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Surface and subsurface structures of the western Valley and Ridge in Tennessee and geometry and kinematics that permit reconstruction of the Tennessee salient, southern AppalachiansWhisner, Jennifer Kathleen 01 August 2010 (has links)
The southern and central Appalachian foreland fold-thrust belt comprises a series of orogen -scale curves that extend from Alabama to New York. One of these is the Tennessee salient, a foreland-convex curve that extends from Cartersville, Georgia, to Roanoke, Virginia. Development of a kinematic model for deformation in the salient has been hindered by a paucity of penetrative deformation in this generally low temperature, low volume-loss portion of the orogen.
Industry seismic reflection lines provide greater resolution of subsurface geometry of both the basement surface and the overlying fold-thrust belt, confirming some previous interpretations and changing others. A series of cross sections based on the seismic reflection data incorporates the improved understanding of basement geometry, as well as new interpretations of fold-thrust belt structures such as a sub-thrust detachment fold along the western margin of the Valley and Ridge, a smaller detachment fold along the Cumberland Escarpment, and a duplex below the Knoxville sheet in southeastern Tennessee.
The cross sections, combined with recently published analyses of calcite twin strain and paleomagnetic data around the salient, provide sufficient data to develop a new palinspastic reconstruction method and to propose a kinematic model for development of the salient. The basis of the reconstruction method is, in areas where the front of the indenter is oriented oblique to transport, the maximum shortening direction and particle displacement paths are also oblique to the bulk transport direction. Cross sections, kinematic indicators, and palinspastic reconstructions suggest that the Tennessee salient is a primary arc formed by a combination of uniform displacement in a single direction and transport-parallel simple shear (plane strain), that most major faults formed initially curved in front of the irregularly shaped Blue Ridge-Inner Piedmont indenter, and that transport in the fold-thrust belt may have occurred by plan view movement on networks of minor faults, which permitted forelandward propagation of the curved faults without significant rotation. Although the technique does not provide a unique solution, the resulting palinspastic restoration is kinematically admissible and geometrically reasonable. So, it may improve palinspastic restorations of facies in basins with no vertical axis rotations and minimal penetrative strain. Attachments are in PDF format and may be opened with Adobe Reader™.
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Geological Evolution of the Supracrustal Palaeoproterozoic Hamrånge Group: A Svecofennian Case StudyOgenhall, Erik January 2010 (has links)
The work presented in this thesis utilizes several geological methods to investigate the origin and evolution of the supracrustal rocks in the Palaeoproterozoic Hamrånge Group (HG) in the south-central Swedish Svecofennian. The first paper is based on whole-rock geochemistry to show the plate tectonic setting of volcanic rocks within the HG. This indicates that the environment was probably an oceanic volcanic arc. Geochronology, used in paper two, shows that the volcanism was active at 1888±6 Ma and that the sediments forming the stratigraphically overlying quartzite were deposited after 1855±10 Ma, with provenance ages overlapping both the volcanic rocks and the 1.86-1.84 Ga continental margin Ljusdal granitoids. In the third paper, thermobarometry was applied to samples from the HG, the migmatitic Ockelbo sub-domain to the south, and the 1.81 Ga Hagsta Gneiss Zone (HGZ) that separate these two units. The results show distinct differences in the metamorphic conditions that have affected the HG and the Ockelbo sub-domain, supporting previous interpretations that the HGZ is an important crustal structure, possibly a terrane or domain boundary. Paper four deals with the structural geology of the Hamrånge area. The study shows that the volcanic rocks and the underlying mica schist have been subjected to three deformation episodes (D1-D3), while the uppermost quartzite was most likely only affected by D2 and D3. While structures related to D1 are rarely seen, D2 resulted in a penetrative foliation, strong lineations and NW-vergent folding and thrusting. D3 is a result of a N-S compression that formed regional E-W folds and steep, ca. NW-SE shear zones, e.g. the HGZ. The results presented in this thesis, integrated with previously published data, outline a model for the geological evolution of the Hamrånge area: At 1.89 Ga a volcanic arc formed that subsequently collided with a continental margin resulting in the first deformation episode, D1, and probably a metamorphic event. This was possibly followed by an extensional period, after 1855±10 Ma, forming a basin that accumulated sediments later to form the quartzite stratigraphically on top of the volcanic rocks. The second deformation episode, D2, formed a fold-thrust belt when the supracrustal HG was thrusted to the NW, on top of the 1.86-1-84 Ga Ljusdal Domain. Flattening and a second metamorphic period followed this thickening of the crust. The last ductile deformation, D3, caused by regional tectonic forces, resulted in F3-folds that matured into ca. 1.8 Ga large-scale, steep shear zones transecting the Fennoscandian Shield.
