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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
141

Cranial Variability in Amazonian Marmosets

Aguiar, John Marshall 2009 December 1900 (has links)
The family Callitrichidae encompasses the marmosets and tamarins, the smallest of the anthropoid primates and one of the most species-rich of platyrrhine families. Seven new species of Amazonian marmosets (Callithrix, Callitrichidae) have been discovered in recent years, as well as the exceptional dwarf marmoset Callibella humilis. Most of these species were described on the basis of their pelage and presumed separation by major rivers. I performed analyses of craniometric variables by taxa and by river basins, in order to determine if there are significant cranial distinctions between taxa separated by rivers. I analyzed quantitative cranial and mandibular characters of Callibella humilis to determine if it could be distinguished from other callitrichids. I found that Callibella is clearly distinct from all other genera of marmosets and tamarins, in particular in the morphology of the lower jaw. I also analyzed representative species of Amazonian Callithrix and found support for the theory of separation by river-barriers. In my analyses the Amazonian marmosets were divided into three separate species groups, with the easternmost species (Callithrix argentata and C. leucippe) strongly distinct and separated from the others by the broad Rio Tapajos. Two additional species, C. chrysoleuca and C. saterei, formed a discrete group in the central Amazon, and the westernmost species - C. melanura, C. nigriceps and the Rondonia marmoset - formed a third distinct group. These results from cranial morphology align with recent genetic studies indicating that the Amazonian marmosets are strongly divided by the Rio Tapajos, and offer additional support to the theory of river-barriers. Although these species are typically considered to be of low conservation priority, many of them are found in areas experiencing accelerated deforestation. An initial analysis of protected-area coverage for the Amazonian marmosets demonstrates that while some species may be found in a number of protected areas, others are virtually uncovered, and the lack of comprehensive information on their distributions may preclude an effective conservation strategy. The dwarf marmoset Callibella is known from an exceptionally restricted range, with almost no protected areas, and this unique species should be a conservation priority.
142

Smallholder livelihoods and market accessibility in the Peruvian Amazon

Cardozo, Mario Luis 26 July 2013 (has links)
Abstract: This study examines how differential accessibility to regional markets and natural resources affects smallholder livelihoods in the northeastern Peruvian Amazon, particularly in terms of household income diversification or specialization. A combination of qualitative and quantitative methods were applied to semi-structured smallholder household (N = 319) and community leader interview data collected in 40 communities in 2006-2007, in addition to change detection performed on Landsat satellite imagery (1987, 1993, and 2001). First, the dissertation explores changes in smallholder land use patterns across the study region during a period of profound macroeconomic changes and continual urbanization, finding that overall land use trends of agricultural abandonment reflected national reductions in agrarian subsidies. Second, based on interview data, household processes of income diversification and specialization were analyzed in two sections of the study area, the Itaya and Nanay basins. In the Itaya Basin, it was observed that smallholder livelihood specialization was aided by road development increasing transportation accessibility to important regional markets. In the more isolated Nanay Basin, livelihood choices were found to be influenced by processes of livelihood displacement caused by conservation efforts, in addition to remoteness and river seasonality. This study concludes by reflecting on the importance of the spatial relations of access to resources and markets in the region and in similar places in the developing tropics. This kind of information can help make national and regional policy decisions on such issues such as conservation, agrarian credits, road development, which may differentially affect smallholder livelihoods and their environments. / text
143

Catweetegories : machine learning to organize your Twitter stream

Simoes, Christopher Francis 14 April 2014 (has links)
We want to create a web service that will help users better organize the flood of tweets they receive every day by using machine learning. This was done by experimenting with ways to manually classify training sets of tweets such as using Amazon’s Mechanical Turk and crawling the Internet for large quantities of tweets. Once we acquired good training data, we began building a classifier. We tried NLTK and Stanford NLP as libraries for creating a classifier, and we ultimately created a classifier that is 87.5% accurate. We then built a web service to expose this classifier and to allow any user on the Internet to organize their tweets. We built our web service by using many open source tools, and we discuss how we integrated these tools to create a production quality web service. We run our web service in the Amazon cloud, and we review the costs associated with running in Amazon. Finally we review the lessons we learned and share our thoughts on further work we would like to do in the future. / text
144

