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THE DESIGN AND DEVELOPMENT OF THE PROTOTYPE ENHANCED FLIGHT TERMINATION SYSTEMVetter, Jeff S., Cribbet, Travis 10 1900 (has links)
International Telemetering Conference Proceedings / October 20-23, 2003 / Riviera Hotel and Convention Center, Las Vegas, Nevada / Range Safety Systems are used for destruction of a vehicle should a malfunction cause the vehicle to
veer off course. All vehicles launched into space require implementation of a Range Safety System.
For years the IRIG receivers have been used with relatively good success. Unfortunately, the IRIG
receivers do not provide a high level of security. High alphabet receivers were later developed for
use on the big launchers (Atlas, Delta, Titan, etc) and the manned missions (Shuttle) to provide
added security. With the IRIG based system, several problems have occurred resulting in the loss
millions of dollars worth of equipment. Due to the problems that have occurred it has become
apparent that there is a need for a more secure, low cost, type of range safety receiver.
This paper describes the design and development of the prototype EFTS system. Mission critical
parameters are discussed including selection of the encryption and forward error correction
algorithms. Actual measured performance including message error rate characteristic is presented.
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A Security Constrained AC Economic Dispatch Framework for Allocation of Balanced and Unbalanced Financial Transmission RightsRajan, Balaji 31 March 2005 (has links)
In a deregulated power market financial transmission rights (FTR) serve as a mechanism for protecting market participants from price variation resulting from network congestion. Possession of FTRs allows participants to recover congestion related losses resulting from unequal locational marginal prices that arise from out of merit dispatch. There exists different strategies for allocating FTR which are in use in the deregulated market. Designing a comprehensive framework for market specific FTR allocation that includes factors like unbalanced FTR, FTR for losses and AC-OPF is currently a major research issue in the deregulated power industry.
This thesis develops a method for allocation of financial transmission rights that maximizes revenue while satisfying the system security constraints of alternating current (AC) networks and the revenue adequacy constraint of the financial market. Both the maximization of the FTR revenue and maintaining the constraints are accomplished through solving a modified version of the optimal power flow program. The methodology developed here considers allocation of both balanced and unbalanced point to point FTR obligations.
The design of the framework is centered around three main scenarios that arise in the allocation of FTR. In the first scenario the total FTR bid quantity is much less than the total generation quantity available in the network. To maximize revenue the ISO will allocate the entire quantity and needs to only determine the loss quantity associated with the FTR quantity.
In the second scenario the total FTR bid quantity is much greater than the total generation quantity available in the network. The ISO is required to determine the maximum allocatable FTR bid per bus in the network for the given generation limit in the network. A novel adaptation of the OPF program that maximizes the total FTR quantity allocated is run in this case to determine the maximum allocatable bid quantities. The third scenario is when the total FTR bid quantity is less than the total generation quantity available in the network but when the losses stipulated by the FTR quantity are added to the bid quantity the total generation capacity is exceeded. Here the novel adaptation of the OPF program is run to determine the maximum allocatable FTR bid quantity per bus (ceiling values). The original FTR bid quantities are then allocated upto the ceiling values determined.
When multiple FTR bids are offered on a point-to-point node pair, allocation of FTRs among the bidders for that node pair is done through an auction process. Various auction strategies such as first price uniform, discriminatory auction, and second price uniform auction are considered. The performance of the FTR allocation process is evaluated for the above auction strategies through sample IEEE networks with 9 and 32 buses, available in the MATPOWER software.
