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Isotopic evidence of Bronze Age diet and subsistence practices in the southeastern Carpathian Bend area, RomaniaAguraiuja, Ülle January 2017 (has links)
Human and faunal osteological material from the southeastern Carpathian Bend area, Romania, was analysed for δ13C, δ15N and δ34S to reconstruct the dietary practices of the Middle Bronze Age Monteoru culture. As a secondary objective, the extent of intraskeletal variation in stable isotope values was investigated by comparing skeletal elements with differing collagen turnover rates. The intraskeletal isotope results revealed a pattern where cortical bone samples produced statistically lower δ13C values compared to trabecular bone samples, highlighting the necessity for more systematic research to understand how stable isotopes are incorporated into bone collagen of various skeletal elements. Diet in the Monteoru culture was shown to be exclusively or predominantly terrestrial in origin with no detectable input of C4 or marine resources. Differences in average δ13C and δ15N values between the two sites included in the study (representing distinct phases of the culture) suggest a shift in dietary preferences from a more meat-based economy to a more dairy- and plant-based economy. The dissimilar contribution of animal foods to overall diet between the two sites was supported by estimates generated by the Bayesian mixing model FRUITS, which also showed that in both sites plant foods accounted for most of the calories consumed. The faunal isotopic data contained a few outliers, suggestive of deliberate movement of livestock, either through long-distance herding or trade. A combined approach using juvenile bone collagen and incrementally sectioned tooth dentine from adults demonstrates that the duration of breastfeeding varied between individuals, but that there were no significant differences in weaning practices between survivors and non-survivors. Sulphur isotopes reflect a population that was relatively homogeneous in its isotopic composition and local in origin, except for the presence of two possible migrants. The δ13C and δ15N data from the Carpathian Bend are comparable to those from contemporaneous sites in coastal and inland Greece and Croatia, suggesting a broad uniformity in Bronze Age dietary practices across Southeast Europe. As the first major stable isotope study conducted on osteological material from the Romanian Sub- Carpathians, this thesis provides new insights into the lives of these communities, expands our knowledge of Bronze Age subsistence strategies in Southeast Europe, and establishes a foundation for further isotopic investigations in the region.
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Maya osteobiographies of the Holmul region, Guatemala: curating life histories through bioarchaeology and stable isotope analysisCormier, Aviva Ann 27 November 2018 (has links)
This study applies a life history approach to analyzing the identities of 52 Maya individuals who lived between 2000 BC and AD 900 in and around the city of Holmul, within the Petén region of Guatemala. Primary goals were to: (1) identify migrant and local individuals within the urban population; (2) determine 87Sr/86Sr isotope ratio signatures for the sites of Holmul, Cival, La Sufricaya, K’o, and Hamontun; (3) compile osteobiographies, personal life histories revealed through skeletal remains, of the individuals in the sample; and (4) evaluate evidence bearing on the identities of inhabitants of the Holmul region and how they were represented within economic, political, and cultural landscapes of the ancient Maya. This work demonstrates how bioarchaeologists can implement osteobiographical analyses to advance the understanding of multifaceted social identities and individual experiences of life and death. By integrating osteological study, stable isotope analysis, and consideration of mortuary context, material culture, inscriptions, and monumental architecture, the individual, rather than the population, becomes the focus. This aggregate approach allows for an in-depth consideration of human remains as former social beings with complex identities.
The findings of this research suggest that most elite inhabitants in this ancient Maya city were local to the Holmul region, with the few outliers having originated from elsewhere in the Maya lowlands. This conclusion aligns with Maya elite ideologies of establishing lineages and reinforcing power through ancestor veneration. The local 87Sr/86Sr ratio signature of the Holmul region is comparable to other archaeological sites in the southern Maya lowlands. The osteobiographies reveal life histories, which personalize prior interpretations that considered the population only as an aggregate. This project also elucidates identities of sacrificed children, elite/royal women, and the local Holmul elite.
