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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.
21

Study Of Modeling Of Water Saturation In Archie And Non-archie Porous Media

Dalkhaa, Chantsalmaa 01 August 2005 (has links) (PDF)
The aim of this thesis is to study water saturation models available in the literature and to apply a proper one to a real field case. Archie equation is the most well-known water saturation model. However, it is formulated on some assumptions and is applicable to only clean sands. Archie equation cannot be used for shaly formation. There are many shaly water saturation models that account for shale effect for water saturation estimation. In this study, 3 wells, namely Well-01, Well-02 and Well-03 are studied. These wells lie in a fractured carbonate reservoir located in Southeastern part of Turkey. From well log recordings, the production formation is seen almost clean. In other words, the shale amount of the formation is so small that it can be neglected. Thus, to calculate the water saturation in those wells, the well-known Archie water saturation equation is used. Since the formation is fractured carbonate, the cementation factor (m ) and saturation exponent (n ) of conventional value of 2 each cannot be used for the water saturation calculation. Instead, these parameters are obtained from generalized crossplot of log-derived porosity and resistivity technique. Finally, each well is divided into zones using porosity data. Zonation is conducted based on statistical method, ANOVA (analysis of variance). Well-01 and Well-02 are both divided into two zones. On the other hand, the statistical method was initially divided Well-03 into three zones. However, Well-03 is better described as a whole zone, depending on the geological analysis and engineering judgment. After the zonation, the zones are correlated from well to well. The water saturations in significantly correlated zones are examined. Also, using the same statistical method, the water saturation zones are identified. However, these zones do not coincide with the porosity zones. This difference is attributed to pore size distribution and wettability which affect saturation distribution.
22

The distribution and zonation of intertidal organisms of rocky coasts in south eastern Australia

King, Robert John Unknown Date (has links) (PDF)
The intertidal flora and fauna of S.E. Australia (Robe, South Australia to S. New South Wales, including Tasmania) is described in terms of its horizontal and vertical distribution. A detailed account of intertidal zonation, on the central Victorian coast and Bass Strait islands, is included. Environmental features are discussed and sea temperature data for Pt. Lonsdale is presented. / Analysis of the marine flora in S.E. Australia suggests that the concept of separate biogeographic provinces in this region is invalid and the flora is best interpreted as a continuum.
23

The distribution and zonation of intertidal organisms of rocky coasts in south eastern Australia

King, R. J. January 1972 (has links)
Thesis (Ph. D.)--University of Melbourne, 1972. / Includes bibliographical references.
24

Sinice dostřikové zóny pobřeží ostrovů Veruda a Ugljan, Chorvatsko / Cyanobacteria in the splash zone of the Veruda and Ugljan islands, Croatia

VONDRÁŠKOVÁ, Alžběta January 2014 (has links)
Cyanobacterial communities of the splash zone of two Croatian islands, Veruda and Ugljan, were surveyed on 16 localities both in horizontal and vertical directions. In 336 samples 42 cyanobacterial species, 1 green alga, and 1 red alga were found. On both islands Hyella spp. and Gloeocapsopsis crepidinum dominated. Solentia spp., Kyrtuthrix dalmatica, and Mastigocoleus testarum were also found frequently. According to statistical analyses 3 horizontal parts of the splash zone were shown to host different cyanobacterial communities. In the horizontal direction there were no statistical differences among sampling points; however, for uncovering the whole cyanobacterial diversity more samples from various distances are necessary. The species diversity and distribution were not dependent on the orientation of the locality toward cardinal points.
25

Sinice dostřikové zóny pobřeží ostrovů Veruda a Ugljan, Chorvatsko / Cyanobacteria in the splash zone of the Veruda and Ugljan islands, Croatia

VONDRÁŠKOVÁ, Alžběta January 2014 (has links)
Cyanobacterial communities of the splash zone of two Croatian islands, Veruda and Ugljan, were surveyed on 16 localities both in horizontal and vertical directions. In 336 samples 42 cyanobacterial species, 1 green alga, and 1 red alga were found. On both islands Hyella spp. and Gloeocapsopsis crepidinum dominated. Solentia spp., Kyrtuthrix dalmatica, and Mastigocoleus testarum were also found frequently. According to statistical analyses 3 horizontal parts of the splash zone were shown to host different cyanobacterial communities. In the horizontal direction there were no statistical differences among sampling points; however, for uncovering the whole cyanobacterial diversity more samples from various distances are necessary. The species diversity and distribution were not dependent on the orientation of the locality toward cardinal points.
26

