784 research outputs found

    Najas flexilis (Hydrocharitaceae) in Alaska : a reassessment

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    Author Posting. © New England Botanical Club, 2015. This article is posted here by permission of New England Botanical Club for personal use, not for redistribution. The definitive version was published in Rhorora 117 (2015): 354-370, doi:10.3119/15-03.Fifteen Najas flexilis collections were made in Alaska during the summer of 2012, with 13 of the stations representing either new or formerly undocumented localities for this imperiled Alaskan species. These field collections characterize the Alaskan habitats of N. flexilis as shallow water sites (<1.5 m) with sand-dominated substrates (71% of sites) and have documented an additional 28 species associates (a 300% increase). However, the additional collections have not extended the elevational, latitudinal, or longitudinal extent of N. flexilis from the limits indicated by previous Alaskan collections. Najas flexilis remains rare in Alaska as evidenced by a low specimen recovery rate (10%) from potentially suitable sites, and a total of only 12 geographically distinct localities known across the entire state. The new collections have furnished valuable study material for morphological and genetic analyses, which have confirmed the identity of Alaskan populations as N. flexilis, rather than N. canadensis, a recently identified, cryptic, allotetraploid derivative. A synthesis of information indicates that N. flexilis is indigenous to Alaska, where it originated via past (versus recent) migrations from other North American rather than Old World populations.Portions of this work were funded by National Science Foundation grant DEB-0841658 to D.H.L

    Development of a cost-effective and flexible vibration DAQ system for long-term continuous structural health monitoring

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    In the structural health monitoring (SHM) field, long-term continuous vibration-based monitoring is becoming increasingly popular as this could keep track of the health status of structures during their service lives. However, implementing such a system is not always feasible due to on-going conflicts between budget constraints and the need of sophisticated systems to monitor real-world structures under their demanding in-service conditions. To address this problem, this paper presents a comprehensive development of a cost-effective and flexible vibration DAQ system for long-term continuous SHM of a newly constructed institutional complex with a special focus on the main building. First, selections of sensor type and sensor positions are scrutinized to overcome adversities such as low-frequency and low-level vibration measurements. In order to economically tackle the sparse measurement problem, a cost-optimized Ethernet-based peripheral DAQ model is first adopted to form the system skeleton. A combination of a high-resolution timing coordination method based on the TCP/IP command communication medium and a periodic system resynchronization strategy is then proposed to synchronize data from multiple distributed DAQ units. The results of both experimental evaluations and experimental-numerical verifications show that the proposed DAQ system in general and the data synchronization solution in particular work well and they can provide a promising cost-effective and flexible alternative for use in real-world SHM projects. Finally, the paper demonstrates simple but effective ways to make use of the developed monitoring system for long-term continuous structural health evaluation as well as to use the instrumented building herein as a multi-purpose benchmark structure for studying not only practical SHM problems but also synchronization related issues

    The Prevalence and Influence of the Combination of Humor and Violence in Super Bowl Commercials

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    The growing concern over violence in the media has led to vast amounts of research examining the effects of violent media on viewers. An important subset of this research looks at how humor affects this relationship. While research has considered this subset in television programming, almost no research has explored this in the context of advertising. This paper builds on the little research that exists by examining the effects of combining humor and violence, as well as the theoretical approaches that underlie these effects. A content analysis is conducted to identify the prevalence of violence, humor, and the combination of these elements in a longitudinal sample of Super Bowl commercials (2005, 2007, and 2009). Further, we investigate the relationship between the joint occurrence of humor and violence in ads and ad popularity. We conclude that violent acts are rampant in these commercials and that many acts are camouflaged by the simultaneous presence of humor, especially in the most popular ads

    Measurement of the cross-section and charge asymmetry of WW bosons produced in proton-proton collisions at s=8\sqrt{s}=8 TeV with the ATLAS detector

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    This paper presents measurements of the W+μ+νW^+ \rightarrow \mu^+\nu and WμνW^- \rightarrow \mu^-\nu cross-sections and the associated charge asymmetry as a function of the absolute pseudorapidity of the decay muon. The data were collected in proton--proton collisions at a centre-of-mass energy of 8 TeV with the ATLAS experiment at the LHC and correspond to a total integrated luminosity of 20.2~\mbox{fb^{-1}}. The precision of the cross-section measurements varies between 0.8% to 1.5% as a function of the pseudorapidity, excluding the 1.9% uncertainty on the integrated luminosity. The charge asymmetry is measured with an uncertainty between 0.002 and 0.003. The results are compared with predictions based on next-to-next-to-leading-order calculations with various parton distribution functions and have the sensitivity to discriminate between them.Comment: 38 pages in total, author list starting page 22, 5 figures, 4 tables, submitted to EPJC. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2017-13

    Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at √ s = 8 TeV with the ATLAS detector

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    Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fb−1 of √ s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente

    Search for chargino-neutralino production with mass splittings near the electroweak scale in three-lepton final states in √s=13 TeV pp collisions with the ATLAS detector

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    A search for supersymmetry through the pair production of electroweakinos with mass splittings near the electroweak scale and decaying via on-shell W and Z bosons is presented for a three-lepton final state. The analyzed proton-proton collision data taken at a center-of-mass energy of √s=13  TeV were collected between 2015 and 2018 by the ATLAS experiment at the Large Hadron Collider, corresponding to an integrated luminosity of 139  fb−1. A search, emulating the recursive jigsaw reconstruction technique with easily reproducible laboratory-frame variables, is performed. The two excesses observed in the 2015–2016 data recursive jigsaw analysis in the low-mass three-lepton phase space are reproduced. Results with the full data set are in agreement with the Standard Model expectations. They are interpreted to set exclusion limits at the 95% confidence level on simplified models of chargino-neutralino pair production for masses up to 345 GeV

    Bureaucratization in Public Research Institutions

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    The purpose of this paper is to analyse the nature of bureaucratization within public research bodies and its relationship to scientific performance, focusing on an Italian case-study. The main finding is that the bureaucratization of the research sector has two dimensions: public research labs have academic bureaucratization since researchers spend an increasing part of their time in administrative matters (i.e., preparing grant applications, managing grants/projects, and so on); whereas universities mainly have administrative bureaucratization generated by the increase over time of administrative staff in comparison with researchers and faculty. In addition, I show that research units with higher bureaucratization have lower scientific performance

    Healing through language: Positive Physical Health Effects of Indigenous Language Use

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    This article summarizes existing work that indicates language maintenance and revitalization efforts result in health-related benefits for Native Americans and other indigenous populations. Although forced loss of ancestral language has been a feature of life in most indigenous communities since the first contact with Europeans, the pace of loss has accelerated in the past 50 years. Among the many hardships such communities face, an especially troubling one is lowered health status. There are indications, however, that language maintenance and revitalization efforts have positive effects on physical and communal health among indigenous populations. The types of language programs currently in place are outlined along with a variety of studies that will measure health improvement outcomes correlated with language revitalization efforts. Such evidence justifies increased support for language revitalization in order to improve health
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