Browsing by Subject "BMP"
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Item A New Method to Assess Best Management Practice Efficiency to Optimize Storm Water Management(2014-12-16) Tu, Min-chengFor TSS, TN, and TP, this study examined the relationship between BMP pollutant removal efficiency and environmental factors such as ratio of BMP/catchment area, dominant land use, ratio of the dominant land use/catchment area, slope, and BMP type, and derived optimal installation plans based on different criteria. A SWMM model was built for the Shoal Creek Watershed in Austin, Texas. Inverse modeling (i.e. fitting model to observation data) was used to calibrate the BMP removal efficiency. The relationship can then be derived by using multiple linear regression analysis with BMP removal efficiency as the response variable and the environmental factors as predictive variables. However, before inverse modeling can be applied, SWMM pollutant buildup and washoff parameters must be derived. A few types of land use were identified as main source of pollutant. The numerical distribution of the parameters suggested that the buildup and the washoff parameters are controlled by forces of different spatial scales. Also, the SWMM model simulated only direct runoff in order to simplify the calibration. Mean pollutant concentration in base flow is required to convert observed concentration to that in direct runoff. The Shoal Creek Watershed discharges into Lady Bird Lake, and changes of water quality in the lake during base flow dominant dates were used to estimate concentration in base flow from Shoal Creek Watershed. Water quality of the lake was determined by Landsat imagery. The equations predicting BMP removal efficiency based on environmental factors were analyzed to show the most efficient and least efficient type of BMP and the land use that BMPs will have the highest and lowest removal efficiency for TSS, TN, and TP. Two planning criteria were utilized for the optimal BMP plans and different time frames were considered. One criterion is goal concentrations in runoff, and the other is a combination of goal concentration and a budget constraint. For each criterion, the associated optimal plan showed an areal ratio between BMP types throughout different time frame. It was also found that the Shoal Creek Watershed needs more BMPs. Suggestions to the Environmental Criteria Manual of Austin were also made based on this study.Item BMPs Regulate the Oft Development via miRNAs(2014-08-04) Bai, YanCongenital heart diseases (CHD) are the leading cause of infant mortality and morbidity. Defects of the outflow tract (OFT) make up a large percentage of human CHD. In my study, I focused on the role of Bone morphogenetic protein (BMP) on heart development. I investigated Bmp signaling in OFT development using conditional knocking out Bmps, including Bmp2, -4 and -7. Deletion of Bmp4/7 in second heart field (SHF) results in persistent truncus arteriosus (PTA), which is caused by endothelial to mesenchyme transition (EMT) defect. I found that Vegfa (vascular endothelial growth factor a) is a downstream target of Bmp and miR-17-92. Repression of Vegfa in OFT is important for the proper onset of EMT at E10.5. Further exploration on Bmp2/4/7 mutation indicates that loss of Bmp signal disrupt the smooth muscle differentiation and maintenance. Similar with observations on Marfan syndrome mouse model, Bmp2/4/7 triple CKO embryos exhibited significant upregulation of Tgf-? signal activity. Alternation of SMC feature is likely due to the persistence of Isl-1 expression. Haploinsufficiency of Bmp4 triggered early onset of aorta aneurysm in Fbn-1^(C1039G/+) mice. These data indicate that Bmps not only play an important role in embryonic cardiogenesis, but also are critical for the cell fate differentiation and maintenance in adulthood.Item The cellular and molecular mechanisms underlying ventral midline patterning and morphogenesis in the amniote midbrain(2015-12) Brown, Charmaine Yvonne; Agarwala, Seema; Vokes, Steven; Eberhart, Johann; Ehrlich, Lauren; Gross, JeffThe floorplate (FP) is located at the ventral midline of the developing neural tube, and is involved in patterning and specification of ventral and dorsal cell fates. The FP has long been known to pattern ventral cell fates via secretion of Sonic Hedgehog (SHH). However, the mechanism by which the FP is specified is controversial due to species variations where SHH is differentially required for FP specification in fish and mouse. In Chapter 3, we show that, similar to the fish, the amniote anterior neural plate can be divided into medial (MFP) and lateral (LFP) subdivisions which differentially require SHH and FOXA2 for their specification, and that FOXA2, but not SHH, is sufficient to induce the entire midbrain FP pattern. In addition, we show that all three midbrain signaling centers are