Sensor technology for advanced space missions

The capability and applications of two sensors, Spatial, High-Accuracy, Position-Encoding Sensor (SHAPES) and Fiber Optics Rotation Sensor (FORS), for advanced missions are discussed. The multiple target, 3-D position sensing capability of SHAPES meets a critical technology need for many developing applications. A major milestone of the SHAPES task was completed on schedule on May 30, 1986, by demonstrating simultaneous ranging to eight moving targets at a rate of 10 measurements per second. The range resolution to static target was shown to be 25 microns. SHAPES scheduled technology readiness will support the sensor needs of a number of early users. The next phase in the development of SHAPES is to incorporate an angular measurement CCD to provide the full 3-dimensional sensing. A flight unit design and fabrication can be complete by FY89. FORS, with its significant improvement over present technology in lifetime, performance, weight, power, and recurrent cost, will be an important technology for future space systems. Technology readiness will be demonstrated with a FORS brassboard with fully integrated IO chips by FY88. The unique capability of miniature remote sensing heads, connected to a central system, will open up new areas in control and stability of large space structures. This application requires additional study

Climate science communication on Twitter: A topic modeling analysis of U.S. federal government agencies

Government agencies have a strong role in communicating science and climate change information to the public. However, the characteristics, factors and implications of this behavior have been scarcely examined in the academic literature. In this brief study I address two research questions. First: Can topic modeling analysis via LDA provide valid topics from the Twitter posts of U.S. federal government science agencies? Secondly: How and to what extent is climate change and climate science information being communicated by these agencies under a political administration hostile to climate change science? This study contributes to the literature on the use of topic modeling analysis of social media information in the government context, and to the literature on the politicization of science communication and government communication

Relational Contracts and the Diffusion of Agricultural Technologies in Brazil

WHAT IS the role of the private sector in scaling agricultural technologies in developing countries? The Brazilian experience, with the soybean boom in the savanna and the expansion of the safrinha corn, suggests that the private sector can play a central role in technology diffusion, even in locations where credit and output markets do not function well

Technology Adoption and the Agricultural Supply Response Function

In this study, I exploit the recent technology-driven soy boom in Brazil to assess how the diffusion of different technologies, namely the genetically modified soy and biological nitrogen-fixing soy varieties adapted to the Brazilian savanna, change the agricultural supply response function. I use a novel panel dataset combining farm-level data for 1.5 million commercial farms from the 1996 and 2006 Brazilian agricultural census surveys to estimate the price effects on the expansion of the soy acreage. I find that the acreage response functions become increasingly elastic towards the agricultural frontier because of the existence of different technological diffusion processes. The large price effect on the adoption of nitrogen-fixing soy designed to convert marginal savanna pastureland into soy production explains most of the heterogeneity in the acreage supply function in Brazil. The estimated long-run price elasticity of soy acreage is 0.6 in the south and 1.8 in the savanna. On the agricultural frontier close to the savanna–Amazon border, the price elasticity of agricultural land is 0.13, implying that a 10% permanent increase in soy prices would result in the conversion of 1 million hectares of natural vegetation to farmland

The Distributional Impact of Climate Change in Brazilian Agriculture: A Ricardian Quantile Analysis with Census Data

The economic impact of global warming varies across firms because of differences in climate, technology, and adaptive capacity. Aggregate estimates of the average effect of warming are thus insufficient to model climate change vulnerability in developing countries. In this study, I measure the distributional effect of climate change in Brazilian agriculture by estimating the quantile and interquantile regressions of land value on climate, using agricultural census data for 490,000 commercial farms. The effect of a 1°C rise in average temperature on land values ranges from -5% for the most productive farmers located in the colder South region to -34% for the least productive farmers located in the warmer North region. The impact is most severe in the extreme 0.01 quantile of the land value distribution. The productivity inequality between farms in the extremes of the distribution of land values may double with marginal warming

The Adaptation of Soy-corn Double-cropping to the Brazilian Savanna

TWO REMARKABLE innovations have enabled Brazilian farmers to compete with the soy and corn exports of their US counterparts—breeding soybean varieties for low latitudes using biological nitrogen fixation (BNF) (Hungria, Campos, and Mendes 2001; Alves, Boddey, and Urquiaga 2002; Dobereiner 1997) and the adaptation of a double-cropping soy-corn system for production in the savanna

BRESEX: On board supervision, basic architecture and preliminary aspects for payload and space shuttle interface

Data relative to the on board supervision subsystem are presented which were considered in a conference between INPE and NASA personnel, with the purpose of initiating a joint effort leading to the implementation of the Brazilian remote sensing experiment - (BRESEX). The BRESEX should consist, basically, of a multispectral camera for Earth observation, to be tested in a future space shuttle flight

Sutkutik batel [Retorno] and Yi’bel Kuxlejal [Raíces]

Two poems by Enriqueta Lunez in the Tzotzil language, translated into Spanish by the author, into English by Rosalind Gill, into Portuguese by Lillian DePaula, and into French by Christine Klein-Lataud.Dos poemas de Enriqueta Lunez en lengua tsotsil, traducidos al español por la autora, al inglés por Rosalind Gill, al portugués por Lillian dePaula y al francés por Christine Klein-Lataud.Deux poèmes d'Enriqueta Lunez en tzotzil, traduits en espagnol par l'auteure, en anglais par Rosalind Gill, en portugais par Lillian DePaula et en français par Christine Klein-Lataud.Dois poemas de Enriqueta Lunez na língua tsotsil, traduzidos pela autora para o espanhol, por Rosalind Gill para o inglês, por Lillian DePaula para o português e por Christine Klein-Lataud para o francês