To see the other types of publications on this topic, follow the link: Differential modulator.
Dissertations / Theses on the topic 'Differential modulator'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Differential modulator.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Nathany, Sumit Kumar. "Design of a 14-bit fully differential discrete time delta-sigma modulator /." Online version of the thesis, 2006. https://ritdml.rit.edu/dspace/handle/1850/2799.
Full text
2
Schick, Christoph. "Design and vectorial fourport characterisation of differential 40Gbit/s modulator drivers in Si-SiGe HBT technology." Düsseldorf VDI-Verl, 2008. http://d-nb.info/988190877/04.
Full text
3
Pereira, Nuno Ruben Ferreira. "Implementation of a sigma delta modulator for a class D audio power amplifier." Master's thesis, Faculdade de Ciências e Tecnologia, 2013. http://hdl.handle.net/10362/10046.
Full text
4
Bilbao, Héctor Uhalte. "DAB Transmission System Simulation." Thesis, Linköping University, Department of Electrical Engineering, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-2595.
Full textAbstract:
DAB (Digital Audio Broadcasting) is the radio digital system developed as an european standard by the ETSI, EN 300 400, based on the Eureka-147 group works, to improve the performance of the analogue radio systems (AM and FM). The system is based on the OFDM technology which allows DAB to exploit the spectrum frequencies in a better way with a higher quality of sound for mobile receivers specially. The main part of the OFDM system is based on the FFT algorithms to spread the data flow over different orthogonal carriers. The simulation has been developed in SimulinkTMand MatlabTMand the layout designed follows faithfully the standard for the transmission system. The simulation can be reloaded by the user with the information presented in this thesis. Thus, this work can be continued to complete the DAB whole system simulation. The results obtained running this simulation show the main DAB system characteristics.
5
Lum, Randall M. G. "Differential pulse code modulation data compression." Scholarly Commons, 1989. https://scholarlycommons.pacific.edu/uop_etds/2181.
Full textAbstract:
With the requirement to store and transmit information efficiently, an ever increasing number of uses of data compression techniques have been generated in diverse fields such as television, surveillance, remote sensing, medical processing, office automation, and robotics. Rapid increases in processing capabilities and the speed of complex integrated circuits make data compression techniques a prime candidate for application in the areas mentioned above. This report addresses, from a theoretical viewpoint, three major data compression techniques, Pixel Coding, Predictive Coding, and Transform Coding. It begins with a project description and continues with data compression techniques, focusing on Differential Pulse Code Modulation.
6
Xu, Shi-Wen. "Differential modulation of fibroblast properties in scleroderma." Thesis, University College London (University of London), 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.299242.
Full text
7
Yongacoglu, Mustafa Abbas. "On differential detection of digitally modulated signals." Thesis, University of Ottawa (Canada), 1987. http://hdl.handle.net/10393/5113.
Full text
8
Nikolopoulos, Christos. "Mathematical modelling of modulated-temperature differential scanning calorimetry." Thesis, Heriot-Watt University, 1997. http://hdl.handle.net/10399/659.
Full text
9
Jiang, Zhong. "Temperature modulated differential scanning calorimetry : modelling and applications." Thesis, University of Aberdeen, 2000. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU603190.
Full textAbstract:
The research described in this thesis focused on the TMDSC technique with respect to both theoretical problems and applications. Theoretically, modelling work has been performed to address the effects of heat transfer in the measuring cell on both dynamic and quasi-isothermal TMDSC experiments. The problems of heat transfer generally influence the measured complex heat capacity and phase angle values, but eventually affect the precise measurements of other frequency dependent quantities such as the in-phase and out-of-phase heat capacities. A procedure has been suggested to correct the measured phase angle obtained by dynamic TMDSC using the scaled complex heat capacity trace (Chapter 3). The modulation frequency dependence of the instrumental phase angle has been fully investigated using more realistic models in terms of various heat transfer interface qualities, sample properties and sensor properties. In these models, it is emphasised that the measured temperatures are the sensor temperatures rather than the sample temperatures, thus, the contributions of the sensor's properties to the heat transfer are, for the first time, separated from the overall effects (Chapter 4 and Chapter 5). The consequent effects of heat transfer on the sample's heat capacity measurements are investigated based on the models suggested (Chapter 6). All the modelling results are compared with the corresponding experimental data obtained by ADSC (Mettler-Toledo Ltd) and they are in good agreement. Ripples and fluctuations which appear on the experimental signals during the glass transition and cold crystallisation transition have been simulated using* a simple model in which the period of the modulation signals changes with the time during the transitions, and then, been shown to be artefacts of the Fourier transformation process used by TMDSC evaluations (Chapter 7). The applications of TMDSC to both research and commercial samples are reported in terms of differing either the experimental conditions or the thermal history of the sample. Separating of time dependent kinetic processes from the time independent dynamic processes has been applied on the studies of the glass transition (for polycarbonate and poly(ethylene terephthalate)), the cold crystallisation (for poly(ethylene terephthalate)), the melting transition (for poly(ethylene terephthalate) and lead/tin alloys), the clearing transition of a liquid crystal polymer, and the vitrification of an epoxy resin under quasi-isothermal conditions. The main conclusion drawn from these studies is that the in-phase heat capacity is greatly influenced by the frequency of the temperature modulations even when the underlying heating (or cooling) rate remains the same. This strongly implies that the sample undergoes different structural change under different modulation conditions for the melting transition and clearing transition, but not for the glass transition and cold crystallisation. However, the interpretations of the in-phase heat capacity and out-of- phase heat capacity still need to be clarified. The detection of the glass transition and clearing point for the liquid crystal polymers, and the determination of wax appearance temperature for crude oils, show the ability of TMDSC for combining the sensitivity of a measurement at high instantaneous heating or cooling rates with the resolution obtained by measuring at a low underlying heating or cooling rates. The work on the isothermal curing of the epoxy resins displays the ability of TMDSC on measuring the heat capacity of the sample and its variation under the quasi-isothermal conditions. The frequency dependent complex heat capacity during the glass transition provides a window to measure the apparent activation energy of the transition, which is different, in some extent, from the window used by conventional DSC. The results are correlated by a shift factor. Some shortcomings of TMDSC, however, have been noticed in both modelling and application work. Firstly, any experiments for the purpose of either understanding or the quantitative measurements of TMDSC output quantities should be performed under carefully selected conditions which can satisfy the linear response assumption. Secondly, some signals in particular those associated with kinetic processes may not be fully sampled by TMDSC due to the limit of the observing window of a modulation. Thirdly, when the sensitivity is improved on TMDSC by separating the kinetics processes and noises from the dynamic processes, the TMDSC evaluation procedure introduces mathematical artefacts into the output signals. As a consequence, it is preferable to include as many temperature modulations as possible within any transition being studied in order to obtain good quality experimental signals by eliminating or minimising these artefacts, which, however, is not an easy task for some very abrupt transitions such as melting of metals.
10
Noorizadeh, Sahand. "SLM-based Fourier Differential Interference Contrast Microscopy." PDXScholar, 2014. https://pdxscholar.library.pdx.edu/open_access_etds/2011.
