HART EFFECT AND EQUILIBRIUM IN INCOMPLETE MARKETS I

In this paper I reconsider the problem of the existence for GEI models. It is well known that existence for this kind of models can fail since there are bad spot prices. Using tools from Algebraic Geometry I show that the set of bad spot prices is tipically empty if the information tree, the number of secruities and the number of tradable goods at each node satisfy a well defined inequality. Even if such inequality is not staisfied I show that the set of bad spot price can be fully characterized and described using an algorithm and I give an universal bound for the cardinality of this set. Moreover, using these results, I prove that the equilibrium always exists for all endowment profiles.

Incomplete markets with no Hart points

We provide a geometric test of whether a general equilibrium incomplete markets (GEI) economy has Hart points---points at which the rank of the securities payoff matrix drops. Condition (H) says that, at each nonterminal node, there is an affine set (of appropriate dimension) that intersects all of a well-specified set of convex polyhedra. If the economy has Hart points, then Condition (H) is satisfied; consequently, if condition (H) fails, the economy has no Hart points. The shapes of the convex polyhedra are determined by the number of physical goods and the dividends of the securities, but are independent of the endowments and preferences of the agents. Condition (H) fails, and thus there are no Hart points, in interesting classes of economies with only short-lived securities, including economies obtained by discretizing an economy with a continuum of states and sufficiently diverse payoffs.Incomplete Markets, GEI model, Hart points

Implementation of an online information system for the “Flora Critica d’Italia”

Since the early 2000s, within the Italian Botanical Society was discussed the opportunity to realize collaboratively a modern Flora articulated in monographs on the model of others under construction or recently completed in several European countries (1). This initiative had a milestone in 2007 with the institution of the “Fondazione per la Flora Italiana”, with the aim of supporting the activities of study, conservation and cultural and scientific enhancement of the flora of Italy and of sensitizing the national community about the many functions that it implements, in the context of natural and semi-natural ecosystems. The “Foundation for the Italian flora” is responsible for the publication of the "Flora critica d’Italia". During the course of the project, it became apparent the diminishing impact of the hard copy in favour of an online information system more flexible and upgradeable and thus more suited to the current needs of the research but also in all fields of everyday life. Last 25th February the first 3 contributions, concerning the families of Isoetaceae, Heliotropiaceae and Hydrophyllaceae (2, 3, 4) have been published online (http://www.floraditalia.it/index.php? page=flora_critica). These early contributions were prepared in the traditional way with a text editor. In order to create the online information system, under the indications of the Editorial Committee, the Board of Directors decided to rely on the experience gained by the staff of Palermo in the field of biological databases (5, 6) and to support by itself the development of a specific software. It is currently under construction and implementation a relational database that serves as a base for the entire project. It include information related to nomenclature, taxonomy, description, keys, distribution, images, karyology, uses, vernacular names, etc. Data and tables are standardized according to TDWG (Taxonomic Database Working Group) standards (http://www.tdwg.org) and comply with the The Global Biodiversity Information Facility (GBIF) data architecture. The system is composed by two main parts: a database and a web application. The database currently contains 16 relations (although more will be built within the end of the project) and relies onto MySQL Database Management System. The web application is built using PHP scripting language and the CakePHP framework for the server-side part, running on a Linux server. The client-side part leverages onto Javascript and Jquery library. It follows the MVC1 (Model View Controller) design paradigm. It deals with the database manipulation in terms of data management and data presentation along with user management. The whole system addresses several main security issues such as passwords hashing, accesses logging and code injection protections. Data inputting is online by a web browser. The authors will input data in user friendly forms or to import tables. Outputs produced include online ones coming from queries and pdf production to be done periodically to fix what done or to prepare chapters of the volumes to be eventually printed and included in a hard copy volume

Market Clearing and Derivative Pricing.

We develop a method of assigning unique prices to derivative securities, including options, in the continuous-time finance models developed in Raimondo [45] and Anderson and Raimondo [6]. In contrast with the martingale method of valuing options, which cannot distinguish among infinitely many possible option pricing processes for a given underlying securities price process when markets are dynamically incomplete, our option prices are uniquely determined in equilibrium as a function of the underlying economic data and the underlying securities price process; in the single-agent model, this function is given in closed form.

