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Showing 11 to 20 of 20 (0.035 seconds)Spelling suggestions: "subject:"pfp"" "subject:"ffp""
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Increasing the Quantum Yield of Red Fluorescent Proteins Using Rational DesignPandelieva, Antonia January 2016 (has links)
Monomeric red fluorescent proteins (RFPs) are used extensively for applications in molecular biology research, and are especially suited for whole body imaging applications due to their longer excitation and emission wavelengths, which are less damaging and penetrate deeper into animal tissue. However, these proteins suffer from reduced brightness compared to other fluorescent proteins, and require further engineering, which is often achieved through random methods, incurring large time and resource costs. Here we propose a rational design approach to improve the quantum yield of RFPs by reducing conformational variability of the chromophore. We engineered mRojoA, a mutant containing a π-stack involving Tyr197 and the chromophore phenolate, to include the P63F/H/Y mutations on its other side, by simultaneously mutating neighbouring positions 16, 143, and 163. The brightest mutants that we found in each library, mRojo-VYGV, mRojo-VFAV, and mRojo-VHSV, exhibited 1.8- to 2.4-fold increases in brightness, and quantum yield increases of up to 2.1-fold. In all three mutants, the increases in brightness were predominantly due to improvements in the quantum yield and not the extinction coefficient. Solving the crystal structures of two of these mutants along with a dim variant allowed us to strongly infer a link between rigidity of the chromophore and increased quantum yield. In addition, back-mutating position 63 in the highest quantum yield mutant, mRojo-VYGV, reversed the improvement in quantum yield, indicating that Y63 was the primary residue responsible for the improved brightness of the protein. Unfortunately, the mCherry-VYGV mutant did not achieve a similar increase in quantum yield or brightness. This is likely due to the lack of a second bulky aromatic residue at position 197, which is present in mRojoA. Nevertheless, this rational approach could be applied to some other RFPs whose chromophores exhibit increased conformational variability in order to further improve their brightness.
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Resistive Wall Mode Stability and Control in the Reversed Field PinchYadikin, Dmitriy January 2006 (has links)
Control of MHD instabilities using a conducting wall together with external magnetic fields is an important route to improved performance and reliability in fusion devices. Active control of MHD modes is of interest for both the Advanced Tokamak and the Reversed Field Pinch (RFP) configurations. A wide range of unstable, current driven MHD modes is present in the RFP. An ideally conducting wall facing the plasma can in principle provide stabilization to these modes. However, a real, resistive wall characterized by a wall field diffusion time, cannot stabilize the ideal MHD modes unless they rotate with Alfvénic velocity, which is usually not the case. With a resistive wall, the ideal modes are converted into resistive wall modes (RWM) with growth rates comparable to the inverse wall time. Resistive wall modes have been studied in the EXTRAP T2R thin shell RFP device. Growth rates have been measured and found in agreement with linear MHD stability calculations. An advanced system for active control has been developed and installed on the EXTRAP T2R device. The system includes an array of 128 active saddle coils, fully covering the torus surface. Experiments on EXTRAP T2R have for the first time demonstrated simultaneous active suppression of multiple independent RWMs. In experiments with a partial array, coupling of different modes due to the limited number of feedback coils has been observed, in agreement with theory. Different feedback strategies, such as the intelligent shell, the rotating shell, and mode control have been studied. Further, feedback operation with different types of magnetic field sensors, measuring either the radial or the toroidal field components have been compared / QC 20100929
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Green and red fluorescent protein tagging of endogenous proteins in glioblastoma using the CRISPR (clustered regularly interspaced short palindromic repeats)-Cas9 systemLindvall, Jenny January 2016 (has links)
Glioblastoma multiforme is the most malignant primary brain tumor that affects adults, recognized by the World Health Organization as an aggressive grade IV astrocytoma. Patients diagnosed with this type of tumor are left with a poor prognosis even with the most advanced treatment available. The cancer is quite heterogeneous and is typically categorized into four different subtypes depending on genetic aberrations and patient characteristics. Furthermore, researchers have discovered a subpopulation of glioblastoma cells, known as cancer stem cells, which are thought to be resistant to current therapies and responsible for tumor reoccurrence and relapse. Previous studies, in addition to this one, have found that the differentiation of glioblastoma cells downregulate nestin protein expression, the selected stem cell marker, and upregulate glial fibrillary acid protein expression, the