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Precarious lives, practices and spaces : an investigation into homelessness and alternative uses of public spaceGesuelli, Fabrizio January 2018 (has links)
The aim of this doctoral thesis is to investigate the practices of rough sleeping and inhabiting public space, with a focus on the modern city of Rome. By inhabiting public spaces, people who are homeless expose their private sphere to public view. Paradoxically, this public exposure of the private becomes a means of exclusion according to Judith Butler and Athena Athanasiou (2013). Scholars acknowledge public space as constructed by the actions that people carry out in public (Lefebvre 1991; Tschumi 1996; Harvey 2012; Jon Goodbun et al. 2014). People who are homeless certainly contribute to the construction of public space (Petty 2016). However, as asserted by architectural scholar Gill Doron, certain practices 'reveal how the public space is restricted to a very small spectrum of activities, and how many other activities are not permitted' (Doron 2000, p.254). These practices put into question what public these spaces are designed and designated for, questioning why only some activities are regarded as public and why some others take place only at night when spaces are temporary urban voids. Rough sleeping in Rome takes place mostly at night, exposing the city to its own fragilities and contradictions. Public space emerges as precarious. It is defned by social and cultural boundaries, within which urban practices alternate one with the other. These are irreconcilable poles within a parallax gap (Žižek 2009). The theoretical scaffolding of the thesis is structured alongside two other transgressive case studies: Pussy Riot's occupation in Moscow and my interviews with parkour practitioners. These cases have been investigated in comparison with homelessness in order to highlight aspects concerning occupation of space as a performative action under precarious circumstances (precarity). The literary review is combined with auto-ethnographical studies I conducted with a community of rough sleepers, comprising 20-40 members who inhabit a portico area nearby St Peter's Square in Rome. I also ran focus groups, individual interviews and project presentations to people who either are involved in charitable bodies that deal with homelessness or are part of the general public, such as passers-by in St Peter's Square. This study has revealed a series of aspects concerning the negotiation of public space and the role of agency and mediation. This study has stimulated questions concerning the role design can play in discourses of social innovation and inclusion. The research conducted has also outlined diffculties concerning the range of data and the possible response to the many voices heard. How can design re-imagine the centre ground between alternative practices in space? By highlighting the centre as precarious, is it possible to fnd a way of re-thinking the centre? On the basis of this study, the aim of the research has been to look at the state of the gap between these alternative poles, investigating and exploring the concept of precarity. This suggests the possibility of redefning concepts of mediation, social inclusion and architectural activism, articulated further through a series of speculative projects, concluding with the presentation of a 'precarious' object I designed together with the community of rough sleepers in St Peter's Square and COTRAD onlus (a charitable body based in Rome).
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Efeito do substrato e das condições de tratamento do fermento sobre a fermentação etanólica contaminada com leveduras Saccharomyces cerevisiae selvagens e Lactobacillus fermentum / Effect of the substrate and the cell treatment conditions on the ethanolic fermentation contaminated with Saccharomyces cerevisiae wild yeasts and Lactobacillus fermentumVanda Renata Reis 07 April 2016 (has links)
Pouco se sabe sobre o efeito do substrato e a interação entre as leveduras selvagens e bactérias do gênero Lactobacillus na fermentação alcoólica, pois os estudos tem se concentrado na avaliação dos efeitos da contaminação por um ou outro contaminante separadamente. Diante disso, este trabalho teve como objetivos estudar o efeito do substrato e das condições de tratamento do fermento sobre as fermentações contaminadas com ambos os micro-organismos, leveduras S. cerevisiae selvagens (três linhagens apresentando colônias rugosas e células dispostas em pseudohifas) e Lactobacillus fermentum, tendo a linhagem industrial de S. cerevisiae PE-2 como levedura do processo. Foram realizadas fermentações em batelada em mosto de caldo e de melaço, sem reciclo e com reciclo celular, utilizando tanto a cultura pura da linhagem PE-2 quanto as culturas mistas com as linhagens rugosas e ou L. fermentum. Foram avaliadas modificações no tratamento ácido do fermento, visando o controle do crescimento dos contaminantes sem afetar a levedura do processo. Em seguida, foram conduzidas fermentações contaminadas e não contaminadas submetidas ao tratamento ácido combinado com adição