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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.
191

First Record of Procyon Cancrivorus (G. Cuvier, 1798) (Carnivora, Procyonidae) in Stratigraphic Context in the Late Pleistocene of Brazil

Rodriguez, Sergio G., Soibelzon, Leopoldo H., Rodrigues, Shirlley, Morgan, Cecilia C., Bernardes, Camila, Avilla, Leonardo, Lynch, Eric 01 August 2013 (has links)
Although five genera of procyonids are currently present in South America, only two of the extant genera, Procyon and Nasua are represented in the South American fossil record. A recent discovery of a procyonid lower second molar in Late Pleistocene deposits of Aurora do Tocantins, northern Brazil, offers potential to further our understanding of the stratigraphic and temporal range of South American fossil procyonids. We use geometric morphometric analysis of two-dimensional landmarks and semilandmarks to explore morphological variation in the lower second molars of extant Procyon lotor and Procyon cancrivorus and multivariate methods to support the identification of the Pleistocene specimen as P. cancrivorus. This material represents the second fossil record of P. cancrivorus in South America Procyonids entered South America in two phases: the first comprising by Cyonasua and Chapadmalania during the Late Miocene, and the other recent genera, beginning in the Late Pleistocene. These Late Miocene procyonids were more carnivorous than Late Pleistocene-Recent omnivorous taxa and possible went extinct due to competition with other placental carnivorans that entered South America and diversified during the latest Pliocene-Early Pleistocene.
192

Polygenic prediction and GWAS of depression, PTSD, and suicidal ideation/self-harm in a Peruvian cohort

Shen, Hanyang, Gelaye, Bizu, Huang, Hailiang, Rondon, Marta B., Sanchez, Sixto, Duncan, Laramie E. 01 January 2020 (has links)
Genome-wide approaches including polygenic risk scores (PRSs) are now widely used in medical research; however, few studies have been conducted in low- and middle-income countries (LMICs), especially in South America. This study was designed to test the transferability of psychiatric PRSs to individuals with different ancestral and cultural backgrounds and to provide genome-wide association study (GWAS) results for psychiatric outcomes in this sample. The PrOMIS cohort (N = 3308) was recruited from prenatal care clinics at the Instituto Nacional Materno Perinatal (INMP) in Lima, Peru. Three major psychiatric outcomes (depression, PTSD, and suicidal ideation and/or self-harm) were scored by interviewers using valid Spanish questionnaires. Illumina Multi-Ethnic Global chip was used for genotyping. Standard procedures for PRSs and GWAS were used along with extra steps to rule out confounding due to ancestry. Depression PRSs significantly predicted depression, PTSD, and suicidal ideation/self-harm and explained up to 0.6% of phenotypic variation (minimum p = 3.9 × 10−6). The associations were robust to sensitivity analyses using more homogeneous subgroups of participants and alternative choices of principal components. Successful polygenic prediction of three psychiatric phenotypes in this Peruvian cohort suggests that genetic influences on depression, PTSD, and suicidal ideation/self-harm are at least partially shared across global populations. These PRS and GWAS results from this large Peruvian cohort advance genetic research (and the potential for improved treatments) for diverse global populations. / National Institutes of Health / Revisión por pares
193

Investigating Characteristics of Lightning-Induced Transient Luminous Events Over South America

Bailey, Matthew A 01 May 2010 (has links)
Sprites, halos, and elves are members of a family of short-lived, luminous phenomena known as Transient Luminous Events (TLEs), which occur in the middle atmosphere. Sprites are vertical glows occurring at altitudes typically ranging from ~40 to 90 km. In video imagery they exhibit a red color at their top, with blue tendril-like structure at low altitudes. Elves are disk-like glows that occur at the base of the ionosphere, with diameters of ~100-300 km, and have very short lifetimes (~2-3 ms). Halos are diffuse glows that occur at low altitudes, have diameters <100 >km, and have a duration that may last up to 10s of ms. A majority of the studies of TLEs have taken place over the Midwestern U.S. where they were first discovered. This area produces large thunderstorms, which in turn generate large lightning discharges that have been associated with the formation of TLEs. Studies have used the low frequency radiation that initiates with these strokes to study characteristics of these events. This low frequency radiation has been used to determine where large numbers of TLEs may occur. Extreme southern Brazil is a region of the globe believed to have many TLEs, but few studies on these phenomena. Two collaborative campaigns involving Utah State University proceeded in 2002- 2003, and in 2006. Multiple TLE images were made, proving this is, indeed, a region of the globe where these types of events are prominent. In particular, one storm in February 2003 produced over 440 TLEs imaged by USU video cameras. Of these events, over 100 of them had associated halos. Statistical studies for halos previously had been performed in the U.S., but never abroad. Also, several events from the February storm have been associated with negative cloud to ground lightning, a surprising occurrence, as to date, less than a handful of such events have ever been witnessed or published. In analyzing the TLEs from this campaign, we have shown the halos are similar to those seen in the U.S., even though the storms may be somewhat different. Also, detailed analyses of the negative events show both temporal and spatial morphology heretofore never reported on.
194

