39 research outputs found

    Multiple Continental Radiations and Correlates of Diversification in Lupinus (Leguminosae): Testing for Key Innovation with Incomplete Taxon Sampling

    Get PDF
    Replicate radiations provide powerful comparative systems to address questions about the interplay between opportunity and innovation in driving episodes of diversification and the factors limiting their subsequent progression. However, such systems have been rarely documented at intercontinental scales. Here, we evaluate the hypothesis of multiple radiations in the genus Lupinus (Leguminosae), which exhibits some of the highest known rates of net diversification in plants. Given that incomplete taxon sampling, background extinction, and lineage-specific variation in diversification rates can confound macroevolutionary inferences regarding the timing and mechanisms of cladogenesis, we used Bayesian relaxed clock phylogenetic analyses as well as MEDUSA and BiSSE birth-death likelihood models of diversification, to evaluate the evolutionary patterns of lineage accumulation in Lupinus. We identified 3 significant shifts to increased rates of net diversification (r) relative to background levels in the genus (r = 0.18-0.48 lineages/myr). The primary shift occurred approximately 4.6 Ma (r = 0.48-1.76) in the montane regions of western North America, followed by a secondary shift approximately 2.7 Ma (r = 0.89-3.33) associated with range expansion and diversification of allopatrically distributed sister clades in the Mexican highlands and Andes. We also recovered evidence for a third independent shift approximately 6.5 Ma at the base of a lower elevation eastern South American grassland and campo rupestre clade (r = 0.36-1.33). Bayesian ancestral state reconstructions and BiSSE likelihood analyses of correlated diversification indicated that increased rates of speciation are strongly associated with the derived evolution of perennial life history and invasion of montane ecosystems. Although we currently lack hard evidence for "replicate adaptive radiations” in the sense of convergent morphological and ecological trajectories among species in different clades, these results are consistent with the hypothesis that iteroparity functioned as an adaptive key innovation, providing a mechanism for range expansion and rapid divergence in upper elevation regions across much of the New Worl

    Serum IgG against Simian Virus 40 antigens are hampered by high levels of sHLA-G in patients affected by inflammatory neurological diseases, as multiple sclerosis

    Get PDF
    Background: Many investigators detected the simian polyomavirus SV40 footprints in human brain tumors and neurologic diseases and recently it has been indicated that SV40 seems to be associated with multiple sclerosis (MS) disease. Interestingly, SV40 interacts with human leukocyte antigen (HLA) class I molecules for cell entry. HLA class I antigens, in particular non-classical HLA-G molecules, characterized by an immune-regulatory function, are involved in MS disease, and the levels of these molecules are modified according with the disease status. Objective: We investigated in serum samples, from Italian patients affected by MS, other inflammatory diseases (OIND), non-inflammatory neurological diseases (NIND) and healthy subjects (HS), SV40-antibody and soluble sHLA-G and the association between SV40-prevalence and sHLA-G levels. Methods: ELISA tests were used for SV40-antibodies detection and sHLA-G quantitation in serum samples. Results: The presence of SV40 antibodies was observed in 6 % of patients affected by MS (N = 4/63), 10 % of OIND (N = 8/77) and 15 % of NIND (N = 9/59), which is suggestive of a lower prevalence in respect to HS (22 %, N = 18/83). MS patients are characterized by higher sHLA-G serum levels (13.9 \ub1 0.9 ng/ml; mean \ub1 St. Error) in comparison with OIND (6.7 \ub1 0.8 ng/ml), NIND (2.9 \ub1 0.4 ng/ml) and HS (2.6 \ub1 0.7 ng/ml) subjects. Interestingly, we observed an inverse correlation between SV40 antibody prevalence and sHLA-G serum levels in MS patients. Conclusion: The data obtained showed a low prevalence of SV40 antibodies in MS patients. These results seems to be due to a generalized status of inability to counteract SV40 infection via antibody production. In particular, we hypothesize that SV40 immune-inhibitory direct effect and the presence of high levels of the immune-inhibitory HLA-G molecules could co-operate in impairing B lymphocyte activation towards SV40 specific peptides

    A search for an excited muon decaying to a muon and two jets in pp collisions at √s = 8 TeV with the ATLAS detector