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Caractérisation biochimique et fonctionnelle d’une nouvelle thiorédoxine plastidiale (TRX z) chez Arabidopsis Thaliana / Biochemical and functional characterisation of a new plastidial thioredoxin (TRX z) in Arabidopsis ThalianaBohrer, Anne-Sophie 20 December 2012 (has links)
Un des principaux acteurs impliqués dans la régulation du statut redox intracellulaire, permettant aux plantes de s’adapter aux contraintes environnementales, est une famille multigénique de petites (12-14 kDa) oxydoréductases ubiquistes appelées thiorédoxines (TRX). Le génome d’Arabidopsis code une vingtaine de TRX canoniques dont neuf sont plastidiales (TRX f, m, x et y). Très étudiées dans notre laboratoire par des approches biochimiques, les TRX de types f et m apparaissent réguler majoritairement l’activité d’enzymes impliquées dans le métabolisme primaire tandis que les types x et y servir principalement de substrats réducteurs d’enzymes antioxydantes. Plus récemment, une dixième TRX, proposée plastidiale et nommée TRX z, a été identifiée. Au cours de ma thèse, j’ai caractérisé cette nouvelle TRX chloroplastique montrant des propriétés physico-chimiques inhabituelles, la rendant unique. En effet, la TRX z semble interagir, via des interactions électrostatiques, avec des protéines pour former des complexes de masses moléculaires élevées, potentiellement liés aux acides nucléiques. De plus, la TRX z, dont l’expression est induite à la lumière, principalement dans les tissus photosynthétiques, est la première TRX chloroplastique qui n’est pas réduite par le système FTR à la lumière mais qui peut être réduite par les autres TRX plastidiales, suggérant une interconnexion entre ces différentes TRX. D’autre part, une recherche exhaustive de cibles de la TRX z, par deux approches spécifiques et complémentaires (protéomique et double hybride), ont révélé 90 cibles putatives de la TRX z. La plupart de ces cibles, jamais identifiées comme cibles des TRX, sont impliquées dans la réponse de défense des plantes mise en place lors de stress biotiques. Ces résultats suggèrent que la TRX z pourrait être un élément clé dans la mise en place de ces réponses. L’analyse fonctionnelle préliminaire de la TRX z au cours de la réponse immune innée conforte cette hypothèse. L’ensemble de ces résultats indique que la TRX z pourrait jouer le rôle d’une protéine senseur de l’état d’oxydoréduction de la cellule. / One of the main actors involved in regulation of the cellular redox state, which allow plant adaptation to stress environmental conditions, is a multigenic family of small (12-14 kDa) ubiquitous oxidoreductases named thioredoxins (TRX). Arabidopsis encodes around twenty canonical TRX, including nine plastidial isoforms (TRX f, m, x and y). Extensively studied in our laboratory by biochemical approaches, TRX f and m was found to mainly redox regulate the activity of enzymes involved in the primary metabolism whereas TRX x and y serve as reducing substrates for antioxidant enzymes. More recently, a tenth TRX, predicted plastidial and named TRX z, was identified. During my PhD, I have characterized this new plastidial TRX showing unusual physicochemical properties, making it unique. Indeed, TRX z seems to interact, via electrostatic bonds, with proteins to form high molecular weight complexes, potentially linked to nucleic acids. Moreover, TRX z, which is expressed in green tissues in the light, is the first plastidial TRX which is not reduced by the FTR system but which can be reduced by other plastidial TRX, suggesting an interconnection between these TRX. Furthermore, a large scale inventory of TRX z targets, by two specific and complementary approaches (proteomic and yeast two hybrid), revealed 90 putative TRX z targets. Most of these, which have never been identified as TRX targets before, are implicated in plant defense response to biotic stresses. These results suggest that TRX z might be a key player in these responses. Preliminary functional analysis of TRX z during immune innate response reinforces this hypothesis. Altogether, these results indicate that TRX z appears as an important sensor of the redox status of the cell.
