Detecting Illegal Arms Trade

Illegal arms are responsible for thousands of deaths in civil wars every year. Yet, their trade is very hard to detect. We propose a method to statistically detect illegal arms trade based on the investor knowledge embedded in financial markets. We focus on eight countries under UN arms embargo in the period 1990-2005, and analyze eighteen events during the embargo that suddenly increase or decrease conflict intensity. If the weapon-making companies are not trading or are trading legally, an event worsening the hostilities should not affect their stock prices or affect them adversely, since it delays the removal of the embargo. Conversely, if the companies are trading illegally, the event may increase stock prices, since it increases the demand for illegal weapons. We detect no significant effect overall. However, we find a large and significant positive reaction for companies head-quartered in countries where the legal and reputation costs of illegal trades are likely to be lower. We identify such countries using measures of corruption and transparency in arms trade. We also suggest a method to detect potential embargo violations based on stock reactions by individual companies, including chains of reactions. The presumed violations are higher for conflicts with more UN investigations and for companies with more Internet stories regarding embargo.

Charge Orbits of Symmetric Special Geometries and Attractors

We study the critical points of the black hole scalar potential $V_{BH}$ in N=2, d=4 supergravity coupled to $n_{V}$ vector multiplets, in an asymptotically flat extremal black hole background described by a 2(n_{V}+1)-dimensional dyonic charge vector and (complex) scalar fields which are coordinates of a special K\"{a}hler manifold. For the case of homogeneous symmetric spaces, we find three general classes of regular attractor solutions with non-vanishing Bekenstein-Hawking entropy. They correspond to three (inequivalent) classes of orbits of the charge vector, which is in a 2(n_{V}+1)-dimensional representation $R_{V}$ of the U-duality group. Such orbits are non-degenerate, namely they have non-vanishing quartic invariant (for rank-3 spaces). Other than the 1/2-BPS one, there are two other distinct non-BPS classes of charge orbits, one of which has vanishing central charge. The three species of solutions to the N=2 extremal black hole attractor equations give rise to different mass spectra of the scalar fluctuations, whose pattern can be inferred by using invariance properties of the critical points of $V_{BH}$ and some group theoretical considerations on homogeneous symmetric special K\"{a}hler geometry.Comment: 63 pages, 9 Tables. v2: typos fixed, Refs. added, accepted for publication in IJMP

The X-ray spectra of the first galaxies: 21cm signatures

The cosmological 21cm signal is a physics-rich probe of the early Universe, encoding information about both the ionization and the thermal history of the intergalactic medium (IGM). The latter is likely governed by X-rays from star-formation processes inside very high redshift (z > 15) galaxies. Due to the strong dependence of the mean free path on the photon energy, the X-ray SED can have a significant impact on the interferometric signal from the cosmic dawn. Recent Chandra observations of nearby, star-forming galaxies show that their SEDs are more complicated than is usually assumed in 21cm studies. In particular, these galaxies have ubiquitous, sub-keV thermal emission from the hot interstellar medium (ISM), which generally dominates the soft X-ray luminosity (with energies < 1 keV, sufficiently low to significantly interact with the IGM). Using illustrative soft and hard SEDs, we show that the IGM temperature fluctuations in the early Universe would be substantially increased if the X-ray spectra of the first galaxies were dominated by the hot ISM, compared with X-ray binaries with harder spectra. The associated large-scale power of the 21cm signal would be higher by roughly a factor of three. More generally, we show that the peak in the redshift evolution of the large-scale (k = 0.2 1/Mpc) 21cm power is a robust probe of the soft-band SED of the first galaxies, and importantly, is not degenerate with their bolometric luminosities. On the other hand, the redshift of the peak constrains the X-ray luminosity and halo masses which host the first galaxies.Comment: 9 pages, 7 figures. Accepted for publication on MNRA

APFEL Web: a web-based application for the graphical visualization of parton distribution functions

We present APFEL Web, a web-based application designed to provide a flexible user-friendly tool for the graphical visualization of parton distribution functions (PDFs). In this note we describe the technical design of the APFEL Web application, motivating the choices and the framework used for the development of this project. We document the basic usage of APFEL Web and show how it can be used to provide useful input for a variety of collider phenomenological studies. Finally we provide some examples showing the output generated by the application.Comment: Final version, matches published version in JPhysG. Web-application available from http://apfel.mi.infn.it

