1,585 research outputs found
Architekturströmungen der Gegenwart in der Bundesrepublik Deutschland am Beispiel der Bundeshauptstadt Bonn
Wissenschaftliches Kolloquium vom 24. bis 26. Juni 1986 in Weimar an der Hochschule für Architektur und Bauwesen zum Thema: 'Der wissenschaftlich-technische Fortschritt und die sozial-kulturellen Funktionen von Architektur und industrieller Formgestaltung in unserer Epoche
Measuring dark matter by modeling interacting galaxies
The dark matter content of galaxies is usually determined from galaxies in
dynamical equilibrium, mainly from rotationally supported galactic components.
Such determinations restrict measurements to special regions in galaxies, e.g.
the galactic plane(s), whereas other regions are not probed at all. Interacting
galaxies offer an alternative, because extended tidal tails often probe outer
or off-plane regions of galaxies. However, these systems are neither in
dynamical equilibrium nor simple, because they are composed of two or more
galaxies, by this increasing the associated parameter space.We present our
genetic algorithm based modeling tool which allows to investigate the extended
parameter space of interacting galaxies. From these studies, we derive the
dynamical history of (well observed) galaxies. Among other parameters we
constrain the dark matter content of the involved galaxies. We demonstrate the
applicability of this strategy with examples ranging from stellar streams
around theMilkyWay to extended tidal tails, from proto-typical binary galaxies
(like M51 or the Antennae system) to small group of galaxies.Comment: 4 pages, 3 figures, Conf.: Hunting for the dark, Malta 200
Zum Wohnungsbau der 50er Jahre in der Bundesrepublik Deutschland
Wissenschaftliches Kolloquium vom 5. bis 7. Juli 1983 in Weimar an der Hochschule für Architektur und Bauwesen zum Thema: 'Das Bauhauserbe und die gegenwärtige Entwicklung der Architektur : zum 100. Geburtstag von Walter Gropius
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Industrial Freeform Generation of Microtools by Laser Micro Sintering
Precision tools with structural resolution reaching the 20 micrometer range can be generated
on an industrial scale by “laser micro sintering”. Components featuring aspect ratios above 12
and a roughness Ra down to 1.5 micrometers have already been produced from sub micrometer
grained metal powders. The components can be generated either firmly attached to a substrate or
fixed in an easily separable mode. If supporting structures are employed, undercuts up to 90° are
feasible, without, a process parameter dependent maximum angles of undercut below 90° are
obtained.
The process has been introduced into the market, labeled microSINTERING by
3D-Micromac AG.Mechanical Engineerin
Modeling and visualizing urban sprawl and carbon footprints in Phoenix metropolitan area
Urban planners are dealing with problems of urban sprawl and CO2 emissions. The multidimensional character of these phenomena requires new analysis and visualization tools that are unavailable in platforms like the Geographical Information Systems (GIS). This paper, first, presents an approach for measuring and monitoring urban sprawl and carbon footprints. Second, it offers a three-dimensional visualization method that takes into account the multi-dimensional nature of the data. The visualization of the data is based on an intuitive approach involving B-Splines and Bezier techniques to create three-dimensional surfaces. Finally the paper introduces an analysis tool for planners and decision makers to examine household carbon footprints in relation to their direct spatial neighborhood based on unstructured census data
Genome-Wide Analysis of leafbladeless1-Regulated and Phased Small RNAs Underscores the Importance of the TAS3 ta-siRNA Pathway to Maize Development
Maize leafbladeless1 (lbl1) encodes a key component in the trans-acting short-interfering RNA (ta-siRNA) biogenesis pathway. Correlated with a great diversity in ta-siRNAs and the targets they regulate, the phenotypes conditioned by mutants perturbing this small RNA pathway vary extensively across species. Mutations in lbl1 result in severe developmental defects, giving rise to plants with radial, abaxialized leaves. To investigate the basis for this phenotype, we compared the small RNA content between wild-type and lbl1 seedling apices. We show that LBL1 affects the accumulation of small RNAs in all major classes, and reveal unexpected crosstalk between ta-siRNA biogenesis and other small RNA pathways regulating transposons. Interestingly, in contrast to data from other plant species, we found no evidence for the existence of phased siRNAs generated via the one-hit model. Our analysis identified nine TAS loci, all belonging to the conserved TAS3 family. Information from RNA deep sequencing and PARE analyses identified the tasiR-ARFs as the major functional ta-siRNAs in the maize vegetative apex where they regulate expression of AUXIN RESPONSE FACTOR3 (ARF3) homologs. Plants expressing a tasiR-ARF insensitive arf3a transgene recapitulate the phenotype of lbl1, providing direct evidence that deregulation of ARF3 transcription factors underlies the developmental defects of maize ta-siRNA biogenesis mutants. The phenotypes of Arabidopsis and Medicago ta-siRNA mutants, while strikingly different, likewise result from misexpression of the tasiR-ARF target ARF3. Our data indicate that diversity in TAS pathways and their targets cannot fully account for the phenotypic differences conditioned by ta-siRNA biogenesis mutants across plant species. Instead, we propose that divergence in the gene networks downstream of the ARF3 transcription factors or the spatiotemporal pattern during leaf development in which these proteins act constitute key factors underlying the distinct contributions of the ta-siRNA pathway to development in maize, Arabidopsis, and possibly other plant species as well
