Farmers, Alumni, and Administration at the Ohio State University, 1870-1910

Harraman, Joshua Michael The Ohio State University ProQuest Dissertations & 2019 해외박사(DDOD)

Many believe that farmers were originally supportive of the land-grant colleges because of the focus on agricultural science as part of the land-grant curriculum. Although land-grant colleges and farmers are generally aligned in their interests and efforts today, the farmers of the 1850s-early 1900s actually challenged the land-grant colleges for control of governance and funding. Often these challenges occurred between farmers and colleges in Congress and state legislatures. Meanwhile, the alumni were a disorganized group prior to the 1910s that often challenged the university administration's authority and control of the college. Yet, in order to compete with the farmers, the land-grant colleges needed to identify a group of advocates who would lobby legislatures on the land-grant colleges behalf. My research focuses on how one institution, the Ohio State University, used its alumni to parry the attacks of farmers in the early 1910s. Research has been limited on the relationship between the land-grant universities' administration, farmers, and the alumni. Even more limited is the literature that exists about alumni relations during the formative years of the profession (1890-1920). My research identifies how the Ohio State University established authority over the disparate alumni groups in order to use the alumni as advocates in Congress and the state legislature to combat the farmers.

Quantum Chemical Studies of Charge-Separated States and X-Ray Absorption Spectroscopy with Time Dependent Kohn-Sham Theory

Alam, Bushra The Ohio State University ProQuest Dissertations & 2021 해외박사(DDOD)

In the following studies, we explore several different categories of excited states encountered in chemistry in the solid, liquid and gaseous phase. These investigations are either aimed at understanding the disputed behaviour of certain excited states, or the development of methodology that can provide a more complete description of them. First, we have looked at the extent of charge separation in the low lying excited states in pentacene which is an organic photovoltaic material that can generate multiple charge carriers from a single excitation. Theoretical studies have reached differing conclusions regarding the role of charge separation in this material and to to investigate this, we have used a fragment based model to examine size-dependent trends, in models ranging from a dimer to hexamer. We have done this to understand the change in the energetics from the gas phase to the bulk. We have also conducted calculations using theoretical tools which have been optimized to give an accurate description of the underlying electronic structure of these systems. Our results suggest that the low lying excited states of this material are indeed charge separated, and this is more pronounced as the system size increases. Hence , studies based on small models or methodology unsuited for these systems, can miss out on the bulk interactions present in a crystal environment, and reach erroneous conclusions about charge separation in these states. This resolves a long standing debate between high level quantum chemistry studies on small clusters and periodic calculations which simulate the bulk crystal. Another theoretical methodology used to study charge separated states and multiexciton states (characterized by excitations in multiple centres) in systems like pentacene, is provided by the restricted active space spin-flip (RAS-SF) family of methods. However, in it's current framework, these can only be conducted in the vacuum phase. However, charge separated states are known to interact strongly with a solvent, which can differentially stabilize the different species involved in such reactions, and hence impact the reaction mechanism. We have thus adapted this method to include the effects of non-equilibrium solvation, which is an accurate method of including solvent polarization to excited states , when the change in the charge density of a system is substantial (such as in charge separated states). We have benchmarked this against systems known for their charge separated excited states, and demonstrated the asymptotic trends that the excitation energies are expected to follow with increasing distance of charge separation. Another category of excited states that we have studied are excitations originating from core electrons.The calculation of these via more conventional techniques is prohibitive due to the high cost and memory requirements, and we have demonstrated the utility of using the time dependent Kohn Sham (TDKS) approach developed in our group for the calculation of these. This TDKS implementation , which includes the use of complex absorbing potentials (CAPs) and Pade accelerated transforms offer significant advantages over an implementation that does not use these, as it significantly reduces the total time required to obtain a converged spectra. We further demonstrate this cost-effective TDKS approach by application to a copper dithiolene complex, wherebinding of a ligand is detectable via shifts in the sulfur K-edge.