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Characterization of the ferredoxin/thioredoxin system and its targets in Physcomitrella patens / Caractérisation de mutants du système ferrédoxine-thiorédoxine chez Physcomitrella patensGütle, Desirée 29 March 2017 (has links)
La régulation redox est un mécanisme ancien présent chez les organismes biologiques et impliquée dans diverses voies métaboliques. En particulier chez les organismes photosynthétiques elle est responsable des mécanismes d‘adaptation rapide dans un environnement constamment modifié. Dans les chloroplastes le système ferrédoxine/thiorédoxine est la cascade redox principale qui relie l‘activité de plusieurs enzymes plastidiales à la source lumineuse. Le rôle central dans ce système est joué par la ferrédoxine-thiorédoxine réductase (FTR), une protéine hétérodimérique qui récupère des électrons à partir de la ferrédoxine photoréduite et les transfère pour réduire des thiorédoxines plastidiales. Ces protéines peuvent alors réduire des enzymes cibles, requérant l‘accessibilité de paires de cystéines dans un disulfure dont la réduction résulte en une activation/ inactivation de la cible. Jusqu‘à présent des plantes viables n‘ont pu être obtenues en l‘absence de ce système de régulation. Dans cette thèse des secteurs du système redox ont été explorés chez la plante modèle Physcomitrella patens (une mousse). Par manipulation de gènes l‘influence de l‘enzyme FTR sur la croissance et le développement de la plante a été analysée suivant différents paramètres. De manière à impacter la fonction de la réductase des changements nucléotidiques simples ont été introduits au niveau des codons programmant les cystéines catalytiques et dans un deuxième temps le gène complet a été supprimé. De façon inattendue nous n‘avons observé aucun effet significatif sur la viabilité et le développement des plantes mutantes. De plus, nous avons détecté dans P. patens des thiorédoxines additionnelles absentes chez les plantes à graine qui sont fonctionnelles vis à vis des enzymes cibles mais non-réduites par la FTR. Ceci rend possible un scénario de compensation chez les mutants via un système de réduction FTR-indépendant qui reste à caractériser. Deux des cibles photorégulées, la fructose-1,6-bisphosphatase (FBPase) et la sédoheptulose-1,7-bisphosphatase (SBPase), fonctionnent dans la phase de régénération du cycle de Calvin-Benson cycle et elles possèdent plusieurs caractéristiques de catalyse et de régulation similaires. En combinant des approches biochimiques et structurales, une comparaison fonctionnelle et structurale des deux phosphatases de P. patens a été conduite. De plus l‘analyse phylogénétique a révélé une origine procaryotique indépendante des deux séquences en dépit de leurs similitudes structurales et catalytiques. De plus trois articles de revue résument la plasticité et la représentativité du modèle P. patens pour la recherche forestière, les principes généraux de la régulation redox relativement aux aspects évolutifs et fonctionnels chez les plantes ainsi que l‘ état de l‘art de la régulation redox chez les espèces ligneuses en utilisant principalement le peuplier comme modèle / Redox regulation is an ancient mechanism present in biological organisms and is involved in diverse cellular pathways. In particular in photosynthetic organisms it is responsible for fast adaption mechanisms to a constantly changing environment. In chloroplasts the ferredoxin/thioredoxin system represents the main redox regulatory cascade which links the activity of several plastid enzymes to the energy source, light. A central role in this system is played by the heterodimeric ferredoxin-thioredoxin reductase (FTR), which gains electrons from the photo-reduced ferredoxin and transfers those further on via reduction to plastidal thioredoxins. Those proteins in turn reduce their target enzymes and require therefore the availability of redox sensitive cysteine pairs whose reduction results in an inactivation/activation switch of the targets. So far no viable plants could be obtained in complete absence of this redox regulation system. In this thesis single sections of the system were explored in the model plant Physcomitrella patens. Through gene manipulation the influence of the FTR enzyme on plant growth and development was analysed. In order to impact on the function of the reductase, firstly single nucleotide exchange of the catalytic cysteines was performed and later on the gene was completely