Results of the study support the use of the isotopic analysis of human remains as an essential tool for approaching complex archaeological questions and evaluating hypotheses previously addressed primarily using architectural, iconographic, and artifactual evidence. Further, this study demonstrates the benefit of the isotopic analysis of dental enamel, especially in the Maya region and other environments characterized by difficult excavation conditions and the poor preservation of human remains.
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Investigating the Applications of Neodymium Isotopic Compositions and Rare Earth Elements as Water Mass Tracers in the South Atlantic and North PacificWu, Yingzhe January 2019 (has links)
Neodymium (Nd) isotopes have been increasingly used to trace the modern and past ocean circulation. This assumes that seawater Nd isotope ratios (εNd) effectively fingerprint different water masses and approximate expected values from water mass mixing. However, the decoupling of Nd isotopes and Nd concentration (the “Nd paradox”) in the water column, and the lack of understanding of sources and sinks of Nd, restrain our understanding of the “quasi-conservative” behavior of εNd in seawater. Nd is one of the lanthanide rare earth elements (REEs) with similar chemical characteristics that undergo some degree of fractionation. The shale-normalized REE patterns and REE ratios can be used to investigate potential sources/sinks of REEs. Combining REEs with εNd will provide additional information to study REE cycling in the ocean.
To better understand the reliability of εNd as a water mass tracer, 17 high-resolution seawater profiles were sampled meridionally in the Southwest Atlantic (GEOTRACES GA02 Leg 3; RRS James Cook 057) and measured for εNd. This region involves the major water masses in the Atlantic Meridional Overturning Circulation: southward flowing North Atlantic Deep Water (NADW), northward flowing Antarctic Intermediate Water (AAIW) and Antarctic Bottom Water (AABW). Along the cruise track, there are potential sources (eolian dusts, marginal sediments, oceanic volcanism, and nepheloid layer) that could add external Nd to seawater and disturb the “quasi-conservative” behavior of εNd. Our results show strikingly that the Southwest Atlantic transect confirms “quasi-conservative” behavior of εNd in intermediate and deep water. Our evaluations of Nd isotopic deviations (ΔεNd) from conservative behavior show that out of 198 intermediate and deep samples, 49% of ΔεNd-values are within ± 0.25 εNd units (< analytical error: ± 0.30 εNd units) and 84% of ΔεNd-values are within ± 0.75 εNd units. Potential sources that could add external Nd to seawater from oceanic volcanism and the nepheloid layer do not show impact on seawater εNd. Terrigenous sources of Nd (e.g. eolian dusts from Africa and Patagonia, marginal sediments from South America) show influence on surface/subsurface water εNd but this εNd signature is not transferred to intermediate and deep water.
To better understand the conservative vs. non-conservative behavior of REEs in the ocean, the dissolved REE concentrations were analyzed for the 17 seawater profiles in the Southwest Meridional Atlantic Transect (GEOTRACES GA02 Leg 3). The shale-normalized REE patterns are consistent with typical seawater patterns. To investigate whether and how much REE concentrations deviate from conservative water mass mixing, the REE concentration deviations were calculated for the intermediate and deep water. It is shown that within the SAMT, the intermediate and deep water REEs generally reflect water mass mixing and nearly conservative behavior. Along this transect, the potential sources that could add external REEs to seawater are dissolution of REEs from eolian dust to the surface/subsurface water, REEs released from dissolution of Fe-Mn oxides in the oxygen depleted zone, REEs from sediments near the continental margin, and dissolution of REEs from deep sea sediments. REEs and Nd isotopes of most intermediate and deep water masses passing the volcanic Rio Grande Rise (RGR) and Vitória-Trindade Ridge (VTR) do not show influence from RGR and VTR. REEs and Nd isotopes of the bottom water Lower Circumpolar Deep Water (LCDW) and AABW passing the RGR are influenced by dissolved REEs from the deep sea sediments. LCDW and AABW passing the VTR are influenced by dissolved REEs from the deep sea sediments as well as the volcanic VTR.
