94 research outputs found

    The Physics of Star Cluster Formation and Evolution

    Get PDF
    © 2020 Springer-Verlag. The final publication is available at Springer via https://doi.org/10.1007/s11214-020-00689-4.Star clusters form in dense, hierarchically collapsing gas clouds. Bulk kinetic energy is transformed to turbulence with stars forming from cores fed by filaments. In the most compact regions, stellar feedback is least effective in removing the gas and stars may form very efficiently. These are also the regions where, in high-mass clusters, ejecta from some kind of high-mass stars are effectively captured during the formation phase of some of the low mass stars and effectively channeled into the latter to form multiple populations. Star formation epochs in star clusters are generally set by gas flows that determine the abundance of gas in the cluster. We argue that there is likely only one star formation epoch after which clusters remain essentially clear of gas by cluster winds. Collisional dynamics is important in this phase leading to core collapse, expansion and eventual dispersion of every cluster. We review recent developments in the field with a focus on theoretical work.Peer reviewe

    A model for drug dispensing service based on the care process in the Brazilian health system

    Get PDF
    Access to medication emphasizes the availability of the product at the expense of providing a service. The goal of this paper is to propose a theoretical model for a drug dispensing service, beginning with a reflection on the current realities of the Unified Health System and drug dispensation in Brazil. A conceptual analytical research made by a methodological course called disciplined imagination was mainly the approach applied to develop the model. The drug dispensing service is part of the care process, which considers access as an attribute; reception, connection and accountability, management, and clinical pharmaceutical aspects as components; and the rational use of drugs as the purpose. The proposed model addresses access to the dispensing service and demands a reorientation of routines, instruments, and practices.O acesso a medicamentos enfatiza a disponibilidade do produto em detrimento da provisão de um serviço. O objetivo deste trabalho é propor um modelo teórico para um serviço de dispensação de medicamentos, iniciando com uma reflexão sobre a realidade atual do Sistema Único de Saúde e a dispensação de medicamentos no Brasil. Uma pesquisa analítica conceitual realizada por meio de um percurso metodológico chamado de imaginação disciplinada constituiu a estratégia principal para o desenvolvimento do modelo. O serviço de dispensação é parte do processo de cuidado, o qual considera o acesso como um atributo; os aspectos acolhimento, vínculo e responsabilização, gestão e clínica farmacêutica como componentes e o uso racional de medicamentos como o propósito. O modelo proposto direciona o acesso para o serviço de dispensação e demanda a reorientação de rotinas, instrumentos e práticas

    More than 10,000 pre-Columbian earthworks are still hidden throughout Amazonia

    Get PDF
    Indigenous societies are known to have occupied the Amazon basin for more than 12,000 years, but the scale of their influence on Amazonian forests remains uncertain. We report the discovery, using LIDAR (light detection and ranging) information from across the basin, of 24 previously undetected pre-Columbian earthworks beneath the forest canopy. Modeled distribution and abundance of large-scale archaeological sites across Amazonia suggest that between 10,272 and 23,648 sites remain to be discovered and that most will be found in the southwest. We also identified 53 domesticated tree species significantly associated with earthwork occurrence probability, likely suggesting past management practices. Closed-canopy forests across Amazonia are likely to contain thousands of undiscovered archaeological sites around which pre-Columbian societies actively modified forests, a discovery that opens opportunities for better understanding the magnitude of ancient human influence on Amazonia and its current state
    corecore