1,767 research outputs found

    Ozone and haze pollution weakens net primary productivity in China

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    Atmospheric pollutants have both beneficial and detrimental effects on carbon uptake by land ecosystems. Surface ozone (O3) damages leaf photosynthesis by oxidizing plant cells, while aerosols promote carbon uptake by increasing diffuse radiation and exert additional influences through concomitant perturbations to meteorology and hydrology. China is currently the world’s largest emitter of both carbon dioxide and short-lived air pollutants. The land ecosystems of China are estimated to provide a carbon sink, but it remains unclear whether air pollution acts to inhibit or promote carbon uptake. Here, we employ Earth system modeling and multiple measurement datasets to assess the separate and combined effects of anthropogenic O3 and aerosol pollution on net primary productivity (NPP) in China. In the present day, O3 reduces annual NPP by 0.6 Pg C (14 %) with a range from 0.4 Pg C (low O3 sensitivity) to 0.8 Pg C (high O3 sensitivity). In contrast, aerosol direct effects increase NPP by 0.2 Pg C (5 %) through the combination of diffuse radiation fertilization, reduced canopy temperatures, and reduced evaporation leading to higher soil moisture. Consequently, the net effects of O3 and aerosols decrease NPP by 0.4 Pg C (9 %) with a range from 0.2 Pg C (low O3 sensitivity) to 0.6 Pg C (high O3 sensitivity). However, precipitation inhibition from combined aerosol direct and indirect effects reduces annual NPP by 0.2 Pg C (4 %), leading to a net air pollution suppression of 0.8 Pg C (16 %) with a range from 0.6 Pg C (low O3 sensitivity) to 1.0 Pg C (high O3 sensitivity). Our results reveal strong dampening effects of air pollution on the land carbon uptake in China today. Following the current legislation emission scenario, this suppression will be further increased by the year 2030, mainly due to a continuing increase in surface O3. However, the maximum technically feasible reduction scenario could drastically relieve the current level of NPP damage by 70 % in 2030, offering protection of this critical ecosystem service and the mitigation of long-term global warming

    Butane-2,3-dione bis­[(4-bromo­benzyl­idene)hydrazone]

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    The title compound, C18H16Br2N4, is a linear double Schiff base compound having two parallel 4-bromo­phenyl groups connected across a crystallographic inversion centre by flexible C—C and C=N—N=C bonds and stabilized in the solid state by weak inter­molecular Br⋯Br inter­actions [3.7992 (11) Å], generating an infinite two-dimensional network structure

    Leukemia: Derived heat shock protein gp96-peptide complex contribution to T cell and dendritic cell activation

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    The molecular chaperone, heat shock protein gp96 (HSP-gp96), has been shown to have roles in the synthesis, processing and transport of tumor antigens. Therefore, the capacity for HSP-gp96 to induce dendritic cells (DCs), thymus-dependent lymphocytes (T lymphocytes), natural killer (NK) cells and cytotoxic T lymphocytes (CTLs) was investigated. Recombinant adenovirus (AD) containing HSP-gp96 (AD-gp96), as well as gp96-peptide complex from the human leukemia cell lines, K562, HL-60 and U937, was prepared. Purified gp96-peptide complex was found to stimulate the proliferation of T lymphocytes, increase the activity of NK cells and CTLs and induce the secretion of cytokines, compared with ADgp96. In the latter case, levels of IFN-γ and TNF-α were found to increase and levels of IL-12(P70) and IL- 10 decreased. In combination, these results indicated that the gp96-peptide complexes derived from the tumor cells contributed to the activation of lymphocytes and increase the presentation of tumor antigen. Furthermore, the chaperone function of gp96 promoted the maturation of DCs, enhanced the antigen presention function of DCs and induced the secretion of cytokines by DCs. Therefore, gp96-peptide complex derived from the tumor cells potentially represents an immunization therapy for the elimination of residual leukemia cells.Key words: Leukemia, heat shock protein gp96, dendritic cells, cytotoxic T lymphocytes