In order to better understand the oceanic Nd cycling in the North Pacific, its sources and sinks in seawater must be better characterized. The high εNd of North Pacific Deep Water (NPDW, ~ −4) has been difficult to reconcile with the eolian inputs as reflected in surface waters (e.g. Jones et al., 2008), which have much lower εNd (~ −10), indicating potential addition of a component from Pacific volcanism. In order to constrain the REE sources in the North Pacific, we measured εNd and REEs of seawater from five stations across the subarctic North Pacific sampled by the Innovative North Pacific Experiment (INOPEX) Cruise SO202 (2009). In the surface water (~10 m), the highest εNd is observed at the station closest to the Aleutian-Kamchatka volcanic margin (Northwest station SO202-5), suggesting higher contribution of external REEs from volcanic ashes compared to the other stations. In the shallow water (100-400 m, depending on location), remineralization of REEs from volcanic ashes prevails over Asian dusts at Northwest station SO202-5 and near Japan stations SO202-44, 41, and 39, whereas remineralization of REEs from Asian dusts prevails over volcanic ashes at the Northeast station SO202-32 in the open ocean of the Alaska Peninsula. From the depths of North Pacific Intermediate Water (NPIW) to NPDW, seawater εNd and REEs show conservative water mass mixing of NPIW-NPDW. They also show conservative behavior along the water mass transport paths of NPIW and NPDW. Below the depths of NPDW, addition of external REEs is observed in the vertical profiles of εNd and REEs as well as along the transport path of LCDW. The potential sources that add external REEs to the bottom water are (1) sediments on the Kuril-Kamchatka-Aleutian volcanic margin along the LCDW transport path, and (2) sediments on the seafloor, both of which could interact with seawater and modify the seawater εNd and REE signatures.
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\"Síntese do glifosato marcado com nitrogênio-15\" / Synthesis of glyphosate labeled with nitrogen -15Tavares, Claudineia Raquel de Oliveira 03 February 2006 (has links)
Dentre os herbicidas atualmente comercializados, o glifosato é um dos mais utilizados no Brasil. A eficácia do glifosato, bem como de outros herbicidas, no combate às ervas daninhas, esbarra nos problemas que esses compostos acabam proporcionando ao meio ambiente. Embora estudos venham sendo realizados para elucidar melhor o comportamento de herbicidas no meio ambiente, a complexidade do comportamento desses compostos abre caminho para realização de um número significativo de trabalhos de pesquisa. Nesses estudos, é rotineiro o uso de compostos radiomarcados (traçadores radioativos) para avaliar a biodisponibilidade no solo. Todavia, o emprego, manipulação e estocagem de compostos radiomarcados exigem cuidados sob o ponto de vista da segurança, razão pelo qual o uso de isótopos não radioativos é uma tendência internacional, especialmente em pesquisas de campo. Dentre desse contexto, o trabalho descreve um método para a síntese do glifosato enriquecido no isótopo estável do nitrogênio (15N). A sintese do herbicida-15N foi realizada utilizando-se da reação de fosfometilação com diaquil fosfito e glicina-15N. Os testes foram realizados em microescala e em quantidades equimolares. Nas condições estabelecidas, foi possível alcançar um rendimento de reação de aproximadamente 25%. A otimização das condições de sintese, empregando a técnica isotópica, deverá disponibilizar uma importante ferramenta a ser utilizado em estudos referentes ao comportamento do glifosato no sistema solo-planta / Among the actual commercialized herbicides, the glyphosate is one of the most used in Brazil. Its efficiency, as well as the others herbicides, on weeds control is attached to problems that this composts cause to the environment. Although studies about the herbicides behavior in the environment have been done, the complexity of this composts behavior leads to the accomplishment of an expressive number of research works. In these works, it?s common the use of radio labeled compounds (radioactive tracers) to evaluate its bio-availability in the soil. However, the use of this radio labeled composts, its manipulation and storage demands a careful handling in the chemical security point of views. This is the reason the use of non radiactive isotopes is an international tendency, especially for field researches. According to this context, the present work describes a method for the synthesis of enriched glyphosate for the nitrogen stable isotope (15N). The tests were undertaken in micro-scale and in equimolar quantities. Under these established conditions, the reaction reached the yield of approximately 25%. The optimization of the synthesis conditions with the use of isotopic techniques shall offter an important tool to be used in studies that are referred to glyphosate behavior in soil- plant system
