Meno misteri nelle viscere del vulcano

La frontiera della ricerca della geofisica moderna si fonda in maniera rilevante su due direttrici al crocevia tra scienza e tecnologia: il progresso tecnologico nella strumentazione per le misure e l'affinamento della capacità di gestione ed elaborazione delle informazioni raccolte. Come in ogni altra scienza sperimentale, i dati e la capacità di saperli analizzare rappresentano pilastri fondamentali nella ricerca geofisica. Allo stato attuale l'Europa è messa a confronto con l'impressionante sviluppo che sta avvenendo in Paesi quali Giappone e Usa. Un esempio significativo è rappresentato dalla campagna di misure sull'isola di Tenerife, alle Canarie, a opera dell'Istituto Nazionale di Geofisica e Vulcanologia presieduto da Enzo Boschi e il Consejo Superior de Investigaciones Cientificas spagnolo. Il grande vulcano Teide, che domina l'isola e che è giudicato dagli esperti "ad alto rischio", è stato investigato con una tecnica di rilevamento innovativa, chiamata aeromagnetismo. Per svelare i segreti dell'edificio vulcanico sottomarino, fin dentro la crosta terrestre, gli scienziati hanno operato dal cielo, a bordo di un elicottero attrezzato con apparati di alta tecnologia sospesi in una sorta di missile che al suo interno ospita i sensori che captano i campi magnetici delle rocce vulcaniche. I rilievi aeromagnetici effettuati consentiranno di identificare le strutture sepolte, in modo tale da ricostruire formazioni come condotti lavici, crateri e faglie. Un contributo (non solo a beneficio della geofisica ma anche della Protezione Civile spagnola) che è stato realizzato con una tecnologia avanzata, fiore all'occhiello dell'Italia e dell'Istituto Nazionale di Geofisica e Vulcanologia. Si tratta inoltre di un esempio estremamente interessante, di cooperazione tra istituzioni italiane ed europee che risulta affiancato da un protocollo ministeriale tra Italia, Spagna e Portogallo realizzato nel 2005 con il sostegno della Fondazione Cotec. La fisica dei terremoti e dei fenomeni vulcanici non soltanto non rispetta le frontiere nazionali coinvolgendo spesso Paesi limitrofi ma (si pensi ai grandi mercati primari e secondari di assicurazione) ne coinvolge in maniera tanto pervasiva le economie da richiedere risposte di impegno e coordinamento di statura europea

Nonlinear dispersion relation in anharmonic periodic mass-spring and mass-in-mass systems

The study of wave propagation in chains of anharmonic periodic systems is of fundamental importance to understand the response of dynamical absorbers of vibrations and acoustic metamaterials working in nonlinear regime. Here, we derive an analytical nonlinear dispersion relation for periodic chains of anharmonic mass-spring and mass-in-mass systems resulting from considering the hypothesis of weak anharmonic energy and a periodic distribution function as ansatz of a general solution of the nonlinear equations of motion. Numerical simulations show that this expression is valid for anharmonic potential energy up to 50% of the harmonic one. This work provides a simple tool to design and study nonlinear dynamics for a class of seismic metamaterials.Comment: 18 pages, 5 figure

No Longer Playing \u3cem\u3eNevils\u3c/em\u3e Advocate: The Ninth Circuit Constricts Appellate Review for Insufficiency of Evidence Claims

On March 19, 2010, the U.S Court of Appeals for the Ninth Circuit in United States v. Nevils held that a reviewing court hearing criminal appeals on the grounds of insufficient evidence must resolve all factual conflicts in favor of the prosecution and ask only if any rational juror could have found the defendant guilty beyond a reasonable doubt. This decision makes it more difficult for the Ninth Circuit to reverse criminal convictions and ultimately preserves the jury’s proper role as the trier of fact

How American Are American Depositary Receipts? ADRs Rule 10B-5 Suits, and \u3cem\u3eMorrison v. National Australia Bank\u3c/em\u3e

