Investigating environment-friendly diet formulation strategies

Ragland, Darryl Purdue University 1999 해외박사(DDOD)

Nitrogen and phosphorus from animal waste and agricultural by-products can profoundly impact water and soil quality. Diet formulation on a digestible amino acid basis reduces nitrogen excretion. Formulation on a digestible amino acid basis requires reliable estimates of amino acid digestibility. Apparent ileal digestibility of amino acids in corn, pearl millet, oat groats, sorghum, and soybean meal was measured in barrows using the difference method of diet formulation. The results indicate that the difference method of diet formulation represents a viable application for assessing amino acid digestibility of feedstuffs in pigs. True digestibility of amino acids in corn, soybean meal, and wheat by-products (bakery meal, red dog, wheat middlings) used in duck diet formulation was assessed. Cecectomized and intact ducks were subjected to precision feeding and collection methodologies to evaluate the influence of hindgut microflora on nutrient digestibility. The results suggest that variation in amino acid digestibility between cecectomized and intact ducks is considerable for low-protein ingredients, but differences in digestibility are less pronounced with higher amino acid intakes. Similar precision feeding and collection methodologies were employed to characterize the metabolizable energy (ME) of several cereal grains (corn, barley, pearl millet, sorghum, triticale). The study demonstrated the potential utility of pearl millet and sorghum in feed formulation for ducks based on comparable ME to corn. Some agricultural wastes are characterized by high nitrogen and phosphorus contents. Swine and duck nutrient balance assays were employed to evaluate co-products from a pork processing plant and a commercial microbial fermentation unit. The fermentation co-product was observed to have no feeding value due to poor ability to support nitrogen retention in pigs and ducks. Antinutritional compounds restrict the use of certain ingredients in diet formulation by exerting negative effects on nutrient availability. The effect of new xylanase and phytase preparations on performance of young pigs was investigated. Xylanase in a corn-soybean meal diet failed to influence pig performance, but improvements in growth and feed efficiency were effected by phytase addition to diets. In conclusion, incorporation of nutrient digestibility and exogenous enzyme research findings in commercial diet formulation will aid efforts to reduce the negative environmental impact of animal production.

Sustaining Black Captivity: A Critical Analysis of Corporate Philanthropic Discourse on Education

Ragland, Allison The Ohio State University ProQuest Dissertations & 2019 해외박사(DDOD)

Industrial and corporate philanthropy have historically played a role in shaping and supervising the education of African American students. This role includes promoting certain types of education for Black students and upholding certain ideologies within the Black community, most of which are rooted in Black subservience and result in the circumvention of radical demands for Black liberation. This study examines the supervision of Black education as a form of surveillance through a critical analysis of corporate philanthropic discourse. In this dissertation, I use critical discourse analysis to explore the ways that the discourses of neoliberal education reformers from the corporate sector uphold the ideological surveillance of Black students and the role of those discourses in sustaining Black captivity. I identify three salient narratives in the discursive samples I analyzed, including A) the problem is simple.

Experimenting with chemical bodies: Science, medicine, and philosophy in the long history of Reinier de Graaf's experiments on digestion, from Harvey and Descartes to Claude Bernard

Ragland, Evan R Indiana University 2012 해외박사(DDOD)

This study follows the long history of an experiment from the sixteenth to the mid-nineteenth centuries. Historians have produced long histories of scientific ideas and local histories of scientific practices. Here, combining intellectual and cultural historical approaches allows us to follow practices diachronically across contexts. The medical and philosophical investigations and controversies in and around the work of Franciscus Dele Boë Sylvius constitute the local prehistory. Following William Harvey, Sylvius and colleagues such as Johannes Walaeus developed novel methods for generating medical and philosophical knowledge from experimentation. They often mutually opposed prominent Cartesians, such as Cornelis van Hogelande, who privileged ratiocination over experimentation. Sylvius's clinical pedagogy and medical and chymical experimentation provided the inspiration for Reinier de Graaf's work. Student disputations—most authored by the students—from Leiden offer a new picture of the competitive, collaborative, and highly experimental culture of students and professors. Merging chymistry and anatomy, de Graaf constructed and used hybrids of chymical instruments and living dogs like chymical distillation furnaces for the production of the supposedly acidic pancreatic juice. Former friends and distant foes attacked de Graaf's claims to the matters of fact about the pancreas and its juice. Florentius Schuyl, Johann Conrad Brunner, and Johannes Pechlin receive new analyses here. Sylvius's acid-alkali medicine, rooted in Joan Baptista van Helmont's medical chymistry, persisted among a family of similar chymical systems. This study reveals the important role of taste in assaying chymical substances, and the often disgusting and uncivil nature of early modern European medical experimentation. De Graaf's experiment re-emerged in the early nineteenth century, as physiologists used his approach to solve problems in their own discipline. Even Claude Bernard used de Graaf's methods, and extended the older styles of experimentation into the milieu intérieure and his new scientific medicine. De Graaf's work on the pancreas and its juice remained his icon of the experimental approach to the medicine and science of living bodies. Tracking the history of de Graaf's experiment affords new insights into the nature of early modern experimental culture, the status of experiments as historical entities, and the origins of modern experimental medicine.