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Analysis of the expression of INSR and FOX Genes in Celiac DiseaseHagos, Daniel Yemane January 2012 (has links)
Celiac disease (CD) is a common heritable immune related disorder where chronic inflammationof the small intestine is induced by the ingestion of gluten. The immune response leads to theinflammation and flattening of intestinal mucosa due to the damaged villi and thus results indefects in the absorption of nutrients. This defect can affect any organ or body system and exposeto the risk of lifelong complications such as cancer, autoimmune diseases and other complexdiseases. Now a day, celiac disease is becoming one of the well-studied models of complexdisorders.The PI3K- FOX signaling pathway is activated by many regulators and growth factors and playsa key role in cell cycle. Two components of this pathway, INSR and FOX, play crucial roles indiverse aspects of embryogenesis from the initial tissue genesis up to organ formation. INSR andFOX take part in development, differentiation, proliferation, apoptosis and stress resistance aswell as metabolism. SNP´s could affect the expression of neighboring genes. These SNP´s areshown to be as eQTLs, genomic loci that regulate the expression of genes. The aim of this studywas to detect and quantitate the expression of INSR and certain FOX genes in celiac disease.Quantitative real time PCR (QPCR) was used to analyze the expression of INSR, FOXO1,FOXO4 and FOXD3 genes in 38 celiac cases and 50 control samples. Three reference genesACTB, EPCAM and PGK1 were tested for their expression stability and their average was used inthe normalization procedure. Gene expression results were analyzed using the ΔCt method. Theexpression of INSR, FOXO1, FOXO4 and FOXD3 were described as their fold change in CDcompared to normal non-celiac mucosa. Our results indicated that FOXO4 and INSR wereexpressed less by 0.60 fold and FOXO1 was expressed less by 0.23 fold in CD samples. Theresults are preliminary and further studies will be needed to confirm if these findings are a resultof the intestinal inflammation in CD or if these genes are partly driving the disease itself.
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Experimental Study of the Microstructural Evolution of Chemical Vapor Deposited (CVD) Nickel upon AnnealingChichi, Chen 23 August 2011 (has links)
The effect of annealing conditions on the microstructure evolution of CVD nickel was investigated systematically in the present study by differential scanning calorimetry, optical microscopy and transmission electron microscopy (TEM), upon both ex-situ and in-situ annealing. TEM observation revealed the as-deposited CVD nickel possessed a bi-modal grain structure, with large columnar grains embedded in nanocrystalline matrix. Ultrafine and nano growth twins were present as well as multiply twinned grains with five-fold symmetry. Microstructure observation upon annealing showed that grain growth did not occur until annealing at 400ºC. Detwinning was observed at 400ºC and higher temperatures. The ultrafine and nano twins tended to transform into dislocation cell structures and this phenomenon was driven by the excess free energy associated with the high density of grown-in twin boundaries. The five-fold twinned grains were found to be thermally stable up to 600ºC. The hardness was observed to decrease with increasing annealing temperature.
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Experimental Study of the Microstructural Evolution of Chemical Vapor Deposited (CVD) Nickel upon AnnealingChichi, Chen 23 August 2011 (has links)
The effect of annealing conditions on the microstructure evolution of CVD nickel was investigated systematically in the present study by differential scanning calorimetry, optical microscopy and transmission electron microscopy (TEM), upon both ex-situ and in-situ annealing. TEM observation revealed the as-deposited CVD nickel possessed a bi-modal grain structure, with large columnar grains embedded in nanocrystalline matrix. Ultrafine and nano growth twins were present as well as multiply twinned grains with five-fold symmetry. Microstructure observation upon annealing showed that grain growth did not occur until annealing at 400ºC. Detwinning was observed at 400ºC and higher temperatures. The ultrafine and nano twins tended to transform into dislocation cell structures and this phenomenon was driven by the excess free energy associated with the high density of grown-in twin boundaries. The five-fold twinned grains were found to be thermally stable up to 600ºC. The hardness was observed to decrease with increasing annealing temperature.