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Grafos e aplicações de Gauss estáveis / Graphs and stable Gauss applicationsOliveira, Flavio Henrique de 24 June 2016 (has links)
O objetivo desta dissertação é estudar grafos com pesos nos vértices como um invariante global das aplicações de Gauss estáveis de superfícies compactas e orientadas. Apresentaremos também alguns invariantes locais que são importantes no estudo de aplicações estáveis. Abordaremos o problema de realização de grafos por aplicações de Gauss estáveis, considerando também um destes invariantes, o número de cúspides destas aplicações. Finalmente, usaremos matrizes para representar estes invariantes e definiremos classes de equivalências para estes representantes. Esta foi uma ideia que surgiu no final deste trabalho de mestrado. / The propose of this work is to study graphs with weights at the vertices as a global invariant of stable Gauss applications on compact and oriented surfaces. We also present some local invariants that are important to the study of stable applications. We approach the problem of realization of graphs by stable Gauss applications, also emphasizing one of these invariants, the number of cusps of these applications. Finally, we use matrices to represent these invariants and define equivalence classes for these representatives. This idea appeared at the end of this master\'s thesis.
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Diagênese e alteração hidrotermal em rochas sedimentares da formação Corumbataí, Permiano Superior, Mina Granusso, Cordeirópolis/SP /Costa, Marcos Natal de Souza. January 2006 (has links)
Orientador: Antenor Zanardo / Banca: Jorge Silva Bettencourt / Banca: Roberto Peres Xavier / Banca: Sebastião Gomes de Carvalho / Banca: Maria Margarita Torres Moreno / Resumo: A Mina Granusso está situada nas proximidades de Cordeirópolis/SP e constitui uma fonte importante de matéria-prima para o Pólo Cerâmico de Santa Getrudes. No local aflora uma sucessão de rochas da Formação Corumbataí (Permiano Superior) constituída na base por lamitos maciços que gradam para ritmitos siltosos, passando para um horizonte psamo-pelítico e culminando em uma seqüência de ritmitos siltoarenosos. Uma feição particular é a presença de zonas de alteração hidrotermal, associadas a veios quartzo-carbonáticos e fraturas, que impuseram às rochas alterações químicas, mineralógicas e texturais. Estudos petrográficos, químicos e de DRX indicam que após a compactação mecânica houve injeção de fluidos diagenéticos em um sistema de fraturas originando veios de quartzo de baixa cristalinidade e enriquecimento de sílica de horizontes silto-arenosos. Uma nova injeção fluidal impulsionada pela ação do magmatismo basáltico acelerou a formação de albitas e deu origem a veios com calcita, quartzo, clorita e pirita. Os dados de d18O e d13C mostram que os carbonatos se precipitaram de um fluido isotopicamente homogêneo sem variações drásticas de temperatura. Valores de d13C entre -8,1 a -4,5 (PDB) indicam uma fonte profunda para o CO2 que deu origem a calcita enquanto que valores de d18O entre +18,9 e +24,1 (SMOW) sugere interações sucessivas do fluido com a rocha hospedeira e abaixamento de temperatura. / Abstract: The Granusso mine is located near the Corderopolis city and constitutes an important source of raw material to the Santa Gertrudes Ceramic Cluster. Late Permian sedimentary rocks of the Corumbataí Formation outcrops in the area. The litological succession comprises a sequence of massif, banded to laminate siltstone topped by carbonate to sandy siltstone. Hydrothermal alteration is an important feature generally associated with host rock whitening. A large basaltic sill intruded the sequence and affected the evolution of the diagenetic and hydrothermal process. Petrographic, chemical and XRD dates suggest that after the mechanical compaction a fluid injection caused the precipitation of low-cristalinity quartz and silica enrichment of sandy-siltstone horizons. A new fluid injection driven by the Serra Geral magmatism triggered albite formation and gave rise to the pyrite-chlorite-quartzcalcite veins. Carbon and oxygen isotope studies of the host rocks and veins show that carbonate precipitated from a homogeneous fluid without strong changes in temperatures along hydrothermal conducts. d13C values of -4,5 to -8,1 (PDB) indicate a CO2 deep-source while d18O of +18,4 to +24,1 (SMOW) and the positive correlarion beetween d18O and d13C values suggest a temperature-dependent trend accompanied by a progressively increasing of fluid/rock interaction. / Doutor