deleted. Surprisingly, no significant effect could be observed on the viability and development of mutant lines compared to WT plants. Furthermore we found that P. patens possesses in contrast to seed plants additional thioredoxins which are functional for reduction of FTR target enzymes but are most likely not supplied with electrons by this reductase. Thus a possible rescue scenario independent of FTR could be assumed for P. patens and also by other redox regulation systems present in chloroplasts. Two of the FTR target enzymes, fructose-1,6-bisphosphatase and sedoheptulose-1,7-bisphosphatase, are functional in the regeneration phase of the Calvin-Benson cycle and share similar characteristics in regulation and catalysis. By combining biochemical and structural approaches, a functional comparison of both phosphatases was conducted using cDNAs from P. patens. A stricter TRX-dependent regulation and catalytic cleavage ability for both substrates, FBP and SBP, could be observed for PpSBPase, whereas PpFBPase is only capable of cleaving FBP. By obtaining the oxidized X-ray structure of both enzymes these observations can be associated with the distinct positions of regulatory sites and the various sizes of the substrate binding pocket. In addition, the phylogenetic analysis revealed an independent prokaryotic origin for both phosphatases. Furthermore we summarized in three review articles the amenability of P. patens as model plant for forest research, the general principles of redox regulation in respect of evolution and functional mechanisms in plants, and the current state of the art in forest redox regulation using poplar as exemplary model
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A Model for Strategic Bidding in Combined Transmission and Wholesale Energy MarketsGupte, Sanket 01 July 2004 (has links)
Motivated by deregulation in major service sectors like airlines, banking and telecommunication, the electric industry is undergoing a major transformation. However due to design inefficiencies, restructuring of the power sector, so far, has not been a major success. A lack of comprehensive quantitative models has resulted in the inability of the market designers to evaluate market performance and develop successful market designs. A comprehensive model should include market features like two-settlement system, transmission congestion, financial transmission rights (FTRs), demand elasticity, demand-side bidding and other market rules.
The contribution of this thesis includes development of an exhaustive modeling framework that includes the above mentioned market features and also development of a computationally effective solution methodology. The market designers would use this methodology in the development of alternative conceptual market design frameworks, and also for assessing the impact of various market rules on market performance.
The noncooperative bidding behavior of the generators in both FTR and energy markets are modeled as nonzero-sum stochastic games. Since the bidding strategies in the FTR and energy games are dependent on each other and jointly impact the market performance, a two-tier learning approach is developed. Players (e.g. generators) first bid in the FTR market. FTR bids are then taken into account in the process of selecting bids in the energy market. The FTR bids and the energy bids together decide the market equilibrium and the resulting performance. This performance measure is then used to evaluate success of FTR bidding strategy. Several example power networks are studied to expose the modeling and learning based solution approach.
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Untersuchungen zur Kurzzeit-Regulation und Adaptation von Photosynthese und Elektronenverteilung in Chloroplasten und transgenen KartoffelpflanzenHoltgrefe, Simone 10 June 2003 (has links)
Die in dieser Arbeit durchgeführten Untersuchungen dienten zur Identifizierung von Faktoren, die das Zusammenspiel zwischen dem photosynthetischen Elektronentransport und den Reaktionen im Stroma koordinieren. Hierzu erfolgten Manipulationen von Elektronen- und/oder Metabolitverfügbarkeit im Chloroplasten. Als Untersuchungsmaterial dienten zunächst isolierte Spinat-Chloroplasten unter sättigendem CO2 und Pi. Durch die Herstellung transgener Kartoffelpflanzen, welche die zentralen Elektronenverteiler Fd I und FTR über- bzw. unterexprimieren, wurde die Elektronenverfügbarkeit im Chloroplasten dann dauerhaft verändert.
