989 resultados para Earth and Atmospheric Sciences
Resumo:
Modern methods of compositional data analysis are not well known in biomedical research. Moreover, there appear to be few mathematical and statistical researchers working on compositional biomedical problems. Like the earth and environmental sciences, biomedicine has many problems in which the relevant scienti c information is encoded in the relative abundance of key species or categories. I introduce three problems in cancer research in which analysis of compositions plays an important role. The problems involve 1) the classi cation of serum proteomic pro les for early detection of lung cancer, 2) inference of the relative amounts of di erent tissue types in a diagnostic tumor biopsy, and 3) the subcellular localization of the BRCA1 protein, and it's role in breast cancer patient prognosis. For each of these problems I outline a partial solution. However, none of these problems is \solved". I attempt to identify areas in which additional statistical development is needed with the hope of encouraging more compositional data analysts to become involved in biomedical research
Resumo:
Geological and geomorphological maps are, apart from a source of scientific information, a necessary tool in order to take proper decisions to solve the geo-environmental problems that arise when dealing with territorial planning. In this paper, the social and economical utility of such maps is described, and some exercises meant for Science of Earth and Environmental Sciences students are proposed
Resumo:
Surface roughness is an important geomorphological variable which has been used in the Earth and planetary sciences to infer material properties, current/past processes, and the time elapsed since formation. No single definition exists; however, within the context of geomorphometry, we use surface roughness as an expression of the variability of a topographic surface at a given scale, where the scale of analysis is determined by the size of the landforms or geomorphic features of interest. Six techniques for the calculation of surface roughness were selected for an assessment of the parameter`s behavior at different spatial scales and data-set resolutions. Area ratio operated independently of scale, providing consistent results across spatial resolutions. Vector dispersion produced results with increasing roughness and homogenization of terrain at coarser resolutions and larger window sizes. Standard deviation of residual topography highlighted local features and did not detect regional relief. Standard deviation of elevation correctly identified breaks of slope and was good at detecting regional relief. Standard deviation of slope (SD(slope)) also correctly identified smooth sloping areas and breaks of slope, providing the best results for geomorphological analysis. Standard deviation of profile curvature identified the breaks of slope, although not as strongly as SD(slope), and it is sensitive to noise and spurious data. In general, SD(slope) offered good performance at a variety of scales, while the simplicity of calculation is perhaps its single greatest benefit.
Resumo:
Seamounts are of great interest to science, industry and conservation because of their potential role as 'stirring rods' of the oceans, their enhanced productivity, their high local biodiversity, and the growing exploitation of their natural resources. This is accompanied by rising concern about the threats to seamount ecosystems, e.g. through over-fishing and the impact of trawling. OASIS described the functioning characteristics of seamount ecosystems. OASIS' integrated hydrographic, biogeochemical and biological information. Based on two case studies. The scientific results, condensed in conceptual and mass balanced ecosystem models, were applied to outline a model management plan as well as site-specific management plans for the seamounts investigated. OASIS addressed five main objectives: Objective 1: To identify and describe the physical forcing mechanisms effecting seamount systems Objective 2: To assess the origin, quality and dynamics of particulate organic material within the water column and surface sediment at seamounts. Objective 3: To describe aspects of the biodiversity and the ecology of seamount biota, to assess their dynamics and the maintenance of their production. Objective 4: Modelling the trophic ecology of seamount ecosystems. Objective 5: Application of scientific knowledge to practical conservation.
Resumo:
En Argentina, desde comienzos del presente siglo, las políticas científicas y tecnológicas explícitas evidencian un claro interés en la producción de conocimientos orientados a la resolución de problemas sociales, productivos y medioambientales de carácter local. Desde la bibliometría se vienen realizando estudios sobre la producción científica de los países, existiendo varios antecedentes que enfocan la atención en la producción científica argentina. Sin embargo, son incipientes y escasos los trabajos sobre la producción científica enfocada a temas locales. Los objetivos de esta investigación son analizar y describir la relación entre lo local y lo global en la producción científica argentina con visibilidad en Scopus en el período 2008-2012, y comparar indicadores de publicación, colaboración y liderazgo desde las dimensiones nacionales e internacionales de las prácticas de comunicación científica. Los resultados muestran ;que una cuarta parte de la producción está orientada a temas locales, con destacada presencia de contribuciones en Ciencias sociales, Economía y Administración, Ciencias agrícolas y biológicas, Ciencias de la tierra y relacionadas con el ambiente. Un alto porcentaje de esta producción se publica en revistas extra-regionales. Hay un mayor predominio de investigación en colaboración nacional y sin colaboración en los temas locales. Sin embargo casi un tercio de la producción se realizó en colaboración internacional, con diferencias porcentuales según las disciplinas. Por último, destaca el alto porcentaje de producción liderada por investigadores de instituciones argentinas en todas las disciplinas, tanto en los temas locales como globales