Categorical Combinatorics for Innocent Strategies

International audienceWe show how to construct the category of games and innocent strategies from a more primitive category of games. On that category we define a comonad and monad with the former distributing over the latter. Innocent strategies are the maps in the induced two-sided Kleisli category. Thus the problematic composition of innocent strategies reflects the use of the distributive law. The composition of simple strategies, and the combinatorics of pointers used to give the comonad and monad are themselves described in categorical terms. The notions of view and of legal play arise naturally in the explanation of the distributivity. The category-theoretic perspective provides a clear discipline for the necessary combinatorics

Sondage national sur la formation à distance et l’apprentissage en ligne

Disponible en anglais dans EDUQ.info sous le titre "Tracking Online and Distance Education in Canadian Universities and Colleges: 2018"Le premier sondage complet sur la formation à distance et l’apprentissage en ligne mené auprès des établissements d’enseignement postsecondaire publics du Canada, dans chaque province et chaque territoire et pour tous les types d’établissements, a été réalisé en 2017. Les résultats avaient montré que l’apprentissage en ligne se portait très bien dans les établissements postsecondaires canadiens, 85 % de l’ensemble des établissements répondants ayant offert en 2016 des cours en ligne crédités, sans compter que des cours en ligne étaient offerts dans presque tous les domaines d’études dans un établissement ou un autre. Les deux tiers des établissements répondants considéraient que l’apprentissage en ligne était très ou extrêmement important pour leur avenir à long terme. L’étude de 2018 s’appuie sur les résultats de l’année dernière, et comprend une liste élargie d’établissements, un questionnaire modifié avec des questions plus détaillées, ainsi que des définitions et des questions plus précises ayant trait aux inscriptions. Les établissements répondants représentent 92 % de la population étudiante postsecondaire du Canada

Long-term photometric behaviour of outbursting AM CVn systems

The AM CVn systems are a class of He-rich, post-period minimum, semidetached, ultracompact binaries. Their long-term light curves have been poorly understood due to the few systems known and the long (hundreds of days) recurrence times between outbursts. We present combined photometric light curves from the Lincoln Near Earth Asteroid Research, Catalina Real-Time Transient Survey, and Palomar Transient Factory synoptic surveys to study the photometric variability of these systems over an almost 10 yr period. These light curves provide a much clearer picture of the outburst phenomena that these systems undergo. We characterize the photometric behaviour of most known outbursting AM CVn systems and establish a relation between their outburst properties and the systems’ orbital periods. We also explore why some systems have only shown a single outburst so far and expand the previously accepted phenomenological states of AM CVn systems. We conclude that the outbursts of these systems show evolution with respect to the orbital period, which can likely be attributed to the decreasing mass transfer rate with increasing period. Finally, we consider the number of AM CVn systems that should be present in modelled synoptic surveys

Technology Learning Curves for Energy Policy Support

The European Commission's Joint Research Centre and the Energy Research Centre of the Netherlands (ECN) organised an expert workshop on 'Learning Curves for Policy Support' in Amsterdam on 8 March 2012. It aimed to assess the challenges in the application of the two-factor learning curve, or alternative solutions in supporting policy decision making in the framework of the European Strategic Energy Technology Plan, and explored options for improvement. The workshop gathered distinguished experts in the field of scientific research on learning curves and policy researchers from the European Commission and ECN to assess the challenges in the application of the two-factor-learning curve, or alternative solutions in supporting policy decision making, and to provide options for improvement. This paper forms the summary of outcomes from the workshop. Due to the very different nature of the One-Factor-Learning concept and the Two-Factor-Learning concept, these are discussed in separate parts. In each of these parts the context and the methodology are introduced, methodological and data challenges are described and the problems associated with the application of the concept in models is discussed.JRC.F.6-Energy systems evaluatio

A transient homotypic interaction model for the influenza A virus NS1 protein effector domain

Influenza A virus NS1 protein is a multifunctional virulence factor consisting of an RNA binding domain (RBD), a short linker, an effector domain (ED), and a C-terminal 'tail'. Although poorly understood, NS1 multimerization may autoregulate its actions. While RBD dimerization seems functionally conserved, two possible apo ED dimers have been proposed (helix-helix and strand-strand). Here, we analyze all available RBD, ED, and full-length NS1 structures, including four novel crystal structures obtained using EDs from divergent human and avian viruses, as well as two forms of a monomeric ED mutant. The data reveal the helix-helix interface as the only strictly conserved ED homodimeric contact. Furthermore, a mutant NS1 unable to form the helix-helix dimer is compromised in its ability to bind dsRNA efficiently, implying that ED multimerization influences RBD activity. Our bioinformatical work also suggests that the helix-helix interface is variable and transient, thereby allowing two ED monomers to twist relative to one another and possibly separate. In this regard, we found a mAb that recognizes NS1 via a residue completely buried within the ED helix-helix interface, and which may help highlight potential different conformational populations of NS1 (putatively termed 'helix-closed' and 'helix-open') in virus-infected cells. 'Helix-closed' conformations appear to enhance dsRNA binding, and 'helix-open' conformations allow otherwise inaccessible interactions with host factors. Our data support a new model of NS1 regulation in which the RBD remains dimeric throughout infection, while the ED switches between several quaternary states in order to expand its functional space. Such a concept may be applicable to other small multifunctional proteins