Auswirkungen von zusätzlichen Elektronenakzeptoren auf den Chloroplastenmetabolismus
Die Zugabe von verschieden „starken“ Elektronenakzeptoren zu Chloroplasten während der „steady state“-Photosynthese bei ausreichendem Lichtangebot hatte zwei Effekte zur Folge. Ein moderater Elektronenentzug (0,2 und 2 mM OAA, 0,2 mM Nitrit) beeinträchtigte ausschließlich den Aktivierungszustand der NADP-MDH, während die Aktivierungszustände von NAD(P)-GAPDH, FBPase und PRK nahezu unverändert waren. Auch qN, der stromale Metabolitgehalt und die [14CO2]-Fixierung waren nur geringfügig beeinflußt. qP hingegen war stark erhöht. Im Gegensatz dazu inhibierten Nitrit bzw. Methylviologen in höheren Konzentrationen die [14CO2]-Fixierung. Das ATP/ADP-Verhältnis stieg an und das NADPH/NADP-Verhältnis war nahezu unverändert. Eine extreme Erhöhung war im DHAP/PGA-Verhältnis und der stromalen FBP-Menge meßbar. Die Aktivierungszustände von FBPase und NADP-MDH nahmen nach Zugabe stark ab, während die Aktivierungszustände von NAD(P)-GAPDH und PRK unbeeinflußt blieben.
Zusammenspiel von Elektronenangebot und Effektoren auf die Redoxmodulation von Chloroplastenenzymen
Eine Veränderung im Elektronenangebot durch variierende Lichtintensitäten verdeutlichte, daß bei höheren Lichtintensitäten ein Großteil der Elektronen nicht für die CO2-Fixierung genutzt werden kann. Parallel zur Sättigung der CO2-Fixierung stiegen FBPase- und NADP-MDH-Aktivierungszustände an, während PRK und NAD(P)-GAPDH schon bei Intensitäten von 50 µE den maximalen Aktivierungszustand erreichten. Die Zugabe von Intermediaten, die positiv bzw. negativ auf den Aktivierungszustand der einzelnen Enzyme wirken, hatten wieder bei NADP-MDH und FBPase die deutlichsten Auswirkungen. Sowohl NAD(P)-GAPDH- als auch PRK-Aktivierungszustände waren nur unter Bedingungen erniedrigt, unter denen der Elektronenfluß stark herabgesetzt ist und im Stroma wenig ATP, Triosephosphate und 3PGA vorhanden sind. Demgegenüber reagiert NADP-MDH sehr sensitiv auf Umlenkung oder Erhöhung des Elektronenflusses. Im Fall der FBPase bestehen lineare Zusammenhänge zwischen FBP-Gehalt oder aktuellem Elektronendruck und dem Aktivierungszustand des Enzyms.
Die an Chloroplasten erhaltenen Ergebnisse zeigen:
Die Redoxmodulation im Licht spielt weder bei PRK noch bei NAD(P)-GAPDH eine herausragende Rolle. Die Bedeutung dieses grundlegenden Regulationsmechanismus liegt für beide Enzyme im Licht/Dunkel- und Dunkel/Licht-Übergang. Durch die „feed back“-Regulation der NADP-MDH durch NADP erfolgt bei diesem Enzym immer eine direkte Rückkopplung auf die Elektronenverfügbarkeit im Stroma. Aufgrund der sensitiven Reaktion auf Änderungen im NADPH/NADP-Verhältnis stellt das Enzym einen sehr guten Marker für den im Stroma vorherrschenden Elektrondruck dar. Die sensitiven Schritte im Calvin-Zyklus stellen die FBPase und die sehr ähnlich regulierte SBPase dar. Der aktivierende Effekt von FBP auf die FBPase wird durch den Elektronendruck in der Weise beeinflußt, daß eine Erhöhung der Lichtintensität in höheren Enzymaktivitäten unter vergleichbaren FBP-Konzentrationen resultieren. Bei einer Limitierung im Elektronenangebot scheint die Aktivierung dann unabhängig vom FBP-Gehalt zu sein. Restriktionen im Calvin-Zyklus, die zu einer verminderten FBP-Bereitstellung bei hohem Elektronenangebot führen, reichen für eine Aktivierung ebenfalls nicht aus. Somit stellt der aktuelle Aktivierungszustand des Enzyms einen kombinierten Effekt aus Elektronenverfügbarkeit und FBP-Gehalt dar.
