Search Results

Niche Expansion of an Invasive Predator (Neovison vison), Prey Response, and Facilitative Interactions with Other Invasive Mammals at the Southern End of the Americas: Conservation Challenges and Potential Solutions

Description: The Cape Horn Biosphere Reserve is located at the southern tip of South America. This large archipelago is considered one of the last pristine areas left on the world. Despite it being an unpopulated area with most of the native forest cover intact, it has not been exempt from biological invasions, one of the major drivers of biodiversity loss. Three species that naturally interact in their native range in North America – American beavers (Castor canadensis), muskrats (Ondatra zibethicus), and American mink (Neovison vison) – were independently introduced in this remote region. In my dissertation, I investigated (i) the hypothesis of niche expansion in the invasive mink population on Navarino Island towards terrestrial habitats; (ii) potential mink impact on breeding success of forest-bird populations; (iii) habitat selection of small-rodent species and their perception on the mink's novel predation risk; and (iv) the dynamics of multiple-species invasions under the hypothesis of an invasional meltdown. Additionally, I worked within the framework of environmental philosophy. I provide an example of combining ecological and cultural dimensions within the International Long-Term Ecological Research network to disentangle the ethical dilemmas that surround the management of invasive species. I finally proposed a management plan based on the idea of multiple invasive species management, discussing potential solutions to overcome the challenges that the control of invasive species represent and to more effectively protect the biological integrity of the native ecosystems.
Access: Restricted to UNT Community Members. Login required if off-campus.
Date: December 2017
Creator: Crego, Ramiro Daniel
Partner: UNT Libraries
open access

La Poesía Lírica Colombiana

Description: In this work, superficial to the extreme, it is my purpose to offer a review of the development of lyric poetry ("poesía lírica") in Colombia throughout its history. It is logical that because of the extent of the subject it is not possible to give a complete treatment of our political history, though I have tried not to leave out points of significance. The classification of authors and of poems, as well as the division of periods I have made arbitrarily, guided by my own criteria. Thus, I have the Romantic period divided into romanticism and post-romanticism, according to the dates generally regarded as the beginning and end of these two literary movements. In reality, romanticism only ended with the beginning of modernism, and one cannot therefore distinguish romantic poets from post-romantic poets. Due to the nature of this thesis, many poets--some of them well known--will not be mentioned. However, my intention is not to write a lyric anthology, but to reveal the spirit of Columbia through her poets and her poetry.
Date: August 1952
Creator: Orjuela, Héctor H.
Partner: UNT Libraries
open access

Representative Gaucho Poetry and Fiction of Argentina

Description: This thesis presents a short history and description of the gaucho of Argentina and explores some of the literature that portrays the gaucho way of life.
Date: January 1968
Creator: Sava, Walter
Partner: UNT Libraries
open access

Perón of Argentina: Case Study in Political Charismatic Leadership

Description: The thesis here is that the Argentina of the 1940's provided a perfect matrix for the rise of a charismatic leader. Juan Perón did not emerge as an European-style fascist or the traditional Latin American dictator. Rather, he was called forth by his environment to exercise authority over his followers in a leader-mass, savior-disciple relationship. Perón's base environment was Argentine. Thus, Argentine patterns, values, and culture outlined the scope and methods of his rule. For this reason the total social and political behavior of the Argentine people will be studied and equated with the Perón phenomenon.
Date: August 1967
Creator: Brink, Carol Lynn Robinson
Partner: UNT Libraries
open access

Effects of Macrophyte Functional Diversity on Taxonomic and Functional Diversity and Stability of Tropical Floodplain Fish Assemblages

