It is known that nerves are particularly critical during the early or dedifferentiative phase of limb regeneration. During this period in the innervated limb, cells just proximal to the amputation surface dedifferentiate, migrate to the limb tip, and undergo mitosis. These processes give rise to a population of undifferentiated mesenchymatous cells capable of redifferentiating into the missing components of the newly forming regenerate. The consequences of denervation stand in stark contrast to the normal events occurring in the innervated limb, because neither a blastema nor a regenerate forms. Results from this study indicate that during the early portion of the dedifferentiative phase in regenerates less than 2 3/4, days old the nerve apparently has little or no effect on the internal stump tissues. Of considerable interest in this regard is this study's documentation of a lack of neural influence on DNA synthesis and thus the cell cycle during the early dedifferentiative phase. Subsequently, during a transition period represented by 2 3/4 to 5 1/2 days regenerates there is some evidence for a neural influence on DNA synthesis in cells of the limb stump. Finally, on days 6 through 8, DNA synthesis is clearly nerve dependent. Since DNA synthesis is a prerequisite for mitosis, the depressed synthesis in a denervated limb precludes mitotic activity during the nerve-dependent, later portion of the dedifferentiative phase. Therefore, this research supports the idea that during the late dedifferentiative phase, including mound and early cone blastemal stages, there is a neural influence on the G1 or S phases of the cell cycle. This conclusion thereby makes progress toward explaining earlier observations of depressed mitotic activity during this period.

The ability for hematopoietic stem cells (HSCs) to regenerate the vascular and blood systems following injury suggests great potential for future therapies. Unfortunately, the various signaling pathways that regulate the regeneration of the adult HSC population in the bone marrow are not clearly understood. One of the proposed regulators for the regeneration of the hematopoietic system is an extracellular secreted protein R Spondin-2 (Rspo2), also known as roof plate-specific spondin-2. The novel interaction between the Rspo2 protein and c-kit+sca-1+lineage– (KSL) HSCs shows an increased number of KSL and of more differentiated hematopoietic stem and progenitor cells (HSPCs) in vivo during both the steady and injured states. To determine the most efficient concentration of Rspo2 for such an interaction to occur, various doses of Rspo2 recombinant protein are plated with the KSL cells. They are then examined through flow cytometry and colony forming cell (CFC) assay. Rspo2 is widely known to interact with the canonical Wnt3a protein to activate the beta-catenin pathway. However, when various concentrations of Rspo2 recombinant proteins are plated with the Wnt3a protein, the results show the opposite effect of plating the cells only with the Rspo2 protein. The overall increase in the total number of cells and KSL cells was concluded to be not significant. This study nonetheless provides the scientific community with a greater foundation for the usage of Rspo2 concentration for future experiments.

京都大学 / 新制・課程博士 / 博士(医学) / 甲第24992号 / 医博第5026号 / 新制||医||1069(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 後藤 慎平, 教授 安達 泰治, 教授 平井 豊博 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

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Bareroot, conventional containerized, and large potted EKOgrown® seedlings of water oak (Quercus nigra) and white oak (Q. alba) were planted on two Hurricane Katrina damaged sites in south Mississippi. After two growing seasons, white oak exhibited greater survival (61.1%) than water oak (48.8%) and greater height growth (WHO = 7.4 cm, WAO = 1.4 cm). Water oak had greater groundline diameter (GLD) growth (3.3 mm) and greater second-year height growth (WHO = 2.5 cm, WAO = 9.6 cm). Second-year development could lead to greater height growth by water oak. Bareroot seedlings outperformed other planting stocks in survival and height growth, but EKO seedlings exhibited greater GLD growth. Even though EKO seedlings had greatest GLD growth, they exhibited the least overall height growth of all planting stocks (1.9 cm). Based on seedling cost and performance in this study, planting bareroot seedlings are the most efficient method to artificially regenerate oak forests.

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Thesis advisor: Sarah K. McMenamin / Thesis advisor: Eric Folker / Resolving the mechanisms that orchestrate patterning in complex tissues – particularly how positional identity is instantiated, remembered, and directed – is imperative to understanding the morphogenesis of appendages. The zebrafish (Danio rerio) caudal fin skeleton is a powerful model to investigate these questions, as its precisely patterned bony fin rays are restored through regeneration. My aims in this thesis were to investigate the role of endocrine metabolic regulator thyroid hormone (TH) signaling during fin ray morphogenesis and how spatial identity is retained and redeployed during regeneration. I began my work by resolving TH signaling effects on the fin skeleton. Through nuclear receptor Thrab, TH acutely induces distal features in both development and regeneration (Chapter 2). To better understand how distal features are remembered, I established novel microsurgery techniques that would discriminate autonomous versus environmental components of ray patterning. While the rate of regeneration does appear to retain positional memory, I found ray patterning is instead informed by extrinsic cues (Chapter 3). During my investigation of TH activity in Chapter 2, I noted robust TH signaling in peripheral rays. Repurposing the microsurgeries developed in Chapter 3, I discovered this TH signaling is an inherent feature of peripheral rays, and this activity regulates local Notch pathway signaling (Chapter 4). My research has revealed many mechanisms—both dependent and independent of TH—that regulate fin ray patterning and how this positional identity is retained and redeployed during regeneration. / Thesis (PhD) — Boston College, 2024. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Biology.

Planning and design of brownfield landscapes are not straight forward due to invisible, potential contamination. The dilemma occurs to designers in dealing with brownfield landscapes, because they are unknowingly able to deliver deceptive information regarding the site safety. If the designers and planners are given the information about factors affecting people's reaction to different characteristics of brownfield landscapes, this would help them to be better prepared for ethical issues. For this study, visual preference survey for neighborhoods along the rail yard in the City of Roanoke was conducted. A dimensional analysis found six brownfield landscape types. First of all, historical landmark and maintained landscape types received the highest ratings regardless of the participants characteristics and backgrounds. These types may be viewed less critically and are thus likely to mask potential harms. Second, scruffy vegetation and modest rundown building types that made up the second preferred group revealed more ambivalent feeling. People were highly flexible in switching between change or preservation options in their thinking, thus it would be easy to lead people to focus on certain aspects according to the designer's purposes. Lastly, the two industrial remnant types were the least preferred group. Participants tend to associate these types with toxic pollutants that are likely to adversely affect the health, thus, it would be important to reassure people regarding safety concerns. The expert interviews with brownfield program managers of many localities (Roanoke, VA; Portland, OR; Toledo, OH; Pheonix, AZ; Lewisville, TX; Arlington, TX; and New Bern, NC) were conducted to determine whether the current approaches are effective and develop recommendations. The interviews found that the effectiveness of program is greatly challenged by normative site assessment required by federal government. While the procedure provides necessary information about site safety, it also attaches a stigma to sites regardless of actual contamination level. Based on the findings, it is recommended to include assessment criteria that reveals reuse potentials of brownfields for balanced approach. The results provide useful information for program managers, planners and designers regarding important factors that should be considered for site prioritization and preparation and presentation of designs for brownfield reuse. / Ph. D.

Yes / This seminar paper analyses the links between regeneration and international development, and describes project approaches in international development. In the light of these two perspectives it then goes on to discuss the main issue facing management of development or regeneration projects to-day.