A treatment planning intercomparison of proton and intensity modulated photon radiotherapy.

peer reviewedAbstract Purpose: A comparative treatment planning study has been undertaken between standard photon delivery techniques,b intensity modulated photon methods and spot scanned protons in order to investigate the merits and limitations of each of these treatment approaches. Methods: Plans for each modality were performed using CT scans and planning information for nine patients with varying indications and lesion sites and the results have been analysed using a variety of dose and volume based parameters. Results: Over all cases, it is predicted that the use of protons could lead to a reduction of the total integral dose by a factor three compared to standard photon techniques and a factor two compared to IM photon plans. In addition, in all but one Organ at Risk (OAR) for one case, protons are predicted to reduce both mean OAR dose and the irradiated volume at the 50% mean target dose level compared to both photon methods. However, when considering the volume of an OAR irradiated to 70% or more of the target dose, little difference could be shown between proton and intensity modulated photon plans. On comparing the magnitude of dose hot spots in OARs resulting from the proton and IM photon plans, more variation was observed, and the ranking of the plans was then found to be case and OAR dependent. Conclusions: The use of protons has been found to reduce the medium to low dose load (below about 70% of the target dose) to OARs and all non-target tissues compared to both standard and inversely planned photons, but that the use of intensity modulated photons can result in similar levels of high dose conformation to that afforded by protons. However, the introduction of inverse planning methods for protons is necessary before general conclusions on the relative efficacy of photons and protons can be drawn

Simulation of truncated normal variables

We provide in this paper simulation algorithms for one-sided and two-sided truncated normal distributions. These algorithms are then used to simulate multivariate normal variables with restricted parameter space for any covariance structure.Comment: This 1992 paper appeared in 1995 in Statistics and Computing and the gist of it is contained in Monte Carlo Statistical Methods (2004), but I receive weekly requests for reprints so here it is

Harmonic BRST Quantization of Systems with Irreducible Holomorphic Boson and Fermion Constraints

We show that the harmonic Becchi-Rouet-Stora-Tyutin method of quantizing bosonic systems with second-class constraints or first-class holomorphic constraints extends to systems having both bosonic and fermionic second-class or first-class holomorphic constraints. Using a limit argument, we show that the harmonic BRST modified path integral reproduces the correct Senjanovic measure.Comment: 11 pages, phyzz

Developing Feasible and Effective School-Based Interventions for Children With ASD: A Case Study of the Iterative Development Process

Despite an emphasis on identifying evidence-based practices among researchers and using evidence-based practices among professionals in the field of education, there are still problems with uptake and implementation in real-world settings. This lack of diffusion of practices is evident in educational programming for children with autism spectrum disorder (ASD). One solution is to use an iterative process to develop interventions in which researchers work in collaboration with the end users to test and refine interventions. However, there are very few guidelines for developing feasible and effective interventions through these iterative processes. This article provides a description of the iterative process used to develop the Advancing Social-Communication and Play (ASAP) intervention, a supplemental program designed for public preschool classrooms serving students with ASD, and examples of how data from the sequence of iterative design studies shaped the intervention development. The research team offers guidelines for other researchers looking to engage in intervention development using an iterative process in the context of partnerships with end users, including suggestions for planning and executing an intervention development grant

Avaliação de estratégias de produção em agricultura irrigada no perímetro de irrigação do Gorutuba.

Apresenta-se aqui o relatório de projeto de pesquisa, parcialmente financiado pelo Conselho Nacional de Desenvolvimento Científico e Tecnológico, CNPq, que teve como objetivo gerar uma base de informações para dar suporte a decisões relativas ao manejo da irrigação e ao planejamento para o perímetro de irrigação do Gorutuba. O relatório compreende o período de 10 de agosto de 2005 a 10 de agosto de 2007. Informações técnicas e econômicas de cinco culturas perenes e quinze anuais foram levantadas na literatura internacional, nacional e local e em relatórios do distrito de irrigação Gorutuba e da Codevasf. Séries históricas de dados de clima foram obtidas na Embrapa Milho e Sorgo. Amostras de solo foram coletadas em quatro propriedades representativas de pequeno e grande produtor e as análises físicas e químicas realizadas nos laboratórios da Embrapa. Os coeficientes técnicos dos custos de produção foram obtidos junto ao distrito de irrigação Jaíba, sendo considerados similares aos verificados no perímetro Gorutuba. Consideraram-se valores médios para os custos dos fatores de produção para o Norte de Minas Gerais, atualizados para dezembro de 2006. Consideraram-se os custos de água de irrigação praticados no perímetro e os preços de venda dos produtos foram ajustados com base em uma série histórica, corrigida pelo IPCA, obtida junto aos distritos de irrigação, Emater-MG e Codevasf e preços recebidos no Ceasa-MG, em diferentes épocas do ano. Os requerimentos totais de irrigação (RIT) e as produtividades relativas totais (YRT) foram obtidos mediante simulações com o modelo MCID. Posteriormente, essas informações foram empregadas nos estudos de otimização de padrão de cultivo, associados à análise de risco, na definição de coeficientes técnicos relativos à função objetivo e na definição de restrições no modelo de programação linear. Visando demonstrar a aplicação das ferramentas de otimização de padrão de cultivo e de requerimento de água, foram construídos dois modelos de programação linear (MPL), sendo que a cada um destes MPL ?s foi associada uma análise de risco. Para proceder as análises de risco empregou-se o programa P-Risco, no qual algumas variáveis de entrada e de saída são estocásticas, tendo a elas associada uma distribuição de probabilidade. Duas propriedades, uma de 200 ha e outra de 11 ha, foram utilizadas como estudos de caso, com base em cenários de produção hipotéticos. As análises demonstraram a capacidade das ferramentas propostas para o planejamento e para o auxílio à tomada de decisões em propriedades de perímetros irrigados.bitstream/item/61027/1/doc-73.pd

State-of-the-art report: Intergenerational linkages in families

__Abstract__ We present a state-of-the-art of the literature on linkages between generations within families. We focus specifically on intergenerational coresidence, upward and downward intergenerational transfers in families and the relationship between norms of family obligation and intergenerational transfers. An overview of the academic literature on these topics is provided, as well as suggestions for future research

Analytical approaches for transplant research

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73605/1/j.1600-6135.2004.00402.x.pd

D3-brane action in a supergravity background: the fermionic story

Using the kappa-symmetric action for a D3-brane, we study the interaction between its world-volume fermions and a bosonic type IIB supergravity background preserving 4-dimensional Lorentz invariance. We find that the renormalizable terms in the action include only coupling between the fermions and the 3-form flux in the combination *G_3-iG_3, which is zero for a class of supersymmetric and nonsupersymmetric solutions. We also find the magnetic and electric dipole moments for the fermions, which are proportional to the derivative of the dilaton-axion. We show that different gauges to fix the kappa-symmetry give the same interaction terms, and prove that these terms are also SL(2,R) self-dual. We interpret our results in terms of N=1 supersymmetric gauge theory on the D-brane.Comment: 23 pages. Minor corrections, references adde