125 research outputs found

    Cdc42 Effector Protein 3 Interacts With Cdc42 in Regulating Xenopus Somite Segmentation

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    Somitogenesis is a critical process during vertebrate development that establishes the segmented body plan and gives rise to the vertebra, skeletal muscles, and dermis. While segmentation clock and wave front mechanisms have been elucidated to control the size and time of somite formation, regulation of the segmentation process that physically separates somites is not understood in detail. Here, we identified a cytoskeletal player, Cdc42 effector protein 3 (Cdc42ep3, CEP3) that is required for somite segmentation in Xenopus embryos. CEP3 is specifically expressed in somite tissue during somite segmentation. Loss-of-function experiments showed that CEP3 is not required for the specification of paraxial mesoderm, nor the differentiation of muscle cells, but is required for the segmentation process. Live imaging analysis further revealed that CEP3 is required for cell shape changes and alignment during somitogenesis. When CEP3 was knocked down, somitic cells did not elongate efficiently along the mediolateral axis and failed to undertake the 90° rotation. As a result, cells remained in a continuous sheet without an apparent segmentation cleft. CEP3 likely interacts with Cdc42 during this process, and both increased and decreased Cdc42 activity led to defective somite segmentation. Segmentation defects caused by Cdc42 knockdown can be partially rescued by the overexpression of CEP3. Conversely, loss of CEP3 resulted in the maintenance of high levels of Cdc42 activity at the cell membrane, which is normally reduced during and after somite segmentation. These results suggest that there is a feedback regulation between Cdc42 and CEP3 during somite segmentation and the activity of Cdc42 needs to be fine-tuned to control the coordinated cell shape changes and movement required for somite segmentation

    Consumers’ preferences for micronutrient strategies in China : a comparison between folic acid supplementation and folate biofortification

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    AbstractObjectiveDespite public health efforts, folate deficiency is still largely prevalent in poor, rural populations and continues to cause a large burden of disease. The present paper determines and compares consumer preferences for two folate strategies: folic acid supplementationv.folate biofortification, i.e. the enhancement of the folate content in staple crops.DesignExperimental auctions with non-repeated information rounds are applied to rice in order to obtain willingness-to-pay for folate products. Thereby, GM or non-GM folate-biofortified rice (FBR) is auctioned together with rice that is supplemented with free folic acid pills (FAR).SettingShanxi Province (China) as a high-risk region of folate deficiency.SubjectsOne hundred and twenty-six women of childbearing age, divided into a school (n60) and market sample (n66).ResultsDespite differences according to the targeted sample, a general preference for folate biofortification is observed, regardless of the applied breeding technology. Premiums vary between 33·9 % (GM FBR), 36·5 % (non-GM FBR) and 19·0 % (FAR). Zero bidding behaviour as well as the product choice question, respectively, support and validate these findings. The targeted sample, the timing of the auction, the intention to consume GM food and the responsibility for rice purchases are considered key determinants of product choice. A novel ex-post negative valuation procedure shows low consistency in zero bidding.ConclusionsWhile the low attractiveness of FAR provides an additional argument for the limited effectiveness of past folic acid supplementation programmes, the positive reactions towards GM FBR further support its potential as a possible complementary micronutrient intervention.</jats:sec

    Review of Bats and SARS

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    TOC Summary: The discovery of SARS-like coronaviruses in horseshoe bats highlights the possibility of future outbreaks caused by different coronaviruses of bat origin

    Smart power consumption in energy digital economy: A perspective of the value co-creation mechanism

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    Residential load is one of the important components of the seasonal peak load of the power grid, and it is increasing each year, with a huge demand response potential. With the development of the energy digital economy, the demand response of the new power system shows the characteristics of multi-stakeholder participation. The development mode based on the value co-creation has become a prominent support for market-oriented reform, and the need for the promotion of smart electricity use is increasingly prominent. In order to realize the in-depth exploration of residents’ demand response potential and the sustainable development of “value co-creation” of smart electricity consumption with the participation of multi-stakeholders, this study adopts both the social network analysis method and the counterfactual analysis approach to reveal the general characteristics of agents promoting the residents to participate in the value co-creation of smart electricity positively. The results show that 1) for social network, both the absolute resource advantage and the structural hole have obvious positive guidance on the agent; however, the incentive effect of the relative resource advantage is not significant; 2) for individual nodes , the role positioning of each agent has obvious guiding function for realizing the value co-creation; and 3) for interrelationship among main agents, the functional relationship has a significant degree of interdependence

    Differential stepwise evolution of SARS coronavirus functional proteins in different host species

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    <p>Abstract</p> <p>Background</p> <p>SARS coronavirus (SARS-CoV) was identified as the etiological agent of SARS, and extensive investigations indicated that it originated from an animal source (probably bats) and was recently introduced into the human population via wildlife animals from wet markets in southern China. Previous studies revealed that the spike (S) protein of SARS had experienced adaptive evolution, but whether other functional proteins of SARS have undergone adaptive evolution is not known.</p> <p>Results</p> <p>We employed several methods to investigate selective pressure among different SARS-CoV groups representing different epidemic periods and hosts. Our results suggest that most functional proteins of SARS-CoV have experienced a stepwise adaptive evolutionary pathway. Similar to previous studies, the spike protein underwent strong positive selection in the early and middle phases, and became stabilized in the late phase. In addition, the replicase experienced positive selection only in human patients, whereas assembly proteins experienced positive selection mainly in the middle and late phases. No positive selection was found in any proteins of bat SARS-like-CoV. Furthermore, specific amino acid sites that may be the targets of positive selection in each group are identified.</p> <p>Conclusion</p> <p>This extensive evolutionary analysis revealed the stepwise evolution of different functional proteins of SARS-CoVs at different epidemic stages and different hosts. These results support the hypothesis that SARS-CoV originated from bats and that the spill over into civets and humans were more recent events.</p

    Engineered soluble ACE2 receptor: Responding to change with change

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    SARS coronavirus 2 (SARS-CoV-2) invades the human body by binding to major receptors such as ACE2 via its S-spike protein, so the interaction of receptor-binding sites has been a hot topic in the development of coronavirus drugs. At present, the clinical progress in monoclonal antibody therapy that occurred early in the pandemic is gradually showing signs of slowing. While recombinant soluble ACE2, as an alternative therapy, has been modified by many engineering methods, both the safety and functional aspects are approaching maturity, and this therapy shows great potential for broadly neutralizing coronaviruses, but its progress in clinical development remains stalled. Therefore, there are still several key problems to be considered and solved for recombinant soluble ACE2 to be approved as a clinical treatment as soon as possible

    Comparing the LC-MS phenolic acids profiles of aeven different varieties of brown rice (Oryza sativa L.)

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    Brown rice, an important material of whole-grain food, is increasingly popular for its health benefits. Thus, seven varieties of brown rice from southern China were analyzed in this study, concerning the free and bound phenolic compounds in the extract. The phenolic profiles of different brown rice were obtained and compared by the combination of HPLC and LC-MS analysis, in which eleven phenolic acids were identified. It was indicated that the total phenolic contents of different brown rice varied from 92.32 to 196.54 mg of gallic acid equivalent (GAE)/100 g DW. Ferulic acid and p-coumaric acid, free and bound, dominated within the phenolic acids. To be mentioned, the total phenols of Luotiangongmi (a kind of red rice) were significantly higher than the other six varieties. The high phenolic content of brown rice can further guide us to explore the functional properties of the crops
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