2,877 research outputs found
Choroid plexus carcinoma of childhood.
No full textThe presentation, growth patterns, and response to therapy of 11 consecutive children with choroid plexus carcinomas were analyzed, and the results were compared with the outcome reported in other series. Patients were a median of 26 months of age at diagnosis. Two patients had thalamic tumors, one had a posterior fossa primary, and the rest had ventricular lesions. Five of 11 (45%) children remain in continuous progression-free remission a median of 48 months from diagnosis. Four of the five in continuous remission had a "gross total" surgical resection, and only one received radiation therapy. Five of six patients with subtotal resections relapsed despite postoperative treatment with radiation therapy (three) and chemotherapy (one). The response to treatment with radiation therapy or chemotherapy at relapse was disappointing, with only one child (treated with etoposide) responding. In combination with other series, 11 of 14 children had prolonged progression-free survival after gross total resection (only two of whom received adjuvant therapy) compared with two of 20 after less than total resections, independent of the type of adjuvant therapy given. Adjuvant therapy for children with choroid plexus carcinomas is of unproven benefit, and this must be considered when analyzing innovative treatment trials for such children, especially for those with totally resected tumors. Patients with partially resected lesions fare poorly with present forms of treatment
Improved survival with the use of adjuvant chemotherapy in the treatment of medulloblastoma.
No full textBetween 1975 and 1989, 108 children with newly diagnosed medulloblastoma/primitive neuroectodermal tumor (MB/PNET) of the posterior fossa were treated at the authors' institution. The patients were managed uniformly, and treatment included aggressive surgical resections, postoperative staging evaluations for extent of disease, and craniospinal radiation therapy with a local boost. Beginning in 1983, children with MB/PNET were prospectively assigned to risk groups; those with "standard-risk" MB/PNET were treated with radiation therapy alone, while those in the "poor-risk" group received similar radiation therapy plus adjuvant chemotherapy with 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea (CCNU), vincristine, and cisplatin. The 5-year actuarial disease-free survival rate for all patients treated between 1975 and 1982 was 68%, and 73% when patients who died within 2 weeks after operation were excluded. This survival rate was statistically better for patients treated after 1982 (82%) compared to those treated between 1975 and 1982 (49%) (p less than 0.004). There was no difference in disease-free survival rates over time for children with standard-risk factors; however, there was a significant difference in the 5-year survival rate for poor-risk patients treated prior to 1982 (35%) compared to those treated later (87%) (p less than 0.001). For the group as a whole, a younger age at diagnosis correlated with a poorer survival rate; however, this relationship between age and outcome was significant only for children treated before 1983 (p less than 0.001). These results demonstrated an encouraging survival rate for children with MB/PNET, especially those treated with aggressive surgical resection followed by both radiation therapy and chemotherapy. The results strongly suggest that chemotherapy has a role for some, and possibly all, children with MB/PNET
Reformulating the rj-McMC Algorithm for 3D Inversion of Passive Seismic Data for Near-Surface Characterization
No full textGeophysical 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
Which are the most reliable predictors of recurrence of atrial fibrillation after transcatheter ablation?: a meta-analysis.
No full textClowns, 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
No full textThis 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
Risk stratification of medulloblastoma: a paradigm for future childhood brain tumor management strategies.
No full text
Statistical analysis of data from swine feed experiments
No full textNos experimentos de alimentação de suínos em crescimento e acabamento, comumente são obtidos para análise dois conjuntos de dados, o consumo de ração e o ganho de peso, que são correlacionados e, portanto, a análise de qualquer destas variáveis em separado poderá não fornecer informações confiáveis sobre as diferenças entre os tratamentos. Além disso, é prática comum na literatura o uso da análise da variância da conversão alimentar, variável esta que é o quociente do consumo de ração sobre o ganho de peso, com distribuição não normal. Como alternativa, vários autores recomendam o uso do ganho de peso ajustado para o consumo de ração como critério mais correto para avaliar o valor nutricional dos alimentos. Tendo em vista esses aspectos, o presente trabalho foi conduzido visando comparar a sensibilidade em detectar diferenças entre tratamentos pela conversão alimentar, e ganho de peso ajustado por regressão linear e quadrática ao consumo de ração, usando dados reais e simulados. As análises de dados reais mostraram presença de regressão quadrática entre ganho de peso e consumo de ração, através do modelo: yij = u + ti + rj + b1 Xij + b2 X2ij + e ij, onde, yij é o valor observado do ganho de peso, referente ao tratamento i e ao bloco j; u é a mádia geral; ti é o efeito do i-ésimo tratamento; rj é o efeito do j-ésimo bloco; Xij é o consumo de ração referente ao tratamento i e ao bloco j; b1 é o coeficiente de regressão linear de y em relação a x; b2 é o coeficiente de regressão quadrática de y em relação a x; eij é o erro experimental associado a yij, que se supõe com distribuição normal de média zero e variância σ2, ou seja, eij - N(0, σ2). As estimativas dos parâmetros para simulação foram obtidas a partir de vários conjuntos de dados reais. Foram simulados 1.040.000 pares de dados em várias combinações de número de blocos e de tratamentos, com blocos variando entre 2 e 10 e tratamentos entre 2 e 6. Em termos de porcentagem de diferenças significativas observou-se que quando o número de tratamentos é menor ou igual a 3, a conversão alimentar é mais eficiente, e para maior número de tratamentos a análise de covariância e mais eficiente, sendo que a quadrática apresentou pequena vantagem sobre a linear.This study was conducted in order to compare three alternative procedures to evaluate the feed value for the animal in swine feeding experiments: (a) usual analysis of feed conversion given by the ratio of feed intake and body weight gain; (b) body weight gain adjusted to feed intake by linear covariance; (c) body weight gain adjusted to feed intake by quadratic covariance. Preliminar analysis of experimental data indicated a quadratic regression between body weight gain and feed intake that could be described by the model: yij = u + ti + rj + b1 Xij + b2 X2ij + e ij, where: yij = the observed body weight gain in the treatment i and block j; u = the overall mean; ti = effect of treatment I; rj = effect of block j; Xij = the feed intake in the treatment i and block j; b1 = linear regression coefficient of y on x; b2 = quadratic regression coefficient of y on x; eij = experimental error associated with yij distributed as N(0, σ2). Parameters of this model were estimated from experimental data in order to simulate several combinations of block and treatment numbers. Overall, in terms of detecting differences among treatments, the procedure of body weight gain adjusted to feed intake was more efficient than feed conversion, when the number of treatments is greater than three
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