Dynamical systems theory for music dynamics

We show that, when music pieces are cast in the form of time series of pitch variations, the concepts and tools of dynamical systems theory can be applied to the analysis of {\it temporal dynamics} in music. (i) Phase space portraits are constructed from the time series wherefrom the dimensionality is evaluated as a measure of the {\pit global} dynamics of each piece. (ii) Spectral analysis of the time series yields power spectra ($\sim f^{-\nu}$) close to {\pit red noise} ($\nu \sim 2$) in the low frequency range. (iii) We define an information entropy which provides a measure of the {\pit local} dynamics in the musical piece; the entropy can be interpreted as an evaluation of the degree of {\it complexity} in the music, but there is no evidence of an analytical relation between local and global dynamics. These findings are based on computations performed on eighty sequences sampled in the music literature from the 18th to the 20th century.Comment: To appear in CHAOS. Figures and Tables (not included) can be obtained from [email protected]

Territorializing International Travel Emissions: Geography and Magnitude of the Hidden Climate Footprint of Brussels

In the present article we investigate the geography and magnitude of the climate footprint of long-distance travel with Brussels, Belgium, as a destination. The internationally networked position of this city goes hand in hand with a strong dependence on international mobility, which largely materializes in impressive volumes of long-distance travel and associated consumption of important amounts of fossil fuel. Despite a surge in concerns about global warming, the climate footprint of most international travel, notably air travel, is not included in the official national and regional climate inventories, or in other words, it is not territorialized. The official climate footprint of the Brussels-Capital Region attained 3.7 Mton CO2eq per year (in 2017). Based on our exploratory calculations, however, the total estimated climate footprint of all Brussels-bound international travel equalled an additional 2.7 Mton CO2eq. In terms of geographical distribution, over 70% of international travellers to Brussels come from Europe, while these represent only 15% of the climate footprint of all international travel to Brussels. We conclude that the practice of not allocating emissions caused by international travel to territorial units has kept the magnitude and complexity of this problem largely under the radar and contributes to the lack of societal support for curbing growth of international aviation

Scaling properties of work fluctuations after quenches at quantum transitions

We study the scaling properties of the statistics of the work done on a generic many-body system at a quantum phase transition of any order and type, arising from quenches of a driving control parameter. For this purpose we exploit a dynamic finite-size scaling framework. Namely, we put forward the existence of a nontrivial finite-size scaling limit for the work distribution, defined as the large-size limit when appropriate scaling variables are kept fixed. The corresponding scaling behaviors are thoroughly verified by means of analytical and numerical calculations in two paradigmatic many-body systems as the quantum Ising model and the Bose-Hubbard model.Comment: 30 pages, 6 figures. Revised versio

Les tribulations d’une casserole chinoise au Niger

Les tribulations d’une casserole chinoise au Niger. Partant d’une poterie atypique, exhibée lors d’une enquête dans le Sud-Est du Niger, les auteurs tentent de reconstituer le processus qui a vu des récipients émaillés, fabriqués en Afrique de l’Ouest et en Asie, se substi-tuer progressivement à d’autres produits dans les trousseaux de mariage, pour en venir à incarner la richesse des femmes, leur urbanité et leurs compétences esthétiques. Ce travail vise à collecter des matériaux qui seront discutés et mis en perspective dans l’article suivant (Zeebroek et al, ce volume), lorsqu’il s’agira d’élaborer une grille d’analyse multiscalaire des dynamiques culturelles. Dans la première partie de l’article, la trajectoire des produits émaillés est retracée depuis leur exposition chez les parents de la mariée jusqu’à leur mise en place et leur exhibition dans la chambre de la nouvelle épouse, au domicile du mari. Cette trajectoire permet de saisir les enjeux économiques et sociaux sur lesquels se fondent l’accumulation et l’exposition de tels produits. Les auteurs explorent alors les critères qui sous-tendent la valeur des assemblages matrimoniaux. Celle-ci relève d’abord du nombre et de l’homogénéité des pièces, mais également de leur origine – réelle ou supposée – ce qui entraîne une analyse des circuits d’approvisionnement, partiellement liés aux migrations circulaires et au pèlerinage à LaMecque. La seconde partie de l’article aborde les assemblages matrimoniaux dans une perspective historique. On voit comment les récipients émaillés se sont progressivement substitués aux calebasses dans la plupart des populations du Niger et comment cette substitution a accompagné et engendré d’importantes transformations dans l’économie matrimoniale, le rôle des femmes, la mobilité sociale et les goûts esthétiques. Les auteurs replacent enfin le phénomène dans une perspective géographique plus large, qui permet de comprendre pourquoi les assemblages matrimoniaux comportent des récipients émaillés dans une zone étendue d’Afrique de l’Ouest, mais également pourquoi ces produits ne se sont pas substitués aux calebasses ou à d’autres catégories de biens matrimoniaux dans certaines populations.Tribulations of a Chinese Saucepan in Niger.Starting from a peculiar pottery vessel displayed during an ethnographic fieldwork in South-Eastern Niger, the authors seek to reconstruct the process through which enamelware manufactured in West Africa and Asia have gradually replaced other items in marriage trousseaux and become the main expression of women’s wealth, urbanity, and aesthetic skills. Data hereby gathered are then discussed and analyzed in the next paper (Zeebroek et al., this volume), with a view to develop a multiscalar analytical framework for exploring cultural dynamics. The first part of the paper describes the trajectory of enamelware; from the moment they are displayed in the bride’s home, up to when they are put into place and exhibited in the room the bride will occupy within her husband’s home. This allows for the identification of the social and economical elements at stake in the accumulation and display of such products. Next, the authors explore the criteria underlying the value of marriage trousseaux. These pertain to the number and typological homogeneity of items, but also their origin (real or putative), which requires that supply networks be also taken into consideration, and notably those in connection with circular migrations or the Mecca pilgrimage. In the second part of the paper, marriage trousseaux are put into historical perspective. One sees how enamelware have gradually replaced calabashes in most populations of Southern Niger, and how this replacement has both followed and generated major changes in marital economy, the role of women, and aesthetic tastes. Authors then consider the phenomenon from a wider geographical perspective, which helps to understand why marriage trousseaux incorporate enamelware in a large part of West Africa, but also why such products have not replaced calabashes or other kinds of matrimonial goods in several populations

