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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.
121

Contribuição à geologia da região de São José dos Quatro Marcos - MT / Not available.

Carneiro, Maurício Antônio 16 May 1986 (has links)
O mapeamento geológico (escala 1:100.000) realizado na região de São José dos Quatro Marcos, sudoeste de Mato Grosso, revelou marcada variedade litológica. Predominam, como rochas consideradas do embasamento, gnaisses cinzentos e tonalíticos, com lentes e bandas interestratificadas de anfibolitos (\"primeira geração\") e escassas ocorrências de granulitos. Gnaisses róseos oftalmíticos, de composição granítica, são considerados granitóides porfiríticos deformados, enquanto que alguns afloramentos de rochas calco-silicáticas bandadas são representantes de sequências supracrustais deformadas e metamorfisadas. Estas rochas são invadidas por várias fácies de granitóides róseos e cinzas, tanto maciços como orientados. Petrograficamente, são tonalitos, granodioritos e granitos 3a e 3b, que aparecem no campo como blocos isolados e geralmente alternantes (i.e. maciços \"não circunscritos\"), colocados numa sequência que se inicia com tonalitos precoces e finaliza como granitos tardios. Estes granitóides mostram enclaves de gnaisses cinzentos e de anfibolitos (\"segunda geração\"). Um corpo anfibolítico de dimensões maiores, aflorando a W da área mapeada, é considerado também de \"segunda geração\". Para leste, aparecem alguns afloramentos isolados de riólitos porfiríticos, com matriz esferulítica. Todas as unidades mencionadas são descritas petrograficamente, apresentando-se adicionalmente várias dezenas de modas de gnaisses cinzentos, anfibolitos, rochas calco-silicáticas e granitóides. As observações geológicas são lançadas num \"mapa de domínios petrográficos\", que mostra a distribuição, no campo, dos tipos petrográficos dominantes. Determinações radiométricas pelo método Rb/Sr mostram idades isocrônicas de 1971 \'+ OU -\' 70 ma. (quatro amostras de um único afloramento) para gnaisses cinzentos, e 1472 \'+ OU -\' 19 ma. (seis amostras) para granitóides róseos; as razões iniciais são 0,7017 e 0,7037 respectivamente, indicando evolução a partir de materiais primitivos. Idades K/Ar em gnaisses cinzentos e anfibolitos são da ordem de 1500 ma. A área mapeada é parte integrante de uma \"faixa deformada\" de maior extensão, com os gnaisses cinzentos formando o embasamento para rochas supracrustais (calco-silicáticas), com posterior invasão de granitóides \"não circunscritos\", que marca, por volta de 1500 ma., um evento térmico-tectônico relacionado à \"reativação\" Parguazense (ciclo San Ignacio). As correlações com unidades formais definidas em áreas vizinhas, são dificultadas pela falta de mapeamento de maior detalhe. Considera-se prematura a atribuição das rochas do embasamento (gnaisses cinzentos, etc.) ao Complexo Xingu, originalmente definido na Amazônia Central. As rochas calco-silicáticas, remanescentes de sequências supracrustais mais espessas, são possíveis equivalentes de pacotes semelhantes já mapeados em áreas vizinhas, (e.g. Sequência Vulcano Sedimentar Quatro Meninas). As rochas granitóides foram geradas provavelmente por anatexia da crosta primitiva, e pertencem a \"Suíte Intrusiva Guapé\" como redefinida no presente trabalho. Os anfibolitos de corpos maiores \"segunda geração\" são os equivalentes da Suíte Intrusiva Rio Alegre, enquanto que os riólitos são prováveis cronocorrelatos do Grupo Rio Branco. / Geologic mapping (1: 100,000) in São José dos Quatro Marcos, southwestern State of Mato Grosso, showed a remarkable lithological variety. Predominant, among basement rocks, are grey tonalitic gneisses, with interlayered \"first generation\" amphibolite lenses and bands and rare granulite occurrences. Associated pink granitic gneisses, with ophtalmitic structures are probably deformed early porphyritic granites. Sparse outcrops of banded calc-silicate rocks are rermmants of supracrustal sequences. These rocks are invaded by several facies of pink and grey granitoid types, both massive and slightly oriented, which are petrographically tonalites, granodiorites and 3a - 3b granites. These granitoids are observed in the field as isolated blocks of very variable petrography, intruded in a time sequence starting with tonalites, and ending with late pink granitoids. Granitoids show enclaves of both grey gneisses and \"second generation\" amphibolites; a larger amphibolite body, observed in the western part of the mapped area, is also considered part of this \"second generation\" sequence. To the E, scattered outcrops of porphyritic rhyolites, with a spherulitic matrix; were observed. All the mentioned units were described petrographically; several tens of modes of grey gneisses, amphibolites, calc-silicate rocks and granitoids are also presented. Geologic observations are shown in a \"map of petrographic domains\", which identifies, as objectively as possible, the distribution pattern of the rock types. Two Rb/Sr isochrons are presented, one for grey gneisses (four points of a single outcrop), yielding an age of 1971 \'+ ou -\' 70 ma., the other for the granitoid intrusives (six points), with an age of 1472 \'+ ou -\' 19 ma. Small initial ratios (0.7017 for grey gneisses, 0.7037 for granitoids), suggest that these rocks originated from metamorphism and/or partial fusion of primitive material, K/Ar ages cluster around 1500 ma. both for grey gneisses and several samples of amphibolites. The mapped area is part of a \"deformed belt\" of greater dimension; grey gneisses are considered basement rocks, upon which supracrustal sequences (calc-silicate rocks) were deposited, later invaded by a network of granitoids. The last occurrences, dated at about 1500 ma, marked a significant thermal and tectonic event, probably associated with the Parguazense \"reactivation\" (San Ignacio cycle). Correlation with other units, formally defined in nearby areas, is difficult, on account of the lack of detailed mapping of regional extent. There is no supporting data for defining the grey gneisses as \"Xingu Complex\" rocks, since this last unit was originally defined in Central Amazônia. Calc-silicate rocks are probably equivalent of thicker supracrustal sequences mapped in the vicinity (e.g. the Quatro Meninas volcanic-sedimentary sequence). The granitoid rocks, probably generated by anatexis of primitive crust, is correlated with the \"Guapé Intrusive Suite\", as here redefined. Amphibolites of the second genoration (specially the larger bodies) are probably equivalent to the \"Rio Alegre Intrusive Suite\" of basic rocks, while rhyolites are tentatively compared with the volcanic rocks of the Rio Branco Group.
122

