Preliminary Structural Data Revealed That the SARS-CoV-2 B.1.617 Variant's RBD Binds to ACE2 Receptor Stronger Than the Wild Type to Enhance the Infectivity

The evolution of new SARS-CoV-2 variants around the globe has made the COVID-19 pandemic more worrisome, further pressuring the health care system and immunity. Novel variations that are unique to the receptor-binding motif (RBM) of the receptor-binding domain (RBD) spike glycoprotein, i. e. L452R-E484Q, may play a different role in the B.1.617 (also known as G/452R.V3) variant's pathogenicity and better survival compared to the wild type. Therefore, a thorough analysis is needed to understand the impact of these mutations on binding with host receptor (RBD) and to guide new therapeutics development. In this study, we used structural and biomolecular simulation techniques to explore the impact of specific mutations (L452R-E484Q) in the B.1.617 variant on the binding of RBD to the host receptor ACE2. Our analysis revealed that the B.1.617 variant possesses different dynamic behaviours by altering dynamic-stability, residual flexibility and structural compactness. Moreover, the new variant had altered the bonding network and structural-dynamics properties significantly. MM/GBSA technique was used, which further established the binding differences between the wild type and B.1.617 variant. In conclusion, this study provides a strong impetus to develop novel drugs against the new SARS-CoV-2 variants.     

西湖凹陷中部西斜坡地区超压成因机制

沉积盆地超压成因研究已取得了重要进展，关于超压主要成因的认识也发生了重要变化，以往一些被普遍认为属于典型不均衡压实成因的超压已被部分或完全否定，生烃作用作为超压成因的普遍性得到愈来愈多的证实。西湖凹陷多个构造带的不同层位均发育超压，目前认为超压的形成仍然离不开不均衡压实（欠压实作用）的贡献。根据异常压力形成的基本地质条件和异常压力产生的地质、地球物理效应两方面因素，利用测井曲线组合分析法、鲍尔斯法（加载-卸载曲线法）、声波速度-密度交会图法、孔隙度对比法、压力计算反推法以及综合分析法系统解剖分析了西湖凹陷中部西斜坡地区平湖组不同岩性异常压力成因。研究结果表明：西湖凹陷中部西斜坡泥岩中烃源岩超压主要为自源生烃增压，非烃源岩超压为邻源压力传导成因。储层中至少存在常压-超压型和常压-超压-常压型两种压力结构类型，异常压力自南向北顶界面逐渐变深，主要为油气在生烃增压驱动下向储层运移过程中的压力传导所致。     

Strategic use of storage: The impact of carbon policy,resource availability,and technology efficiency on a renewable-thermal power system

Concerns about climate change have spurred governments to reduce carbon emissions by supporting adoption of renewable energy (RE) technologies. Due to the intermittent and location-specific nature of RE technologies, energy storage has become important because it could be used to smooth out temporal disparities in residual demand. Thus, carbon policy has made storage-enabled RE generation more critical to the power sector, and this enhanced position could be exploited by firms to exert market power. Using an equilibrium model, we examine the implications of policy interventions and technological change on the marginal value of energy storage in a power market with RE and thermal generation. In particular, we specify the market conditions under which RE producers with storage strategically shift deployment of their resource to the off-peak period and outline its implications for the marginal value of RE storage. Moreover, we find that even price-taking RE producers may actually increase off-peak RE production as storage efficiency increases. Consequently, the RE producer's profit decreases with storage efficiency, which conflicts with the social objective of improving storage efficiency. These private and social incentives can be better aligned via a carbon tax, however. Hence, our results may inform the regulatory process governing market design of a power sector with increasing capacities of RE generation and storage.     

Agreement matters: OPEC announcement effects on WTI term structure

We investigate the relationships between different types of OPEC announcements and term structure variables (level, slope and curvature) for WTI crude oil futures. We find that agreements to increase (decrease) production are positively (negatively) associated with changes in oil price levels in futures markets. This finding is consistent with recent research. For the first time in the literature, we evaluate announcements which signify ‘no change’ in production quotas. In particular, a ‘no change’ announcement may be due to a unanimous agreement to maintain quotas unchanged, or it may be due to a failure to agree on a change in quotas. We find the term structure effects (on slope and curvature) of the two types of announcement to be statistically significantly different from each other. Our results suggest that markets are more optimistic following agreements to maintain production, and more cautious following a failure to agree.     

Seeing the bigger picture: Conditions that influence effective engagement of project executives with visuals

This exploratory study provides an influence diagram that shows the network of conditions that influence the use of visuals to effectively engage executives. The diagram was developed from the experiences of project managers and executives elicited through twenty-four semi-structured interviews. Twenty-nine conditions are found to influence the use of visuals to effectively engage executives. These are grouped into four categories: the executive's disposition to the use of visuals; the organisational conditions to create visuals; the project manager's understanding of the executive's information needs; and the executive's and project manager's appreciation of the benefits of using visuals. The study's results highlight that while the interviewed executives had a predisposition to the use of visuals as they are generally time-poor, capability to create visuals to support executive engagement was not widespread. Practical contributions include disclosing the criticality of organisational support for creating visuals and the vulnerability of executives in making project decisions.     

Emerging strategy recognition in agile portfolios

Agile practices become increasingly popular for projects and project portfolios offering firms a higher flexibility to adapt to dynamic environments. This study investigates the antecedents and consequences of agile practices' relevance for strategy formulation in project portfolio management processes. Building on complex adaptive systems theory, we hypothesize a positive relationship between agile capabilities and emerging strategy initiatives and eventually portfolio success. Agile capabilities refer to both the project portfolio organization's intensity of and competence in applying agile practices. Using a sample of 135 portfolios and multiple informants for each portfolio, the results support entrepreneurial orientation and voice behavior as antecedents for agile capabilities. Furthermore, the findings support an agile portfolio's positive relationship with emergence recognition and overall portfolio success. The findings contribute to the literature by identifying two significant antecedents of agile capabilities as well as empirically demonstrating the positive relationship between agile portfolios and emerging strategy recognition. For practitioners, the study encourages the application of agile practices by stressing the general positive influence of agile capabilities and underlines entrepreneurial orientation and voice behavior as important methods of empowerment for agile portfolio processes.     

Fabrication and optimization of polypyrrole/cerium oxide/glassy carbon sensing platform for the electrochemical detection of flupirtine

Journal of Applied Electrochemistry - In spite of single nanomaterials, nanocomposites have come to be the superior modifying materials for electrochemical sensing. Herein, the highly...