Nanostructured TiO2 Layers for Photovoltaic and Gas Sensing Applications

Titanium dioxide (TiO2) has been an important material for decades, combining numerous attractive properties in terms of economy (low price, large availability) or ecology (non-toxic), as well as broad physical and chemical possibilities. In the last few years, the development of nanotechnologies offered new opportunities, not only in an academic perspective but also with a view to many applications with particular reference to the environment. This chapter focuses on the many ways that allow to tailor and organize TiO2 crystallites at the nanometre scale to make the most of this amazing material in the field of photovoltaics and gas sensing

Brussels as an international city

Observations The five characteristics discussed below illustrate the importance of internationalisation in Brussels. International connectivity Brussels is a highly connected city, located at the heart of Europe (note that 19% of the EU’s surface area plus Switzerland and Norway holds 60% of the population and represents 72% of the Europe’s GDP), and the centre of the continent’s densest motorway and high-speed train networks. Brussels’ rank among world cities is largely superior to what coul..

Les territoires de l’homosexualité à Bruxelles : visibles et invisibles

À l’image de nombreuses villes occidentales, Bruxelles a récemment vu émerger un quartier gai dans une portion de son espace central, à savoir le quartier Saint-Jacques. Fondé sur des recherches empiriques, cet article veut mettre en lumière la nature de ce nouveau type d’espace d’homosociabilité et à l’inscrire dans une géographie des multiples territoires homosexuels, plus ou moins marqués dans le paysage urbain, à l’échelle de l’ensemble de la ville. La concentration des manifestations les plus visibles de l’homosexualité (par exemple les bars ou associations) au centre-ville, dans le quartier Saint-Jacques en particulier, ne peut masquer une diffusion spatiale à la fois plus large et plus hétérogène d’autres types de territoires homosexuels moins directement visibles dans l’espace urbainBrussels has recently seen the emergence of a Gay Village in an area of the inner city known as the Saint-Jacques district. Based on empirical studies, this article investigates the nature of this new kind of space, increasingly common in Western cities, for homosociability. It also tries to position the phenomenon within a wider geography of homosexual territory on a city-wide scale. The study highlights the contrast between a concentration of visible marks of homosexual presence in the inner city (such as bars and associations), particularly in the Saint-Jacques district, and a wider spatial diffusion of more heterogeneous and less visible types of homosexual territory in urban space

The methyltransferase domain of dengue virus protein NS5 ensures efficient RNA synthesis initiation and elongation by the polymerase domain

International audienceViral RNA-dependent RNA polymerases (RdRps) responsible for the replication of single-strand RNA virus genomes exert their function in the context of complex replication machineries. Within these replication complexes the polymerase activity is often highly regulated by RNA elements, proteins or other domains of multi-domain polymerases. Here, we present data of the influence of the methyltrans-ferase domain (NS5-MTase) of dengue virus (DENV) protein NS5 on the RdRp activity of the polymerase domain (NS5-Pol). The steady-state polymerase activities of DENV-2 recombinant NS5 and NS5-Pol are compared using different biochemical assays allowing the dissection of the de novo initiation, transition and elongation steps of RNA synthesis. We show that NS5-MTase ensures efficient RdRp activity by stimulating the de novo initiation and the elongation phase. This stimulation is related to a higher affinity of NS5 toward the single-strand RNA template indicating NS5-MTase either completes a high-affinity RNA binding site and/or promotes the correct formation of the template tunnel. Furthermore, the NS5-MTase increases the affinity of the priming nucleotide ATP upon de novo initiation and causes a higher catalytic efficiency of the polymerase upon elongation. The complex stimulation pattern is discussed under the perspective that NS5 adopts several conforma-tions during RNA synthesis