UNT Libraries - 15 Matching Results
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- Biodiversity and Genetic Structure of Benthic Macroinvertebrates Along an Altitudinal Gradient: A Comparison of the Windhond and Róbalo River Communities on Navarino Island, Chile
- 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.
- The Chilean Experience, 1970-1981
- 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.
- Evolution and the Relationship between Brain and Mind States
- Article discussing the phylogenetic basis of states of consciousness, and presenting the central theses of monism and dualism, in which near-death experiences (NDEs) enjoy very different ontological statuses.
- GEO Year Book 2006: An Overview of Our Changing Environment
- This publication describes major global environmental issues and policy decisions during 2006.
- GEO Year Book 2007: An Overview of Our Changing Environment
- This publication is an overview of major global environmental issues and policy decisions during the course of 2007.
- Global Trends in Sustainable Energy Investment 2010: Analysis of Trends and Issues in the Finacning
- This report shows that in spite of the global economic downturn, investment in sustainable energy is still strong.
- Life History Biology of the Desert Nesting Seagull Larus modestus
- 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 …
- Modeling State Repression in Argentina and Chile: A Time Series Analysis
- 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.
- Nesting Ecology and Reproductive Correlates in the Desert-nesting Gray Gull Larus Modestus
- 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.
- A Neurobiological Model for Near-Death Experiences
- Article presenting a neurobiological model for near-death experiences (NDEs) in an attempt to correlate the biological and psychological domains. This model is based on temporal lobe dysfunction, hypoxia/ischemia, stress, and neuropeptide/neurotransmitter imbalance.
- A Neurobiological Model for Near-Death Experiences. [Part] 2: The Problem of Recall of Real Events
- Article proposing a scientific approach to explain the fact that some near-death experiencers (NDErs) are able to recollect and verbalize real events occurring in the environment during the experience.
- 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
- 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.
- Political Factors in the Creation and Implementation of the Andean Foreign Investment Code
- 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.
- Response to Commentaries on "A Neurobiological Model for Near-Death Experiences"
- Article responding to critiques of an article written by the authors, entitled "A Neurobiological Model for Near-Death Experiences."
- Salvador Allende: the Rise and Fall of a Chilean Marxist
- This study is concerned with describing and analyzing the factors that led to the election and subsequent defeat of Salvador Allende. The research information was selected from leading books, periodicals, government documents, archives, and newspapers. The thesis presents the political history of Allende's rise to power, the social structure that made his victory possible, the development of major programs that facilitated his ascension and that made his decision inevitable, and, finally, an analysis of his administration with observations as to why he failed. The importance of the lower class, the middle class, the military, and the United States are presented as factors contributing to Allende's victory and later accelerating Allende's fall from power.