251 research outputs found
Does signing auditors’ communist party membership shape audit quality? Evidence from China
In this article, we investigate the effect of signing auditors’ communist
party membership on audit quality. Relying on a sample of
Chinese listed firms from the period 2001 to 2019, we find that firms
with signing auditors who have communist party membership conduct
less earnings management, indicating that signing auditors with
party membership provide high level of audit quality. Moreover, the
above relationship is more pronounced in small audit firms. We also
find that firms who are audited by signing auditors with party status
have lower likelihood of financial statements and loss avoidance.
Further analyses suggest that signing auditors with party status can
earn audit fee premium. The positive relationship between signing
auditors with party membership and audit quality is more pronounced
in non-specialists auditors and high client importance
Heterologous protein display on the cell surface of lactic acid bacteria mediated by the s-layer protein
<p>Abstract</p> <p>Background</p> <p>Previous studies have revealed that the C-terminal region of the S-layer protein from <it>Lactobacillus </it>is responsible for the cell wall anchoring, which provide an approach for targeting heterologous proteins to the cell wall of lactic acid bacteria (LAB). In this study, we developed a new surface display system in lactic acid bacteria with the C-terminal region of S-layer protein SlpB of <it>Lactobacillus crispatus </it>K2-4-3 isolated from chicken intestine.</p> <p>Results</p> <p>Multiple sequence alignment revealed that the C-terminal region (LcsB) of <it>Lb. crispatus </it>K2-4-3 SlpB had a high similarity with the cell wall binding domains S<sub>A </sub>and CbsA of <it>Lactobacillus acidophilus </it>and <it>Lb. crispatus</it>. To evaluate the potential application as an anchoring protein, the green fluorescent protein (GFP) or beta-galactosidase (Gal) was fused to the N-terminus of the LcsB region, and the fused proteins were successfully produced in <it>Escherichia coli</it>, respectively. After mixing them with the non-genetically modified lactic acid bacteria cells, the fused GFP-LcsB and Gal-LcsB were functionally associated with the cell surface of various lactic acid bacteria tested. In addition, the binding capacity could be improved by SDS pretreatment. Moreover, both of the fused proteins could simultaneously bind to the surface of a single cell. Furthermore, when the fused DNA fragment of <it>gfp:lcsB </it>was inserted into the <it>Lactococcus lactis </it>expression vector pSec:Leiss:Nuc, the GFP could not be secreted into the medium under the control of the <it>nisA </it>promoter. Western blot, in-gel fluorescence assay, immunofluorescence microscopy and SDS sensitivity analysis confirmed that the GFP was successfully expressed onto the cell surface of <it>L. lactis </it>with the aid of the LcsB anchor.</p> <p>Conclusion</p> <p>The LcsB region can be used as a functional scaffold to target the heterologous proteins to the cell surfaces of lactic acid bacteria <it>in vitro </it>and <it>in vivo</it>, and has also the potential for biotechnological application.</p
Industry-finance integration activities is beneficial to the improvement of business performance of fishery companies—Based on DEA-CCR Model and DEA-Malmquist Model
Fisheries are an essential component of the national economy. The evaluation of fishery enterprises' business performance helps reveal the fishery industry's operating efficiency and serve the fishery economy's sustainable and high-quality development. This study used the data of fishery companies with industry-finance integration on the stock market from 2012-2021 and conducted a comparative study on the business performance of fishery companies with industry-finance integration on the stock market based on the DEA-CCR model and DEA- Malmquist index method. Two main results were revealed (i) the integration of industry and finance was an effective means to improve business performance, and the financial gains from the integration of industry and finance by listed fishery companies improve the overall efficiency and total factor productivity (TFP) of enterprises. (ii) The average TFP of listed fishery companies in China is declining, and technological decline is the main reason for the decline in TFP
Acclimation of photosystem II to high temperature in two Wedelia species from different geographical origins: implications for biological invasions upon global warming
More intense, more frequent, and longer heat waves are expected in the future due to global warming, which could have dramatic ecological impacts. However, few studies have involved invasive species. The aims of this study were to examine the effect of extreme heating (40/35°C for 30d) on the growth and photosynthesis of an alien invasive species Wedelia trilobata and its indigenous congener (Wedelia chinensis) in South China, and to determine the development of this invasive species and its potential adaptive mechanism. In comparison with W. chinensis, W. trilobata suffered less inhibition of the relative growth rate (RGR) and biomass production due to high temperature, which was consistent with the changes of photosystem II (PSII) activity and net photosynthetic rate (Pn). High temperature caused a partial inhibition of PSII, but the adverse effect was more severe in W. chinensis. Measurement of the minimum fluorescence (Fo) versus temperature curves showed that W. trilobata had a higher inflexion temperature of Fo (Ti), indicating greater thermostability of the photosynthetic apparatus. Moreover, comparisons of absorbed light energy partitioning revealed that W. trilobata increased xanthophyll-dependent thermal dissipation (ΦNPQ) under high temperature, while retaining the higher fraction of absorbed light allocated to photochemistry (ΦPSII) relative to W. chinensis. The results suggest that the invasive W. trilobata has a high thermostability of its photosynthetic apparatus and an effective regulating mechanism in energy partitioning of PSII complexes to minimize potential damage and to retain greater capability for carbon assimilation. These factors confer greater heat stress tolerance compared with the native species. Therefore, the invasive W. trilobata may become more aggressive with the increasingly extreme heat climates
Study on Synthesis and Photocatalytic Activity of Porous Titania Nanotubes