Unfinished, Unloved, Unkra: The Formation, Life, and Financial Enervation of the United Nations Korean Reconstruction Agency (1950-1954)

McMahon, Ryan Patrick Francis The Ohio State University ProQuest Dissertations & 2017 해외박사(DDOD)

My project examines the formation, activation, and first forty-six months of life of the United Nations Korean Reconstruction Agency (UNKRA/the Agency), designed to render civilian-sector aid to South Korea during and after the Korean War. The offspring of American priorities, interests, and majority funding, UNKRA was inextricably implicated in the Cold War. Although initially conceived as a possible template for future United Nations aid to other countries, the late 1950 retreat of anti-Communist forces in the Korean War stunted the Agency's potential, and created for it a most difficult organizational life.Employing a combination of archives left by UNKRA and its top three major backer states (the United States, United Kingdom, and Canada), as well as the papers of persons with a connection to the Agency, I seize upon two themes to argue that UNKRA was less thoroughly co-opted by the United States than suggested by the Agency's context, and by the background of its two sequential leaders: Agents General J. Donald Kingsley (former Truman Administration employee and head of the International Refugee Organization [IRO]), and John B. Coulter (former U.S. Army Lieutenant-General). Specifically, and in part building on threads within existing scholarship, I argue that 1) the willfulness of UNKRA's leaders, and 2) their respective positive attitudes towards the U.N. system, contributed to the Agency's limited but notable resistance against United States direction — at least below the level of major policy.By the standards of more structurally independent parts of the United Nations system, UNKRA's resistance to United States suggestion was not impressive. However, the context of UNKRA's incredibly United States-centric existence creates a different standard for judging the Agency. That UNKRA's first leader (Kingsley) sought to transform the Agency into something grand, expansive, and probably permanent may not have been appropriate to UNKRA's stunted situation, but it echoed the apparent original, U.N.-reifying concept of the Agency as a template. Though the United States no longer wanted such a grand program, that did not stop UNKRA — drawing on its IRO heritage — from trying to 'evolve' into a new U.N. specialized agency. The second leader (Coulter) evinced greater interest in South Korea than organizational apotheosis — he also enjoyed wider operational opportunities than his predecessor. But Coulter, like Kingsley, also possessed an apparently genuine faith in the importance of the U.N. — particularly in the context of American interests.Where Kingsley bitterly fought the State Department on all manner of issues, Coulter took a more restrained approach. Even so, Coulter's equation of U.S. and U.N. interests allowed him to rationalize an occasionally bitter — and State Department-challenging — rearguard action to preserve a penurious UNKRA, and thus serve what he saw as the mutually compatible interests of South Korea, the United States, and the United Nations. Nevertheless, Coulter could not save the Agency's financial future after 1954. UNKRA hobbled to a close in phases, shutting down completely in 1960: unfinished in work, and unloved by history.

Booster Seat Use and Child Passenger Safety in Ohio, United States

Li, Li The Ohio State University ProQuest Dissertations & 2021 해외박사(DDOD)

