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Composição florística e fitossociologia de duas áreas de caatinga no Parque Nacional do Catimbau, Buíque, Pernambuco, Brasil / Floristic composition and phytosociology of two savanna sand areas of Parque Nacional do Catimbau, Buíque, Pernambuco, BrazilSERAFIM FILHO, Gilvan Lopes 19 February 2014 (has links)
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Previous issue date: 2014-02-19 / Despite the existence of floristic-phytosociological studies of savanna vegetation, very little is known about the vegetation types in this biome as a whole. In this sense there is a consensus among various authors about the need to recognize the heterogeneity and floristic his face. Climate and soil, or together, these two factors are considered key in determining this floristic heterogeneity. The aim of this work was to floristic and phytosociological study in two fragments of woody savanna (Trilha do Cânion¹ and Casa do Artesão²), located in the municipality of Buíque - PE, in sedimentary areas (Quartzipsamments Neosol). Through the method of the quadrants, we studied 10 transects parallel and equidistant 30m transects were demarcated in 10 points every 10m, being sampled individuals (trees, saplings, shrubs and succulents), closer to the center of each quadrant, dead or alive (standing still) with the girth ≥ 9 cm from ground level. For each zone were sampled quadrants 100, 400 points, resulting in 400 individuals. In one area, we sampled 16 families, 24 genera and 26 species, as in area 2, the inventory indicated nine families, 20 genera and 27 species. The families with the largest number of species in area 1 were Fabaceae, Cactaceae and Myrtaceae, in area 2 were: Fabaceae, Euphorbiaceae and Verbenaceae. Already the most abundant taxa were Byrsonima gardneriana and Chamaecrista brachystachya (1), followed by Pityrocarpa moniliformis and Amburana cearensis (2). In area 1, and Fabaceae families Cactaceae showed the highest values of sampled individuals, 18,52 and 14.81% spp. In area 2 highlights were Fabaceae (28.57%), Euphorbiaceae (28.57%) and Verbenaceae (10.71%), households with higher (spp%) include those typically found in sedimentary environments. The vegetation structure was evaluated by the usual parameters by making use of the software FITOPAC (Shepherd, 1995), we determined the number of individuals (NInd), relative density (RelDe), relative frequency (RelFr), relative dominance (RelDo), IVI and IVC for Family / species in the two areas surveyed, among other parameters phytosociological. The analysis results showed that the two areas differ both in physiognomy and in vegetation structure and low species richness. / Apesar da existência de estudos florístico-fitossociológicos da vegetação de caatinga, muito pouco se conhece sobre as fitofisionomias desse bioma como um todo. Neste sentido há um consenso entre vários autores sobre a necessidade em reconhecer a heterogeneidade florística e sua fisionomia. Clima e solo, ou o conjunto desses dois fatores, são considerados os principais quanto à determinação dessa heterogeneidade florística. O objetivo do presente trabalho foi realizar um estudo florístico e fitossociológico em dois fragmentos de caatinga arbustivo-arbóreo (Trilha do Cânion1 e Casa do Artesão2), localizados no município de Buíque - PE, situados em áreas sedimentares (Neossolos quartzarênicos). Através do método dos quadrantes, foram estudados 10 transectos paralelos e equidistantes 30m, nos transectos foram demarcados 10 pontos a cada 10m, sendo amostrados os indivíduos (árvores, arvoretas, arbustos e suculentas), mais próximos do centro de cada quadrante, vivos ou mortos (ainda de pé), com perímetro do caule ≥ 9cm ao nível do solo. Para cada área foram amostrados 100 quadrantes, 400 pontos, resultando em 400 indivíduos. Na área 1, foram amostradas 16 famílias, 24 gêneros e 26 espécies, já na área 2, o inventário apontou nove famílias, 20 gêneros e 27 espécies. As famílias com maior número de espécies na área 1 foram Fabaceae, Cactaceae e Myrtacee, na área 2 foram: Fabaceae, Euphorbiaceae e Verbenaceae. Os táxons mais abundantes foram Byrsonima gardneriana e Chamaecrista brachystachya (1), seguido de Pityrocarpa moniliformis e Amburana cearensis (2). Na área 1, as famílias Fabaceae e Cactaceae apresentaram os maiores valores de indivíduos amostrados, 18,52 e 14,81% spp. Na área 2 destacaram-se as famílias Fabaceae (28,57%), Euphorbiaceae (28,57%) e Verbenaceae (10,71%), as famílias com maior (%spp) compreendem as tipicamente encontradas em ambientes sedimentares. A estrutura da vegetação foi avaliada através dos parâmetros usuais fazendo-se uso do software FITOPAC (Shepherd, 1995), foram determinados o número de indivíduos (NInd), Densidade relativa (RelDe), Frequência relativa (RelFr), Dominância relativa (RelDo), IVI e IVC para Família/Espécies nas duas áreas inventariadas, entre outros parâmetros fitossociológicos. Os resultados das análises evidenciaram que as duas áreas apresentaram diferenças tanto na fisionomia quanto na estrutura vegetacional, bem como baixa riqueza florística.