Description: Multiple dimensions of biodiversity within and across producer and consumer guilds in the food web affect an ecosystem’s functionality and stability. Tropical and subtropical aquatic ecosystems, which are extremely diverse, have received much less attention than terrestrial ecosystems in regards to the effects of biodiversity on ecosystem functioning. We conducted a field experiment that tested for effects of macrophyte functional diversity on diversity and stability of associated fish assemblages in floodplain lakes of the Upper Paraná River floodplain, Brazil. Three levels of macrophyte functional diversity were maintained through time in five floodplain lakes and response variables included various components of fish taxonomic and functional diversity and stability. Components of functional diversity of fish assemblages were quantified using a suite of ecomorphological traits that relate to foraging and habitat use. Response variables primarily distinguished macrophyte treatments from the control. Macrophyte treatments had, on average, double the number of species and total abundance than the control treatment, but only limited effects on stability. The high diversity treatment was essentially nested within the low diversity for assemblage structure and had similar or even slightly lower levels of species richness and abundance in most cases. Gymnotiformes and young-of-year were diverse and relatively abundant in macrophyte treatments contributing to the large differences in diversity between macrophyte and control treatments. Higher fish diversity in structured habitats compared to more homogenous habitats is likely associated with increased ecomorphological diversity to exploit heterogeneous microhabitats and resources provided by the macrophytes.
Date: August 2015
Creator: Treviño, Jessica Marie
Partner: UNT Libraries
open access

The Development of the Sugar, Rubber, and Cotton Industries in Brazil

Description: In this study of the development of the sugar, rubber, and cotton industries in Brazil, the writer proposes to show the development of these industries from the beginning of the industries to about 1947.
Date: 1950
Creator: Miller, James C.
Partner: UNT Libraries
open access

Biodiversity and Genetic Structure of Benthic Macroinvertebrates Along an Altitudinal Gradient: A Comparison of the Windhond and Róbalo River Communities on Navarino Island, Chile

Description: Altitudinal gradients in Sub-Antarctic freshwater systems present unique opportunities to study the effect of distinct environmental gradients on benthic macroinvertebrate community composition and dispersal. This study investigates patterns in biodiversity, dispersal and population genetic structure of benthic macroinvertebrate fauna across an altitudinal gradient between two watersheds on Navarino Island in southern Chile. Patterns in diversity, density, evenness and functional feeding groups were not significantly different across the altitudinal gradient in both the Windhond and Róbalo Rivers. Taxa richness in both rivers generally increased from the headwaters of the river to the mouth, and functional feeding group patterns were consistent with the predictions of the River Continuum Concept. Population genetic structure and gene flow was investigated by sampling the mitochondrial cytochrome oxidase I gene in two invertebrate species with different dispersal strategies. Hyalella simplex (Amphipoda) is an obligate aquatic species, and Meridialaris chiloeense (Ephemeroptera) is an aquatic larvae and a terrestrial winged adult. Contrasting patterns of population genetic structure were observed. Results for Hyalella simplex indicate significant differentiation in genetic structure in the Amphipod populations between watersheds and lower genetic diversity in the Róbalo River samples, which may be a result of instream dispersal barriers. Meridialaris chiloeense exhibited weak population structure but higher genetic diversity, which suggests this species is able to disperse widely as a winged adult.
Date: May 2016
Creator: Pulliam, Lauren
Partner: UNT Libraries
open access

Informing Conservation Management Using Genetic Approaches: Greater Sage-Grouse and Galápagos Short-Eared Owls as Case Studies

Description: Small isolated populations are of particular conservation interest due to their increased extinction risk. This dissertation investigates two small wild bird populations using genetic approaches to inform their conservation. Specifically, one case study investigated a Greater Sage-grouse (Centrocercus urophasianus) population located in northwest Wyoming near Jackson Hole and Grand Teton National Park. Microsatellite data showed that the Jackson sage-grouse population possessed significantly reduced levels of neutral genetic diversity and was isolated from other Wyoming populations. Analysis with single nucleotide polymorphisms (SNPs) and microsatellite data provided further evidence that the population's timing of isolation was relatively recent and most likely due to recent anthropogenic habitat changes. Conservation recommendations include maintaining or increasing the population's current size and reestablishing gene flow with the nearest large population. The second case study investigated the genetic distinctiveness of the Floreana island population of the Galápagos Short-eared Owl (Asio flammeus galapagoensis). Mitochondrial DNA sequence data did not detect differences across nine island populations, yet microsatellite and morphometric data indicated that limited gene flow existed with the population and surrounding island populations, which appeared asymmetric in direction from Floreana to Santa Cruz with no indication of gene flow into Floreana. These results have important conservation implications and recommend that the Floreana Short-eared Owl population be held in captivity during the rodenticide application planned for an ecosystem restoration project in 2018. The population is less likely to receive immigrants from surrounding island populations if negatively effected by feeding on poisoned rodents.
Date: May 2016
Creator: Schulwitz, Sarah E.
Partner: UNT Libraries
open access