On some properties of the Attractor Equations

We discuss the Attractor Equations of N=2, $d=4$ supergravity in an extremal black hole background with arbitrary electric and magnetic fluxes (charges) for field-strength two-forms. The effective one-dimensional Lagrangian in the radial (evolution) variable exhibits features of a spontaneously broken supergravity theory. Indeed, non-BPS Attractor solutions correspond to the vanishing determinant of a (fermionic) gaugino mass matrix. The stability of these solutions is controlled by the data of the underlying Special K\"{a}hler Geometry of the vector multiplets' moduli space. Finally, after analyzing the 1-modulus case more in detail, we briefly comment on the choice of the K\"{a}hler gauge and its relevance for the recently discussed entropic functional.Comment: 14 pages, to be published in Phys. Lett. B; a misprint in Ref. [13] has been correcte

Treatment decision-making capacity in children and adolescents hospitalized for an acute mental disorder: The role of cognitive functioning and psychiatric symptoms

OBJECTIVE: This study was conducted to assess treatment decision-making capacity (TDMC) in a child and adolescent psychiatric sample and to verify possible associations between TDMC, psychiatric symptom severity, and cognitive functioning. METHODS: Twenty-two consecutively recruited patients hospitalized for an acute mental disorder, aged 11-18 years, underwent measurement of TDMC by the MacArthur Competence Assessment Tool for Treatment (MacCAT-T). The MacCAT-T interview focused on patients' current treatment, which comprised second-generation antipsychotics (45.5%), first-generation antipsychotics (13.6%), antiepileptic drugs used as mood stabilizers or lithium carbonate (45.5%), selective serotonin reuptake inhibitors (32%), and benzodiazepines (18%). We moreover measured cognitive functioning (Wechsler Intelligence Scale for Children III) and psychiatric symptom severity (Brief Psychiatric Rating Scale v 4.0). RESULTS: Patients' TDMC varied within the sample, but MacCAT-T scores were good in the sample overall, suggesting that children and adolescents with severe mental disorders could be competent to consent to treatment. The TDMC proved independent of psychiatric diagnosis while being positively associated with cognitive functioning and negatively with excitement. CONCLUSION: The MacCAT-T proved feasible for measuring TDMC in a child and adolescent psychiatric sample. TDMC in minors with severe mental disorders was not necessarily impaired. These results deserve reconsidering the interplay between minors and surrogate decision-makers as concerning treatment decisions

The chemical evolution of self-gravitating primordial disks

Numerical simulations show the formation of self-gravitating primordial disks during the assembly of the first structures in the Universe, in particular during the formation of Pop.~III and supermassive stars. Their subsequent evolution is expected to be crucial to determine the mass scale of the first cosmological objects, which depends on the temperature of the gas and the dominant cooling mechanism. Here, we derive a one-zone framework to explore the chemical evolution of such disks and show that viscous heating leads to the collisional dissociation of an initially molecular gas. The effect is relevant on scales of 10 AU (1000 AU) for a central mass of 10 M_sun (10^4 M_sun) at an accretion rate of 10^{-1} M_sun yr^{-1}, and provides a substantial heat input to stabilize the disk. If the gas is initially atomic, it remains atomic during the further evolution, and the effect of viscous heating is less significant. The additional thermal support is particularly relevant for the formation of very massive objects, such as the progenitors of the first supermassive black holes. The stabilizing impact of viscous heating thus alleviates the need for a strong radiation background as a means of keeping the gas atomic.Comment: 13 pages, 5 figures, 6 tables, accepted at A&

IL RITORNO DEI MATERIALI NATURALI: NUOVE TENDENZE AUTARCHICHE

La crisi economica ha generato diverse tendenze 'autarchiche' che coinvolgono il progetto con l’utilizzo di materie primordiali, di base e disponibili in natura. Questi materiali di grado 'zero' possono crescere, trasformarsi e rigenerarsi anche in vitro. Si tratta di materiali vivi, di organismi biologici con una sorprendente espressività e 'potenza' di prestazioni, che si fanno portatori di una nuova etica, di autenticità e valori democratici, perché fatti con materiali abbondanti in natura, commestibili o a partire dagli scarti agricoli e rifiuti. Dietro il comune denominatore di estetiche del "primitivo" e dell' 'imperfetto', c’è un processo inversamente proporzionale: a maggiore sofisticatezza tecnologica corrisponde paradossalmente una no-form che esprime una perdita di senso della composizione, del valore della forma

Attractor Horizon Geometries of Extremal Black Holes

We report on recent advances in the study of critical points of the ``black hole effective potential'' V_{BH} (usually named \textit{attractors}) of N=2, d=4 supergravity coupled to n_{V} Abelian vector multiplets, in an asymptotically flat extremal black hole background described by 2n_{V}+2 dyonic charges and (complex) scalar fields which are coordinates of an n_{V}-dimensional Special Kahler manifold