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Li, Weiwei. "Optimal control for biological movement systems." Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2006. http://wwwlib.umi.com/cr/ucsd/fullcit?p3205051.
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Thesis (Ph. D.)--University of California, San Diego, 2006.<br>Title from first page of PDF file (viewed April 4, 2006). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references (p. 131-146).
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Brenner, Sibylle. "Mechanistic Control of Biological Redox Systems." Thesis, University of Manchester, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.518447.
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Qian, Yili. "Systems and control theoretic approaches to engineer robust biological systems." Thesis, Massachusetts Institute of Technology, 2020. https://hdl.handle.net/1721.1/128991.
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Thesis: Ph. D., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2020<br>Cataloged from student-submitted PDF of thesis.<br>Includes bibliographical references (pages 189-203).<br>Synthetic biology is an emerging field of research aimed to engineer biological systems by inserting programmed DNA molecules into living cells. These DNAs encode the production and subsequent interactions of biomolecules that allow the cells to have novel sensing, computing, and actuation capabilities. However, most success stories to date rely heavily on trial and error. This is mainly because genetic systems are context-dependent: the expression level of a synthetic gene often depends not only on its own regulatory inputs, but also on the expression of other supposedly unconnected genes. This lack of modularity leads to unexpected behaviors when multiple genetic subsystems are composed together, making it difficult to engineer complex systems that function predictably and robustly in practice. This thesis characterizes resource competition as a form of context dependence, and presents control theoretic approaches to engineer robust, context-independent gene networks. We first present a systems framework to model resource competition, which results in a hidden layer of unintended interactions among genetic subsystems. These unintended interactions lead to failure of the composed network in experiment. We then introduce a set of biomolecular controllers - designed to solve an output regulation problem in vivo - that can decouple a genetic subsystem's output from its context. We describe challenges applying classical control theory to engineer such controllers due to the physical constraints in living cells, and then present novel theory-guided engineering solutions. Finally, we point to additional design considerations when regulating multiple subsystems using multiple controllers in a single cell. These works have the potential to enhance the robustness of future synthetic biological systems and to fully unleash their power to address pressing societal needs in environment, energy, and health.<br>by Yili Qian.<br>Ph. D.<br>Ph.D. Massachusetts Institute of Technology, Department of Mechanical Engineering
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Panchea, Adina. "Inverse optimal control for redundant systems of biological motion." Thesis, Orléans, 2015. http://www.theses.fr/2015ORLE2050/document.
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Cette thèse aborde les problèmes inverses de contrôle optimal (IOCP) pour trouver les fonctions de coûts pour lesquelles les mouvements humains sont optimaux. En supposant que les observations de mouvements humains sont parfaites, alors que le processus de commande du moteur humain est imparfait, nous proposons un algorithme de commande approximative optimale. En appliquant notre algorithme pour les observations de mouvement humaines collectées: mouvement du bras humain au cours d'une tâche de vissage industrielle, une tâche de suivi visuel d’une cible et une tâche d'initialisation de la marche, nous avons effectué une analyse en boucle ouverte. Pour les trois cas, notre algorithme a trouvé les fonctions de coût qui correspondent mieux ces données, tout en satisfaisant approximativement les Karush-Kuhn-Tucker (KKT) conditions d'optimalité. Notre algorithme offre un beau temps de calcul pour tous les cas, fournir une opportunité pour son utilisation dans les applications en ligne. Pour la tâche de suivi visuel d’une cible, nous avons étudié une modélisation en boucle fermée avec deux boucles de rétroaction PD. Avec des données artificielles, nous avons obtenu des résultats cohérents en termes de tendances des gains et les critères trouvent par notre algorithme pour la tâche de suivi visuel d’une cible. Dans la seconde partie de notre travail, nous avons proposé une nouvelle approche pour résoudre l’IOCP, dans un cadre d'erreur bornée. Dans cette approche, nous supposons que le processus de contrôle moteur humain est parfait tandis que les observations ont des erreurs et des incertitudes d'agir sur eux, étant imparfaite. Les erreurs sont délimitées avec des limites connues, sinon inconnu. Notre approche trouve l'ensemble convexe de de fonction de coût réalisables avec la certitude qu'il comprend la vraie solution. Nous numériquement garanties en utilisant des outils d'analyse d'intervalle<br>This thesis addresses inverse optimal control problems (IOCP) to find the cost functions for which the human motions are optimal. Assuming that the human motion observations are perfect, while the human motor control process is imperfect, we propose an approximately optimal control algorithm. By applying our algorithm to the human motion observations collected for: the human arm trajectories during an industrial screwing task, a postural coordination in a visual tracking task and a walking gait initialization task, we performed an open loop analysis. For the three cases, our algorithm returned the cost functions which better fit these data, while approximately satisfying the Karush-Kuhn-Tucker (KKT) optimality conditions. Our algorithm offers a nice computational time for all cases, providing an opportunity for its use in online applications. For the visual tracking task, we investigated a closed loop modeling with two PD feedback loops. With artificial data, we obtained consistent results in terms of feedback gains’ trends and criteria exhibited by our algorithm for the visual tracking task. In the second part of our work, we proposed a new approach to solving the IOCP, in a bounded error framework. In this approach, we assume that the human motor control process is perfect while the observations have errors and uncertainties acting on them, being imperfect. The errors are bounded with known bounds, otherwise unknown. Our approach finds the convex hull of the set of feasible cost function with a certainty that it includes the true solution. We numerically guaranteed this using interval analysis tools
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Chandra, Manik. "Analytical study of a control algorithm based on emotional processing." Thesis, Texas A&M University, 2005. http://hdl.handle.net/1969.1/4914.
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This work presents a control algorithm developed from the mammalian emotional processing network. Emotions are processed by the limbic system in the mammalian brain. This system consists of several components that carry out different tasks. The system level understanding of the limbic system has been previously captured in a discrete event computational model. This computational model was modified suitably to be used as a feedback mechanism to regulate the output of a continuous-time first order plant. An extension to a class of nonlinear plants is also discussed. The combined system of the modified model and the linear plant are represented as a set of bilinear differential equations valid in a half space of the 3-dimensional real space. The bounding plane of this half space is the zero level of the square of the plant output. This system of equations possesses a continuous set of equilibrium points which lies on the bounding plane of the half space. The occurrence of a connected equilibrium set is uncommon in control engineering, and to prove stability for such cases one needs an extended Lyapunov-like theorem, namely LaSalle's Invariance Principle. In the process of using this Principle, it is shown that this set of equations possesses a first integral as well. A first integral is identified using the compatibility method, and this first integral is utilized to prove asymptotic stability for a region of the connect equilibrium set.
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Govender, Veloshinie. "Evaluation of biological control systems for control of mango post-harvest diseases." Pretoria : [s.n.], 2004. http://upetd.up.ac.za/thesis/available/etd-02102006-160747.
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Tomazou, Marios. "Towards light based dynamic control of synthetic biological systems." Thesis, Imperial College London, 2014. http://hdl.handle.net/10044/1/44243.