A 4600-year record of lake level and hydroclimate variability from an eastern Andean lake in Colombia

Rudloff, Owen M. 05 1900 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Hydroclimatic variability in the eastern Colombian Andes is examined using a decadally-resolved, multiproxy lake sediment record from Laguna de Ubaque, Colombia. Hydroclimate trends are examined and compared to existing local, regional, and trans-Andean records to enhance existing knowledge of Late Holocene Colombian precipitation and assess potential hydroclimatic forcing mechanisms in tropical South America. Sedimentological analyses, including percent lithics, grain size, C:N and magnetic susceptibility are sensitive to hydroclimate and lake level while charcoal size and concentrations reflect fire variability. Results show that deep lacustrine conditions characterized by laminated deposits were not established until approximately 3500 cal yr B.P., prior to which, terrestrial C:N values and unstructured sediments indicate that drier, marsh-like conditions prevailed. Between 3500 and 2000 cal yr B.P., interrupted only by a 300-year arid interval from 2800 to 2500 cal yr B.P., greatly increased overall clastic deposition indicates a broad precipitation maximum while decreased sand deposition and the preservation of finely laminated sediment indicate deep lake conditions. After 2000 cal yr B.P., decreased clastic deposition suggests reduced precipitation, but the continued accumulation of laminated sediments indicates that conditions were wet enough to fill the basin continuously until the present day. These observations address two of the driving questions of Andean paleoclimate: were the northern and southern Andes in vi phase during the Holocene, or out of phase, and what are the main drivers of Holocene Andean climate? We find that the early part of Ubaque’s record more closely resembles southern Andean precipitation records until 2000 cal yr B.P., at which point it abruptly switches to resemble northern precipitation records. We attribute this to a combination of the southward migration of the intertropical convergence zone (ITCZ), and an increase in eastern Pacific sea surface temperatures (SST). In addition, we find that Colombian hydroclimate records exhibit a bimodal precipitation pattern, which we attribute to their location either on the Andean slopes or in the high interior Andes.
195

Body Image in Adolescents from Urban Communities in Ecuador

Phillips, Claire E. January 2018 (has links)
No description available.
196

Genomic and Climatic Effects on Human Crania from South America: A Comparative Microevolutionary Approach

Herrera, Brianne 04 September 2019 (has links)
No description available.
197

PUBLIC, PRIVATE, PAST, AND PRESENT: AN EXPLORATION OF THE LANGUAGE AND MUSICAL STRUCTURES OF KOTIRIA/WANANO WOMEN’S KAYA BASA ‘SAD SONGS’

Hosemann, Aimee Jean 01 May 2017 (has links) (PDF)
This dissertation explores the way Kotiria/Wanano (E. Tukanoan, Kotiria hereafter) women of the Brazilian Alto Rio Negro (ARN) contrive (McDowell 1990) kaya basa ‘sad songs’ using linguistic and musical resources to construct songs that express loneliness and other private emotions, while also creating alliances and separations from other women in their lives. A central concept is the practice of linguistic exogamy, in which Kotiria marry speakers of other languages, creating a multilingual and multivocal, cacophonic sound during po’oa exchange ceremonies. I compare these songs to mythological narratives depicting the beginnings of Kotiria society and the roles of men and women within it, as well as men’s ceremonial forms of speech and unmarried women’s joking songs as a way to think about the resonances of sound and meaning married women create in their songs. Drawing on resources from linguistic anthropology, ethnomusicology, semiotics, and intersectional feminism, I demonstrate that the singing of – and listening to – kaya basa is a fundamental social structuring event. Despite previous works (e.g., Brüzzi 1962) that saw men’s expressive practices like shamanic chanting or ritual instrument playing as those upholding the social order, I argue that the social order owes its stability equally to women’s public participation in musical practice. Following Hill’s formulation of musicalizing the other (1993, 2009, 2011, 2013), I demonstrate that kaya basa reflect on inter- and intra-community relations on the macro level, while also giving women the chance to comment on important life transitions on the micro level. Moreover, my combined linguistic and spectrographic analyses of the sounds of these songs illustrate the intricate relations between the sounds of language and the sounds of music, the methods by which one understands something is true or false, and how individual singers can contrive differently within the same genre to create a well-formed song. I propose further work on this genre, and on genres that seem to be related which are produced by other groups in the area. I extend Beier, Michael, and Sherzer’s (2002) conception of the greater Amazonian discourse area to one of a greater Amazonian soundscape in which sonic ways of producing and gathering meaning (acoustemologies, Feld 1996) have been and are a major driving force in the arraying of social life across language families in the ARN.
198

