Artificial intelligence in space

In the next coming years, space activities are expected to undergo a radical transformation with the emergence of new satellite systems or new services which will incorporate the contributions of artificial intelligence and machine learning defined as covering a wide range of innovations from autonomous objects with their own decision-making power to increasingly sophisticated services exploiting very large volumes of information from space. This chapter identifies some of the legal and ethical challenges linked to its use. These legal and ethical challenges call for solutions which the international treaties in force are not sufficient to determine and implement. For this reason, a legal methodology must be developed that makes it possible to link intelligent systems and services to a system of rules applicable thereto. It discusses existing legal AI-based tools amenable for making space law actionable, interoperable and machine readable for future compliance tools.Comment: 32 page

Sur les écoulements de disque tournant

Les écoulements de disque(s) tournant(s) trouvent des applications dans des domaines très variés comme l'astrophysique, la géophysique et surtout les turbomachines. Une majeure partie de cette étude concerne d'ailleurs les écoulements turbulents de type rotor-stator soumis à un flux axial, écoulements que l'on retrouve dans la turbopompe à hydrogène liquide du moteur Vulcain d'Ariane V. D'un point de vue fondamental, ils offrent une géométrie simple ou la rotation influence la structure de la turbulence. Cet article présente une revue sur les écoulements confinés entre un disque tournant et un disque fixe avec ou sans flux imposé pour une gamme de rapport d'aspect couvrant les écoulements de type Batchelor à couches limites séparées et les écoulements de type Couette de torsion à couches limites jointes. Ces écoulements ont été abordés sous différents aspects: stabilité, transition vers la turbulence et écoulements pleinement turbulents, que ce soit expérimentalement ou par simulation numérique. Des résultats concernant des écoulements turbulents avec transferts de chaleur, plus proches des écoulements industriels, sont également présentés

Twist: A Regulator of Epithelial-Mesenchymal Transition in Lung Fibrosis

BACKGROUND: Several studies have implicated viral infection as an important factor in the pathogenesis of IPF and related fibrotic lung disorders. Viruses are thought to cause epithelial cell injury and promote epithelial-mesenchymal transition (EMT), a process whereby differentiated epithelial cells undergo transition to a mesenchymal phenotype, and considered a source of fibroblasts in the setting of lung injury. We have demonstrated an association between the epithelial injury caused by chronic herpes virus infection with the murine gamma-herpes virus, MHV68, and lung fibrosis. We hypothesize that EMT in this model of virus-induced pulmonary fibrosis is driven by the expression of the transcription factor Twist. METHODS/FINDINGS: In vitro MHV68 infection of murine lung epithelial cells induced expression of Twist, and mesenchymal markers. Stable overexpression of Twist promoted EMT in MLE15 lung epithelial cells. Transient knockdown expression of Twist resulted in preservation of epithelial phenotype after in vitro MHV68 infection. In concordance, high expression of Twist was found in lung epithelial cells of MHV68 infected mice, but not in mock infected mice. Alveolar epithelial cells from lung tissue of idiopathic pulmonary fibrosis (IPF) patients were strongly positive for Twist. These cells demonstrated features of EMT with low expression of E-cadherin and upregulation of the mesenchymal marker N-cadherin. Finally, IPF tissue with high Twist protein levels was also positive for the herpesvirus, EBV. CONCLUSIONS/SIGNIFICANCE: We conclude that Twist contributes to EMT in the model of virus-induced pulmonary fibrosis. We speculate that in some IPF cases, gamma-herpes virus infection with EBV might be a source of injury precipitating EMT through the expression of Twist