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For the field of synthetic biology, the adaptation of principles, from the well established traditional engineering disciplines, like mechanical and electrical engineering, in order to realise complex synthetic biological circuits, is an intriguing prospect. These principles can enable a forward engineering, rational design and implementation approach, where a system's properties can be predicted or designed in silico followed by the manufacturing of the in vivo system, that can be tested, used or redesigned in the most efficient possible way. Achieving control over these circuits, is one of the important topics of the field, for these applications to become robust and render useful functions applicable to energy, medicine, pharmaceuticals and agriculture industries. In this work, I attempt to explore light, as a promising control 'dial' for synthetic circuitry. Light is fast, economic compared to chemicals, it can be interfaced with electronics, it is reversible in its effect and can be applied at a fine spatio-temporal resolution. These characteristics, are absent from the classically used chemical inducers, meaning that light, can open new possibilities for the user to control synthetic systems, or even facilitate the cell to cell communication, within population based networks. This work, is a contribution towards harnessing the advantages of light, for achieving control over synthetic circuits. More specifically, I start with the detailed theoretical and experimental study of the Cph8 two component system, a synthetic chimeric receptor which is responsive to red light. This is done, in order to develop a sufficient theoretical understanding of it, through detailed mechanistic modelling, in order to connect the specific system with the toggle switch and the dual feedback oscillator, in an optimal way and achieve control of these devices through light. The developed model, was able to highlight the main aspects and mechanisms inherent to its structure, describe most of the observations from the experimental system, to also make quantitative predictions. The second part of this work, was the development of novel promoters, that can be regulated by a commonly used transcription factor, such as LacI, but also, light responsive regulators like OmpR and CcaR. This yielded a direct way to integrate light and chemical inputs, into a single output, while the dual regulation, allowed to connect and modulate the toggle switch without the need of additional transcription factors. The latter, a light tuneable toggle switch, showed indications that it can function as a memory controller that can be reset by light. Finally, I show the design and modelling of a light tuneable dual feedback oscillator, where light of one wavelength can be used to tune the amplitude, while another wavelength can tune the period. The developed models and synthetic circuits are expected to contribute towards implementing finely tuned and controlled synthetic circuits through light.
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Segall-Shapiro, Thomas Hale. "Regulatory systems for the robust control of engineered genetic programs." Thesis, Massachusetts Institute of Technology, 2017. http://hdl.handle.net/1721.1/113965.
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Thesis: Ph. D., Massachusetts Institute of Technology, Department of Biological Engineering, 2017.<br>Cataloged from PDF version of thesis.<br>Includes bibliographical references (pages 143-159).<br>The ability to engineer complex genetic programs could have a huge impact on many industries, yielding organisms that can respond to their environment and perform functions relevant to manufacturing, agriculture, and medicine. However, such engineering efforts have proven difficult, in part because these programs often require precise levels of gene expression for proper function. It is especially tough to build programs that have robust activity, as any changes to the host cells can perturb the context of the genetic system and disrupt carefully tuned expression levels. Additionally, genetic programs often place high demands on host resources, which can adversely affect cell growth and further upset the intended function. In this thesis, we describe two regulatory systems in Escherichia coli that could serve to separate synthetic genetic programs from their host context, potentially leading to more robust activity. First, we build a 'resource allocator' by fragmenting T7 RNA polymerase variants into a conserved fragment and a set of variable fragments. The resource allocator limits the total number of polymerases that can be active in a genetic program, with the aim of protecting the host from being overburdened. This transcriptional budget can be allocated to different elements of the genetic program as necessary and further regulated using additional protein fragments. Second, we demonstrate a set of stabilized promoters that can maintain a level of gene expression independent of their genetic context. These promoters utilize a noncooperative incoherent feedforward loop to buffer differences in gene expression caused by changes in copy number. We demonstrate that stabilized promoters can be moved between plasmids and different locations on the genome with little change in expression. Further, they minimize the effects of other perturbations that can affect copy number, such as genome mutations and media composition.<br>by Thomas Hale Segall-Shapiro.<br>Ph. D.
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Molenaar, Robert. "Design and implementation of biosystem control and tools for biosystem simulation." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape11/PQDD_0017/NQ44519.pdf.
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Stoltz, Scott. "The effects of biofeedback plus progressive relaxation on the emotional well-being of college students." Online version, 2000. http://www.uwstout.edu/lib/thesis/2000/2000stoltzs.pdf.
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Kim, Myeongseop. "MICRO-GAS EXCHANGER FOR OXYGEN TENSION CONTROL IN BIOLOGICAL MICROFLUIDIC SYSTEMS." Case Western Reserve University School of Graduate Studies / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=case1462871978.
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AMARAL, Thiago Magalhães. "Optimal control in biological systems as a support for clinical decisions." Universidade Federal de Pernambuco, 2009. https://repositorio.ufpe.br/handle/123456789/6002.
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Previous issue date: 2009<br>Coordenação de Aperfeiçoamento de Pessoal de Nível Superior<br>O controle ótimo no mundo biológico tem uma vasta aplicação em incontáveis sistemas
os quais influenciam enormemente nossas vidas. Objetiva-se a aplicação desta ferramenta
em dois sistemas. O primeiro diz respeito ao controle ótimo de dosagem de drogas no
tratamento de pacientes infectados pelo vírus HIV . O modelo de Campello de Souza
(1999) é usado para estimar a dosagem de drogas onde a função objetivo é minimizada.
Esta função representa um balanço entre os benefícios do tratamento e os efeitos colaterais.
A técnica de controle ótimo usada é o Princípio do Máximo de Pontryagin, a qual é simulada
através do PROPT-TOMLAB - Matlab Optimal Control System Software em uma
versão de demonstração. As simulações objetivam a análise de três diferentes pacientes
em dois diferentes cenários. Estes cenários têm como objetivo forçar as variáveis de estado
a atingirem valores "normais" a fim de estabilizar a carga viral próximo a uma taxa que
seja insignificante e elevar o nível de CD4 do paciente. São simulados tratamentos cedos
e tardios. As simulações computacionais compararam diferentes cenários para investigar
os parâmetros de incerteza da dinâmica entre o vírus HIV e os linfócitos CD4 e CD8.
Os resultados mostram que o controle ótimo permite uma melhor administração entre os
efeitos positivos da terapia e os efeitos colaterais, ao invés de se usar dosagens constantes
de drogas como na atual prática médica. O segundo sistema descreve a aplicação do
controle ótimo, também através do Princípio Máximo de Pontryagin, para controlar o
nível de glicose em indivíduos diabéticos usando o modelo matemático desenvolvido por
Bergman (1971, 1981). Correlacionam-se dados reais da literatura com o modelo teórico
para analisar a robustez do modelo. É também estudada a minimização do funcional objetivo
para diminuir os efeitos colaterais e consequentemente melhorar o estado de saúde
do paciente. Os resultados mostram os benefícios de se utilizar o controle ótimo para
regular a taxa de glicose em pacientes diabéticos
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Koh, Carolyn Ann. "The control of aluminium complexation in catalytic, cement colloidal and biological systems." Thesis, Brunel University, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.290955.
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August, Elias. "Stability and dissipativity theory for nonnegative and compartmental dynamical systems." Thesis, Georgia Institute of Technology, 2001. http://hdl.handle.net/1853/13068.
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Ton, That Long. "Nonlinear control studies for circadian models in system biology." Thesis, University of Manchester, 2011. https://www.research.manchester.ac.uk/portal/en/theses/nonlinear-control-studies-for-circadian-models-in-system-biology(f616f360-99e4-4314-ba51-be7a49e9ff0e).html.