Manipulation der Elektronenflüsse in vivo durch Veränderugen im Fd-Gehalt
Die Transformation von Kartoffelpflanzen mit dem homologen fed 1-cDNA-Klon (diese Arbeit) in „antisense“-Orientierung bewirkte eine maximal 50%ige Reduktion im Fd I-Proteingehalt. Eine weitere Reduktion im Fd I-Gehalt scheint für die Pflanze letal zu sein. Sowohl moderat supprimierte (80-100% des Wildtyp-Gehaltes) als auch stärker supprimierte Linien (50-80%) wiesen verstärkten zyklischen Elektronentransport und eine verringerte CO2-Assimilationsrate auf, zeigten aber kein Anzeichen von O2-Reduktion. Als Schutz gegen oxidativen Stress war in den „antisense“-Linien ein verminderter Elektronenfluß nachweisbar, indem die Effizienz der Lichtnutzung von PSI und PSII vermindert war. Dabei wurden zwei Strategien deutlich, die aber beide zu weniger funktionellem PS II und verringerten Quantenausbeuten führten: In den moderaten Linien war ein extremer DpH für diesen Effekt verantwortlich, während die stärker supprimierten Linien Photoinhibition zeigten. Weiterhin trat in den „antisense“-Linien eine bis zu 25%ige Reduktion im Chlorophyllgehalt bei erhöhten Chlorophyll a/b-Verhältnissen auf. Eine solche Akklimatisierung tritt bei Pflanzen auf, die an schwache Lichtintensitäten adaptiert sind und Starklicht ausgesetzt werden. Eine Überexpression des heterologen fed 1-cDNA-Klon aus Spinat in Kartoffelpflanzen hatte gegenteilige Effekte zur Folge. Die Elektronentransportketten zwischen den Photosystemen waren weniger reduziert, die Transformanten wiesen in Kurzzeitversuchen eine bis zu 10% höhere CO2-Assimilation auf und auch die Effizienz der Lichtnutzung war erhöht. Die im Vergleich zu Wildtyp-Pflanzen stark erhöhten Chlorophyllfluoreszenz-Endsignale deuten darauf hin, daß ein größerer Anteil stromaler Akzeptoren reduziert vorliegt. Gleichzeitig war das Chlorophyll a/b-Verhältnis erniedrigt. In Abhängigkeit von der Fd I-Menge, und im Endeffekt vermutlich durch die im Stroma verfügbare Akzeptor-Menge bedingt, erfolgt eine Erhöhung bzw. Erniedrigung von qP. Der permanent erhöhte Redoxstatus zwischen den Photosystemen scheint in den Fd I-Transformanten eine Adaptation des Chlorophyll a/b-Verhältnisses in die Richtung zu bewirken, daß im Fall der Unterexprimierer eine Anpassung in Richtung Starklicht erfolgt, während die Überexprimierer eine Schwachlichtanpassung zeigen. Ein Hinweis in diese Richtung ist die gute Korrelation zwischen qP und dem Chlorophyll a/b-Verhältnis.
Isolierung von ftr a- und ftr b-cDNA-Klonen aus Kartoffel und Herstellung transgener Kartoffelpflanzen
Für eine Manipulation der Elektronenflüsse in Richtung Td erfolgte eine „antisense“-Transformation mit dem ftr b-cDNA-Klon aus Kartoffelblatt (diese Arbeit). Die primären Transformanten wiesen keinen Phänotyp auf. Eine Transformation im heterologen System mit dem „antisense“-ftr b-cDNA-Klon aus Spinat erwies sich als ineffektiv. Eine Überexpression des ftr b-cDNA-Klons aus Spinat in Kartoffel war erfolgreich; Pflanzen mit Cosuppression wurden nicht gefunden. Auch erfolgte in diesen Pflanzen keine Coregulation in der Expression der FTR A-Untereineinheit. Für eine Überexpression von funktioneller FTR könnte der ftr a-cDNA-Klon aus Kartoffelblatt (diese Arbeit) zusammen mit dem ftr b-cDNA-Klon transformiert werden.
