270 research outputs found

    Aspergillus hancockii sp. Nov., a biosynthetically talented fungus endemic to southeastern Australian soils

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    Aspergillus hancockii sp. nov., classified in Aspergillus subgenus Circumdati section Flavi, was originally isolated from soil in peanut fields near Kumbia, in the South Burnett region of southeast Queensland, Australia, and has since been found occasionally from other substrates and locations in southeast Australia. It is phylogenetically and phenotypically related most closely to A. leporis States and M. Chr., but differs in conidial colour, other minor features and particularly in metabolite profile. When cultivated on rice as an optimal substrate, A. hancockii produced an extensive array of 69 secondary metabolites. Eleven of the 15 most abundant secondary metabolites, constituting 90% of the total area under the curve of the HPLC trace of the crude extract, were novel. The genome of A. hancockii, approximately 40 Mbp, was sequenced and mined for genes encoding carbohydrate degrading enzymes identified the presence of more than 370 genes in 114 gene clusters, demonstrating that A. hancockii has the capacity to degrade cellulose, hemicellulose, lignin, pectin, starch, chitin, cutin and fructan as nutrient sources. Like most Aspergillus species, A. hancockii exhibited a diverse secondary metabolite gene profile, encoding 26 polyketide synthase, 16 nonribosomal peptide synthase and 15 nonribosomal peptide synthase-like enzymes

    Divergent roles for antigenic drive in the aetiology of primary versus dasatinib-associated CD8(+) TCR-Vβ(+) expansions

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    CD8(+) T-cell expansions are the primary manifestation of T-cell large granular lymphocytic leukemia (T-LGLL), which is frequently accompanied by neutropenia and rheumatoid arthritis, and also occur as a secondary phenomenon in leukemia patients treated with dasatinib, notably in association with various drug-induced side-effects. However, the mechanisms that underlie the genesis and maintenance of expanded CD8(+) T-cell receptor (TCR)-V beta(+) populations in these patient groups have yet to be fully defined. In this study, we performed a comprehensive phenotypic and clonotypic assessment of expanded (TCR-V beta(+)) and residual (TCR-V beta(-)) CD8(+) T-cell populations in T-LGLL and dasatinib-treated chronic myelogenous leukemia (CML) patients. The dominant CD8(+) TCR-V beta(+) expansions in T-LGLL patients were largely monoclonal and highly differentiated, whereas the dominant CD8(+) TCR-V beta(+) expansions in dasatinib-treated CML patients were oligoclonal or polyclonal, and displayed a broad range of memory phenotypes. These contrasting features suggest divergent roles for antigenic drive in the immunopathogenesis of primary versus dasatinib-associated CD8(+) TCR-V beta(+) expansions.Peer reviewe

    p-tau Ser356 is associated with Alzheimer's disease pathology and is lowered in brain slice cultures using the NUAK inhibitor WZ4003

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    Tau hyperphosphorylation and aggregation is a common feature of many dementia-causing neurodegenerative diseases. Tau can be phosphorylated at up to 85 different sites, and there is increasing interest in whether tau phosphorylation at specific epitopes, by specific kinases, plays an important role in disease progression. The AMP-activated protein kinase (AMPK)-related enzyme NUAK1 has been identified as a potential mediator of tau pathology, whereby NUAK1-mediated phosphorylation of tau at Ser356 prevents the degradation of tau by the proteasome, further exacerbating tau hyperphosphorylation and accumulation. This study provides a detailed characterisation of the association of p-tau Ser356 with progression of Alzheimer's disease pathology, identifying a Braak stage-dependent increase in p-tau Ser356 protein levels and an almost ubiquitous presence in neurofibrillary tangles. We also demonstrate, using sub-diffraction-limit resolution array tomography imaging, that p-tau Ser356 co-localises with synapses in AD postmortem brain tissue, increasing evidence that this form of tau may play important roles in AD progression. To assess the potential impacts of pharmacological NUAK inhibition in an ex vivo system that retains multiple cell types and brain-relevant neuronal architecture, we treated postnatal mouse organotypic brain slice cultures from wildtype or APP/PS1 littermates with the commercially available NUAK1/2 inhibitor WZ4003. Whilst there were no genotype-specific effects, we found that WZ4003 results in a culture-phase-dependent loss of total tau and p-tau Ser356, which corresponds with a reduction in neuronal and synaptic proteins. By contrast, application of WZ4003 to live human brain slice cultures results in a specific lowering of p-tau Ser356, alongside increased neuronal tubulin protein. This work identifies differential responses of postnatal mouse organotypic brain slice cultures and adult human brain slice cultures to NUAK1 inhibition that will be important to consider in future work developing tau-targeting therapeutics for human disease.</p