de etanol, tanto em caldo quanto em melaço, utilizando-se PE-2, uma das linhagens rugosas e L. fermentum. A atividade da invertase extracelular foi também avaliada em ambos os substratos para os micro-organismos estudados, em condições de crescimento. Concluiu-se que o tipo de substrato de fermentação, caldo de cana ou melaço, influenciou o desempenho da linhagem industrial PE-2 assim como afetou o desenvolvimento das contaminações com as leveduras rugosas S. cerevisiae na presença ou ausência da bactéria L. fermentum, em fermentações sem reciclo celular. O efeito da contaminação foi mais evidente quando se utilizou caldo de cana do que melaço como substrato, no caso da contaminação com leveduras rugosas, e o inverso no caso da contaminação com L. fermentum. O efeito da contaminação sobre a eficiência fermentativa foi maior na presença da levedura rugosa do que com a bactéria, e a contaminação dupla (tanto com a levedura rugosa quanto com a bactéria) não teve efeito maior sobre a eficiência fermentativa do que a contaminação simples, por um ou por outro micro-organismo isoladamente, especialmente na fermentação em batelada com reciclo celular, independentemente do substrato. Nas fermentações com reciclo de células, o efeito do substrato foi menos evidente. O controle do crescimento das linhagens rugosas pode ser realizado modificando o tratamento ácido normalmente realizado na indústria, seja pela adição de etanol à solução ácida ou pelo abaixamento do pH, dependendo da linhagem rugosa. O tratamento combinado baixo pH (2,0) + 13% etanol afetou a fisiologia da linhagem industrial, trazendo prejuízos à fermentação com reciclo celular, com pequeno controle sobre o crescimento da levedura rugosa e causando morte celular à L. fermentum. A diferença na atividade invertásica entre as linhagens rugosas e industrial de S. cerevisiae pode ser a responsável pela fermentação lenta apresentada pelas linhagens rugosas quando presentes na fermentação, sendo não significativa a influência do substrato sobre a atividade dessa enzima. / A little is known about the effect of the substrate and the interaction among wild yeast strains and bacteria Lactobacillus in the alcoholic fermentation, because the studies have been concentrated in the evaluation of the contamination effects by one or another contaminant, separately. This work aimed to evaluate the effect of the substrate and the cell treatment conditions over the batch fermentations contaminated with both microorganisms, yeast wild strains of S. cerevisiae (three strains displaying rough colonies and pseudohyphal cell growth) and Lactobacillus fermentum, being the S. cerevisiae strain PE-2 as the starter yeast. Fermentations using sugarcane juice and molasses, without and with cell recycle, utilizing both the pure culture of PE-2 as the mixed cultures with rough yeast strains and or L. fermentum were carried out. Modifications in the acid cell treatment by the addition of ethanol to the acid solution and the lowering of pH of the acid solution or a treatment with potassium metabisulphite were evaluated, aiming the growth control of the contaminants without affecting the starter yeast. An acid treatment with the addition of 13% ethanol was applied in fermentation with cell recycle, both in sugarcane juice and molasses, utilizing PE-2, one of the rough yeast strains and L. fermentum. The extracellular invertase activity was also evaluated in both substrates for the microorganisms studied, in growing conditions. The type of substrate, sugarcane juice or molasses, influenced the performance of the PE-2 strain as well as affected the development of the contaminations with rough S. cerevisiae yeast strains with or without L. fermentum, in fermentations without cell recycle. The effect of the contamination was more remarkable when sugarcane juice was utilized, in fermentations contaminated with rough yeast strains, but the inverse was observed when L. fermentum was the contaminant. The contamination effect was more harmful with the rough yeast strain than with the bacteria, and the double contamination (with both rough yeast strain and bacteria) did not have a higher effect over the fermentative efficiency than the single contamination, by one or another microorganism in isolation, especially in the batch fermentation with cell recycle, regardless the substrate. In cell-recycled fermentations the effect of the substrate was less evident. The growth control of the rough yeast strains may be done by modifying the acid cell treatment carried out in the industry, both by the addition of ethanol to the acid solution or by the pH lowering, depending on the rough yeast strain. , The combined treatment (pH 2.0 + 13% ethanol) affected PE-2 physiology, bringing about loss in the cell-recycled fermentation, with low growth control of the rough yeast strain but causing cell death of L. fermentum. The difference in the invertase activity between the rough yeast strains and the starter yeast PE-2 may be responsible for the low fermentation rate displayed by the rough yeast strains, but a non significant effect of the substrate on the enzyme activity was observed.