The Usage of Clitic Pronouns and the Influence of the Definite Article in Spanish among Spanish-Quechua Bilinguals in Peru

Description: This study focuses on the clitic pronoun usage by Spanish-Quechua bilingual speakers in Cuzco, Peru when faced with a question that includes a definite article preceding the direct object. Answers are analyzed to determine whether or not the definite article has an effect on the presence or absence of the clitic pronoun. Direct objects tested were both [+human] and [-human] objects to determine if these variables affect clitic pronoun use as well. Speakers who have identified themselves as bilingual in both Spanish and Quechua were given a survey to complete in order to see what factors may contribute to the use or omission of the clitic pronouns.
Date: May 2016
Creator: Contreras, Courtney
Partner: UNT Libraries
open access

Modeling State Repression in Argentina and Chile: A Time Series Analysis

Description: This study is an attempt to contribute to the emerging theoretical literature on state repression. A time-series model was developed to test the hypothesis that state violence in Argentina and Chile is largely a function of four internal political factors and their interactions: 1) the inertial influence of past restrictive policies on the formulation of current policies, 2) the annual incidence of political protest demonstrations, 3) the perceived effectiveness of repressive measures on unrest, 4) and the institutionalization of military rule.
Date: December 1993
Creator: King, John Christopher
Partner: UNT Libraries
open access

Nesting Ecology and Reproductive Correlates in the Desert-nesting Gray Gull Larus Modestus

Description: General objectives of my study were to describe the reproductive ecology of gray gulls in the large Lealtad colony, with emphasis on demographic parameters and physiological adaptations of eggs and chicks, which would complete some original objectives established in the early 1980's by Guerra and Fitzpatrick. Specifically, my study focused on describing, then comparing with other desert and non-desert nesting larids, interactive effects of ambient physical conditions and nest-site predation on eggs and chicks.
Date: May 1993
Creator: Aguilar Pulido, Roberto E. (Roberto Eric)
Partner: UNT Libraries
open access

Light Spectra Distributions in Temperate Conifer-Forest Canopy Gaps, Oregon and in Tropical Cloud-Forest Canopy, Venezuela

Description: Light spectra distributions were measured in two different montane forests: temperate and tropical. Spectral light measurements were made in different sized canopy gaps in the conifer forest at H. J. Andrews Experimental Forest in Oregon, USA. Researchers at Oregon State University created these gaps of 20 m, 30 m, and 50 m in diameter. In the tropical cloud forest, spectral light measurements were made in two plots that were permanently established at La Mucuy Parque Nacional in Venezuela, in collaboration with researchers at Universidad de Los Andes. In both studies, spectra and distributions of physiologically active light were analyzed: red, far-red, R/FR ratio, and blue light.
Date: December 1997
Creator: Monteleone, Susan Elaine
Partner: UNT Libraries
open access

Life History Biology of the Desert Nesting Seagull Larus modestus

Description: Gray gulls Larus modestus are unique among birds of northern Chile as the only species nesting in the interior Atacama Desert, and the only seagull nesting far (30 - 100 km) from surface water. During breeding-nesting (August - February) gray gulls congregate on the coast of northern Chile where they feed and initiate courtship. As early as August, breeding pairs commute daily to the inner desert to establish nesting territories, round-trip distances of 60-200 Km. During incubation (30 days) and brooding (7 days) adults alternate daily foraging flights to the coast. Afterwards, both adults forage daily for their chick(s) until fledging (ca. 60 days). Foraging flights and thermoregulatory costs during the period of maximal solar radiation, when ground temperatures may reach 61 C in the day and drop to 2 C at night, have selected for adaptations which minimize those costs: tolerance of hypothermia and hyperthermia; dark plumage; low egg-shell water vapor conductance; low standard metabolic rate; elaborate repertory of thermoregulatory behavior which allow adults to take advantage of microclimatic variations in the desert and minimize costs relative to a sympatric congenor, Larus belcheri scheduling foraging flights to take advantage of optimal atmospheric conditions and presence of forage fish (anchovies) close to the surface; scheduling migration to coincide with anchovy production and levels of interspecific competition; and reduced clutch size ( ≤ 2) relative to most seagulls. Periodic El Nino-Southern Oscillations (ENSO), which reduce principal food items of gray gulls, have selected for 'bet hedging" tactic by which L. modestus either ceases reproduction or varies clutch size between one and two, as observed during and after the 1982-83 ENSO. During a typical reproductive season, breeding pairs allocate a minimum of 39 percent of their net metabolized energy (NME) to foraging flights. Including energy content of eggs, females have an overall …
Date: December 1987
Creator: Guerra Correa, Carlos Guillermo
Partner: UNT Libraries
open access

