Seasonal variation of the transport of black carbon aerosol from the Asian continent to the Arctic during the ARCTAS aircraft campaign

Extensive measurements of black carbon (BC) aerosol were conducted in and near the North American Arctic during the Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) aircraft campaign in April and June-July 2008. We identify the pathways and mechanisms of transport of BC to the Arctic from the Asian continent using these data. The concentration, transport efficiency, and measured altitude of BC over the North American Arctic were highly dependent on season and origin of air parcels, e.g., biomass burning (BB) in Russia (Russian BB) and anthropogenic (AN) in East Asia (Asian AN). Russian BB air was mainly measured in the middle troposphere and caused maximum BC concentrations at this altitude in spring. The median BC concentration and transport efficiency of the Russian BB air were 270 ng m -3 (at STP) and 80% in spring and 20 ng m-3 and 4% in summer, respectively. Asian AN air was measured most frequently in the upper troposphere, with median values of 20 ng m-3 and 13% in spring and 5 ng m-3 and 0.8% in summer. These distinct differences are explained by differences in the transport mechanisms and accumulated precipitation along trajectories (APT), which is a measure of wet removal processes during transport. The transport of Russian BB air to the Arctic was nearly isentropic with slow ascent (low APT), while Asian AN air underwent strong uplift associated with warm conveyor belts (high APT). The APT values in summer were much larger than those in spring due to the increase in humidity in summer. These results show that the impact of BC emitted from AN sources in East Asia on the Arctic was very limited in both spring and summer. The BB emissions in Russia in spring are demonstrated to be the most important sources of BC transported to the North American Arctic. Copyright 2011 by the American Geophysical Union

Accumulation-mode aerosol number concentrations in the Arctic during the ARCTAS aircraft campaign: Long-range transport of polluted and clean air from the Asian continent

We evaluate the impact of transport from midlatitudes on aerosol number concentrations in the accumulation mode (light-scattering particles (LSP) with diameters >180 nm) in the Arctic during the Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) campaign. We focus on transport from the Asian continent. We find marked contrasts in the number concentration (NLSP), transport efficiency (TE N-LSP, the fraction transported from sources to the Arctic), size distribution, and the chemical composition of aerosols between air parcels from anthropogenic sources in East Asia (Asian AN) and biomass burning sources in Russia and Kazakhstan (Russian BB). Asian AN air had lower NLSP and TEN-LSP (25 cm-3 and 18% in spring and 6.2 cm-3 and 3.0% in summer) than Russian BB air (280 cm-3 and 97% in spring and 36 cm-3 and 7.6% in summer) due to more efficient wet scavenging during transport from East Asia. Russian BB in this spring is the most important source of accumulation-mode aerosols over the Arctic, and BB emissions are found to be the primary source of aerosols within all the data in spring during ARCTAS. On the other hand, the contribution of Asian AN transport had a negligible effect on the accumulation-mode aerosol number concentration in the Arctic during ARCTAS. Compared with background air, NLSP was 2.3-4.7 times greater for Russian BB air but 2.4-2.6 times less for Asian AN air in both spring and summer. This result shows that the transport of Asian AN air decreases aerosol number concentrations in the Arctic, despite the large emissions of aerosols in East Asia. The very low aerosol number concentrations in Asian AN air were caused by wet removal during vertical transport in association with warm conveyor belts (WCBs). Therefore, this cleansing effect will be prominent for air transported via WCBs from other midlatitude regions and seasons. The inflow of clean midlatitude air can potentially have an important impact on accumulation-mode aerosol number concentrations in the Arctic. Copyright 2011 by the American Geophysical Union

1-year results of combined half-dose photodynamic therapy and ranibizumab for polypoidal choroidal vasculopathy

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Laimaphelenchus suberensis sp. nov. associated with Quercus suber in Portugal