Zoneamento agroclimático da flor tropical Alpinia purpurata no Estado de Pernambuco

MEDEIROS, Sérgio Ricardo Rodrigues de 03 October 2007 (has links)
Submitted by (lucia.rodrigues@ufrpe.br) on 2016-10-13T14:03:38Z No. of bitstreams: 1 Sergio Ricardo Medeiros.pdf: 1726192 bytes, checksum: f51d3d7982bf95eb85845ad7c3cf1c60 (MD5) / Made available in DSpace on 2016-10-13T14:03:38Z (GMT). No. of bitstreams: 1 Sergio Ricardo Medeiros.pdf: 1726192 bytes, checksum: f51d3d7982bf95eb85845ad7c3cf1c60 (MD5) Previous issue date: 2007-10-03 / For the agroclimatic zonation of the Alpinia purpurata the climatic data of 123 localities, being 69 with a period above 30 years and 54 below 30 years has been used, thus getting a better representation of the data in the State. The climatic data of the average temperatures of air and rainfall, of which the water balance according to Thornthwaite & Mather (1955) has been calculated. The cities of Igarassú, Primavera, Goiana and São Lourenço da Mata, have been chosen to be climatic representatives, as they are the producers of the species in Pernambuco. Having the data of the water balance in hand, minimum and maximum temperatures of air, the indexes of thermal and hydric limit in relation to the requirements of the species in the representative cities has been esteemed, and thus these indexes have been surpassed for all the State. In accordance with the Pernambuco study it presented 6 localities with full aptitude, 16 with regular aptitude and 111 with inaptitude the species. / Para o zoneamento agroclimático da Alpinia purpurata foram utilizados os dados climáticos de 123 localidades, sendo 69 com uma série acima de 30 anos de observações e 54 abaixo de 30 anos de observações, obtendo assim uma melhor representatividade de dados no Estado. Os dados climáticos de temperaturas médias do ar e precipitação pluviométrica, dos quais foram calculados os balanços hídricos segundo Thornthwaite & Mather (1955). Os municípios de Igarassú, Primavera, Goiana e São Lourenço da Mata, foram escolhidos para serem representativos climatológicos, pois são os produtores da espécie em Pernambuco. De posse dos dados dos balanços hídricos, temperaturas mínimas e máximas do ar, foram estimados os índices de limite térmico e hídrico em relação às exigências da espécie nos municípios representativos, e assim esses índices foram extrapolados para todo o Estado. De acordo com o estudo Pernambuco apresentaram 6 localidades com aptidão plena, 16 com aptidão regular e 111 com inaptidão a espécie.
27

The structure of experimental clastic-substrate marine communities

Evans, Wayne Aloysius 01 January 1976 (has links)
It is hypothesized that difference between containers and between sediments will produce structural differences in the resulting communities by intensifying competition for resources, and by excluding certain classes of predators. It is also hypothesized that the level of the effect of container, substrate, and time on community structures will be dependent on tidal level. Paine (1969) and Dayton (1972) have demonstrated that the structure of some communities is largely determined by the effects of foundation, or keystone, species. It is suggested that the structure of classic-substrate communities may be determined similarly.
28

Effects of Intertidal Position on the Capacity for Anaerobic Metabolism and Thermal Stress Response in the Common Acorn Barnacle, Balanus glandula