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\"Síntese do glifosato marcado com nitrogênio-15\" / Synthesis of glyphosate labeled with nitrogen -15Claudineia Raquel de Oliveira Tavares 03 February 2006 (has links)
Dentre os herbicidas atualmente comercializados, o glifosato é um dos mais utilizados no Brasil. A eficácia do glifosato, bem como de outros herbicidas, no combate às ervas daninhas, esbarra nos problemas que esses compostos acabam proporcionando ao meio ambiente. Embora estudos venham sendo realizados para elucidar melhor o comportamento de herbicidas no meio ambiente, a complexidade do comportamento desses compostos abre caminho para realização de um número significativo de trabalhos de pesquisa. Nesses estudos, é rotineiro o uso de compostos radiomarcados (traçadores radioativos) para avaliar a biodisponibilidade no solo. Todavia, o emprego, manipulação e estocagem de compostos radiomarcados exigem cuidados sob o ponto de vista da segurança, razão pelo qual o uso de isótopos não radioativos é uma tendência internacional, especialmente em pesquisas de campo. Dentre desse contexto, o trabalho descreve um método para a síntese do glifosato enriquecido no isótopo estável do nitrogênio (15N). A sintese do herbicida-15N foi realizada utilizando-se da reação de fosfometilação com diaquil fosfito e glicina-15N. Os testes foram realizados em microescala e em quantidades equimolares. Nas condições estabelecidas, foi possível alcançar um rendimento de reação de aproximadamente 25%. A otimização das condições de sintese, empregando a técnica isotópica, deverá disponibilizar uma importante ferramenta a ser utilizado em estudos referentes ao comportamento do glifosato no sistema solo-planta / Among the actual commercialized herbicides, the glyphosate is one of the most used in Brazil. Its efficiency, as well as the others herbicides, on weeds control is attached to problems that this composts cause to the environment. Although studies about the herbicides behavior in the environment have been done, the complexity of this composts behavior leads to the accomplishment of an expressive number of research works. In these works, it?s common the use of radio labeled compounds (radioactive tracers) to evaluate its bio-availability in the soil. However, the use of this radio labeled composts, its manipulation and storage demands a careful handling in the chemical security point of views. This is the reason the use of non radiactive isotopes is an international tendency, especially for field researches. According to this context, the present work describes a method for the synthesis of enriched glyphosate for the nitrogen stable isotope (15N). The tests were undertaken in micro-scale and in equimolar quantities. Under these established conditions, the reaction reached the yield of approximately 25%. The optimization of the synthesis conditions with the use of isotopic techniques shall offter an important tool to be used in studies that are referred to glyphosate behavior in soil- plant system
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Lake Powell Food Web Structure: Predicting Effects of Quagga MusselVerde, Joshua A. 01 April 2017 (has links)
Food webs in aquatic ecosystems can be dramatically altered by invasive species. Quagga mussels are prevalent invaders that compete with existing species and disrupt nutrient cycling. In 2012, the Quagga Mussel (Dreissena rostriformus bugensis) was introduced into Lake Powell and is expected to move throughout the reservoir in the near future. Stable isotope analysis is a powerful tool for characterizing food webs and trophic interactions. To predict the long-term effects of Quagga Mussels, we used stable isotope analysis of primary producers, primary consumers, prey fish species, and predator fish species in Lake Powell to determine food web structure. Quagga Mussel are positioned to disrupt the pelagic arm of the food web by interfering with the link between phytoplankton and herbivorous zooplankton. This will likely have negative impacts on pelagic fish such as striped bass (Morone saxatilis) and threadfin shad (Dorosoma petenense). Quagga Mussel may also boost benthic productivity in the littoral zone by diverting nutrients from the water column to the benthos. This may have positive impacts on littoral fishes such as largemouth bass (Micropterus salmoides), smallmouth bass (Micropterus dolomieu), bluegill (Lepomis macrochirus), and green sunfish (Lepomis cyanellus).