Razor wire cuts both ways: Teaching inside a juvenile institution

Ragland, Betty B The University of Tennessee 2005 해외박사(DDOD)

The researcher is an educator working in a juvenile correctional facility. In this study she invited 12 of her colleagues as co-researchers to explore their shared practice and to foster change in the workplace culture. Each participant engaged in a phenomenological interview designed to elicit perceptions of teaching in a correctional institution. The researcher then facilitated group sessions in a collaborative learning effort to construct shared meaning of their joint practice. Follow-up interviews, as well as thematic and language analysis of data obtained from audiotaping and transcribing interviews and group sessions, suggest changes in participants' perceptions of their practice and of their colleagues. Themes developed across data sets include perceptions of the environment, both inside and outside the institution; relationships with others---including students, colleagues, and family members, and personal experience of the practice, all of which are subject to struggles or battles. The length of time engaged in the practice influences how each of these themes is experienced. The use of metaphors and of personal pronouns is also examined; results indicate that the form of participant comments is congruent with the content of those comments. By engaging in collaborative learning in eight group sessions over three months, participants were able to construct joint understandings about their shared experience. These understandings were expressed in terms of knowing where we are coming, from, making sense of our experience, and recognizing the shape of our experience. This study suggests implications for workplace culture change initiatives in other settings.

On generalizations of finite groups in which normality is a transitive relation

Ragland, Matthew F University of Kentucky 2005 해외박사(DDOD)

A group G is called a Hallchi-group if G possesses a nilpotent normal subgroup N such that G/N' is an chi-group. A group G is called an chio-group if G/phi(G) is an chi-group. The aim of this work is to study finite solvable Hallchi-groups and chio-groups for the classes of groups T , PT , and PST . Here T , PT , and PST denote, respectively, the classes of groups in which normality, permutability, and Sylow-permutability are transitive relations. Finite solvable T -groups, PT -groups, and PST -groups were globally characterized, respectively, in [13], [29], and [1] whereas local characterizations were given, respectively, in [23], [6], and [4]. Here we arrive at similar global and local characterizations of finite solvable Hallchi-groups and chio-groups where chi ∈ { T , PT , PST }. Chapter one is concerned with background information on the classes T , PT , and PST . In chapter two, both the global and local characterization theorems for Hallchi and chio are given. A key result aiding in the characterization of these groups is that they possess a nilpotent residual which is nilpotent and a Hall subgroup of odd order. The main result shown here is that HallPST=To for finite solvable groups. Chapter three discusses minimal-non-chi-groups and the concept of subgroup-closure for the classes of groups under consideration. One main result shown here is that finite subgroup-closed HallPST -groups and finite solvable PST -groups are one and the same. The other main result is that finite minimal-non- HallPST -groups are precisely the minimal-non- PST -groups.

Race and gender differences in factors influencing romantic commitment among college students

Ragland, Lynelle Monique The University of North Carolina at Chapel Hill 2002 해외박사(DDOD)

Prior investigations have indicated that African Americans are having increasing difficulty establishing and maintaining committed and satisfying relationships. However, few studies have examined this theory empirically. The present study examined the relationship between early environmental influences (e.g., attachment to parental figures, socialization), cognitions about relationships, and commitment. A theoretical model of commitment was tested, which was partially supported, with important gender differences. The results indicated that positive socialization experiences and the quality of one's own romantic relationship history are the most salient factors related to commitment for both genders. However, cognitive mediation between early experiences and commitment only occurred in females, suggesting that females engage in more cognitive relationship processing than males. Additional gender differences in the model are discussed. Race differences with regard to the early environmental experiences were also found. Expected race differences emerged, with African Americans, as compared to Caucasians, reporting less positive and more negative socialization experiences, less positive and more negative attachment histories with fathers, and more negative romantic relationship histories with significant others. Expected race differences also emerged with regard to the cognitive variable of expectancies, with African Americans reporting less positive expectancies of the opposite gender in the context of a relationship. However, an unexpected race difference emerged in the cognitive variable of assumptions, with Caucasians, as compared to African Americans, endorsing more negative assumptions about the opposite gender of the same race. A final unexpected finding was that no significant differences emerged between racial groups on attitudes toward commitment. Results are discussed with regard to the commitment model, race, and gender differences. Clinical implications and future research directions are also discussed.

