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An Economic Comparison of High Tunnel and Open-Field Strawberry Production in Southeastern Virginia and A Joint Estimation of Acreage Planted to U.S. Major CropsMbarushimana, Jean Claude 07 June 2022 (has links)
This thesis covers two separate studies. The first study, chapter 2, was conducted to evaluate whether there are additional economic returns from producing strawberries in the high tunnel compared to the open-field in Southeast Virginia. We develop and compare budgets for eight strawberry cultivars grown in the two environments and sold under three marketing strategies (pre-pick wholesale, pre-pick retail, and U-pick). Almost all cultivars in the high tunnel generated negative net revenues regardless of the marketing strategy. In contrast, net revenues from open-field cultivars were always positive.
In the second study, chapter 3, we used a fractional multinomial logit model to estimate the effect of crop revenues, input costs, and fuel ethanol production on the joint acreages planted to eight U.S major crops (barley, corn, cotton, peanuts, rice, sorghum, soybeans, and wheat). We found a positive and statistically significant marginal effect of the expected peanuts' revenue on its acreage share. The expected corn revenue had a negative average marginal effect on soybean acreage share, and the effect of expected wheat revenue was positive on cotton acreage share and negative on rice acreage share. / Master of Science / This thesis covers two separate research studies. The first study, chapter 2}, was conducted to evaluate whether growing strawberries in a simple, low-cost, and passive heat structure known as a "high tunnel" would yield more profit (the difference between total revenues and total costs) compared to growing them outside in an open-field in Southeast Virginia. We estimate and compare differences between total revenues and costs for eight strawberry cultivars grown in the two environments and sold under three marketing strategies. The first two marketing strategies involve growers harvesting strawberries themselves. They can then either retail them (farm stands, farmers' markets, or in a similar setting: pre-pick retail) or sell them in bulk to be retailed by others (pre-pick wholesale). A third marketing strategy involves consumers visiting a farm and picking their own strawberries (U-pick). Almost all cultivars grown in the high tunnel structure resulted in a loss (negative difference between total revenues and costs) regardless of the marketing strategy. In contrast, cultivars produced in the open-field always generated a profit (positive total revenues and costs difference).
In the second study, chapter 3, we estimated the effect of crop revenues, input costs, and fuel ethanol production on acreages planted to eight U.S major crops (barley, corn, cotton, peanuts, rice, sorghum, soybeans, and wheat), and we considered the fact that acreages allocated to one crop affect other crops' acreages. We found that increasing the expected revenue of peanuts leads to an increase in its acreage share. Increasing the expected revenue of corn leads to a decrease in soybeans' acreage share. Finally, increasing the expected revenue of wheat leads to an increase in the cotton acreage share and a decrease in the rice acreage share.
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Relative efficacy of nicotinamide treatment of a mouse model of infantile Niemann-Pick C1 diseaseMarshall, Craig A., Borbon, Ivan A., Erickson, Robert P. 25 October 2016 (has links)
Nicotinamide delivered in drinking water at about 2 g/kg/day significantly prolonged survival and showed a suggestive improvement on memory in the Npc1 (nih) / Npc1 (nih) mouse model of infantile NPC1 disease. It is likely that this role is due to its function as a histone deacetylase (HDAC) inhibitor although another HDAC inhibitor, valproic acid, was without effect. Nicotinamide could also work by preventing/reversing oxidative stress.
