1,246 research outputs found

    Digital logic simulator comparison in educational purpose

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    Abstract. This work is comparing browser-based and computer installed digital logic circuit simulators, which can be used in for learning digital logic. Theory section introduces basics of combinational and sequential logic.Digitaalipiirisimulaattorien vertailu opetuskäytössä. Tiivistelmä. Kandidaatin tutkielmassa verrataan Internet-selaimissa toimivia pohjaisia ja tietokoneelle valmiiksi asennettuja digitaalipiirien logiikkasimulaattoreita opetuskäytössä, huomioiden suorituskyky, helppokäyttöisyys ja eri ominaisuuksia logiikkapiirien kuvaamiseen. Teoriaosiossa esitellään kombinaatio-, sekä sekvenssilogiikan perusteita

    The Genome of the "Great Speciator" Provides Insights into Bird Diversification

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    Among birds, white-eyes (genus Zosterops) have diversified so extensively that Jared Diamond and Ernst Mayr referred to them as the “great speciator.” The Zosterops lineage exhibits some of the fastest rates of species diversification among vertebrates, and its members are the most prolific passerine island colonizers. We present a high-quality genome assembly for the silvereye (Zosterops lateralis), a white-eye species consisting of several subspecies distributed across multiple islands. We investigate the genetic basis of rapid diversification in white-eyes by conducting genomic analyses at varying taxonomic levels. First, we compare the silvereye genome with those of birds from different families and searched for genomic features that may be unique to Zosterops. Second, we compare the genomes of different species of white-eyes from Lifou island (South Pacific), using whole genome resequencing and restriction site associated DNA. Third, we contrast the genomes of two subspecies of silvereye that differ in plumage color. In accordance with theory, we show that white-eyes have high rates of substitutions, gene duplication, and positive selection relative to other birds. Below genus level, we find that genomic differentiation accumulates rapidly and reveals contrasting demographic histories between sympatric species on Lifou, indicative of past interspecific interactions. Finally, we highlight genes possibly involved in color polymorphism between the subspecies of silvereye. By providing the first whole-genome sequence resources for white-eyes and by conducting analyses at different taxonomic levels, we provide genomic evidence underpinning this extraordinary bird radiation

    Multi-frequency VLBA study of the blazar S5 0716+714 during the active state in 2004: I. Inner jet kinematics

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    We observed the blazar \object{0716+714} with the VLBA during its active state in 2003-2004. In this paper we discuss multi-frequency analysis of the inner jet (first 1 mas) kinematics. The unprecedentedly dense time sampling allows us to trace jet components without misidentification and to calculate the component speeds with good accuracy. In the smooth superluminal jet we were able to identify and track three components over time moving outwards with relatively high apparent superluminal speeds (8.5-19.4 cc), which contradicts the hypothesis of a stationary oscillating jet in this source. Component ejections occur at a relatively high rate (once in two months), and they are accompanied by mm-continuum outbursts. Superluminal jet components move along wiggling trajectories, which is an indication of actual helical motion. Fast proper motion and rapid decay of the components suggest that this source should be observed with the VLBI at a rate of at least once in one or two months in order to trace superluminal jet components without confusion.Comment: 4 pages, 3 figures, Astronomy & Astrophysics Letter, language corrections adde

    Same-sex sociosexual behaviour is widespread and heritable in male rhesus macaques

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    Numerous reports have documented the occurrence of same-sex sociosexual behaviour (SSB) across animal species. However, the distribution of the behaviour within a species is needed to test the theories describing its evolution and maintenance, in particular whether the behaviour is heritable and can therefore evolve by natural selection. Here, we collected detailed observations across three years of social and mounting behaviour of 236 male semi-wild rhesus macaques, which we combined with a pedigree dating back to 1938, to show that SSB was both repeatable (19.35%) and heritable (6.4%). Demographic factors (age and group structure) explained SSB variation only marginally. Furthermore, we found a positive genetic correlation between same-sex mounter and mountee activities, indicating a common basis to different forms of SSB. Finally, we found no evidence of fitness costs to SSB, but show instead that the behaviour mediated coalitionary partnerships that have been linked with improved reproductive success. Together, our results demonstrate that SSB is frequent in rhesus macaques, can evolve, and is not costly, indicating that SSB may be a common feature of primate reproductive ecology

    Virtual Teamwork Environment -A Web-Based Conical Administration Framework for MNC

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    Because today\u27s commerce is information intensive and requires sophisticated computer support, it is difficult for the traditional corporations working individually to adapt the new environment to utilize information and build multinational teams effectively and efficiently. The need for global competitiveness makes multinational corporation (MNC) shift to a new team style: virtual teams, which are groups of individuals collaborating in the execution of a specific project while located at multiple individual sites or multiple group sites [1]. The environment of a virtual team is a cyberspace in which virtual project groups communicate mutually. In this paper, we focus on the functionality and structure of this highly abstract system. The groupware available for the teamwork collaboration is briefly introduced. A web-based teamwork environment served for MNC is thenpresented. We present a conical management architecture combined with a network topology: a peers and client/server mode instead of the traditional client/server and pure peers mode. It provides an orderly teamwork environment to replace the crowed and chaos-like teamwork space used currently. A design and implementation of the framework is finally described based on Sun Microsystems\u27 Java languag

    The Parsec-scale Structure, Kinematics, and Polarization of Radio-Loud Narrow-Line Seyfert 1 Galaxies

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    Several narrow-line Seyfert 1 galaxies (NLS1s) have now been detected in gamma rays, providing firm evidence that at least some of this class of active galactic nuclei (AGN) produce relativistic jets. The presence of jets in NLS1s is surprising, as these sources are typified by comparatively small black hole masses and near- or super-Eddington accretion rates. This challenges the current understanding of the conditions necessary for jet production. Comparing the properties of the jets in NLS1s with those in more familiar jetted systems is thus essential to improve jet production models. We present early results from our campaign to monitor the kinematics and polarization of the parsec-scale jets in a sample of 15 NLS1s through multifrequency observations with the Very Long Baseline Array. These observations are complemented by fast-cadence 15 GHz monitoring with the Owens Valley Radio Observatory 40m telescope and optical spectroscopic monitoring with with the 2m class telescope at the Guillermo Haro Astrophysics Observatory in Cananea, Mexico.Comment: 4 pages, 1 figure. To appear in the Proceedings of the IAU Symposium No. 313: "Extragalactic jets from every angle," Galapagos, Ecuador, 15-19 September 2014, F. Massaro, C. C. Cheung, E. Lopez, and A. Siemiginowska (Eds.), Cambridge University Pres
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