Laimaphelenchus suberensis sp. nov. obtained from declining Quercus suber trees of Herdade da Gouveia de Baixo, Alentejo, Portugal, is described and illustrated based on morphological, biometrical and molecular characters. The diagnosis of Laimaphelenchus species has been commonly based on the presence or absence of a vulval flap and on the shape structure of the tail tip. The species described here has been included in the Laimaphelenchus group without vulval flap, and can be distinguished from morphologically similar species by its tail tip shape structure that has a stalk-like terminus and three diffuse tubercles with 4–6 finger-like protrusions. For the molecular analyses, the mitochondrial DNA region from the cytochrome oxidase subunit I (mtCOI), the D2-D3 expansion segments of the large subunit (LSU) and small subunit (SSU) of rRNA gene were amplified and sequenced. Sequences of L. suberensis sp. nov. clustered separately from all Laimaphelenchus spp. with available sequences in Genbank, confirming its identification as a new species. This is the second report of the genus Laimaphelenchus in Portugal, associated with Q. suber: L. heidelbergi and L. suberensis sp. nov.This research was supported by CFE, CIEPQPF and FEDER funds through the ‘Programa Operacional Factores de Competitividade – COMPETE’ and by national funds through FCT–Fundação para a Ciência e a Tecnologia under the projects UID/BIA/04004/2013, PEst-C/EQB/UI0102/2013 and FCOMP-01-0124-008937 (Ref. PTDC/BIA–BEC/102834/2008) and by Instituto do Ambiente, Tecnologia e Vida (IATV). Carla Maleita (SFRH/BPD/85736/2012) and Sofia Costa (SFRH/BPD/ 102438/2014) were financed by MEC National funding and The European Social Fund through POCH (Programa Operacional Capital Humano).info:eu-repo/semantics/publishedVersio

The Endogenous Th17 Response in NO<inf>2</inf>-Promoted Allergic Airway Disease Is Dispensable for Airway Hyperresponsiveness and Distinct from Th17 Adoptive Transfer

Severe, glucocorticoid-resistant asthma comprises 5-7% of patients with asthma. IL-17 is a biomarker of severe asthma, and the adoptive transfer of Th17 cells in mice is sufficient to induce glucocorticoid-resistant allergic airway disease. Nitrogen dioxide (NO2) is an environmental toxin that correlates with asthma severity, exacerbation, and risk of adverse outcomes. Mice that are allergically sensitized to the antigen ovalbumin by exposure to NO2 exhibit a mixed Th2/Th17 adaptive immune response and eosinophil and neutrophil recruitment to the airway following antigen challenge, a phenotype reminiscent of severe clinical asthma. Because IL-1 receptor (IL-1R) signaling is critical in the generation of the Th17 response in vivo, we hypothesized that the IL-1R/Th17 axis contributes to pulmonary inflammation and airway hyperresponsiveness (AHR) in NO2-promoted allergic airway disease and manifests in glucocorticoid-resistant cytokine production. IL-17A neutralization at the time of antigen challenge or genetic deficiency in IL-1R resulted in decreased neutrophil recruitment to the airway following antigen challenge but did not protect against the development of AHR. Instead, IL-1R-/- mice developed exacerbated AHR compared to WT mice. Lung cells from NO2-allergically inflamed mice that were treated in vitro with dexamethasone (Dex) during antigen restimulation exhibited reduced Th17 cytokine production, whereas Th17 cytokine production by lung cells from recipient mice of in vitro Th17-polarized OTII T-cells was resistant to Dex. These results demonstrate that the IL-1R/Th17 axis does not contribute to AHR development in NO2-promoted allergic airway disease, that Th17 adoptive transfer does not necessarily reflect an endogenously-generated Th17 response, and that functions of Th17 responses are contingent on the experimental conditions in which they are generated. © 2013 Martin et al

Observation of a ppb mass threshoud enhancement in \psi^\prime\to\pi^+\pi^-J/\psi(J/\psi\to\gamma p\bar{p}) decay

The decay channel $\psi^\prime\to\pi^+\pi^-J/\psi(J/\psi\to\gamma p\bar{p})$ is studied using a sample of $1.06\times 10^8$ $\psi^\prime$ events collected by the BESIII experiment at BEPCII. A strong enhancement at threshold is observed in the $p\bar{p}$ invariant mass spectrum. The enhancement can be fit with an $S$-wave Breit-Wigner resonance function with a resulting peak mass of $M=1861^{+6}_{-13} {\rm (stat)}^{+7}_{-26} {\rm (syst)} {\rm MeV/}c^2$ and a narrow width that is $\Gamma<38 {\rm MeV/}c^2$ at the 90% confidence level. These results are consistent with published BESII results. These mass and width values do not match with those of any known meson resonance.Comment: 5 pages, 3 figures, submitted to Chinese Physics

Selective area epitaxy of ultra-high density InGaN quantum dots by diblock copolymer lithography

