121 research outputs found
Spectroscopy of D-type asteroids
We have performed a spectroscopic survey of 19 D-type asteroids. Comparison with previous photometry shows excellent agreement. Although the majority have similar colors to cometary nuclei, no cometary emission bands were present in any of the spectra. Absorption bands sporadically appearing were apparently due to stellar objects, and no features inherent to the asteroids were observed
Philosophy and updating of the asteroid photometric catalogue
The Asteroid Photometric Catalogue now contains photometric lightcurves for 584 asteroids. We discuss some of the guiding principles behind it. This concerns both observers who offer input to it and users of the product
Urban Sprawl and Adverse Impacts on Agricultural Land: A Case Study on Hyderabad, India
Many Indian capitals are rapidly becoming megacities due to industrialization and rural–urban emigration. Land use within city boundaries has changed dynamically, accommodating development while replacing traditional land-use patterns. Using Landsat-8 and IRS-P6 data, this study investigated land-use changes in urban and peri-urban Hyderabad and their influence on land-use and land-cover. Advanced methods, such as spectral matching techniques with ground information were deployed in the analysis. From 2005 to 2016, the wastewater-irrigated area adjacent to the Musi river increased from 15,553 to 20,573 hectares, with concurrent expansion of the city boundaries from 38,863 to 80,111 hectares. Opportunistic shifts in land-use, especially related to wastewater-irrigated agriculture, emerged in response to growing demand for fresh vegetables and urban livestock feed, and to easy access to markets due to the city’s expansion. Validation performed on the land-use maps developed revealed 80–85% accuracy
The Role of Health Systems Factors in Facilitating Access to Psychotropic Medicines: A Cross-Sectional Analysis of the WHO-AIMS in 63 Low- and Middle-Income Countries
In a cross-sectional analysis of WHO-AIMS data, Ryan McBain and colleagues investigate the associations between health system components and access to psychotropic drugs in 63 low and middle income countries
Percepção dos consumidores relativamente à carne de bovino: critérios de escolha a partir de grupos de discussão
Nas economias desenvolvidas, a segurança dos alimentos, o bem‑estar animal e o ambiente tĂŞm vindo a assumir relevância nas preocupações dos consumidores. Procurámos saber, atravĂ©s da metodologia dos grupos de discussĂŁo (focus groups) realizados em duas cidades de Portugal, Lisboa e Porto, as preocupações e perceções dos consumidores relativamente a estes atributos, os quais sĂŁo essencialmente acreditados. Este conhecimento Ă© fundamental para a aplicação posterior de mĂ©todos de preferĂŞncias declaradas. Foi ainda possĂvel obter, com base em exercĂcios de seleção entre carnes diferenciadas, e atravĂ©s de um modelo logit, intervalos de preços passĂveis de serem utilizados posteriormente na definição de cenários em experiĂŞncias de escolha (mĂ©todo de preferĂŞncias declaradas) -----ABSTRACT-----In developed economies, food safety, animal welfare and the environment have become relevant consumers’ concerns. We conducted several focus groups in two Portuguese cities, Lisboa and Porto, in order to get participants perceptions and concerns for these attributes, which are essentially credence attributes. This knowledge is critical for the subsequent application of stated preference methods. It was also possible to estimate, based on exercises of selection among different meats, and through a logit model, price ranges that could be used in the definition of scenarios for choice experiments (stated preference method)info:eu-repo/semantics/publishedVersio
Physical studies of asteroids. X. Photoelectric light curves of the asteroids 219 and 512
The recent capture of periodic comet P/Scotti (2000 Y3)
Numerical integrations of 99 orbits centered on that of comet P/Scotti (P/2000 Y3), and of the nominal orbit, were made 4000 days backwards in time, and 7300 days into the future. The integrations show that this comet has been transferred in its present orbit as recently as 1998. The future orbital evolution indicates a stable period for almost 150 years, when another close encounter with Jupiter may lead to further drastic changes of the present orbit
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