Adaptive Imaging Methods using a Rotating Modulation Collimator (RMC)

The Rotating Modulation Collimator (RMC) belongs to a larger class of radiation imaging systems that rely on either temporal or spatial modulation of incident radiation through collimation to map the location of the incident radiation source. The strengths of these detection systems include their low cost and simplicity. A major drawback is the collection time required for low radiation intensities due especially to the loss of radiation information resulting from collimation. One method of addressing this drawback for the RMC is by applying an adaptive imaging approach. As with most system design theory, there are inherent design tradeoffs for the RMC. By using different RMC configurations for the same radiation environment observation, these tradeoffs can be wagered against one another to improve overall performance. This research explores the effect of RMC configuration changes, specifically by changing the mask design, sampling method, and the angle between the image plane and the RMC centerline

Application of the immunoregulatory receptor LILRB1 as a crystallisation chaperone for human class I MHC complexes

X-ray crystallographic studies of class I peptide-MHC molecules (pMHC) continue to provide important insights into immune recognition, however their success depends on generation of diffraction-quality crystals, which remains a significant challenge. While protein engineering techniques such as surface-entropy reduction and lysine methylation have proven utility in facilitating and/or improving protein crystallisation, they risk affecting the conformation and biochemistry of the class I MHC antigen binding groove. An attractive alternative is the use of noncovalent crystallisation chaperones, however these have not been developed for pMHC. Here we describe a method for promoting class I pMHC crystallisation, by exploiting its natural ligand interaction with the immunoregulatory receptor LILRB1 as a novel crystallisation chaperone. First, focussing on a model HIV-1-derived HLA-A2-restricted peptide, we determined a 2.4 Å HLA-A2/LILRB1 structure, which validated that co crystallisation with LILRB1 does not alter conformation of the antigenic peptide. We then demonstrated that addition of LILRB1 enhanced the crystallisation of multiple peptide-HLA-A2 complexes, and identified a generic condition for initial co-crystallisation. LILRB1 chaperone-based crystallisation enabled structure determination for HLA-A2 complexes previously intransigent to crystallisation, including both conventional and post-translationally-modified peptides, of diverse lengths. Since both the LILRB1 recognition interface on the HLA-A2 α3 domain molecule and HLA-A2 mediated crystal contacts are predominantly conserved across class I MHC molecules, the approach we outline could prove applicable to a diverse range of class I pMHC. LILRB1 chaperone-mediated crystallisation should expedite molecular insights into the immunobiology of diverse immune-related diseases and immunotherapeutic strategies, particularly involving class I pMHC complexes that are challenging to crystallise

Optimal L2-norm empirical importance weights for the change of probability measure

This work proposes an optimization formulation to determine a set of empirical importance weights to achieve a change of probability measure. The objective is to estimate statistics from a target distribution using random samples generated from a (different) proposal distribution. This work considers the specific case in which the proposal distribution from which the random samples are generated is unknown; that is, we have available the samples but no explicit description of their underlying distribution. In this setting, the Radon–Nikodym theorem provides a valid but indeterminable solution to the task, since the distribution from which the random samples are generated is inaccessible. The proposed approach employs the well-defined and determinable empirical distribution function associated with the available samples. The core idea is to compute importance weights associated with the random samples, such that the distance between the weighted proposal empirical distribution function and the desired target distribution function is minimized. The distance metric selected for this work is the L[subscript 2] -norm and the importance weights are constrained to define a probability measure. The resulting optimization problem is shown to be a single linear equality and box-constrained quadratic program. This problem can be solved efficiently using optimization algorithms that scale well to high dimensions. Under some conditions restricting the class of distribution functions, the solution of the optimization problem is shown to result in a weighted proposal empirical distribution function that converges to the target distribution function in the L[subscript 1] -norm, as the number of samples tends to infinity. Results on a variety of test cases show that the proposed approach performs well in comparison with other well-known approaches.Singapore University of Technology and Design. International Design CenterUnited States. Defense Advanced Research Projects Agency (META program through AFRL Contract FA8650-10-C-7083 and Vanderbilt University Contract VUDSR#21807-S7)United States. Federal Aviation Administration. Office of Environment and Energy (FAA Award No. 09-C-NE-MIT, Amendment Nos. 028, 033, and 038

The first records of Red-legged Crake Rallina fasciata for Cambodia

First paragraph: The Red-legged Crake Rallina fasciata is a little-known rallid, listed as Least Concern by BirdLife International (2015), with a range extending across most of South-East Asia (Robson 2008, Taylor 2015). However, the species has been rarely recorded, with the exception of a few locations in Singapore and Thailand (Li 2009, Wong 2011, Pierce et al. 2013), partly because of its skulking nature; it is seldom flushed or observed, and very rarely encountered as camera-trap by-catch during wildlife surveys, indicating that it may indeed be genuinely scarce. This note is a compilation of the only three confirmed Redlegged Crake records from Cambodia. Two are new records, whilst the third has been previously reported (Goes 2013) but is presented here with documentary evidence. These records confirm the species’s presence in three protected areas in widely separated parts of the country, and offer limited but important information on its ecology and likely status

Endividamento forçado, Big Government e implausibilidade de crise no capitalismo: um exercício a partir de um modelo de consistência entre fluxos e estoques