Highly uniform InGaN-based quantum dots (QDs) grown on a nanopatterned dielectric layer defined by self-assembled diblock copolymer were performed by metal-organic chemical vapor deposition. The cylindrical-shaped nanopatterns were created on SiNx layers deposited on a GaN template, which provided the nanopatterning for the epitaxy of ultra-high density QD with uniform size and distribution. Scanning electron microscopy and atomic force microscopy measurements were conducted to investigate the QDs morphology. The InGaN/GaN QDs with density up to 8 × 1010 cm-2 are realized, which represents ultra-high dot density for highly uniform and well-controlled, nitride-based QDs, with QD diameter of approximately 22-25 nm. The photoluminescence (PL) studies indicated the importance of NH3 annealing and GaN spacer layer growth for improving the PL intensity of the SiNx-treated GaN surface, to achieve high optical-quality QDs applicable for photonics devices

Coevolved mutations reveal distinct architectures for two core proteins in the bacterial flagellar motor

Switching of bacterial flagellar rotation is caused by large domain movements of the FliG protein triggered by binding of the signal protein CheY to FliM. FliG and FliM form adjacent multi-subunit arrays within the basal body C-ring. The movements alter the interaction of the FliG C-terminal (FliGC) "torque" helix with the stator complexes. Atomic models based on the Salmonella entrovar C-ring electron microscopy reconstruction have implications for switching, but lack consensus on the relative locations of the FliG armadillo (ARM) domains (amino-terminal (FliGN), middle (FliGM) and FliGC) as well as changes during chemotaxis. The generality of the Salmonella model is challenged by the variation in motor morphology and response between species. We studied coevolved residue mutations to determine the unifying elements of switch architecture. Residue interactions, measured by their coevolution, were formalized as a network, guided by structural data. Our measurements reveal a common design with dedicated switch and motor modules. The FliM middle domain (FliMM) has extensive connectivity most simply explained by conserved intra and inter-subunit contacts. In contrast, FliG has patchy, complex architecture. Conserved structural motifs form interacting nodes in the coevolution network that wire FliMM to the FliGC C-terminal, four-helix motor module (C3-6). FliG C3-6 coevolution is organized around the torque helix, differently from other ARM domains. The nodes form separated, surface-proximal patches that are targeted by deleterious mutations as in other allosteric systems. The dominant node is formed by the EHPQ motif at the FliMMFliGM contact interface and adjacent helix residues at a central location within FliGM. The node interacts with nodes in the N-terminal FliGc α-helix triad (ARM-C) and FliGN. ARM-C, separated from C3-6 by the MFVF motif, has poor intra-network connectivity consistent with its variable orientation revealed by structural data. ARM-C could be the convertor element that provides mechanistic and species diversity.JK was supported by Medical Research Council grant U117581331. SK was supported by seed funds from Lahore University of Managment Sciences (LUMS) and the Molecular Biology Consortium

Microbial ligand costimulation drives neutrophilic steroid-refractory asthma

Funding: The authors thank the Wellcome Trust (102705) and the Universities of Aberdeen and Cape Town for funding. This research was also supported, in part, by National Institutes of Health GM53522 and GM083016 to DLW. KF and BNL are funded by the Fonds Wetenschappelijk Onderzoek, BNL is the recipient of an European Research Commission consolidator grant and participates in the European Union FP7 programs EUBIOPRED and MedALL. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewedPublisher PD

Control of intestinal stem cell function and proliferation by mitochondrial pyruvate metabolism.

Most differentiated cells convert glucose to pyruvate in the cytosol through glycolysis, followed by pyruvate oxidation in the mitochondria. These processes are linked by the mitochondrial pyruvate carrier (MPC), which is required for efficient mitochondrial pyruvate uptake. In contrast, proliferative cells, including many cancer and stem cells, perform glycolysis robustly but limit fractional mitochondrial pyruvate oxidation. We sought to understand the role this transition from glycolysis to pyruvate oxidation plays in stem cell maintenance and differentiation. Loss of the MPC in Lgr5-EGFP-positive stem cells, or treatment of intestinal organoids with an MPC inhibitor, increases proliferation and expands the stem cell compartment. Similarly, genetic deletion of the MPC in Drosophila intestinal stem cells also increases proliferation, whereas MPC overexpression suppresses stem cell proliferation. These data demonstrate that limiting mitochondrial pyruvate metabolism is necessary and sufficient to maintain the proliferation of intestinal stem cells