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Development of a Five-Axis Machining Algorithm in Flat End Mill RoughingThompson, Michael Blaine 16 May 2005 (has links)
To further the research done in machining complex surfaces, Jensen [1993] developed an algorithm that matches the normal curvature at a point along the surface with the resultant radius formed by tilting a standard flat end mill. The algorithm called Curvature Matched Machining (CM2) is faster and more efficient than conventional three-axis machining [Jensen 1993, Simpson 1995 & Kitchen 1996]. Despite the successes of CM2 there are still many areas available for research. Consider the machining of a mold or die. The complex nature of a mold requires at least 20-30 weeks of lead time. Of those 20-30 weeks 50% is spent in machining. Of that time 50-65% is spent in rough machining. For a mold or die that amounts to 7 to 8 weeks of rough machining. If one could achieve as much as a 10-15% reduction in machining time that would amount to almost one week worth of time savings. As can be seen, small improvements in time and efficiency for rough machining can yield significant results [Fallbohmer 1996]. This research developed an algorithm that focused on reducing the overall machining time for parts and surfaces. Particularly, the focus of this research was within rough machining. The algorithm incorporated principles of three-axis rough cutting with five-axis CM2, hence Rough Curvature Matched Machining (RCM2). In doing so, the algorithm ‘morphed‘ planar machining slices to the semi-roughed surface allowing the finish pass to be complete in one pass. This roughing algorithm has significant time-savings over current roughing techniques.
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A Learning Approach To Obtain Efficient Testing Strategies In Medical DiagnosisFakih, Saif 15 March 2004 (has links)
Determining the most efficient use of diagnostic tests is one of the complex issues facing the medical practitioners. It is generally accepted that excessive use of tests is common practice in medical diagnosis. Many tests are performed even though the incremental knowledge gained does not affect the course of diagnosis. With the soaring cost of healthcare in the US, there is a critical need for cutting costs of diagnostic tests, while achieving a higher level of diagnostic accuracy. Various decision making tools assisting physicians in diagnosis management have been presented to the literature. One such method, called analytical hierarchy process, utilize a multilevel structure of decision criterion for sequential pair wise comparison of available test choices. Many of the decision-analytic methods are based on Bayes' theory and decision trees. These methods use threshold treatment probabilities and performance characteristics of the tests, such as true-positive rate and false-positive rates, to choose among the available alternatives. Sequential testing approaches tend to elongate the diagnosis process, whereas the parallel testing approach generally involves higher number of tests.
This research is focused on developing a machine learning based methodology for finding an efficient testing strategy for medical diagnosis. The method, based on the patient parameters (both observed and tested), recommends test(s) with the objective of optimizing a measure of performance for the diagnosis process. The performance measure is a combined cost of the testing, the risk and discomfort associated with the tests and the time taken to reach diagnosis. The performance measure also considers the diagnostic ability of the tests.
The methodology is developed combining tools from the fields of data mining (rough set theory, in particular), utility theory, Markov decision processes (MDP), and reinforcement learning (RL). The rough set theory is used in extracting diagnostic information in the form of rules from the medical databases. Utility theory is used to bring three non-homogenous measures (cost of testing, risk and discomfort and diagnostic ability) into one cost based measure of performance. The MDP framework along with an RL algorithm facilitates obtaining efficient testing strategies. The methodology is implemented on a sample problem of diagnosing Solitary Pulmonary Nodule (SPN). The results obtained are compared with those from four other approaches. It is shown that the RL based methodology holds significant promise in improving the performance of diagnostic process.