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O imaginário da educação no romance Estrada da liberdade, de Alina Paim / THE IMAGINARY ROAD OF EDUCATION IN ROMANCE FREEDOM OF ALINA PAIM.Santos, Fabiana dos 29 July 2011 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This paper has two integrated objectives: the first one concerns the presentation and dissemination of the academic work of Alina Paim, particularly her first novel The Freedom
Road (1944), and the second one refers to analysis of the imagery of female education through the Bildungsroman theory in the work of the writer in question. The work is
addressed in two dimensions: the formation of the image of woman / teacher and its social context, which brings us to the theme of struggle of gender and proletarian class exposed by Paim in her work. This analysis, that goes from the history of female education to the construction of the ideals of the teacher in society, seeks to draw a perspective of how women
have achieved their independence in social and personal contexts, moving from private to public areas, without losing the essence. A second dimension of the study is the analysis of traces of female education and transformation (the Bildung), through education, within the literary work. In the novel The Freedom Road, the trajectory of Marina is a fine example of how education and female instruction, even with the strong social stereotypes present at the time, change the position of women to others and to herself. In order to accomplish these goals, The material used was the theoretical support from the studies of history and women's education by Mary Del Priore, Guaraci Lopes Louro, Jane Adams, Elodia Xavier, among others, regarding the history of the process of educational and professional formation of women in Brazil; Cristina Ferreira Pinto, Wilma Patricia Maas, Eduardo Assis Duarte, among others, regarding the Bildungsroman theory, or novel of formation and learning, which fits our work perfectly. This research aims to lead to a reflection that focuses on women's position in society which was already discussed by Paim in the 40's, being inserted into the literary tradition, and giving proof to the changing role of education and the novel female formation. / O presente trabalho possui dois objetivos integrados: o primeiro diz respeito à apresentação e divulgação no meio acadêmico da obra de Alina Paim, em especial seu primeiro romance Estrada da Liberdade (1944); e o segundo, refere-se à análise do imaginário da educação feminina, através da teoria do Bildungsroman, na obra da escritora sergipana em questão. A obra é abordada em duas dimensões: a formação da imagem da mulher/professora e sua atuação social, que nos remete a temática proletária e de luta de classe e gênero exposta por Paim em sua obra. Essa análise, que parte da história da educação feminina até a construção do ideário da professora na sociedade, busca traçar uma perspectiva de como a mulher conquistou sua autonomia no âmbito social e pessoal, passando do espaço privado ao público, sem perder sua essência. Uma segunda dimensão do estudo é a análise dos traços de formação e transformação feminina (o Bildung), através da educação, dentro da obra literária. No romance Estrada da Liberdade, a trajetória de Marina é o exemplo de como a educação e a instrução feminina, mesmo com os fortes estereótipos sociais, mudam a posição da mulher
perante os outros e diante de si mesma. Para que esses objetivos fossem alcançados, foram utilizados como suporte teórico os estudos de História e Educação feminina de Mary Del Priore, Guaracira Lopes Louro, Jane Almeida, Elódia Xavier, entre outros, no tocante à história do processo educacional e profissional femininos no Brasil; Cristina Ferreira Pinto, Wilma Patrícia Maas, Eduardo Assis Duarte, entre outros, no que diz respeito ao Bildungsroman, ou seja, romance de formação e aprendizagem, que se enquadra perfeitamente em nosso trabalho. Essa investigação pretende conduzir à reflexão que focalize a posição da mulher na sociedade, que já era discutido por Paim na década de 40, o que a insere na tradição literária, além de provar o papel transformador da educação e do romance de formação feminino.