The aim of this paper is describe Steindl.s .enforced indebtedness. in a closed system through a stock-flow consistent framework. Begining with an accounting framework that allow us to analyze in a consistent way stocks and flow variables we show that the .enforced indebtedness. and the possibility of crisis become absolutely implausible when we think about the role played by Minsky.s Big Government. The public sector should do expansive fiscal policies avoiding the aggregate profit reduction, the increase in the indebtedness rate and the fall in aggregate investment. Following the functional finance approach, government would not find any obstacle to finance its deficits because private sector will always accept government debt in the form of high-powered money and bonds issued by it.Este trabalho tem como objetivo descrever o processo de endividamento forçado de Steindl em uma economia fechada a partir de um modelo de consistência entre fluxos e estoques. Partimos de esquema contábil que nos permite analisar, de forma consistente, as variáveis de fluxo e sua contrapartida em termos dos estoques e, com base nele, mostramos que esse processo e a possibilidade de crise se tornam absolutamente implausíveis se pensarmos no papel exercido pelo Big Government de Minsky. O setor público pode fazer políticas fiscais expansivas, evitando que os lucros caiam, que a taxa de endividamento se eleve e que o investimento caia. Para isso, seguindo a abordagem das .finan- ças funcionais., o governo não encontrará qualquer obstáculo para se financiar, porque o público sempre aceita a moeda e a dívida pública emitida por ele. Palavras-chave Endividamento forçado; .política fiscal.; finanças funcionai

Review of participation in Seminário BNDES de Manufatura Avançada

Inclui bibliografia

A decomposition-based uncertainty quantification approach for environmental impacts of aviation technology and operation

As a measure to manage the climate impact of aviation, significant enhancements to aviation technologies and operations are necessary. When assessing these enhancements and their respective impacts on the climate, it is important that we also quantify the associated uncertainties. This is important to support an effective decision and policymaking process. However, such quantification of uncertainty is challenging, especially in a complex system that comprises multiple interacting components. The uncertainty quantification task can quickly become computationally intractable and cumbersome for one individual or group to manage. Recognizing the challenge of quantifying uncertainty in multicomponent systems, we utilize a divide-and-conquer approach, inspired by the decomposition-based approaches used in multidisciplinary analysis and optimization. Specifically, we perform uncertainty analysis and global sensitivity analysis of our multicomponent aviation system in a decomposition-based manner. In this work, we demonstrate how to handle a high-dimensional multicomponent interface using sensitivity-based dimension reduction and a novel importance sampling method. Our results demonstrate that the decomposition-based uncertainty quantification approach can effectively quantify the uncertainty of a feed-forward multicomponent system for which the component models are housed in different locations and owned by different groups. Keywords: Aviation Environmental Impact; Decomposition; Global Sensitivity Analysis; Uncertainty Quantificatio

O modelo de dois hiatos e o supermultiplicador

Neste trabalho reavaliamos criticamente o modelo de dois hiatos de Chenery. Tentaremos mostrar que o modelo original de Chenery tinha um caráter normativo, pois era um modelo de planejamento, e que o modelo foi desenvolvido precisamente para dizer que a restrição externa em geral era a mais relevante. No caso da literatura brasileira a partir dos anos 80, o modelo foi usado como um modelo positivo de uma economia não planejada e em geral com o objetivo de argumentar que a restrição mais relevante era (e é) a de poupança. Mostramos também que numa economia não planejada, no que diz respeito ao hiato de poupança, a operação do mecanismo do supermultiplicador garante que mesmo a longo prazo a taxa de poupança é determinada endogenamente pela taxa de investimento. Por outro lado, quanto à restrição de divisas, mostraremos que na economia não planejada ela não deve ser formalizada como um limite ao investimento e sim ao nível de atividade em geral.

Reflexões críticas sobre a experiência brasileira de política industrial no setor eólico

Bibliografia: p. 217-219In the past few decades many national economies have heavily fostered renewable energy and clean technologies. The investments made were supported by strong public policy to promote energy security and independence, the transition to a green economy, stimulate job creation, spur innovation and economic growth. In this paper, we present a critical review of the public policy and its main mechanisms used in Brazil to develop a local wind industry, taking as reference the US and China experiences. The combination between energy policy and industrial policy is explored. We highlight the relevance of a sizeable and stable domestic demand of wind turbines connected to the public financing of wind farms and localization standards to promote a local manufacturing supply chain.O desenvolvimento da geração de energia limpa de fontes renováveis e de novas tecnologias para o combate à mudança climática tem servido como plataforma para a estruturação de políticas que promovam a transição para uma matriz energética mais limpa, a segurança energética, a geração de emprego e renda, o progresso técnico, a inovação e o desenvolvimento econômico. O presente artigo propõe algumas reflexões críticas sobre as políticas públicas adotadas para o desenvolvimento da energia eólica no Brasil à luz das experiências norte-americana e chinesa. A articulação das políticas energéticas às políticas industriais e a estruturação de mecanismos de indução da demanda por energia eólica e de exigência de contrapartidas de localização associadas ao financiamento público dos parques de geração são abordadas em detalhes

The capital goods industry: diagnosis of the 2000-2012 period and perspectives based on the Brazilian economic scenario

For several reasons the capital goods industry (CGI) is strategic for Brazil. This study aims to analyze this industry’s recent behavior in a period when the Brazilian economy regained momentum. We will evaluate some opportunities for several segments in the Brazilian economy by breaking down investment into several activities while we simultaneously evaluate the Brazilian capital goods industry’s ability to benefit from these mentioned opportunities. Data from IBGE and MDIC will be used in this study and also from Capital Flow Tables (CFT) and from BNDES’ operations and estimates of future investments