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Directed polymers and rough pathsTapia Muñoz, Nikolas Esteban January 2018 (has links)
Tesis para optar al grado de Doctor en Ciencias de la Ingeniería, Mención Modelación Matemática / Las Ecuaciones Estocásticas en Derivadas Parciales (SPDEs por su sigla en inglés) son una herramienta esencial para el análisis de los límites de escalamiento de diversos modelos microscópicos provenientes de otras áreas de las ciencias tales como la física y la química.
Este tipo de ecuaciones corresponde a una ecuación en derivadas parciales clásica a la cual se le ha agregado un término de forzamiento externo aleatorio el que suele ser muy irregular; el ejemplo más sencillo es tal vez la Ecuación del Calor Estocástica, de la cual una de sus versiones es estudiada en la presente tesis.
En cualquier caso, la irregularidad de este potencial hace que el análisis de las soluciones de estos problemas sea mucho más complicado.
En efecto, hay casos en que dichas soluciones sólo pueden ser entendidas en el sentido de las distribuciones.
Hay casos más críticos como la ecuación de Kardar--Parisi--Zhang (KPZ) en en una dimensión espacial donde, si bien se puede probar que posee soluciones Hölder, estas no son lo suficientemente regulares para permitir definir uno de los términos no lineales que aparecen en ella.
Durante los últimos 20 años se han desarrollado varias técnicas para el análsis de este tipo de ecuaciones, entre las que destacan la teoría de rough paths geométricos de T. Lyons (1998), los rough paths ramificadosde M. Gubinelli (2010), y la más reciente teoría de estructuras de regularidad de M. Hairer (2014) por la que este último obtuvo la medalla Fields en 2014.
Aunque diferentes, todas estas técnicas tienen como idea central el concepto de renormalización.
En particular, la renormalización de Wick juega un rol esencial en la renormalización en el marco de las estructuras de regularidad.
En este trabajo se desarrollan los productos y polinomios de Wick desde un punto de vista algebraico inspirado en el cálculo umbral de G.-C. Rota.
También se explora la teoría general de losrough paths en general y su versión ramificada en particular, probándose nuevos resultados en la dirección de incorporar un análogo de la renormalización de Wick existente en las estructuras de regularidad.
Por último, se estudia el modelo de polímero semidiscreto multicapas introducido por I. Corwin and A. Hammond (2014) para el cual se prueba la convergencia de su función de partición hacia la "solución" de la Ecuación del Calor Estocástica multicapas definida por N. O'Connell y J. Warren (2011) algunos años antes.
Cabe destacar que al momento de redacción de esta tesis no existen resultados que permitan interpretar este proceso en el continuo como la solución de una SPDE singular como en el caso de la ecuación de KPZ, lo que ha sido una de las principales fuentes de inspiración para este trabajo. / CONICYT/Doctorado Nacional/2013-21130733 CMM - Conicyt PIA AFB170001
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Jämförande studie av LEM2 och Dynamiska Redukter / Comparison of LEM2 and a Dynamic Reduct Classification AlgorithmLeifler, Ola January 2002 (has links)
<p>This thesis presents the results of the implementation and evaluation of two machine learning algorithms [Baz98, GB97]based on notions from Rough Set theory [Paw82]. Both algorithms were implemented and tested using the Weka [WF00]software framework. The main purpose for doing this was to investigate whether the experimental results obtained in [Baz98]could be reproduced, by implementing both algorithms in a framework that provided common functionalities needed by both. As a result of this thesis, a Rough Set framework accompanying the Weka system was designed and implemented, as well as three methods for discretization and three classi cation methods. </p><p>The results of the evaluation did not match those obtained by the original authors. On two standard benchmarking datasets also used previously in [Baz98](Breast Cancer and Lymphography), signi cant results indicating that one of the algorithms performed better than the other could not be established, using the Students t- test and a con dence limit of 95%. However, on two other datasets (Balance Scale and Zoo) differences could be established with more than 95% signi cance. The Dynamic Reduct Approach scored better on the Balance Scale dataset whilst the LEM2 Approach scored better on the Zoo dataset.</p>
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Topics in Soft ComputingKeukelaar, J. H. D. January 2002 (has links)
No description available.