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Circadian rhythms exist in almost all of living species, and they occupy an important role in daily biological activities of these species. This thesis deals with reduction of measurements in circadian models, and recovery of circadian phases. Two mathematical models of circadian rhythms are considered, with a 3rd order model for Neurospora, and a 7th order model for Mammals. The reduction of measurements of circadian models is shown by the proposals of observer designs to the two mathematical models of circadian rhythms. Both mathematical models contain strong nonlinearities, which make the observer design challenging. Two observer designs, reduced-order and one-sided Lipschitz, are applied to the circadian models to tackle the nonlinearities. Reduced-order observer design is based on a state transformation to make certain nonlinearities have no impact on the observer errors, and the design of one-sided Lipschitz observer is based on systems with one-sided Lipschitz nonlinearities. Both observer designs are based on the existing methods in literature. The existing method of reduced-order observer has been applied to a class of multi-output nonlinear systems. A new reduced-order observer design which extends the existing one in literature is presented in this thesis. In this new reduced-order observer method, the observer error dynamics can be designed by choosing the observer gain, unlike the existing one, of which the observer error dynamics depend on the invariant zeros under certain input-output map. The recovery of circadian phases is carried out to provide a solution to phase shifts occurred in circadian disorders. The restoration of circadian phases is performed by the synchronizations of trajectories of a controlled model with trajectories of a reference model. The reference model and the controlled model have phase differences, and both these models are based on a given 3rd order model of Neurospora circadian rhythms. The phase differences are reflected by different initial conditions, and by parameter uncertainty. The synchronizations of the two models are performed by using back-stepping method for the case of different initial conditions, and by using adaptive back-stepping method for the remaining case. Several simulation studies of the proposed observer designs and the proposed schemes of synchronizations are carried out with the results shown in this thesis.
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Boguena, Toupta. "Epidemiology of Ustilago bullata Berk. on Bromus tectorum L. and implications for biological control /." Diss., CLICK HERE for online access, 2003. http://contentdm.lib.byu.edu/ETD/image/etd261.pdf.
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Sartini. "The effect of inoculum density, virulency, and carrier systems of phoma sp. on biological control of giant foxtail (setaria faberi hermm.)." Virtual Press, 1995. http://liblink.bsu.edu/uhtbin/catkey/955092.
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The effect of spore titer, virulency, and carrier systems on biological control of giant foxtail (Setaria faberi hermm.) with a species of Phoma isolated from this weed wereinvestigated. The lowest concentration of Phoma conidia which significantly affected (lowered) growth of giant foxtail was 1x106 conidia/ml. In conducting Koch's postulates, all but one (FF2) of the Phoma, isolates tested infected giant foxtail. Isolates FF1 and FF9 were the most virulent against giant foxtail. No correlation was apparent between virulency and fungus germination rate. No visible difference occurred with in vitro germination rates of spores incubated upon pea vsr water agar media; nutrient rich vs. nutrient poor media, respectively. These results suggest that Phoma spores already contain sufficient nutrients required for infection of foxtail. A definitive answer as to the effect of carrier system (e.g. surfactant, sticker, spreader, etc.) on efficacy of Phoma to infect foxtail could not be determined from results obtained, based upon statistical analysis of variance (ANOVA) for the single experiment performed. Several of the surfactant treatments (e.g. Silwet 77 and 408) did produce significant biomass losses against foxtail due to the phytotoxicity of the carrier system alone, and not reflective of fungal (Phoma) infection. Inoculation of foxtail plants with a conidial suspension amended with carriers of either Tween 20 (0.05%-0.1%) or methylcellulose (0.1%) should optimize chances for sufficient infection resulting in biological control of this weed.<br>Department of Biology
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Chu, Yan-shuen Jessica. "Secretin a putative factor in regulating body water homeostasis /." Click to view the E-thesis via HKUTO, 2008. http://sunzi.lib.hku.hk/HKUTO/record/B39558654.
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Pearson, Karen Aileen. "Characterisation of Fusarium isolates infecting roots of ragwort (Jacobaea vulgaris syn. Senecio jacobaea) and an assessment of their potential as a biological control agents." Thesis, University of Aberdeen, 2011. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=166174.
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Ragwort (Jacobaea vulgaris syn. Senecio jacobaea), a common weed of pasture and poorly managed land worldwide, is toxic to livestock and horses. There is no fully satisfactory control option available. The aim of the work described in this thesis was to assess the potential of root infecting pathogens to cause disease in ragwort, and to examine the possibility of using them as biological control agents against this weed. Thirty-six root infecting isolates were obtained from ragwort roots, collected from a nationwide postal survey where Pony Club adult leaders were asked to provide samples. Twenty-one of these were identified as Fusarium spp. by morphological identification and tested for the ability to cause disease on aseptically raised ragwort seedlings. Twelve isolates demonstrated virulence towards ragwort when measured by disease score over a 14 day period. These isolates were identified by molecular means using the internal transcribed spacer and translation elongation factor genes, as either Fusarium avenaceum or F. acuminatum while isolates of F. solani, F. redolens, F. cerealis or F. culmorum did not exhibit virulence except one isolate of F. culmorum which was weakly virulent. To investigate the biological control potential of virulent isolates, a representative of F. avenaceum and F. acuminatum plus the one weakly virulent F. culmorum isolate, were tested against plants of agricultural importance in grasslands. Six grasses (crested dogs tail, Cynosurus cristatus; Timothy, Phleum pratense; red fescue Festuca rubra; Italian ryegrass, Lolium multiflorum; and two varieties of perennial ryegrass, L. perenne) were unaffected by inoculation with any of the isolates. There was no significant difference between the symptoms caused by F. avenaceum and F. acuminatum on ragwort, red clover (Trifolium pratense) and white clover (T. repens). F. culmorum was more virulent towards white clover than either red clover or ragwort. This suggests that although high concentrations of pure PA may inhibit fungal growth, the range of other nutrients in the plants can counteract this negative effect.
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Chu, Yan-shuen Jessica, and 朱恩璿. "Secretin: a putative factor in regulating body water homeostasis." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2008. http://hub.hku.hk/bib/B39558654.
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Tingey, David. "Estimation and control of some classes of dynamical systems with application to biological wastewater treatment." Thesis, Northumbria University, 2007. http://nrl.northumbria.ac.uk/1222/.
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It is well-known that there are no general approaches for observer and controller design for nonlinear systems. Instead, focus is placed upon design for classes of systems. On the other hand, a wide variety of dynamical systems belong to the class of state-affine systems. Amongst these are biological wastewater treatment processes, which are essential in order to prevent pollution in the environment and prevent disease in the consumption of recycled water. An interesting aspect found in biological wastewater treatment systems, and many typical industrial processes, are time-delays. In almost all systems there are time-delays and nonlinearities and it is not surprising that time-delay and nonlinear systems have received a great deal of attention in mathematics and control engineering. This project introduces new methodologies for the design of controllers and observers for a class of state-affine systems and a class of linear time-delay systems. Firstly, new observable and controllable canonical forms are introduced. These are then used to establish new controller and observer design methodologies for a class of state¬affine systems. In particular, an adaptive observer design is established. The methodologies are simple since they are based upon linear techniques. Secondly, a full-state controller and a separation principle are established for a class of single-input single-output linear time-delay systems. The designs are based on a new stability criterion and are derived from first principles. Finally, the new observer design methodology for the class of state-affine systems is used to produce observers for the estimation of biomass concentration in a biological wastewater treatment bioreactor. The observers are applied in theory and in simulation, where a full and a partial knowledge of the kinetic rate of reaction of biomass are considered. In addition, the performances are shown both in the absence and in the presence of measurement noise for a variety of influent flow characteristics.
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Simoni, Mario F. "Synthesis and analysis of a physical model of biological rhythmic motor control with sensorimotor feedback." Diss., Georgia Institute of Technology, 2002. http://hdl.handle.net/1853/13284.
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Folman, Larissa Berendina. "Biological control of Pythium aphanidermatum in soilless systems : selection of biocontrol agents and modes of action /." Leiden : Universiteit Leiden, 2003. http://catalogue.bnf.fr/ark:/12148/cb39932825t.
