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FEEDING HUNGRY PLANTS: THE SECRETED PURPLE ACID PHOSPHATASE ISOZYMES AtPAP12 AND AtPAP26 PLAY A PIVOTAL ROLE IN EXTRACELLULAR PHOSPHATE SCAVENGING IN ARABIDOPSIS THALIANAROBINSON, Whitney Drummond 28 August 2012 (has links)
Orthophosphate (Pi) is a limiting macronutrient in most soils and is essential for plant metabolism. Massive amounts of Pi-fertilizers are applied to agricultural fields to compensate for this limitation. However, Pi-fertilizers are made from non-renewable rock Pi-sources and their application is environmentally destructive. Plants have evolved numerous ways to survive in Pi-deficient (-Pi) soils, including the upregulation and secretion of acid phosphatases (APases). APases catalyze the hydrolysis of phosphate (Pi) from Pi-esters in an acidic environment. The major group of plant secreted APases, purple acid phosphatases (PAPs), have been hypothesized to scavenge Pi from organic-Pi (Po) sources that can compose up to 80% of the total P-content of some soils. Previous biochemical and proteomic studies indicate that AtPAP26 and AtPAP12 are the predominant secretory PAP isozymes upregulated by –Pi Arabidopsis thaliana cell cultures and seedlings. This thesis examines the influence of different Po supplements on the growth, Pi content, secretory APase activity, and secreted AtPAP12 and AtPAP26 polypeptides of wildtype (Col-0) Arabidopsis seedlings. Additionally, this thesis assesses the potential role that AtPAP12 and AtPAP26 play in scavenging Pi from extracellular Po sources by utilizing a homozygous atpap12/atpap26 double knockout mutant. Loss of AtPAP26 and AtPAP12 expression resulted in a 64% decrease in root secreted APase activity of –Pi seedlings. These results corroborate previous findings implying that: (i) Arabidopsis are able to grow on a variety of extracellular Po sources as their sole source of P-nutrition, and (ii) AtPAP12 and AtPAP26 are the principal contributors to secreted APase activity of –Pi Arabidopsis. Total shoot Pi levels, and growth of atpap12/atpap26 Arabidopsis seedlings cultivated in -Pi/+Po media were significantly lower relative to Col-0 controls, but unaffected under Pi sufficient conditions. The atpap12/atpap26 seedlings were unable to grow in a –Pi/+Po soil, whereas the Col-0 seedlings were able to develop. Additionally, both PAPs were strongly upregulated on root surfaces and in shoot cell wall extracts of –Pi seedlings. Taken together, these results strongly suggest that AtPAP12 and AtPAP26 play an important role in the hydrolysis of Pi from extracellular Po and make a large contribution to Pi-recycling and scavenging in –Pi Arabidopsis. / Thesis (Master, Biology) -- Queen's University, 2012-08-23 11:36:45.722
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Porting AUTOSAR to a high performance embedded systemZhang, Shuzhou January 2013 (has links)
Automotive embedded systems are going through a major change, both in terms of how they are used and in terms of software and hardware architecture. Much more powerful and rapidly evolvable hardware is expected, paralleled by an accelerating development rate of the control software. To meet these challenges, a software standard, AUTOSAR, is gaining ground in the automotive field. In this work, experiences from porting AUTOSAR to a high performance embedded system, Raspberry Pi, are collected. The goal is both to present experience on the process of AUTOSAR porting and to create an AUTOSAR implementation on a cheap and widely accessible hardware platform, making AUTOSAR available for researchers and students.
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Point spread function engineering in fluorescence spectroscopySchönle, Andreas. January 1900 (has links) (PDF)
Heidelberg, Univ., Diss., 2003. / Computerdatei im Fernzugriff.
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A study of substituent effects on the rates, regiospecificity and stereospecificity in the di-pi-methane rearrangementKlun, Robert Thomas. January 1977 (has links)
Thesis--Wisconsin. / Vita. Includes bibliographical references.
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4Pi-konfokale Fluoreszenzmikroskopie mit 1-Photonen-AnregungBewersdorf, Jörg. Unknown Date (has links) (PDF)
Universiẗat, Diss., 2002--Heidelberg.