    An analysis of baseline data from the PROUD study: an open-label randomised trial of pre-exposure prophylaxis

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    Background: Pre-exposure prophylaxis (PrEP) has proven biological efficacy to reduce the sexual acquisition of the human immunodeficiency virus (HIV). The PROUD study found that PrEP conferred higher protection than in placebo-controlled trials, reducing HIV incidence by 86 % in a population with seven-fold higher HIV incidence than expected. We present the baseline characteristics of the PROUD study population and place the findings in the context of national sexual health clinic data. Methods: The PROUD study was designed to explore the real-world effectiveness of PrEP (tenofovir-emtricitabine) by randomising HIV-negative gay and other men who have sex with men (GMSM) to receive open-label PrEP immediately or after a deferral period of 12 months. At enrolment, participants self-completed two baseline questionnaires collecting information on demographics, sexual behaviour and lifestyle in the last 30 and 90 days. These data were compared to data from HIV-negative GMSM attending sexual health clinics in 2013, collated by Public Health England using the genitourinary medicine clinic activity database (GUMCAD). Results: The median age of participants was 35 (IQR: 29–43). Typically participants were white (81 %), educated at a university level (61 %) and in full-time employment (72 %). Of all participants, 217 (40 %) were born outside the UK. A sexually transmitted infection (STI) was reported to have been diagnosed in the previous 12 months in 330/515 (64 %) and 473/544 (87 %) participants reported ever having being diagnosed with an STI. At enrolment, 47/280 (17 %) participants were diagnosed with an STI. Participants reported a median (IQR) of 10 (5–20) partners in the last 90 days, a median (IQR) of 2 (1–5) were condomless sex acts where the participant was receptive and 2 (1–6) were condomless where the participant was insertive. Post-exposure prophylaxis had been prescribed to 184 (34 %) participants in the past 12 months. The number of STI diagnoses was high compared to those reported in GUMCAD attendees. Conclusions: The PROUD study population are at substantially higher risk of acquiring HIV infection sexually than the overall population of GMSM attending sexual health clinics in England. These findings contribute to explaining the extraordinary HIV incidence rate during follow-up and demonstrate that, despite broad eligibility criteria, the population interested in PrEP was highly selective. Trial registration: Current Controlled TrialsISRCTN94465371. Date of registration: 28 February 2013

    Double Spin Asymmetry of Electrons from Heavy Flavor Decays in p+p Collisions at sqrt(s)=200 GeV

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    We report on the first measurement of double-spin asymmetry, A_LL, of electrons from the decays of hadrons containing heavy flavor in longitudinally polarized p+p collisions at sqrt(s)=200 GeV for p_T= 0.5 to 3.0 GeV/c. The asymmetry was measured at mid-rapidity (|eta|<0.35) with the PHENIX detector at the Relativistic Heavy Ion Collider. The measured asymmetries are consistent with zero within the statistical errors. We obtained a constraint for the polarized gluon distribution in the proton of |Delta g/g(log{_10}x= -1.6^+0.5_-0.4, {mu}=m_T^c)|^2 < 0.033 (1 sigma), based on a leading-order perturbative-quantum-chromodynamics model, using the measured asymmetry.Comment: 385 authors, 17 pages, 15 figures, 5 tables. Submitted to Phys. Rev. D. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are (or will be) publicly available at http://www.phenix.bnl.gov/papers.htm

    Measurement of long-range angular correlation and quadrupole anisotropy of pions and (anti)protons in central dd++Au collisions at sNN\sqrt{s_{_{NN}}}=200 GeV