Adjuvant effects of a sequence-engineered mRNA vaccine: translational profiling demonstrates similar human and murine innate response
Additional file 1: Fig. S1. Components and assembly of the PTE module for innate responses. (A) Top panel—in vivo monocytes continuously emigrate from the blood into peripheral tissues with a half-life in the blood of ~1 day. Bottom panel: In vitro generation of cytokine derived DCs from monocytes involves the addition of IL-4 and GM-CSF and culture for 7–11 days. (B) Schematic of the components of a MIMIC-PTE module. In the 3D PTE, differentiation occurs in hours to about 2 days triggered by migration into and out of (reverse migration) through the endothelium: a process reminiscent of the movement of cells from tissues into lymphatic vessels
Distribuição longitudinal de Chironomidae (Diptera) abaixo de uma barragem em um rio neotropical
The damming of a river causes dangerous consequences on structure of the environment downstream of the dam, modifying the sediment composition, which impose major adjustments in longitudinal distribution of benthic community. The construction of Engenheiro Sérgio Motta Dam in the Upper Paraná River has caused impacts on the aquatic communities, which are not yet fully known. This work aimed to provide more information about the effects of this impoundment on the structure of Chironomidae larvae assemblage. The analysis of data of physical and chemical variables in relation to biological data of 8 longitudinal sections in the Upper Paraná River showed that composition of Chironomidae larvae of stations near Engenheiro Sérgio Motta Dam differed of the other stations (farther of the Dam) The predominance of coarse sediments at stations upstream and finer sediments further downstream affected the choice of habitat by different morphotypes of Chironomidae and it caused a change in the structure of this assemblage in the longitudinal stretch.O barramento de um rio pode causar graves consequências sobre a natureza do ambiente, abaixo da barragem, modificando a composição do sedimento, as quais impõem importantes ajustes da distribuição longitudinal das comunidades bentônicas. A construção da Usina Hidrelétrica Engenheiro Sérgio Motta no alto rio Paraná, tem causado impactos em várias comunidades aquáticas, que ainda não são totalmente conhecidos. Este trabalho objetivou fornecer mais informações sobre os efeitos desse represamento na assembleia de Chironomidae. A análise das variáveis físicas e químicas em relação aos dados biológicos de oito transectos longitudinais no alto rio Paraná revelou que a composição das larvas de Chironomidae das estações mais próximas à barragem da Usina Engenheiro Sérgio Motta diferiu das demais (estações mais distantes). A predominância de sedimentos mais grosseiros nas estações a montante e sedimentos mais finos mais a jusante afetou a escolha de habitat pelos diferentes morfotipos de Chironomidae, que levou a alteração na estrutura desta assembleia ao longo do trecho amostrado.Fil: Pinha, G. D.. Universidade Estadual de Maringá. Programa de Pós-Graduação em Ecologia de Ambientes Aquáticos Continentais; Brasil.;Fil: Aviz, D.. Universidade Federal Do Pará; Brasil.;Fil: Lopes Filho, D. R.. Universidade Estadual de Maringá. Programa de Pós-Graduação em Ecologia de Ambientes Aquáticos Continentais; Brasil.;Fil: Petsch, D. K.. Universidade Estadual de Maringá. Programa de Pós-Graduação em Ecologia de Ambientes Aquáticos Continentais; Brasil.;Fil: Marchese Garello, Mercedes Rosa. Consejo Nacional de Investigaciones científicas y Técnicas. Centro Científico Tecnológico CONICET- Santa Fe. Instituto Nacional de Limnologia (i); Argentina;Fil: Takeda, A. M.. Universidade Estadual de Maringá; Brasil.
Simulations of the grand design galaxy M51: a case study for analysing tidally induced spiral structure
We present hydrodynamical models of the grand design spiral M51 (NGC 5194),
and its interaction with its companion NGC 5195. Despite the simplicity of our
models, our simulations capture the present day spiral structure of M51
remarkably well, and even reproduce details such as a kink along one spiral
arm, and spiral arm bifurcations. We investigate the offset between the stellar
and gaseous spiral arms, and find at most times (including the present day)
there is no offset between the stars and gas to within our error bars. We also
compare our simulations with recent observational analysis of M51. We compute
the pattern speed versus radius, and like the observations, find no single
global pattern speed. We also show that the spiral arms cannot be fitted well
by logarithmic spirals. We interpret these findings as evidence that M51 does
not exhibit a quasi-steady density wave, as would be predicted by density wave
theory. The internal structure of M51 derives from the complicated and
dynamical interaction with its companion, resulting in spiral arms showing
considerable structure in the form of short-lived kinks and bifurcations.
Rather than trying to model such galaxies in terms of global spiral modes with
fixed pattern speeds, it is more realistic to start from a picture in which the
spiral arms, while not being simple material arms, are the result of tidally
induced kinematic density `waves' or density patterns, which wind up slowly
over time.Comment: 23 pages, 20 figures, accepted for publication in MNRA
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