In this paper, a new (
3
+
1
)-dimensional generalized KP (gKP) equation is presented, and two classes of lump solutions, rationally localized in all directions in the space, to the dimensionally ...reduced cases in (
2
+
1
)-dimensions are derived as well. The proposed method in this work is based on a Hirota bilinear differential equation, which implies that we can build the lump solutions to the presented reduced gKP equation from positive quadratic function solutions to the aforementioned bilinear equation. Moreover, there are totally six free parameters in the resulting lump solutions, so that we can get the sufficient and necessary conditions guaranteeing analyticity and rational localization of the solutions by using these six free parameters. In the meantime, two special cases are plotted as illustrative examples and some contour plots with different determinant values are given to show that the corresponding lump solution tends to zero when the determinant approaches zero.
We examine the volatility spillovers among various industries during the COVID-19 pandemic period. We measure volatility spillovers by defining the volatility of each sector in the S&P 500 index and ...implement a static and rolling-window analysis following the Diebold and Yilmaz (2012) approach. We find that the pandemic enhanced volatility spillovers, which reveals the financial contagion effects on the US stock market. Second, there were sudden, large changes in the dynamic volatility spillovers on Black Monday (March 9, 2020), much of it due to the energy sector shock. These findings have important implications for portfolio managers and policymakers.
•We examine the volatility spillovers for various industries in the COVID-19 pandemic.•We implement a static and rolling-window analysis.•We find that the pandemic enhanced volatility spillovers.•We also find that large changes in the dynamic volatility spillovers on Black Monday.•The energy sector shock is the main cause of Black Monday.
Are green investments decoupled from the dirty investment such as the fossil fuel markets? We address this issue by extending the literature on environmental, social, and governance (ESG) assets by ...examining the dynamic relationship between fossil fuels and digital ESG assets proxied by green cryptocurrencies using the TVP-VAR(Time-varying parameter vector auto regression) spillover framework. Furthermore, we analyze the hedging attributes of green cryptocurrencies and fossil fuels in a minimum connectedness framework. The main findings are as follows: First, green cryptocurrencies are the main shock transmitters in all asset systems. Second, the dynamic connectedness between green cryptocurrencies and fossil fuels increased during the COVID-19 and Russia-Ukraine conflicts. Third, green cryptocurrencies have shown considerable hedging effectiveness against the fossil fuels. Our study has important implications for investors, regulators, and policy makers, such as shifting to green cryptocurrencies, regulation of carbon footprint, and promoting eco-friendly assets.
We quantify information flows between geopolitical risk (GPR) and global financial assets such as equity, bonds, and commodities, with a focus on the Russian-Ukrainian conflict. We combine transfer ...entropy and the I-CEEMDAN framework to measure information flows at multi-term scales. Our empirical results indicate that (i) in the short term, crude oil and Russian equity show opposite responses to GPR; (ii) in the medium and long term, GPR information increases the risk in the financial market; and (iii) the efficiency of the financial asset markets can be confirmed on a long-term scale. These findings have important implications for market participants, such as investors, portfolio managers, and policymakers.
Non-coding RNAs (ncRNAs), such as microRNAs or long ncRNAs, have brought about a new paradigm in the regulation of gene expression. Sequencing technologies have detected transcripts with tremendous ...sensitivity and throughput and revealed that the majority of them lack protein-coding potential. Myriad articles have investigated numerous ncRNAs and many of them claim that ncRNAs play gene-regulatory roles. However, it is questionable whether all these articles draw conclusions through cautious gain- and loss-of function experiments whose design was reasonably based on an ncRNA's correct identity and features. In this review, these issues are discussed with a regulatory ncRNA, nc886, as an example case to represent cautions and guidelines when studying ncRNAs.
This study conducted partial and multiple wavelet coherence analysis to investigate the impact of geopolitical risks(GPR) on the volatility of stock indices in North-East Asian countries, namely ...South Korea, Japan, and China. We employed the GPR and Korea GPR indices to assess these risks. The empirical findings reveal (i) a strong interdependence between the GPR and the volatility of the three stock markets in the short term; (ii) the stock markets of South Korea and Japan have more co-movement with the GPR, rather than the KGPR; and (iii) the GPR index and volatility have a time dependent relationship.