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An Evidence-Based Educational Intervention to Improve Nursing Staff's Critical Thinking and Decision-Making SkillsBarron-Kagan, Rene Norene 01 January 2016 (has links)
An Evidence-Based Educational Intervention to Improve Nursing Staff's Critical Thinking and Decision-Making Skills
by
Rene N. Kagan
MSN, University of New Mexico, 2009
BS, University of Phoenix, 2000
Project Submitted in Partial Fulfillment
of the Requirements for the Degree of
Doctor of Nursing Practice
Walden University
September 2016
Hospitalized patients in acute care settings are at a high risk of developing health complications that can eventually lead to failure to rescue (FTR) situations. The aim of this project was to deliver a structured comprehensive medical-surgical competency plan for acute care nurses to detect deterioration in a patient's condition through the triad of assessment model to promote clinical reasoning among acute care nurses. Data were collected using pretest surveys, a demographic sheet, and an evaluation survey. A convenient sample of between 22 and 29 nursing staff was recruited from three medical-surgical inpatient units at a VA Hospital. The pretest survey, administered simultaneously with the educational modules, assessed participants' baseline knowledge on components of the triad of assessment model and the processes involved in the prevention of FTR. The pretest scores for modules 1 to 6 were 2, 3, 3, 3, 2, and 3 respectively. The posttests scores for modules 1 to 6 were 4, 5, 5, 5, 4, and 5 respectively. The nurse's aides also recorded posttest scores of 4.6 for both Pulse Oximetry and orthostatic hypotension modules. The t-test (p<0.00) showed a significant difference between the pre and posttests scores, thus, indicating an improvement in nursing staff's knowledge regarding the triad of assessment model. Thus, it is important to adopt a comprehensive medical-surgical plan for acute care nurses institutional-wide. This project contributes to social change through identification of a medical-surgical intervention that improves nurses' critical thinking skills, thereby promoting patient satisfaction and safety. Because nurses play a significant role at the bedside, improved critical thinking skills will facilitate a significant reduction in FTR rates, heighten patient satisfaction, and enhance the nurse-patient relationship.
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Equilibrium Bidding in Joint Transmission and Energy MarketsBabayigit, Cihan 08 November 2007 (has links)
Participants in deregulated electric power markets compete for financial transmission rights (FTRs) to hedge against losses due to transmission congestion by submitting bids to the independent system operator (ISO). The ISO obtains an FTR allocation, that maximizes sales revenue while satisfying simultaneous feasibility. This FTR allocation remains in place for a length of time during which the participants compete in the energy market to maximize their total payoff from both FTR and energy markets. Energy markets (bi-lateral, day ahead, real time) continue until the the end of the current FTR period, at which time the participants can choose to modify their FTR holdings for the next FTR period. As in any noncooperative game, finding Nash equilibrium bidding strategies is of critical importance to the participants in both FTR and energy markets. In this research, a two-tier matrix game theoretic modeling approach is developed that can be used to obtain equilibrium bidding behavior of the participants in both FTR and energy markets considering the total payoff from FTR and energy. The matrix game model presents a significant deviation from the bilevel optimization approach commonly used to model FTR and energy allocation problems. A reinforcement learning (RL) algorithm is also developed which uses a simulation model and a value maximization approach to obtain the equilibrium bidding strategies in each market. The model and the RL based solution approach allow consideration of multi-dimensional bids (for both FTR and energy markets), network contingencies, varying demands, and many participants.
The value iteration based RL algorithm obtains pure strategy Nash equilibrium for FTR and energy allocation. A sample network with three buses and four participants is considered for demonstrating the viability of the game theoretic model for FTR market. A PJM network example with five buses, five generators and three loads is also considered to analyze equilibrium bidding behavior in joint FTR and energy markets. Several numerical experiments on the sample networks are conducted using the approach of statistical design of experiments (DOE) to assess impacts of variations of bid and network parameters on the market outcomes like participant payoffs and equilibrium strategies.
