1,592 research outputs found

    „Wissensraum Architektur“– A Constructivist Model of Learning for Architectural Education at Anhalt University of Applied Sciences

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    The study of architecture is by nature highly interdisciplinary. Design, structure, technology, ecology and economics must all be considered in the process of planning and building. Therefore it is important to encourage an integrated approach in terms of education and to create a interdisciplinary network of learning contents. Wissensraum Architektur is a contribution to this idea. Wissensraum Architektur is an internet-based system for teaching and learning at the Department of Architecture and Civil Engineering at Anhalt University of Applied Sciences in Dessau. The basis of Wissensraum is a pool of media elements and multimedia based components to which authors from different fields contribute. The authoring system allows instructors to create, by simple means, digital learning modules. Due to the modular structure, modular elements and sequences in varying relations and by different authors can be reused and restructured. A knowledge map visualizes relationships among the different learning content. In this way, a virtual campus in Dessau is created step by step. The didactical concept of Wissensraum supports Constructivist models of learning. Users can use the database for research and can create their own way of learning concerning particular themes. The availability via Internet makes it possible to work from any location at any time

    Measuring Galaxy Environments with Deep Redshift Surveys

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    We study the applicability of several galaxy environment measures (n^th-nearest-neighbor distance, counts in an aperture, and Voronoi volume) within deep redshift surveys. Mock galaxy catalogs are employed to mimic representative photometric and spectroscopic surveys at high redshift (z ~ 1). We investigate the effects of survey edges, redshift precision, redshift-space distortions, and target selection upon each environment measure. We find that even optimistic photometric redshift errors (\sigma_z = 0.02) smear out the line-of-sight galaxy distribution irretrievably on small scales; this significantly limits the application of photometric redshift surveys to environment studies. Edges and holes in a survey field dramatically affect the estimation of environment, with the impact of edge effects depending upon the adopted environment measure. These edge effects considerably limit the usefulness of smaller survey fields (e.g. the GOODS fields) for studies of galaxy environment. In even the poorest groups and clusters, redshift-space distortions limit the effectiveness of each environment statistic; measuring density in projection (e.g. using counts in a cylindrical aperture or a projected n^th-nearest-neighbor distance measure) significantly improves the accuracy of measures in such over-dense environments. For the DEEP2 Galaxy Redshift Survey, we conclude that among the environment estimators tested the projected n^th-nearest-neighbor distance measure provides the most accurate estimate of local galaxy density over a continuous and broad range of scales.Comment: 17 pages including 16 figures, accepted to Ap

    The Cepheid distance to the maser-host galaxy NGC 4258: Studying systematics with the Large Binocular Telescope

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    We identify and phase a sample of 81 Cepheids in the maser-host galaxy NGC 4258 using the Large Binocular Telescope (LBT), and obtain calibrated mean magnitudes in up to 4 filters for a subset of 43 Cepheids using archival HST data. We employ 3 models to study the systematic effects of extinction, the assumed extinction law, and metallicity on the Cepheid distance to NGC 4258. We find a correction to the Cepheid colors consistent with a grayer extinction law in NGC 4258 compared to the Milky Way (RV=4.9R_V =4.9), although we believe this is indicative of other systematic effects. If we combine our Cepheid sample with previously known Cepheids, we find a significant metallicity adjustment to the distance modulus of γ1=−0.61±0.21\gamma_1 = -0.61 \pm 0.21 mag/dex, for the Zaritsky et al. (1994) metallicity scale, as well as a weak trend of Cepheid colors with metallicity. Conclusions about the absolute effect of metallicity on Cepheid mean magnitudes appear to be limited by the available data on the metallicity gradient in NGC 4258, but our Cepheid data require at least some metallicity adjustment to make the Cepheid distance consistent with independent distances to the LMC and NGC 4258. From our ensemble of models and the geometric maser distance of NGC 4258 (μN4258=29.40±0.06\mu_{N4258} = 29.40 \pm 0.06 mag), we estimate μLMC=18.57±0.14\mu_{LMC} = 18.57 \pm 0.14 mag (51.82±3.2351.82 \pm 3.23 kpc).Comment: Accepted for publication in MNRAS. 28 pages, 13 figures, 11 tables. A brief video summarizing the key results of this paper can be found at http://youtu.be/ICTTNyxZ89

    A Powerful New Quantitative Genetics Platform, Combining Caenorhabditis elegans High-Throughput Fitness Assays with a Large Collection of Recombinant Strains.

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    The genetic variants underlying complex traits are often elusive even in powerful model organisms such as Caenorhabditis elegans with controlled genetic backgrounds and environmental conditions. Two major contributing factors are: (1) the lack of statistical power from measuring the phenotypes of small numbers of individuals, and (2) the use of phenotyping platforms that do not scale to hundreds of individuals and are prone to noisy measurements. Here, we generated a new resource of 359 recombinant inbred strains that augments the existing C. elegans N2xCB4856 recombinant inbred advanced intercross line population. This new strain collection removes variation in the neuropeptide receptor gene npr-1, known to have large physiological and behavioral effects on C. elegans and mitigates the hybrid strain incompatibility caused by zeel-1 and peel-1, allowing for identification of quantitative trait loci that otherwise would have been masked by those effects. Additionally, we optimized highly scalable and accurate high-throughput assays of fecundity and body size using the COPAS BIOSORT large particle nematode sorter. Using these assays, we identified quantitative trait loci involved in fecundity and growth under normal growth conditions and after exposure to the herbicide paraquat, including independent genetic loci that regulate different stages of larval growth. Our results offer a powerful platform for the discovery of the genetic variants that control differences in responses to drugs, other aqueous compounds, bacterial foods, and pathogenic stresses

    The search for failed supernovae with the Large Binocular Telescope: constraints from 7 yr of data

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    We report updated results for the first 7 yr of our programme to monitor 27 galaxies within 10 Mpc using the Large Binocular Telescope to search for failed supernovae (SNe) – core collapses of massive stars that form black holes without luminous SNe. In the new data, we identify no new compelling candidates and confirm the existing candidate. Given the six successful core-collapse SNe in the sample and one likely failed SN, the implied fraction of core collapses that result in failed SNe is f=0.14^(+0.33)_(−0.10) at 90 per cent confidence. If the current candidate is a failed SN, the fraction of failed SN naturally explains the missing high-mass red supergiants SN progenitors and the black hole mass function. If the current candidate is ultimately rejected, the data imply a 90 per cent confidence upper limit on the failed SN fraction of f < 0.35
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