95 research outputs found
Do political connections foster or hamper firm environmental investment?
Extant studies of environmental investment determinants have
not distinguished between different types of political connections.
This study tries to close this gap by employing an extensive dataset
based on the four-yearly Chinese Private Enterprises Survey
conducted between 2006 and 2012. The central question in this
paper asks whether different political connections (ascribed vs.
achieved) are fostering or hindering environmental protection
expenditures in private enterprises. The results show that
achieved political connections serve as binds of promoting firm
environmental investment while ascribed political connections act
as buffers, hampering firm environmental expenditures. The moderating
roles of environmental regulation and innovation capability
demonstrate heterogeneous effects: environmental regulation
stringency strengthens the positive impact of achieved political
connections only. In contrast, innovation capability enhances the
negative impact of ascribed political connections
From Indoor To Outdoor: Unsupervised Domain Adaptive Gait Recognition
Gait recognition is an important AI task, which has been progressed rapidly
with the development of deep learning. However, existing learning based gait
recognition methods mainly focus on the single domain, especially the
constrained laboratory environment. In this paper, we study a new problem of
unsupervised domain adaptive gait recognition (UDA-GR), that learns a gait
identifier with supervised labels from the indoor scenes (source domain), and
is applied to the outdoor wild scenes (target domain). For this purpose, we
develop an uncertainty estimation and regularization based UDA-GR method.
Specifically, we investigate the characteristic of gaits in the indoor and
outdoor scenes, for estimating the gait sample uncertainty, which is used in
the unsupervised fine-tuning on the target domain to alleviate the noises of
the pseudo labels. We also establish a new benchmark for the proposed problem,
experimental results on which show the effectiveness of the proposed method. We
will release the benchmark and source code in this work to the public
A Benchmark of Video-Based Clothes-Changing Person Re-Identification
Person re-identification (Re-ID) is a classical computer vision task and has
achieved great progress so far. Recently, long-term Re-ID with clothes-changing
has attracted increasing attention. However, existing methods mainly focus on
image-based setting, where richer temporal information is overlooked. In this
paper, we focus on the relatively new yet practical problem of clothes-changing
video-based person re-identification (CCVReID), which is less studied. We
systematically study this problem by simultaneously considering the challenge
of the clothes inconsistency issue and the temporal information contained in
the video sequence for the person Re-ID problem. Based on this, we develop a
two-branch confidence-aware re-ranking framework for handling the CCVReID
problem. The proposed framework integrates two branches that consider both the
classical appearance features and cloth-free gait features through a
confidence-guided re-ranking strategy. This method provides the baseline method
for further studies. Also, we build two new benchmark datasets for CCVReID
problem, including a large-scale synthetic video dataset and a real-world one,
both containing human sequences with various clothing changes. We will release
the benchmark and code in this work to the public
New ionic dinuclear Ir(III) Schiff base complexes with aggregation-induced phosphorescent emission (AIPE)
Two new ionic dinuclear Ir(III) Schiff base complexes which are straightforward to synthesise have luminescence quantum yields as high as 37% in neat films. These are the first examples of dinuclear ionic Ir(III) complexes that display aggregation-induced phosphorescent emission (AIPE)
Towards increased concentration sensitivity for continuous wave EPR investigations of spin-labeled biological macromolecules at high fields
This work was performed at the National High Magnetic Field Laboratory (NHMFL), which is supported by the National Science Foundation (DMR-1157490) and the State of Florida. L.S. acknowledges support from the National Institutes of Health (AI091693) and the NHMFL User Collaboration Grants Program (Award No. 5080). G.E.F. acknowledges support from the National Science Foundation (MCB-1329467) and the National Institutes of Health (GM105409 and S10RR031603). S.H. acknowledges support from the National Science Foundation (DMR-1309463). J.M.E acknowledges support from the National Science Foundation (DGE-0802270).High-field, high-frequency electron paramagnetic resonance (EPR) spectroscopy at W- (∼95 GHz) and D-band (∼140 GHz) is important for investigating the conformational dynamics of flexible biological macromolecules because this frequency range has increased spectral sensitivity to nitroxide motion over the 100 ps to 2 ns regime. However, low concentration sensitivity remains a roadblock for studying aqueous samples at high magnetic fields. Here, we examine the sensitivity of a non-resonant thin-layer cylindrical sample holder, coupled to a quasi-optical induction-mode W-band EPR spectrometer (HiPER), for continuous wave (CW) EPR analyses of: (i) the aqueous nitroxide standard, TEMPO; (ii) the unstructured to α-helical transition of a model IDP protein; and (iii) the base-stacking transition in a kink-turn motif of a large 232 nt RNA. For sample volumes of ∼50 μL, concentration sensitivities of 2-20 μM were achieved, representing a ∼10-fold enhancement compared to a cylindrical TE011 resonator on a commercial Bruker W-band spectrometer. These results therefore highlight the sensitivity of the thin-layer sample holders employed in HiPER for spin-labeling studies of biological macromolecules at high fields, where applications can extend to other systems that are facilitated by the modest sample volumes and ease of sample loading and geometry.PostprintPeer reviewe
