On differences between fractional and integer order differential equations for dynamical games

We argue that fractional order (FO) differential equations are more suitable to model complex adaptive systems (CAS). Hence they are applied in replicator equations for non-cooperative game. Rock-Scissors-Paper game is discussed. It is known that its integer order model does not have a stable equilibrium. Its fractional order model is shown to have a locally asymptotically stable internal solution. A FO asymmetric game is shown to have a locally asymptotically stable internal solution. This is not the case for its integer order counterpart.Comment: 4 page

Scalable Decentralized Cooperative Platoon using Multi-Agent Deep Reinforcement Learning

Cooperative autonomous driving plays a pivotal role in improving road capacity and safety within intelligent transportation systems, particularly through the deployment of autonomous vehicles on urban streets. By enabling vehicle-to-vehicle communication, these systems expand the vehicles environmental awareness, allowing them to detect hidden obstacles and thereby enhancing safety and reducing crash rates compared to human drivers who rely solely on visual perception. A key application of this technology is vehicle platooning, where connected vehicles drive in a coordinated formation. This paper introduces a vehicle platooning approach designed to enhance traffic flow and safety. Developed using deep reinforcement learning in the Unity 3D game engine, known for its advanced physics, this approach aims for a high-fidelity physical simulation that closely mirrors real-world conditions. The proposed platooning model focuses on scalability, decentralization, and fostering positive cooperation through the introduced predecessor-follower "sharing and caring" communication framework. The study demonstrates how these elements collectively enhance autonomous driving performance and robustness, both for individual vehicles and for the platoon as a whole, in an urban setting. This results in improved road safety and reduced traffic congestion

An extremely low-noise heralded single-photon source: a breakthrough for quantum technologies

Low noise single-photon sources are a critical element for quantum technologies. We present a heralded single-photon source with an extremely low level of residual background photons, by implementing low-jitter detectors and electronics and a fast custom-made pulse generator controlling an optical shutter (a LiNbO3 waveguide optical switch) on the output of the source. This source has a second-order autocorrelation g^{(2)}(0)=0.005(7), and an "Output Noise Factor" (defined as the ratio of the number of noise photons to total photons at the source output channel) of 0.25(1)%. These are the best performance characteristics reported to date

Crystal Structure of Cas9 in Complex with Guide RNA and Target DNA

The CRISPR-associated endonuclease Cas9 can be targeted to specific genomic loci by single guide RNAs (sgRNAs). Here, we report the crystal structure of Streptococcus pyogenes Cas9 in complex with sgRNA and its target DNA at 2.5 Å resolution. The structure revealed a bilobed architecture composed of target recognition and nuclease lobes, accommodating the sgRNA:DNA heteroduplex in a positively charged groove at their interface. Whereas the recognition lobe is essential for binding sgRNA and DNA, the nuclease lobe contains the HNH and RuvC nuclease domains, which are properly positioned for cleavage of the complementary and noncomplementary strands of the target DNA, respectively. The nuclease lobe also contains a carboxyl-terminal domain responsible for the interaction with the protospacer adjacent motif (PAM). This high-resolution structure and accompanying functional analyses have revealed the molecular mechanism of RNA-guided DNA targeting by Cas9, thus paving the way for the rational design of new, versatile genome-editing technologies.National Institutes of Health (U.S.) (Grant 5DP1-MH100706