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Hyink, Otto, and n/a. "Genes that define the Nucleopolyhedrovirus of Epiphyas postvittana." University of Otago. Department of Microbiology & Immunology, 2005. http://adt.otago.ac.nz./public/adt-NZDU20060808.143556.
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The nucleopolyhedrovirus of Epiphyas postvittana (EppoMNPV) is being studied as a potential biological control agent for leafroller insects in New Zealand. The aims of this project were for the identification of putative genes that are unique to, variant in or missing from, the EppoMNPV genome and the subsequent analysis of at least one of these genes. The purpose of this was to identify and characterise genes potentially involved in the specific host range and virulence of EppoMNPV. This was achieved in two steps. Three genome regions lacking linearity between EppoMNPV and the closely related OpMNPV were previously identified and the targeted sequencing of these three regions was the first aim of this project. The collation of the entire genome sequence of EppoMNPV and comparison to the genome sequences of 22 other baculoviruses completed the identification of genes that are unique to, variant in or missing from EppoMNPV. The EppoMNPV genome was found to be 118,584 bp in size encoding 136 putative proteins. A total of 29 genes were found to be common to all baculoviruses, while the lepidopteran baculoviruses share a total of 62 genes. The genome of EppoMNPV encodes four putative unique genes, the sequence of which offers no clues as to possible function. EppoMNPV lacks a homologue of the superoxide dismutase gene common to all other lepidopteran baculoviruses The EppoMNPV IE2 homologue was identified as a 311 amino acid protein with a truncation in the N-terminal region. We hypothesised that this truncation would lead to a loss of function, which could contribute to the virulence and/or host range of EppoMNPV For this reason, the characterisation of the EppoMNPV IE2 was taken up as the second part of this project. A comparative study between the AcMNPV and EppoMNPV IE2 proteins identified no differences in function between these two proteins in Sf21 cells. The EppoMNPV IE2 was capable of trans-activating three constitutive promoters and localised to discrete nuclear bodies. Cell cycle arrest was not achieved by either IE2 protein in our cell culture system. The role of four sequence motifs common to all IE2 proteins was studied with the aid of mutational analysis. Mutation of arginine and acidic rich sequences of EppoMNPV IE2 showed only a slight decrease in trans-activation activity while mutation of the RING-finger and coiled-coil motifs reduced trans-activation to less than half that of wild type IE2. Mutation of the coiled-coil motif resulted in reduced amounts of protein localising to discrete nuclear regions. A series of deletion mutants from the N- and C-termini of EppoMNPV IE2 identified that the C-terminal 111 amino acids of EppoMNPV IE2 was sufficient for nuclear targeting. Deletion of the C-terminal 19 amino acids resulted in an IE2 mutant completely defective in both localisation and transactivation. This demonstrates that localisation to discrete nuclear regions is essential for EppoMNPV IE2 to act as a transactivator.
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Jarkowski, Nancy Lee 1955. "THE EFFECTS OF THERMAL BIOFEEDBACK THERAPY ON PATIENTS IN A CARDIAC REHABILITATION PROGRAM." Thesis, The University of Arizona, 1987. http://hdl.handle.net/10150/276379.
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Hong, Min. "Implicit constraint enforcement to control the physically-based biomedical simulation /." Connect to full text via ProQuest. IP filtered, 2005.
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Williams, Carrie. "Influence of Sensory Feedback on Rhythmic Movement: A Computational Study of Resonance Tuning in Biological Systems." Diss., Available online, Georgia Institute of Technology, 2006, 2006. http://etd.gatech.edu/theses/available/etd-11172006-180642/.
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Thesis (Ph. D.)--Biomedical Engineering, Georgia Institute of Technology, 2007.<br>DeWeerth, Stephen, Committee Chair ; Lee, Robert, Committee Member ; Ting, Lena, Committee Member ; Katz, Paul, Committee Member ; Butera, Robert, Committee Member.
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Moore, Lisa Marie. "Molecular and Field Analyses of Bathyplectes spp. (Hymenoptera: Ichneumonidae) in Alfalfa Systems in Virginia." Diss., Virginia Tech, 2014. http://hdl.handle.net/10919/47793.
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Bathyplectes anurus (Thomson) and B. curculionis (Thomson) (Hymenoptera: Ichneumonidae) are specialist parasitoids introduced to the United States for classical biological control of alfalfa weevil, Hypera postica (Coleoptera: Curculionidae). Adults of both species are morphologically similar, generally described as wasps ≈3-4 mm long with black, robust bodies. The Bathyplectes spp. occupy sympatric ranges throughout much of the United States and often coexist within alfalfa fields. In Virginia, B. anurus is the primary biological control agent, accounting for more than 90% of alfalfa weevil parasitization. A previous study, however, found that the levels of control by B. anurus varied among the three alfalfa-growing regions of Virginia, and noted that little is known about the mechanisms or factors responsible for the differential levels of parasitization. Of the factors that may affect host parasitization, three were addressed in this study: population density and spatial distribution of host and parasitoid, the effectiveness of parasitoids in response to host density as measured by the population functional response, and genetic variation among and between populations of parasitoids. GPS-referenced quadrat sampling was conducted in alfalfa fields in the Piedmont and southwestern region to assess alfalfa weevil population levels and spatial distribution, and the level and distribution of parasitization by B. anurus and B. curculionis. Results showed that there was no significant difference in alfalfa weevil densities among alfalfa fields in the Piedmont and southwestern region, and also no significant difference between regions in the level of parasitization. Mean alfalfa weevil density per 0.2-m2 quadrat per sampling date was 11.0 in the Piedmont and 8.0 in the southwestern region; mean percent parasitization per 0.2-m2 quadrat per sampling date was 9.1% in the Piedmont and 9.9% in the southwestern region. The spatial distributions of alfalfa weevil larvae and parasitization were found to be aggregated in all alfalfa fields sampled. The population functional response of B. anurus attack on alfalfa weevil was determined qualitatively to be Type II in all alfalfa fields sampled, except the field located at Blacksburg in the southwestern region. The Type II functional response suggests that, in general, the parasitoid has an inverse density dependent attack response to the density of alfalfa weevil larvae in the two regions of Virginia.
Molecular analyses were conducted to 1) derive genetic sequences for B. anurus and B. curculionis, which could be used to identify and differentiate the two species, and 2) test for genetic variation within and between regional populations of Bathyplectes. Sequences for each species were obtained for the D2–D3 region of the 28S ribosomal DNA (28S rDNA) gene; sequence identity between B. anurus and B. curculionis was 96.6%. The 28S rDNA sequences were also obtained for another Bathyplectes species, possibly B. stenostigma, and for four taxa of Hymenoptera that hyperparasitize B. anurus and B. curculionis cocoons. Sequences were obtained for B. anurus and B. curculionis for a portion of the mitochondrial gene cytochrome oxidase subunit 1 (COI); sequence identity between B. anurus and B. curculionis was 89.7%. Genetic variation in the COI gene was observed for both species. One variation of the COI sequence expressed by 25% of B. anurus specimens (Haplotype 2) might indicate regional genetic variation correlated to temperature, in particular the average number of days per year that a region experiences temperatures above 32°C. Two major COI sequence haplotypes found in B. curculionis specimens might be indicative of incipient speciation.<br>Ph. D.
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Walker, Kenneth N. (Kenneth Neal). "Differential Effects of Biofeedback Input on Lowering Frontalis Electromyographic Levels in Right and Left Handers." Thesis, University of North Texas, 1990. https://digital.library.unt.edu/ark:/67531/metadc331405/.