Microbial Biodiversity of Thermophilic Communities in Hot Mineral Soils of Tramway Ridge, Mt. Erebus, Antarctica

Soo, Rochelle January 2007 (has links)
Only a few studies have looked at microbial biogeography in soils and whether microorganisms are endemic to an area is still debatable. Tramway Ridge, a geothermal area on Mount Erebus, Antarctica, provides a unique opportunity due to its isolation and extreme conditions to explore the possibilities of microbial endemism and to identify novel Bacteria and Archaea. This site was chosen for a culture-independent study with a preliminary culturing survey for bacterial communities along three temperature gradients (65 C - 2.5'C). In addition, a physico-chemical analysis was undertaken to identify which environmental factors were driving the different diversity along the transects. An automated rRNA intergenic spacer analysis (ARISA) was used to assess the diversity across the transects using Bacteria and Cyanobacteria-specific primers and results showed that temperature and pH were the main drivers for these communities. Due to its unique physico-chemical and ARISA profile, a hot temperature site (T-3A, 65'C) was chosen for further investigation by bacterial and archaeal 16S rDNA clone libraries. Unique rDNA types among the 78 bacterial and 83 archaeal clones were identified by restriction fragment length polymophisms and 18 bacterial and 5 archaeal operational taxonomic units (gt97% identity) were observed. All of the bacterial sequences were deeply branching and loosely affiliated with other recognised bacterial divisions, with 40% of the sequences not affiliated to any genus. The archaeal clones were found to be deep-branching and sequences clustered together within the Crenarcaheota. In addition, two strains of Bacilli were isolated. The novel microorganisms show that the Tramway Ridge communities are unique from organisms found in other environments and show that quotEverything is (not) everywherequot.
123

PCR-RFLP analys av mt-DNA hos Öring (Salmo trutta) i Gävleborgs län.

Björkbom, Tommy January 2010 (has links)
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124

Escalation of Commitment in Temporary Organisations : A Case Study of the 1996 Mt. Everest Disaster