The distance to NGC1316 (Fornax A): yet another curious case

The distance of NGC1316, the brightest galaxy in Fornax, is an interesting test for the cosmological distance scale. First, because Fornax is the 2nd largest cluster of galaxies at <~25 Mpc after Virgo and, in contrast to Virgo, has a small line-of-sight depth; and second, because NGC1316 is the galaxy with the largest number of detected SNeIa, giving the opportunity to test the consistency of SNeIa distances internally and against other indicators. We measure SBF mags in NGC1316 from ground and space-based imaging data, providing a homogeneous set of measurements over a wide wavelength interval. The SBF, coupled with empirical and theoretical calibrations, are used to estimate the distance to the galaxy. We present the first B-band SBF measurements of NGC1316 and use them together with the optical and near-IR SBF data to analyze the properties of field stars. Our distance modulus m-M=31.59 +-0.05(stat) +-0.14(sys), when placed in a consistent Cepheid distance scale, agrees with the results from other indicators. However, our result is ~17% larger than the most recent estimate based on SNeIa. Possible explanations for this disagreement are the uncertainties on internal extinction, or calibration issues. Concerning the stellar population analysis, we confirm earlier results from other indicators: the field stars in NGC1316 are dominated by a solar metallicity, intermediate age component. A substantial mismatch exists between B-band SBF models and data, a behavior that can be accounted for by an enhanced percentage of hot horizontal branch stars. Our study of the SBF distance to NGC1316, and the comparison with distances from other indicators, raises some concern about the homogeneity between the calibrations of different indicators. If not properly placed in the same reference scale, significant differences can occur, with dramatic impact on the cosmological distance ladder.Comment: 21 pages, 13 figures; A&A accepte

Structural and biochemical insights of CypA and AIF interaction

The Cyclophilin A (CypA)/Apoptosis Inducing Factor (AIF) complex is implicated in the DNA degradation in response to various cellular stress conditions, such as oxidative stress, cerebral hypoxia-ischemia and traumatic brain injury. The pro-apoptotic form of AIF (AIF(Δ1-121)) mainly interacts with CypA through the amino acid region 370-394. The AIF(370-394) synthetic peptide inhibits complex formation in vitro by binding to CypA and exerts neuroprotection in a model of glutamate-mediated oxidative stress. Here, the binding site of AIF(Δ1-121) and AIF(370-394) on CypA has been mapped by NMR spectroscopy and biochemical studies, and a molecular model of the complex has been proposed. We show that AIF(370-394) interacts with CypA on the same surface recognized by AIF(Δ1-121) protein and that the region is very close to the CypA catalytic pocket. Such region partially overlaps with the binding site of cyclosporin A (CsA), the strongest catalytic inhibitor of CypA. Our data point toward distinct CypA structural determinants governing the inhibitor selectivity and the differential biological effects of AIF and CsA, and provide new structural insights for designing CypA/AIF selective inhibitors with therapeutic relevance in neurodegenerative diseases

Process of pyroplastic shaping for special-purpose porcelain stoneware tiles

A novel technique to manufacture special-purpose tiles (i.e. trim pieces, steps, skirting boards, etc.) has been recently developed on the basis of a pyroplastic shaping of porcelain stoneware tiles. This innovative process involves a second firing, peaking at temperatures close to those of sintering, whose effect was investigated by comparing industrially-manufactured tiles before and after pyroplastic shaping. Characterization by XRF, XRPD, SEM and standard testing (ISO 10545) put in evidence that pyroplastic bending induced little changes in the water absorption and bulk density values, as in phase composition. Limited variations occurring to closed porosity, mechanical strength and microstructure do not significantly affect the overall technological performance of the special-purpose tiles, which is substantially the same of the original porcelain stoneware tiles. A detailed microstructural characterization was performed for the first time on porcelain stoneware tiles: coarse grains (>10 ?m) represent 10-15% of total volume, while fine-grained crystals, dispersed in the glassy phase, amount from 30% to 65% of the viscous matrix. The pyroplastic behaviour was found to depend in a complex way on such microstructural and compositional features, which deeply affect the effective viscosity of the matrix

XXVII International Congress of Psychology, Estocolmo, 2000 : Simposio "Information and Cognition Information and Creativity"

Contiene los resúmenes de: Information and cognition, information and creativity / Dr. Horacio J. A. Rimoldi ; Information and inference as combined cognitive processes / Dr. Alfredo O. López Alonso ; The influence and use of person factors in the interpretation of test scores / Dr. Gary K. Burger ; Toward a systemic and informational theory of medical diagnostic process / Dr. Roberto Raimond

Towards a Model-Based Field-Frequency Lock for Fast-Field Cycling NMR

Fast-field cycling nuclear magnetic resonance (FFC NMR) relaxometry allows to investigate molecular dynamics of complex materials. FFC relaxometry experiments require the magnetic field to reach different values in few milliseconds and field oscillations to stay within few ppms during signal acquisition. Such specifications require the introduction of a novel field-frequency lock (FFL) system. In fact, control schemes based only on current feedback may not guarantee field stability, while standard FFLs are designed to handle very slow field fluctuations, such as thermal derives, and may be ineffective in rejecting faster ones. The aim of this work is then to propose a methodology for the synthesis of a regulator that guarantees rejection of field fluctuations and short settling time. Experimental trials are performed for both model validation and evaluation of the closed-loop performances. Relaxometry experiments are performed to verify the improvement obtained with the new FFL. The results highlight the reliability of the model and the effectiveness of the overall approach