Female entrepreneurship in perspective: a methodological issue

A methodological approach to the concept of female entrepreneurship concept has not yet been treated: is female entrepreneurship an individual or collective concept? Is it considered a social or natural variable? The purpose of this research is to clear up these alternatives, which are preparatory questions for any research into female entrepreneurship that wishes to measure its features and effects. The article starts with the proposal of an identification procedure, necessary to identifying the variables of female entrepreneurship. It proceeds by classifying the concept of female entrepreneurship into four different modes and discussing their characteristics. The originality of this research consists in its fourfold classification of the concept of female entrepreneurship, intended as a preparatory step prior to the analysis of its characteristics and measures

Financial Sophistication and the Distribution of the Welfare Cost of Inflation

The welfare cost of anticipated inflation is quantified in a calibrated model of the U.S. economy that exhibits tractable equilibrium dispersion in wealth and earnings. Inflation does not generate large losses in societal welfare, yet its impact varies noticeably across segments of society depending also on the financial sophistication of the economy. If money is the only asset, then inflation hurts mostly the wealthier and more productive agents, while those poorer and less productive may even benefit from inflation. The converse holds in a more sophisticated financial environment where agents can insure against consumption risk with assets other than money.money, heterogeneity, friedman rule, trade frictions, calibration

Efficient Monetary Allocations and the Illiquidity of Bonds.

We construct a monetary economy with heterogeneity in discounting and consumption risk. Agents can insure against this risk with both money and nominal government bonds, but all trades must be monetized. We demonstrate that a deflationary policy a la Friedman cannot sustain the efficient allocation. The reason is that no-arbitrage imposes a stringent bound on the return money can pay. The efficient allocation can be sustained when bonds have positive yields and – under certain conditions – only if they are illiquid. Illiquidity – meaning bonds cannot be transformed into consumption as efficiently as cash – is necessary to eliminate arbitrage opportunities.Money ; Heterogeneity ; Friedman Rule ; Illiquid Assets

Evaluation of the strain-line patterns in a human left ventricle: A simulation study

The aim of this paper is to emphasise the role of the primary strain-line patterns in a human left ventricle (LV) within the complex system that is the heart. In particular, a protocol is proposed for the measurement of the principal strain lines (PSL) in the walls of the LV; this protocol is tested by means of a computational model which resembles a human LV. When the analysis is focused on the epicardial surface, PSL can be used to derive information on the directions of muscle fibres during the entire cardiac cycle, not only the systolic phase. © 2013 Taylor & Francis

Monetary Equilibrium and the Cost of Banking Activity

We investigate the effects of banks’ operating costs on allocations and welfare in a low interest rate environment. We introduce an explicit production function for banks in a microfounded model where banks employ labor resources, hired on a competitive market, to run their operations. In equilibrium, this generates a spread between interest rates on loans and deposits, which naturally reflects the underlying monetary policy and the efficiency of financial intermediation. In a deflation or low inflation environment, equilibrium deposits yield zero returns. Hence, banks end up soaking up labor resources to offer deposits that do not outperform idle balances, thus reducing aggregate efficiency

X-ray study of a sample of FR0 radio galaxies: unveiling the nature of the central engine

FR0s are compact radio sources that represent the bulk of the Radio-Loud (RL) AGN population, but they are still poorly understood. Pilot studies on these sources have been already performed at radio and optical wavelengths: here we present the first X-ray study of a sample of 19 FR0 radio galaxies selected from the SDSS/NVSS/FIRST sample of Best & Heckman (2012), with redshift $\leq$ 0.15, radio size $\leq$ 10 kpc and optically classified as low-excitation galaxies (LEG). The X-ray spectra are modeled with a power-law component absorbed by Galactic column density with, in some cases, a contribution from thermal extended gas. The X-ray photons are likely produced by the jet as attested by the observed correlation between X-ray (2-10 keV) and radio (5 GHz) luminosities, similar to FRIs. The estimated Eddington-scaled luminosities indicate a low accretion rate. Overall, we find that the X-ray properties of FR0s are indistinguishable from those of FRIs, thus adding another similarity between AGN associated with compact and extended radio sources. A comparison between FR0s and low luminosity BL Lacs, rules out important beaming effects in the X-ray emission of the compact radio galaxies. FR0s have different X-ray properties with respect to young radio sources (e.g. GPS/CSS sources), generally characterized by higher X-ray luminosities and more complex spectra. In conclusion, the paucity of extended radio emission in FR0s is probably related to the intrinsic properties of their jets that prevent the formation of extended structures, and/or to intermittent activity of their engines.Comment: Accepted for publication in MNRAS (18 pages, 4 figures

Comminution Effects on Mineral-Grade Distribution: The Case of an MVT Lead-Zinc Ore Deposit

Every mining operation is followed by a beneficiation process aimed at delivering quality materials to the transformation industry. Mainly, in order to separate valuable minerals from gangue in mineral processing, the crushing and grinding of extracted ore are crucial operations for the following separation steps. Comminution is the most energy-consuming operation in mining, and the quality of the results is strictly related to the characteristic of the material under treatment, the type of equipment used in comminution, and the circuit design adopted. A preliminary study was performed in order to understand the crushing behavior under different comminution forces of a high-grade mixed Zn-Pb sulfide ore sample, collected in a Mississippi-Valley Type (MVT) deposit, and the distribution of the target minerals among the products of the process. Ore samples were examined and characterized through thin section observation and SEM analyses for the determination of grain size and texture features, while X-ray powder diffraction (XRPD) quantitative analyses were performed for the definition of target mineral concentrations of comminuted product samples. The selected crushing and grinding circuit comprised lab-scale equipment. For each stage of the process, products below the estimated free-grain size threshold were collected, and particle size analyses were carried out. Comminution products were divided into size distribution classes suitable for further separation operations, and XRPD analyses showed a mineral-grade distribution varying with the dimensions of the products. Characterization of the ore material after crushing and grinding force applications in terms of the distribution of target minerals among different-sized classes was achieved. The important trends highlighted should be considered for further investigation related to an efficient separation

Magnetic Nanoparticle Imaging: Insight on the Effects of Magnetic Interactions and Hysteresis of Tracers

The dynamic properties of magnetite nanoparticles are investigated by rate equations with the aim of clarifying the factors affecting their performance as tracers in magnetic particle imaging (MPI). It is shown that size-dependent effects such as magnetic hysteresis and dipole-dipole interaction may have a great impact on the behavior of MPI tracers. Usually, magnetic imaging exploits the higher-order harmonics of the magnetization waveform without considering either intraparticle hysteresis or interparticle interactions. These assumptions may result in an incorrect estimate (either by excess or by defect) of the nanoparticle concentration, which is the ultimate aim of MPI. The mismatch between real and estimated values is apparent for concentrations typical of some therapeutic applications of magnetic nanoparticles or reached by effect of particle accumulation in organs because of slow clearance processes. We show that this difficulty can be removed by measuring not only the magnitude of the third harmonic of the signal but also the phase shift with respect to the driving field. The proposed technique of signal adjustment makes use of the settings of present-day MPI operating devices. The validity of the adjustment procedure is checked by a proof of concept using nonuniform nanoparticle concentrations