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Nonlinear Interaction Between Ultrasonic Waves and Cracks and InterfacesPoznic, Milan January 2008 (has links)
The subject of this thesis is the development of new ultrasound inspection techniques for detection of cracks that are smaller than the wavelength of the inspecting wave and the characterization of cracks in fluid-filled pipes as either surface-breaking or subsurface. The spectrum of the scattered field of a partially closed crack comprises harmonic components not expected to be found in the case of linear scatterers such as pores or inclusions. Paper A presents an experimental investigation into the linear reflection and generation of the 2nd harmonic component following the incidence of an ultrasonic wave onto a dry or water-confining interface formed by elasto-plastic steel-steel surfaces in contact. The results indicate that water has an unexpected effect on the reflection, at low interfacial pressures, suggesting that fluid mediated forces play a role not accounted for in current models. The level of the generation of the 2nd harmonic measured provides support for further development of the technique for detection of dry, partially closed cracks or fluid-filled, nearly open cracks. A theoretical model describing the nonlinear scattering of acoustic waves by surface-breaking cracks with faces in partial contact is presented in Paper B. Both linear and nonlinear response of the crack are shown to be the largest for a SV wave incident on the surface containing the crack at an angle just above the critical angle for longitudinal waves. A method which provides information on whether a fracture is surface-breaking or subsurface has been modelled and its optimal experimental set-up examined in Paper C. The main assumption of the model is that water carried by pressurized pipes infiltrates and fills a surface-breaking crack, while a subsurface crack is dry. The model simulates an inspection in which the modulation technique is employed and the surface hosting the crack is not accessible. A parameter, constructed with signals recorded in backscattering configuration during a modulation cycle, is examined and shown to provide a clear criterion to distinguish subsurface from surface-breaking cracks when a SV wave at 45 degree incidence is employed as a probe. Finally, in Paper D the modulation technique is experimentally tested on steel beams that host surface-breaking fatigue cracks. The method is shown to be a successful tool to distinguish a dry from a fluid-filled crack. Furthermore, it is revealed that the dynamics of the fluid needs to be accounted for in a more accurate simulation tool. / QC 20100906
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Heat and moisture migration within a porous urea particle bedNie, Xiaodong Rachel 31 August 2010
Urea is an important nitrogen fertilizer for plant nutrition, but is very susceptible to moisture sorption and caking even at low moisture contents, e.g. 0.25% w/w. When urea particles adsorb moisture followed by drying, crystal bridges form between urea particles. For particles
in a bed, this process is called caking. Cakes in stored urea cause a degradation of its quality and value. Investigations of the moisture absorption in beds of manufactured urea particles and adsorption on the external and internal surfaces of urea particles are a necessary step if engineers are to recommend procedures to reduce caking and control inventories.
Research on moisture adsorption and cake strength of urea fertilizer has not been sufficiently explored. Only recently have researchers started to devise tests to investigate the crystal bonding between two urea particles. Prior to this research, investigations of the moisture interactions in beds of urea were nearly non-existent. This thesis presents experimental, theoretical and numerical methods to investigate the coupled heat and moisture transfer processes in a bed of urea particles while the bed is exposed to ambient air with changing temperature and humidity.<p>
Urea particles are nearly spherical with uniform particle size distribution. The particle size, its
internal pore structure and rough crystalline external surface depend on the manufacturing process. In this thesis, two types of urea products are investigated, i.e. prill Georgia urea and granular Terico urea. The rough external surface and internal pore structure of each particle makes the total surface area exposed to water much larger than similar smooth and solid spherical particles. Although Georgia urea has higher external surface area than Terico urea, the latter type has larger total surface area and internal pore volume. For both Terico urea and Georgia, the internal surface area dominates the water sorption process but the external moisture sorption of Georgia urea is more important than that of Terico urea.<p>
All the water vapor interaction experiments were carried out with air flow through a test bed because it shortens the duration of each experiment to a few hours in most cases. A series of experiments with step changes in inlet air temperature and humidity for air flow through a urea bed indicated that the measured outlet air temperature and humidity responses, each at a specific air flow rate, reveals a typical exponential or transient time change that can be
characterized by a time constant.