Direct Anastomosis of the Donor Hepatic Artery to the Supraceliac Aorta without Extension Graft during Adult Liver Transplant in the Era of Extended Criteria Donors: Report of a Case

Arguably, one of the most challenging aspects of liver transplant surgery is the hepatic artery reconstruction. When the donor and recipient arteries are normal, this anastomosis can still be difficult. However, when the recipient artery has been dissected or is small other alternative reconstructions must be considered. Routinely, the donor surgery includes removing the iliac artery and vein specifically to aid in alternative reconstruction techniques. With the increase use of extended criteria donors (i.e., specifically age >55) the iliac vessel may be unusable because of atherosclerotic disease. This paper describes revisiting an alternative technique for hepatic artery reconstruction during cadaveric liver transplant when the recipient artery has been dissected and the iliac vessels were unusable secondary to arterial plaque from a 75 yo donor. Herein, we describe the successful anastomosis of the celiac artery with aortic patch from the donor directly to the supraceliac aorta of the adult recipient

Probing ISM Structure in Trumpler 14 & Carina I Using The Stratospheric Terahertz Observatory 2

We present observations of the Trumpler 14/Carina I region carried out using the Stratospheric Terahertz Observatory 2 (STO2). The Trumpler 14/Carina I region is in the west part of the Carina Nebula Complex, which is one of the most extreme star-forming regions in the Milky Way. We observed Trumpler 14/Carina I in the 158 $\mu$m transition of [C\,{\sc ii}] with a spatial resolution of 48$''$ and a velocity resolution of 0.17 km s$^{-1}$. The observations cover a 0.25$^\circ$ by 0.28$^\circ$ area with central position {\it l} = 297.34$^\circ$, {\it b} = -0.60$^\circ$. The kinematics show that bright [C\,{\sc ii}] structures are spatially and spectrally correlated with the surfaces of CO clouds, tracing the photodissociation region and ionization front of each molecular cloud. Along 7 lines of sight that traverse Tr 14 into the dark ridge to the southwest, we find that the [C\,{\sc ii}] luminosity from the HII region is 3.7 times that from the PDR. In same los we find in the PDRs an average ratio of 1:4.1:5.6 for the mass in atomic gas:dark-CO gas: molecular gas traced by CO. Comparing multiple gas tracers including HI 21cm, [C\,{\sc ii}], CO, and radio recombination lines, we find that the HII regions of the Carina Nebula Complex are well-described as HII regions with one-side freely expanding towards us, consistent with the champagne model of ionized gas evolution. The dispersal of the GMC in this region is dominated by EUV photoevaporation; the dispersal timescale is 20-30 Myr.Comment: ApJ accepte

Genome Sequencing and Pan-Genome Analysis of 23 Corallococcus spp. Strains Reveal Unexpected Diversity, With Particular Plasticity of Predatory Gene Sets

Corallococcus is an abundant genus of predatory soil myxobacteria, containing two species, C. coralloides (for which a genome sequence is available) and C. exiguus. To investigate the genomic basis of predation, we genome-sequenced 23 Corallococcus strains. Genomic similarity metrics grouped the sequenced strains into at least nine distinct genomospecies, divided between two major sub-divisions of the genus, encompassing previously described diversity. The Corallococcus pan-genome was found to be open, with strains exhibiting highly individual gene sets. On average, only 30.5% of each strain’s gene set belonged to the core pan-genome, while more than 75% of the accessory pan-genome genes were present in less than four of the 24 genomes. The Corallococcus accessory pan-proteome was enriched for the COG functional category “Secondary metabolism,” with each genome containing on average 55 biosynthetic gene clusters (BGCs), of which only 20 belonged to the core pan-genome. Predatory activity was assayed against ten prey microbes and found to be mostly incongruent with phylogeny or BGC complement. Thus, predation seems multifactorial, depending partially on BGC complement, but also on the accessory pan-genome – genes most likely acquired horizontally. These observations encourage further exploration of Corallococcus as a source for novel bioactive secondary metabolites and predatory proteins.</p