509 research outputs found

    Cascading effects of a highly specialized beech-aphid–fungus interaction on forest regeneration

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    Specialist herbivores are thought to often enhance or maintain plant diversity within ecosystems, because they prevent their host species from becoming competitively dominant. In contrast, specialist herbivores are not generally expected to have negative impacts on non-hosts. However, we describe a cascade of indirect interactions whereby a specialist sooty mold (Scorias spongiosa) colonizes the honeydew from a specialist beech aphid (Grylloprociphilus imbricator), ultimately decreasing the survival of seedlings beneath American beech trees (Fagus grandifolia). A common garden experiment indicated that this mortality resulted from moldy honeydew impairing leaf function rather than from chemical or microbial changes to the soil. In addition, aphids consistently and repeatedly colonized the same large beech trees, suggesting that seedling-depauperate islands may form beneath these trees. Thus this highly specialized three-way beech-aphid–fungus interaction has the potential to negatively impact local forest regeneration via a cascade of indirect effects

    Allocating the Burdens of Climate Action: Consumption-Based Carbon Accounting and the Polluter-Pays Principle

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    Action must be taken to combat climate change. Yet, how the costs of climate action should be allocated among states remains a question. One popular answer—the polluter-pays principle (PPP)—stipulates that those responsible for causing the problem should pay to address it. While intuitively plausible, the PPP has been subjected to withering criticism in recent years. It is timely, following the Paris Agreement, to develop a new version: one that does not focus on historical production-based emissions but rather allocates climate burdens in proportion to each state’s annual consumption-based emissions. This change in carbon accounting results in a fairer and more environmentally effective principle for distributing climate duties

    Radio Astronomy

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    Contains research objectives and summary of research.U. S. Air Force - Electronic Systems Division (Contract F19628-73-C-0196)National Science Foundation (Grant 40484X)Joint Services Electronics Program (Contract DAAB07-71-C-0300)National Institutes of Health (Grant 1 RO1 GM20370-01)U. S. Air Force - Air Force Systems Command (Contract F33615-72-C-2129)California Institute of Technology (Contract 952568)National Aeronautics and Space Administration (Contract NAS1 -10693)National Science Foundation (Grant GP-40485X

    Viperin is an important host restriction factor in control of Zika virus infection

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    Published online 30 June 2017Zika virus (ZIKV) infection has emerged as a global health threat and infection of pregnant women causes intrauterine growth restriction, spontaneous abortion and microcephaly in newborns. Here we show using biologically relevant cells of neural and placental origin that following ZIKV infection, there is attenuation of the cellular innate response characterised by reduced expression of IFN-β and associated interferon stimulated genes (ISGs). One such ISG is viperin that has well documented antiviral activity against a wide range of viruses. Expression of viperin in cultured cells resulted in significant impairment of ZIKV replication, while MEFs derived from CRISPR/Cas9 derived viperin-/- mice replicated ZIKV to higher titers compared to their WT counterparts. These results suggest that ZIKV can attenuate ISG expression to avoid the cellular antiviral innate response, thus allowing the virus to replicate unchecked. Moreover, we have identified that the ISG viperin has significant anti-ZIKV activity. Further understanding of how ZIKV perturbs the ISG response and the molecular mechanisms utilised by viperin to suppress ZIKV replication will aid in our understanding of ZIKV biology, pathogenesis and possible design of novel antiviral strategies.Kylie H. Van der Hoek, Nicholas S. Eyre, Byron Shue, Onruedee Khantisitthiporn, Kittirat Glab-Ampi, Jillian M. Carr, Matthew J. Gartner, Lachlan A. Jolly, Paul Q. Thomas, Fatwa Adikusuma, Tanja Jankovic-Karasoulos, Claire T. Roberts, Karla J. Helbig and Michael R. Bear

    Humanity or justice?