Anderson, Kyra 01 February 2022 (has links) (PDF)
Intertidal habitats are characterized by dynamic, tidally-driven fluctuations in abiotic and biotic factors. Many of the environmental stressors that vary across the intertidal (e.g., temperature, oxygen, food availability, predation pressure) are strong drivers of metabolic rate in ectotherms. As such, we predicted that there may be pronounced differences in the metabolic and stress physiology of conspecific sessile invertebrates occupying at different relative tidal heights. The common acorn barnacle Balanus glandula represents an ideal model organism in which to investigate the possibility of tidal height-dependent physiological differences, owing to their wide distribution in the intertidal zone and their eurytolerant nature. In the first chapter of my thesis, we investigate the hypothesis that B. glandula anchored in the low intertidal have a greater capacity for anaerobic metabolism than conspecifics in the high intertidal, and that this is due to increased predation pressure during submersion. Further, we explore the temporal and spatial fidelity of certain tidal-height driven trends in lactate dehydrogenase activity previously observed in our lab (i.e., higher LDH activity in low intertidal barnacles; Horn et al., 2021), and attempt to identify environmental variables that drive plasticity in LDH activity. We found that, in general, there were higher densities of B. glandula and gastropod whelk predators in the low intertidal compared to the high intertidal, but follow-up studies in the lab revealed that opercular closure in B. glandula was induced by predator exposure (Acanthinucella spirata) for less than 24h. This time frame for shell closure is unlikely to result in internal hypoxia or enhance capacity for anaerobic metabolism. We were therefore not surprised to find that LDH activity in B. glandula was likewise not affected by predator exposures (48h) carried out in the lab. After failing to find an effect of predators on LDH activity in B. glandula, we attempted to replicate the previous finding that LDH activity was highest in low intertidal populations of B. glandula. We did this at the original location in San Luis Obispo Bay, CA as well as at three novel field sites and across seasons and years. While we did observe variation in LDH activity over time and between sites, we did not consistently observe the same trend in LDH activity whereby low intertidal barnacles had the highest activity. In response to these variable patterns, we attempted to identify what environmental parameters, other than predation, might be responsible for plasticity in LDH activity. Unfortunately, neither temperature nor emersion stress – the two variables we examined – had any significant an effect on LDH activity in B. glandula. These data suggest that there must be multiple, interacting stressors – including tidal position - that influence the anaerobic metabolic capacity of B. glandula. In the second chapter of my thesis, we went on to investigate how the response to thermal stress might differ between populations of B. glandula from different vertical heights in the intertidal zone. To this end, we assessed how aerial temperature stress affected oxygen consumption rates (MO2), superoxide dismutase (SOD) activity, and time to mortality in B. glandula collected from both low and high intertidal positions. We found that barnacles from the low intertidal showed a significant increase in MO2 with higher temperature, while MO2 was unaffected by temperature in B. glandula from the high intertidal. We also observed that SOD activity levels were higher in the high intertidal barnacles compared to the low intertidal barnacles, although neither group was increasing SOD activity under higher temperature. Finally, we observed significantly longer survival times during thermal stress in barnacles from the high intertidal zone (e.g., LT50 = 8.75 h vs 5 h at 33˚C for the high and low barnacles, respectively), although this advantage seemed to be lost with the addition of desiccation stress at these same temperatures. It is evident that life in highest reaches of the intertidal zones is physiologically challenging, and this has resulted in a population of B, glandula barnacles that are less sensitive to and better suited to tolerate temperature extremes than conspecifics in the lowest intertidal regions. Understanding how habitat variation may differentially impact the metabolic and thermal stress physiology of B. glandula is increasingly important as climate change progresses. This is particularly significant considering that organisms in the intertidal already reside within a relatively stressful environment and may be living closer to their thermal tolerance limits than animals from less extreme habitats.
29

The Preservation and Protection of Native Biodiversity in the Guadalupe Nipomo Dunes Complex