Full textAbstract:
Optical phase microscopy provides a view of objects that have minimal to no effect on the detected intensity of light that are unobservable by standard microscopy techniques. Since its inception just over 60 years ago that gave us a vision to an unseen world and earned Frits Zernike the Nobel prize in physics in 1953, phase microscopy has evolved to find various applications in biological cell imaging, crystallography, semiconductor failure analysis, and more. Two common and commercially available techniques are phase contrast and differential interference contrast (DIC). In phase contrast method, a large portion of the unscattered light that accounts for the majority of the light passing unaffected through a transparent medium is blocked to allow the scattered light due to the object to be observed with higher contrast. DIC is a self-referenced interferometer that transduces phase variation to intensity variation. While being established as fundamental tools in many scientific and engineering disciplines, the traditional implementation of these techniques lacks the ability to provide the means for quantitative and repeatable measurement without an extensive and cumbersome calibration. The rapidly growing fields in modern biology meteorology and nano-technology have emphasized the demand for a more robust and convenient quantitative phase microscopy. The recent emergence of modern optical devices such as high resolution programmable spatial light modulators (SLM) has enabled a multitude of research activities over the past decade to reinvent phase microscopy in unconventional ways. This work is concerned with an implementation of a DIC microscope containing a 4-f system at its core with a programmable SLM placed at the frequency plane of the imaging system that allows for employing Fourier pair transforms for wavefront manipulation. This configuration of microscope provides a convenient way to perform both wavefront shearing with quantifiable arbitrary shear amount and direction as well as phase stepping interferometry by programming the SLM with a series of numerically generated patterns and digitally capturing interferograms for each step which are then used to calculate the objects phase gradient map. Wavefront shearing is performed by generating a pattern for the SLM where two phase ramp patterns with opposite slopes are interleaved through a random selection process with uniform distribution in order to mimic the simultaneous presence of the ramps on the same plane. The theoretical treatment accompanied by simulations and experimental results and discussion are presented in this work.
11
Lunel, Simon. "Parallelism and modular proof in differential dynamic logic." Thesis, Rennes 1, 2019. http://www.theses.fr/2019REN1S005/document.
Full textAbstract:
Les systèmes cyber-physiques mélangent des comportements physiques continus, tel la vitesse d'un véhicule, et des comportement discrets, tel que le régulateur de vitesse d'un véhicule. Ils sont désormais omniprésents dans notre société. Un grand nombre de ces systèmes sont dits critiques, i.e. une mauvaise conception entraînant un comportement non prévu, un bug, peut mettre en danger des êtres humains. Il est nécessaire de développer des méthodes pour garantir le bon fonctionnement de tels systèmes. Les méthodes formelles regroupent des procédés mathématiques pour garantir qu'un système se comporte comme attendu, par exemple que le régulateur de vitesse n'autorise pas de dépasser la vitesse maximale autorisée. De récents travaux ont permis des progrès significatifs dans ce domaine, mais l'approche adoptée est encore monolithique, i.e. que le système est modélisé d'un seul tenant et est ensuite soumis à la preuve. Notre problématique est comment modéliser efficacement des systèmes cyber-physiques dont la complexité réside dans une répétition de morceaux élémentaires. Et une fois que l'on a obtenu une modélisation, comment garantir le bon fonctionnement de tels systèmes. Notre approche consiste à modéliser le système de manière compositionnelle. Plutôt que de vouloir le modéliser d'un seul tenant, il faut le faire morceaux par morceaux, appelés composants. Chaque composant correspond à un sous-système du système final qu'il est simple de modéliser. On obtient le système complet en assemblant les composants ensembles. Ainsi une usine de traitement des eaux est obtenue en assemblant différentes cuves. L'intérêt de cette méthode est qu'elle correspond à l'approche des ingénieurs dans l'industrie : considérer des éléments séparés que l'on compose ensuite. Mais cette approche seule ne résout pas le problème de la preuve de bon fonctionnement du système. Il faut aussi rendre la preuve compositionnelle. Pour cela, on associe à chaque composant des propriétés sur ses entrées et sortie, et on prouve qu'elles sont respectées. Cette preuve peut être effectué par un expert, mais aussi par un ordinateur si les composants sont de tailles raisonnables. Il faut ensuite nous assurer que lors de l'assemblage des composants, les propriétés continuent à être respectées. Ainsi, la charge de la preuve est reportée sur les composants élémentaires, l'assurance du respect des propriétés désirées est conservée lors des étapes de composition. On peut alors obtenir une preuve du bon fonctionnement de systèmes industriels avec un coût de preuve réduit. Notre contribution majeure est de proposer une telle approche compositionnelle à la fois pour modéliser des systèmes cyber-physiques, mais aussi pour prouver qu'ils respectent les propriétés voulues. Ainsi, à chaque étape de la conception, on s'assure que les propriétés sont conservées, si possible à l'aide d'un ordinateur. Le système résultant est correct par construction. De ce résultat, nous avons proposé plusieurs outils pour aider à la conception de systèmes cyber-physiques de manière modulaire. On peut raisonner sur les propriétés temporelles de tels systèmes, par exemple est-ce que le temps de réaction d'un contrôleur est suffisamment court pour garantir le bon fonctionnement. On peut aussi raisonner sur des systèmes où un mode nominal cohabite avec un mode d'urgenceCyber-physical systems mix continuous physical behaviors, e.g. the velocity of a vehicle, and discrete behaviors, e.g. the cruise-controller of the vehicle. They are pervasive in our society. Numerous of such systems are safety-critical, i.e. a design error which leads to an unexpected behavior can harm humans. It is mandatory to develop methods to ensure the correct functioning of such systems. Formal methods is a set of mathematical methods that are used to guarantee that a system behaves as expected, e.g. that the cruise-controller does not allow the vehicle to exceed the speed limit. Recent works have allowed significant progress in the domain of the verification of cyber-physical systems, but the approach is still monolithic. The system under consideration is modeled in one block. Our problematic is how to efficiently model cyber-physical systems where the complexity lies in a repetition of elementary blocks. And once this modeling done, how guaranteeing the correct functioning of such systems. Our approach is to model the system in a compositional manner. Rather than modeling it in one block, we model it pieces by pieces, called components. Each component correspond to a subsystem of the final system and are easier to model due to their reasonable size. We obtain the complete system by assembling the different components. A water-plant will thus be obtained by the composition of several water-tanks. The main advantage of this method is that it corresponds to the work-flow in the industry : consider each elements separately and compose them later. But this approach does not solve the problem of the proof of correct functioning of the system. We have to make the proof compositional too. To achieve it, we associate to each component properties on its inputs and outputs, then prove that they are satisfied. This step can be done by a domain expert, but also by a computer program if the component is of a reasonable size. We have then to ensure that the properties are preserved through the composition. Thus, the proof effort is reported to elementary components. It is possible to obtain a proof of the correct functioning of industrial systems with a reduced proof effort. Our main contribution is the development of such approach in Differential Dynamic Logic. We are able to modularly model cyber-physical systems, but also prove their correct functioning. Then, at each stage of the design, we can verify that the desired properties are still guaranteed. The resulting system is correct-by-construction. From this result, we have developed several tools to help for the modular reasoning on cyber-physical systems. We have proposed a methodology to reason on temporal properties, e.g. if the execution period of a controller is small enough to effectively regulate the continuous behavior. We have also showed how we can reason on functioning modes in our framework
12
Himsoon, Thanongsak. "Differential modulation for broadband space-time/cooperative wireless communications." College Park, Md. : University of Maryland, 2006. http://hdl.handle.net/1903/3984.
