Asynchronous Proactive RSA

Nowadays, to model practical systems better, such as the Internet network and ad hoc networks, researchers usually regard these systems as asynchronous networks. Meanwhile, proactive secret sharing schemes are often employed to tolerate a mobile adversary. Considering both aspects, an asynchronous proactive threshold signature scheme is needed to keep computer systems secure. So far, two asynchronous proactive secret sharing schemes have been proposed. One is proposed by Zhou in 2001, which is for RSA schemes. The other scheme is proposed by Cachin in 2002, which is a proactive secret sharing scheme for discrete-log schemes. There exist several drawbacks in both schemes. In Zhou¡¯s scheme, the formal security proof of this scheme is missing. Furthermore, Zhou¡¯s scheme needs to resort to the system administrator as the trusted third party for further run when some Byzantine errors occur. In Cachin¡¯s scheme, the building block is based on the threshold RSA scheme proposed by Shoup. However, how to proactivize Shoup¡¯s scheme is omitted in Cachin¡¯s scheme, so this scheme is incomplete. In this paper, we present a complete provably secure asynchronous proactive RSA scheme (APRS). Our paper has four contributions. Firstly, we present a provably secure asynchronous verifiable secret sharing for RSA schemes (asynchronous verifiable additive secret sharing, AVASS), which is based on a verifiable additive secret sharing over integers. Secondly, we propose an asynchronous threshold RSA signature scheme that is based on the AVASS scheme and the random oracle model, and is capable of being proactivized. Thirdly, we present a provably secure threshold coin-tossing scheme on the basis of the above threshold RSA scheme. Fourthly, we propose an asynchronous proactive secret sharing based on the threshold RSA scheme and the coin-tossing scheme. Finally, combining the proactive secret sharing scheme and the threshold RSA scheme, we achieve a complete provably secure asynchronous proactive RSA scheme

Earnings Surprises, Investor Sentiments and Contrarian Strategies

This study documents that contrarian investment strategies offer superior returns because these strategies exploit investors' expectation errors. There are two sources of expectation errors, naïve extrapolation of past performance and biased analysts' earnings forecasts. Our results suggest that investors naively extrapolate past performance and overestimate the future growth rates of glamour stocks relative to value stocks. In addition, analysts tend to be excessively pessimistic about value stocks and over optimistic about glamour stocks. We find that both positive earnings surprises and negative earnings surprises significantly affect subsequent returns. However, negative earnings surprises have less impact on value stocks relative to glamour stocks. We also find new evidence that investor sentiments could be an alternative source of superior performances from value stocks. Our results indicate that when the investor sentiment is higher, value stocks earn significant higher returns than glamour stocks.  Keywords: contrarian strategy, value and glamour stocks, earnings surprise, investor sentiments JEL Classifications: G02, G11, G14

Support for wildlife consumption bans and policies in China post-Covid-19

The Covid-19 pandemic, which probably arose from zoonotic sources, has provoked wide-ranging discussion on which wildlife policies can best prevent future pandemics. More work needs to be done to investigate support for regulatory frameworks in China post-Covid-19 and specifically to model how perceptions of the relationship between wildlife consumption and risk of zoonotic diseases combine with other variables to influence support for wildlife policies. We report on a 2021 quantitative survey conducted in China. The objectives were to measure attitudes towards the current wildlife consumption ban and wildlife regulations in China and to model which variables correlate with support for bans on wild-caught and farmed wildlife. The sample was almost evenly split between considering the ban on wild animal consumption in China to be adequate (45%) or not strict enough (42%). Protection against future pandemics and protection of the environment were motivators for supporting the ban for c. 80% of respondents. The results also indicated strong support for wildlife bans. A majority of respondents supported bans of both wild-caught and farmed wildlife, although support for bans of wild-caught animals was greater for most taxa. Furthermore, the perceived zoonotic risk of a taxon was a more prevalent correlate of support for a ban for wild-caught wildlife than for farmed wildlife. Our results indicate substantial support for the current wildlife consumption ban in China, and opportunities to further mitigate the environmental and zoonotic risks of wildlife consumption

Achieving Win–Win Solutions in Telecoupled Human–Land Systems

Telecoupling refers to socioeconomic and environmental interactions between distant places. Telecoupling is becoming even more significant in the increasingly globalized world and it plays a key role in the emergence of major global environmental problems. In particular, it contributes to land degradation and the achievement of the United Nations’ Sustainable Development Goals (SDGs). However, there is a lack of systematic examination of the impacts of telecoupling on land system change, and how to respond to the undesirable impacts. Based on CiteSpace Software, here we analyze the current research status of telecoupled human–land systems, including publications, major scientific research institutions, and research processes. We explore the impacts of telecoupling on land and how to respond to these impacts. Finally, we propose a framework that is composed of impact identification, system integration, and responses to achieve a win-win situation in telecoupled human–land systems. The framework can help to create a sustainable future for telecoupled human–land systems

A framework to evaluate land degradation and restoration responses for improved planning and decision-making