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FLEXIBLE NETWORK TRANSCEIVER NEXT GENERATION TELEMETRY NETWORKINGBrown, K. D., Klimek, John 10 1900 (has links)
ITC/USA 2005 Conference Proceedings / The Forty-First Annual International Telemetering Conference and Technical Exhibition / October 24-27, 2005 / Riviera Hotel & Convention Center, Las Vegas, Nevada / This paper describes the Flexible Telemetry Transceiver (FNT)-a modular, scalable,
standards-based, software configurable, microwave wireless telemetry network
transceiver. The FNT enables flexible, high-rate, long-range, duplex, network services
across multipoint to multipoint wireless channel.
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Characterization of the thioredoxin system in Methanosarcina mazeiLoganathan, Usha R. 18 December 2014 (has links)
Thioredoxin (Trx) and thioredoxin reductase (TrxR) along with an electron donor form a thioredoxin system. Such systems are widely distributed among the organisms belonging to the three domains of life. It is one of the major disulfide reducing systems, which provides electrons to several enzymes, such as ribonucleotide reductase, methionine sulfoxide reductase and glutathione peroxidase to name a few. It also plays an important role in combating oxidative stress and redox regulation of metabolism. Trx is a small redox protein, about 12 kDa in size, with an active site motif of Cys-X-X-Cys. The reduction of the disulfide in Trx is catalyzed by TrxR. Two types of thioredoxin reductases are known, namely NADPH thioredoxin reductase (NTR) with NADPH as the electron donor and ferredoxin thioredxoin reductase (FTR) which depends on reduced ferredoxin as electron donor. Although NTR is widely distributed in the three domains of life, it is absent in some archaea, whereas FTRs are mostly found in plants, photosynthetic eukaryotes, cyanobacteria, and some archaea.
The thioredoxin system has been well studied in plants, mammals, and a few bacteria, but not much is known about the archaeal thioredoxin system. Our laboratory has been studying the thioredoxin systems of methanogenic archaea, and a major focus has been on Methanocaldococcus jannaschii, a deeply rooted archaeon that has two Trxs and one TrxR. My thesis research concerns the thioredoxin system of the late evolving members of the group which are exposed to oxygen more frequently than the deeply rooted members of the group, and have several Trxs and TrxRs. Methanosarcina mazei is one such organism, whose thioredoxin system is composed of one NTR, two FTRs, and five Trx homologs.
Characterization of the components of a thioredoxin system sets the basis to further explore its function. I have expressed in Escherichia coli and purified the five Trxs and three TrxRs of M. mazei. I have shown the disulfide reductase activities in MM_Trx1 and MM_Trx5 by their ability to reduce insulin with DTT as the electron donor, and that in MM_Trx3 through the reduction of DTNB by this protein with NADPH as the electron donor, and in the presence of NTR as the enzyme. MM_Trx3 was found to be the only M. mazei thioredoxin to accept electrons through the NTR, and to form a complete Trx - NTR system. The Trx - FTR systems are well studied in plants, and such a system is yet to be defined in archaea. I have proposed a mechanism of action for one of the FTRs. FTR2 harbors a rubredoxin domain, and this unit is the only rubredoxin in this organism. Superoxide reductase, an enzyme that reduces superoxide radical to hydrogen peroxide without forming oxygen, utilizes rubredoxin as the direct electron source and this enzyme is found in certain anaerobes, including Methanosarcina species. Thus, it is possible that FTR2 provides electrons via a Trx to the superoxide reductase of M. mazei. This activity will define FTR2 as a tool in combating oxidative stress in M. mazei.
In my thesis research I have laid a foundation to understand a complex thioredoxin system of M. mazei, to find the role of each Trx and TrxR, and to explore their involvement in oxidative stress and redox regulation. / Master of Science
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