Full textAbstract:
Thesis (Ph. D.) -- University of Maryland, College Park, 2006.Thesis research directed by: Electrical Engineering. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
13
Lu, Wei-Ting. "Modulation of Fanconi Anaemia pathway in terminally differential cells." Thesis, University of Sheffield, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.531092.
Full text
14
Sims-Robinson, Catrina Suppiramaniam Vishnu. "Differential modulation of glutamatergic synaptic transmission by polysialic acid." Auburn, Ala, 2007. http://hdl.handle.net/10415/1352.
Full text
15
Liu, Zhiping. "Differential mucosal gene expression modulates the development of murine colitis." [Ames, Iowa : Iowa State University], 2008.
Find full text
16
Collaer, Marcia Lee. "IMAGE DATA COMPRESSION: DIFFERENTIAL PULSE CODE MODULATION OF TOMOGRAPHIC PROJECTIONS." Thesis, The University of Arizona, 1985. http://hdl.handle.net/10150/291412.
Full text
17
Ma, Kuang-Hua. "Image compression using a double differential pulse code modulation technique (DPCM/DPCM." Ohio : Ohio University, 1996. http://www.ohiolink.edu/etd/view.cgi?ohiou1178215120.
Full text
18
Ma, Yongteng 1974. "Multiple-symbol differential detection for differential space-time modulation in the presence of multiple cochannel interferers : Yongteng Ma." Thesis, McGill University, 2006. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=98994.
Full textAbstract:
Space-time coding and modulation employ multiple transmit and receive antennas to improve performance over multipath fading channels. In most works on space-time coding, perfect channel state information is assumed to be available at the receiver. In many practical situations, however, it may be difficult or costly to accurately estimate the channel. In this thesis, a multiple-symbol differential detector is derived for dicyclic unitary group codes for differential space-time modulation in the presence of multiple uncorrelated equal-power cochannel interferers over a slow-fading Rayleigh channel that is unknown to the transmitter and the receiver. The covariance matrix of the interference plus noise is assumed to be known at the receiver. Under the Gaussian assumption for the aggregate interference plus noise, the maximurn-likelihood decision statistic is developed for the detector. Its pairwise error probability and bit error probability performance is evaluated by analysis and demonstrated by simulation. It is shown that the detector can efficiently suppress cochannel interference, and with an increase in observation interval, the performance of multiple-symbol differential detection approaches that of coherent detection with differential encoding and ideal channel information.
19
Spenler, Stephen John. "Differentially coherent trellis coded modulation with subset dilation." Thesis, University of Ottawa (Canada), 1989. http://hdl.handle.net/10393/5963.
Full text
20
Song, Mo. "Applications of modulated-temperature differential scanning calorimetry to multi-component polymer materials." Thesis, Lancaster University, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.337256.
Full text
21
Wong, K. H. J. "Adaptive differential pulse code modulation and sub-band coding of speech signals." Thesis, University of Southampton, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.380170.
Full text
22
Yoshida, K. "Speech coding by adaptive differential pulse code modulation with adaptive bit allocation." Thesis, Imperial College London, 1985. http://hdl.handle.net/10044/1/37905.
Full text
23
McGlone, Sarah T. "Affective Modulation of Nociception in Individuals at Differential Risk for Developing Hypertension." Ohio University / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1248811754.
Full text
24
Mano, Toshiyuki. "Differential equations for Hilbert modular forms of Q([square root]{2})." 京都大学 (Kyoto University), 2002. http://hdl.handle.net/2433/150419.
Full text
25
Liu, Yang. "Modular curvature for toric noncommutative manifolds." The Ohio State University, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=osu1440121460.
Full text
26
Vidyarthi, Ananta. "Digital AM Radio Navigation using differential Time Difference of Arrival Principle." University of Cincinnati / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1336762773.
Full text
27
Cooperwood, Michael Vonshay. "Analysis and performance comparison of adaptive differential pulse code modulation data compression systems." Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1996. http://handle.dtic.mil/100.2/ADA307823.
Full text
28
Basil, Peter G. "Real-time multi-frequency modulation using differentially-encoded signal constellations." Thesis, Monterey, California : Naval Postgraduate School, 1990. http://handle.dtic.mil/100.2/ADA236839.
Full textAbstract:
Thesis (M.S. in Electrical Engineering)--Naval Postgraduate School, June 1990.Thesis Advisor(s): Moose, P. H. Second Reader: Terman, F. W. "June 1990." Description based on title screen as viewed on October 19, 2009. DTIC Descriptor(s): Signal processing, input, control, industries, real time, computers, signal to noise ratio, rates, coding, receivers, errors, data acquisition, vector analysis, throughput, microcomputers, data rate, modulation, data processing equipment, decoding, plug in units, frequency DTIC Indicator(s): Packet communications, frequency modulation, program listings, signal to noise ratio. Author(s) subject terms: MFM, Differential encoding, D16QAM Includes bibliographical references (p. 68). Also available in print.
29
Hildebrand, Michael Earl. "Differential modulation of T-type voltage gated calcium channels by G-protein coupled receptors." Thesis, University of British Columbia, 2008. http://hdl.handle.net/2429/1019.
Full textAbstract:
T-type voltage-gated calcium (Ca2+) channels play critical roles in controlling neuronal excitability, firing patterns, and synaptic plasticity, although the mechanisms and extent to which T-type Ca2+ channels are modulated by G-protein coupled receptors (GPCRs) remains largely unexplored. Investigations into T-type modulation within native neuronal systems have been complicated by the presence of multiple GPCR subtypes and a lack of pharmacological tools to separate currents generated by the three T-type isoforms; Cav3.1, Cav3.2, and Cav3.3. We hypothesize that specific Cav3 subtypes play unique roles in neuronal physiology due to their differential functional coupling to specific GPCRs.
Co-expression of T-type channel subtypes and GPCRs in a heterologous system allowed us to identify the specific interactions between muscarinic acetylcholine (mAChR) or metabotropic glutamate (mGluR) GPCRs and individual Cav3 isoforms. Perforated patch recordings demonstrated that activation of Galpha-coupled GPCRs had a strong inhibitory effect on Cav3.3 T-type Ca2+ currents but either no effect or a stimulating effect on Cav3.1 and Cav3.2 peak current amplitudes. Further study of the inhibition of Cav3.3 channels by a specific Galpha-coupled mAChR (M1) revealed that this reversible inhibition was associated with a concomitant increase in inactivation kinetics. Pharmacological and genetic experiments indicated that the M1 receptor-mediated inhibition of Cav3.3 occurs specifically through a Galphasignaling pathway that interacts with two distinct regions of the Cav3.3 channel. As hypothesized, the potentiation of Cav3.1 channels by a Galpha-coupled mGluR (mGluR1) initially characterized in the heterologous system was also observed in a native neuronal system: the cerebellar Purkinje cell (PC). In recordings on PCs within acute cerebellar slices, we demonstrated that the potentiation of Cav3.1 currents by mGluR1 activation is strongest near the threshold of T-type currents, enhancing the excitability of PCs. Ultrafast two-photon Ca2+ imaging demonstrated that the functional coupling between mGluR1 and T-type transients occurs within dendritic spines, where synaptic integration and plasticity occurs. A subset of these experiments utilized physiological synaptic activation and specific mGluR1 antagonists in wild-type and Cav3.1 knock-out mice to show that the mGluR1-mediated potentiation of Cav3.1 T-type currents may promote synapse-specific Ca2+ signaling in response to bursts of excitatory inputs.
