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The Doctrinal Justification of Finite Pluralism in Epicurean Physics
No full textIn this paper, I examine and evaluate the doctrinal background that warranted the assertion of finite pluralism, or the teaching that there are a finite number of possible atomic shapes, in Epicurean physics. The examination centers on the Epicurean doctrine of minima, or smallest parts or measures of magnitude, reconstructing and evaluating the arguments given by Epicurus in the Letter to Herodotus and by Lucretius in the De Rerum Natura. I also examine the doctrine of limitation of actual atomic sizes and auxiliary arguments by Lucretius which make use of unique metaphors and terminology. I identify four main problem areas in the combined Epicurean-Lucretian account, evaluate the effect of those problem areas on the viability of the finite pluralist doctrine, and give possible Epicurean responses to the objections. I identify two general areas which the doctrine of minima does not address in either Epicurus’ or Lucretius’ work, explore possible answers to the questions, and evaluate their implications. I ultimately conclude that the potential failure of the Epicurean account of minima and/or actual atomic sizes does not necessitate the abandonment of a finite pluralist position, though it may preclude arrival at the finite pluralist conclusion by means of the Epicurean argumentative process
Quantifying Temperature Effects on Developmental Rate and Plant Quality of Compact Container-grown Tomato (Solanum lycopersicum)
Get PDFMean daily temperature effects on plant development rates and quality were evaluated for compact container-grown tomato (Solanum lycopersicum). Compact tomato varieties ‘Siam’ and ‘Red Velvet’ were grown in greenhouses at 18 to 26 °C (Experiment 1) and 20 to 30 °C (Experiment 2) under supplemental high-pressure sodium lighting and 16-hour photoperiod. The number of days to first open flower, first ripe fruit, and from flower to ripe fruit were measured and development rates calculated by taking the reciprocal (e.g. 1/days). Temperature effects were predicted by fitting a linear (for first open flower) and a nonlinear exponential function (for first ripe fruit and between first open flower and ripe fruit) which included base temperature (Tmin) and maximum developmental rate (Rmax) parameters. Plant quality attributes were measured in Experiment 2. As temperature increased, the time to flower and fruit decreased (i.e. developmental rates increased) for both varieties. Estimated Tmin was 8.7 °C for ‘Siam’ and 11.4 °C for ‘Red Velvet’ whereas Rmax was similar between varieties (0.030 at fruit, and 0.037 from flower to fruit). ‘Siam’ and ‘Red Velvet’ grown at ≈25 °C had a relatively short crop time, compact canopy, adequate fruit size, and a high number of fruits per plant at finish. Compact tomatoes are new crops being grown by greenhouse floriculture operations for ornamental and edible value, and the information from this study can help growers schedule these crops to meet critical market windows and determine the impacts of changing growing temperature on crop timing and quality
Evaporating Natural Parent Childcare Liberties Under New Parentage Laws
Get PDFThis Article explores the evaporating Due Process interests of natural childcare parents who are not unfit and who do not knowingly consent to diminished childcare liberties when the state recognizes new nonadoptive and nonbiological parents. Childcare liberty losses need not involve neglect or comparable bad acts rendering a parent unfit. They need not involve consent, actual or implied, by an adversely affected parent. On the new forms of nonadoptive and nonbiological childcare parents, the most recent UPAs and their state counterparts are illustrative. They recognize parentage in an individual who resides with and holds out a child as the individual’s own “for the first two years of the life of the child.” That individual can effectively replace a fit, existing, and nonconsenting parent by judicial decree. Comparably, the 2017 UPA recognizes that a de facto parent, without adoptive or biological ties, can then replace an existing fit parent. Further, nonadoptive and nonbiological parents can also effectively displace natural parents via new forms of voluntary parentage acknowledgments. This Article also explores Due Process liberty issues arising with the new forms of parentage under the United States Supreme Court decision in Lehr v. Robertson. There, as noted, the Court recognized that a “natural father [has] an opportunity that no other male possesses to develop a relationship with his offspring.”