Slow-Speed Supernovae from the Palomar Transient Factory: Two Channels

Since the discovery of the unusual prototype SN 2002cx, the eponymous class of low-velocity, hydrogen-poor supernovae has grown to include at most another two dozen members identified from several heterogeneous surveys, in some cases ambiguously. Here we present the results of a systematic study of 1077 hydrogen-poor supernovae discovered by the Palomar Transient Factory, leading to nine new members of this peculiar class. Moreover we find there are two distinct subclasses based on their spectroscopic, photometric, and host galaxy properties: The "SN 2002cx-like" supernovae tend to be in later-type or more irregular hosts, have more varied and generally dimmer luminosities, have longer rise times, and lack a Ti II trough when compared to the "SN 2002es-like" supernovae. None of our objects show helium, and we counter a previous claim of two such events. We also find that these transients comprise 5.6+17-3.7% (90% confidence) of all SNe Ia, lower compared to earlier estimates. Combining our objects with the literature sample, we propose that these subclasses have two distinct physical origins.Comment: 49 pages, 36 figures, submitted to Ap

Norspermidine is not a self-produced trigger for biofilm disassembly

SummaryFormation of Bacillus subtilis biofilms, consisting of cells encapsulated within an extracellular matrix of exopolysaccharide and protein, requires the polyamine spermidine. A recent study reported that (1) related polyamine norspermidine is synthesized by B. subtilis using the equivalent of the Vibrio cholerae biosynthetic pathway, (2) exogenous norspermidine at 25 μM prevents B. subtilis biofilm formation, (3) endogenous norspermidine is present in biofilms at 50–80 μM, and (4) norspermidine prevents biofilm formation by condensing biofilm exopolysaccharide. In contrast, we find that, at concentrations up to 200 μM, exogenous norspermidine promotes biofilm formation. We find that norspermidine is absent in wild-type B. subtilis biofilms at all stages, and higher concentrations of exogenous norspermidine eventually inhibit planktonic growth and biofilm formation in an exopolysaccharide-independent manner. Moreover, orthologs of the V. cholerae norspermidine biosynthetic pathway are absent from B. subtilis, confirming that norspermidine is not physiologically relevant to biofilm function in this species

Plasma Cell Granuloma Associated with Pulmonary Actinomycosis: A Case Report

Plasma cell granuloma (PCG) of the lung is a rare disease that usually presents as a pulmonary nodule or mass on incidental radiographic examination without symptoms. Although the etiology of PCG is still controversial, many findings have lent support to the lesion being a reactive inflammatory process rather than a neoplastic one. We describe a 53-yr-old male who presented with a hemoptysis and have a lung mass at the left upper lobe on chest radiograph. The lung mass was primarily diagnosed as PCG by percutaneous needle aspiration and biopsy, and the patient was treated with oral steroid because he and relatives refused the operation. However, the size of the lung mass did not change and open thoracotomy and lobectomy were done therefore. He was confirmed as having pulmonary actinomycosis with PCG after surgery. To our knowledge, this is the first report of PCG associated with actinomycosis in Korea

Political masculinities, crisis tendencies, and social transition: Toward an understanding of change

This introduction to the special issue on “Political Masculinities and Social Transition” rethinks the notion of “crisis in masculinity” and points to its weaknesses, such as cyclical patterns and chronicity. Rather than viewing key moments in history as points of rupture, we understand social change as encompassing ongoing transitions marked by a “fluid nature” (Montecinos 2017, 2). In line with this, the contributions examine how political masculinities are implicated within a wide range of social transitions, such as nation building after war, the founding of a new political party in response to an economic crisis, an “authoritarian relapse” of a democracy, attempts at changing society through terrorism, rapid industrialization as well as peace building in conflict areas. Building on Starck and Sauer’s definition of “political masculinities” we suggest applying the concept to instances in which power is explicitly either being (re)produced or challenged. We distinguish between political masculinities that are more readily identified as such (e.g., professional politicians) and less readily identified political masculinities (e.g., citizens), emphasizing how these interact with each other. We ask whether there is a discernible trajectory in the characteristics of political masculinities brought about by social transition that can be confirmed across cultures. The contributors’ findings indicate that these political masculinities can contribute to different kinds of change that either maintain the status quo, are progressive, retrogressive, or a mixture of these. Revolutionary transitions, it seems, often promote the adherence to traditional forms of political masculinity, whereas more reformatory transition leaves discursive spaces for argument