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Estilos estruturais relacionados à tectônica formadora e deformadora da bacia de Jaibaras, Nordeste do Brasil / not availableLaura Catalina Roman Garcia 29 September 2016 (has links)
A Bacia de Jaibaras, localizada no nordeste do Brasil, faz parte de um sistema de rifts ediacarano a cambriano desenvolvido, em grande parte, sob a Bacia do Parnaíba, como demostram os dados geofísicos. Esta bacia teve o seu desenvolvimento estreitamente ligado ao sistema de falhas do Lineamento Transbrasiliano, representado nas suas bordas. No presente trabalho foi realizada a análise estrutural do preenchimento vulcano-sedimentar da bacia visando à reconstituição da evolução dos campos de paleotensões atuantes durante a sua instalação e deformação. O estudo foi sustentando essencialmente em observações feitas em campo e complementado com o exame de dados de sísmica de reflexão, gravimetria e magnetometría. Deste modo procurou-se contribuir na discussão sobre a classificação da bacia, tópico amplamente discutido mas até então não abordado sob a perspectiva do tectonismo gerador e deformador da Bacia de Jaibaras. A instalação da bacia esteve marcada provavelmente pelo mesmo campo de esforços distensivos de direção NNW-SSE responsável pela intrusão do enxame de diques Coreaú. Em seguida, esta direção regionalmente sofreu rotações que determinaram a continuidade da instalação, deformação e inversão do rift. As estruturas na Formação Pacujá, de idade EdiacaranoCambriano, mecanicamente coerentes com este estágio, compreendem falhas de direção NE-SW reativadas com sentido transcorrente dextral, com componente normal; falhas de direção ENE-WSW sin- e pós-sedimentares e falhas de transferência de direção NW-SE. Associadas à propagação das falhas de direção ENE-WSE sin-sedimentares formaram-se dobras. Dobras também ocorrem em posição transversal a estas falhas relacionadas com deslocamento diferenciais nas rampas de revezamento. Estas estruturas ensejaram a criação de um sistema de drenagem axial, um sistema deltaico associado às rampas de revezamento e cones de talude transversais. Na Formação Parapuí, coetânea, ocorrem múltiplas famílias de veios de calcita. A mais antiga apresenta direção N-S e foi preenchida sob a ação de campo de esforços distensivo na direção ENE-WSW. Posteriormente formaram-se veios de calcita de direção E-W, tentativamente correlacionados com as falhas sin-sedimentares da Formação Pacujá, originadas por uma distensão de direção aproximada N-S. Na Formação Aprazível se registram diques clásticos de idade ordoviciana que seriam coerentes com uma direção distensiva NW-SE. Um campo de esforços compressivo E-W a ENE-WSW atuante a partir do Ordoviciano tardio gerou estruturas transpressivas ao longo de certos segmentos de direção ENE-WSW, ocasionando uma fraca inversão da bacia. Este evento está representado por dobras cônicas de arrastro geradas durante a inversão de falhas normais para reversas, com componente transcorrente. Na Formação Parapuí este evento pode ter determinado a formação de veios de calcita de direção ENE-WSW com componente dextral e veios sigmoidais en échelon com a mesma orientação. Tanto na Formação Pacujá como na Formação Parapuí está registrado um evento final representado por fraturas abertas de orientação aproximada E-W (distensão de direção N-S), que encontrariam correlação com o campo de esforços obtido pela orientação de diques clásticos na Formação Ipu (Siluriano) da Bacia do Parnaíba, assim como o arranjo de juntas híbridas medidas na mesma formação. A importância da atividade de falhas transversais produto das movimentações transcorrentes ao longo do sistema de falhas do Lineamento Transbrasiliano leva a considerar que a cinemática transcorrente foi desencadeadora da subsidência no rift e posteriormente da deformação durante a