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The Ten Stone Ranges Structural Complex of the central Mackenzie Mountains fold-and-thrust belt: a structural analysis with implications on the Plateau Fault and regional detachment levelMacDonald, Justin January 2009 (has links)
The Cordilleran Orogen affected majority of the western margin of ancient continental North America in the Cretaceous, which is well recorded in the Foreland Belt. The Mackenzie Mountains fold-and-thrust belt is located primarily in the westernmost Northwest Territories and easternmost Yukon Territory in northern Canada. The mountains are often described as the northern extension of the Rocky Mountains to the south which are one of the world’s best examples of a thin-skinned fold-and-thrust belt. Within the Mackenzie Mountains, Neo-Proterozoic through Cretaceous sedimentary rocks record the Laramide aged deformation, with a range of structures that vary in size and complexity. Previous mapping by the Geological Survey of Canada produced a series of reconnaissance maps that are still in use today, many of which are available in only black and white.
This study is focused on a part of the 1:250 000 scale NTS 106A Mount Eduni map sheet from Geological Survey of Canada reconnaissance mapping in 1974. The study involved re-mapping a large panel at 1:50 000 scale to better understand the structural geometry, regional shortening and the depth of the underlying detachment level. Through systematic geologic mapping and structural analyses, this study presents a balanced regional cross-section, numerous serial cross-sections and a detailed geologic map of the study area, the Ten Stone Ranges Structural Complex.
The serial cross-sections were used to define the geometry of the Cache Lake Fold, a large fault-bend-fold system that involves a folded thrust fault and complicated subsurface geometry. In addition to this, the sections confirmed that the TSRSC is a transfer zone whereby a series of thrust faults and décollement folds are responsible for much of the displacement and shortening in the Mount Eduni map sheet. The balanced regional cross-section was constructed across a number of key structural elements, in particular the Plateau Fault, a regional structure with a > 250 kilometer strike length and the subject of much debate as to its geometry. In addition to this structure, the cross-section transects the Cache Lake Fold and the Shattered Range Anticline, a regional box shaped anticline that was used for a “depth to detachment” calculation. By examining the regional detachment level estimated from the balanced cross-section and calculating the detachment depth using the Shattered Range Anticline the detachment depth was found to be – 11.3 kilometers below the current erosional level.
This study is the first structural analyses of the Mount Eduni map sheet, particularly the Ten Stone Ranges Structural Complex, and has resulted in an estimate of the detachment depth for the area, a shortening estimate of > 7 kilometers across the 50 kilometer line of section and a displacement estimate for the Plateau Thrust of > 20 kilometers.
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The Ten Stone Ranges Structural Complex of the central Mackenzie Mountains fold-and-thrust belt: a structural analysis with implications on the Plateau Fault and regional detachment levelMacDonald, Justin January 2009 (has links)
The Cordilleran Orogen affected majority of the western margin of ancient continental North America in the Cretaceous, which is well recorded in the Foreland Belt. The Mackenzie Mountains fold-and-thrust belt is located primarily in the westernmost Northwest Territories and easternmost Yukon Territory in northern Canada. The mountains are often described as the northern extension of the Rocky Mountains to the south which are one of the world’s best examples of a thin-skinned fold-and-thrust belt. Within the Mackenzie Mountains, Neo-Proterozoic through Cretaceous sedimentary rocks record the Laramide aged deformation, with a range of structures that vary in size and complexity. Previous mapping by the Geological Survey of Canada produced a series of reconnaissance maps that are still in use today, many of which are available in only black and white.
This study is focused on a part of the 1:250 000 scale NTS 106A Mount Eduni map sheet from Geological Survey of Canada reconnaissance mapping in 1974. The study involved re-mapping a large panel at 1:50 000 scale to better understand the structural geometry, regional shortening and the depth of the underlying detachment level. Through systematic geologic mapping and structural analyses, this study presents a balanced regional cross-section, numerous serial cross-sections and a detailed geologic map of the study area, the Ten Stone Ranges Structural Complex.