selected differentiation marker, using immunofluorescence. Thus, one alternative treatment option is to understand the mechanism underlying the differentiation of cancer stem cells. Four cell cultures representative of each glioblastoma subtype will be endogenously tagged using the genome editing system, Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR/Cas9). The representative stem cell marker, nestin, will be tagged with a green fluorescent protein, while the chosen differentiation marker, glial fibrillary acid protein, will be tagged with a red fluorescent protein. Several drugs were screened to analyze whether the drugs had a differentiation effect on the glioblastoma cells. As a result, strong evidence indicated that bone morphogenetic protein four upregulated glial fibrillary acid protein expression levels to the same extent as the differentiation control media using 5% fetal bovine serum. The goal of this study is to establish a method to directly monitor the differentiation process of glioblastoma cells as a novel molecular screening method. In this case, all glioblastoma cells, even the ones resistant to treatment, can be eliminated through an initial “pre-treatment” by forcing differentiation of cancer stem cells, making the cells more susceptible to the chemotherapy drugs. In the long run, glioblastoma patients would have a chance at a more positive prognosis; a longer life that is free of glioblastoma. / Master Thesis in Applied Biotechnology
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Resonant magnetic perturbation effect on the tearing mode dynamics : Novel measurements and modeling of magnetic fluctuation induced momentum transport in the reversed-field pinchFridström, Richard January 2017 (has links)
The tearing mode (TM) is a resistive instability that can arise in magnetically confined plasmas. The TM can be driven unstable by the gradient of the plasma current. When the mode grows it destroys the magnetic field symmetry and reconnects the magnetic field in the form of a so-called magnetic island. The TMs are inherent to a type of device called the reversed-field pinch (RFP), which is a device for toroidal magnetic confinement of fusion plasmas. In the RFP, TMs arise at several resonant surfaces, i.e. where the field lines and the perturbation have the same pitch angle. These surfaces are closely spaced in the RFP and the neighboring TM islands can overlap. Due to the island overlap, the magnetic field lines become tangled resulting in a stochastic magnetic field, i.e. the field lines fill a volume instead of lying on toroidal surfaces. Consequently, a stochastic field results in an anomalously fast transport in the radial direction. Stochastic fields can also arise in other plasmas, for example, the tokamak edge when a resonant magnetic perturbation (RMP) is applied by external coils. This stochastization is intentional to mitigate the edge-localized modes. The RMPs are also used for control of other instabilities. Due to the finite number of RMP coils, however, the RMP fields can contain sidebands that decelerate and lock the TMs via electromagnetic torques. The locking causes an increased plasma-wall interaction. And in the tokamak, the TM locking can cause a plasma disruption which is disastrous for future high-energy devices like the ITER. In this thesis, the TM locking was studied in two RFPs (EXTRAP T2R and Madison Symmetric Torus) by applying RMPs. The experiments were compared with modern mode-locking theory. To determine the viscosity in different magnetic configurations where the field is stochastic, we perturbed the momentum via an RMP and an insertable biased electrode. In the TM locking experiments, we found qualitative agreement with the mode-locking theory. In the model, the kinematic viscosity was chosen to match the experimental locking instant. The model then predicts the braking curve, the short timescale dynamics, and the mode unlocking. To unlock a mode, the RMP amplitude had to decrease by a factor ten from the locking amplitude. These results show that mode-locking theory, including the relevant electromagnetic torques and the viscous plasma response, can explain the experimental features. The model required viscosity agreed with another independent estimation of the viscosity. This showed that the RMP technique can be utilized for estimations of the viscosity. In the momentum perturbation experiments, it was found that the viscosity increased 100-fold when the magnetic fluctuation amplitude increased 10-fold. Thus, the experimental viscosity exhibits the same scaling as predicted by transport in a stochastic magnetic field. The magnitude of the viscosity agreed with a model that assumes that transport occurs at the sound speed -- the first detailed test of this model. The result can, for example, lead to a clearer comparison between experiment and visco-resistive magnetohydrodynamics (MHD) modeling of plasmas with a stochastic magnetic field. These comparisons had been complicated due to the large uncertainty in the experimental viscosity. Now, the viscosity can be better constrained, improving the predictive capability of fusion science. / <p>QC 20171122</p>
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Tearing mode dynamics in the presence of resonant magnetic perturbationsFridström, Richard January 2016 (has links)