inversão. Por estes motivos, com relação à classificação da Bacia de Jaibaras considera-se que esta estaria mais próxima de uma bacia de pull-apart do que um rift puro. / The Jaibaras Basin, in northeastern Brasil, is a part of an Ediacaran to Cambrian rift system that branches under the Parnaiba sag basin, as evidenced by geophysical data. The basin is closely related to the Trasnbrasiliano Lineament fault system, represented in both its boundaries. The present study comprises a structural analysis of the volcano-sedimentary infill of the basin, aiming to the reconstruction of the paleostress field evolution responsible for the installation, deformation and inversion of the basin. This analysis was supported by sedimentological observations in the field and complemented with revision of seismic lines, gravimetric and magnetometric maps. The study aims to contribute to the discussion of the classification of the basin, a widely reviewed topic but few times from a sedimentary infill deformation perspective. The Jaibaras Basin initiation was probably related to the samestress field responsible for the intrusion of the Coreaú dyke swarm under a NNW-SSEoriented paleostress field. Subsequently the paleostress field rotated causing both the deformation and inversion of the rift. In the Ediacaran to Cambrian Pacujá Formation were identified several mechanically consistent structures with the NNW-SSE-oriented paleostress field: longitudinal NE-SW-oriented faults with right-lateral strike-slip reactivation with a normal component; transverse ENE-WSW-oriented faults with both syn- and- post- sedimentary activity and transfer NW-SE-oriented faults. Associated with the ENE-WSW-oriented syn-sedimentary faults normal fault-propagation-folds formed. Additionally transverse folds were formed related to the differential slip along the normal faults. The above-described structures determined the installation of an axial drainage system, a deltaic setting associated to rely ramps and transversal talus cones. In the contemporary Parapuí Formation, locally occurred the formation N-S-oriented calcite veins caused by an ENE-WSW-oriented extensional paleostress field. Then followed the formation of the E-W-oriented calcite veins tentatively correlatable to the syn-sedimentary faults in the Pacujá Formation, formed under an approximately N-S-oriented extension. In the Ordovician Aprazível Formation were identified clastic dykes, coherent with a NW-SEoriented extension. An E-W- to ENE-WSW-oriented paleostress field acting from the Late Ordovician generated transpressive structures along certain ENE-WSW-fault segments, related with the mild inversion of the basin. This event is represented by conic drag folds in the Pacujá Formation related to the inversion of normal faults, with a strike-slip component. In the Parapuí Formation, this event might have determined the formation of ENE-WSWoriented veins with right-lateral strike-slip component and sigmoidal en échelon veins with the same orientation. Both in the Pacujá and Parapuí formations were identified a final event represented by E-W-oriented open fractures (N-S-oriented extension). These are correlatable to the paleostress field obtained for the NE-SW-oriented clastic dikes registered in the Ipú Formation of the Serra Grande Group (Silurian) of the Parnaiba Basin, as well as the conjugate hybrid joint arrangements measured in the same formation. The importance of the activity of the transverse faults, caused by the strike-slip kinematics along de Transbrasiliano fault system leads to consider that were these kinematics the trigger of the subsidence in the rift and subsequently the deformation during the inversionprocess. Therefore, in relation to the classification of the basin it is here considered that the Jaibaras is more closely related to a pull-apart basin than a pure rift.
