670 research outputs found
Diversidade, Biogeografia e Conservação das Begoniaceae no Estado do Espírito Santo, Brasil
A família Begoniaceae é representada no Brasil pelo gênero Begonia com aproximadamente 215 espécies encontradas principalmente na Mata Atlântica em todas as formações florestais exceto o mangue. No Espírito Santo restam aproximadamente 11% da cobertura vegetal original constituída de fragmentos de diferentes tamanhos que guardam parte da riqueza e diversidade da biota capixaba.
Os objetivos deste estudo foram levantar as espécies de Begonia ocorrendo no estado do Espírito Santo, caracterizar as formações vegetais onde elas ocorrem, analisar os padrões de distribuição geográfica, diversidade e riqueza, distribuição nas Unidades de Conservação de Proteção Integral e áreas indicadas como Prioritárias para Conservação da Biodiversidade no Espírito Santo, definir o status de conservação e inferir similaridade das espécies do Espírito Santo com os outros estados brasileiros. A metodologia usada foi a comumente utilizada em levantamento florístico e taxonomia de fanerógamas, levantamento bibliográfico, consulta a herbário, observação e coleta no campo. No Espírito Santo foram encontradas 53 espécies de Begonia, sendo quatro novas para a ciência. Três táxons foram sinonimizados e um reabilitado. Dessas espécies 42 ocorrem em Floresta Ombrófila Densa, quatro em Floresta Estacional Semidecidual e quatro simultaneamente nas duas formações vegetais. Três espécies têm ocorrência nos Neotropicos, três são endêmicas da America do Sul, duas ocorrem no Brasil extra-amazônico, 45 são endêmicas da Mata Atlântica e 18 são endêmicas do Espírito Santo, sendo duas microendémicas. Segundo os critérios da IUCN, 11 espécies são consideradas Criticamente em Perigo, nove Em Perigo, cinco Vulnerável e duas Extintas na Natureza. Ainda são fornecidas, chave de identificação, descrições, distribuição, habitat, etimologia, comentários, mapas e Ilustrações
Global versus local billiard level dynamics: The limits of universality
Level dynamics measurements have been performed in a Sinai microwave billiard
as a function of a single length, as well as in rectangular billiards with
randomly distributed disks as a function of the position of one disk. In the
first case the field distribution is changed globally, and velocity
distributions and autocorrelation functions are well described by universal
functions derived by Simons and Altshuler. In the second case the field
distribution is changed locally. Here another type of universal correlations is
observed. It can be derived under the assumption that chaotic wave functions
may be described by a random superposition of plane waves
Energetic charged particle fluxes relevant to Ganymede's polar region
The JEDI instrument made measurements of energetic charged particles near Ganymede during a close encounter with that moon. Here we find ion flux levels are similar close to Ganymede itself but outside its magnetosphere and on near wake and open field lines. But energetic electron flux levels are more than a factor of 2 lower on polar and near-wake field lines than on nearby Jovian field lines at all energies reported here. Flux levels are relevant to the weathering of the surface, particularly processes that affect the distribution of ice, since surface brightness has been linked to the open-closed field line boundary. For this reason, we estimate the sputtering rates expected in the polar regions due to energetic heavy ions. Other rates, such as those related to radiolysis by plasma and particles that can reach the surface, need to be added to complete the picture of charged particle weathering
TRY plant trait database - enhanced coverage and open access
Plant traits-the morphological, anatomical, physiological, biochemical and phenological characteristics of plants-determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait-based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits-almost complete coverage for 'plant growth form'. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait-environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives
Zur Entwicklung der Technologie des Holzes und technologische Entwicklungen in der Holzwirtschaft – von der Vergangenheit zur Zukunft
Callisto's Atmosphere and Its Space Environment: Prospects for the Particle Environment Package on Board JUICE
The JUpiter ICy moons Explorer (JUICE) of the European Space Agency will investigate Jupiter and its icy moons Europa, Ganymede, and Callisto, with the aim to better understand the origin and evolution of our Solar System and the emergence of habitable worlds around gas giants. The Particle Environment Package (PEP) on board JUICE is designed to measure neutrals and ions and electrons at thermal, suprathermal, and radiation belt energies (eV to MeV). In the vicinity of Callisto, PEP will characterize the plasma environment, the outer parts of Callisto's atmosphere and ionosphere and their interaction with Jupiter's dynamic magnetosphere. Roughly 20 Callisto flybys with closest approaches between 200 and 5,000 km altitude are planned over the course of the JUICE mission. In this article, we review the state of the art regarding Callisto's ambient environment and magnetospheric interaction with recent modeling efforts for Callisto's atmosphere and ionosphere. Based on this review, we identify science opportunities for the PEP observations to optimize scientific insight gained from the foreseen JUICE flybys. These considerations will inform both science operation planning of PEP and JUICE and they will guide future model development for Callisto's atmosphere, ionosphere, and their interaction with the plasma environment
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