Full textAbstract:
This investigation was an attempt to replicate and expand previous research which suggested that laterality of electromyographic biofeedback input had a significant effect in lowering frontalis muscle activity. In 1984 Ginn and Harrell conducted a study in which they reported that subjects receiving left ear only audio biofeedback had significantly greater reductions in frontalis muscle activity than those receiving right ear only or both ear feedback. This study was limited to one biofeedback session and subjects were selected based on demonstration of right hand/ear dominance. The purpose of the present study was to determine whether the left ear effect reported by Ginn and Harrell could be replicated. Furthermore, the current investigation sought to extend the previous finding to left handed subjects and explore the stability of the effect, if found, by adding a second biofeedback session.
Subjects were 96 students recruited from undergraduate psychology classes. They were screened for handedness by the Edinburgh Handedness Inventory which resulted in identification of 48 right handers and 48 left handers. Subjects were randomly assigned to one of four groups consisting of left ear feedback, right ear feedback, both ears feedback, and controls. This resulted in eight conditions.
Analysis of variance of microvolt changes from baseline found no statistically significant differences between groups. An examination of the rank order of the data reveal a left ear group performance in the same direction as those reported by Ginn and Harrell (1984).
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Jones, Kymry Thereasa. "The role of beta-arrestin in regulating the muscarinic acetylcholine type II receptor." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2007. http://hdl.handle.net/1853/24815.
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Thesis (Ph.D.)--Biology, Georgia Institute of Technology, 2008.<br>Committee Chair: Dr. Nael A. McCarty; Committee Co-Chair: Dr. Darrell Jackson; Committee Member: Dr. Alfred H. Merrill; Committee Member: Dr. Barbara D. Boyan; Committee Member: Dr. Harish Radhakrishna; Committee Member: Dr. Marion B. Sewer
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Murphy, Michael A. "The effects of rational stage directed therapy and biofeedback on psychological coping and the management of pain : an experimental study /." The Ohio State University, 1985. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487259580262508.
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Skidmore, Amanda R. "IMPACT OF SELECTED INTEGRATED PEST MANAGEMENT TECHNIQUES ON ARTHROPODS IN CUCURBIT PRODUCTION SYSTEMS." UKnowledge, 2018. https://uknowledge.uky.edu/entomology_etds/44.
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Cucurbits (i.e. squash, melons, pumpkins, gourds) are high value crops of global importance. Insect pests in these systems are often controlled by chemical insecticides, which are not always effective and can be damaging to the environment. Many integrated pest management (IPM) techniques have been developed for the control of pests in these systems, with a goal of improving system stability and reducing chemical inputs. The overarching goal of my research was to investigate the impact of select IPM techniques on arthropod populations and yield in organic and conventional cucurbit systems.
This dissertation can be divided into three major projects which were conducted between 2013 and 2017. First, an investigation was conducted to understand the impact of two commonly used IPM practices (tillage regime and the use of row covers) on pest insect populations, beneficial arthropod populations, and plant yield. By developing studies in both organic and conventionally managed squash and melon production, four independent studies were conducted and analyzed to provide a broad understanding of these IPM strategies. In all systems, plant yields and pests were greatest in the plasticulture systems, but reduced tillage had a positive impact on the natural enemy arthropods within these crops. Row cover use resulted in larger plants and increased yields, but had an inconsistent influence on arthropods in the systems studied.
From these initial studies, an additional investigation was developed to better understand the impacts of cultivation on the specialist pollinator Peponapis pruinosa [Hymenoptera: Apidae]. Nesting site selection was examined in two independent experiments. By conducting choice studies to allow P. pruinosa to select preferred nesting sites, we determined that P. pruinosa prefer to build nests in loose soils and show reduced nest making in compact soils. This poses interesting management challenges since less-compact soils are within high tillage zones. This research supports the need for the development of cultivation management plans that consider of pollinator habitat and reproduction needs.
A multi-year, multi-farm study was developed for the comparison of parasitism in cucumber beetles (Acalymma vittatum and Diabrotica undecimpunctata) in organic and conventional growing systems. Parasitoids were reared from beetles collected from working organic and conventional cucurbit farms in central Kentucky. Our results show that there is some seasonal variation in parasitism, but that there is no significant difference between organic and conventional production.
We conclude that IPM techniques can be effective in contributing to the control cucurbit pests in agroecosystems and the improvement of crop yields. These studies show that natural enemies and pollinators react differently to IPM practices, which should be considered when developing IPM plans in cucurbit production. By researching these management techniques we are able to develop production systems that have increased stability.
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Halvarsson, Björn. "Interaction Analysis in Multivariable Control Systems : Applications to Bioreactors for Nitrogen Removal." Doctoral thesis, Uppsala universitet, Avdelningen för systemteknik, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-122294.
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Many control systems of practical importance are multivariable. In such systems, each manipulated variable (input signal) may affect several controlled variables (output signals) causing interaction between the input/output loops. For this reason, control of multivariable systems is typically much more difficult compared to the single-input single-output case. It is therefore of great importance to quantify the degree of interaction so that proper input/output pairings that minimize the impact of the interaction can be formed. For this, dedicated interaction measures can be used. The first part of this thesis treats interaction measures. The commonly used Relative Gain Array (RGA) is compared with the Gramian-based interaction measures the Hankel Interaction Index Array (HIIA) and the Participation Matrix (PM) which consider controllability and observability to quantify the impact each input signal has on each output signal. A similar measure based on the <img src="http://www.diva-portal.org/cgi-bin/mimetex.cgi?%5Cmathcal%20H_2" /> norm is also investigated. Further, bounds on the uncertainty of the HIIA and the PM in case of uncertain models are derived. It is also shown how the link between the PM and the Nyquist diagram can be utilized to numerically calculate such bounds. Input/output pairing strategies based on linear quadratic Gaussian (LQG) control are also suggested. The key idea is to design single-input single-output LQG controllers for each input/output pair and thereafter form closed-loop multivariable systems for each control configuration of interest. The performances of these are compared in terms of output variance. In the second part of the thesis, the activated sludge process, commonly found in the biological wastewater treatment step for nitrogen removal, is considered. Multivariable interactions present in this type of bioreactor are analysed with the tools discussed in the first part of the thesis. Furthermore, cost-efficient operation of the activated sludge process is investigated.
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Krieger, Gail D. R. "Reduction of hyperactivity using progressive muscle relaxation imagery and autogenic exercises with electromyographic biofeedback /." The Ohio State University, 1985. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487261919112687.
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Otsuki, Hatsune. "Interactions between Spider Mites and Predators in Systems with Dispersal Opportunities." Kyoto University, 2020. http://hdl.handle.net/2433/253311.
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Kyoto University (京都大学)<br>0048<br>新制・課程博士<br>博士(農学)<br>甲第22475号<br>農博第2379号<br>新制||農||1074(附属図書館)<br>学位論文||R2||N5255(農学部図書室)<br>京都大学大学院農学研究科地域環境科学専攻<br>(主査)教授 日本 典秀, 教授 田中 千尋, 准教授 刑部 正博<br>学位規則第4条第1項該当
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Madeira, Nogueira Filipe. "Movement of predators in arable crop systems." Doctoral thesis, Universitat de Lleida, 2014. http://hdl.handle.net/10803/285265.