The Traditional Bambuco in Nineteenth and Twentieth-Century Colombian Composition

Description: Disputes concerning the origin of the term bambuco persist among scholars in Colombia, as well as controversies regarding the process of notating the traditional bambuco (3/4 or 6/8), when it penetrates the written tradition of popular music. Composers writing popular and salon bambucos increasingly perceived the advantage of notating it in 6/8. This study investigates the traditional bambuco and its assimilation into nineteenth and twentieth-century cultivated tradition, with emphasis on piano pieces by representative Colombian composers of art music. I include specific analyses of Cuatro preguntas (ca. 1890) by Pedro Morales Pino (1863-1926), ChirimÍa y bambuco (1930) by Antonio MarÍa Valencia (1902-1952), Bambuco en si menor by Adolf o MejÍa (1905-1970), El bambuco by Manuel MarÍa Párraga (c. 1826-1895), and Trozos Nos. 6 and 158 (1927-1970) by Guillermo Uribe HolguÍn (1880-1971).
Date: August 1993
Creator: Martina, Aileen
Partner: UNT Libraries
open access

Culture Interrupted: Assessing the Effects of the Shining Path Internal Armed Conflict in the Peruvian Highlands

Description: This study was a qualitative examination of social, economic, political, and cultural dilemmas that face Peruvian survivors of the Communist Shining Path Revolution, an internal armed conflict that cut a swath of terror and destruction during the years 1980-2000, with a reported loss of 69,000 residents either killed or considered “disappeared.” The conflict affected primarily poor, uneducated Andean campesinos and townspeople in the highland areas of the Ayacucho District. In this study, I looked closely at the responsibilities of both government and NGOs in the facilitation of readjustment during and after times of instability. In addition, specific challenges the elderly, women and campesinos face in a post-conflict world are analyzed and possible social policies are discerned that might be developed to better implement the transition to a new form of community. Ideas that emerged from this research may assist policy shapers in other less developed countries involved in similar conflicts by examining how Peru dealt with its own issues. Methodology included participant observation and interviews with long-term Ayacuchan residents who stayed-in-place during war time, along with migrants who went to live in shantytowns in more urban areas. The government-mandated Truth and Reconciliation Commission report serves as a framework as it outlined those ultimately deemed responsible and detailed what those affected may expect in the way of appropriate reparations and compensation in the future. Much emphasis is given to the emerging role of women and how ensuing shifts of gender specific cultural roles may affect familial and communal bonds in small-scale societies.
Date: May 2014
Creator: Van Wye, Kalynn Hicks
Partner: UNT Libraries
open access

The Role of Rainfed Farm Ponds in Sustaining Agriculture and Soil Conservation in the Dry High Valley Region of Cochabamba, Bolivia: Design Considerations and Post Impoundment Analysis

Description: Lack of sufficient water for irrigation is a major problem in and around the valleys surrounding the town of Aiquile, Cochabamba Bolivia. In addition, much of the region is undergoing desertification compounded by drought, deforestation, bad traditional agricultural practices, over grazing and a "torrential" rainfall pattern leading to severe soil erosion and low agricultural production. Between 1992 and 1994, the author constructed a network of 24 small, mostly rainfed farm ponds to increase agricultural production and alleviate soil erosion and land-use problems by improving cover conditions. A 5-year post-impoundment analysis was carried out in 1998. The analysis examined current pond conditions, design criteria, irrigation water / crop production increases and the alleviation of land-use problems. Current pond conditions fell into four distinct categories with only 25 percent of the ponds being deemed as "functioning well." The project increased irrigation in the region and improved cover conditions in 66 percent of the pond sites.
Date: August 1999
Creator: Kuiper, John R.
Partner: UNT Libraries
open access