30
Boudreau, Daniel Carleton University Dissertation Engineering Electrical. "The application of feedback decoding in the differential detection of continuous phase modulated signals." Ottawa, 1987.
Find full text
31
Xiang, Dong. "Differential dielectric sensor analysis and experimental investigation of a modular differential dielectric sensor for use in multiphase separation, process measurement and control." Saarbrücken VDM Verlag Dr. Müller, 2008. http://d-nb.info/991258150/04.
Full text
32
Rogers, Jeffrey L. "Modulated pattern formation : stabilization, complex-order, and symmetry." Diss., Georgia Institute of Technology, 2001. http://hdl.handle.net/1853/30930.
Full text
33
Peddie, Matthew. "Odd Poisson supermanifolds, Courant algebroids, homotopy structures, and differential operators." Thesis, University of Manchester, 2017. https://www.research.manchester.ac.uk/portal/en/theses/odd-poisson-supermanifolds-courant-algebroids-homotopy-structures-and-differential-operators(7eb317c0-7584-4c17-81d9-d9958ca47af2).html.
Full textAbstract:
In this thesis we investigate the role of odd Poisson brackets in related areas of supergeometry. In particular we study three different cases of their appearance: Courant algebroids and their homotopy analogues, weak Poisson structures and their relation to foliated manifolds, and the structure of odd Poisson manifolds and their modular class. In chapter 2 we introduce the notion of a homotopy Courant algebroid, a subclass of which is suggested to stand as the double objects to L-bialgebroids. We provide explicit formula for the higher homotopy Dorfman brackets introduced in this case, and the higher relations between these and the anchor maps. The homotopy Loday structure is investigated, and we begin a discussion of what other constructions in the theory of Courant algebroids can be carried out in this homotopy setting. Chapter 3 is devoted to lifting a weak Poisson structure corresponding to a local foliation of a submanifold to a weak Koszul bracket, and interpreting the results in terms of the cohomology of an associated differential. This bracket is shown to produce a bracket on co-exact differential forms. In chapter 5 studies classes of second order differential operators acting on semidensities on an arbitrary supermanifold. In particular, when the supermanifold is odd Poisson, we given an explicit description of the modular class of the odd Poisson manifold, and provide the first non-trivial examples of such a class. We also introduce the potential field of a general odd Laplacian, and discuss its relation to the geometry of the odd Poisson manifold and its status as a connection-like object.
34
Meesawatsom, Pongsatorn. "Differential modulation of spinal nociceptive processing by aspirin-triggered resolvin D1 in rat pain models." Thesis, University of Nottingham, 2018. http://eprints.nottingham.ac.uk/52364/.
Full textAbstract:
Harnessing the actions of the resolvin pathways has the potential for the treatment of a wide-range of conditions associated with overt inflammatory signalling. Aspirin-triggered resolvin D1 (AT-RvD1) is a potent anti-inflammatory lipid derived from docosahexaenoic acid (DHA). In rodent, the biological effects of AT-RvD1 are mainly mediated by its specific G-protein coupled receptor, formyl peptide receptor 2 (ALX/FPR2). AT-RvD1 has been demonstrated potent anti-inflammatory and tissue resolution promoting (pro-resolving) activities in preclinical model of inflammatory diseases. Continuous peripheral activity of nociceptive fibres induces neuroinflammatory responses and alters the excitability neurones in both peripheral and central pain pathways. This thesis focused on spinal neuroinflammation which plays important roles in the sensitisation of nociceptive processing of the spinal dorsal horn neurones and contributes to the nociceptive hypersensitivity of the central pain pathway in acute and chronic pain. Since AT-RvD1 possess a potent anti-inflammatory activity, therefore, enhancing AT-RvD1 signalling in the spinal cord may attenuate the spinal nociceptive sensitisation and provide analgesia. AT-RvD1 also has robust antinociceptive effects in behavioural models of pain, however the potential underlying spinal neurophysiological mechanisms contributing to these inhibitory effects in vivo are yet to be determined. The purposes of this thesis were to investigate the differential effects of spinal AT-RvD1 on evoked responses of spinal neurones in vivo in well characterised pain models include carrageenan-induced acute inflammatory pain, monosodium iodoacetate (MIA)-induced OA pain and paclitaxel (PCX)-induced peripheral neuropathic pain and to investigate the alterations in the expression of spinal genes relevant to the resolvin system and neuroinflammation that may underlie the differential effects of AT-RvD1 among these pain models. Following model induction, pain behaviour was assessed and then rats were prepared for single unit extracellular recordings of dorsal horn wide dynamic range (WDR) neurones on the following day post carrageenan or day 28-32 post MIA or PCX induction. At the time-matched the spinal recording, ipsilateral dorsal quadrants of spinal cord form separate groups of rats were collected for gene expression quantification using TaqMan Low Density Arrays (TLDA). AT-RvD1 clearly demonstrated differential inhibition on evoked responses of WDR neurones in the pain models of interest. Low dose AT-RvD1 (15 ng/50ul) selectively produced a robust inhibition of electrical-evoked responses (Adelta-, C-fibre, post-discharge, input, wind-up) of WDR neurones in carrageenan rats but not in control rats. These effects were abolished by spinal pre-administration of a FPR2/ALX antagonist, butoxy carbonyl-Phe-Leu-Phe-Leu-Phe (BOC-2) (50 ug/50ul). In MIA rats, AT-RvD1 given at a high dose (150 ng/50ul) produced only mild inhibition of electrical evoked Adelta responses but not at a low dose (15 ng/50ul). AT-RvD1 (15 and 150 ng/50ul) had no significant effects on electrical evoked responses of PCX rat WDR neurones. Interestingly, AT-RvD1 produced a dose dependent and selective inhibition of low intensity mechanical evoked responses PCX rats whereas it had no effects in control rats. At high dose (150 ng/50ul), the magnitude of inhibition of 8g mechanical evoked responses was comparable to morphine (1 ug/50ul) applied at the end of the experiments. AT-RvD1 produced a dose dependent inhibition of acetone-evoked responses in PCX rats, however WDR neurones in the control rats were also inhibited to a similar degree. TLDA revealed the distinct alteration of resolvin genes in spinal cord underpinning the differential inhibition of AT-TvD1. Upregulated 5-lipoxygenase activating protein (FLAP) gene, encoding protein determining endogenous resolvin synthesis, in carrageenan and PCX rats may underlie the robust inhibition of AT-RvD1 on WDR neurones in these two models. The minimal effects AT-RvD1 of MIA rats were associated with upregulated 15-hydroxyprostaglandin dehydrogenase (15-HPGD) gene, encoding a major enzyme responsible for D-series resolvin inactivation. Data presented in this thesis provide for the first time the differential inhibition of AT-RvD1 on spinal nociceptive processing in different types of pain and the evidence of heterogeneous spinal alterations of the resolvin signalling potentially underlie such inhibition. This thesis strongly supports further investigation of AT-RvD1 as a novel analgesic. Another part of this thesis demonstrated changes in the responses of spinal WDR neurones in PCX rats. Spinal WDR neurones from PCX rats displayed characteristics representing pain sensitisation including: reduced the thresholds for Abeta and C-fibre responses; increased proportion of neurones exhibiting spontaneous activity, acetone responsiveness and post-discharge following low intensity mechanical stimuli and a more convergence in stimulus processing. A remarkable upregulation of multiple genes in proinflammatory signallings, toll-liked receptor 4 (Tlr4), interleukin-1 (Nlrp1a) and tumour necrosis factor-alpha receptors (Tnfrsf1a and Tnfrsf1b) and chemokines (Cxcl6, Cxcr1, Cxcr5, Ccr1, Cx3cr1), was found in the spinal cord of PCX rats. This suggests that a high inflammatory component in the spinal cord could contribute to the changes in the responses of spinal WDR neurones in the PCX rats. This thesis supports further investigation of targeting neuroinflammation as a promising approach for the treatment of PCX-induced neuropathic pain.