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Implementing a fast-pick area at Defense Distribution Center San Joaquin (DDJC)Rush, Marvin P., Burks, Eric H. 03 1900 (has links)
Approved for public release; distribution in unlimited. / In a warehouse, a fast-pick-area is a region containing many items that can be retrieved quickly and inexpensively to fulfill customer orders. The Defense Distribution Center San Joaquin (DDJC) implements a similar strategy on a wider scale by designating one of many warehouses as a "fast-pick-area." We develop a plan to optimally slot the fast-pick area at DDJC using a computer model that captures the tradeo.s of storage space versus cost of replenishment from bulk storage. Our results suggest that defense distribution centers should consider implementing a fast pick area as a means of reducing operating costs. / Lieutenant Commander, United States Navy
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Mass Loading of Space PlasmasLidström, Viktor January 2017 (has links)
The solar wind interaction with an icy comet is studied through a model problem. A hybrid simulation is done of a box with evenly distributed water ions and protons, where initially the water ions are stationary, and protons move with the speed of the solar wind. The purpose of the thesis is to investigate the interaction between the two species through the convective electric field, and focus is on early acceleration of pick-up ions, and deflection of the solar wind. It is relevant to the cometary case, because it enables study of the physics of this interaction, without involving other mechanisms, such as bow shock, magnetic field pile-up and draping. The species are found to exchange kinetic energy similar to a damped oscillator, where the dampening is caused by kinetic energy being transferred to the magnetic field. At early times, i.e. times smaller than the gyration time for the water ions, the solar wind does not lose much speed when it is deflected. For comparable number densities, the solar wind can be deflected more than 90° at early times, and loses more speed, and water ions are picked up faster. The total kinetic energy of the system decreases when energy builds up in the magnetic field. The nature of the energy exchange is strongly dependent on the number density ratio between water ions and protons. A density instability with behaviour similar to a plasma beam instability forms as energy in the magnetic field increases, and limits the amount of time the simulation preserves total energy, for the particular hybrid solver used. There is a discussion on the structure of the density instability, and it is compared to cometary simulations.
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Influência do transplante autólogo de células foliculares na formação e funcionalidade de corpo lúteo decorrente da aspiração folicular em ovinos.Denadai, Renan. January 2019 (has links)
Orientador: Sony Dimas Bicudo / Resumo: O objetivo do presente trabalho foi avaliar os corpos lúteos (CL) formados em decorrência da aspiração folicular guiada por laparoscopia (LOPU) na espécie ovina, quanto ao desenvolvimento morfológico, funcionalidade e potencial de desenvolvimento gestacional. Foram realizados dois experimentos, em ambos o estro das ovelhas foi sincronizado utilizando dispositivo intravaginal de acetato de medroxiprogesterona por 14 dias, aplicação de 140 μg cloprostenol no quarto dia e retirada do dispositivo no décimo quarto dia com concomitante administração de gonadotrofina coriônica equina (eCG). No Experimento I, 48 horas após a remoção do dispositivo realizou-se a LOPU dos folículos ovarinos em seis ovelhas (Grupo LOPU – LG), ou a LOPU associada com reposição de células em sete animais (Grupo reposição – RG) em cinco animais a ovulação foi espontânea (Grupo controle – CG). Foi realizada avaliação ultrassonográfica ovariana dos animais diariamente até o momento de uma nova ovulação e coleta de sangue para dosagem de progesterona (P4) plasmática a cada 48 horas até o decimo quinto dia. Os animais do LG (1,7±0,5) e RG (1,4±0,5) formaram mais CLs do que os animais do CG (1,0±0,0). A área lútea individual dos CLs foi menor no LG (0,69±0,30 cm2), em comparação ao RG (0,79±0,25 cm2) e CG (0,85±0,32 cm2). A área lútea total foi semelhante entre o LG (1,2±0,4 cm2) e RG (1,1±0,5 cm2), sendo ambas maiores que a do CG (0,9±0,3 cm2). A concentração de P4 plasmática não diferiu entre os grupos, fican... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The aim of the present study was to evaluate the corpus luteum (CL) formed as a result of laparoscopic ovum pick-up (LOPU) in the ovine, regarding the morphological development, functionality and potential of gestational development. Two experiments were carried out, in both of them, the oestrous of the ewes was synchronized using a 14-day intravaginal device of medroxyprogesterone acetate, 140 μg cloprostenol on the fourth day and withdrawal of the device on the fourteenth day with concomitant administration of equine chorionic gonadotrophin (eCG). In Experiment I, 48 hours after the removal of the device, was realized a LOPU of the ovarian follicles in six sheep (LOPU Group - LG), or LOPU associated with cell replacement in seven animals (Replacement Group - RG) was performed in five animals a ovulation was spontaneous (Control Group - CG). Ultrasonographic evaluation of the animals was performed daily until the time of ovulation and blood collection for progesterone plasma concentration (P4) every 48 hours until the 15th day. LG animals (1.7 ± 0.5) and RG (1.4 ± 0.5) formed more CLs than CG animals (1.0 ± 0.0). The individual luteal area of CLs was lower in LG (0.69 ± 0.30 cm2), compared to RG (0.79 ± 0.25 cm2) and CG (0.85 ± 0.32 cm2). The total luteal area was similar between LG (1.2 ± 0.4 cm2) and RG (1.1 ± 0.5 cm2), both larger than CG (0.9 ± 0.3 cm2). Plasma P4 concentration did not differ between groups, being above 2 ng / mL in the static phase of CLs development. I... (Complete abstract click electronic access below) / Doutor