Motor vehicle crash (MVC) related injuries remain the leading cause of death among children in the US. Age and size appropriate child restraint systems reduce the risk of MVC-related injuries. The American Academy of Pediatrics recommends that children who outgrow harness-based car seats should continue to use booster seats until they reach 57 inches tall. Many countries and US states have enacted legislation to promote the use of child restraint systems. However, the premature transition from using booster seats to seat belts is a public health hazard to children. The overarching goal of this dissertation was to examine the motor vehicle safety of child passengers by investigating the premature transition from booster seats to seat belts. The findings could be used to promote the appropriate use of child restraint systems and improve child passenger safety.The first aim of this dissertation (Chapter 3) was to compare the effectiveness of booster seats versus seat belts in protecting children aged 4 to 8 involved in MVCs. This chapter utilized data from Ohio Crash Outcome Data Evaluation System (CODES) from 2013 to 2016. By using propensity score methods with robust Poisson regression analysis, we found that children with booster seats had an 11% lower risk for overall MVC-related injuries, an 18% lower risk for moderate to severe injury, and a 59% lower risk for sustaining abdominal injury compared to those with seat belts alone.The second aim (Chapter 4) was to evaluate the impact of Ohio's booster seat law on child restraint use and MVC-related injuries. We included 18 years (2000-2017) of Ohio police accident report data and utilized an interrupted time series analysis with the generalized least-squares method. Our results indicated that Ohio's booster seat law was associated with an 18% increase in the proportion of age appropriate restraint use among children aged 4-7 years involved in MVCs, with this increase in usage occurring immediately after implementing the Ohio booster seat law and sustaining over several years. We also observed a negative association between the law and MVC-related injuries, though the statistical association was not reached at the significance level of 0.05.The third aim (Chapter 5) was to explore factors that influence parents' decision-making on their children's transition from booster seats to seat belts. We conducted 20 semi-structured interviews virtually with parents whose first child made the transition within the last year. We audio-recorded and transcribed all the interviews. This study identified three child-related themes and five parent-related themes associated with parents' decision-making on transitioning from booster seats to seat belts. We also found that the internet was the most common information source when parents sought child passenger safety knowledge. The majority of participants were aware of the Ohio booster seat law and used the law as a guideline, but misunderstanding and misinterpretation existed regarding age and height requirements.This dissertation demonstrates that using booster seats could reduce injuries among children aged 4-8 involved in MVCs. Children who prematurely transition to seat belts have a higher risk of MVC-related injuries. Ohio's statewide booster seat law was effective in promoting the age appropriate restraint use of children at booster seat age, even though the law was secondary enforcement. This dissertation also highlighted the importance of redesigning educational materials to improve parents/caregivers' knowledge and practice regarding correctly transitioning their children from booster seats to seat belts.

Landscape Genetics, Demographic Models and Conservation of the Eastern Massasauga Rattlesnake (Sistrurus catenatus)

Martin, Scott Anthony The Ohio State University ProQuest Dissertations & 2022 해외박사(DDOD)

Successful conservation actions require a detailed understanding of how individuals interact with their environment. For many threatened and endangered species, anthropogenic changes to their landscape have created barriers separating formerly connected populations. This isolation can have profound impacts on the long-term viability of these populations and ultimately the conservation status of the species. For example, as populations become more isolated, they may enter the 'extinction vortex' where small populations experience high levels of inbreeding and genetic drift depressing demographic rates, driving the population into a positive feedback loop that can lead to a decline in numbers and eventual extinction. However, if barriers to movement are not complete, even infrequent dispersal between populations can counter potential vortex effects by bolstering local population sizes and introducing new genetic material.Determining if populations are connected via dispersal or if they are isolated is a difficult question with no single best approach. For the Federally threatened Eastern Massasauga Rattlesnakes, Sistrurus catenatus, their reclusive, sedentary lifestyle make many field-based methods for generating this information difficult and unreliable without unrealistic investments of time and resources. In my thesis, I used information from DNA single nucleotide polymorphisms (SNPs) from neutral genetic markers to address the following three fundamental questions regarding how S. catenatus move through their landscape in Ohio and how this information can be used to evaluate proposed activities for their conservation: (1) Do snakes in scattered habitat patches across Northeastern Ohio belong to a single connected population, a metapopulation with infrequent dispersal, or isolated populations? I used 1000s of DNA SNPs to reconstruct a pedigree across 86 individuals and showed that no individuals have moved between habitat patches separated by more than a few meters in the last three generations. This is despite known movements of over 2 km by individual snakes in other populations of this species found in more continuous habitat. From these results, I concluded that S. catenatus in NE Ohio is split into five genetically distinct populations in an area smaller than 15 km2 with no recent connectivity. (2) What landscape features drive the observed lack of connectivity? I next used the same SNP dataset with a second SNP dataset collected from 103 S. catenatus from a large population in Central Ohio to model landcover features that potentially impact resistance to movement between local habitat patches. I found that an inherent landscape feature, elevation, and contemporary landcover, specifically roads, were the main barriers to connectivity. I then used the resistance maps and pedigrees for S. catenatus populations in NE Ohio and Central Ohio to estimate the resistance values between all pairs of closely related individuals and used those to estimate dispersal kernels around each population. The kernels results reinforced our previous finding of no contemporary connectivity between S. catenatus populations in this region. (3) How would proposed management actions impact the demographic viability of S. catenatus in NE Ohio? The habitat occupied by populations of S. catenatus in NE Ohio has been targets of active management to prevent vegetation succession, and there has been increased interest in additional habitat management. Suggested management actions for individual S. catenatus populations have focused on increasing habitat sizes, increasing the frequency of woody vegetation removal, creating habitat between populations, and translocating snakes between populations. I built forward-in-time simulations of population trends under current management and five alternative management activities using resistance maps that I previously developed in Population Viability Analysis (PVA) models. I found that connectivity improvements via the formation of new habitats (and ideally new populations) between the current populations or a hybrid connectivity/translocation strategy offered the greatest improvement towards both overall population size and the number of occupied patches. These connectivity models were superior to the base scenario representing no changes to management.Overall, my research has generated novel tools and approaches based on landscape genetics and demographic modeling for conservation of endangered and threatened species in fragmented landscapes. When applied to S. catenatus population is in NE Ohio, these approaches have provided new and significant insights on contemporary population structure in S. catenatus in NE Ohio, how the landscape created the observed patterns, and how this information can be used to generate management recommendations to promote the long-term persistence of this threatened reptile.