35
Krüger, Helena. "A calibration neutron monitor for long-term cosmic ray modulation studies / H. Krüger." Thesis, North-West University, 2006. http://hdl.handle.net/10394/1023.
Full textAbstract:
The propagation of high-energy cosmic rays is influenced by the time-varying heliospheric
magnetic field embedded in the solar wind, and by the geomagnetic field. To penetrate
through this geomagnetic field, they must have a rigidity that exceeds the geomagnetic cutoff
rigidity for a given position on the earth. In the atmosphere, the primary cosmic rays interact
with atmospheric nuclei, to form a cascade of secondary particles. Neutron monitors record
these secondary cosmic rays, mainly the neutrons, with energies about a decade higher than
detected by most spacecraft.
Since neutron monitors are integral detectors, each with its own detection efficiency, energy
spectra cannot readily be derived from their observations. One way to circumvent this is by
conducting latitudinal surveys with mobile neutron monitors. Another way is to use the
worldwide stationary neutron monitor network, but then the counting rates of these monitors
must be normalised sufficiently accurate against one another. For this reason two portable
calibration neutron monitors were built at the Potchefstroom campus of the North-West
University and completed in 2002.
To achieve sufficient calibration accuracy, several properties of the calibrator are
investigated in this work. Effects such as atmospheric pressure variations, diurnal variations,
short-term scintillations, and multiplicity, contribute to the fluctuations of the counting rate of a
neutron monitor. Due to these effects, the coefficient of variation of the calibrator is
determined to be -40% larger than the Poisson deviation. The energy response of the
calibrator over the cutoff rigidity interval from the poles to the equator is investigated, with the
result that it is almost 4% larger than that of a standard 3NM64 neutron monitor. It is also
determined that not only the calibrator, but also the stationary NM64 and IGY neutron
monitors, have fairly large instrumental temperature sensitivity, which must be accounted for
in calibration procedures. Furthermore, the calibrator has a large sensitivity to the type of
surface beneath it, influencing its counting rate by as much as 5%. This investigation is
incomplete and requires further experimentation before the calibration of the stationary
neutron monitors can start.
When calibrations of a significant number of the worldwide neutron monitors are done, their
intensity spectra as derived from differential response functions, will provide experimental
data for modulation studies at rigidities above 1 GV.Thesis (Ph.D. (Physics))--North-West University, Potchefstroom Campus, 2006.
36
Xue, Feng. "Specific ECM Engagement Differentially Modulates T Cell Cytoskeletal Reorganization By Rho GTPases." Case Western Reserve University School of Graduate Studies / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=case1221770198.
Full text
37
Kuipa, Michael. "Antiretroviral drugs differentially modulate glucocorticoid activity via the glucocorticoid receptor in vitro." Master's thesis, Faculty of Science, 2019. http://hdl.handle.net/11427/31426.
Full textAbstract:
Concurrent use of anti-retroviral drugs (ARVs) and progestin-based hormonal contraceptives is widespread. During times of stress and during glucocorticoid (GC) therapy, intracellular ARVs are in the presence of high concentrations of GCs, which regulate all aspects of immunity and inflammation via the glucocorticoid receptor (GR). However, the reciprocal modulation of ARV and steroid intracellular functions is relatively unexplored. In this study, the effects of the ARVs tenofovir disoproxil fumarate (TDF), dapivirine (DPV), and maraviroc (MVC) on activation of the GR and GR-regulated mRNA expression were investigated, in the absence and presence of select GR ligands. The effects of TDF and DPV on GR protein levels and phosphorylation were also determined. The inhibitory activity of these ARVs on HIV-1 infection in the presence of the progestins medroxyprogesterone acetate (MPA) and levonorgestrel (LNG), and a GR agonist, dexamethasone (DEX) was also assessed. This study shows that (0.01 nM-10 µM) TDF, DPV and MVC do not transactivate reporter gene expression via the unliganded GR exogenously expressed in the steroid receptor-deficient U2OS human osteosarcoma cell line, or alter the reporter gene transcriptional activity of (100 nM) MPA or LNG via the GR in these cells. However, (1 µM) TDF and DPV modulate the reporter gene transcriptional efficacy of (0.01 nM-10 µM) DEX via the GR. In the U2OS cell line model, (1 µM) TDF, but not DPV significantly decreased (1µM and 10µM) DEX-induced mRNA expression of the anti-inflammatory glucocorticoid-induced leucine zipper (GILZ) gene. TDF also appeared to decrease (1 µM) cortisol (CORT)- and MPA-induced GILZ mRNA expression. This may be mediated by the apparent increase in (100 nM and 1µM) DEXinduced phosphorylation at Serine 226 on the GR, observed in the presence of (1µM) TDF in this study. DPV and TDF (at 1µM) did not significantly alter GR protein levels, or cell-viability in the absence and presence of (100 nM) DEX, CORT or MPA in U2OS cells. However, (1 µM) DPV and TDF alone, significantly altered cell viability in peripheral blood mononuclear cells (PBMCs). In PBMCs, (1 µM) TDF, MVC and DPV alone altered basal GILZ mRNA expression and had variable, donor-specific effects on interleukin (IL)-6, IL-8, and interferon (IFN)-γ gene expression. In PBMCs from some of the nine donors tested, these ARVs had proinflammatory effects which may undermine their efficacy at preventing HIV-1 acquisition in pre-exposure prophylaxis products. Moreover, the ARVs proinflammatory effects may negatively impact HIV-1 disease progression and increase the risk of non-AIDS mortality in individuals using the ARVs therapeutically. Neither (1 µM) DPV, TDF nor MVC significantly altered the effects of (100 nM) DEX on the immunomodulatory genes assessed in PBMCs. DEX, MPA and LNG (at 100 nM) did not affect the anti-HIV-1 activity of the ARVs (at 1 µM) in PBMCs from the majority of the three donors tested in this study. Taken together, the results show that ARVs can modulate GR activity in an ARV-, steroid-, gene- and cell-specific manner, while the steroids investigated did not modulate ARV anti-HIV-1 activity.