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O território de trabalho dos carregadores piauienses no terminal da CEAGESP: modernização, mobilização e a migração / A study about the labor mobility in its different forms within the modernization process in São Paulo (Brazil)Sueli de Castro Gomes 20 August 2007 (has links)
O objeto da pesquisa é o estudo da mobilidade do trabalho em suas diferentes formas no processo de modernização, no qual a rede social aparece como um produto e suporte de desencadeamento. Para tal, estudamos a migração de nordestinos para a metrópole de São Paulo e em especial uma grande rede social de piauienses. Esse último grupo de migrantes nordestinos vai se inserir no mundo do trabalho na condição de carregadores no terminal de abastecimento da Grande São Paulo. Assim, esses nordestinos demarcam a sua territorialidade, expressa na relação de trabalho, na sua origem e na sua residência. A Companhia de Entrepostos e Armazéns Gerais do Estado de São Paulo - CEAGESP - possui entre outros equipamentos um entreposto terminal de produtos hortifrutigranjeiros e pescado. Este entreposto está instalado desde 1966 na Vila Leopoldina, localizado na Zona Oeste da cidade de São Paulo. Ele é um grande mercado de trabalho, em que a mobilidade do trabalho está materializada sob diversas formas ocupação tanto na área interna, como no seu entorno. As formas de trabalho desse Mercado estão inseridos nos dois circuitos da economia urbana. / This research aims at studying the labor mobility in its different forms within the modernization process, in which the social network appears as its product and also as a ground for its development. Thus, we exam the migration of Brazilian Northeastern people to the city of São Paulo, more specifically those from the State of Piauí. Members of this group tend to introduce themselves in the labor market in the condition of carriers in the São Paulo metropolitan supplying terminal, known as CEAGESP. By that, these migrants define their territoriality, expressed in the labor relationships they establish in their origin places as well as in their local residences. The State of São Paulo General Mart and Warehouse Company - CEAGESP - has among other equipments a commercialization terminal of vegetables, fruits, and fish and poultry products. This mart has been installed at Vila Leopoldina since 1966, located in the West Zone of the city of São Paulo. Also, it constitutes an immense \"labor market\", where the labor mobility is materialized under various occupation forms, be it in its internal area or in its surroundings. The labor forms of this market are inserted in both the urban economy circuits.
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Field Observations and Novel Methodologies for Carbon System Assessments in Coastal WatersYang, Bo 16 September 2015 (has links)
Coastal zones receive massive terrestrial inputs of nutrients and organic matter, and play an important role in biogeochemical cycles. The interactions of river inputs, ocean currents, atmospheric exchanges, anthropogenic influences, and biologically active ecosystems make CO2 system studies in coastal waters highly challenging. This work focuses on improving our understanding of the CO2 system in coastal waters through (1) development of a new methodology for measurements of CO2 system parameters in the field; (2) observations of large spatial and temporal CO2 system variations in coastal waters; and (3) characterization of the influence of organics on CO2 system behavior in coastal waters.
A novel portable light-emitting-diode (LED) photometer was developed to provide low-cost seawater pH measurements in the field. With meta cresol purple (mCP) as the indicator, the photometer produces pHT measurements within ± 0.01 units of state-of-the-art spectrophotometric measurements (7.6 ≤ pH ≤ 8.2, 30 ≤ S ≤ 36.2, and 15 oC ≤ t ≤ 30 oC). With a simple “do-it-yourself” (DIY) construction design, a hundredfold reduction in cost relative to benchtop spectrophotometric systems, and routine calibration-free operation in the field, the DIY photometer is an ideal replacement for pH test strips or consumer-level potentiometric probes. Applications of special interest include education, citizen science, coastal zone monitoring, and aquaculture and aquarium management.
Subannual variability of total alkalinity (TA) distributions in the northeastern Gulf of Mexico (GOM) was examined through the use of TA data from ship-based water sampling, historical records of riverine TA, and contemporaneous model output of surface currents and salinity. Variability of TA observed in the upper 150 m of the GOM water column was primarily controlled by subannual variations in the extent of mixing between seawater and river water. A transition in TA distribution patterns between the river-dominated northern margin (near the Mississippi–Atchafalaya River System) and the ocean current-dominated eastern margin (West Florida Shelf) was observed. A riverine alkalinity input index was developed to highlight riverine TA contributions.