Creating a `Civilized Nation?: Religion, Social Capital, and the Cultural Foundations of Early American State Formation

Boonshoft, Mark The Ohio State University ProQuest Dissertations & 2015 해외박사(DDOD)

From the very founding of the United States, education’s actual influence on American society has not measured up to Americans’ belief in education as a vehicle of meritocracy. Shortly after the American Revolution, the lexicographer, editor, and would-be education reformer, Noah Webster noted that in the United States “The constitutions are republican and the laws of education are monarchical.” For Webster, this paradox threatened to destroy the American republic. He and many others believed that education inculcated societal morals that were the foundation of republican government. Americans did not adopt any of Webster’s proposed solutions—namely a public school system—until the nineteenth century. Yet the republic survived anyway. This dissertation argues that Americans’ very desire for geopolitical independence explains their continued deference to European education. Rather than revolutionizing American social order, education became a primary means for reconciling traditional hierarchy with the republican political culture born of revolution.Based on archival research in over twenty libraries in eight states, this dissertation explains the origins of “monarchical education” in colonial America and explores the consequences of its persistence into the early republic. In particular, this dissertation focuses on academies, high-level secondary schools, in the mid-Atlantic and upper South from 1730 to 1810. The religious revivals of the Great Awakening fueled most of the early development of academies. Both British and colonial officials, though, sought to use education not only to establish domestic social order, but also to convince the world that British North America belonged in the world of “civilized nations.” The term “civilized nation” described societies that contained the requisite institutions, culture, and manners to follow the law of nations and command diplomatic recognition. Ironically, many of the colonists reared in this Europeanized educational culture became the vanguard of the revolutionary movement. Desperate to cement their independence, Americans in the early republic continued to use education to demonstrate that the United States was a “civilized nation.” This explains why early American educators continued the “absurdity of … copying the manners and adopting the institutions of monarchies,” as Webster noted. American independence rested on a foundation of conformity to European precedents. Large scale systems of public education did not emerge in first decades of independence. Instead, local civil associations and religious groups, with some state-level governmental support, built numerous academies throughout the region. In this way, local communities and state governments took part in the broader process of post-revolutionary state formation. At the same time, the broader goals of state formation impacted local education, often stifling curricular development and educational innovation. Ultimately, these educational practices undermined some of the Revolution’s most democratic impulses. Education shaped the structure of inequality on the grounds in hundreds of American communities, establishing the boundaries of participation in public life along explicit class and gender, and implicit racial, lines.