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Estimation methods in adaptive treatment-selection designsPickard, Michael 08 April 2016 (has links)
Adaptive designs can improve the efficiency of drug development, but further research is needed before some are more widely implemented. One such design is a treatment-selection design, which begins with k treatment arms, but only a subset is carried forward after an interim analysis. The final analysis of the selected arm(s) is then performed using the data from both stages of the study. One issue with this design is ensuring the Type I error rate is controlled, but there have been a number of proposals that largely address this. A second drawback that has not yet been fully addressed is that the maximum likelihood estimate of the selected arm at the final analysis is often biased upward due to the selection method.
Unbiased estimators already exist for this design, but methods with an acceptable balance between bias and mean squared error (MSE) are lacking. In this dissertation, two estimation approaches are proposed. The first is a parametric bootstrap resampling method in which the level of bias adjustment applied is driven by a comparison of the observed results to those expected when all arms have equal true means. The second approach is an empirical Bayes estimator that implements a novel limited translation function. These methods are compared to previously proposed approaches with respect to bias and MSE for studies that have either a normal or binomial endpoint.
Both proposed methods are shown to exhibit reduced bias with reasonable MSE in some simulated scenarios, but the resampling method consistently shows similar, or improved, performance compared to previous approaches across the examined scenarios. The utility of this resampling method is further demonstrated by showing that it can be implemented when the arm with the second largest mean is selected for stage 2. It is also shown that the resampling method can be extended to when more than one arm is selected in stage 1, when there is a futility analysis, or when the study has a time-to-event endpoint. Recommendations on confidence intervals are also provided. The results demonstrate that the parametric bootstrap resampling method is a viable estimation approach for treatment-selection designs.
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Uma solução integrada aplicada ao problema de otimização do ciclo de montagem de uma insersora automática de componentes utilizando uma abordagem híbrida de metaheurísticasBorges, Diogo Alberto 23 March 2009 (has links)
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Previous issue date: 23 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Este trabalho aborda o problema da otimização relacionado ao ciclo de operação de uma insersora automática de componentes (pick-and-place) em máquinas do tipo multi-head. O objetivo consiste em desenvolver uma técnica computacional capaz de encontrar uma boa solução para o problema de otimização, associado ao processo de inserção de componentes. A otimização consiste em resolver de forma conjunta, os Problemas de Escalonamento das Ferramentas, de Escalonamento da Seqüência de Inserção de Componentes e por fim, o Problema da Alocação dos Componentes no Alimentador, visando a redução do tempo total de operação. Como resultados, a técnica computacional permite elevar a produtividade das máquinas onde a mesma é aplicada. Neste trabalho, foi desenvolvida uma aplicação híbrida das metaheurísticas Busca Tabu e Algoritmos Genéticos. Através do uso de uma abordagem diferenciada e utilizando metaheurísticas contemporâneas, bons resultados são apresentados ao longo do trabalho. / This work approaches the optimization Problem related to the operation cycle in an automatic multi-head SMT placement machine (pick-and-place). The objective of this work is developing a computational technique capable to find a good solution for the optimization problem associated with the component insertion process. The optimization process was planned to solve in a joint way the Tools Scheduling Problem, Schedule of Component Insertion Sequence Problem and finally the Component Feeder Allocation Problem. The main objective is to reduce the total operation time. As a result the computational technique can increase the productivity of the machines where it is applied. This study developed a hybrid application of Tabu Search and Genetic Algorithms. The use of a differentiated approach combined with modern metaheuristics, good results are presented in the work.