This opportunity interest in childcare parentage has been extended to at least some “natural” mothers (i.e., egg donors who are not gestating parents). The new parentage forms can negate the parental opportunity liberty interests of some expecting natural parents, including sperm or egg providers. Upon reviewing the new parenthood forms and their current federal and state law limits, this Article concludes with reflections on the need for greater legal protections for existing and expecting natural childcare parents when new forms of nonadoptive and nonbiological childcare parenthood are undertaken. Further, this Article demonstrates how to better safeguard the childcare liberties of natural parents
Exploring Full-time Female Faculty Members’ Experiences with Institutional Climate in Rural Arkansas Community Colleges: A Preregistered Study
Get PDFThe current literature implies that female faculty in community colleges often endure a chilly organizational climate of marginalization. This marginalization makes female faculty more likely to leave higher education than male colleagues because of a lack of appreciation and recognition. This qualitative exploratory multiple-case study (preregistered study) uses the Job Embeddedness Theory as its conceptual framework. It explores full-time female faculty members’ (F-TFFMs) experiences with institutional climate in rural Arkansas community colleges to understand their motivations to teach in the setting and the reasons they choose to stay in their position. Findings from this study will show F-TFFMs motivations to teach and reasons for staying in rural Arkansas community colleges and can help institutions understand F-TFFMs experiences with institutional climate. Keywords: history of community colleges, women’s educational history, community college missions, organizational climate, rural communities, Arkansas community colleges, and female faculty, higher education, retention, turnover, attritio
Quick Response Codes in Extension Outreach Communications: Insights from a Visual Content Analysis and Educators’ Perceptions
Get PDFIncreased smartphone use presents an opportunity to enhance the creative inclusion of Quick Response (QR) codes in extension outreach efforts. Tailoring extension programs to communicate with specific audiences has been identified as essential, highlighting the need for targeted and context-specific strategies. The development of QR code technology has provided a unique approach that allows extension professionals to target clientele with specific extension messages and programs. While extension has a commendable record in educational delivery through traditional forms of outreach, research on how best to employ digital tools with extension audiences is thin at best. Though the rising popularity of QR codes for information exchange is certain, there is still a gap in knowledge about the factors influencing their acceptance and usefulness in extension outreach. Employing social science methodologies including content analysis and semi-structured interviews, this dissertation study assessed the current QR code usage in extension outreach media outlets and described extension agents’ perceptions through semi-structured interviews in the Ozark district of Arkansas. The first article of this study incorporated a content analysis of 105 extension outreach graphics to assess the placement of codes in the outreach communications. The second article was a qualitative study, involving semi-structured interviews with twelve extension professionals. The study shed light on agents\u27 perceptions, adoption patterns, and challenges related to QR code usage. This formative study ascertained local perspectives and priorities, which could then be used to drive communication strategies. It is envisaged that the findings and recommendations of this study will lead to the development of a framework that can be utilized to improve audience-specific communication programming and strategies throughout the area in the southern region where the research was conducted
Elucidating the Mechanisms of Collagenase H from \u3ci\u3eHathewaya (Clostridium) histolytica\u3c/i\u3e in Collagen Degradation and Developing a Cross-linked Platform for Efficient Capture and Release of Adeno-Associated Virus Serotype 2 (AAV2)
No full textIn biological systems, Hathewaya (Clostridium) histolytica secretes collagenases that degrade structural collagen in host tissues and cause tissue necrosis. Despite their detrimental effects, these enzymes have significant therapeutic potential by effectively digesting various collagen subtypes to treat connective tissue disorders. The bacterium produces two homologous collagenases, ColG and ColH, with a catalytic module crucial for hydrolyzing collagen and binding domains, including collagen-binding domains (CBDs) and polycystic kidney disease-like domains (PKDs), for substrate interaction.