    Get PDF
    A new search signature for excited leptons is explored. Excited muons are sought in the channel ppμμμμ jet jetpp \to \mu\mu^* \to \mu \mu\textrm{ jet jet}, assuming both the production and decay occur via a contact interaction. The analysis is based on 20.3 fb1^{-1} of pppp collision data at a centre-of-mass energy of s\sqrt{s} = 8 TeV taken with the ATLAS detector at the Large Hadron Collider. No evidence of excited muons is found, and limits are set at the 95% confidence level on the cross section times branching ratio as a function of the excited-muon mass mμm_{\mu^*}. For mμm_{\mu^*} between 1.3 TeV and 3.0 TeV, the upper limit on σB(μμqqˉ\sigma B(\mu^* \to \mu q \bar{q}) is between 0.6 and 1 fb. Limits on σB\sigma B are converted to lower bounds on the compositeness scale Λ\Lambda. In the limiting case Λ=mμ\Lambda = m_{\mu^*}, excited muons with a mass below 2.9 TeV are excluded. With the same model assumptions, these limits at larger μ\mu^* masses improve upon previous limits from traditional searches based on the gauge-mediated decay μμγ\mu^* \to \mu \gamma.Comment: 33 pages in total, author list starting page 16, 4 figures, 5 tables, final version published by New Journal of Physics including corrections in Erratum https://dx.doi.org/10.1088/1367-2630/ab46ed. All figures including auxiliary are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/EXOT-2015-0

    Search for anomalous electroweak production of WW/WZ in association with a high-mass dijet system in pp collisions at √s=8  TeV with the ATLAS detector

    Get PDF
    A search is presented for anomalous quartic gauge boson couplings in vector-boson scattering. The data for the analysis correspond to 20.220.2 fb1^{-1} of s=8\sqrt{s}=8 TeV pppp collisions, and were collected in 2012 by the ATLAS experiment at the Large Hadron Collider. The search looks for the production of WWWW or WZWZ boson pairs accompanied by a high-mass dijet system, with one WW decaying leptonically, and a WW or ZZ decaying hadronically. The hadronically decaying W/ZW/Z is reconstructed as either two small-radius jets or one large-radius jet using jet substructure techniques. Constraints on the anomalous quartic gauge boson coupling parameters α4\alpha_4 and α5\alpha_5 are set by fitting the transverse mass of the diboson system, and the resulting 95% confidence intervals are 0.024<α4<0.030-0.024<\alpha_4<0.030 and 0.028<α5<0.033-0.028<\alpha_5<0.033.Comment: 38 pages in total, author list starting page 22, 5 figures, 2 tables, published in Phys. Rev. D. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2015-09

    Dementia in Latin America : paving the way towards a regional action plan

    Get PDF
    Regional challenges faced by Latin American and Caribbean countries (LACs) to fight dementia, such as heterogeneity, diversity, political instabilities, and socioeconomic disparities, can be addressed more effectively grounded in a collaborative setting based on the open exchange of knowledge. In this work, the Latin American and Caribbean Consortium on Dementia (LAC-CD) proposes an agenda for integration to deliver a Knowledge to Action Framework (KtAF). First, we summarize evidence-based strategies (epidemiology, genetics, biomarkers, clinical trials, nonpharmacological interventions, networking and translational research) and align them to current global strategies to translate regional knowledge into actions with transformative power. Then, by characterizing genetic isolates, admixture in populations, environmental factors, and barriers to effective interventions and mapping these to the above challenges, we provide the basic mosaics of knowledge that will pave the way towards a KtAF. We describe strategies supporting the knowledge creation stage that underpins the translational impact of KtAF

    Measurement of jet fragmentation in Pb+Pb and pppp collisions at sNN=2.76\sqrt{{s_\mathrm{NN}}} = 2.76 TeV with the ATLAS detector at the LHC

    Get PDF

    Measurement of the W boson polarisation in ttˉt\bar{t} events from pp collisions at s\sqrt{s} = 8 TeV in the lepton + jets channel with ATLAS

    Get PDF

    Search for new phenomena in events containing a same-flavour opposite-sign dilepton pair, jets, and large missing transverse momentum in s=\sqrt{s}= 13 pppp collisions with the ATLAS detector

    Get PDF
    corecore