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The sociolinguistic correlates of dialect contact and koineisation in Medini Arabic : lenition and resyllabificationHussain, Abeer January 2017 (has links)
This is a sociolinguistic investigation that focuses on variation and change in Medini Arabic (Saudi Arabia). Data in the form of sociolinguistic interviews were collected from 58 speakers, and analysed quantitatively within the framework of the quantitative variationist paradigm using Rbrul. The study investigates the correlation between two linguistic variables and the social variables of age, gender and community (urban and Bedouin). The dialects under investigation originate from two different norms: ‘Bedouin’, in this study a sub-type of Najdi; and ‘Sedentary’, the traditional dialect of Medina (viz. Medini). The Bedouin group share the same origin and culture whilst the urban group come from different ethnic and cultural backgrounds. The first linguistic variable is (ʤ), which has two realisations in both communities: a traditional affricate [ʤ] and an innovative fricative [ʒ]. The second linguistic variable is resyllabification, which is precipitated by syncope or epenthesis. The innovative variant for the urban group is syncope whereas for the Bedouin group it is epenthesis. Overall, the results indicate that both dialects are undergoing levelling of marked linguistic features and change in progress towards the adoption of koineised or supra-local forms. In the case of (ʤ), the change towards the innovative form is led by the younger women in both communities. With respect to the resyllabification variable, the age group of adult (30-44) urban and Bedouin men take the lead in syncope and epenthesis, respectively. The interpretation of the results is twofold: (i) linguistic, where the results are interpreted within the principles of Optimality Theory and Moraic Theory; (ii) sociolinguistic, where the focus is on social structure, socio-political and socioeconomic change in the locality.
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A study of the differential cross-section and analyzing powers of the pp-->[pi]+d reaction at intermediate energiesGiles, Gordon Lewis January 1985 (has links)
The polarized and unpolarized differential cross-sections and the analyzing power angular distributions of the pp→π⁺ d reaction have been measured to a statistical precision of better than one percent over several incident proton beam energies between 350 and 500 MeV for center-of-mass angles from 20° to 150°. The unpolarized differential cross-sections were measured at 350, 375, 425, and 475 MeV with unpolarized incident beams. The polarized differential cross-sections and analyzing powers were measured at 375, 450, and 498 MeV using polarized incident beams. Angular distributions of the unpolarized and polarized differential cross-sections are expanded into Legendre and Associated Legendre polynomial series respectively, and the ai°° and biⁿ° expansion coefficients fit to the respective measurements. The resulting coefficients are compared with existing data and recent theoretical predictions.
The observation of significant non-zero a₆°° coefficent is interpreted as indication of a significant contribution from the ¹G₄ N-N partial wave channel at energies as low as 498 MeV. / Science, Faculty of / Physics and Astronomy, Department of / Graduate
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Software development of Biosignal Pi : An affordable open source platform for monitoring ECG and respiration / Utveckling av mjukvara till Biosignal Pi : En open-source plattform för övervakning av EKG och andningSnäll, Jonatan January 2014 (has links)
In order to handle the increasing costs of healthcare more of the care and monitoring will take place in the patient’s home. It is therefore desirable to develop smaller and portable systems that can record important biosignals such as the electrical activity of the heart in the form of an ECG. This project is a continuation on a previous project that developed a shield that can be connected to the GPIO pins of a Raspberry Pi, a credit-card sized computer. The shield contains an ADAS1000, a low power and compact device that can record the electrical activity of the heart along with respiration. The aim of this project was to develop an application that can run on the Raspberry Pi in order to display the captured data from the shield on a screen along with storing the data for further processing. The project was successful in the way that the requirements for the software have been fulfilled. / För att hantera den ökande kostnaden för hälso- och sjukvård kommer en större del av övervakning samt vård att ske i patientens hem. Det kommer därför att vara önskvärt att utveckla mindre system som är lättare att hantera än de större traditionella apparaterna för att samla in vanliga biosignaler som exempelvis ett EKG. Detta projekt är en fortsättning på ett tidigare projekt vars syfte var att framställa en ”sköld” som kan kopplas ihop med en Raspberry Pi via dess GPIO pinnar. Det föregående projektet var lyckat och en sköld innehållande en ADAS1000 som kan samla in bl.a. ett EKG samt andningen framställdes. Syftet med detta projekt var att utveckla en applikation som kan köras på en Raspberry Pi och på så sätt visa den data som samlas in från skölden på en skärm. Det skulle även vara möjligt att spara insamlad data för senare användning. Projektet resulterade i en applikation som uppfyllde dessa krav.