Contributions of organic alkalinity (Org-Alk) to TA were investigated in coastal waters from three different environments (estuary, urban, mangrove) and offshore sites in the Gulf of Mexico. The difference in alkalinity (∆TA) between TA measured by direct titration (TAmeas) and calculated (TAcal) from observations of DIC and pH was used as an estimate of Org-Alk. Average values of ∆TA were 0.1 ± 5.0 µmol kg-1 at coastal sample sites outside the Mississippi-Atchafalaya River Estuary (n = 17), 1.9 ± 5.2 µmol kg-1 in offshore waters (n = 14) in the northern Gulf of Mexico, 33.6 ± 18.0 µmol kg-1 in the Suwannee River Estuary (n = 17), and 16.0 ± 25.4 µmol kg-1 in sites that included Tampa Bay, the Caloosahatchee River, and the Ten Thousand Islands area (n = 55). In addition to Org-Alk assessments based on measurements of ∆TA, a novel two-step spectophotometric titration method was developed for the characterization of Org-Alk. Direct titrations showed substantial Org-Alk in coastal samples (n = 5), and the Org-Alk values obtained from the two-step titrations showed good agreement with results from ∆TA calculations. The spectrophotometric titration data were used in model fits to evaluate the dissociation constants (pKi) of the natural organic acids. The pKi of the organic acids were within the previously reported range for riverine fulvic acids.
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Mapping and Kinematic Structural Analysis of the Deep Creek Fault Zone, South Flank of the Uinta Mountains, Near Vernal, UtahHaddox, David A. 11 May 2005 (has links) (PDF)
The geology along the southern flank of the Uinta Mountains, located north of Vernal, Utah, has been mapped at the 7.5' scale within two quadrangles: the Dry Fork and Steinaker Reservoir Quadrangles. Ambiguities dealing with stratigraphy, structural geology, and geohazards are currently being addressed as a result of this and other mapping projects in the vicinity. The geologic units in the area range in age from Mississippian to Late Cretaceous and include Uinta-sourced Tertiary units. Brief unit descriptions are provided for each of the units exposed in the map area. The main structural influence on the rocks within the area is that of the Uinta Uplift and its southern bounding fault, the Uinta Basin Boundary thrust. Locally, the Deep Creek fault zone overprints and dissects the southernmost flank of the broad Uinta Anticline. Other smaller structurally complex areas and folds exist east of the Deep Creek fault zone. The Deep Creek fault zone is made up of a series of NW-SE trending faults, likely related to the South Flank fault zone. Many authors have inferred dip-slip movement along the South Flank fault zone, but have not supported these claims using kinematic data. Detailed mapping and kinematic data collected within the study area has produced a better understanding of the deformation history along the fault zones in question. The faults within the Deep Creek fault zone have steep, linear traces upon which both vertical dip-slip and very nearly strike-slip (left-lateral oblique-slip, mainly) movement has occurred. The faults of the Deep Creek fault zone are likely Paleocene in age. The data suggest a bimodal history of deformation which the principal stress field does not seem to be influenced by typical east-northeast-west-southwest Laramide orogenic far-field stresses. The creation and early history of these faults may have been due to localized stress fields related to activity of the underlying Uinta Basin Boundary thrust, or a later period of uplift, a possible accommodation zone between the western and eastern domes of the Uinta Mountain Range, a transfer zone between the Uinta Basin Boundary thrust and the Asphalt Ridge fault, or a combination of these.
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Utilizing Climate Change Refugia For Climate Change Adaptation And Management In The NortheastWisner, Sara A 21 March 2022 (has links)
To account for the effects of climate change, management plans in the northeast need to incorporate climate adaptation. Conserving climate change refugia is one adaptation strategy. Climate change refugia are areas buffered by climate change that enable the persistence of valued physical, ecological, and cultural resources; preserving these areas could be a potential adaptation strategy. Using a translational ecology approach where researchers and managers from the National Park Service, US Geological Survey, the University of Massachusetts, and elsewhere worked together, we focused on identifying refugia for tree, herbaceous plant, mammal, and bird species in order to prioritize them for conservation action. Results predict shifts in distribution of habitats and species due to climate change, identifying areas to prioritize for invasive species treatment and other management actions. This study highlights priorities for future monitoring and data analysis, providing a model that can be replicated in other regions and motivate future research.