Ecology and Conservation of Bird Assemblages in Native and Afforested Environments in the Northern Campos Grasslands of Uruguay

Martínez Lanfranco, Juan Andrés 08 December 2017 (has links)
Commercial forestry has expanded across the Rio de la Plata Grasslands (RPG) of South America in recent decades. I conducted a resource-use based study on bird communities during the 2013-2014 austral breeding season in northern Uruguay. I assessed relationships between habitat types and bird abundance as a function of vegetation structure. To compare avian responses to treatments, I included native environments, pine and eucalyptus plantations of different ages and thinning regimes. I detected differences in species richness and composition and species-specific responses in abundance along structural gradients sampled. Although poorer in species than native habitat types, tree plantations were extensively used by birds. Birds associated with plantations were primarily habitat generalists and forest dependent species, with low incidence of grassland specialists. Results of my study provide baseline information for stand-level management and future landscape design of timber plantations to benefit conservation of bird communities in afforested landscapes in the RPG.
199

A Speleothem-Based High Resolution Reconstruction of Climate in Southeastern Brazil Over the Past 4,100 Years

Taylor, Brandon L 01 January 2010 (has links) (PDF)
Isotopic investigations of speleothem CR1 from Cristal Cave in southeastern Brazil have established a high-resolution record of climate change extending 4,100 years prior to sample collection in 2007. A total of 14 subsamples were collected from CR1 for U/Th age determination. ICP-MS analysis yielded very precise ages with analytical errors (2σ) averaging ± 13 years. An initial growth rate of .062 mm y-1 for the first 2860 years is followed by a rate of .08 mm y-1 for the remaining growth period allowing for sampling of δ18O at sub-decadal resolution. Stable isotope analyses show a large range of δ18O values between -7.5 ‰ to -4 ‰. The data show a trend of steadily decreasing values over the past 4,000 y BP. The exception to this trend is the last 150 years BP when some of the least negative and most variable values for the record are observed. Variations in speleothem δ18O in southern Brazil have been shown to reflect changes in rainfall δ18O, which in turn indicate changes in rainfall source or rainfall amount (Cruz et al., 2006). In Southeastern Brazil, δ18O is controlled mainly by moisture source location, in particular South American monsoonal versus extratropical sources (Cruz et al., 2005). The relative contribution of monsoonal and extratropical moisture help to define the δ18O of regional precipitation via the mean location and southward extent of Hadley cell convective activity associated with the South American summer monsoon (Cruz et al., 2005). For example, decreases in precipitation δ18O are often interpreted as a decreased contribution of winter versus summer precipitation (Cruz et al., 2005). Assuming that the modern (observed) relationship between the seasonality and moisture source location effect occurring in southeastern Brazil have functioned for the past ~ 4,100 years, trends of more negative values towards modern day are likely due to increased summer precipitation and/or an overall increase in total yearly precipitation. The more enriched values of the past 100 years suggest a recent decrease in summer and/or total rainfall.
200

Informal - Informal architecture of South and Central America

Hansson, Andrea Jean January 2023 (has links)
This thesis aims to address the topic of informal vernacular architecture in a focal group of chosen villages in South and Central America. With the goal to represent their informal architecture and its connection to identity, culture, and sustainability. What I’m referring to as informal architecture in this thesis, is something referred to by many names in the contemporary vocabularies. Many of them has been used through a derogatory undertone. Therefore, the prime setting that I want to underline is that this investigation is not to depreciate the informal architecture, in any kind of way. This is an investigation that aims to go deeper through what I hold in high regards – an informal language of architecture that generates another type of value than other languages of architecture do.  It’s an investigation through the tectonic system that defines the private, and the generated voids that holds space for the collected public life of the communities. How the culture, the life, the holistic beliefs, and the condition of the site is reflected on the tectonic structure and architectural expression.  My goal with this work is to not only give my analysis but also to generate an analysis with the viewer through expressing the different villages in a comparative language. Why? Because I want to share a fraction of the knowledge that the people of these villages gave to me.

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