Over the previous several decades, federal courts employed two tests—the conduct test and effects test—to determine whether a securities fraud suit with foreign elements was sufficiently connected to the United States to proceed in American courts. In its 2010 decision in Morrison v. National Australia Bank Ltd, the U.S. Supreme Court held that only domestic transactions may be subject to securities fraud suits. The Court then created a bright-line test to determine which transactions were domestic. Unfortunately, the Court’s resultant “transactional test” was not the model of clarity that it hoped to be. In particular, American Depositary Receipts (“ADRs”) frustrate the Court’s quest for clarity because, as foreign securities attempting to transform themselves into domestic securities, they occupy a borderland that is difficult to reconcile with Morrison’s transactional test. This Note analyzes the reasoning of Morrison as well as the district court cases that have implemented the Court’s transactional test. Based on these cases, this Note argues that the determination of whether the purchase and sale of ADRs qualifiy as domestic transactions should depend on the extent to which the issuer has purposefully entered the U.S. market and its regulatory system

Guideline on management of the acute asthma attack in children by Italian Society of Pediatrics.

BACKGROUND: Acute asthma attack is a frequent condition in children. It is one of the most common reasons for emergency department (ED) visit and hospitalization. Appropriate care is fundamental, considering both the high prevalence of asthma in children, and its life-threatening risks. Italian Society of Pediatrics recently issued a guideline on the management of acute asthma attack in children over age 2, in ambulatory and emergency department settings. METHODS: The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) methodology was adopted. A literature search was performed using the Cochrane Library and Medline/PubMed databases, retrieving studies in English or Italian and including children over age 2 year. RESULTS: Inhaled ß2 agonists are the first line drugs for acute asthma attack in children. Ipratropium bromide should be added in moderate/severe attacks. Early use of systemic steroids is associated with reduced risk of ED visits and hospitalization. High doses of inhaled steroids should not replace systemic steroids. Aminophylline use should be avoided in mild/moderate attacks. Weak evidence supports its use in life-threatening attacks. Epinephrine should not be used in the treatment of acute asthma for its lower cost / benefit ratio, compared to β2 agonists. Intravenous magnesium solphate could be used in children with severe attacks and/or forced expiratory volume1 (FEV1) lower than 60% predicted, unresponsive to initial inhaled therapy. Heliox could be administered in life-threatening attacks. Leukotriene receptor antagonists are not recommended. CONCLUSIONS: This Guideline is expected to be a useful resource in managing acute asthma attacks in children over age 2

An alternative 3D inversion method for magnetic anomalies with depth resolution

This paper presents a new method to invert magnetic anomaly data in a variety of non-complex contexts when a priori information about the sources is not available. The region containing magnetic sources is discretized into a set of homogeneously magnetized rectangular prisms, polarized along a common direction. The magnetization distribution is calculated by solving an underdetermined linear system, and is accomplished through the simultaneous minimization of the norm of the solution and the misfit between the observed and the calculated field. Our algorithm makes use of a dipolar approximation to compute the magnetic field of the rectangular blocks. We show how this approximation, in conjunction with other correction factors, presents numerous advantages in terms of computing speed and depth resolution, and does not affect significantly the success of the inversion. The algorithm is tested on both synthetic and real magnetic datasets

Looking for imprints of the first stellar generations in metal-poor bulge field stars