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Urban Park Co-Design: Empowering Future Female Retirees to Refocus Their LivesWu, Yifei 24 May 2023 (has links)
No description available.
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A Description of the American College Fraternity System at Selective, Private Colleges and Universities in the Northeast as Depicted by the Primary Administrative Contact, 1990-1991Chase, Ted Hunter 12 1900 (has links)
The purpose of the study was to gather sufficient data from a campus questionnaire and subsequent follow-up interview with the primary college administrators within the target population to accurately describe conditions of the fraternity systems on those campuses. The population for this study consisted of selective, small, private colleges and universities in the Northeast and Middle Atlantic region of the country. The target population of twenty-six colleges and universities was identified from the respondents to the campus questionnaire and included schools from the states of Maine, New Hampshire, New York, Massachusetts, Connecticut, and Pennsylvania.
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High resolution dinoflagellate cyst sedimentary records of past oceanographic and climatic history from the Northeastern Pacific over the last millenniumBringué, Manuel Alain 07 August 2015 (has links)
This thesis contributes to the development of dinoflagellate cysts as indicators of past environmental change in the Northeastern Pacific coastal ocean, and investigates past variations in sea-surface temperature, salinity and primary productivity encoded in dinoflagellate cyst sedimentary records from the Santa Barbara Basin (SBB, southern California) and Effingham Inlet (Vancouver Island, British Columbia) over the last millennium. The dinoflagellate cyst records extracted from the SBB and Effingham Inlet predominantly laminated sediments and analysed at sub-decadal resolutions, constitute some of the most detailed records of cyst-producing dinoflagellate populations in the world.
A two year-long sediment trap study from the SBB documents the seasonality in dinoflagellate cyst production for the first time on the Pacific coast of the United States. The study shows that dinoflagellate cyst data can be used as indicators of changes in sea-surface temperature and primary productivity associated with seasonal upwelling in the SBB. In particular, several dinoflagellate cyst taxa such as Brigantedinium spp. and Lingulodinium machaerophorum are identified as indicators of “active upwelling” (typically occurring in spring and early summer) and “relaxed upwelling” conditions (fall and early winter) at the site, respectively.
Analysis of a dinoflagellate cyst record from the SBB spanning the last ~260 years at biannual resolution documents the response of cyst-producing dinoflagellates to instrumentally-measured warming during the 20th century, and reveals decadal scale variations in primary productivity at the site that are coherent with phases of the Pacific Decadal Oscillation (PDO). The cyst assemblages are dominated by cysts produced by heterotrophic dinoflagellates (in particular Brigantedinium spp.), but the turn of the 20th century is marked by an abrupt increase in concentrations of L. machaerophorum and Spiniferites ramosus, two cyst taxa of autotrophic affinity. Their increasing abundances during the 20th century are interpreted to reflect warmer conditions and possibly stronger stratification during summer and fall. The dinoflagellate cyst data suggest a warming pulse in the early 1900s and provide further evidence that persistently warmer and/or more stratified conditions were established by the late 1920s.
The dinoflagellate cyst record from Effingham Inlet, spanning the last millennium, is characterized by the proportionally equal contribution of cysts produced by autotrophic and heterotrophic dinoflagellates in most samples. The cyst data indicate variations in sea-surface temperature, salinity and primary productivity that are associated with local expressions of the Medieval Climate Anomaly (from the base of the record to ~1230), the Little Ice Age (from ~1230 to ~1900) and warming during the second half of the 20th century.
Both dinoflagellate cyst records reveal that since the beginning (in the SBB) and mid-20th century (in Effingham Inlet), autotrophic dinoflagellates contribute to a greater portion of the primary production in the region, whereas heterotrophic dinoflagellates, as indicators of diatom populations, decline. Variability in the dinoflagellate cyst data is coherent at both sites and suggest a reduced expression of decadal scale variability associated with the PDO during the 19th century. / Graduate / 0416 / 0427 / mbringue@uvic.ca
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