31,979 research outputs found
Descritores mínimos indicados para caracterizar cultivares/variedades de feijão comum (Phaseolus vulgaris L.).
O objetivo deste trabalho foi descrever os descritores mínimos e sua metodologia utilizados para fins de proteção de cultivares de feijão.bitstream/CNPAF/23834/1/doc_184.pd
Comportamento fisiológico de sementes de Harrisia adscendens (Gurke) Britto et Rose (cactaceae) submetidas a diferentes temperaturas e tratamentos.
Seismic vulnerability assessment of the old city centre of Seixal, Portugal
The seismic vulnerability assessment of old traditional masonry building stocks, in a seismic risk mitigation perspective, is truly essential not only for buildings with recognized historical and patrimonial value, but also, in relation to regular buildings. In this sense, this paper approaches the issue of the seismic vulnerability assessment of masonry buildings through the application of a simplified methodology to building stock of the old city centre of Seixal, Portugal. This methodology is based on a vulnerability index, suitable in the evaluation of damage and in the creation of large scale loss scenarios (economical and human). Over 500 buildings were evaluated in accordance with the referred methodology and the results obtained were then integrated into a Geographical Information System tool. The integration of this kind of vulnerability and loss results into a GIS tool allows that city councils or regional authorities make their decisions based on a global view of the site under analysis, which led to more accurate and faster decisions either in terms of risk mitigation strategies or rehabilitation plans. This tool can also assumes great importance in the construction of safety and rescue plans
Vulnerability assessment of urban building stock: a hierarchic approach
In the last decades the evaluation of the seismic risk are of rising concern, considered essential in the activity and
definition of strategy planning and urban management. The evaluation of the seismic vulnerability of the existent building stock
in the perspective of the seismic risk mitigation should not be placed only in relation to the isolated buildings of relevant
historical and cultural importance, but also, in relation to the agglomerate of buildings in urban centres. The chronological
construction process frequently results in characteristic heterogeneity of masonry and wall connection quality. In addition,
buildings do not constitute independent units given that they share the mid-walls with adjacent buildings and the façade walls are
aligned. This way, as post-seismic observations proved, buildings do not have an independent structural behaviour, but they
interact amongst themselves, mainly for horizontal actions and so the structural performance should be studied at the level of the
aggregate and not only for each isolated building. In most cases, for masonry structures there is no need for sophisticated
dynamic analyses for seismic resistance verification or vulnerability assessment. This is even more relevant when an assessment
at the level of a city centre is pursued. In this work, the results of evaluation of the vulnerability will be presented in accordance
to three proposed methodologies based on a vulnerability index that consequently allows the evaluation of damage and creation
of loss scenarios (economical and human) not only at the level of the building and its façade walls but also at the level of the
aggregates. It will be discussed and evaluated the application of the referred methodologies and its integration in an SIG
platform
Biologia floral de Mandevilla leptophylla (A. DC.) K.Schum (Apocynaceae) na região de Petrolina – PE.
Type A GABA-receptor-dependent synaptic transmission sculpts dendritic arbor structure in Xenopus tadpoles in vivo.
The emergence of dendritic arbor structure in vivo depends on synaptic inputs. We tested whether inhibitory GABAergic synaptic transmission regulates Xenopus optic tectal cell dendritic arbor development in vivo by expressing a peptide corresponding to an intracellular loop (ICL) of the γ2 subunit of GABAAR which is required to anchor GABAA receptors to the postsynaptic scaffold. GFP-tagged ICL (EGFP-ICL) was distributed in a punctate pattern at putative inhibitory synapses, identified by VGAT-immunoreactive puncta. ICL expression completely blocked GABAAR - mediated transmission in 36% of transfected neurons and significantly reduced GABAAR - mediated synaptic currents relative to AMPAR-mediated synaptic currents in the remaining transfected neurons without altering release probability or neuronal excitability. Further analysis of ICL-expressing neurons with residual GABAAR- mediated inputs showed that the capacity of benzodiazepine to enhance GABAergic synaptic responses was reduced in ICL-expressing neurons, indicating that they were likely depleted of γ2 subunit-containing GABAAR. Neurons expressing a mutant form of ICL were comparable to controls. In vivo time-lapse images showed that ICL-expressing neurons have more sparsely branched dendritic arbors which expand over larger neuropil areas than EGFP-expressing control neurons. Analysis of branch dynamics indicated that ICL expression affected arbor growth by reducing rates of branch addition. Furthermore, we found that decreasing GABAergic synaptic transmission with ICL expression blocked visual experience dependent dendritic arbor structural plasticity. Our findings establish an essential role for inhibitory GABAergic synaptic transmission in the regulation of dendritic structural plasticity in Xenopus in vivo
Graded-index optical fiber emulator of an interacting three-atom system: illumination control of particle statistics and classical non-separability
We show that a system of three trapped ultracold and strongly interacting
atoms in one-dimension can be emulated using an optical fiber with a
graded-index profile and thin metallic slabs. While the wave-nature of single
quantum particles leads to direct and well known analogies with classical
optics, for interacting many-particle systems with unrestricted statistics such
analoga are not straightforward. Here we study the symmetries present in the
fiber eigenstates by using discrete group theory and show that, by spatially
modulating the incident field, one can select the atomic statistics, i.e.,
emulate a system of three bosons, fermions or two bosons or fermions plus an
additional distinguishable particle. We also show that the optical system is
able to produce classical non-separability resembling that found in the
analogous atomic system.Comment: 14 pages, 5 figure
Fichas de inspecção e registo: gestão integrada de informação sobre o edificado antigo do Seixal
A inspecção constitui a primeira tarefa na avaliação da condição de um edifício, compreendendo desde logo a identificação e o registo das suas anomalias de carácter estrutural e não estrutural. No caso particular dos edifícios antigos, e devido ao desconhecimento generalizado das técnicas e materiais de construção tradicionais, estas acções de inspecção revelam-se frequentemente inadequadas, comprometendo desta forma a formulação de um diagnóstico assertivo e a eficiência de eventuais acções de reabilitação ou reforço.
As fichas de inspecção e registo assumiram-se desde sempre como uma das primeiras opções no conjunto das ferramentas de avaliação e diagnóstico das construções existentes, tanto na inferência das suas condições de habitabilidade, como no apoio a acções de avaliação imobiliária e patrimonial a diferentes escalas.
Neste artigo apresentam-se os resultados do desenvolvimento e aplicação de um conjunto de seis fichas de inspecção e diagnóstico, organizadas por elementos/componentes do edifício, a cerca de 500 edifícios antigos do Núcleo Urbano Antigo do Seixal, em Portugal. Os resultados são posteriormente tratados estatisticamente e utilizados na criação de uma base de dados incorporada numa ferramenta de gestão integrada num Sistema de Informação Geográfica (SIG) aplicável na gestão do edificado à escala urbana
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