3. Discrimination, Othering, and the Political Instrumentalizing of Pandemic Disease

The complex history of pandemics has created a diversified array of anti-epidemic responses, which have allowed structures of authority to express their power in multiple ways. In this paper, by considering theories applicable to cases ranging from Europe to Asia, from the 11th to the 18th century, we conduct a comparative analysis capable of identifying common traits and radical differences, aiming to show how such deployment of power was not always commensurate with the medical theories of the age, and with the gravity of the epidemiological situation. Specifically, we analyse how Western European States, in their process of formation, employed the concept of ‘public health’ to create the grounds for an unprecedented exercise of power over the private sphere. Furthermore, we compare this attitude with the discrimination of the minority known as burakumin in Japan, which was destined to undertake any ‘dirty’ or ‘impure’ occupation, to preserve the immunity of the community. In other words, we examine how structures of power have exploited states of exception to implement control measures beyond the needs of the situation through an increasingly hypertrophic apparatus of security; and ways in which political authorities have not aligned with medical or philosophical authorities of their times, for opportunistic reasons that benefited their own social, religious, or racial group. Keywords: Pandemics, Discrimination, Immunity, Purity, Burakumi

Experimental value of the specific surface energy of the cleavage 10.4 calcite rhombohedron in the presence of its saturated aqueous solution

In this study, we describe a method to obtain experimental values of the surface energy of calcite. A zenithal imaging device was used to acquire pictures of droplets of CaCO3 saturated aqueous solution on the surface of a calcite crystal sample. Pictures were used to measure the contact angle between the droplets and the {10.4} calcite surfaces. The method is discussed along with its geometrical ground, as well as the theoretical foundation of the contact angle calculation. A comparison is made with the literature data; a good agreement is found between our experimental values and those obtained from the more recent ab initio calculations

Deep learning nonlocal and scalable energy functionals for quantum Ising models

Density functional theory (DFT) is routinely employed in material science and in quantum chemistry to simulate weakly correlated electronic systems. Recently, deep learning (DL) techniques have been adopted to develop promising functionals for the strongly correlated regime. DFT can be applied to quantum spin models too, but functionals based on DL have not been developed yet. Here, we investigate DL-based DFTs for random quantum Ising chains, both with nearest-neighbor and up to next-nearest neighbor couplings. Our neural functionals are trained and tested on data produced via the Jordan-Wigner transformation, exact diagonalization, and tensor-network methods. An economical gradient-descent optimization is used to find the ground-state properties of previously unseen Hamiltonian instances. Notably, our non-local functionals drastically improve upon the common local density approximations, and they are designed to be scalable, allowing us to simulate chain sizes much larger than those used for training. The prediction accuracy is analyzed, paying attention to the spatial correlations of the learned functionals and to the role of quantum criticality. Our findings indicate a suitable strategy to extend the reach of other computational methods with a controllable accuracy.Comment: 14 pages, 15 figure

Plot-based urbanism and urban morphometrics : measuring the evolution of blocks, street fronts and plots in cities

Generative urban design has been always conceived as a creation-centered process, i.e. a process mainly concerned with the creation phase of a spatial transformation. We argue that, though the way we create a space is important, how that space evolves in time is ways more important when it comes to providing livable places gifted by identity and sense of attachment. We are presenting in this paper this idea and its major consequences for urban design under the title of “Plot-Based Urbanism”. We will argue that however, in order for a place to be adaptable in time, the right structure must be provided “by design” from the outset. We conceive urban design as the activity aimed at designing that structure. The force that shapes (has always shaped) the adaptability in time of livable urban places is the restless activity of ordinary people doing their own ordinary business, a kind of participation to the common good, which has hardly been acknowledged as such, that we term “informal participation”. Investigating what spatial components belong to the spatial structure and how they relate to each other is of crucial importance for urban design and that is the scope of our research. In this paper a methodology to represent and measure form-related properties of streets, blocks, plots and buildings in cities is presented. Several dozens of urban blocks of different historic formation in Milan (IT) and Glasgow (UK) are surveyed and analyzed. Effort is posed to identify those spatial properties that are shared by clusters of cases in history and therefore constitute the set of spatial relationships that determine the morphological identity of places. To do so, we investigate the analogy that links the evolution of urban form as a cultural construct to that of living organisms, outlining a conceptual framework of reference for the further investigation of “the DNA of places”. In this sense, we identify in the year 1950 the nominal watershed that marks the first “speciation” in urban history and we find that factors of location/centrality, scale and street permeability are the main drivers of that transition towards the entirely new urban forms of contemporary cities