HIV-1 Broadly Neutralizing Antibody Extracts Its Epitope from a Kinked gp41 Ectodomain Region on the Viral Membrane
SummaryAlthough rarely elicited during natural human infection, the most broadly neutralizing antibodies (BNAbs) against diverse human immunodeficiency virus (HIV)-1 strains target the membrane-proximal ectodomain region (MPER) of viral gp41. To gain insight into MPER antigenicity, immunogenicity, and viral function, we studied its structure in the lipid environment by a combination of nuclear magnetic resonance (NMR), electron paramagnetic resonance (EPR), and surface plasmon resonance (SPR) techniques. The analyses revealed a tilted N-terminal α helix (aa 664–672) connected via a short hinge to a flat C-terminal helical segment (675–683). This metastable L-shaped structure is immersed in viral membrane and, therefore, less accessible to immune attack. Nonetheless, the 4E10 BNAb extracts buried W672 and F673 after initial encounter with the surface-embedded MPER. The data suggest how BNAbs may perturb tryptophan residue-associated viral fusion involving the mobile N-terminal MPER segment and, given conservation of MPER sequences in HIV-1, HIV-2, and SIV, have important implications for structure-guided vaccine design
The Chemistry of Phospholipid Binding by the Saccharomyces cerevisiae Phosphatidylinositol Transfer Protein Sec14p as Determined by EPR Spectroscopy
The major yeast phosphatidylinositol/phosphatidylcholine transfer protein Sec14p is the founding member of a large eukaryotic protein superfamily. Functional analyses indicate Sec14p integrates phospholipid metabolism with the membrane trafficking activity of yeast Golgi membranes. In this regard, the ability of Sec14p to rapidly exchange bound phospholipid with phospholipid monomers that reside in stable membrane bilayers is considered to be important for Sec14p function in cells. How Sec14p-like proteins bind phospholipids remains unclear. Herein, we describe the application of EPR spectroscopy to probe the local dynamics and the electrostatic microenvironment of phosphatidylcholine (PtdCho) bound by Sec14p in a soluble protein-PtdCho complex. We demonstrate that PtdCho movement within the Sec14p binding pocket is both anisotropic and highly restricted and that the C5 region of the sn-2 acyl chain of bound PtdCho is highly shielded from solvent, whereas the distal region of that same acyl chain is more accessible. Finally, high field EPR reports on a heterogeneous polarity profile experienced by a phospholipid bound to Sec14p. Taken together, the data suggest a headgroup-out orientation of Sec14p-bound PtdCho. The data further suggest that the Sec14p phospholipid binding pocket provides a polarity gradient that we propose is a primary thermodynamic factor that powers the ability of Sec14p to abstract a phospholipid from a membrane bilayer
Analyses of a chromosome-scale genome assembly reveal the origin and evolution of cultivated chrysanthemum
DATA AVAILABILITY : The raw sequencing data generated in this study have been deposited
in the NCBI under accession PRJNA796762 and PRJNA895586 The
chloroplast andmitochondrial genome were also available at GenBank
under the accession number OP104251 and OP104742 respectively.
The assembled genome sequences and annotations are available at
Figshare [https://doi.org/10.6084/m9.figshare.21655364.v2]. The Arabidopsis
ABCE and chrysanthemum CYC2 genes were used as query
sequences for gene family identification, which are available at Figshare
[https://doi.org/10.6084/m9.figshare.21610305]. Source data are
provided with this paper.Chrysanthemum (Chrysanthemum morifolium Ramat.) is a globally important
ornamental plant with great economic, cultural, and symbolic value. However,
research on chrysanthemum is challenging due to its complex genetic background.
Here, we report a near-complete assembly and annotation for
C. morifolium comprising 27 pseudochromosomes (8.15 Gb; scaffold N50 of
303.69Mb). Comparative and evolutionary analyses reveal a whole-genome
triplication (WGT) event shared by Chrysanthemum species approximately 6
million years ago (Mya) and the possible lineage-specific polyploidization of
C. morifolium approximately 3 Mya. Multilevel evidence suggests that
C. morifolium is likely a segmental allopolyploid. Furthermore, a combination
of genomics and transcriptomics approaches demonstrate the C. morifolium
genome can be used to identify genes underlying key ornamental traits. Phylogenetic
analysis of CmCCD4a traces the flower colour breeding history of
cultivated chrysanthemum. Genomic resources generated from this study
could help to accelerate chrysanthemum genetic improvement.The National Natural Science Foundation of China, the Natural Science Fund of Jiangsu Province, China Agriculture Research System, the National Key Research and Development Program of China, the “JBGS” Project of Seed Industry Revitalisation in Jiangsu Province, the European Union’s Horizon 2020 research and innovation program from European Research Council, the Methusalem funding from Ghent University, and a project funded by the Priority Academic Program Development of Jiangsu Higher Education Institution.https://www.nature.com/ncomms/am2024BiochemistryGeneticsMicrobiology and Plant PathologySDG-15:Life on lan
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