Magnetically confined fusion (MCF) plasmas are typically subject to several unstable modes. The growth of one mode can limit the plasma energy confinement and might cause a termination of the plasma. Externally applied resonant magnetic perturbations (RMPs) are used to control and to mitigate some of the unstable modes. Examples are, mitigation of edge localized modes and steering of neoclassical tearing mode position for stabilization by electron cyclotron current drive. Consequently, use of RMPs are considered necessary in planned future fusion machines. There are however negative consequences, the RMP interaction with a tearing mode (TM) of the same resonance can cause deceleration of the TM and possibly wall-locking. If a TM is non-rotating relative the machine-wall, it can grow and degrade fusion plasma performance and lead to a plasma disruption. Thus, all fusion confinement machines want to avoid wall-locked modes. Resonant magnetic fields can also be present in the form of machine-error-fields, which can produce the same effects. Clearly, it is of importance to understand the TM-RMP interaction. Typically, the modes with long wavelength are described by magnetohydrodynamic (MHD) theory. Considering the finite plasma resistivity, MHD predicts a mode that tears and reconnects magnetic field lines, called a tearing mode (TM). TMs occur at surfaces where the magnetic field lines close on themselves after a number of (m) toroidal and (n)poloidal turns. These surfaces are resonant in the sense that magnetic field and helical current perturbation has the same helicity, which minimize stabilizing effect of magnetic field line bending. In this thesis, the mechanisms of TM locking and unlocking due to external resonant magnetic perturbations (RMPs) are experimentally studied. The studies are conducted in two MCF machines of the type reversed-field pinch (RFP): EXTRAP T2R and Madison Symmetric Torus (MST). The studied machines exhibit multiple rotating TMs under normal operation. In EXTRAP T2R TM locking and unlocking are studied by application of a single harmonic RMP. Observations show that after the TM is locked, RMP amplitude has to be reduced significantly in order to unlock the TM. In similar studies in MST unlocking is not observed at all after turn-off of the RMP. Hence, in both machines, there is hysteresis in the locking and subsequent unlocking of a tearing mode. Results show qualitative agreement with a theoretical model of the TM evolution when subjected to an RMP. It is shown that the RMP cause a reduction of TM and plasma rotation at the resonant surface. The velocity reduction is opposed by a viscous torque from surrounding plasma. After TM locking, relaxation of the whole plasma rotation is observed, due to the transfer of velocity reduction via viscosity. This results in a reduced viscous resorting torque, which explains the observed hysteresis. The hysteresis is further deepened by the increase in amplitude of a locked mode. / <p>QC 20160111</p>
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Fatores críticos sobre manifestações de interesse em Parcerias Público-Privadas e as propriedades da visão do produto / Critical success factors of unsolicited proposal in Public-Private Partnerships and product vision propertiesCaproni, Tiago Vieira 08 March 2018 (has links)
Os Procedimentos de Manifestação de Interesse (PMI) e Propostas Não Solicitadas (PNS) são mecanismos para a viabilização de projetos de Parcerias Público-Privadas (PPP/PFIs). Contudo, a ausência de critérios claros para avaliação e priorização de parceiros, de forma transparente e técnica, leva à seleção adversa de propostas, contribuindo para o insucesso dos projetos. O principal instrumento utilizado na avaliação PPP/PFIs é uma análise quantitativa baseada no Value For Money (VfM). O propósito deste trabalho foi investigar os problemas relacionados com os processos de avaliação das propostas dos PMI submetidas aos órgãos demandantes dos serviços. Iniciou-se com a análise do Fatores Críticos para o Sucesso (FCSs) das PPP/PFIs, dos PMI e PNS, identificadas na literatura. Os Fatores Críticos foram apresentados a um conjunto de 78 especialistas que responderam também sobre a processo de análise das propostas. No questionário os autores foram confrontados também com as propriedades da visão. O resultado indica que a análise com o VfM seria incompleta e insuficiente para capturar a complexidade do escopo destes projetos. A pesquisa possibilitou ainda organizar os fatores críticos em 7 dimensões a serem consideradas na avaliação destes projetos. Essas dimensões podem ser utilizadas para a criação de instrumentos de avaliação e um exemplo foi proposto, um indicador nomeado de índice \"T\", avaliado por um grupo de 12 especialistas em projetos de PPP/PFIs. A pesquisa contribui, portanto, para apoiar a criação de instrumentos de avaliação de PPP/PFIs que considerem uma análise mais ampla, considerando aspectos qualitativos e quantitativos. / Unsolicited Proposals (UNPs) are one of the main mechanisms for verifying the feasibility of Public-Private Partnerships (PPP/PFIs/PFIs) projects. However, the lack of clear criteria to evaluate and to prioritize the partner, in a transparent and technical way, has led to adverse selection of proposals increasing the level of failure of these projects. The main instrument used in the PPP/PFIs