Discovery of Broad Soft X-ray Absorption Lines from the Quasar Wind in PDS 456

High resolution soft X-ray spectroscopy of the prototype accretion disk wind quasar, PDS 456, is presented. Here, the XMM-Newton RGS spectra are analyzed from the large 2013-2014 XMM-Newton campaign, consisting of 5 observations of approximately 100 ks in length. During the last observation (hereafter OBS. E), the quasar is at a minimum flux level and broad absorption line profiles are revealed in the soft X-ray band, with typical velocity widths of $\sigma_{\rm v}\sim 10,000$ km s$^{-1}$. During a period of higher flux in the 3rd and 4th observations (OBS. C and D, respectively), a very broad absorption trough is also present above 1 keV. From fitting the absorption lines with models of photoionized absorption spectra, the inferred outflow velocities lie in the range $\sim 0.1-0.2c$. The absorption lines likely originate from He and H-like neon and L-shell iron at these energies. Comparison with earlier archival data of PDS 456 also reveals similar absorption structure near 1 keV in a 40 ks observation in 2001, and generally the absorption lines appear most apparent when the spectrum is more absorbed overall. The presence of the soft X-ray broad absorption lines is also independently confirmed from an analysis of the XMM-Newton EPIC spectra below 2 keV. We suggest that the soft X-ray absorption profiles could be associated with a lower ionization and possibly clumpy phase of the accretion disk wind, where the latter is known to be present in this quasar from its well studied iron K absorption profile and where the wind velocity reaches a typical value of 0.3$c$.Comment: 44 pages, including 13 figures, accepted for publication in The Astrophysical Journa

Short term X-ray spectral variability of the quasar PDS 456 observed in a low flux state

We present an analysis of the 2013 Suzaku campaign on the nearby luminous quasar PDS 456, covering a total duration of ~1 Ms and a net exposure of 455 ks. During these observations, the X-ray flux was suppressed by a factor of >10 in the soft X-ray band when compared to other epochs. We investigated the broadband continuum by constructing a spectral energy distribution, making use of the optical/UV photometry and hard X-ray spectra from the later XMM-Newton/NuSTAR campaign in 2014. The high energy part of this low flux state cannot be accounted for by self-consistent accretion disc and corona models without attenuation by absorbing gas, which partially covers a substantial fraction of the line of sight towards the X-ray source. Two absorption layers are required, of column density $\log (N_{\rm{H,low}}/{\rm cm^{-2}})=22.3\pm0.1$ and $\log (N_{\rm{H,high}}/{\rm cm^{-2}})=23.2\pm0.1$, with average covering factors of ~80% (with typical 5% variations) and 60% ($\pm$10-15%), respectively. In these observations PDS 456 displays significant short term X-ray spectral variability, on timescales of ~100 ks, which can be accounted for by variable covering of the absorbing gas. The partial covering absorber prefers an outflow velocity of $v_{\rm pc} = 0.25^{+0.01}_{-0.05}c$ at the >99.9% confidence level over the case where $v_{\rm pc}=0$. This is consistent with the velocity of the highly ionised outflow responsible for the blueshifted iron K absorption profile. We therefore suggest that the partial covering clouds could be the denser, or clumpy part of an inhomogeneous accretion disc wind. Finally we estimate the size-scale of the X-ray source from its variability. The radial extent of the X-ray emitter is found to be of the order ~15-20 $R_{\rm g}$, although the hard X-ray (>2 keV) emission may originate from a more compact or patchy corona of hot electrons, which is ~6-8 $R_{\rm g}$ in size.Comment: 38 pages, 13 figures, accepted for publication in MNRA

Anne Finch Conway (1631-1679)