Whitaker, Lindsey M, Ritter, Matthew, Steinmaus, Scott J., Hall, Jonathan 01 August 2016 (has links) (PDF)
The Guadalupe Nipomo Dunes Complex (GNDC) is located within the California Floristic Province, a biodiversity hotspot characterized by high rates of endemism and exceptional loss of habitat. In 1980, the US Fish and Wildlife Service described the GNDC as, “the most unique and fragile ecosystem in the State of California,” and ranked it first on a list of 49 habitat areas needing state protection. It is the largest coastal dune area in California and it is one of the last remaining, relatively intact ecosystems of its type and size in the western United States. The growing recognition of species decline and the limited number of dollars allocated to conservation and restoration have led to development of new conservation planning software and conservation strategies. Marxan and Zonation were selected for this project due to their worldwide acceptance in biodiversity conservation planning as well as their specialization in identifying priority zones for conservation. This document describes the unique use of conservation planning software to select areas for resource allocation. It outlines the process of selecting conservation targets, the habitats and species important to overall health of an ecosystem, by using the expert involvement approach. Most importantly, this document outlines areas of high biodiversity that will later be used to allocate resources for the preservation and protection of biodiversity within the Guadalupe Nipomo Dunes Complex. Introduced species are the second-leading cause (after habitat degradation/loss), causing or contributing to the decline in species abundance and diversity. Ehrharta calycina Smith has become highly invasive in the coastal dune communities of Central and Southern California and currently holds a “high” CAL-IPC inventory rating, defined as a species with severe ecological impacts on physical processes, plant and animal communities and vegetation structure as well as reproductive biology and other attributes conducive to moderate to high rates of dispersal and establishment. Ehrharta calycina is a prolific seeder and stores its seeds annually in the soil, collecting a substantial seedbank. Little is known about E.calycina outside its native range, as its invasion into California coastal ecosystem is fairly recent. A field experiment in the Guadalupe Nipomo Dunes Complex assessed the contribution of seeds originating from the seedbank as compared to seeds from above ground either dropping from maternal plants or blown in from outside the plots to the establishment of new E. calycina cover. After a nine month perios, new E. calycina cover from both sources was not significantly different. Visible coverage of E. calycina began 77 days (November 24, 2015) after plot installation. After nine months of surveying, coverage reached 19% in the Seedbank Present treatment and 21% in the Seedbank Absent treatment. There was no significant effect associated with the slope and aspect of the experimental locations. This experiment will aid in management of this invasive species by educating land managers to focus on preventing current seed production of established individuals as those sources of seed were as important as those originating in the seedbank. Stimulating germination of seeds from the seedbank with a concomitant management strategy such as herbicide application or physical removal will likely be the most effective methods for dealing with seeds in the seedbank.
30

Sex-biased and xenobiotic-responsive long non-coding RNAs in mouse liver: sub-cellular localization, liver cell-type specificity, and knockdown by epigenetic reprogramming

Goldfarb, Christine Nykyforchyn 19 January 2021 (has links)
Long non-coding RNAs (lncRNAs) are key regulators of gene expression, playing crucial roles in biological processes across many species, tissues and diseases. The liver is a highly responsive organ in which large changes in gene expression are perpetuated by a myriad of internal and external stimuli; as such, the liver makes an ideal system in which to study lncRNAs. Global patterns of expression, maturation and localization were established for both lncRNA and protein-coding gene (PCG) transcripts across five subcellular compartments in male and female mouse liver, both with and without exposure to TCPOBOP, a direct agonist of the nuclear receptor CAR. In contrast to PCGs, lncRNAs showed very strong enrichment for tight chromatin binding, which increased the sensitivity for lncRNA detection and facilitated discovery of many novel sex-biased and xenobiotic-responsive lncRNAs. These findings helped identify candidate regulatory lncRNAs based on their co-localization within topologically associating domains, or their transcription divergent or antisense to PCGs associated with pathways linked to liver physiology and disease. The liver cell type-specific expression of lncRNAs and PCGs was assessed by single nucleus RNA-seq (snRNA-seq). Liver sexual dimorphism was largely restricted to hepatocyte populations, where many sex-biased genes exhibited zonated expression. Changes in lncRNA and PCG expression following exposure to endogenous hormones (growth hormone) and exogenous chemicals (TCPOBOP) was assessed, identifying cell cluster-specific perturbations to native sex-bias and hepatocyte zonation-dependent gene expression, and highlighting the interconnectedness between liver sexual dimorphism and zonation of the hepatic lobule at the single nuclei level. Finally, an in vivo method for epigenetic reprogramming of lncRNAs using a dual adeno-associated virus delivery system was utilized to knockdown two TCPOBOP-inducible lncRNAs in mouse liver. The knockdown phenotype of one of these lncRNAs, established by snRNA-seq, suggests it plays a functional role in regulating cholesterol metabolism and transport, triglyceride catabolism, and pyruvate metabolism in mouse liver. Together, these studies characterize hepatic lncRNA expression patterns, on both the sub-cellular and single cell levels, and present a strategy for interrogating the roles of specific lncRNAs in liver tissue in vivo. / 2023-01-18T00:00:00Z

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