After formulating the theoretical problem for step changes in the inlet properties, the analytical solutions showed that the time constants of outlet response to whether a temperature step change or a humidity step change are functions of the convection coefficient and air velocity. The predicted outlet air temperature is determined by only one time constant for a temperature step change while it is determined by these two time constants for a humidity step change.<p>
A new test cell with sampling test ports was developed to measure the transient moisture uptake of a urea particle bed and its distribution at any time without any interruption of the experiment. A novel particle sampling device, modified from a syringe and pistons, was designed to minimize the particle exposure to ambient air during the moisture content determination using a Karl Fischer titrator. Data from two continuous cyclic step changes in the inlet flow with relative humidities between 4% and 70% at room temperature showed a hysteresis in the isothermal moisture content for only the first cycle. After the second sorption- desorption cycle, the hysteresis disappeared. This implies that the internal pore and particle surface geometry changes are very slow after the first cycle.<p>
A new theoretical porous media model was developed for a coupled heat and moisture
transport process when humid air flowed uniformly through a large test bed in two coupled computational domains: internal domain (i.e., the particle phase) and the external domain (i.e.,
the interstitial air space). The moisture migration in two computational domains included:
water vapor diffusion inside each particle, and water vapor convection and diffusion in the
interstitial air space in the urea particle bed. For energy transport, the temperature was assumed to be uniform inside each particle, but heat convection and conduction between the urea particles and the interstitial air outside particles occurred throughout the bed. Both heat transfer and mass transfer in internal domain and external domain were coupled by the heat and mass convection at the gas-particle interface. The numerical simulation was compared with the data of moisture uptake and showed good agreement implying that the internal moisture diffusion that dominates the moisture uptake process is a very slow process.<p>
These above experimental, theoretical and numerical research studies provide a set of
information on how urea particles adsorb or desorb moisture from or to ambient air on the
external and internal pore surface, which offers a useful suggestion for urea caking prevention
and is also a first and necessary step to the study of further caking formation and strength.
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Regrowth of <i>Festuca hallii</i> (Vasey Piper) and <i>Stipa curtiseta</i> [(A.S. Hitch.) Barkworth] following defoliation on a hummocky landscape in Central SaskatchewanPantel, Andrew William 20 December 2006
A 4-year study was conducted on the Missouri Coteau in the Mixed Grassland Ecoregion of Saskatchewan to determine the effects of mowing to a 7.5 cm stubble height on the growth of <i>Festuca hallii</i> (Vasey) Piper and <i>Stipa curtiseta</i> (A.S. Hitch.) Barkworth. Green standing crop (GSC), dead standing crop (DSC) and above ground net primary production (ANPP) were compared to an unmowed control after a single mowing in April, May, June, July, August, September, October or November on 5 landforms including north aspect-concave-slope, north aspect-convex-slope, south aspect-concave-slope, south aspect-convex-slope and level upland. Mowing reduced GSC, DSC and ANPP with reductions varying among months of mowing and among landforms. Green standing crop, DSC and ANPP of <i>F. hallii</i> were greatest on the north aspects and least on south aspect-convex slope and ranged from 2 to 122 g m-2, 3 to 121 g m-2, and 8 to 122 g m-2, respectively. Mowing reduced GSC of <i>F. hallii</i> for 1 to 11 growing season months and DSC for 1 to >11 growing season months. Mowing in May or November reduced ANPP of <i>F. hallii</i> for 1 growing season, while mowing in other months reduced ANPP for 2 growing seasons. Green standing crop of <i>S. curtiseta</i>, ranging from 3 g m-2 to 55 g m-2, was least on the north aspects and greatest on the south aspect-convex slope and was reduced 1 to 5 growing season months following mowing. Mowing after June reduced DSC of <i>S. curtiseta</i>(5 to 58 g m-2) for 1 to 10 growing season months, and ANPP (6 to 64 g m-2) for 1 growing season. Generally, mowing reduced GSC, DSC and ANPP of <i>F. hallii</i> longer than <i>S. curtiseta</i>. Production of <i>F. hallii</i>- and <i>S. curtiseta</i>-dominated plant communities in the Northern Mixed Prairie will be maintained by providing rest periods between defoliation events based on the number of growing season months for <i>F. hallii</i> to recover production.
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