31,629 research outputs found
Meiotic behavior of the Brazilian table grape cultivar Rubi (Vitis vinifera) with a high proportion of seedless berries
Meiotic behavior, pollen fertility and germination of the Brazilian table grape cv, Rubi (Vitis vinifera) were investigated; this cultivar produced different numbers of seedless berries when cultivated at two different sites: At site A vines produced a high proportion of seedless berries while at site B vines produced berries with a normal number of seeds. Cytological analysis of inflorescences collected from the two sites showed some meiotic abnormalities, the most common being related to chromosomal segregation and telophase micronuclei formation leading to microcyte formation in the tetrads, Cytoplasmic channels, bridges and tripolar spindles were also observed in some microsporocytes, Pollen fertility was high at both sites, approximately 96 % at site A and 98 % at site B, The rate of pollen germination was lower at site A than at site B, suggesting that the absence of seed formation is related to pollen germination rate.
Will drones have a role in building construction?
This paper aims to explore the possibilities that robotic technologies, namely robotic arms and drones, bring to architecture and to the construction sector. The developed research was based in an extensive literature review, in the conceptualization of three experiments to be done with drones and in interviews with Fabio Gramazio, Tobias Bonwetsch (ETH Zurich) and José Pedro Sousa (FAUP). The paper starts by presenting a brief story of the introduction of robotic technologies in other industries and identifies the robotic technologies that are presently use, mainly in research, to assemble construction elements – drones and robotic arms. We then analyze the few case studies of construction performed with drones and robotic arms. Three experiments are idealized next in order to clarify the main difficulties of each action of construction performed by a robot. The advances in robotic construction are visible and growing every year. According to the experts robotic construction will be introduced in the construction industry in a hybrid way, where man and machine collaborate and not as total substitution of human labor.info:eu-repo/semantics/acceptedVersio
Adubação fosfatada e regime de uso de uma caatinga raleada. 2. Produção do estrato herbáceo.
A pesquisa objetivou determinar os efeitos da adubação fosfatada, do regime de uso e do sistema de manejo sobre a produção da vegetação herbácea da caatinga raleada. 0 experimento foi um fatorial de 23x3, (dois nĂveis de adubação, dois regime de uso, dois sistemas de manejo e trĂŞs anos), em parcelas subdivididas, com distribuição em blocos ao acaso, com tres repetições. Os resultados indicaram que a adubação aumentou a produtividade do estrato herbáceo, desde que associada ao uso da pastagem ao meio e ao fim do perĂodo chuvoso. 0 corte nao afetou a produtividade das gramĂneas e das ervas anuais, enquanto que, o pastejo com ovinos favoreceu a produção das ervas. As flutuayoes anuais da produção de fitomassa foram elevadas, dependeram, provavelmente, das precipitações pluviais, e apontam a necessidade de prazos prolongados para a confiabilidade dos resultados da pesquisa nesta área de conhecimento
Light composite Higgs boson from the normalized Bethe-Salpeter equation
Scalar composite boson masses have been computed in QCD and Technicolor
theories with the help of the homogeneous Bethe-Salpeter equation (BSE),
resulting in a scalar mass that is twice the dynamically generated fermion or
technifermion mass (). We show that in the case of walking (or
quasi-conformal) technicolor theories, where the behavior with the
momenta may be quite different from the one predicted by the standard operator
product expansion, this result is incomplete and we must consider the effect of
the normalization condition of the BSE to determine the scalar masses. We
compute the composite Higgs boson mass for several groups with technifermions
in the fundamental and higher dimensional representations and comment about the
experimental constraints on these theories, which indicate that models based on
walking theories with fermions in the fundamental representation may, within
the limitations of our approach, have masses quite near the actual direct
exclusion limit.Comment: 9 pages, 4 figures, minor corrections, to appear in Physical Review
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Beauty in efficiency: An experimental enquiry into the principle of maximum effect for minimum means
Theory and discourse suggest that the aesthetic appreciation of a wide range of artifacts—including works of art and consumer products—is partially governed by the principle of maximum effect for minimum means. We conducted two studies to find experimental evidence of this principle in the context of product design. In Study 1, we tested the hypothesis that the aesthetic appreciation of a product would be positively affected by the perception of the product as the minimum means achieving the maximum effect. Encouraged by the results of this study, we conducted Study 2 to test again the principle of maximum effect for minimum means using a more controlled experimental design. Our findings provide support for our hypothesis, indicating that the aesthetic appreciation of a product depends, to some extent, on the perception that the product achieves more than other products from its category by making an efficient use of resources.This research is part of Project UMA, which is supported by the MAGW VICI grant number 453-10-004 awarded to Paul Hekkert by The Netherlands Organization for Scientific Research.This is the author accepted manuscript. The final version is available from SAGE via https://doi.org/10.1177/027623741663848
Maximum effect for minimum means: The aesthetics of efficiency
The aesthetic judgment of an artifact is usually interpreted as an assessment of the artifact's sensory properties. But an artifact can also be appreciated, and still aesthetically, for the way it fulfills its purpose. Existing design theory does not provide the concepts required for describing this aspect of aesthetic appreciation and so cannot fully explain what people mean when they say a product is beautiful. In this paper, we develop an understanding of the aesthetic judgment based on the principle of maximum effect for minimum means. We explain how a means–effect relationship can be established between a product and its purpose or effect, and how the product and the effect can be perceived to be minimal and maximal. We also explain how the appreciation of this relationship depends on a set of assumed alternatives for both the product or means and the effect. Finally, we provide some directions for future research into design aesthetics. This research is part of Project UMA (www.project-uma.com), which is supported by the MAGW VICI grant number 453-10-004, awarded to Paul Hekkert by The Netherlands Organization for Scientific Research.This is the final version of the article. It first appeared from MIT Press via http://dx.doi.org/10.1162/DESI_a_0036
How people’s appreciation of products is affected by their knowledge of the designers’ intentions
Products result from processes that are guided by designers’ intentions for what the products should be, what they should be like and what they should do. People might infer these intentions more or less accurately from the products’ form, or they might learn about them from a variety of sources such as advertisements and other marketing materials. Whether inferred or learned, knowledge of design intentions might influence the way in which people regard and appreciate products. Despite this possible influence, design research has not empirically addressed the questions of whether intention knowledge affects product appreciation and, if so, how. We investigated these questions by conducting two studies using a mixed-methods approach. Study 1 provided experimental evidence that intention knowledge has an effect on product appreciation. Study 2 explained this effect with interview data showing that intention knowledge affects product appreciation in three ways: it influences the perception of the product, enables an evaluation of the intention and also an evaluation of the product as a means to fulfill the intention. These findings are relevant to design research and practice in providing the grounds for a deeper understanding of the role that intention knowledge plays in product appreciation.This research is part of Project UMA (www.project-uma.com), which is supported by the MAGW VICI grant number 453-10-004, awarded to Paul Hekkert by The Netherlands Organization for Scientific Research.This is the final version of the article. It first appeared from Chinese Institute of Design via http://www.ijdesign.org/ojs/index.php/IJDesign/article/view/196
Spin-1 Particles with Light-Front Approach
For the vector sector, i.e, mesons with spin-1, the electromagnetic form
factors and anothers observables are calculated with the light-front approach.
However, the light-front quantum field theory have some problems, for example,
the rotational symmetry breaking. We solve that problem added the zero modes
contribuition to the matrix elements of the electromagnetic current, besides
the valence contribuition. We found that among the four independent matrix
elements of the plus component in the light-front helicity basis only the one carries zero mode contributions.Comment: 5 pages. 3 Figures, use latex and EPJ styl
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