The Impact of U.S. Arms Transfer Policies on Relations with Peru, 1945-1978

Description: This paper examines United States arms transfer policies as they have been applied to Peru since the end of World War II and analyzes the role of these policies in achieving the goals of the United States as delineated by Luigi Einaudi et al. in their Arms Transfers to Latin America: Toward a Policy of Mutual Respect. The paper traces the course of recent U.S.-Peruvian relations, with special emphasis on Peru's arms acquisitions since 1968. The author concludes that, while U.S. arms transfer policies have undoubtedly strained U.S.-Peruvian relations over the past decade, the refusal of the U.S. to provide advanced weapons to Peru will prove to be in the best interests of the United States in the long run.
Date: August 1979
Creator: Davison, J. Les
Partner: UNT Libraries
open access

An Institutional Approach to Economic and Social Patterns of Emulation in Colombia, South America

Description: This study is concerned with the historical development and perpetuation of the leisure class in the Colombian society. The study is based on Thorstein Veblen's Theory of the Leisure Class. The main purpose of this study is to analyze in terms of the evolution of social institutions the problems that the Colombian society faces today. Spanish values and traditions are analyzed, as well as more recent values and modes of behavior adopted by the leisure class. Institutions such as the church, the educational, employment and political apparatus are analyzed in terms of how they contribute to the perpetuation of elites. This study concludes that as long as there is economic surplus in society, a leisure class will exist. The elites forming the leisure class may be displaced by counter-elites, which in turn will conform a new leisure class.
Date: May 1980
Creator: Fernandez, Mauricio, 1955-
Partner: UNT Libraries
open access

Political Factors in the Creation and Implementation of the Andean Foreign Investment Code

Description: The purpose of this investigation is to examine the political factors which came into the creation and implementation of the Andean Foreign Investment Code. This study analyzes the political forces in the creation of the Code and examines the implementation of the Code in each of the Andean countries. This investigation concludes that although the Code has not been implemented uniformly in the Andean countries, it remains an important part of the Andean Common Market. In addition, the continual political consensus among the member countries is emphasized for the continuation of the Andean integration effort.
Date: August 1977
Creator: Gushiken, Anita M.
Partner: UNT Libraries
open access

The Chilean Experience, 1970-1981

Description: The election of a coalition of socialists and communists in 1970 and three years later, the assumption of a military government have led to much controversy around the world. This study attempts to analyze the economic conditions prevailing in Chile from 1970 to 1981. It examines the gradual deterioration of the nation's economy under the Unidad Popular government and the recovery that has taken place with the Junta Militar de Gobierno. The implementation of a market system in 1973 has been effective in bringing the nation out of economic chaos. The balance of payments is under control, inflation has been reduced, and since 1977 the nation's GNP has had an average annual growth of 7.7 per cent.
Date: August 1981
Creator: Mackenna, Leslie R.
Partner: UNT Libraries
open access

The European View of the Incas in the Sixteenth Century

Description: This study seeks to ascertain European views concerning the nature of the indigenous population of Peru by employing contemporary works of Spanish chroniclers. Major focus is on the ideological background of the conquest with elaborations on Iberian philosophies held by conquistadors. Equally important are evaluations of Indian religion and social customs based on such sources as Aristotelian and Thomist doctrines as understood by Spanish writers. Political organization and the hierarchy of rulers play vital roles in determining why the Spaniards overwhelmed the Indians. Conquest destroyed the socio-economic structure of the Inca Empire, and the bonds holding communities together were lost as the Incas accepted Catholicism as their cult.
Date: May 1976
Creator: Greene, Gayle Lee
Partner: UNT Libraries
open access

A Macroeconomic Approach to the Growth of the Bolivian Informal Sector

Description: This thesis attempts to measure the growth of the Bolivian informal sector. The study estimates the growth of the informal sector by defining it as the difference between the formal sector's reported real gross national product (GNP) and forecasted values of real GNP. The first chapter describes the Bolivian economy, defines its informal sector, and presents reasons for this sector's growth. Related research in informal activity, theoretical discussions, and perspectives are presented in the second chapter. Chapter III describes methodological research used in the analysis of the data. Chapter IV describes the results of the investigation. Conclusions and recommendations for the informal sector are provided in chapter V. The results show that it is possible to measure informal activity in a macro setting
Date: August 1989
Creator: Albarracin, Tania
Partner: UNT Libraries
Back to Top of Screen