© 2016 ESO. Context. Efforts to look for signatures of the first stars have concentrated on metal-poor halo objects. However, the low end of the bulge metallicity distribution has been shown to host some of the oldest objects in the Milky Way and hence this Galactic component potentially offers interesting targets to look at imprints of the first stellar generations. As a pilot project, we selected bulge field stars already identified in the ARGOS survey as having [Fe/H] 1 and oversolar [α/Fe] ratios, and we used FLAMES-UVES to obtain detailed abundances of key elements that are believed to reveal imprints of the first stellar generations. Aims. The main purpose of this study is to analyse selected ARGOS stars using new high-resolution (R ∼ 45 000) and high-signal-tonoise (S=N > 100) spectra. We aim to derive their stellar parameters and elemental ratios, in particular the abundances of C, N, the α-elements O, Mg, Si, Ca, and Ti, the odd-Z elements Na and Al, the neutron-capture s-process dominated elements Y, Zr, La, and Ba, and the r-element Eu. Methods. High-resolution spectra of five field giant stars were obtained at the 8 m VLT UT2-Kueyen telescope with the UVES spectrograph in FLAMES-UVES configuration. Spectroscopic parameters were derived based on the excitation and ionization equilibrium of Fe i and Fe ii. The abundance analysis was performed with a MARCS LTE spherical model atmosphere grid and the Turbospectrum spectrum synthesis code. Results.We confirm that the analysed stars are moderately metal-poor (-1:04≤[Fe/H]≤-0:43), non-carbon-enhanced (non-CEMP) with [C/Fe] ≤+0:2, and α-enhanced.We find that our three most metal-poor stars are nitrogen enhanced. The α-enhancement suggests that these stars were formed from a gas enriched by core-collapse supernovae, and that the values are in agreement with results in the literature for bulge stars in the same metallicity range. No abundance anomalies (Na-O, Al-O, Al-Mg anti-correlations) were detected in our sample. The heavy elements Y, Zr, Ba, La, and Eu also exhibit oversolar abundances. Three out of the five stars analysed here show slightly enhanced [Y/Ba] ratios similar to those found in other metal-poor bulge globular clusters (NGC 6522 and M 62). Conclusions. This sample shows enhancement in the first-to-second peak abundance ratios of heavy elements, as well as dominantly s-process element excesses. This can be explained by different nucleosynthesis scenarios: (a) the main r-process plus extra mechanisms, such as the weak r-process; (b) mass transfer from asymptotic giant branch stars in binary systems; (c) an early generation of fast-rotating massive stars. Larger samples of moderately metal-poor bulge stars, with detailed chemical abundances, are needed to better constrain the source of dominantly s-process elements in the early Universe

Galactic Archeology with 4MOST

4MOST is a new wide-field, high-multiplex spectroscopic survey facility for the VISTA telescope of ESO. Starting in 2022, 4MOST will deploy more than 2400 fibres in a 4.1 square degree field-of-view using a positioner based on the tilting spine principle. In this ontribution we give an outline of the major science goals we wish to achieve with 4MOST in the area of Galactic Archeology. The 4MOST Galactic Archeology surveys have been designed to address long-standing and far-reaching problems in Galactic science. They are focused on our major themes: 1) Near-field cosmology tests, 2) Chemo-dynamical characterisation of the major Milky Way stellar components, 3) The Galactic Halo and beyond, and 4) Discovery and characterisation of extremely metal-poor stars. In addition to a top-level description of the Galactic surveys we provide information about how the community will be able to join 4MOST via a call for Public Spectroscopic Surveys that ESO will launch.Comment: To be published in "Rediscovering our Galaxy", IAU Symposium 334, Eds. C. Chiappini, I. Minchev, E. Starkenburg, M. Valentin

Galactic Archaeology with CoRoT and APOGEE: Creating mock observations from a chemodynamical model

In a companion paper, we have presented the combined asteroseismic-spectroscopic dataset obtained from CoRoT lightcurves and APOGEE infra-red spectra for 678 solar-like oscillating red giants in two fields of the Galactic disc (CoRoGEE). We have measured chemical abundance patterns, distances, and ages of these field stars which are spread over a large radial range of the Milky Way's disc. Here we show how to simulate this dataset using a chemodynamical Galaxy model. We also demonstrate how the observation procedure influences the accuracy of our estimated ages.Comment: 5 pages, 6 figures. To appear in Astronomische Nachrichten, special issue "Reconstruction the Milky Way's History: Spectroscopic surveys, Asteroseismology and Chemo-dynamical models", Guest Editors C. Chiappini, J. Montalb\'an, and M. Steffe