Thesis (Ph. D.)--University of Chicago, Dept. of History, March 1997. / Includes bibliographical references. Also available on the Internet.

Thesis (Ph. D.)--Ohio State University, 1972. / Includes vita. Includes bibliographical references (leaves 322-332). Available online via OhioLINK's ETD Center.

No description available.

Our objective was to identify the major barriers to natural regeneration of tree species in abandoned Panamanian pastures as a first step in formulating management strategies to facilitate forest recovery. We tested whether fire, seed dispersal, and the presence of an introduced grass, Saccharum spontaneum L., were barriers to forest regeneration. We examined growth, survival, and density of both experimentally-introduced and naturally-regenerating tree seedlings using a series of multifactorial experiments. / We found that seed dispersal limits forest regeneration. Large-seeded species have the highest performance in the Saccharum spontaneum, but were found in the lowest abundance in natural conditions. Small-seeded species were most frequently observed, but they have the lowest survival. We conclude that dispersal limitations preclude entry of the larger-seeded species. Distance from the forest limits dispersal of many small-seeded species. Fire is a major barrier to natural regeneration because it lowers species diversity.

Thesis (Ph. D.)--University of Arkansas, Fayetteville, 1998. / "May 1998." eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 221-225).

This thesis investigates the possibility of using aposematic insects as guides to plants that contain pharmacologically-active compounds. Plants were monitored within national parks in the Republic of Panama over a period of six months and all insects feeding on them were collected and raised in captivity. The insects were then extracted and analyzed to determine how they were treating toxic chemical compounds in their host plant. Two principal plants were investigated with their associated insects: (1) Vismia baccifera and (2) Mikania guaco. One generalist and one specialist Lepidopteran species were found to sequester vismione B from their host plant Vismia baccifera, a cytotoxic compound active against three cancer cell lines. Two specialist Coleopterans were found to sequester the novel compound Guacanone, isolated by the primary author from the vine Mikania guaco and active against Trypanosoma cruzi, the causative agent of Chagas' disease. A generalist Coleopteran was found to not sequester this compound. (Abstract shortened by UMI.)

This thesis investigates five types of informal and self-built settlements in Panama City, Panama. The major part of the thesis focuses on precedents that are related to personal experiences encountered while researching a question developed during an independent study course at Ball State University. These experiences are germane to the place I have resided for virtually, my whole life, at the outskirts of an informal settlement in Panama City -- Barriada Nueve de Enero -- along with my personal relationship with Mrs. Emilia, my family's domestic worker for more than thirteen years. In addition, the study of the five settlements will be accompanied by a set of minor design interventions that address immediate and local needs encountered while investigating each area. In a country where already more than half the population (56%) resides in urban centers, and approximately sixty thousand people live in informal settlements, one might ask: What do rural immigrants bring with them to the informal settlements? And, what are the connections found that relate to their past lives in the rural areas? According to the UN-Habitat report of 2008, in the developing world there are approximately 5 million people making thier trek each month to urban centers, and most of them end up squatting and self-building in some informal settlement, making them, as stated by Robert Neuwirth in Shadow Cities, "the largest builders of the housing world." If it is in fact, the 'precaristas - informal builders' and 'invasores - inavders' of the world who are shaping our current and future cities, should we not be more interested in their knowledge, lifestyles, and building techniques? This thesis does not aim to answer all the questions about informal settlements in Panama, but it does try to expose a reality and hopefully generate an understanding towards one city, and at least one informal settler contributing to the fast-growing informal building phenonmenon of the world. / Department of Architecture

No description available.

No description available.

Thesis (M.A.)--University of North Carolina at Wilmington, 2006. / Includes bibliographical references (p. [89]-95)