Using the common natural cellulose substance (filter paper) and triblock copolymer (Pluronic P123) micelles as dual templates, porous titania nanotubes with enhanced photocatalytic activity have been successfully synthesized through sol-gel methods. Firstly, P123 micelles were adsorbed onto the surfaces of cellulose nanofibers of filter paper, followed by hydrolysis and condensation of tetrabutyl titanate around these micelles to form titania layer. After calcination to remove the organic templates, hierarchical titania nanotubes with pores in the walls were obtained. The sample was characterized by X-ray diffraction pattern (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), nitrogen adsorption/desorption, Fourier Transform Infrared Spectroscopy (FT-IR), Ultraviolet-Visible Diffuse Reflectance Spectroscopy (UV-Vis DRS), and X-ray photoelectron spectroscopy (XPS). As compared with commercial P25 catalyst, the porous titania nanotubes prepared by this method displayed significantly enhanced photocatalytic activity for degrading methyl orange under UV irradiation. Within 10 minutes, the porous titania nanotubes are able to degrade over 70% of the original MO, while the value for the commercial Degussa P25 is only about 33%
Disentangling the effects of vapor pressure deficit on northern terrestrial vegetation productivity
The impact of atmospheric vapor pressure deficit (VPD) on plant photosynthesis has long been acknowledged, but large interactions with air temperature (T) and soil moisture (SM) still hinder a complete understanding of the influence of VPD on vegetation production across various climate zones. Here, we found a diverging response of productivity to VPD in the Northern Hemisphere by excluding interactive effects of VPD with T and SM. The interactions between VPD and T/SM not only offset the potential positive impact of warming on vegetation productivity but also amplifies the negative effect of soil drying. Notably, for high-latitude ecosystems, there occurs a pronounced shift in vegetation productivity\u27s response to VPD during the growing season when VPD surpasses a threshold of 3.5 to 4.0 hectopascals. These results yield previously unknown insights into the role of VPD in terrestrial ecosystems and enhance our comprehension of the terrestrial carbon cycle\u27s response to global warming
Case report: Reversible splenial lesion syndrome caused by diquat poisoning
Diquat (DQ), chemically known as 1,1 ‘-ethylene-2,2’ -bipyridine, is a non-selective herbicide for leaf removal and drying. It has toxic effects on central nervous system cells, and toxic neurological lesions include axonal degeneration and pontine myelolysis. At the same time, DQ can also affect the activity of dopaminergic nerve cells through oxidative stress, causing degeneration and reducing dopamine uptake. With the increasing application of DQ in agricultural production, the clinical reports of neurotoxicity caused by acute DQ poisoning are also increasing. At present, DQ rapid-phase-related toxic encephalopathy mainly involves the pons, midbrain, basal ganglia, thalamus and other brain regions. However, this case is unusual in that the lesion mainly involved the splenium of the corpus callosum. It is also the first time to be reported
The chemical profiling of Salvia plebeia during different growth periods and the biosynthesis of its main flavonoids ingredients
Salvia plebeia (Lamiaceae) is a valuable medicinal plant widely distributed across Asia and Oceania. However, the composition and accumulation patterns of its active ingredients in different organs during the growth and their biosynthetic mechanism remain unknown. Therefore, we conducted metabolite profiling, transcriptomic analysis, and biological functional verification to explore the distribution, accumulation, and biosynthesis mechanisms of flavonoids in S. plebeia. We identified 70 metabolites including 46 flavonoids, 16 phenolic acids, seven terpenoids, and one organic acid, of which 21 were previously unreported in S. plebeia. Combining metabolomic-transcriptomic analysis and biological functional verification, we identified the key genes involved in biosynthesis of its main active ingredients, hispidulin and homoplantaginin, including SpPAL, SpC4H, Sp4CL2, Sp4CL5, SpCHS1, SpCHI, SpFNS, SpF6H1, SpF6OMT1, SpF6OMT2, SpUGT1, SpUGT2, and SpUGT3. Using the identified genes, we reconstructed the hispidulin and homoplantaginin biosynthesis pathways in Escherichia coli, and obtained a yield of 5.33 and 3.86 mg/L for hispidulin and homoplantaginin, respectively. Our findings provide valuable insights into the changes in chemical components in different organs of S. plebeia during different growth and harvest stages and establishes a foundation for identifying and synthesizing its active components
A gold-nanoparticle stoppered [2]rotaxane
The construction of molecular machines has captured the imagination of scientists for decades. Despite significant progress in the synthesis and studies of the properties of small-molecule components (smaller than 2-5 kilo Dalton), challenges regarding the incorporation of molecular components into real devices are still eminent. Nano-sized molecular machines operate the complex biological machinery of life, and the idea of mimicking the amazing functions using artificial nano-structures is intriguing. Both in small-molecule molecular machine components and in many naturally occurring molecular machines, mechanically interlocked molecules and structures are key functional components. In this work, we describe our initial efforts to interface mechanically-interlocked molecules and gold-nanoparticles (AuNPs); the molecular wire connecting the AuNPs is covered in an insulating rotaxane-layer, thus mimicking the macroscopic design of a copper wire. Taking advantage of recent progress in the preparation of supramolecular complexes of the cucurbit[7]uril (CB[7]) macrocycle, we have prepared a bis-thiol functionalised pseudo-rotaxane that enables us to prepare a AuNP-stoppered [2]rotaxane in water. The pseudo-rotaxane is held together extremely tightly (Ka > 1013 M-1), Ka being the association constant. We have studied the solution and gas phase guest-host chemistry using NMR spectroscopy, mass spectroscopy, and electrochemistry. The bis-thiol functionalised pseudo-rotaxane holds further a ferrocene unit in the centre of the rotaxane; this ferrocene unit enables us to address the system in detail with and without CB[7] and AuNPs using electrochemical methods
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