Pienamente inserita all’interno del ricco panorama culturale del Seicento inglese, Anne Conway (nata Finch) è una delle figure chiave all’interno della transizione dal neoplatonismo rinascimentale all’idealismo settecentesco. All’interno di questo percorso intellettuale si situa un netto rifiuto delle due correnti filosofiche prevalenti nel suo ambiente, vale a dire il dualismo di matrice cartesiana e il materialismo di Hobbes. Per contro, la filosofia di Conway opera un sincretismo originale e unico tra fonti diverse, incluse tradizioni di natura religiosa quali la Kabbalah ebraica e la spiritualità quacchera, per proporre una critica radicale al monismo panteista e al materialismo meccanicistico. La sua difesa dell’alterità divina, della semplicità mereologica di Dio e dell’incompatibilità di questa semplicità con l’eventuale materialità di Dio o la sua mutabilità si cristallizzano nell’elaborazione filosofica della monade come principio attivo. Per contro, Conway elabora invece un pensiero che vede nella comune radice spiritualista l’unica difesa possibile del monismo, e nella purificazione attraverso la sofferenza l’orizzonte essenziale della morale e della teleologia. Dal punto di vista metafisico, la teoria di maggior importanza proposta da Conway consiste in un monismo spiritualista, che unifica tutte le forme dell’essere nella loro comune origine spirituale, e che vede la materia come un risultato del peccato originale e della caduta. La comune origine di ogni cosa, tuttavia, non si riduce ad un monismo singolarista, che identificherebbe Dio e le creature. Conway, invece, difende una teoria triadica dell’essere, distinguendo Dio (colui che non ammette cambiamento) da Cristo (colui che ammette cambiamento, ma solo in direzione ameliorativa), ed entrambi dal creato e dalle creature (che ammettono cambiamento sia in senso positivo che negativo). Questa complessa nozione di cambiamento viene sviluppata, secondo Conway, in relazione alla giustizia distributiva dell’elemento divino, ed è dunque connessa a concezioni etiche dell’organizzazione metafisica del reale. Fedele al proprio impianto di base platonico, Conway associa la caduta degli spiriti alla loro trasmutazione in corpi, e ne prevede un escatologico esito spirituale, a sua volta garantito dalla giustizia divina e dalla loro trasformazione etic

La formula di Kubo: aspetti non perturbativi dalla superconduttivita'

The Kubo formula can be used to discuss the Meissner effect for quantum systems of particles and electromagnetic field, within the framework of a semiclassical approximation (the Kubo analysis). We discuss the general properties of the Kubo formula, for an infinitely extended system of particles in external field. Using the continuity equation, together with euclidean covariance and gauge invariance of the Kubo response function, we show that superconductivity is reduced to the study of the response to a magnetic field localized on the boundary of some large region. Thus, superconductors are characterized by long range correlations, which correspond to a singularity at low momenta of the Kubo response function. For relativistic systems, the additional use of the spectral condition allows us to demonstrate that the presence of the singularity (a nonlocal term) is equivalent to the presence, in the mass spectrum of matter, of a massless Goldstone mode. We discuss this result, also in comparison with the interpretations of superconductivity as a broken symmetry, especially with S. Weinberg's analysis. Next we discuss the foundation and consistency of the Kubo analysis. We show that it can be derived by combining two approximations: a variational ansatz, which approximates the vacuum as a product state of matter and electromagnetic field, and the linear response theory, to further approximate the particle current to first order in the electromagnetic field. This approach turns out to be compatible with the nonperturbative characters of superconductivity with respect to the e.m. coupling, which is essential for the generation of a photon mass

Accelerating equilibrium spin-glass simulations using quantum annealers via generative deep learning

Adiabatic quantum computers, such as the quantum annealers commercialized by D-Wave Systems Inc., are routinely used to tackle combinatorial optimization problems. In this article, we show how to exploit them to accelerate equilibrium Markov chain Monte Carlo simulations of computationally challenging spin-glass models at low but finite temperatures. This is achieved by training generative neural networks on data produced by a D-Wave quantum annealer, and then using them to generate smart proposals for the Metropolis-Hastings algorithm. In particular, we explore hybrid schemes by combining single spin-flip and neural proposals, as well as D-Wave and classical Monte Carlo training data. The hybrid algorithm outperforms the single spin-flip Metropolis-Hastings algorithm. It is competitive with parallel tempering in terms of correlation times, with the significant benefit of a much shorter equilibration time.Comment: 24 pages, 7 figure