Pustina, Aferdita, Aegerter Alvarez, Juan Felipe January 2010 (has links)
<p> </p><p>In an organisation, escalation of commitment represents behaviour of decision makers who become committed to failing courses of action. This behaviour usually derives from the decision makers’ reluctance to acknowledge their failed action in the initial allotment of time and resources, and thus taking actions to manifest their prior decision were correct and they will be achieving the planned goal.</p><p> </p><p>In a single day of 1996 during a climbing expedition destined to summit Mt Everest, eight people lost their lives, including the climbing team leaders, in part due to the decision made that led to the teams to engage in escalation behaviour.  The climbing teams in the 1996 Mt Everest expedition serve as examples of temporary organisations in an extreme setting. The purpose of the research is to explore insights on the aspects promoting escalation on the Mt Everest tragedy and shed some light into how escalation manifests in temporary organisations. The factors that might be found will be applicable only to this particular case; nevertheless they might contribute on the overall development of how escalation comes about in temporary organisations. The research question of this study is how aspects promoting escalation where present in the 1996 Mt. Everest expedition?</p><p> </p><p>For many years different theories attempted to explain the factors that promote escalation behaviour. The most important theories were combined together into a theoretical framework developed by Staw and Ross (1987a), which contains four major determinants of commitment in escalation: project, psychological, social and organisational. This framework is applied in this qualitative study based on the 1996 Mt Everest case. The study was executed through the analysis of the firsthand accounts of the survivors and observers present on the mountain that year as well as mass media outputs, the framework of escalation was used as an assistance tool for making sense of the findings the research may produce.</p><p> </p><p>The results of the study managed to place the line of events in the determinants framework and identified all four types of determinants of commitment taking place through the progress of the expedition. A new organisational determinant of commitment was found (<em>pursuit of enterprise growth</em>) which yielded significant practical implications and might also lead the way for future research on escalation of commitment in temporary organisations.</p>
125

PCR-RFLP analys av mt-DNA hos Öring (Salmo trutta) i Gävleborgs län.

Björkbom, Tommy January 2010 (has links)

126

Sequence Stratigraphy and Detrital Zircon Geochronology of Middle-Late Ordovician Mt. Wilson Quartzite, British Columbia, Canada

Hutto, Andrew Paul 2012 May 1900 (has links)
Middle-Late Ordovician Mt. Wilson Quartzite, southern British Columbia, Canada, is a supermature quartz arenite deposited in shallow marine-marginal marine environments on the Early Paleozoic western Laurentian passive margin. Facies-stacking patterns indicate the Mt. Wilson Quartzite is an unconformity bounded, 2nd-order depositional sequence, containing two 3rd-order sequences, and numerous parasequences. Detrital zircon age spectra of six samples of the Mt. Wilson Quartzite have numerous peaks that are unique to Middle to Late Ordovician quartz arenites of western Laurentia. The main peaks, 1800-2000 Ma, 2000-2200 Ma, and 2300-2400 Ma are interpreted to have been derived from basement rocks that were exposed east of the study area: Trans-Hudson Orogeny (1800-2000 Ma), Taltson Orogen (1800-2000 Ma), Buffalo Head Terrane (2000-2400 Ma), Paleoproterozoic crust (2000-2400 Ma), and the Wopmay Terrane (2000-2400 Ma). It is likely that these areas were sourced by local rivers and tributaries draining the Transcontinental Arch and delivered sediment to the deposition location of the Mt. Wilson Quartzite. While longshore transport was a viable distribution method for sediment along the passive margin, it is unlikely that the Peace River Arch (located northwest of the Mt. Wilson Quartzite) was its sole point source; rather it is more likely that there were multiple sediment sources for these western Laurentian quartz arenites. Temporal changes in provenance indicate different areas of basement rock were exposed throughout the deposition of the Mt. Wilson Quartzite, most likely reflecting long-term flooding of North America. The potential for spatial changes in provenance remains unsolved.
127

A study of geophagy in Formosan macaques, Macaca cyclopis, at Mt. Longevity, Taiwan.

Chia, San-Ming 29 July 2002 (has links)
Soil in the Mt. Longevity, Taiwan, eaten by Formosan macaques, was analyzed to determine the possible stimulus or stimuli for geophagy. I attempted to test the mineral supplementation hypothesis and to document macaques using particle size. I studied macaques soil-eating behavior from July 2000 to April 2002 in the Mt. Longevity, Taiwan, and analyzed soil samples eaten and uneaten by Formosan macaque for physical-chemical properties and geochemistry in the study area. The results show that samples of soil eaten contained relatively high iron ( 3.6% ) and aluminum ( 16.0% ). However, the concentration of samarium was significantly lower in soil from samples eaten than in the random samples. No difference in concentration of the remaining fifteen elements ( magnesium¡Bcalcium¡B chromium¡Bmanganese¡Bcopper¡Barsenic¡Bstrontium¡Bbarium¡Blanthanum¡Bcerium¡Bneodymium¡Bytterbium¡Bphosphorous¡Bsulfate¡Bchlorides ) and Nitrate nitrogen was found between these two groups of soil samples. Geophagy occurred at a high rate of 0.31 monkey per hour with an elevated frequency in the reproduction season. The density of geophagy has been estimated as 1.6¡Ñ103 individuals per km2 . Frequency of male geophagy were recorded highest in September. Frequency of Females eating soil was recorded mainly between February and April. The ingested soils were significantly richer in clay than control soils. This study supports the hypothesis that mineral supplementation is a major factor for Formosan macaque engaging in geophagy.
128

Dynamics of Cortical Decision Circuits during Changes in the Fidelity of Sensory Representations