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O teorema de Pick e aplicaçõesTamari, Márcio Eiji January 2013 (has links)
Orientador: Armando Caputi / Dissertação (mestrado) - Universidade Federal do ABC. Programa de Mestrado Profissional em Matemática em Rede Nacional, 2013
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Pick-Up lines: To Use a Neg or a Flippant?Hendon, Adrienne Leigh 05 May 2012 (has links)
Pick-up lines are a "ritual that tries to turn strangers into lovers" (Murray, 1985, p.17). By studying how pick-up lines are perceived by the population, we might learn how the phenomenon of short- or long-term mating is initiated. By taking into account mating strategies, mate value, attractiveness, and flirting strategies, a pattern of behaviors and reactions may be observed. This study examines perceived pick-up line appropriateness and effectiveness when the attractiveness of the man delivering them varies. To test the effectiveness of 2 different types of pick-up lines, an online survey featuring 1 of 4 videos was administered. Results indicated that a humorous pick-up line was perceived as more effective and favorable than a slightly insulting one. An attractive man was perceived to be more communicatively competent than an unattractive man. Men, regardless of attractiveness, were perceived as more socially attractive when using a humorous pick-up line.
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Weighted interpolation over W*-algebrasGood, Jennifer Rose 01 July 2015 (has links)
An operator-theoretic formulation of the interpolation problem posed by Nevanlinna and Pick in the early twentieth century asks for conditions under which there exists a multiplier of a reproducing kernel Hilbert space that interpolates a specified set of data. Paul S. Muhly and Baruch Solel have shown that their theory for operator algebras built from W*-correspondences provides an appropriate context for generalizing this classic question. Their reproducing kernel W*-correspondences are spaces of functions that generalize the reproducing kernel Hilbert spaces. Their Nevanlinna-Pick interpolation theorem, which is proved using commutant lifting, implies that the algebra of multipliers of the reproducing kernel W*-correspondence associated with a certain W*-version of the classic Szegö kernel may be identified with their primary operator algebra of interest, the Hardy algebra.
To provide a context for generalizing another familiar topic in operator theory, the study of the weighted Hardy spaces, Muhly and Solel have recently expanded their theory to include operator-valued weights. This creates a new family of reproducing kernel W*-correspondences that includes certain, though not all, classic weighted Hardy spaces. It is the purpose of this thesis to generalize several of Muhly and Solel's results to the weighted setting and investigate the function-theoretic properties of the resulting spaces.
We give two principal results. The first is a weighted version of Muhly and Solel's commutant lifting theorem, which we obtain by making use of Parrott's lemma. The second main result, which in fact follows from the first, is a weighted Nevanlinna-Pick interpolation theorem. Other results, several of which follow from the two primary results, include the construction of an orthonormal basis for the nonzero tensor product of two W*-corrrespondences, a double commutant theorem, the identification of several function-theoretic properties of the elements in the reproducing kernel W*-correspondence associated with a weighted W*-Szegö kernel as well as the elements in its algebra of mutlipliers, and the presentation of a relationship between this algebra of multipliers and a weighted Hardy algebra. In addition, we consider a candidate for a W*-version of the complete Pick property and investigate the aforementioned weighted W*-Szegö kernel in its light.
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