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    This paper reflects on a critique of cosmopolitanism mounted by Tom Campbell, who argues that cosmopolitans place undue stress on the issue of global justice. Campbell argues that aid for the impoverished needy in the third world, for example, should be given on the Principle of Humanity rather than on the Principle of Justice. This line of thought is also pursued by ‘Liberal Nationalists’ like Yael Tamir and David Miller. Thomas Nagel makes a similar distinction and questions whether the ideal of justice can even be meaningfully applied on a global scale. The paper explores whether the distinction between the Principle of Humanity and the Principle of Justice might be a false dichotomy in that both principles could be involved in humanitarian assistance. It will suggest that both principles might be grounded in an ethics of caring and that the ethics of caring cannot be so sharply distinguished from the discourse of justice and of rights. As a result, the Principle of Humanity and the Principle of Justice cannot be so sharply distinguished either. It is because we care about others as human beings (Principle of Humanity) that we pursue justice for them (Principle of Justice) and the alleviation of their avoidable suffering

    Which executive functioning deficits are associated with AD/HD, ODD/CD and comorbid AD/HD+ODD/CD?

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    Item does not contain fulltextThis study investigated (1) whether attention deficit/hyperactivity disorder (AD/HD) is associated with executive functioning (EF) deficits while controlling for oppositional defiant disorder/conduct disorder (ODD/CD), (2) whether ODD/CD is associated with EF deficits while controlling for AD/HD, and (3)~whether a combination of AD/HD and ODD/CD is associated with EF deficits (and the possibility that there is no association between EF deficits and AD/HD or ODD/CD in isolation). Subjects were 99~children ages 6–12 years. Three putative domains of EF were investigated using well-validated tests: verbal fluency, working memory, and planning. Independent of ODD/CD, AD/HD was associated with deficits in planning and working memory, but not in verbal fluency. Only teacher rated AD/HD, but not parent rated AD/HD, significantly contributed to the prediction of EF task performance. No EF deficits were associated with ODD/CD. The presence of comorbid AD/HD accounts for the EF deficits in children with comorbid AD/HD+ODD/CD. These results suggest that EF deficits are unique to AD/HD and support the model proposed by R. A. Barkley (1997).17 p

    MeV magnetosheath ions energized at the bow shock

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    A causal relationship between midlatitude magnetosheath energetic ions and bow shock magnetic geometry was previously established for ion energy up to 200 keV e−1 for the May 4, 1998, storm event. This study demonstrates that magnetosheath ions with energies above 200 keV up to 1 MeV simply extend the ion spectrum to form a power law tail. Results of cross-correlation analysis suggest that these ions also come directly from the quasi-parallel bow shock, not the magnetosphere. This is confirmed by a comparison of energetic ion fluxes simultaneously measured in the magnetosheath and at the quasi-parallel bow shock when both regions are likely connected by the magnetic field lines. We suggest that ions are accelerated at the quasi-parallel bow shock to energies as high as 1 MeV and subsequently transported into the magnetosheath during this event

    Challenges in QCD matter physics - The Compressed Baryonic Matter experiment at FAIR

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    Substantial experimental and theoretical efforts worldwide are devoted to explore the phase diagram of strongly interacting matter. At LHC and top RHIC energies, QCD matter is studied at very high temperatures and nearly vanishing net-baryon densities. There is evidence that a Quark-Gluon-Plasma (QGP) was created at experiments at RHIC and LHC. The transition from the QGP back to the hadron gas is found to be a smooth cross over. For larger net-baryon densities and lower temperatures, it is expected that the QCD phase diagram exhibits a rich structure, such as a first-order phase transition between hadronic and partonic matter which terminates in a critical point, or exotic phases like quarkyonic matter. The discovery of these landmarks would be a breakthrough in our understanding of the strong interaction and is therefore in the focus of various high-energy heavy-ion research programs. The Compressed Baryonic Matter (CBM) experiment at FAIR will play a unique role in the exploration of the QCD phase diagram in the region of high net-baryon densities, because it is designed to run at unprecedented interaction rates. High-rate operation is the key prerequisite for high-precision measurements of multi-differential observables and of rare diagnostic probes which are sensitive to the dense phase of the nuclear fireball. The goal of the CBM experiment at SIS100 (sqrt(s_NN) = 2.7 - 4.9 GeV) is to discover fundamental properties of QCD matter: the phase structure at large baryon-chemical potentials (mu_B > 500 MeV), effects of chiral symmetry, and the equation-of-state at high density as it is expected to occur in the core of neutron stars. In this article, we review the motivation for and the physics programme of CBM, including activities before the start of data taking in 2022, in the context of the worldwide efforts to explore high-density QCD matter.Comment: 15 pages, 11 figures. Published in European Physical Journal
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