2,617 research outputs found

    Matrix Models and A Proof of the Open Analog of Witten’s Conjecture

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    In a recent work, R. Pandharipande, J. P. Solomon and the second author have initiated a study of the intersection theory on the moduli space of Riemann surfaces with boundary. They conjectured that the generating series of the intersection numbers satisfies the open KdV equations. In this paper we prove this conjecture. Our proof goes through a matrix model and is based on a Kontsevich type combinatorial formula for the intersection numbers that was found by the second author

    Reformulating the rj-McMC Algorithm for 3D Inversion of Passive Seismic Data for Near-Surface Characterization

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    Geophysical subsurface characterization techniques could, due to their non-invasive nature, play a crucial role in the design and subsequent construction of infrastructure in urban & industrial environ- ments. Geo-data specialist company Fugro sees potential in upgrading their current ambient-seismic- noise-tomography workflow, to make use of state-of-the-art inversion schemes with the main goal of increasing the quality and accuracy of the initial-site characterization delivered to clients. In this thesis I explore the feasibility of utilizing the reverse-jump Markov chain Monte Carlo (rj-McMC) algorithm for the inversion of ambient seismic noise for characterization in urban & industrial environments. Specif- ically, testing the potential of scaling down this inversion algorithm to fit in a small scale, near-surface framework. To achieve this, I first carried out analyses to evaluate the appropriate Rayleigh wave frequency range, after which realistic noise hyperparameters, suited for this reduced scale problem, were obtained. Because of the potential exploitation of in-situ borehole measurements, I reformulated the Bayesian prior within the rj-McMC algorithm to implement these constraining shear wave velocity values appropriately. I conducted extensive synthetic experiments to gain insight into the behavior of this adapted algorithm, from which it was concluded that the inherent dynamic discretization partially prevents these constraints from being implemented to their full extent. Nevertheless, promising results lead me to conclude that the use of the rj-McMC algorithm for application in near-surface urban & industrial environments is feasible.Applied Geophysics | IDEA Leagu

    Clowns, Fools, and Killers: An Exploration of Horror, Comedy, and Madness Through the Roles of Murderer 2 and Sir Richard Ratcliffe in William Shakespeare\u27s Richard III

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    This document is a thesis submitted in partial fulfillment of the Master of Fine Arts degree in Theatre Arts with a Concentration in Musical Theatre. It is a detailed account of author RJ Magee’s artistic and scholarly process in creating the roles of Murderer 2 and Sir Richard Ratcliffe in William Shakespeare’s Richard III. The production was performed as part of Minnesota State University, Mankato’s mainstage season in October of 2022. In five chapters, this thesis chronicles the actor’s process: a preproduction analysis, a historical and critical perspective, a rehearsal and performance journal, a post-production analysis, and a process development analysis. Appendices and works cited are included

    Refined open intersection numbers and the Kontsevich-Penner matrix model

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    A study of the intersection theory on the moduli space of Riemann surfaces with boundary was recently initiated in a work of R. Pandharipande, J.P. Solomon and the third author, where they introduced open intersection numbers in genus 0. Their construction was later generalized to all genera by J.P. Solomon and the third author. In this paper we consider a refinement of the open intersection numbers by distinguishing contributions from surfaces with different numbers of boundary components, and we calculate all these numbers. We then construct a matrix model for the generating series of the refined open intersection numbers and conjecture that it is equivalent to the Kontsevich-Penner matrix model. An evidence for the conjecture is presented. Another refinement of the open intersection numbers, which describes the distribution of the boundary marked points on the boundary components, is also discussed

    The influence of the implantation of an aquaviary terminal in local dynamics sedimentary f the Guanabara Bay, RJ

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    A Baía da Guanabara vem sofrendo alterações na sua bacia de drenagem desde o início do século XIX que resultaram em acentuada degradação ambiental. O presente trabalho discute a influência da implantação de um Terminal Aquaviário de Gás Natural Liquefeito (GNL) na Baía, e suas possíveis influências nos processos de sedimentação local e/ou re-disponibilização de sedimentos de fundo, e possíveis contaminantes associados. Os resultados dos modelos matemáticos mostram que as maiores velocidades das plumas termicas que atingem o fundo são em média 0,46 m3/s para as simulações de verão e 0,47 m3/s para as simulações de inverno, sendo que são necessários pelo menos de 0,50 m3/s para uma corrente erodir o fundo, porem velocidades na faixa de 20 a 50 m3/s são suficientes para causar erosão de sedimentos finos inconsolidados. Sendo assim, a influência das plumas térmicas geradas no processo de re-gaseificação do GNL é de pequena magnitude, e suas correntes só conseguem exportar estes sedimentos para distancias inferiores a 1000 m. Em relação a re-disponibilização de contaminantes associados aos sedimentos de fundo se mostrou pouco provável, dado o fato da qualidade dos sedimentos apresentarem, diferente da água, baixa concentração de contaminantes e da baixa competência de erosão, que eles tenham competência para erodir sedimentos consolidados.Since the beginning of the XIX century, interventions on the Guanabara\'s Bay drainage basin result in severe environmental degradation. This work aimed to analyze the implementation of an Aquaviary Terminal of Liquefied Natural Gas (LNG), and its putative consequences on the local sedimentation processes, and the availability and possible associated contaminants of the bottom sediments. According to the mathematical models developed, the means of the greatest speeds of the thermal plumes that reach the bottom are 0.46m3/s for the summer simulations and 0.47m3/s for the winter. However, for a current to be able to erode the bottom it must be of at least 50m3/s. Currents with speeds ranging from 20 to 50m3/s are sufficient only to cause the erosion of fine and non-consolidated sediment. Therefore, the thermal plumes generated in the process of re-gasification of the LNG are of little magnitude, and will not be able to export these sediments to any distance greater than 1000 meters. The re-availability of the contaminants associated with the bottom sediments is not likely, once these sediments, differently from the water, showed little concentration of contaminants. In addition, with the low erosion capacity of the currents generated, the consolidated sediments are not likely to be eroded