The serial cross-sections were used to define the geometry of the Cache Lake Fold, a large fault-bend-fold system that involves a folded thrust fault and complicated subsurface geometry. In addition to this, the sections confirmed that the TSRSC is a transfer zone whereby a series of thrust faults and décollement folds are responsible for much of the displacement and shortening in the Mount Eduni map sheet. The balanced regional cross-section was constructed across a number of key structural elements, in particular the Plateau Fault, a regional structure with a > 250 kilometer strike length and the subject of much debate as to its geometry. In addition to this structure, the cross-section transects the Cache Lake Fold and the Shattered Range Anticline, a regional box shaped anticline that was used for a “depth to detachment” calculation. By examining the regional detachment level estimated from the balanced cross-section and calculating the detachment depth using the Shattered Range Anticline the detachment depth was found to be – 11.3 kilometers below the current erosional level.
This study is the first structural analyses of the Mount Eduni map sheet, particularly the Ten Stone Ranges Structural Complex, and has resulted in an estimate of the detachment depth for the area, a shortening estimate of > 7 kilometers across the 50 kilometer line of section and a displacement estimate for the Plateau Thrust of > 20 kilometers.
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Fold-and-thrust belt deformation of the Hongliuhe Group: a Permian tectonic closure record of the Central Asian Orogenic Belt, NW ChinaCleven, Nathan January 2011 (has links)
The Early Permian strata of the Hongliuhe Group, NW China, experienced a thin-skinned fold-and-thrust belt style of deformation that recorded the final stages of amalgamation of the Beishan orogenic collage, a part of the Central Asian Orogenic Belt. The Hongliuhe Group was syn-orogenically deposited on an undetermined foreland, with the Mazongshan arc terrane acting as the hinterland. In this study results from detailed mapping combined with a regional analysis elucidate involvement of a northward-dipping subduction system with the collision.
Well-preserved fold-and-thrust belt style deformation mapped in the upper stratigraphy of the Hongliuhe Group exhibits dominantly south-southeast verging structure, including shear folding, low-angle thrust ramping, imbrication and duplexing. Restoration of a portion of a mapped outcrop-scale cross-section estimates the accommodation of a minimum of 24% shortening. Lower stratigraphy shows discrete, steeper, north-over-south dip-slip ductile shear zones that bound packages of less deformed Hongliuhe Group strata. Fault displacement is considered to have been prolonged enough to juxtapose basal formations in northerly hangingwalls against upper formations in southerly footwalls. Faulting is closely associated with the creation of large-scale brittle-ductile eye-fold structures that are postulated to be sheath folds. The most examined and mapped structure, 16km wide, is a synclinal structure with axes plunging steeply towards its center. The ellipticity of the exposed bedding traces increases towards the center of the eye-fold, implying a structural relationship with metamorphic shear zones. Except for large-scale folding, the bulk of its strata remain relatively undeformed and have preserved primary soft-sediment deformation structures indicating younging towards the center on both limbs of the synclinal structure.
Stratigraphic reconstruction of the Hongliuhe Group that considers the significant faulting shows that the Group's basal conglomerates unconformably overlie a Late-Carboniferous volcanic assemblage. The clast lithotypes of the conglomeratic successions change from polymictic metamorphic rocks at the base to monomictic granitoid clasts mid-section, showing the gradual unroofing sequence of the provenance. The stratigraphic reconstruction shows a general fining upward sequence, transitioning from terrestrial to nearshore marine depositional environments that, and in conjunction with the conglomeratic successions, suggests that the tectonic setting for deposition of the Hongliuhe Group is a foreland basin. Considering the deformation styles reported in this study, the Hongliuhe Group is interpreted to be a foreland fold-and-thrust belt.
Stratigraphic reconstruction of the Hongliuhe Group that considers the significant faulting shows that the Group’s basal conglomerates unconformably overlie a Late Carboniferous volcanic assemblage. The clast lithotypes of the conglomeratic successions change from polymictic metamorphic rocks at the base to monomictic granitoid mid-section, showing the gradual unroofing sequence of the provenance. The stratigraphic reconstruction shows a general fining upward sequence through nearshore depositional environments that, and in conjunction with the conglomeratic successions, give interpretation that the tectonic setting for deposition of the Hongliuhe Group is a foreland basin. Considering the deformation styles reported in this study the Hongliuhe Group is interpreted to be a foreland fold-and-thrust belt.
