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Functional and Topological Analysis of Acyl-CoA:Diacylglycerol Acyltransferase 2 From Saccharomyces cerevisiaeLiu, Qin Unknown Date
No description available.
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Functional and Topological Analysis of Acyl-CoA:Diacylglycerol Acyltransferase 2 From Saccharomyces cerevisiaeLiu, Qin 06 1900 (has links)
Acyl-CoA:diacylglycerol acyltransferase (EC 2.3.1.20, DGAT or DAGAT) is a membrane protein found mainly in the endoplasmic reticulum (ER). It catalyzes the final step in the biosynthesis of triacylglyerol (TAG or TG), which is the principal repository of fatty acids for energy utilization and membrane formation. Several lines of evidence have indicated that DGAT has a substantial effect on carbon flux into TAG. DGAT has at least two discrete family members (DGAT1 and DGAT2) with different physiological roles. High-resolution structures of both DGATs, however, are absent due to difficulties in purification. In order to gain insight into structural and functional relationships of DGATs, a functional DGAT2 protein from the yeast Saccharomyces cerevisiae (ScDGAT2, also known as Dgalp) was selected. The structural and functional role of cysteine residues in ScDGAT2 was studied using site-directed mutagenesis (SDM) in combination with chemical modification. Although ScDGAT2 is susceptible to thiol-modifying reagents, none of the cysteines are essential for the catalytic activity or involved in structure support though disulfide linkages. Inhibition of DGAT activity by thiol-specific modification was localized to cysteine314, which is in the proximity of a highly conserved motif in DGAT2s. Thus, cysteine314 may reside in a crucial position near a possible active site or related to proper protein folding. The functional importance and topological orientation of signature motifs in ScDGAT2 were also studied using the same methods. Both the N- and C-termini of ScDGAT2 are oriented toward the cytosol. A highly conserved motif, 129YFP131, and a hydrophilic segment exclusive to ScDGAT2, reside in the ER and play essential roles in enzyme catalysis. In addition, the strongly conserved H195, which may be part of the active site of DGAT2, is likely embedded in the membrane. Although ScDGAT2 has a topology similar to that of murine DGAT2, there are striking differences which suggest that the topological organization of DGAT2 is not ubiquitously conserved. / Plant Science
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The Wave Structure Function And Temporal Frequency Spread In Weak To Strong Optical TurbulenceMasino, Aaron J. 01 January 2004 (has links)
This paper presents analytic expressions for the wave structure function, frequency spread of the temporal frequency spectrum, and the temporal frequency spectrum of optical signals propagating through a random medium, specifically the Earth’s atmosphere. The results are believed to be valid for all optical turbulence conditions. These expressions are developed using the Rytov approximation method. Generally, the validity of statistical quantities obtained via this method is restricted to conditions of weak optical turbulence. However, in this work, by using a modification of the effective atmospheric spectral model presented by Andrews et al. for scintillation index, wave structure function expressions have been derived that are valid in all turbulence conditions as evidenced by comparison to experimental data. Analytic wave structure function results are developed for plane, spherical, and Gaussian-beam waves for one-way propagation. For the special case of a spherical wave, comparisons are made with experimental data. The double pass case is also considered. Analytic expressions for the wave structure function are given that incorporate reflection from a smooth target for an incident spherical wave. Additionally, analytic expressions for the frequency spread of the temporal frequency spectrum and the temporal frequency spectrum itself, after one-way propagation for horizontal and slant paths, are derived for plane and spherical waves. These results are also based on the Rytov perturbation method . Expressions that are believed to be valid in all turbulence conditions are also developed by use of the effective atmospheric spectral model used in the wave structure function development. Finally, double pass frequency spread expressions are also presented. As in the case of the wave structure function, reflection from a smooth target with an incident spherical wave is considered.