38
Mendelson, Scott Douglas. "Differential roles of serotonin receptor subtypes in the modulation of lordosis behaviour in the female rat." Thesis, University of British Columbia, 1988. http://hdl.handle.net/2429/29021.
Full textAbstract:
In 1985, Mendelson and Gorzalka proposed the dual role hypothesis of serotonergic modulation of lordosis behaviour. In this hypothesis it was proposed that serotonergic activity can either inhibit or facilitate lordosis behaviour. Specifically it was suggested that the lordosis-inhibiting effects of serotonin are mediated by activity at 5-HT₁ receptors, whereas lordosis-facilitating effects of serotonin are mediated by activity at 5-HT₂ receptors. The purpose of the following series of studies was both to confirm and to extend the dual role hypothesis. The intraperitoneal administration of the 5-HT2 antagonists pizotefin (1 mg/kg), cyproheptadine (1 mg/kg), metitepine (1 mg/kg), and ketanserin (1 mg/kg) were found to inhibit lordosis behavior in ovariectomized rats that had been primed with estradiol benzoate (EB) and progesterone (P). Pipamperone was ineffective. The 5-HT₂ agonist guipazine (3 mg/kg) was ineffective alone, but it reversed the inhibitory effects of pizotefin, cyproheptadine, and ketanserin. It did not reverse the effects of metitepine. The highly selective 5-HT₂ antagonist LY53857 (0.3 mg/kg) was also found to inhibit lordosis behaviour in female rats that had been primed with EB and P. The lordosis-inhibiting effect of LY53857 (1 mg/kg) in females primed with EB and P was reversed by quipazine (3 mg/kg). The nonselective 5-HT antagonist methysergide (7 mg/kg) was found to inhibit lordosis behavior 30 min after intraperitoneal administration to females treated chronically with EB, or with EB and P. However, methysergide was found to facilitate lordosis behavior 200 and 300 min after administration to female rats treated acutely with EB. In an analysis of dose response it was found that methysergide (0.02 - 7 mg/kg) administered 30 min prior to behavioural testing produced no facilitation of lordosis in females primed with EB. However, when administered 200 min prior to testing, methysergide (1 mg/kg) produced a significant facilitation of lordosis.
The administration of the 5-HT₁ A agonist 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH DPAT) inhibited lordosis behavior in ovariectomized rats primed with EB. 8-OH DPAT was ineffective at 0.01 mg/kg, whereas inhibition occurred at the 0.03, 0.1, 0.3, 1.0, and 3.0 mg/kg doses. In an evaluation of the effects of 8-OH DPAT on the expression of male sexual behaviour by females treated chronically with testosterone, 8-OH DPAT ( 1 mg/kg) increased the number of females mounting and significantly increased mount frequency. The 5-HT₁ A agonists ipsapirone (0.1 mg/kg) and gepirone (0.3 mg/kg) facilitated lordosis in females treated with EB. When administered at higher doses, ipsapirone (3.0 mg/kg) and buspirone (3.0 mg/kg) inhibited lordosis in rats treated with EB. In females treated with EB and P, ipsapirone (> 1.0 mg/kg), gepirone (> 0.3), and buspirone (> 0.3) inhibited lordosis behaviour. The newly developed 5-HT₁ A antagonist BMY 7378 (0.2 mg/kg) facilitated lordosis behaviour in females treated with EB. However, this facilitation was no longer apparent at the 5 mg/kg dose. BMY 7378 (0.04 - 5 mg/kg) was ineffective in females primed with EB and P. The 5-HTTB agonist 1 -(3-trifluoromethylphenyl)piperazine (TFMPP, 0.2 -5 mg/kg) was found to facilitate lordosis in females treated with EB. In females primed with EB and P, TFMPP (5 mg/kg) produced a significant inhibition of lordosis. The 5-HT₁ B agonist m-chlorophenylpiperazine (MCPP, 0.04 - 5 mg/kg) was ineffective in females primed either with EB or with EB and P.
The 5-HT₃ Antagonist ICS 205-930 (5 mg/kg) was found to facilitate lordosis behaviour, whereas the 5-HT₃ Antagonist MDL 72222 (0.05 - 5 mg/kg ) was found to be ineffective in females primed with EB.
The results of these studies tend to confirm that serotonergic activity can either inhibit or facilitate lordosis behaviour. It is suggested that the lordosis-inhibiting effects of serotonin are mediated by activity at postsynaptic 5-HTTA and possibly 5-HT₃ Receptors. The lordosis-facilitating effects of serotonin are mediated by activity at 5-HT₂ and possibly presynaptic 5-HT₁ B receptors. Finally, it is suggested that activity at somato-dendritic 5-HT₁ A autoreceptors may mediate facilitatory effects of low doses of 5-HT₁ A agonists. In closing, there is a discussion of the implications these results might hold for the understanding of the effects of serotonergic drugs on human behaviour.Arts, Faculty of
Psychology, Department of
Graduate
39
Paiement, Richard V. "The study of differential 8-PSK trellis-coded modulation in indoor wireless communications through computer simulation." Thesis, University of Ottawa (Canada), 1991. http://hdl.handle.net/10393/7641.
Full textAbstract:
This thesis work studies the use of 4- and 8-state trellis-coded modulation with phase-shift keying and non-coherent, differential signaling for digital indoor wireless communications, at an operating frequency of 1.5 GHz and a transmission rate of 10 Mbits/s. Many other modulation schemes have been considered for the indoor wireless channel in other studies, and trellis-coded modulation has been considered for the satellite and mobile channel. This study presents new BER performance results, obtained through computer simulations, that suggest a performance gain with TCM relative to DQPSK, for certain ranges of SNR and rms delay spread. Equalization is also considered, and it is shown that it can provide considerable performance gain.
40
Umar, Muhammad, and Umar Yasir. "Differential Six-Port Transceiver Design and Analysis from a Wireless Communication System Perspective." Thesis, Linköpings universitet, Institutionen för teknik och naturvetenskap, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-78943.
Full textAbstract:
In modern telecommunication there is the demand of high data rates using wideband component design. FCC has introduced the UWB spectrum for high speed data communication. UWB systems have attracted the attention of researchers. Six-port transmitters and receivers are strong candidates for UWB systems and research is being done on six-port modulators and demodulators. In this work an effort is made to compare the performance of conventional single-ended six-port transmitter and receiver with differential six-port transmitters and receivers. In this thesis, single ended and differential six-port correlators are designed on 7.5 GHz using Agilent Inc. EDA tool ADS and their performance is evaluated. A new wide-band differential six-port correlator is implemented using rat-race couplers and double-sided parallel strip-line phase inverter. The designed six-port correlators are used for 8-PSK modulation and demodulation. For transmitter-receiver system, mixed analog-DSP designing is used. The integral components of the system are evaluated individually and behavioral modeling is used to evaluate the complete transmitter-receiver system. The single-ended and differential systems are evaluated for noise-figure, dynamic range, bit error rate and data rate.