Outbreaks of myxomatosis in Egyptian domestic rabbit farms

[EN] Myxomatosis is an endemic infectious, severe and often fatal disease of rabbit caused by myxoma virus. In the present study, myxomatosis outbreaks were reported in 7 domestic rabbit farms in Egypt. Rabbits showed oedema of the eyelids, facial oedema and blepharoconjunctivitis. The morbidity and lethality rates were 18-100% and 20-80%, respectively. The myxomatosis diagnosis was based on histopathology, virus isolation on rabbit kidney cell line (RK-13), polymerase chain reaction (PCR) and sequence analysis. Histopathological examination revealed the presence of epidermal hyperplasia, dermal necrosis and intracytoplasmic eosinophilic inclusion bodies. The virus was isolated on RK-13 cells and induced cytopathic effect. Using PCR, a band of 471 base pair corresponding to the M071L gene was amplified from extracted DNA. Sequence alignment of four out of the 7 isolates revealed that these isolates were 98-99% identical to European and Australian rabbit myxoma reference viruses. In conclusion, rabbit myxomatosis outbreaks and virus isolation procedures are reported herein for the first time in Egypt. Preventive policies against disease circulation should be adopted by the national authorities.Salem, HM.; Morsy, EA.; Hassanen, EI.; Shehata, AA. (2019). Outbreaks of myxomatosis in Egyptian domestic rabbit farms. World Rabbit Science. 27(2):85-91. https://doi.org/10.4995/wrs.2019.10585SWORD8591272Bertagnoli S., Marchandeau S. 2015. Myxomatosis. Rev. Sci. Tech., 34:549-556. https://doi.org/10.20506/rst.34.2.2378Best S.M., Collins S.V., Kerr P.J. 2000. Coevolution of host and virus: cellular localization of virus in myxoma virus infection of resistant and susceptible European rabbits. Virology, 277: 76-91. https://doi.org/10.1006/viro.2000.0505Brugman V.A., Hernández-Triana L.M., Prosser S.W., Weland.C., Westcott D.G., Fooks A.R., Johnson N. 2015. Molecular species identification, host preference and detection of myxoma virus in the Anopheles maculipennis complex (Diptera: Culicidae ) in southern England, UK. Parasit Vectors., 8: 421. https://doi.org/10.1186/s13071-015-1034-8Calvete C., Estrada R., Lucientes J., Osacar J., Villafuerte R. 2004. Effects of vaccination against viral haemorrhagic disease (VHD) and myxomatosis on long-term mortality rates of European wild rabbits. Vet. Rec., 155: 388-392. https://doi.org/10.1136/vr.155.13.388Cameron C., Hota-Mitchell S., Chen L., Barrett J., Cao J.X., Macaulay C., Willer D., Evans D., McFadden G. 1999. The complete DNA sequence of myxoma virus. Virology, 264: 298-318. https://doi.org/10.1006/viro.1999.0001Dalton K.P., Nicieza I., de Llano D., Gullón J., Inza M., Petralanda M., Arroita Z., Parra F. 2015. Vaccine breaks: Outbreaks of myxomatosis on Spanish commercial rabbit farms. Vet. Microbiol. 178: 208-216. https://doi.org/10.1016/j.vetmic.2015.05.008Fenner F. 2000. Adventures with poxviruses of vertebrates. FEMS Microbiol. Rev., 24:123-133.https://doi.org/10.1111/j.1574-6976.2000.tb00536.xFerreira, C., Ramírez, E., Castro, F., Ferreras, P., Alves, P.C., Redpath, S., Villafuerte, R. 2009. Field experimental vaccination campaigns against myxomatosis and their effectiveness in the wild. Vaccine, 27: 6998-7002.https://doi.org/10.1016/j.vaccine.2009.09.075Grodhaus G., Regnery D.C., Marshall I.D. 1963. Studies in the epidemiology of myxomatosis in California. II. The experimental transmission of myxomatosis between brush rabbits (Sylvilagus bachmani ) by several species of mosquitoes. Am. J. Hyg., 77: 205-212. https://doi.org/10.1093/oxfordjournals.aje.a120311Kerr P., McFadden G. 2002. Immune responses to myxoma virus. Viral Immunol., 15: 229-246. https://doi.org/10.1089/08828240260066198Kerr P.J. 2012. Myxomatosis in Australia and Europe: a model for emerging infectious diseases. Antiviral Res., 93: 387-415. https://doi.org/10.1016/j.antiviral.2012.01.009Moss B. 2001. Poxviridae: The viruses and their replication. In: Fields B.N., Howley M.D., Griffin Ph.D., Lamb Ph.D., Martin M.D., Roizman B., Strauss M.D., Knipe Ph. D. (Eds.), Fields' virology, 4th ed., Lippincott Williams & Wilkins, Philadelphia. PA, USA. pp. 2849-2883.OIE. 2107. Manual of Diagnostic tests and vaccines for terrestrial animals. Chapter 2.6.1. Myxomatosis(NB: Version adopted in May 2014).Silvers L., Inglis B., Labudovic A., Janssens P.A., van Leeuwen B.H., Kerr P.J. 2006. Virulence and pathogenesis of the MSW and MSD strains of Californian myxoma virus in European rabbits with genetic resistance to myxomatosis compared to rabbits with no genetic resistance. Virology, 348: 72-83. https://doi.org/10.1016/j.virol.2005.12.007Willer D.O., McFadden G., Evans D.H. 1999. The complete genome sequence of Shope (rabbit) fibroma virus. Virology, 264: 319-343. https://doi.org/10.1006/viro.1999.000

Diversity of Coronaviruses with Particular Attention to the Interspecies Transmission of SARS-CoV-2

In December 2019, the outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was reported in China with serious impacts on global health and economy that is still ongoing. Although interspecies transmission of coronaviruses is common and well documented, each coronavirus has a narrowly restricted host range. Coronaviruses utilize different receptors to mediate membrane fusion and replication in the cell cytoplasm. The interplay between the receptor-binding domain (RBD) of coronaviruses and their coevolution are determinants for host susceptibility. The recently emerged SARS-CoV-2 caused the coronavirus disease 2019 (COVID-19) pandemic and has also been reported in domestic and wild animals, raising the question about the responsibility of animals in virus evolution. Additionally, the COVID-19 pandemic might also substantially have an impact on animal production for a long time. In the present review, we discussed the diversity of coronaviruses in animals and thus the diversity of their receptors. Moreover, the determinants of the susceptibility of SARS-CoV-2 in several animals, with special reference to the current evidence of SARS-CoV-2 in animals, were highlighted. Finally, we shed light on the urgent demand for the implementation of the One Health concept as a collaborative global approach to mitigate the threat for both humans and animals