evaluation is a quantitative analysis based on Value for Money. The purpose of this research was to investigate the problems related with the processes of evaluation of the Unsolicited Proposals (UNPs) that are submitted to the respective government offices. The study compiles the analysis of Critical Success Factors (CSFs) for Public-Private Partnerships (PPP/PFI) and the Unsolicited Proposals (UNPs), identified in the literature, and synthetized by the evaluation of a group of 78 specialists, resulting in the organization of 7 (seven) dimensions to be considered in the evaluation of these projects. This study also demonstrated that, according to these experts, the analysis with VfM would be incomplete and insufficient to capture the complexity of the scope of these projects. As an alternative a set of 7 (seven) indicators where created related to each dimension and a general index that synthetize the performance in the dimensions, considering qualitative and quantitative aspects. The index was labeled as \"T\" index and evaluated by a group of 12 (twelve) experts on PPP/PFI projects. The results from the analyses indicate that the index allows a linear comparative analysis between the proposals received by the public entity requesting the Public- Private Partnership (PPP/PFI) services. The model of indicators decreases the subjectivity of the choices made by public managers, resulting in greater transparency for the process of proposal qualification and security to the market.
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Fatores críticos sobre manifestações de interesse em Parcerias Público-Privadas e as propriedades da visão do produto / Critical success factors of unsolicited proposal in Public-Private Partnerships and product vision propertiesTiago Vieira Caproni 08 March 2018 (has links)
Os Procedimentos de Manifestação de Interesse (PMI) e Propostas Não Solicitadas (PNS) são mecanismos para a viabilização de projetos de Parcerias Público-Privadas (PPP/PFIs). Contudo, a ausência de critérios claros para avaliação e priorização de parceiros, de forma transparente e técnica, leva à seleção adversa de propostas, contribuindo para o insucesso dos projetos. O principal instrumento utilizado na avaliação PPP/PFIs é uma análise quantitativa baseada no Value For Money (VfM). O propósito deste trabalho foi investigar os problemas relacionados com os processos de avaliação das propostas dos PMI submetidas aos órgãos demandantes dos serviços. Iniciou-se com a análise do Fatores Críticos para o Sucesso (FCSs) das PPP/PFIs, dos PMI e PNS, identificadas na literatura. Os Fatores Críticos foram apresentados a um conjunto de 78 especialistas que responderam também sobre a processo de análise das propostas. No questionário os autores foram confrontados também com as propriedades da visão. O resultado indica que a análise com o VfM seria incompleta e insuficiente para capturar a complexidade do escopo destes projetos. A pesquisa possibilitou ainda organizar os fatores críticos em 7 dimensões a serem consideradas na avaliação destes projetos. Essas dimensões podem ser utilizadas para a criação de instrumentos de avaliação e um exemplo foi proposto, um indicador nomeado de índice \"T\", avaliado por um grupo de 12 especialistas em projetos de PPP/PFIs. A pesquisa contribui, portanto, para apoiar a criação de instrumentos de avaliação de PPP/PFIs que considerem uma análise mais ampla, considerando aspectos qualitativos e quantitativos. / Unsolicited Proposals (UNPs) are one of the main mechanisms for verifying the feasibility of Public-Private Partnerships (PPP/PFIs/PFIs) projects. However, the lack of clear criteria to evaluate and to prioritize the partner, in a transparent and technical way, has led to adverse selection of proposals increasing the level of failure of these projects. The main instrument used in the PPP/PFIs evaluation is a quantitative analysis based on Value for Money. The purpose of this research was to investigate the problems related with the processes of evaluation of the Unsolicited Proposals (UNPs) that are submitted to the respective government offices. The study compiles the analysis of Critical Success Factors (CSFs) for Public-Private Partnerships (PPP/PFI) and the Unsolicited Proposals (UNPs), identified in the literature, and synthetized by the evaluation of a group of 78 specialists, resulting in the organization of 7 (seven) dimensions to be considered in the evaluation of these projects. This study also demonstrated that, according to these experts, the analysis with VfM would be incomplete and insufficient to capture the complexity of the scope of these projects. As an alternative a set of 7 (seven) indicators where created related to each dimension and a general index that synthetize the performance in the dimensions, considering qualitative and quantitative aspects. The index was labeled as \"T\" index and evaluated by a group of 12 (twelve) experts on PPP/PFI projects. The results from the analyses indicate that the index allows a linear comparative analysis between the proposals received by the public entity requesting the Public- Private Partnership (PPP/PFI) services. The model of indicators decreases the subjectivity of the choices made by public managers, resulting in greater transparency for the process of proposal qualification and security to the market.