Life history evolution in seasonal environments: Phenological and environmental determinants of thermal adaptation in Wyeomyia smithii

Ragland, Gregory J The University of North Carolina at Chapel Hill 2007 해외박사(DDOD)

Environmental variation poses a major evolutionary challenge to organisms. This is particularly true for seasonal environments where environmental factors fluctuate radically but predictably on an annual basis. Dormant life history stages often evolve to mitigate exposure to harsh seasonal environments (e.g., winter). In addition, norms of reaction, or the relationship between phenotype and environment, often evolve as a response to local environmental heterogeneity. My thesis explores how the seasonal timing of dormancy affects selection on reaction norms of active, non-dormant life history stages in temperate insects. Changing the dates of initiation and termination of winter dormancy changes the thermal habitat experienced during active growth and reproduction. Thus, geographic variation in the timing of dormancy complicates geographic patterns of thermal selection on active life history stages. Using available inter- and intraspecific life history data in conjunction with long-term weather data, I show that geographic clines in dormancy timing cause populations along the cline to experience similar exposure to cold temperatures during active growth. As a result, strong latitudinal trends in the timing of dormancy predict weaker latitudinal trends in thermal adaptation of active stages. I further illustrate this concept by examining geographic variation in the timing of winter dormancy, thermal sensitivity of development, and tolerance to thermal stress in the pitcher plant mosquito, Wyeomyia smithii. The results from W. smithii suggest that selection applied specifically by the thermal environment of the growing season best explains geographic variation in the thermal sensitivity of development time. In contrast, geographic variation in the thermal environment of the entire year best explains geographic trends in thermal stress tolerance of active life history stages. These results suggest two major conclusions. First, thermal sensitivity and thermal tolerance can exhibit local adaptation in populations that also demonstrate local adaptation in diapause timing. Thus the evolution of one type of adaptation does not preclude the other. Second, dormancy timing unquestionably influences direct selection on active life history stages, but correlated selection on overwinter survival may strongly influence temperature tolerance of active life history stages.

Mechanisms of common fragile site instability and cancer

Ragland, Ryan L University of Michigan 2009 해외박사(DDOD)

An increase in DNA damage is an "enabling characteristic" in tumorigenesis, and normally occurs at loci called common fragile sites (CFSs), or by the loss of genes involved in the DNA damage response pathway. CFSs are a normal part of the human genome, and are exceptionally prone to DNA damage under conditions of replication stress, such as treatment with low concentrations of the DNA polymerase inhibitor aphidicolin. While much has been learned about the cellular responses to DNA damage at CFSs, less is known about what makes these sites inherently unstable. To determine if the sequence of CFSs is causal to their instability, BACs containing CFS sequence were stably transfected into HCT116 cells, and cell clones with BACs integrated at ectopic non-fragile loci were isolated. Cell clones containing integrated CFS BACs showed a significant increase in aphidicolin-induced DNA damage at the integration site, compared to control BACs. This is the first direct evidence in human cells that introduction of CFS sequences into ectopic non-fragile loci is sufficient to cause CFS-like instability. These data support the hypothesis that sequences at CFSs are inherently unstable, and are a major factor in the formation of replication stress induced gaps and breaks at CFSs. A primary responder to DNA damage at CFSs, the protein kinase Ataxia-telangiectasia and rad3-related (ATR) is responsible for sensing and signaling DNA damage associated with stalled replication forks. The role of ATR and the maintenance of damage at CFSs, in tumorigenesis is not well understood due to the lethality of complete loss of ATR and is best studied in vivo. To overcome this limitation, we created a viable mouse model with a hypomorphic Atr mutation and an estimated 66-82% reduction in Atr protein levels. These mice exhibited increased APH-induced DNA damage and checkpoint abnormalities indicative of Atr deficiency. Creation of a mouse model with hypomorphic Atr expression will serve as a valuable reagent to study the biological effects of Atr deficiency in vivo.

Racial Battle Fatigue and Graduate Student Roles: The Experiences of Black/African American, Biracial Black, and Multiracial Black Identified Students

Woods, Catherine Cheresse Ragland ProQuest Dissertations & Theses University of Oreg 2019 해외박사(DDOD)

Black students continue to endure racialized experiences in their pursuit of higher learning. Students' educational experiences, especially at historically White institutions, are plagued by incidents of racial microaggressions and racial stress, which in turn result in students' experiences of racial battle fatigue (RBF.