Although the crystal structure of the catalytic module of collagenase G (ColG) has been determined, shedding light on its chew-and-digest mechanism, the structure of collagenase H (ColH) remains unknown, limiting a deeper understanding of its catalytic mechanism. In this study, the structure of the ColH catalytic module was resolved in an unprecedented “closed” conformation using X-ray crystallography. Heteronuclear Single Quantum Coherence (HSQC) Nuclear Magnetic Resonance (NMR) spectroscopy further elucidated how ColH recognizes and unwinds collagen triple helix for endopeptidase activity. Small-angle X-ray scattering (SAXS) demonstrated how ColH binds to mini-collagen to feed the catalytic module with the substrate for digestion. Together, these findings provide a comprehensive understanding of ColH’s role in collagen degradation, which would help develop more effective therapeutic agents.
Also, a heparin-crosslinked membrane platform was developed for the large-scale purification of viral vectors. This platform can capture adeno-associated virus serotype 2 (AAV2) particles and release them on demand, which could be helpful for gene therapy applications
Repurposing High-Expressing Muscle Loci with CRISPR Gene Editing: A Multi-Platform Analysis at Efficiency and Safety
No full textThis dissertation presents the development and evaluation of a CRISPR/Cas9-based platform for targeted gene integration as a therapeutic strategy for loss-of-protein diseases. By repurposing highly expressed muscle loci, such as Ckm, this platform demonstrates potential for stable therapeutic RNA expression. In vitro and in vivo studies were conducted to validate its efficiency and assess the safety of the selected integration sites, with particular focus on the effects of double-strand break (DSB)-mediated targeted gene insertion.
The first aim establishes proof-of-concept for the targeted integration of therapeutic genes into high-expression muscle loci using Homology-Independent Targeted Integration (HITI), achieving high RNA expression with minimal adverse effects on the global transcriptome. The second aim examines the transcriptomic consequences of HITI-mediated gene editing, using short-read and long-read sequencing to evaluate integration precision, transcript diversity, RNA modifications, and unintended integration events. The third aim applies similar orthogonal short- and long-read sequencing approaches to investigate Duchenne Muscular Dystrophy (DMD), the most common genetic disorder. In this section, we investigate the genomic and transcriptomic safety of AAV-CRISPR delivery for DMD therapy, identifying complex structural variations and unexpected AAV insertions that might be overlooked by a single sequencing method.
Collectively, these studies demonstrate the potential and challenges in developing targeted integration mediated by CRISPR-based therapeutics and highlight the value of comprehensive sequencing methodologies to advance gene editing safety and reliability
Molecular Mechanisms Underlying Social Learning in the Butterfly \u3ci\u3eBicyclus anynana\u3c/i\u3e
No full textLearning plays a critical role in shaping behavior, such as influencing survival and reproduction. One particularly important form of learning is mate preference learning, which allows individuals to alter their mate preference based on prior social experience. Among the different types of mate preference learning, imprinting, where early exposure to specific mating cues influences later mate choice, has been widely studied. This process is important in the context of reproductive isolation and speciation, as learned preferences can reinforce or alter eventual mate choice, potentially leading to genetic divergence between populations. Despite its importance, the molecular mechanisms underlying mate preference learning remain largely unexplored. In this dissertation, I explore the genetic and neurogenomic basis of mate preference learning using Bicyclus anynana, a butterfly species that exhibits the ability to learn mate preferences based on early social exposure. I address four key questions: (1) How does the duration of social exposure influence mate preference learning and associated gene expression? (2) What are the molecular pathways underlying positive and negative valence attribution in learned mate preferences? (3) Does the pigmentation gene yellow, known for its pleiotropic role in coloration and courtship, also modulate mate preference learning? (4) How do temporal patterns of gene expression in antennae influence female antennal receptivity? To address these questions, I used behavioral assays, transcriptomic analyses, and genome editing. This integrative approach allows me to identify candidate genes and molecular pathways involved in mate preference learning. By elucidating the genetic architecture of mate preference learning, this research advances our understanding of how learned mate preferences can contribute to reproductive isolation and speciation at a molecular level