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Drug-Associated Changes in Amino Acid Residues in Gag p2, p7<sup>NC</sup>, and p6<sup>Gag</sup>/p6<sup>Pol</sup> in Human Immunodeficiency Virus Type 1 (HIV-1) Display a Dominant Effect on Replicative Fitness and Drug ResponseHo, Sarah, Coman, Roxana M., Bunger, Joshua C., Rose, Stephanie L., O'Brien, Patricia, Munoz, Isabel, Dunn, Ben M., Sleasman, John W., Goodenow, Maureen M. 01 September 2008 (has links)
Regions of HIV-1 gag between p2 and p6Gag/p6Pol, in addition to protease (PR), develop genetic diversity in HIV-1 infected individuals who fail to suppress virus replication by combination protease inhibitor (PI) therapy. To elucidate functional consequences for viral replication and PI susceptibility by changes in Gag that evolve in vivo during PI therapy, a panel of recombinant viruses was constructed. Residues in Gag p2/p7NC cleavage site and p7NC, combined with residues in the flap of PR, defined novel fitness determinants that restored replicative capacity to the posttherapy virus. Multiple determinants in Gag have a dominant effect on PR phenotype and increase susceptibility to inhibitors of drug-resistant or drug-sensitive PR genes. Gag determinants of drug sensitivity and replication alter the fitness landscape of the virus, and viral replicative capacity can be independent of drug sensitivity. The functional linkage between Gag and PR provides targets for novel therapeutics to inhibit drug-resistant viruses.
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Matériaux moléculaires électro-stimulables et assemblages organisés reposant sur des briques élémentaires de type pi-dimères / Electron-responsive molecular materials and organized assemblies based on Pi-radicals as building blocks.Abdul-Hassan, Wathiq Sattar 14 February 2018 (has links)
Le but de cette proposition est d'explorer un nouveau concept de matériaux moléculaires sensibles à l'oxydoréduction. Les architectures commutables électron-sensibles ont longtemps été reconnues comme le choix le plus simple et le plus viable pour produire des dispositifs pratiques, mais la conception efficace de tels systèmes à l'échelle moléculaire reste un défi. L'approche développée dans ce projet repose sur la production électrochimiquement déclenchée de radicaux pi à partir de dérivés de viologène, l'objectif étant d'induire la formation d'une liaison non-covalente et réversible entre ces radicaux pi pour contrôler la conformation des échafaudages supramoléculaires. Les nanomatériaux comprendront des fils moléculaires provenant de polymères de coordination et des fils moléculaires produits par des interactions π le long de l'axe du fil, mis en œuvre par des interactions faibles périphériques telles que l'agrégation des chaînes latérales lipophiles ou la liaison H. Les efforts initiaux se concentreront sur l'optimisation de la formation de π-dimères et de pimer, avec ou sans assistance d'interactions secondaires. Après avoir déterminé les paramètres qui produisent l'auto-assemblage dirigé π le plus efficace, des motifs basés sur les viologènes appropriés seront introduits dans des blocs de construction plus sophistiqués. Tout au long de la synthèse des assemblages, la π-dimérisation utilisée comme force motrice principale pour l'auto-assemblage des nanomatériaux peut être consolidée par un blocage covalent des structures. En fin de compte, l'électrostimulation des systèmes π fournira des assemblages moléculaires dynamiques dans lesquels la morphologie sera sensible aux stimuli redox. / The aim of this proposal is to explore a new concept of redox-responsive molecular materials. Electron-responsive switchable architectures have long been recognized as the most straightforward and viable choice to produce practical devices but efficiently designing such systems on the molecular scale still remains a challenge. The approach developed in this project relies on the electrochemically triggered production of pi-radicals from viologen derivatives, the objective being to induce the formation of non-covalent and reversible binding between these pi-radicals to control the conformation of supramolecular scaffolds. The nanomaterials will comprise molecular wires arising from coordination polymers and molecular wires produced by π-interactions along the wire's axis implemented by peripheral weak interactions such as lipophilic side chain aggregation or H-bonding. The initial efforts will focus on the optimization of π-dimer and pimer formation, with or without assistance of secondary interactions. After determining the parameters that yield the most efficient π directed self-assembly, suitable viologen based motifs will be introduced in more sophisticated building blocks. Throughout the synthesis of the assemblies, π-dimerization that is used as the primary driving force for the self-assembly of nanomaterials may be consolidated by covalent locking of the structures. In the end, the electro-stimulation of π systems will provide dynamic molecular assemblies in which the morphology will be responsive to redox stimuli.
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