Smolyanskaya, Alexandra 06 October 2014 (has links)
Every waking moment, we make decisions, from where to move our eyes to what to eat for dinner. The ease and speed with which we do this belie the complexity of the underlying neuronal processing. In the visual system, every scene is processed via a complicated network of neurons that extends from the retina through multiple areas in the visual cortex. Each decision requires rapid coordination of signals from the relevant neurons. Deficits in this integration are likely causes of debilitating learning disorders, yet we know little about the processes involved. Previous studies of the macaque visual cortex indicate that as monkeys learn a new task the parts of the brain involved in decision making select which neurons they “listen to”: the most informative neurons become more strongly associated with the animal’s decisions as it learns. However, this process has only been studied over the course of several months as monkeys gradually learn a complex task. We set out to probe the dynamics of this relationship on a shorter timescale. We studied the middle temporal area (MT) of the visual cortex, where neurons are selective for binocular disparity (a depth cue) and motion direction; they have also been shown to contribute to perceptual decisions during motion- and depth-based tasks. After training monkeys on motion and depth detection tasks, we degraded the sensitivity of MT neurons for depth more than motion by reversibly inactivating two major inputs to MT—visual areas V2 and V3—by cooling. We hypothesized that degrading depth information more than motion would lead to bigger changes in the extent to which MT neurons contributed to decisions during the depth task than the motion task. We monitored this contribution to decisions, as measured by detect probability (DP), prior to and during daily inactivation sessions. We found that neuronal DP decreased during the depth task, indicating that neurons became less involved in these decisions. DP did not change during the motion task, suggesting that these changes can be specific to one feature. Our results revealed a level of fast, selective flexibility in the decision circuitry.
129

A system for the analysis of musical data

Pullinger, Stuart January 2010 (has links)
The role of music analysis is to enlighten our understanding of a piece of music. The role of musical performance analysis is to help us understand how a performer interprets a piece of music. The current work provides a tool which combines music analysis with performance analysis. By combining music and performance analysis in one system new questions can be asked of a piece of music: how is the structure of a piece reflected in the performance and how can the performance enlighten our understanding of the piece's structure? The current work describes a unified database which can store and present musical score alongside associated performance data and musical analysis. Using a general purpose representation language, Performance Mark-up Language (PML), aspects of performance are recorded and analysed. Data thus acquired from one project is made available to others. Presentation involves high-quality scores suitably annotated with the requested information. Such output is easily and directly accessible to musicians, performance scientists and analysts. We define a set of data structures and operators which can operate on musical pitch and musical time, and use them to form the basis of a query language for a musical database. The database can store musical information (score, gestural data, etc.). Querying the database results in annotations of the musical score. The database is capable of storing musical score information and performance data and cross-referencing them. It is equipped with the necessary primitives to execute music-analytical queries, and highlight notes identified from the score and display performance data alongside the score.
130

Escalation of Commitment in Temporary Organisations : A Case Study of the 1996 Mt. Everest Disaster

Pustina, Aferdita, Aegerter Alvarez, Juan Felipe January 2010 (has links)
In an organisation, escalation of commitment represents behaviour of decision makers who become committed to failing courses of action. This behaviour usually derives from the decision makers’ reluctance to acknowledge their failed action in the initial allotment of time and resources, and thus taking actions to manifest their prior decision were correct and they will be achieving the planned goal.   In a single day of 1996 during a climbing expedition destined to summit Mt Everest, eight people lost their lives, including the climbing team leaders, in part due to the decision made that led to the teams to engage in escalation behaviour.  The climbing teams in the 1996 Mt Everest expedition serve as examples of temporary organisations in an extreme setting. The purpose of the research is to explore insights on the aspects promoting escalation on the Mt Everest tragedy and shed some light into how escalation manifests in temporary organisations. The factors that might be found will be applicable only to this particular case; nevertheless they might contribute on the overall development of how escalation comes about in temporary organisations. The research question of this study is how aspects promoting escalation where present in the 1996 Mt. Everest expedition?   For many years different theories attempted to explain the factors that promote escalation behaviour. The most important theories were combined together into a theoretical framework developed by Staw and Ross (1987a), which contains four major determinants of commitment in escalation: project, psychological, social and organisational. This framework is applied in this qualitative study based on the 1996 Mt Everest case. The study was executed through the analysis of the firsthand accounts of the survivors and observers present on the mountain that year as well as mass media outputs, the framework of escalation was used as an assistance tool for making sense of the findings the research may produce.   The results of the study managed to place the line of events in the determinants framework and identified all four types of determinants of commitment taking place through the progress of the expedition. A new organisational determinant of commitment was found (pursuit of enterprise growth) which yielded significant practical implications and might also lead the way for future research on escalation of commitment in temporary organisations.

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