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Podnikatelský záměr rozvoje společnosti / Entrepreneurial Project of Business DevelopmentHavlů, Monika January 2012 (has links)
The present dissertation is the design of a company's business plan, with a view to the new monitoring system, with all the important factors such as economic and technical factors, and legislative changes in the branch are taken into consideration. Furthermore there is the view to the economic standing of the company is also evalua-ted. The business plan is simultaneously considered from a general view of potential implementation of the proposed solution.
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The Characterisation of Putative Nuclear Pore-Anchoring Proteins in Arabidopsis thalianaCollins, Patrick January 2013 (has links)
The nuclear pore complex (NPC) is perhaps the largest protein complex in the eukaryotic cell, and controls the movement of molecules across the nuclear envelope. The NPC is composed of up to 30 proteins termed nucleoporins (Nups), each grouped in different sub-complexes. The transmembrane ring sub-complex is composed of Nups responsible for anchoring the NPC to the nuclear envelope. Bioinformatic analysis has traced all major sub-complexes of the NPC back to the last eukaryotic common ancestor, meaning that the nuclear pore structure and function is conserved amongst all eukaryotes. In this study Arabidopsis T-DNA knockout lines for these genes were investigated to characterise gene function. Differences in plant growth and development were observed for the ndc1 knockout line compared to wild-type but gp210 plants showed no phenotypic differences. The double knockout line gp210 ndc1 was generated through crosses to observe plant response to the knockout of two anchoring-Nup genes. No synergistic affect from this double knockout was observed, suggesting that more, as yet unidentified Nups function the transmembrane ring in plants. The sensitivity to nuclear export inhibitor leptomycin B (LMB) was tested also for knockout lines, although growth sensitivity to the drug was not observed. Nucleocytoplasmic transport of knockout lines was measured in cells transformed by particle bombardment. To express fluorescent protein constructs actively transported through the NPC, localisation of protein determined the nucleocytoplasmic transport of the cell. The ndc1single knockout and the double knockout gp210 ndc1 exhibited decreased nuclear export. Further experiments in determining NDC1 localisation and identification of other Nups in the transmembrane ring sub-complex would bring a more comprehensive understanding to the plant NPC.
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A plm implementation for aerospace systems engineering-conceptual rotorcraft designHart, Peter Bartholomew 08 April 2009 (has links)
The thesis will discuss the Systems Engineering phase of an original Conceptual Design Engineering Methodology for Aerospace Engineering-Vehicle Synthesis. This iterative phase is shown to benefit from digitization of Integrated Product&Process Design (IPPD) activities, through the application of Product Lifecycle Management (PLM) technologies. Requirements analysis through the use of Quality Function Deployment (QFD) and 7 MaP tools is explored as an illustration. A "Requirements Data Manager" (RDM) is used to show the ability to reduce the time and cost to design for both new and legacy/derivative designs. Here the COTS tool Teamcenter Systems Engineering (TCSE) is used as the RDM. The utility of the new methodology is explored through consideration of a legacy RFP based vehicle design proposal and associated aerospace engineering. The 2001 American Helicopter Society (AHS) 18th Student Design Competition RFP is considered as a starting point for the Systems Engineering phase. A Conceptual Design Engineering activity was conducted in 2000/2001 by Graduate students (including the author) in Rotorcraft Engineering at the Daniel Guggenheim School of Aerospace Engineering at the Georgia Institute of Technology, Atlanta GA. This resulted in the "Kingfisher" vehicle design, an advanced search and rescue rotorcraft capable of performing the "Perfect Storm" mission, from the movie of the same name. The associated requirements, architectures, and work breakdown structure data sets for the Kingfisher are used to relate the capabilities of the proposed Integrated Digital Environment (IDE). The IDE is discussed as a repository for legacy knowledge capture, management, and design template creation. A primary thesis theme is to promote the automation of the up-front conceptual definition of complex systems, specifically aerospace vehicles, while anticipating downstream preliminary and full spectrum lifecycle design activities. The thesis forms a basis for additional discussions of PLM tool integration across the engineering, manufacturing, MRO and EOL lifecycle phases to support business management processes.
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