physically continuous and interconvertible, with their specification depending on SHH. Prior to the expression of SHH protein, the ventral midline undergoes a morphogenetic event called median hinge point (MHP) formation which buckles the flat neural plate and lifts the neural folds which ultimately fuse into a cylindrical neural tube. Previous studies in the lab have shown that Bone Morphogenetic Proteins (BMP) modulate HP formation. HP formation involves dynamic cell-shape changes, which result in HP cells becoming wedge-shaped. Multiple mechanisms (constriction of the adherens belt via cytoskeletal and junctional remodeling, and polarized endocytosis) have been proposed to explain this shape change. However, they do not explain how reduction in apical area can be achieved in the amniote neural plate where cells are bipolar and only slender processes contact the apical surface in non-mitotic cells. In Chapter 4, we develop an early electroporation technique which is used in Chapter 5 to visualize HP formation in real time as part of a novel 3D explant system. Our results suggest that BMP attenuation regulates cell cycle progression by increasing the duration of G1 and S phases, and causes a subset of cells to prematurely exit the cell cycle and undergo sub-apical G2-M transition, similar to what is seen in the MHP where there is reduced mitotic index and cells undergo mitosis sub-apically.Item Locating turfgrass production sites for removal of phosphorus in Erath County, Texas(Texas A&M University, 2004-09-30) Hanzlik, Jeremy EdwardThe North Bosque River watershed of central Texas hosts a large portion of diary production in the state. In recent years, the Texas Commission on Environmental Quality (TCEQ), formerly known as the Texas Natural Resource Conservation Commission (TNRCC), has applied a Total Maximum Daily Load Program for soluble phosphorus to the watershed. Best management practices (BMPs) are now necessary to remedy the issue of excess phosphorus. This thesis explores the application of GIS as an agricultural planning tool in support of a BMP for the region. The suggested BMP calls for the production of turfgrass sod using composted dairy manure; this sod is then transported at a profit from the watershed and provides an economically sustainable means to reduce the nutrient loading in the watershed. Using GIS, a geospatial database was developed with available data from government and institutional sources. As part of the development process, these sites were verified by field technicians and the results were combined in the GIS to refine the database. This database demonstrates the suitability of GIS as a tool for large-scale planning in agriculture.Item Mechanisms of Wnt8 function in zebrafish mesoderm patterning(Texas A&M University, 2006-08-16) Ramel, Marie-ChristineIn vertebrate embryonic development, correct specification of tissue fates along the dorsoventral (D/V) axis is known to require the secreted signaling ligand Wnt8. Wnt8 signaling promotes ventral fates and antagonizes the expansion of the dorsal domain known as the organizer. Maintenance of the organizer is critical for proper development as this tissue is known to produce inhibitors of Wnt and BMP (Bone Morphogenetic Protein) family ligands; BMPs are also known to play a major role in promoting ventral fates. In order to understand how Wnt8 antagonizes the organizer, we analyzed the epistatic relationship between Wnt8 and the transcriptional repressors Vent and Vox using zebrafish as a model organism. We found that Wnt8/β-catenin signaling directly regulates the transcriptional levels of vent and vox so that they can repress the transcription of dorsal genes on the ventral side of the embryo. To understand the contribution of Wnt8 towards ventral fate specification, we carefully analyzed its relationship with BMP signaling during gastrula stages. We found that bmp expression in the mesoderm is under the control of Wnt8 at mid-gastrulation and that regulation of bmp explains many of the ventral defects observed in wnt8 mutants. Antagonism of the expression of organizer-derived BMP inhibitors by Wnt8 also indirectly allows timely BMP signaling. Analysis of wnt8; bmp double mutants revealed an early unsuspected function of BMP in the antagonism of the organizer. Further, we uncovered a mechanism through which regulation of vent, vox and a related-gene ved expression by both Wnt8 and BMP antagonizes dorsal/axial mesoderm identity to preserve the integrity of ventral/non-axial tissues. In summary, we have revealed some of the mechanisms of Wnt8 function in D/V mesoderm patterning: it restricts the organizer domain by regulating vent and vox, it allows BMP induced differentiation through its inhibition of BMP antagonists derived from the organizer and it co-regulates vent, vox, and ved with BMP signaling to allow maintenance of the non-axial domain.