Excited State Dynamics of Bioinspired Materials: Triplet Formation in Silver(I) Mediated Cytosine Base Pairs and Chemical Disorder in Dopa Melanin

Kohl, Forrest Robert The Ohio State University ProQuest Dissertations & 2021 해외박사(DDOD)

The ability of DNA to resist photodamage has led to extensive study of its excited state properties. Most recently interest in metal coordinated DNA materials have led to a surge in study of the spectroscopic properties of Metallo-DNAs. In particular, Ag+ interactions with DNA have been of great interest to due to the non-canonical base pairs, such as cytosine-cytosine, formed through Ag+ binding and the ability to form reduced silver nanoclusters which could potentially operate as biosensors. In this text the relationship between structure and photophysics is explored for a Ag+ bound all-cytosine oligonucleotide dC20 as well as Ag+ bound cytosine and Ag+ bound cytidine monomers. Using circular dichroism and UV-Vis-NIR transient absorption spectroscopy, in conjunction with TDDFT calculations carried out by our collaborator Prof. Lara Martinez-Fernandez, it is shown that addition of silver nitrate to dC20 (Ag+-dC20) solutions leads to the formation of parallel duplexes which contains Ag+ mediated cytosine-cytosine base pairs with a high degree of propeller twist. The Ag+-dC20 duplexes are found to form an unusually long-lived state which persists beyond our time window (>4 ns). This state is unobserved in i-motif and single stranded forms of dC20. Furthermore, the state is absent in solutions of Ag+ bound cytosine monomers which are expected to form planar base pairs than can potentially form sheets or ribbons, indicating that propeller twisting is leading to the formation of this long-lived state.The identity of this long-lived species in Ag+-dC20 was investigated using FTIR and time resolved infrared spectroscopy (TRIR) with aid from QM/MM calculations carried out by our collaborator Prof. Lara Martinez-Fernandez. In addition to Ag+-dC20, Ag+ bound cytidine monomers (Ag+-Cyd) and cytosine monomers (Ag+-Cyt) were studied which are expected to form propeller twisted and sheet like structures, respectively. The long-lived state, which is found to also form in Ag+-Cyd but not Ag+-Cyt, is found to be a triplet excimer state which forms via a charge transfer state between a single cytosine and a bound Ag+. The formation of triplet states in the yield seen here is atypical of DNAs and triplet state are believed to play a role in the formation of cyclobutene pyrimidine dimers (CPDs). However, despite the relatively high amount of triplet formed, no increase in photodegradation is seen. We postulate that propeller twisting lowers triplet excimer energy leading to a decreased likelihood to form CPDs through triplet formation. The formation of the triplet in Ag+-dC20 and Ag+-Cyd and the lack of triplets in Ag+-Cyt further indicates that propeller twisting is key to formation of the triplet excimer in these Ag+-bound cytosine rich systems.In addition to studies on metallo-DNA systems, a biologically inspired melanin analogue DOPA-Melanin (DOPA-Mel) was studied in order to investigate how the expected chromophore heterogeneity in the system influences its ability to operate as an effective sunscreen. Eumelanin is believed to consist of a multitude of different chromophores leading to a broad and featureless UV-Visible absorption spectrum. Due to the uncertainty of its structure the precise mechanisms surrounding the sun screening ability of eumelanin remain uncertain. Broadband UV-Vis-NIR transient absorption spectroscopy was used to investigate the excited state behavior of various subsets of DOPA-Mel chromophores by using several excitation wavelengths from 265 to 600 nm. The procedure led to clear observations of transient spectral hole burning with holes of linewidths of 0.6 eV tracking with the pump wavelength. Observation of these holes is direct conformation of a high degree of chemical disorder in DOPA-Mel, but these chromophore subsets are found to have identical kinetic decay profiles. The commonality of the transient kinetic decays in addition to the broad common transient spectrum was assigned to the formation of charge transfer states between adjacent chromophores. Finally, the parallels between graphitic carbon materials and melanins are discussed suggesting commonalities in structure.