Payments for ecosystem services : opportunities and challenges in the Brazilian Amazon

Marquez, Mayra 16 March 2015 (has links)
Brazil has committed to reducing deforestation in the Amazon and has identified target goals for 2020. A variety of environmental policies and tools are used to reduce deforestation in the region, including payments for ecosystems services (PES). This report analyzes whether payments for ecosystem services are a viable option for supporting conservation and socio-economic goals in the Amazon. PES schemes provide economic incentives in exchange for meeting an environmental goal. They have been relatively successful in developed countries but have had limited applications or success in developing contexts. This report identifies the agents and activities that drive deforestation in the Brazilian Amazon and determines which of these may be suitable for PES applications. It also provides a framework for analyzing current PES schemes in order to draw out best practices and lessons learned which may be applied to future program. PES schemes do have a role to play as one of the tools used in addressing deforestation in the Amazon. They can be cheaper than indirect approaches but do face some challenges in evaluation. Future PES applications may benefit from the lessons learned in the early applications of these programs. / text
145

Challenging the turnover hypothesis of Amazon deforestation : evidence from colonization projects in Brazil

Campari, Joao Santo 10 May 2011 (has links)
Not available / text
146

Land Surface Processes In Natural and Artificial Tropical Ecosystems

Rosolem, Rafael January 2010 (has links)
Land Surface Parameterization (LSP) schemes have evolved from simple tipping-bucket models to fully interactive models, including parameterizations which account for exchanges of momentum, energy, mass, and biogeochemistry. As the demand for greater realism has increased, so has the complexity of LSPs which now includes some parameters that may not be universally relevant to all regions of the globe. The performance of LSP schemes depends on the magnitude of structural, data-related (input and output), and parameter uncertainties in the model. Parameter estimation uncertainty can be reduced by calibrating LSPs against measurements available at field sites. Given the multiple outputs of the models, multi-objective optimization approaches are performed. Some of the parameter values used in LSPs have originally obtained from laboratory studies which analyzed plant behavior under a range of conditions in enclosed chambers. The research described in this dissertation takes advantage of currently available data from several eddy covariance flux towers located mainly in the Brazilian Amazon basin to estimate parameter values of a widely-used LSP scheme, version 3 of the Simple Biosphere model (SiB3). Background climatological data was used to assess the representativeness of the data collection period that might have affected model calibration. Variance-based sensitivity analysis was then used to investigate potential structural deficiencies in SiB3 and to reduce the dimensionality of the subsequent optimization by identifying those model parameters that merit calibration. Finally, some structural and conceptual aspects of SiB3 were tested inside Biosphere 2 Tropical Rain Forest biome (B2-TRF) under meteorological conditions that resemble those predicted in future climate scenarios for the Amazon basin.
147

"Take a Picture with a Real Indian": (Self-) Representation, Ecotourism, and Indigeneity in Amazonia

Temarantz, Ami 11 August 2011 (has links)
This thesis uses three case studies to analyze and contextualize the interface between Western conceptions of indigenous peoples and nature and community-based conservation and development schemes in the Amazon: Kapawi Ecolodge (Ecuador), Chalalán Ecolodge (Bolivia), and Posada Amazonas (Peru). It explores how three Amazonian communities represent their indigenous identity in the online marketing of their ecotourism lodges. As a methodological tool, this research identifies four characteristics of the Ecologically Noble Savage stereotype: the spatial, the spiritual, the temporal, and the cultural. Current ethnographic literature describing these communities is used to analyze these self-representations. This thesis examines these representations within larger academic discussions on authenticity, power and control, and the long-term viability of ecotourism as a community-based development model.
148

Global Governance in the Brazilian Amazon : Co-Management of Land Resources

Mancheva, Irina January 2010 (has links)
The aim of this paper is to critically asses the different actors participating in the multilevel management of land resources in the Brazilian Amazon, through the theoretical framework of global governance studies and resource co-management. Four principles of adaptive resource co-management from existing theory were used: co-management as power sharing, comanagement as institution building, co-management as good governance, and co-management as trust building. During the analysis of the empirical material it became apparent that one side of the interaction between different actors in the Brazilian Amazon was not covered in previous literature, and that was the formation of horizontal and/or vertical partnerships between independent entities, or “co-management as network creation”. These partnerships, lasting or not, are established for the achievement of the common aim and lead to gains for all parties involved.
149