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High-resolution chronostratigraphic correlation of Upper Homerian (Silurian) strata during the Mulde event, midcontinent, USADanielsen, Erika M. 01 May 2017 (has links)
The upper Homerian Mulde Event was a mass extinction that devastated graptolite diversity and occurred before and during the onset of a major perturbation to the global carbon cycle recorded as a double-peaked positive carbon isotope excursion (CIE). Whereas the Mulde Event and associated CIE are well-documented globally, changes in global sea level associated with the Mulde Event have only been investigated in detail in the West Midlands, England and Gotland, Sweden. A critical step toward understanding both the drivers and results of global climatic change during the Mulde Event is to constrain changes in eustasy. This study integrates carbon isotope chemostratigraphy and conodont biostratigraphy of Homerian strata in Tennessee, Indiana, and Ohio in an effort to determine if a global type-1 sequence boundary is recorded within the ascending limb of the Mulde CIE, and to produce a high-resolution chronostratigraphic framework for Homerian strata in the midcontinent USA. Six sections, two from each state, were measured and described. Five were sampled for carbon isotope chemostratigraphy, and one for conodont biostratigraphy. All sections from Tennessee and Indiana evidently contain the Mulde CIE, whereas the sections from Ohio are less clear due to the truncation of upper Homerian strata. These data demonstrate that a sequence boundary identified herein in Indiana and Tennessee is the same sequence boundary that occurred during the ascending limb of the Mulde Excursion in the West Midlands and Gotland.
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Orbital- to millennial-scale variability in Gulf of Mexico sea surface temperature and salinity during the late PleistoceneWhitaker, Jessica L 26 June 2008 (has links)
Sea surface temperature (SST) reconstructions from the low latitudes indicate the tropics/subtropics warmed significantly before glacial-interglacial decreases in global ice volume, suggesting the importance of tropical and subtropical climate in driving glacial terminations.
ODP Site 625, drilled at a water depth of 889 m near De Soto Canyon in the Gulf of Mexico (GOM), provides continuous records of marine isotope stages (MIS) 1-6 sampled at a mean temporal resolution of 400 years. Age control is based on 8 AMS radiocarbon dates, marine isotope stratigraphy, and Foraminifera datum levels. Results from Globigerinoides ruber (white variety) Mg/Ca-SST indicate a rise of 4.4 °C from last glacial maximum to modern conditions and a 3.2 °C rise from the penultimate glaciation to the last interglaciation.
However, model results suggest reduced thermohaline circulation (THC) causes salt and heat build-up in the Atlantic Warm Pool. Paired G. ruber Mg/Ca-SST and δ18O provide evidence of sub-millennial scale variability in GOM SST and SSS that is probably influenced by the strength of NADW production, as also observed in the Western Caribbean Sea.
We test the idea that widespread abrupt climate change during the last glaciation caused by millennial scale fluctuations in the intensity of THC was modulated by Laurentide ice sheet (LIS) meltwater routed to the North Atlantic. To understand LIS melting dynamics and test the Meltwater Routing Hypothesis, we investigate the phasing of GOM SST and LIS freshwater events in relationship to high latitude climate. Estimated salinities from our multi-proxy approach suggest three freshwater events with a major freshwater influx from that occurred during Heinrich Event 2. This result confirms previous studies that suggested LIS summer melting during warmings in Antarctica.
We also find a climate reversal during termination II from 130.4-128.4 ka. The initial rise in GOM SST at 132.1 ka of 2.9 °C is followed by a cold reversal of 1.5 °C at 130.4 ka for 2 ky and final increase to full interglacial warmth. The reversal in GOM SST is consonant with a pause in sea level rise and reduced NADW, suggesting a reduction in THC may have caused a global two-step deglaciation.
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