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Enhanced structure-function relationship in glaucoma with an anatomically and geometrically accurate neuroretinal rim measurementDanthurebandara, V.M., Sharpe, G.P., Hutchison, D.M., Denniss, Jonathan, Nicolela, M.T., McKendrick, A.M., Turpin, A., Chauhan, B.C. January 2015 (has links)
Yes / Purpose: To evaluate the structure–function relationship between disc margin–based rim area (DM-RA) obtained with confocal scanning laser tomography (CSLT), Bruch's membrane opening–based horizontal rim width (BMO-HRW), minimum rim width (BMO-MRW), peripapillary retinal nerve fiber layer thickness (RNFLT) obtained with spectral-domain optical coherence tomography (SD-OCT), and visual field sensitivity.
Methods: We examined 151 glaucoma patients with CSLT, SD-OCT, and standard automated perimetry on the same day. Optic nerve head (ONH) and RNFL with SD-OCT were acquired relative to a fixed coordinate system (acquired image frame [AIF]) and to the eye-specific fovea-BMO center (FoBMO) axis. Visual field locations were mapped to ONH and RNFL sectors with fixed Garway-Heath (VFGH) and patient-specific (VFPS) maps customized for various biometric parameters.
Results: Globally and sectorally, the structure–function relationships between DM-RA and VFGH, BMO-HRWAIF and VFGH, and BMO-HRWFoBMO and VFPS were equally weak. The R2 for the relationship between DM-RA and VFGH ranged from 0.1% (inferonasal) to 11% (superotemporal) whereas that between BMO-HRWAIF and VFGH ranged from 0.1% (nasal) to 10% (superotemporal). Relatively stronger global and sectoral structure–function relationships with BMO-MRWAIF and with BMO-MRWFoBMO were obtained. The R2 between BMO-MRWAIF and VFGH ranged from 5% (nasal) to 30% (superotemporal), whereas that between BMO-MRWFoBMO and VFPS ranged from 5% (nasal) to 25% (inferotemporal). The structure–function relationship with RNFLT was not significantly different from that with BMO-MRW, regardless of image acquisition method.
Conclusions: The structure–function relationship was enhanced with BMO-MRW compared with the other neuroretinal rim measurements, due mainly to its geometrically accurate properties.
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Structure-function relationships in wax producing enzymesKawelke, Steffen Justus 03 December 2014 (has links)
No description available.
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LSST primary/tertiary monolithic mirrorSebag, J., Gressler, W., Liang, M., Neill, D., Araujo-Hauck, C., Andrew, J., Angeli, G., Cho, M., Claver, C., Daruich, F., Gessner, C., Hileman, E., Krabbendam, V., Muller, G., Poczulp, G., Repp, R., Wiecha, O., Xin, B., Kenagy, K., Martin, H. M., Tuell, M. T., West, S. C. 08 August 2016 (has links)
At the core of the Large Synoptic Survey Telescope (LSST) three-mirror optical design is the primary/tertiary (M1M3) mirror that combines these two large mirrors onto one monolithic substrate. The M1M3 mirror was spin cast and polished at the Steward Observatory Mirror Lab at The University of Arizona (formerly SOML, now the Richard F. Caris Mirror Lab at the University of Arizona (RFCML)). Final acceptance of the mirror occurred during the year 2015 and the mirror is now in storage while the mirror cell assembly is being fabricated. The M1M3 mirror will be tested at RFCML after integration with its mirror cell before being shipped to Chile.