    AniPortraitGAN: Animatable 3D Portrait Generation from 2D Image Collections

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    Previous animatable 3D-aware GANs for human generation have primarily focused on either the human head or full body. However, head-only videos are relatively uncommon in real life, and full body generation typically does not deal with facial expression control and still has challenges in generating high-quality results. Towards applicable video avatars, we present an animatable 3D-aware GAN that generates portrait images with controllable facial expression, head pose, and shoulder movements. It is a generative model trained on unstructured 2D image collections without using 3D or video data. For the new task, we base our method on the generative radiance manifold representation and equip it with learnable facial and head-shoulder deformations. A dual-camera rendering and adversarial learning scheme is proposed to improve the quality of the generated faces, which is critical for portrait images. A pose deformation processing network is developed to generate plausible deformations for challenging regions such as long hair. Experiments show that our method, trained on unstructured 2D images, can generate diverse and high-quality 3D portraits with desired control over different properties.Comment: SIGGRAPH Asia 2023. Project Page: https://yuewuhkust.github.io/AniPortraitGAN

    Regulation of Type 2 Immunity in Myocardial Infarction

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    Type 2 immunity participates in the pathogeneses of helminth infection and allergic diseases. Emerging evidence indicates that the components of type 2 immunity are also involved in maintaining metabolic hemostasis and facilitating the healing process after tissue injury. Numerous preclinical studies have suggested regulation of type 2 immunity-related cytokines, such as interleukin-4, -13, and -33, and cell types, such as M2 macrophages, mast cells, and eosinophils, affects cardiac functions after myocardial infarction (MI), providing new insights into the importance of immune modulation in the infarcted heart. This review provides an overview of the functions of these cytokines and cells in the setting of MI as well as their potential to predict the severity and prognosis of MI

    Long-distance transport of sucrose in source leaves promotes sink root growth by the EIN3-SUC2 module

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    In most plants, sucrose, a major storage sugar, is transported into sink organs to support their growth. This key physiological process is dependent on the function of sucrose transporters. Sucrose export from source tissues is predominantly controlled through the activity of SUCROSE TRANSPORTER 2 (SUC2), required for the loading of sucrose into the phloem of Arabidopsis plants. However, how SUC2 activity is controlled to support root growth remains unclear. Glucose is perceived via the function of HEXOKINASE 1 (HXK1), the only known nuclear glucose sensor. HXK1 negatively regulates the stability of ETHYLENE-INSENSITIVE3 (EIN3), a key ethylene/glucose interaction component. Here we show that HXK1 functions upstream of EIN3 in the regulation of root sink growth mediated by glucose signaling. Furthermore, the transcription factor EIN3 directly inhibits SUC2 activity by binding to the SUC2 promoter, regulating glucose signaling linked to root sink growth. We demonstrate that these molecular components form a HXK1-EIN3-SUC2 module integral to the control of root sink growth. Also, we demonstrate that with increasing age, the HXK1-EIN3-SUC2 module promotes sucrose phloem loading in source tissues thereby elevating sucrose levels in sink roots. As a result, glucose signaling mediated-sink root growth is facilitated. Our findings thus establish a direct molecular link between the HXK1-EIN3-SUC2 module, the source-to sink transport of sucrose and root growth

    The LEGUE Input Catalogue for Dark Night Observing in the LAMOST Pilot Survey

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    We outline the design of the dark nights portion of the LAMOST Pilot Survey, which began observations in October 2011. In particular, we focus on Milky Way stellar candidates that are targeted for the LEGUE (LAMOST Experiment for Galactic Understanding and Exploration) survey. We discuss the regions of sky in which spectroscopic candidates were selected, and the motivations for selecting each of these sky areas. Some limitations due to the unique design of the telescope are discussed, including the requirement that a bright (V < 8) star be placed at the center of each plate for wavefront sensing and active optics corrections. The target selection categories and scientific goals motivating them are briefly discussed, followed by a detailed overview of how these selection functions were realized. We illustrate the difference between the overall input catalog - Sloan Digital Sky Survey (SDSS) photometry - and the final targets selected for LAMOST observation.Comment: 11 pages, 7 figures, accepted for publication in RA
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