Full textAbstract:
L`abundància i dispersió d`O. majusculus no va ser diferent entre parcel-les de panís amb moderadament alta o baixa densitat de males herbes. Els caràbids, C. fuscipes, P. rufipes, P. cupreus i Metallina sp. i l`antocòrid O. majusculus presenten moviment bidireccional entre cultius adjacents de alfals i panís durant l'estació. En contrast, C. septempunctata només es va moure des de l`alfals cap al panís. Els individus d'O. majusculus i C. septempunctata que van colonitzar el panís a l'estadi vegetatiu provenien de l`alfals, indicant que l`alfals va ser la font d'aquests depredadors. No obstant, en el període reproductiu, el panís va actuar com una font de C. fuscipes, P. rufipes, P. cupreus, Metallina sp. i O. majusculus cap a l`alfals, principalment després de dall. El moviment de caràbids, estafilínids i aranyes va ser més intens des dels cereals d'hivern cap als hàbitats semi naturals que des dels prats cap als hàbitats semi naturals, indicant que l'hàbitat adjacent modela el moviment dels depredadors cap als hàbitats semi naturals.<br>La abundancia y dispersión de O. majusculus no fué diferente entre parcelas de maíz con moderada alta o baja densidad de las malas hierbas. Los carábidos, C. fuscipes, P. rufipes, P. cupreus y Metallina sp. y el anthocorido O. majusculus presentan movimiento bidireccional entre cultivos adyacentes de alfalfa y maíz durante la estación. En contraste, C. septempunctata sólo se movió desde la alfalfa hacia al maíz. Los individuos de O. majusculus y C. septempunctata que colonizaron el maíz en el estadio vegetativo provinieron de la alfalfa, indicando que la alfalfa actúo como fuente de estos depredadores. Sin embargo, en el período reproductivo, el maíz actuó como una fuente de C. fuscipes, P. rufipes, P. cupreus, Metallina sp. y O. majusculus hacia la alfalfa, principalmente después de corte. El movimiento de carábidos, estafilínidos y arañas fué más intenso desde los cereales de invierno hacia los hábitats seminaturales que desde los prados hacia a los hábitats semi-naturales, indicando que el hábitat adyacente moldea el movimiento de los depredadores hacia los hábitats seminaturales adyacentes.<br>The abundance and dispersal activity of O. majusculus were not different in maize plots with moderately high or low weed density. The carabids C. fuscipes, P. rufipes, P. cupreus and Metallina sp. and the anthocorid O. majusculus presented bidirectional movements between adjacent alfalfa and maize crops during the season. In contrast, C. septempunctata only moved from alfalfa to maize. The plant-dwelling O. majusculus and C. septempunctata that colonized maize at early vegetative stages came from alfalfa, indicating that alfalfa acted as a source of predators towards maize. However, in the reproductive growth stage period, maize acted as a source for C. fuscipes, P. rufipes, P. cupreus, Metallina sp. and O. majusculus moving to alfalfa, mainly after cuttings. After an alfalfa cutting, margins also acted as a refuge for carabids. Spillover of carabids, rove beetles and spiders was stronger from winter cereals to semi-natural habitats than from meadows to semi-natural habitats, indicating that neighbourhood identity shapes spillover effects to adjacent semi-natural habitats.
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Schembre, Susan M. "Development and validation of a weight-related behaviors questionnaire /." View online ; access limited to URI, 2009. http://0-digitalcommons.uri.edu.helin.uri.edu/dissertations/AAI3368004.
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Stucky-Ropp, Renée C. "Short-term biofeedback-assisted relaxation in persons with rheumatoid arthritis /." free to MU campus, to others for purchase, 1997. http://wwwlib.umi.com/cr/mo/fullcit?p9841185.
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Johnson, Robert Jean. "Plant growth regulators : an alternative to frequent mowing /." Thesis, Monterey, California : Naval Postgraduate School, 1990. http://handle.dtic.mil/100.2/ADA232051.
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Thesis (M.S. in Management)--Naval Postgraduate School, June 1990.<br>Thesis Advisor(s): Carrick, Pual M. "June 1990." Description based on signature page. DTIC Identifier(s): Plant growth regulators, growth indicators. Author(s) subject terms: Plant growth regulators, growth indicators. Includes bibliographical references (p. 39-40). Also available online.
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Borrell, Joseph W. Jantzen Kelly J. "Large scale neural dynamics of rhythmic sensorimotor coordination and stability /." Online version, 2010. http://content.wwu.edu/cdm4/item_viewer.php?CISOROOT=/theses&CISOPTR=326&CISOBOX=1&REC=18.
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Peixoto, Magda da Silva. "Sistemas dinamicos e controladores fuzzy : um estudo da dispersão da morte subita dos citros em São Paulo." [s.n.], 2005. http://repositorio.unicamp.br/jspui/handle/REPOSIP/307553.
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Orientadores: Laecio Carvalho de Barros, Rodney Carlos Bassanezi<br>Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Matematica, Estatistica e Computação Cientifica<br>Made available in DSpace on 2018-08-04T02:48:57Z (GMT). No. of bitstreams: 1
Peixoto_MagdadaSilva_D.pdf: 4244795 bytes, checksum: 6ed64db20c222bb5bb2e020084610233 (MD5)
Previous issue date: 2005<br>Resumo: A Morte Súbita dos Citros é uma doença que afeta e mata laranjeiras doces e as tangerineiras Cmvo e Ponkan enxertadas sobre limoeiros Cmvo e Volkameriano, que representam cerca de 85% dos pomares cítricos de São Paulo e sul do Triângulo Mineiro. Acredita-se que tal doença seja causada por vírus transmitidos por pulgões (vetor) de citros. Para estudar a disseminação da doença propomos um modelo de simulação a partir de autômatos celulares, o qual leva em conta o efeito do vento nas distâncias alcançadas pelo pulgão. Para estabelecer a relação entre espaço percorrido pelo vetor e a intensidade do vento utilizamos um sistema baseado em regras fuzzy. Para estudar a densidade populacional dos pulgões, levamos em conta que eles têm a joaninha como principal predador natural. Estabelecemos uma base de regras fuzzy para modelar a interação pulgões e joaninhas. As trajetórias obtidas no plano de fase são comparadas com as de um modelo determinístico presa-predador do tipo Holling- Tanner e também a um modelo determinístico presa-predador de Lotlm- Volterra. A partir dos resultados obtidos, iniciamos um estudo para investigar alguma política de controle da Morte Súbita dos Citros<br>Abstract: Citrus Sudden Death is a relatively new disease that has affected and killed sweet oranges grafted on the Rangpur lime. This is a worrying characteristic because the Rangpur lime amounts to 85% of the citrus orchards in São Paulo and the south of "Triângulo Mineiro". It is believed that the disease is caused by a virus transmitted by citrus aphids (vectors). We have adopted the Cellular Automata model to study the advance of the disease, which considers the effect of the wind in the distances reached by the aphids. We have adopted the rule-based fuzzy system to establish the relationship between the space covered by the vector and the intensity of the wind. To study the population density of aphids, we have considered that the ladybug is its main enemy. The trajectories of the phase-plane are compared to those of deterministic predatorprey models of the Holling- Tanner and Lotka- Volterra types. From the obtained results, we have begun a study to investigate some control policies for the Citrus Sudden Death<br>Doutorado<br>Matematica Aplicada<br>Doutor em Matemática Aplicada
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Maluleke, Hanyeleni Mary. "Biological productivity, soil resource use and stalk borer infestation in maize lablab planting date and density intercropping systems." Thesis, University of Limpopo, 2004. http://hdl.handle.net/10386/2030.
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Santos, Lucianna Helene Silva dos. "Teoria de controle ótimo com aplicações a sistemas biológicos." Universidade do Estado do Rio de Janeiro, 2012. http://www.bdtd.uerj.br/tde_busca/arquivo.php?codArquivo=4993.