Avoiding, reducing or reversing land degradation will require increased restoration investments, carefully targeted and implemented to maximize environmental, economic and social benefits. Our objective was to develop a multi-criteria framework to assess effectiveness of land degradation responses for enhanced land use planning and restoration by evaluating both direct biophysical and socio-economic responses and indirect effects of various restoration strategies. The effectiveness of restoration responses is demonstrated for degraded forestland using a comprehensive literature review and case study in Nepal. The results show that most forestland restoration responses have an ecological focus with tree planting being the dominant direct response and economic and financial instruments the indirect responses. The results confirmed that environmental desirability was the dominant factor and economic feasibility was secondary for assessing restoration responses. Cultural acceptability was given the least consideration. Among sub-criteria, improved vegetative structure was the dominant restoration response. This study, originating from the Land Degradation and Restoration Assessment of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services, supports the view that the scientific community and decision-makers must give greater attention to cultural, social, technical, and political dimensions that influence the outcomes of restoration responses to solve the pervasive problem of land degradation

Catalytic promiscuity of O-methyltransferases from Corydalis yanhusuo leading to the structural diversity of benzylisoquinoline alkaloids

O-methyltransferases play essential roles in producing structural diversity and improving the biological properties of benzylisoquinoline alkaloids (BIAs) in plants. In this study, Corydalis yanhusuo, a plant used in traditional Chinese medicine due to the analgesic effects of its BIA-active compounds, was employed to analyze the catalytic characteristics of O-methyltransferases in the formation of BIA diversity. Seven genes encoding O-methyltransferases were cloned, and functionally characterized using seven potential BIA substrates. Specifically, an O-methyltransferase (CyOMT2) with highly efficient catalytic activity of both 4′- and 6-O-methylations of 1-BIAs was found. CyOMT6 was found to perform two sequential methylations at both 9- and 2-positions of the essential intermediate of tetrahydroprotoberberines, (S)-scoulerine. Two O-methyltransferases (CyOMT5 and CyOMT7) with wide substrate promiscuity were found, with the 2-position of tetrahydroprotoberberines as the preferential catalytic site for CyOMT5 (named scoulerine 2-O-methyltransferase) and the 6-position of 1-BIAs as the preferential site for CyOMT7. In addition, results of integrated phylogenetic molecular docking analysis and site-directed mutation suggested that residues at sites 172, 306, 313, and 314 in CyOMT5 are important for enzyme promiscuity related to O-methylations at the 6- and 7-positions of isoquinoline. Cys at site 253 in CyOMT2 was proved to promote the methylation activity of the 6-position and to expand substrate scopes. This work provides insight into O-methyltransferases in producing BIA diversity in C. yanhusuo and genetic elements for producing BIAs by metabolic engineering and synthetic biology

Genetic characterization and virulence determinants of multidrug-resistant NDM-1-producing Aeromonas caviae

The emergence of carbapenemase significantly threatens public health. It is prevalent worldwide but rare in Aeromonas caviae. Unlike most bacterial species, A. caviae has two distinct flagella systems, which are closely related to biofilm formation. The ability to form biofilms on host tissues or inert surfaces constitutes an important cause of many persistent infections, which causes difficulties in clinical treatment. Here, we report on a multidrug-resistant (MDR) A. caviae carrying blaNDM–1 with a novel sequence type 1,416. The strong ability of biofilm formation of FAHZZU2447 was verified by a crystal violet assay. The resistome profile and location of the blaNDM–1 gene were determined by antimicrobial susceptibility testing, S1 nuclease pulsed-field gel electrophoresis (S1-PFGE), and Southern blot analysis. Moreover, the strain underwent whole-genome sequencing to identify its genomic characteristics. In addition, the blaNDM–1 gene was located on a ∼243 kb plasmid with genetic context IS1R-blaNDM–1-ble-trpF-dsbD-hp-sul1-qacE. Phylogenetic analysis indicated the transmission of A. caviae in China, Japan, and Thailand. Our study aimed to elucidate the genomic features of blaNDM–1-producing A. caviae, thereby clarifying the distribution of A. caviae worldwide and emphasizing the harmfulness of biofilm formation to the clinic. Further comprehensive surveillance of this species is needed to control further dissemination

Expansion within the CYP71D subfamily drives the heterocyclization of tanshinones synthesis in Salvia miltiorrhiza

Tanshinones are the bioactive nor-diterpenoid constituents of the Chinese medicinal herb Danshen (Salvia miltiorrhiza). These groups of chemicals have the characteristic furan D-ring, which differentiates them from the phenolic abietane-type diterpenoids frequently found in the Lamiaceae family. However, how the 14,16-epoxy is formed has not been elucidated. Here, we report an improved genome assembly of Danshen using a highly homozygous genotype. We identify a cytochrome P450 (CYP71D) tandem gene array through gene expansion analysis. We show that CYP71D373 and CYP71D375 catalyze hydroxylation at carbon-16 (C16) and 14,16-ether (hetero)cyclization to form the D-ring, whereas CYP71D411 catalyzes upstream hydroxylation at C20. In addition, we discover a large biosynthetic gene cluster associated with tanshinone production. Collinearity analysis indicates a more specific origin of tanshinones in Salvia genus. It illustrates the evolutionary origin of abietane-type diterpenoids and those with a furan D-ring in Lamiaceae