Lead exposure in indigenous children of the Peruvian Amazon : seeking the hidden source,venturing into participatory research

Anticona Huaynate, Cynthia January 2012 (has links)
Introduction. In 2006, a Peruvian environmental agency reported the presence of elevated blood lead levels (BLLs) in indigenous communities of the Corrientes river basin. This is a territory in the Peruvian Amazon where oil activity has been associated with serious environmental effects, with impact on an ongoing social conflict. This PhD project aimed to determine the lead sources, risk factors and pathways in children of these communities and to suggest control and prevention strategies. Given the arguments attributing the lead source to the oil activity pollution, the second objective was to clarify any potential connection between the two. This project was conducted by a collaborative research partnership with the regional health authorities and the community-based organization. The third objective was to characterize the challenges, facilitating factors and the lessons learned from the research process. Methods. Two epidemiological studies were conducted. Study I (2009) was carried out in three communities and study II (2010) in six communities with different levels of exposure to oil activity. The participants were children 0–17 years old. Data collection included: determination of BLLs, hemoglobin levels and anthropometric indicators, a risk factor questionnaire, an environmental assessment and a risk map. Data analysis included univariate, bivariate and multivariate logistic regression. Data for the third objective came from field notes, documents, interviews and a process of collective reflection. Results. Study I (n= 221) found no significant difference in the geometric mean(GM) BLLs between the communities exposed and not exposed to oil activity. Older age and being a boy were found as risk factors for BLLs ≥ 10 μg/dL. In study II (n= 346), age stratified logistic regression models indicated that children 0–3 years whose mothers had BLLs ≥ 10 μg/dL, children 0–6 years who played with pieces of lead and children 7–17 years who fished 3 times or more per weekor chewed pieces of lead to manufacture fishing sinkers had a significant increased risk of having BLLs ≥ 10 μg/dL. Children who lived in communities near oil battery facilities also had a significant increased risk of having BLLs ≥ 10 μg/dL. In both studies, environmental samples showed lead concentrations below reference levels. The challenges and facilitating factors identified focused on five interrelated themes: i) mutual trust, ii) multiple agendas, iii) equal participation, iv) competing research paradigms and v) complex and unexpected findings. Conclusions. Metal lead appeared to be the main source of exposure. Playing with pieces of lead and chewing pieces of lead to construct fishing sinkers appeared to be pathways of exposure for children aged 0–6 years and 7–17 years, respectively. Mothers’ BLLs > 10 μg/dL was a risk factor for BLLs > 10 μg/dL in children aged 0–3 years. Living in a community with high exposure to oil activity was a risk factor for BLLs > 10 μg/dL. The identified connection with oil activity was the proximity of communities to oil battery facilities and thus greater access to lead from cables and other industrial waste. Despite the numerous challenges, participatory research appears to be the most appropriate approach for this type of context. The study findings led us to recommend:i) a comprehensive community-based lead control and prevention plan,ii) the introduction of substitute non-harmful material(s) for fishing sinkers and iii) secure containment of the oil company’s waste deposits. / Introducción. En el 2006, una agencia ambiental del Perú informó de la presenciade niveles elevados de plomo sanguíneo en las comunidades indígenas dela cuenca del río Corrientes. Este es un territorio en la Amazonía peruana, dondela actividad petrolera ha sido asociada con graves efectos ambientales, originandoun continuo conflicto social.Este proyecto de tesis doctoral tuvo como objetivo determinar las fuentes, factoresde riesgo y vías de exposición de plomo en niños de estas comunidades paraproponer estrategias de control y prevención. Teniendo en cuenta previos argumentosque relacionaban la exposición de plomo con la contaminación por laactividad petrolera, el segundo objetivo fue esclarecer cualquier conexión entreambos. Este proyecto se condujo con la participación de miembros de la DirecciónRegional de Salud de Loreto (DIRESA Loreto) y de la organización indígenaFECONACO. El tercer