41
Dahan, Albert. "Receptor binding of somatostatin-14 and somatostatin-28 in rat brain differential modulation by nucleotides and ions." Thesis, McGill University, 1986. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=66121.
Full text
42
Clark, Tobias Samuel Thomas. "Monoamines Differentially Modulate Neuropeptide Release from Distinct Sites Within A Single Neuron Pair." University of Toledo / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1532803532438522.
Full text
43
Ottery, Peter. "Using differential adhesion to control self-assembly and self-repair of collections of modular mobile robots." Thesis, University of Edinburgh, 2006. http://hdl.handle.net/1842/1396.
Full textAbstract:
This thesis presents a novel distributed control method which allows a collection of independently mobile robotic units, with two or three dimensional movement, to self-assemble into self-repairing hierarchical structures. The proposed method utilises a simple model of the cellular adhesion mechanisms observed in biological cells, allowing the robotic units to form virtually bonded aggregates which behave as predicted by Steinberg’s differential adhesion hypothesis. Simulated robotic units based on the design of the subaquatic HYDRON module are introduced as a possible platform on which the model can be implemented. The units are used to carry out a detailed investigation of the model behaviour and parameter space focusing on the two main tasks of rounding and sorting in both two and three dimensions. These tasks assess the model’s ability to reach a thermodynamically stable configuration when the aggregates consist of either a single population of units or multiple populations of units with differing adhesive properties. The results are analysed in detail with particular attention given to the role of random movements in determining the overall performance, and demonstrate that this model provides a very robust solution to these complex tasks. Finally, a possible extension of this work is presented in which the original model is combined with a genetic regulatory network controller. The performance of this composite is evaluated, and the benefits of this hybrid approach, in which a powerful control system manipulates a robust self-organising behaviour, are discussed.
44
Khan, M. R. "The differential modulation of receptor tyrosine kinase Axl in human mesenchymal stromal cell responses to modified titanium surfaces." Thesis, University College London (University of London), 2012. http://discovery.ucl.ac.uk/1346458/.
Full textAbstract:
Osseointegration is the process of de novo bone regeneration on the surface of an endosseous titanium (Ti) implant in vivo. This neo formation of bone underlies the physical integration of a Ti implant in bone at a level sufficient to restore loss of function; for example, of mastication due to absent teeth. The outer atoms of a bulk of Ti metal form a stable and passive surface oxide layer that serves as a substrate for the amalgamation of tissue reparative components, which entail the formation of an osseous bond between tissue and fixture. This interaction was empirically demonstrated to be highly affected by the characteristics of the surface an implant in experimental studies querying the varied effects of additive or subtractive physical modifications, as well as altered chemical compositions, of Ti implant surfaces on osseointegration. Subsequent clinical and experimental practices have demonstrated that rough surfaced implants perform comparatively ‘better’ than their smooth surfaced counterparts by promoting bone growth on the fixture. Moreover, a particular surface modification that yields high surface energy combined with a widely tested micron scaled topographical roughness (modSLA) has been shown to further promote the timely enhancement of osseointegration compared to its hydrophobic rough counterpart (SLA). The biological mechanisms underlying this apparent enhancement of osseointegration by modified Ti implant surfaces are still subject to intense study due to the materials’ implications in bone related tissue engineering applications. Amongst the several views being opined is a proposition mainly arising from in vitro experimentation, which suggests modified Ti implant surfaces possess an ‘intrinsic’ osteoinductive potential that affects uncommitted reparative cells by inducing a temporal and magnitudinal enhancement in cellular differentiation and function; in turn, implying the early formation of functional osteoblasts and bone tissue matrix in an in vivo scenario. The observations of differential cellular behavior include the apparent modulation by the modified surfaces, of a cell surface receptor tyrosine kinase Axl in human osteoblasts. The proposed role of the receptor in negatively regulating osteogenic mineralisation in uncommitted pericytic cells suggests an association with the altered response of cells to these substrates. The aim of this project was to examine and test the hypothesised differential modulation of Axl in the responses of human marrow derived mesenchymal stromal cells to modified Ti implant substrates.
45
Seo, Jeongmin. "Docosahexaenoic acid differentially modulates plasma membrane targeting and subcellular localization of lipidated proteins in colonocytes." Texas A&M University, 2004. http://hdl.handle.net/1969.1/3258.
Full textAbstract:
Correct localization of lipidated cytosolic proteins to the plasma membrane (PM) is mediated by interactions between lipid anchors of proteins and cell membranes. Previously, dietary fish oil and its major n-3 polyunsaturated fatty acid (PUFA), docosahexaenoic acid (DHA), have been shown to decrease Ras membrane association, concomitantly reducing rat colon tumor incidence and Ras signaling, compared with corn oil and linoleic acid (LA), a highly prevalent vegetable fat and dietary PUFA in the U.S. diet. In order to explore the potential regulatory role of the cellular lipid environment in PM targeting of lipidated proteins, young adult mouse colon (YAMC) cells were treated with 50 µM DHA, LA, or oleic acid (OA) 24 h prior to and 36-48 h after transfection with green fluorescent protein (GFP) fusion constructs of various lipidated cytosolic proteins. Relative expression of each GFP fusion protein at the PM and the Golgi in living cells was quantified using z-serial confocal microscopy and digital image processing. DHA differentially altered the subcellular localization of Ras isoforms and Src-related tyrosine kinases in a reversible manner. DHA significantly decreased the PM localization and increased the endomembrane association of H-Ras,
N-Ras, and Lck, which are targeted to the PM via the exocytic pathway, regardless of their functional state. In contrast, the subcellular distribution of K-Ras and Fyn, of which transport is independent of the vesicular transport pathway, was unaffected by DHA. Moreover, DHA selectively inhibited lipidated cytosolic protein targeting since the PM delivery of transmembrane protein cargo was unaffected, indicating that DHA does not alter the bulk flow of secretory vesicular traffic. Overall, the present study presents compelling evidence that select dietary constituents with membrane lipid-modifying properties can differentially modulate subcellular localization of important lipidated signaling proteins depending on their intracellular trafficking route to the PM.
46
Schmidt, Madelyn R. "Virus-Lymphocyte Interactions: Virus Expression Is Differentially Modulated by B Cell Activation Signals: A Dissertation." eScholarship@UMMS, 1991. https://escholarship.umassmed.edu/gsbs_diss/51.
Full textAbstract:
It is shown here that the ability of B lymphocytes to act as supportive host cells for virus infections requires they be activated from the resting Gostage of the cell cycle. I have used a series of activation regimens, which allow B cells to progress to different stages in their activation/differentiation pathway toward antibody secretion, in order to evaluate the extent of activation required to support vesicular stomatitis or Newcastle disease virus infections.