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Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro<br>Neste trabalho apresentamos as etapas para a utilização do método da Programação
Dinâmica, ou Princípio de Otimização de Bellman, para aplicações de controle ótimo.
Investigamos a noção de funções de controle de Lyapunov (FCL) e sua relação com a
estabilidade de sistemas autônomos com controle. Uma função de controle de Lyapunov
deverá satisfazer a equação de Hamilton-Jacobi-Bellman (H-J-B). Usando esse fato, se
uma função de controle de Lyapunov é conhecida, será então possível determinar a lei
de realimentação ótima; isto é, a lei de controle que torna o sistema globalmente assintóticamente
controlável a um estado de equilíbrio. Como aplicação, apresentamos uma
modelagem matemática adequada a um problema de controle ótimo de certos sistemas
biológicos. Este trabalho conta também com um breve histórico sobre o desenvolvimento
da Teoria de Controle de forma a ilustrar a importância, o progresso e a aplicação das
técnicas de controle em diferentes áreas ao longo do tempo.<br>This dissertation presents the steps for using the method of Dynamic Programming
or Bellman Optimization Principle for optimal control applications. We investigate the notion
of control-Lyapunov functions (CLF) and its relation to the stability of autonomous
systems with control. A control-Lyapunov function must satisfy the Hamilton-Jacobi-
Bellman equation (H-J-B). Using this fact, if a control-Lyapunov function is known, it
is possible to determine the optimal feedback law, in other words, the control law which
makes the system globally asymptotically controllable at an equilibrium state. As an
application, we present a mathematical model suitable for an optimal control problem
of certain biological systems. This dissertation also presents a brief historic about the
development of the Control Theory in a way of illustrate the importance and the progress
of the control techniques, specially where it can be applied, according to the diverse areas
and different times that this techniques were discovered and used.
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White, Sacha D. "Implications of new sustainable greenhouse systems for pests, diseases and biological control : a modelling approach using Oidium neolycopersici and Tetranychus urticae." Thesis, University of Warwick, 2012. http://wrap.warwick.ac.uk/50453/.
Full textAbstract:
Concerns regarding carbon emissions, increasing demands on water supplies and environmental pollution have meant that the European protected horticulture industry is being challenged to develop more sustainable greenhouse climate management systems. These new systems can however potentially impact on pest and disease (P & D) pressures and the efficacy of biological control agents (BCAs). This thesis aimed to use a combination of experimental work and simulation models to compare novel and traditional greenhouse climate management scenarios in Spain and the Netherlands using two model P & D systems. These were Oidium neolycopersici (powdery mildew) and its BCA, Bacillus subtilis, on tomato, and Tetranychus urticae (the two-spotted spider mite) and its BCA, Phytoseiulus persimilis, on ornamentals. Experiments showed that latent period, disease development and sporulation of Oidium neolycopersici were strongly influenced by temperatures between 10-33°C and that the control efficacy of B. subtilis was significantly influenced by temperature and humidity in the ranges 10-33°C and 50-95% RH. The functional response of P. persimilis was found to be significantly affected by ambient humidities of 57-99% RH, with predation highest at 85% RH and lowest below 76% RH. These results, in combination with existing data, were used to construct dynamic P & D models. A greenhouse climate model, based on observed temperatures in European greenhouses, was constructed to provide data on the diurnal and seasonal variation in temperature and humidity for different climate management scenarios. The predictions from the P & D models allowed climate control regimes in different greenhouses in Spain and the Netherlands to be identified, which minimised P & D pressures and maximised the efficacy of the BCAs. The implications of these findings for greenhouse climate management are discussed.
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Redlich, Sarah [Verfasser], Ingolf [Gutachter] Steffan-Dewenter, and Ricarda [Gutachter] Scheiner. "Opportunities and obstacles of ecological intensification: Biological pest control in arable cropping systems / Sarah Redlich ; Gutachter: Ingolf Steffan-Dewenter, Ricarda Scheiner." Würzburg : Universität Würzburg, 2020. http://d-nb.info/1221063065/34.
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Sims, Kacee Hall. "Participation of de novo sphingolipid biosynthesis in the regulation of autophagy in response to diverse agents." Diss., Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/42839.
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Sphingolipids are a complex family of molecules that participate in many aspects of cell structure and function, including an essential cellular process known as autophagy. Autophagy is a degradation and recycling pathway whereby intracellular components are sequestered into double-membrane vesicles, known as autophagosomes, for subsequent fusion with lysosomes and degradation. Autophagy takes part in cell survival, host immune defense against pathogens, and other biological processes, but is also sometimes lethal. Ceramide, sphingosine 1-phosphate, and more recently dihydroceramide have been shown to induce autophagy, which opens an interesting new field of cell regulation by sphingolipids. This dissertation describes two new cases in which sphingolipids participate in the induction of autophagy: a) RAW264.7 cells treated with Kdo2-Lipid A, a lipopolysaccharide sub-structure with endotoxin activity equal to LPS; and b) MCF7 cells treated with fenretinde, a chemotherapeutic agent which has shown success in clinical trials. It also analyzes the structural properties of fenretinide that contribute to its ability to modulate sphingolipid metabolism through inhibition of dihydroceramide desaturase, thereby elevating dihydroceramide and induction of autophagy. Autophagy was monitored by following the redistribution of GFP-LC3 into discrete punctate vesicles in response to the agents and by Western blotting; in parallel, the sphingolipid composition of the cells was monitored by liquid chromatography, electrospray ionization tandem mass spectrometry. These analyses revealed that Kdo2-Lipid A and fenretinide induce profound changes in sphingolipid metabolism in RAW264.7 and MCF7 cells, respectively, and that one of the purposes for increased de novo biosynthesis is to enable the production of autophagosomes, as the autophagic response was inhibited by myriocin.
These studies have uncovered a direct link between sphingolipid metabolism and autophagy, which could pave the way for new therapeutic interventions for the treatment of pathogenic infection and be clinically useful in enhancing the efficacy of current cancer treatment strategies.
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Nankinga, Caroline Mary. "Characterization of entomopathogenic fungi and evaluation of delivery systems of Beauveria bassiana for the biological control of the banana weevil, Cosmopolites sordidus." Thesis, University of Reading, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.340485.
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Reid, Michael Steven. "The Role of Heterogeneity in Rhythmic Networks of Neurons." Diss., Georgia Institute of Technology, 2007. http://hdl.handle.net/1853/14565.
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Engineers often view variability as undesirable and seek to minimize it, such as when they employ transistor-matching techniques to improve circuit and system performance. Biology, however, makes no discernible attempt to avoid this variability, which is particularly evident in biological nervous systems whose neurons exhibit marked variability in their cellular properties. In previous studies, this heterogeneity has been shown to have mixed consequences on network rhythmicity, which is essential to locomotion and other oscillatory neural behaviors. The systems that produce and control these stereotyped movements have been optimized to be energy efficient and dependable, and one particularly well-studied rhythmic network is the central pattern generator (CPG), which is capable of generating a coordinated, rhythmic pattern of motor activity in the absence of phasic sensory input. Because they are ubiquitous in biological preparations and reveal a variety of physiological behaviors, these networks provide a platform for studying a critical set of biological control paradigms and inspire research into engineered systems that exploit these underlying principles. We are directing our efforts toward the implementation of applicable technologies and modeling to better understand the combination of these two concepts---the role of heterogeneity in rhythmic networks of neurons. The central engineering theme of our work is to use digital and analog platforms to design and build Hodgkin--Huxley conductance-based neuron models that will be used to implement a half-center oscillator (HCO) model of a CPG. The primary scientific question that we will address is to what extent this heterogeneity affects the rhythmicity of a network of neurons. To do so, we will first analyze the locations, continuities, and sizes of bursting regions using single-neuron models and will then use an FPGA model neuron to study parametric and topological heterogeneity in a fully-connected 36-neuron HCO. We found that heterogeneity can lead to more robust rhythmic networks of neurons, but the type and quantity of heterogeneity and the population-level metric that is used to analyze bursting are critical in determining when this occurs.