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Determining the effect of structure and function on 3D bioprinted hydrogel scaffolds for applications in tissue engineeringGodau, Brent 30 August 2019 (has links)
The field of tissue engineering has grown immensely since its inception in the late 1980s. However, currently commercialized tissue engineered products are simple in structure. This is due to a pre-clinical bottleneck in which complex tissues are unable to be fabricated. 3D bioprinting has become a versatile tool in engineering complex tissues and offers a solution to this bottleneck. Characterizing the mechanical properties of engineered tissue constructs provides powerful insight into the viability of engineered tissues for their desired application. Current methods of mechanical characterization of soft hydrogel materials used in tissue engineering destroy the sample and ignore the effect of 3D bioprinting on the overall mechanical properties of a construct. Herein, this work reports on the novel use of a non-destructive method of viscoelastic analysis to demonstrate the influence of 3D bioprinting strategy on mechanical properties of hydrogel tissue scaffolds. 3D bioprinting is demonstrated as a versatile tool with the ability to control mechanical and physical properties. Structure-function relationships are developed for common 3D bioprinting parameters such as printed fiber size, printed scaffold pattern, and bioink formulation. Further studies include effective real-time monitoring of crosslinking, and mechanical characterization of multi-material scaffolds. We envision this method of characterization opening a new wave of understanding and strategy in tissue engineering. / Graduate
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Study on the Structure and Function of Suppressor of K+ Transport Growth Defect (SKD1) Protein from Mesembryanthemum crystallinum using BioinformaticsKuo, Yu-Mei 23 July 2004 (has links)
SKD1 (suppressor of potassium transport growth defect) belongs to the AAA-ATPase family and is one of the class E VPS (vacuolar protein sorting) proteins. The ATPase activity-deficient form of SKD1 leads the perturbation of mechanism transport through endosomes and lysosomes, however, the molecular mechanism behind the action of SKD1 is poorly understood. In this study, it is identified that VPS4_YEAST (Saccharomyces cerevisiae) is the homology protein of mcSKD1 (Mesembryanthemum crystallinum SKD1) employing sequence profile analysis. The full-length mcSKD1 protein possesses MIT, AAA-ATPase, and NACHT domains of VPS4_YEAST. It is investigated that VPS4_YEAST (NACHT domain) interacts to BRO1_YEAST (HEAT repeat), BRO1_YEAST (HEAT repeat) to AIP1_YEAST (WD40 repeat), AIP1_YEAST (WD40 repeat) to ABP1_YEAST (ADF domain), ABP1_YEAST (ADF domain) to ARP2_YEAST (ACTIN domain), respectively, from yeast two-hybrid system via protein-protein interaction. These proteins employ the function of cytoskeleton structural proteins in cells. Hence, mcSKD1 protein may involve the mechanisms of potassium ion uptake and salt tolerance via the function of cytoskeleton structural proteins.
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A Qcd Analysis Of High Energy Neutrino-nucleon InteractionsGamsizkan, Halil 01 January 2003 (has links) (PDF)
In this thesis, a leading-order QCD analysis of structure functions in neutrinonucleon
interactions is performed. From the CCFR nucleon structure function
data, the QCD parameter Lambda has been extracted. This measurement also
corresponds to a measurement of the strong coupling constant. Two fits to the
data have been performed, the nonsinglet-only fit and the singlet-nonsinglet
combined fit. The result for Lambda was found to be 289 +62
¡ / 59 § / 76 MeV, where
the errors are statistical and systematical, respectively. This result is compared
to the world-wide measurements of this quantity. In order to verify the agreement,
also the logarithmic slopes of the QCD model and the structure function
data are calculated and compared.
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Studium receptorů pro opioidy / Study of opioid receptorsCechová, Kristína January 2016 (has links)
1 ABSTRACT In this Thesis, we studied properties of μ-, δ-, and κ-opioid receptors in lymphocytes isolated from rat spleen. This splenocytes were exposed to mitogen concanavalin A or opiate morphine and cultivated for 48 hours. Under physiological conditions, level of opioid receptors in immune cells is very low. Due to various factors such as presence of opioids, mitogens, long-term exposition to stress, expression of these receptors can be amplified. In this study we demonstrated, that concanavalin A causes up-regulation of μ-, δ- and κ-opioid receptors in lymphocytes isolated from rat spleen. In control cells no significant signal of μ- or δ-receptors was observed. In contrast, κ-opioid receptors were detected already in control cells. Concanavalin A stimulation caused a 2.4 - fold increase of these receptors. In lymphocytes treated with morphine only μ-opioid receptors were up-regulated, whereas in control cells, there was no signal for these receptor type. δ-opioid receptors were not detected in control or morphine treated cells. κ-opioid receptors were determined in control and also in morphine affected lymphocytes but the amount of these receptors wasn't changed by morphine. Detection of μ-, δ- and κ-opioid receptors using Western blot technique in lymphocytes isolated from rat spleen, that were...
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