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Telomere Protection and Maintenance in Arabidopsis thalianaSong, Xiangyu 2010 May 1900 (has links)
Telomeres are the physical ends of linear chromosomes in eukaryotes. Telomeres
not only protect chromosome ends from being recognized as double-strand breaks but
also maintain the chromosome terminal sequences. These processes involve a number
of telomere-related proteins. A major challenge in the field is to elucidate the full
constitution of telomere-associated proteins and to understand how different protein
complexes are regulated at chromosome termini.
Here, I report the identification and characterization of STN1 (Suppressor of cdc
thirteen, 1), CTC1 (Conserved Telomere maintenance Component 1) and TEN1
(Telomeric pathways in association with Stn1, 1) in Arabidopsis. CTC1/STN1/TEN1
(CST) forms a trimeric complex that specifically associates with telomeres. Loss of any
component of the CST induces catastrophic telomere loss, disrupted telomere end
architecture, and massive chromosome end-to-end fusions. Thus, CST plays an
essential role in chromosome end protection. I also show that CST function at
telomeres is independent of a previously characterized capping complex KU70/KU80,
and that ATR is responsible for a checkpoint response in plants lacking CTC1/STN1.
Additionally, I present data showing that Arabidopsis POT1a (Protection Of
Telomere 1, a) has evolved as a telomerase recruitment factor. Unlike POT1 in other eukaryotes which binds and protects ss telomeric DNA, AtPOT1a interacts with
telomerase RNA (TER). Based on an evolutionary analysis, we found that the POT1a
lineage is under positive selection in the Brassicaceae family in which Arabidopsis
belongs. Mutations of two positive selection sites significantly reduce POT1a?s activity in
vivo. These data suggest POT1a is under pressure to evolve from a telomeric DNA
binding protein to a TER binding protein. I also discovered that POT1a interacts with the
novel telomere capping protein CTC1 in vitro and in vivo. Thus, I hypothesize that
POT1a acts as a telomerase recruitment factor linking this enzyme to the chromosome
termini via interacting with TER and CTC1. Finally, I dissected the functional domains of
POT1a and demonstrated that both the N-terminus and the C-terminus of POT1a are
required for its function in vivo.
In summary, my work has uncovered several new and essential telomereassociated
proteins that provide new insight into mechanisms of chromosome end
protection and maintenance.
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Effects of dietary supplemental nucleotides on the health of juvenile grouper Epinephelus coioidesLiao, Ru-chun 13 February 2004 (has links)
Dietary effects of a nucleotide mixture that contained AMP¡BGMP¡BCMP¡BUMP and IMP in equivalent amount were evaluated in 4 supplemental levels of 0, 0.05, 0.2, and 0.4 g/100g diet. Weight gain (519-616%) of juvenile groupers fed for 14 weeks with the test diets was not significantly affected by the supplements. Serum concentrations of total protein, albumin, and cholesterol, A/G ratio and activities of AST were also not significantly affected. Serum total bilirubin concentration in the 0.4 g/100g group was significantly higher than the 0 or 0.05 g/100g group. Head-kidney macrophage phagocytosis and intracellular superoxide anion production as well as serum lysozyme activity were also not different among treatments. Histological sections of fish gut indicated that villous heights of intestinal fold were significantly greater in the 0.2g/100g group than the 0.4 g/100g group, muscle layer thickness, in contrast, was not affected. When challenged with Photobacterium damsela subsp. damselae after fed the test for 3 weeks, relative percent survivals of the groupers were 87.8, 91.1, 90.0 and 94.4% (0, 0.05, 0.2, and 0.4 g/100g diet, respectively). The survivals were 74.5, 82.4, 86.3, and 85.3%, respectively when the feeding trial was extended to 18 weeks. The results show that a diet containg 38% protein and asupplemented with nucleotides at the tested levels was not effective in promoting growth, but was moderately effective in enhancing immune responses and pathogen resistance of juvenile grouper.
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