112,889 research outputs found

    The Coarse Geometry of Merger Trees in \Lambda CDM

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    We introduce the contour process to describe the geometrical properties of merger trees. The contour process produces a one-dimensional object, the contour walk, which is a translation of the merger tree. We portray the contour walk through its length and action. The length is proportional to to the number of progenitors in the tree, and the action can be interpreted as a proxy of the mean length of a branch in a merger tree. We obtain the contour walk for merger trees extracted from the public database of the Millennium Run and also for merger trees constructed with a public Monte-Carlo code which implements a Markovian algorithm. The trees correspond to halos of final masses between 10^{11} h^{-1} M_sol and 10^{14} h^{-1} M_sol. We study how the length and action of the walks evolve with the mass of the final halo. In all the cases, except for the action measured from Markovian trees, we find a transitional scale around 3 \times 10^{12} h^{-1} M_sol. As a general trend the length and action measured from the Markovian trees show a large scatter in comparison with the case of the Millennium Run trees.Comment: 7 pages, 5 figures, submitted to MNRA

    Intellectual Property Research: From the Dustiest Law Book to the Most Far off Database

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    This issue of IDEA introduces a regular series of articles on intellectual property research tools and strategies based on my experience for over a decade as Intellectual Property Librarian and Research Professor at Franklin Pierce Law Center. Pierce Law is consistently ranked among the top law schools training IP professionals. I have taught IP legal research, patent, trademark and copyright searching to hundreds of students and IP professionals in Pierce Law Graduate Programs. I have tackled hundreds of reference and research questions as well as working on countless projects requiring IP information. So I have been faced with challenges and changes common to consumers of IP information. What are the types of data IP researchers seek? What are the options for access to such data? How do we evaluate the access points? What is the value added to our information access choices? The mission of this series is to present tools and strategies and answers some of these consumer questions within evaluative frameworks appropriate to the tools under consideration. Each information acquisition choice is made on a moment-by-moment basis subject to the press of business. Choices are made by the totality of the circumstances. Pressures and factors such as time and money often drive information consumption and will be acknowledged and addressed in the series. Despite the intense growth of IP as a legal specialty, the widespread focus on IP in other disciplines outside the law and the increasing use of non-legal data such as patent statistical indicators, little has been written on IP research. There are no dedicated treatises or periodicals on IP legal research. There are no comprehensive treatises on patent, trademark or copyright searching. The intent of this series is not scholarship and footnotes. The intent is to provide some helpful tools and strategies to those performing IP research on the spectrum from law to facts. So, the phrase IP research in this introduction, unless otherwise specified, refers to the acquisition all types of IP information by the full range of consumers

    The Millennium Run Observatory: First Light

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    Simulations of galaxy evolution aim to capture our current understanding as well as to make predictions for testing by future experiments. Simulations and observations are often compared in an indirect fashion: physical quantities are estimated from the data and compared to models. However, many applications can benefit from a more direct approach, where the observing process is also simulated and the models are seen fully from the observer's perspective. To facilitate this, we have developed the Millennium Run Observatory (MRObs), a theoretical virtual observatory which uses virtual telescopes to `observe' semi-analytic galaxy formation models based on the suite of Millennium Run dark matter simulations. The MRObs produces data that can be processed and analyzed using the standard software packages developed for real observations. At present, we produce images in forty filters from the rest-frame UV to IR for two stellar population synthesis models, three different models of IGM absorption, and two cosmologies (WMAP1/7). Galaxy distributions for a large number of mock lightcones can be `observed' using models of major ground- and space-based telescopes. The data include lightcone catalogues linked to structural properties of galaxies, pre-observation model images, mock telescope images, and Source Extractor products that can all be traced back to the higher level dark matter, semi-analytic galaxy, and lightcone catalogues available in the Millennium database. Here, we describe our methods and announce a first public release of simulated surveys (e.g., SDSS, CFHT-LS, GOODS, GOODS/ERS, CANDELS, and HUDF). The MRObs browser, an online tool, further facilitates exploration of the simulated data. We demonstrate the benefits of a direct approach through a number of example applications (galaxy number counts in CANDELS, clusters, morphologies, and dropout selections).Comment: MNRAS, in press. Millennium Run Observatory data products, online tools, and more available through http://galformod.mpa-garching.mpg.de/mrobs

    The MultiDark Database: Release of the Bolshoi and MultiDark Cosmological Simulations

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    We present the online MultiDark Database -- a Virtual Observatory-oriented, relational database for hosting various cosmological simulations. The data is accessible via an SQL (Structured Query Language) query interface, which also allows users to directly pose scientific questions, as shown in a number of examples in this paper. Further examples for the usage of the database are given in its extensive online documentation (www.multidark.org). The database is based on the same technology as the Millennium Database, a fact that will greatly facilitate the usage of both suites of cosmological simulations. The first release of the MultiDark Database hosts two 8.6 billion particle cosmological N-body simulations: the Bolshoi (250/h Mpc simulation box, 1/h kpc resolution) and MultiDark Run1 simulation (MDR1, or BigBolshoi, 1000/h Mpc simulation box, 7/h kpc resolution). The extraction methods for halos/subhalos from the raw simulation data, and how this data is structured in the database are explained in this paper. With the first data release, users get full access to halo/subhalo catalogs, various profiles of the halos at redshifts z=0-15, and raw dark matter data for one time-step of the Bolshoi and four time-steps of the MultiDark simulation. Later releases will also include galaxy mock catalogs and additional merging trees for both simulations as well as new large volume simulations with high resolution. This project is further proof of the viability to store and present complex data using relational database technology. We encourage other simulators to publish their results in a similar manner.Comment: 28 pages, 9 figures, submitted to New Astronom

    The emergence of commercial genomics: analysis of the rise of a biotechnology subsector during the Human Genome Project, 1990 to 2004.

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    BackgroundDevelopment of the commercial genomics sector within the biotechnology industry relied heavily on the scientific commons, public funding, and technology transfer between academic and industrial research. This study tracks financial and intellectual property data on genomics firms from 1990 through 2004, thus following these firms as they emerged in the era of the Human Genome Project and through the 2000 to 2001 market bubble.MethodsA database was created based on an early survey of genomics firms, which was expanded using three web-based biotechnology services, scientific journals, and biotechnology trade and technical publications. Financial data for publicly traded firms was collected through the use of four databases specializing in firm financials. Patent searches were conducted using firm names in the US Patent and Trademark Office website search engine and the DNA Patent Database.ResultsA biotechnology subsector of genomics firms emerged in parallel to the publicly funded Human Genome Project. Trends among top firms show that hiring, capital improvement, and research and development expenditures continued to grow after a 2000 to 2001 bubble. The majority of firms are small businesses with great diversity in type of research and development, products, and services provided. Over half the public firms holding patents have the majority of their intellectual property portfolio in DNA-based patents.ConclusionsThese data allow estimates of investment, research and development expenditures, and jobs that paralleled the rise of genomics as a sector within biotechnology between 1990 and 2004
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