•We investigate the impact of geopolitical risks(GPR) on the volatility of stock indices in North-East Asian countries, namely South Korea, Japan, and China.•We employ the GPR and Korea GPR indices to assess geopolitical risks.•We use partial and multiple wavelet coherence techniques to investigate the relationship of stock markets and GPR.•We find that a strong interdependence between the GPR and the volatility of the three stock markets in the short term.•We further find that the stock markets of South Korea and Japan have more co-movement with the GPR, rather than the Korea GPR.
Commentary to:
Down-regulation of c-FLIP, XIAP and Mcl-1 protein as well as depletion of reduced glutathione contribute to the apoptosis induction of glycyrrhenitic acid derivatives in leukemia cells
...Dandan Song, Yuan Gao, Rui Wang, Dan Liu, Linxiang Zhao and Yongkui Jing
Strigolactones (SLs) are plant hormones that inhibit shoot branching. DWARF14 (D14) inhibits rice tillering and is an SL receptor candidate in the branching inhibition pathway, whereas the close ...homologue DWARF14‐LIKE (D14L) participates in the signaling pathway of karrikins (KARs), which are derived from burnt vegetation as smoke stimulants of seed germination. We provide the first evidence for direct binding of the bioactive SL analogue GR24 to D14. Isothermal titration calorimetry measurements show a D14–GR24 binding affinity in the sub‐micromolar range. Similarly, bioactive KAR1 directly binds D14L in the micromolar range. The crystal structure of rice D14 shows a compact α‐/β‐fold hydrolase domain forming a deep ligand‐binding pocket capable of accommodating GR24. Insertion of four α‐helices between β6 strand and αD helix forms the helical cap of the pocket, although the pocket is open to the solvent. The pocket contains the conserved catalytic triad Ser‐His‐Asp aligned with the oxyanion hole, suggesting hydrolase activity. Although these structural characteristics are conserved in D14L, the D14L pocket is smaller than that of D14. The KAR‐insensitive mutation kai2‐1 is located at the prominent long β6‐αD1 loop, which is characteristic in D14 and D14L, but not in related α‐/β‐fold hydrolases.
Summary
Stem pitting is a common virus‐induced disease phenotype that tremendously impacts growth of perennial woody plants. How stem pitting develops in the infected trees remains unclear.
Here, we ...assessed the development of stem pits upon infection of citrus by Citrus tristeza virus (CTV), which has been regarded as ‘phloem‐limited’. By taking advantage of a highly susceptible virus host – Citrus macrophylla – and a CTV isolate lacking a viral effector – the p33 protein, the development pattern of stem pitting was revealed via time‐course observations and histological analyses.
The stem pits result from the virus‐colonized nonlignified ‘gumming’ malformations which are initiated by virus invasion into multiple spatially separated tissue layers – protophloem, metaphloem, and, unexpectedly, metaxylem. Notably, invasion of CTV into the unspecialized metaxylem cells interrupted the differentiation of the xylem tracheary elements. With the radial spread of CTV into the adjacent cells towards the stem periphery, the clusters of virus‐colonized immature metaxylem cells extended in size, merging, at a certain stage, with virus‐bearing cells in the protophloem and metaphloem layers.
Collectively, our data provide a new insight into the process of the stem pitting development and the role of the xylem tissue in the virus pathogenicity.
Metal-containing Fenton catalysts have been widely investigated. Here, we report for the first time a highly effective stable metal-free Fenton-like catalyst with dual reaction centers consisting of ...4-phenoxyphenol-functionalized reduced graphene oxide nanosheets (POP-rGO NSs) prepared through surface complexation and copolymerization. Experimental and theoretical studies verified that dual reaction centers are formed on the C–O–C bridge of POP-rGO NSs. The electron-rich center around O is responsible for the efficient reduction of H2O2 to •OH, while the electron-poor center around C captures electrons from the adsorbed pollutants and diverts them to the electron-rich area via the C–O–C bridge. By these processes, pollutants are degraded and mineralized quickly in a wide pH range, and a higher H2O2 utilization efficiency is achieved. Our findings address the problems of the classical Fenton reaction and are useful for the development of efficient Fenton-like catalysts using organic polymers for different fields.
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