    Radiation-induced root surface caries restored with glass-ionomer cement placed in conventional and ART cavity preparations: Results at two years

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    The document attached has been archived with permission from the Australian Dental Association (8th Jan 2008). An external link to the publisher’s copy is included.Background: There are no published studies comparing the clinical performances of more-viscous glass-ionomer cement (GIC) restorations when placed using conventional and atraumatic restorative treatment (ART) cavity preparation methods to restore root surface caries. Methods: One dentist used encapsulated Fuji IX GP and Ketac-Molar to restore 72 conventional and 74 ART cavity preparations for 15 patients who had received cervicofacial radiation therapy. Two assessors evaluated the restorations at six, 12, and 24 months for retention, marginal defects and surface wear, and recurrent caries. Results: After two years, the cumulative restoration successes were 65.2 per cent for the conventional and 66.2 per cent for the ART cavity preparations, without statistical or clinical significance (P>0.50). Restoration dislodgement accounted for 82.8 per cent and marginal defects for 17.2 per cent of all failures. There were no instances of unsatisfactory restoration wear or recurrent caries observed. Teeth with three or more restored cervical surfaces accounted for 79.3 per cent of all failures (P<0.0001). Conclusions: For root surface caries restored with GIC, the use of hand instruments only with the ART method was an equally effective alternative to conventional rotary instrumentation for cavity preparation. Larger restorations had higher failures, usually from dislodgement.JY Hu, XC Chen, YQ Li, RJ Smales and KH Yi

    Platelet-rich plasma and macular hole surgery: A clue to their mode of action and the influence of anti-platelet agents

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    \ua9 The Author(s) 2022. Purpose: To present a case of refractory full-thickness macular hole (FTMH), in which autologous platelet-rich plasma (aPRP) was used on two consecutive occasions, and associated with successful closure only after complete cessation of anti-platelet therapy. Methods: Interventional case report. Results: A 63-year-old male with Alport syndrome underwent pars plana vitrectomy with internal limiting membrane peeling and gas for a large FTMH. The patient was on systemic anti-platelet agents for coronary disease. Post-operatively, the FTMH remained open and repeated surgery, augmented with aPRP, was performed. Although a thick pre-retinal coagulum was evident on optical coherence tomography on day one post-surgery, the second surgery failed. Ultimately, successful aPRP-augmented surgical closure of the FTMH was achieved only after complete cessation of systemic anti-platelet agents. Conclusion: Appropriate management of anti-platelet therapy may be relevant when planning aPRP use, though further large-scale studies are needed to assess the precise effect of anti-platelet therapy on the efficacy of aPRP, and to confirm the potential role of aPRP in patients with Alport syndrome

    Needle deflection in thermal ablation procedures of liver tumors: a CT image analysis

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    Introduction: Accurate needle placement is crucial in image-guided needle interventions. A targeting error may be introduced due to undesired needle deflection upon insertion through tissue, caused by e.g. patient breathing, tissue heterogeneity, or asymmetric needle tip geometries. This paper aims to quantify needle deflection in thermal ablation procedures of liver tumors by means of a CT image analysis. Methods: Needle selection was done by using all clinical CT data that were made during thermal ablation procedures of the liver, ranging from 2008-2016, in the Erasmus MC, the Netherlands. The 3D needle shape was reconstructed for all selected insertions using manual segmentation. Subsequently, a straight line was computed between the entry point of the needle into the body and the needle tip. The maximal perpendicular distance between this straight line and the actual needle was used to calculate needle deflection. Results: In total, 365 needles were included in the analysis ranging from 14G to 17G in diameter. Average needle insertion depth was 95mm (range: 32 mm – 182 mm). Needle deflection was on average 1.3 mm (range: 0.0 mm – 6.5 mm). 54% of the needles (n=196) had a needle deflection of more than one millimeter, whereas 7% of the needles (n=25) showed a large needle deflection of more than three millimeters. Conclusions: Needle deflection in interventional radiology occurs in more than half of the needle insertions. Therefore, deflection should be taken into account when performing procedures and when defining design requirements for novel needles. Further, needle insertion models need to be developed that account for needle deflection.Medical Instruments & Bio-Inspired Technolog

    Pharmacological interventions for patients experiencing acute post-operative pain

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    What is pain? It is an unpleasant sensory and emotional experience associated with actual or potential tissue damage. What are goals for postoperative pain management?To increase a patients quality of life, to facilitate a full and healthy recovery, to decrease the risk for complications (Impaired mobility - pneumonia, pressure ulcers, DVT), to allow for early discharge from the hospital. Conclusion: by using a combination of pharmacological interventions we can more accurately provide pain management to patients by addressing multiple types of pain at once. By performing a thorough pain assessment and using our clinical judgement to determine what pharmacological interventions are necessary, we can move closer to achieving our postoperative pain management goals.Not peer reviewedStudent Research Day Poster (2017
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