objetivo fue caracterizar los desafíos, las oportunidades ylos aprendizajes del proceso participativo.Métodos. Se condujeron dos estudios epidemiológicos. El estudio I (2009) sedesarrolló en tres comunidades y el estudio II (2010) en seis comunidades condiferentes niveles de exposición a la actividad petrolera. Los participantesfueron niños de 0–17 años. La recolección de datos incluyó: determinación deplomo sanguíneo, de niveles de hemoglobina y de indicadores antropométricos,un cuestionario de factores de riesgo, una evaluación ambiental y un mapa deriesgo. El análisis de datos incluyó análisis univariado, bivariado y multivariadode regresión logística. Para el tercer objetivo, los datos provinieron de notas decampo, documentos oficiales, entrevistas informales y un proceso de reflexióncolectiva.Resultados. En el estudio I (n = 221) no se encontró diferencia estadísticamentesignificativa entre las medias geométricas de los niveles de plomo sanguíneo delas comunidades expuestas y no expuestas a la actividad petrolera. Los niños degénero masculino y los del grupo etario de mayor edad tuvieron un riesgo significativamentemayor a presentar niveles de plomo sanguíneo > 10 μg/dL. Enel estudio II (n = 346), los modelos estratificados por edad indicaron que losniños de 0–3 años cuyas madres tenían niveles de plomo > 10 μg/dL, los niñosde 0–6 años que jugaban con piezas de plomo y los niños de 7–17 años que pescaban3 veces o más por semana o masticaban piezas de plomo para fabricarpesas de pescar tenían un riesgo significativamente mayor de presentar nivelesde plomo sanguíneo > 10 μg/dL. Los niños que vivían en comunidades cercanasa las baterías de petróleo también tuvieron un riesgo significativamente mayora presentar plomo sanguíneo > 10 μg/dL. Las muestras ambientales en ambosestudios mostraron concentraciones de plomo por debajo de los niveles de referencia.En cuanto al proceso de investigación, los desafíos y oportunidades másimportantes se centraron en cinco temas interrelacionados: i) la confianza mutua,ii) múltiples agendas, iii) participación equitativa, iv) competencia de paradigmasen la investigación y v) diseminación de resultados complejos e inesperados.Conclusiones. La fuente de exposición principal sería el plomo metálico. Jugarcon piezas de piezas de plomo y masticar piezas de plomo para la construcciónde pesas de pescar serían vías de exposición para los niños de 0–6 años y 7–17años, respectivamente. Niveles de plomo sanguíneo > 10 μg/dL en las madressería un factor de riesgo para presentar niveles de plomo sanguíneo > 10 μg/dLen niños de 0–3 años. Vivir en una comunidad con alta exposición a la actividadpetrolera sería también un factor de riesgo para presentar niveles de plomo sanguíneo> 10 μg/dL. La conexión con la actividad petrolera parece estar en laproximidad de las comunidades a las baterías del petróleo y por ende, el mayoracceso al plomo proveniente de cables y otros residuos industriales.A pesar de los varios desafíos, la investigación participativa parece ser el enfoquemás apropiado para este tipo de contextos. Los hallazgos nos llevaron a recomendar:i) un programa comunitario de control y prevención de plomo, ii) laintroducción de pesas de pescar de materiales seguros, alternativos al plomo yiii) el control de la disposición de residuos de la actividad petrolera.
150

Labor access and unequal land holdings among peasant farmers in a lowland and upland community of the Peruvian Amazon

Brisson, Stéphanie January 2003 (has links)
Researchers recognize the need to better understand the factors influencing indigenous land use in order to design sustainable tropical forest management programs. A key relationship that has been long overlooked in peasant societies is the one between communal labor access through social networks and land acquisition/accumulation. This study examines land distribution and labor patterns in traditional agriculture of a lowland and a upland community on the Maranon River near Iquitos, Peru. Data were gathered through household interviews (n=76) and field visits (n=396) between June and November 2001. Results reveal marked variations in access to land and communal labor between and within communities. Household age, initial land wealth and initial inputs of labor are crucial in explaining land and labor inequalities within villages. This research contributes to a better understanding of the factors that give rise to local heterogeneity in wealth holdings and livelihood strategies, necessary tools to promote conservation throughout the region and beyond.

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