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Nersesov, Sergey G. "Nonlinear Impulsive and Hybrid Dynamical Systems." Diss., Georgia Institute of Technology, 2005. http://hdl.handle.net/1853/7147.
Full textAbstract:
Modern complex dynamical systems typically possess a
multiechelon hierarchical hybrid structure characterized by
continuous-time dynamics at the lower-level units and logical
decision-making units at the higher-level of hierarchy. Hybrid
dynamical systems involve an interacting countable collection of
dynamical systems defined on subregions of the partitioned state
space. Thus, in addition to traditional control systems, hybrid
control systems involve supervising controllers which serve to
coordinate the (sometimes competing) actions of the lower-level
controllers. A subclass of hybrid dynamical systems are impulsive
dynamical systems which consist of three elements, namely, a
continuous-time differential equation, a difference equation, and
a criterion for determining when the states of the system are to
be reset. One of the main topics of this dissertation is the
development of stability analysis and control design for impulsive
dynamical systems. Specifically, we generalize Poincare's
theorem to dynamical systems possessing left-continuous flows to
address the stability of limit cycles and periodic orbits of
left-continuous, hybrid, and impulsive dynamical systems. For
nonlinear impulsive dynamical systems, we present partial
stability results, that is, stability with respect to part of the
system's state. Furthermore, we develop adaptive control framework
for general class of impulsive systems as well as energy-based
control framework for hybrid port-controlled Hamiltonian systems.
Extensions of stability theory for impulsive dynamical systems
with respect to the nonnegative orthant of the state space are
also addressed in this dissertation. Furthermore, we design
optimal output feedback controllers for set-point regulation of
linear nonnegative dynamical systems. Another main topic that has
been addressed in this research is the stability analysis of
large-scale dynamical systems. Specifically, we extend the theory
of vector Lyapunov functions by constructing a generalized
comparison system whose vector field can be a function of the
comparison system states as well as the nonlinear dynamical system
states. Furthermore, we present a generalized convergence result
which, in the case of a scalar comparison system, specializes to
the classical Krasovskii-LaSalle invariant set theorem. Moreover,
we develop vector dissipativity theory for large-scale dynamical
systems based on vector storage functions and vector supply rates.
Finally, using a large-scale dynamical systems perspective, we
develop a system-theoretic foundation for thermodynamics.
Specifically, using compartmental dynamical system energy flow
models, we place the universal energy conservation, energy
equipartition, temperature equipartition, and entropy
nonconservation laws of thermodynamics on a system-theoretic
basis.
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Sanches, Paulo Roberto Stefani. "Avaliação de técnicas conservadoras para tratamento da incontinência urinária feminina empregando instrumentação para monitorização domiciliar." Universidade Tecnológica Federal do Paraná, 2008. http://repositorio.utfpr.edu.br/jspui/handle/1/134.
Full textAbstract:
Tratamentos conservadores atuais para incontinência urinária feminina incluem uma combinação de exercícios da musculatura do assoalho pélvico (EMAP), cones vaginais, estimulação elétrica e biofeedback. Todavia, estudos recentes têm sido incapazes de determinar qual técnica suplementar é mais vantajosa. Além disso, a avaliação da adesão ao tratamento é difícil, quando as técnicas são aplicadas em ambiente domiciliar. Assim, os objetivos da pesquisa descrita envolvem o projeto de um equipamento portátil para aplicação de EMAP associados ao biofeedback e à estimulação elétrica em ambiente domiciliar e a realização de estudo piloto em grupo de pacientes com incontinência urinária. O novo equipamento desenvolvido consiste de uma unidade microprocessada portátil com capacidade de memória para armazenar os exercícios realizados pela paciente em ambiente domiciliar. A cada consulta o conteúdo da memória é descarregado via interface serial e pode ser analisado pelo terapeuta, visando a determinação da adesão e performance na realização dos exercícios. A monitorização da pressão de contração da musculatura pélvica é realizada com uma probe vaginal. Foram incluídas no estudo 32 voluntárias, alocadas em 3 grupos de intervenção e submetidas a um protocolo de 13 semanas. Ao início e final do tratamento as voluntárias passaram por avaliação urodinâmica, perineometria e preencheram um diário miccional e questionário de qualidade de vida. A avaliação dos resultados do tratamento mostrou que após 3 meses, 71,9% das pacientes (23) tiveram cura ou melhora significativa, 18,8% (6) melhora parcial de sintomas e 9,3% (3) resposta ruim, sendo encaminhadas para tratamento cirúrgico. A adesão ao tratamento não mostrou diferenças estatisticamente significativas entre os grupos (p=0,201), porém a performance na realização dos exercícios mostrou diferenças significativas (p<0,05), com melhores resultados no grupo de biofeedback. Em todos os grupos, foram observados aumento significativo na força de contração máxima da musculatura pélvica (p<0,05) e uma melhora nos escores do questionário de qualidade de vida (p<0,02). O número de perdas por esforço apresentou uma redução estatisticamente significativa (p<0,05) e observou-se uma tendência de redução no número de micções diárias e número de perdas por urgência. A nova instrumentação desenvolvida para uso domiciliar mostrou-se eficaz e as voluntárias participantes do estudo apresentaram alterações significativas nas variáveis analisadas.<br>Current conservative treatments for female urinary incontinence include a combination of pelvic floor muscle exercises (PFME) and vaginal cones, neuromuscular electrical stimulation and biofeedback. However, recent studies have been insufficient to determine which supplementary technique is more advantageous. In addition, since those techniques are performed at home by the patient, assessment of compliance is difficult. The main goals of this research are the development of a portable device for the treatment of female urinary applying PFME combined with or electrical stimulation and make a pilot study with a patients group. The device developed for this study consists of a microprocessor controlled unit with sufficient memory to store the exercises carried out by patients at home. At each consultation the contents of the memory are downloaded via USB interface for analysis by the therapist. Effective compliance and the quality of the exercises performed can be evaluated. The device includes a vaginal probe for monitoring pelvic muscle contraction pressure during the exercises. The study included 32 patients, allocated to one of 3 intervention groups. Outcomes were: change in quality of life score and in urodynamic and perineometric parameters and changes to urinary habits and episodes of losses recorded in the bladder diary. After 3 months, 71.9 % of the patients (23) had achieved cure or significant improvement, 18.8% (6) partial improvement of symptoms and 9.3 % (3) poor response, being referred for surgical treatment. Compliance with treatment was not different between groups (p=0.201), however the performance in the execution of exercises shows significant differences (p<0.05), with better results in the biofeedback group. In all groups a significant (p<0.05) increase was observed in maximum pelvic muscle contraction strength, in addition to an improvement in the quality of life questionnaire scores (p<0.02). The number of urine losses due to stress exhibited a statistically significant reduction (p<0.05) in all groups. There was a trend towards reduced number of urinations per day and reduced number of urge urine losses. The novel developed instrumentation for home use was efficient and the patients allocated in the research protocol had significant alterations in the assessed variables.