Managing Forests and Understanding Social Intolerance for Ohio's Declining Timber Rattlesnakes

Hoffman, Andrew Stewart The Ohio State University ProQuest Dissertations & 2021 해외박사(DDOD)

Reptiles and amphibians are in rapid, global decline but these declines are regionally and taxonomically disproportionate. North American pit vipers have low fecundity and rely on high adult survivorship, making them particularly vulnerable to anthropogenic threats. The rare, but potentially fatal consequences of human-viper interactions further compound this threat by increasing persecution and decreasing human tolerance for snake populations. The timber rattlesnake (Crotalus horridus) is the most broadly distributed venomous snake in North America, but has declined dramatically, especially at the periphery of its range in states like Ohio. Remaining populations in Ohio are largely found on relatively remote and expansive tracts of public land in the southeastern part of the state. These forests are managed for recreation, ecological diversity, and resource extraction (timber harvest), but the effects of silvicultural practices employed here are generally unknown for rattlesnakes.From 2016–2020, we captured and tracked timber rattlesnakes using VHF radiotelemetry to measure their habitat use in the context of disturbance-mediated changes to forest structure from past silviculture treatments and timber harvest. We also extensively monitored snakes during spring egress and fall ingress with radiotelemetry and game cameras to better understand spring and fall phenology and quantify their risk of exposure to prescribed fire. Finally, we surveyed Ohio residents during 2020 to measure their tolerance for rattlesnakes in Ohio and test psychological models of tolerance commonly used to better understand tolerance and risk acceptance of large, predatory mammals.We tracked 43 timber rattlesnakes multiple times per week for time periods ranging from a month to up to three years. Snakes at our study site disproportionally used warmer parts of the landscape with greater solar radiation, higher mean tree basal area (larger trees), and more disturbance (lower canopy height). However, behavior and physiological state strongly mediated this trend with snakes selecting warmer and more heavily disturbed sites when thermoregulation was a priority (e.g., gestation, ecdysis) and more moderate temperatures when foraging. We also evaluated forest structure and composition metrics commonly used in the silvicultural decision support system SILVAH, but most (tree diversity, oak dominance, total DBH, total basal area) were not good predictors of site use. However, snakes were more likely to use sites with relatively low tree density, along upper slopes and on ridges making both relative tree density and ELTP (Ecological Land Type Phase) good predictors of snake site use.We were also able to model rattlesnake ingress and egress at our site using meteorological variables, but day of year was the most important variable in the model with temperature also having a modest effect on fall and spring phenology. Though the beginning of the state’s fall burning season (October 15th) overlapped aboveground activity, on average, for about half of our telemetered snakes, there was relatively little aboveground snake activity prior to the end of the spring burning season (April 15th). Additionally, we used our model to retrospectively predict the risk of exposure for rattlesnakes in southern Ohio during 12 previous prescribed burns and found that risk of exposure, on average, was low (< 30%) for a snake located within a burn unit.Finally, we collected 447 responses from our survey of Ohio residents’ attitudes toward rattlesnakes and were able to predictively model tolerance for rattlesnakes in Ohio using a psychological model of wildlife tolerance. However, our model only predicted the acceptable population level for rattlesnakes in Ohio (wildlife stakeholder acceptance capacity) but did not effectively predict acceptance or stewardship. Respondents were more likely to tolerate larger rattlesnake populations if they perceived more benefits and fewer risks from the presence of rattlesnakes. Their perceptions of risks were negatively affected by their attitude toward rattlesnakes and positively affected by their domination-oriented wildlife values and their perceptions of benefits were positively associated with their attitude toward rattlesnakes.This research has generated the largest and most detailed dataset on any Ohio rattlesnake population and provides insight into their management. Timber rattlesnakes had relatively broad habitat associations and seemed to be minimally affected by past and present land use practices. In fact, we found that snakes were more likely to use sites with a recent history of canopy disturbance, likely due to thermoregulatory benefits. Our observations indicate most snakes do not emerge from hibernacula until after the close of Ohio’s burn season (April 15th) and snakes out before this date are more likely to be sheltered and at lower risk from fire. Ongoing forest management activities are therefore unlikely to negatively impact rattlesnake populations. However, intolerance of rattlesnakes in Ohio and resistance to their conservation may present a more substantial barrier to recovering the species in the future. Although sound land management should ensure the stability of remaining populations, broader population recovery in Ohio will be difficult without outreach efforts aimed at reducing intolerance for these now rare snakes.