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    We present azimuthal angular correlations between charged hadrons and energy deposited in calorimeter towers in central dd++Au and minimum bias pp++pp collisions at sNN=200\sqrt{s_{_{NN}}}=200 GeV. The charged hadron is measured at midrapidity η<0.35|\eta|<0.35, and the energy is measured at large rapidity (3.7<η<3.1-3.7<\eta<-3.1, Au-going direction). An enhanced near-side angular correlation across Δη>|\Delta\eta| > 2.75 is observed in dd++Au collisions. Using the event plane method applied to the Au-going energy distribution, we extract the anisotropy strength v2v_2 for inclusive charged hadrons at midrapidity up to pT=4.5p_T=4.5 GeV/cc. We also present the measurement of v2v_2 for identified π±\pi^{\pm} and (anti)protons in central dd++Au collisions, and observe a mass-ordering pattern similar to that seen in heavy ion collisions. These results are compared with viscous hydrodynamic calculations and measurements from pp++Pb at sNN=5.02\sqrt{s_{_{NN}}}=5.02 TeV. The magnitude of the mass-ordering in dd++Au is found to be smaller than that in pp++Pb collisions, which may indicate smaller radial flow in lower energy dd++Au collisions.Comment: 424 authors, 8 pages, and 4 figures. v2 is version accepted for publication in Phys. Rev. Lett. Published version will be at http://www.phenix.bnl.gov/phenix/WWW/info/pp1/161/ Plain text data tables will be at http://www.phenix.bnl.gov/papers.htm

    Cold-nuclear-matter effects on heavy-quark production at forward and backward rapidity in d+Au collisions at sqrt(s_NN)=200 GeV

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    The PHENIX experiment has measured open heavy-flavor production via semileptonic decay muons over the transverse momentum range 1 < pT < 6 GeV/c at forward and backward rapidity (1.4 < |y| < 2.0) in d+Au and p+p collisions at ?sNN = 200 GeV. In central d+Au collisions an enhancement (suppression) of heavy-flavor muon production is observed at backward (forward) rapidity relative to the yield in p+p collisions scaled by the number of binary collisions. Modification of the gluon density distribution in the Au nucleus contributes in terms of anti-shadowing enhancement and shadowing suppression; however, the enhancement seen at backward rapidity exceeds expectations from this effect alone. These results, implying an important role for additional cold nuclear matter effects, serves as a key baseline for heavy-quark measurements in A+A collisions and in constraining the magnitude of charmonia breakup effects at the Relativistic Heavy Ion Collider and the Large Hadron Collider.Comment: 424 authors, 69 insitutions, 8 pages, 4 figures. Submitted to Physical Review Letters. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are (or will be) publicly available at http://www.phenix.bnl.gov/papers.htm

    Upsilon (1S+2S+3S) production in d+Au and p+p collisions at sqrt(s_NN)=200 GeV and cold-nuclear matter effects

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    The three Upsilon states, Upsilon(1S+2S+3S), are measured in d+Au and p+p collisions at sqrt(s_NN)=200 GeV and rapidities 1.2<|y|<2.2 by the PHENIX experiment at the Relativistic Heavy-Ion Collider. Cross sections for the inclusive Upsilon(1S+2S+3S) production are obtained. The inclusive yields per binary collision for d+Au collisions relative to those in p+p collisions (R_dAu) are found to be 0.62 +/- 0.26 (stat) +/- 0.13 (syst) in the gold-going direction and 0.91 +/- 0.33 (stat) +/- 0.16 (syst) in the deuteron-going direction. The measured results are compared to a nuclear-shadowing model, EPS09 [JHEP 04, 065 (2009)], combined with a final-state breakup cross section, sigma_br, and compared to lower energy p+A results. We also compare the results to the PHENIX J/psi results [Phys. Rev. Lett. 107, 142301 (2011)]. The rapidity dependence of the observed Upsilon suppression is consistent with lower energy p+A measurements.Comment: 495 authors, 11 pages, 9 figures, 5 tables. Submitted to Phys. Rev. C. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are (or will be) publicly available at http://www.phenix.bnl.gov/papers.htm
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