At least three distinct phases during B cell activation which affected VSV infection were defined. Freshly isolated resting murine splenic B cells in the Go phase of the cell cycle do not support VSV, assessed by protein synthesis, infectious center formation, and PFU production. Small B cells cultured for 48 hours without stimulation still do not support VSV. B cells stimulated with the lymphokines found in Con A activated supernatants from splenic T cells or cloned T cell lines transited into the G1 phase of the cell cycle but remain refractory to VSV. These VSV non-supportive B cell populations do take up virus particles and transcribe viral mRNAs which can be translated in vitro, suggesting a translational block to VSV. B cells stimulated into the S phase of the cell cycle with anti-immunoglobulin synthesize VSV proteins and increased numbers of infectious centers, but only low level PFU synthesis (center) is observed. Co-stimulation with anti-Ig and lymphokines, which supports differentiation to antibody secretion, enhanced PFU synthesis without further increasing the number of infected B cells. LPS, which activates B cells directly to antibody secretion by a pathway different from anti-Ig, induced infectious centers, and PFUs at levels comparable to those seen when stably transformed permissive cell lines are infected. Co-stimulation of LPS activated B cells with the same lymphokine populations that enhance PFU production when anti-Ig is used as a stimulator suppresses PFU production completely, suggesting that anti-Ig and LPS activated B cells are differentially responsive to lymphokines.
NDV infection of murine B cells differed markedly from VSV infection, as all B cell populations examined gave a similar response pattern. NDV viral proteins were synthesized by B cells in each of the activation states previously described, even freshly isolated B cells. Infectious center formation increased up to 5-fold over the levels observed with unstimulated B cells after anti-Ig or LPS activation. However, PFU synthesis was low (center) for all B cell populations.
These results suggest that these two similar viruses may be dependent on different host cell factors and that these factors are induced for VSV but not NDV by the B cell activators employed here or that the process of infection of B cell by these two viruses induces different cellular responses.
47
Martin, James D. (James Dudley). "Rankin-Cohen Brackets for Hermitian Jacobi Forms and Hermitian Modular Forms." Thesis, University of North Texas, 2016. https://digital.library.unt.edu/ark:/67531/metadc955117/.
Full textAbstract:
In this thesis, we define differential operators for Hermitian Jacobi forms and Hermitian modular forms over the Gaussian number field Q(i). In particular, we construct Rankin-Cohen brackets for such spaces of Hermitian Jacobi forms and Hermitian modular forms. As an application, we extend Rankin's method to the case of Hermitian Jacobi forms. Finally we compute Fourier series coefficients of Hermitian modular forms, which allow us to give an example of the first Rankin-Cohen bracket of two Hermitian modular forms. In the appendix, we provide tables of Fourier series coefficients of Hermitian modular forms and also the computer source code that we used to compute such Fourier coefficients.
48
Al-Khafaji, Ahmed. "Investigation of molecular modulation of taxane response in respiratory tract cancers by differential expression of mitotic spindle associated genes." Thesis, University of Liverpool, 2015. http://livrepository.liverpool.ac.uk/2037905/.
Full textAbstract:
Respiratory (Lung and head and neck) cancers contribute highly to the burden of cancer-related deaths. Taxanes are microtubule-targeting agents used to treat a variety of human cancers. Paclitaxel and Docetaxel represent the most prominent members of the taxane family, demonstrating significant activity mainly as part of complex chemotherapeutic regimens. Mitotic spindle formation and spindle checkpoint are critical for the maintenance of cell division and chromosome segregation. Many of mitotic spindle associated members, including AURKA, AURKB, AURKC, CKAP5, DLGAP5, KIF11, TPX2, TUBB, TUBB3, and TTK are implicated in several malignancies including lung cancer due to their frequent deregulation and may be associated with response to taxanes based therapy in NSCLC. The aims of this project were to 1) Explore the association between the expression profiles of ten genes listed above and clinicopathological characteristics in human non-small cell lung carcinoma and 2) Investigate the potential of some of these genes to predict response to taxane involving regimens in lung and head and neck cancerous cells. qPCR-based RNA gene expression profiles of 132 non-small cell lung carcinomas (NSCLC) and 44 adjacent normal tissues were generated and Cox proportional hazard regression was used to examine associations. Associations between mitotic spindle gene expression and resistance to both taxanes were established in 23 cancer cell lines of respiratory tract origin. AURKA mRNA expression (Hazard Ratio (HR)= 1.81; 95%CI 1.16-2.84, P= 0.009) was the only molecular independent predictor of poor prognosis in patients with NSCLC. Poor prognosis of those patients with high AURKA expression suggests they may benefit from combined therapy with AURKA inhibitors. Furthermore, in LUDLU1, SKLU1 and SK-MES1 cell lines, shRNA driven AURKA down-regulation sensitized cells to docetaxel. Inhibition of Aurora A kinase activity using the selective inhibitor alisertib augmented docetaxel efficiency in the above mentioned cell lines. AURKB overexpression in NSCLC cell lines strongly correlated with resistance to both docetaxel (p=0.0016) and paclitaxel (p=0.0096). Conversely, AURKB knock down derivatives of two cell lines consistently showed a dose-dependent association between AURKB mRNA expression and resistance to paclitaxel. Inhibition of Aurora B activity by barasertib also demonstrated a strong dose-dependent efficiency in triggering paclitaxel resistance in all the cell lines tested. This study clearly demonstrated that AURKA mRNA over-expression could prognosticate the clinical outcome in NSCLC patients suggesting that patients bearing tumours with high AURKA expression may benefit from combined use of AURKA inhibitors. The present study has also clearly uncovered a role for AURKB in the response of NSCLC cells to paclitaxel and provided unique evidence for a dose-dependent association. Given the large extent of AURKB deregulation in NSCLC, these findings suggest that assessing the levels of AURKB protein in surgical samples could become a determinant in the clinical decision tree for managing patients and have potential for development as a predictive biomarker.
49
Culha, Onur. "Noncoherent Differential Demodulation Of Cpm Signals With Joint Frequency Offset And Symbol Timing Estimation." Master's thesis, METU, 2011. http://etd.lib.metu.edu.tr/upload/12613729/index.pdf.
Full textAbstract:
In this thesis, noncoherent differential demodulation of CPM signals with joint
carrier frequency offset and symbol timing estimation is investigated. CPM is very
attractive for wireless communications owing to major properties: good spectral
efficiency and a constant envelope property. In order to demodulate the received
CPM signal differentially, the symbol timing and the carrier frequency offset have
to be estimated accurately. There are numerous methods developed for the
purpose. However, we have not encountered studies (which are based on autocorrelation
estimation and hence suitable for blind synchronization) that give
expectable performance for both M-ary and partial response signaling. Thus, in
this thesis we analyze a feedforward blind estimation scheme, which recovers the
symbol timing and the frequency offset of M-ary CPM signals and partial response
CPM signals. In addition, we surveyed low complexity symbol detection methods
for CPM signals. Reduced state Viterbi differential detector incorporated to the
joint frequency offset and symbol timing estimator is also examined. The
performance of the examined demodulator scheme is assessed for the AWGN
channel by computer simulations.
50
Zhao, Jing. "Protein Kinases can differentially regulate transactivation activities of hLRH-1 through the modulation of cofactors interactions." Kent State University / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=kent1271686070.
Full text