Community Health Centers and Medicaid Expansion: Historical Reflections, Policy Effects, and Care Delivery after the Affordable Care Act

Goldstein, Evan Victor The Ohio State University ProQuest Dissertations & 2020 해외박사(DDOD)

The federally-funded health center program aims to deliver high-quality, culturally-competent primary health care services, as well as ancillary health and supportive services, such as care coordination, health education, and oral health care, to all persons regardless of their ability to pay. Federal funding for community health centers (CHCs) has been uncertain for decades. The Affordable Care Act (ACA) Medicaid expansion provided CHCs with new opportunities to expand their patient revenue, broaden their reach, and fulfill their mission. However, relatively little is understood in the scholarly literature about how the ACA Medicaid expansion affected care delivery at CHCs, especially beyond the first few years, post-expansion. In this dissertation, I attempted to examine aspects of health care utilization and quality of care at CHCs following the ACA Medicaid expansion, and in a broader sense, to explore in different ways whether the ACA Medicaid expansion helped facilitate CHCs’ pursuit of mission.Chapter 4 examined whether the ACA Medicaid expansion created lasting increases in the percentage of CHC patients covered by Medicaid and lasting decreases in the percentage of uninsured adult CHC patients in expansion-state CHCs, compared to non-expansion-state CHCs. The results of the study showed that, on average, Medicaid expansion increased Medicaid coverage among adult CHC patients in the expansion-state CHCs by 12.0 percentage points and decreased uninsurance among adult CHC patients by 7.7 percentage points by 5-years post-expansion, compared to non-expansion-state CHCs. Moreover, the predicted percentage of expansion-state CHC adults covered by Medicaid increased to a peak at 2-years post-expansion and then slightly decreased and plateaued from 3-to-5-years post-expansion. Expansion-state CHCs retained most expansion-covered patients over time, and greater state-level enrollment efforts were shown to be important for enrolling Medicaid-covered CHC patients.Chapter 5 examined whether expansion-state CHCs were more likely to deliver preventive fluoride varnish (FV) treatment and dentistry services over longer periods following Medicaid expansion compared to non-expansion-state CHCs. The results of the study showed that expansion-state CHCs provided FV at rates greater than that of non-expansion-state CHCs at 2-years and 3-years post-expansion, respectively. Therefore, following the ACA Medicaid expansion, it appears CHCs were able to not only able to expand services to fill gaps in providing medical services, but also expansion-state CHCs were able to increase the delivery of preventive oral services compared to non-expansion-state CHCs. In contrast, expansion-state CHCs were less likely than non-expansion-state CHCs to provide dental restorations and oral surgery following the Medicaid expansion: Expansion-state CHCs provided oral surgeries at lower rates than non-expansion-state CHCs at 2-years post-expansion.Chapter 6 explored whether rural CHCs served smaller or larger lesbian, gay, and bisexual (LGB) patient populations compared to metropolitan CHCs in the post-ACA era. Chapter 6 also examined, among CHCs serving LGB patient populations that were comparatively larger and nationally-representative of the general LGB population in size, whether rural CHCs provided lower-quality treatment for HIV infection and depression compared to metropolitan CHCs in recent years. Findings from the study suggested that, on average, rural CHCs served smaller LGB patient populations than metropolitan CHCs in each year of the study. Yet there were no statistically-significant differences in HIV infection or depression care quality between rural and metropolitan CHCs serving comparatively larger LGB patient populations. Beyond access to care, in the post-ACA era it does not appear geographic location of residence exacerbates disparities in treatment quality at CHCs among CHCs serving relatively larger LGB patient populations, at least not for two services that remain critically important for the wellbeing of many LGB persons.CHCs have long endured financial and political uncertainty. Without a doubt, financial uncertainty continues to vex CHC managers and their stakeholders today. Aside from known federal and local funding challenges, new unknowns and negative macroeconomic conditions will undoubtedly emerge in the future. For example, how will the looming federal court decision on the constitutionality of the ACA affect CHCs? Or how will the 2019-2020 coronavirus (COVID) pandemic affect CHCs? These and other not-yet-known questions will be dealt with in time. However, one thing is certain: Today, over 1,300 CHCs comprise a durable federal program – a program that is unlikely to either die outright or significantly change, especially as CHCs continue to demonstrate success in pursuing their underlying common mission.