Another unconsidered sinister effect of indusrty-specific crises? On the possible emergence of adverse selection phenomena on the survival of entrepreneurial ventures.

This article explores the possibility that under an intensely negative industry-specific shock, the commonly detected positive relationship between the human capital of founders and the survival prospects of start-up businesses may actually be reversed. Starting from an analysis of the issue from a theoretical perspective in order to derive the necessary and sufficient conditions for the emergence of these adverse selection phenomena in entrepreneurship, the study examines a sample of 179 Italian start-ups operating in the ICT services market created during the boom period from 1995 to early 2000. Econometric analyses provide evidence that, during an intense industry crisis (i.e., early 2000 to 2003), entrepreneurs with a substantial amount of human capital may pursue an exit strategy.High-tech entrepreneurship; Adverse selection; Industry crises.

On the determinants of the degree of openness of Open Source firms: An entry model

This paper examines the relationship between the degree of openness that software start-ups choose and some of the main industrial features faced by new entrants. Hypotheses derived from a formal model are tested through the implementation of econometric techniques and information provided by a novel database (ELISS). Theoretical predictions and empirical results indicate that the choice by start-ups of the degree of openness is negatively influenced by the sensitivity of consumers to price and is positively related both to the strength of network externalities their products exhibit and to the competitive advantage of the incumbent.open-source software; network effects; entry

Conformational Studies by Dynamic NMR. 97.Structure, Conformation, Stereodynamics and Enantioseparation of Aryl Substituted Norbornanes.

CAN 140:163414 AN 2003:996217 CAPLUS (COPYRIGHT (C) 2008 ACS ON SCIFINDER (R)) ABSTRACT THE STRUCTURE OF A 1,7,7-TRIARYLNORBORNANE (I) HAS BEEN DETD. BY X-RAY DIFFRACTION AND WAS FOUND ESSENTIALLY EQUAL TO THAT PREDICTED BY MOL. MECHANICS CALCNS. RESTRICTED ROTATION OF THE ARYL GROUPS ALSO HAS BEEN OBSD. BY DYNAMIC NMR SPECTROSCOPY IN THIS COMPD. AND IN A NO. OF ANALOGOUSLY SUBSTITUTED NORBORNANES. THE ARYL-NORBORNANE BOND ROTATION BARRIERS WERE MEASURED BY LINE SHAPE ANAL. OF THE 13C NMR SPECTRA OBTAINED AT TEMPS. LOWER THAN -100 °C AND WERE FOUND TO COVER THE RANGE 6.0 TO 7.9 KCAL MOL-1. AN EXCEPTION WAS THE ROTATION INVOLVING THE O-ANISYL GROUP IN II, WHICH OCCURS NEAR AMBIENT TEMP. SINCE THE CORRESPONDING BARRIER IS MUCH HIGHER (14.4 KCAL MOL-1). IN ONE CASE (III) CONFIGURATIONAL ENANTIOMERS COULD BE SEPD. BY CHIRAL HPLC AND THE CORRESPONDING CD SPECTRA RECORDED

Migdal effect and photon Bremsstrahlung: improving the sensitivity to light dark matter of liquid argon experiments

The search for dark matter weakly interacting massive particles with noble liquids has probed masses down and below a GeV/c^2. The ultimate limit is represented by the experimental threshold on the energy transfer to the nuclear recoil. Currently, the experimental sensitivity has reached a threshold equivalent to a few ionization electrons. In these conditions, the contribution of a Bremsstrahlung photon or a so-called Migdal electron due to the sudden acceleration of a nucleus after a collision might be sizable. In the present work, we use a Bayesian approach to study how these effects can be exploited in experiments based on liquid argon detectors. In particular, taking inspiration from the DarkSide-50 public spectra, we develop a simulated experiment to show how the Migdal electron and the Bremsstrahlung photon allow to push the experimental sensitivity down to masses of 0.1 GeV/c^2, extending the search region for dark matter particles of previous results. For these masses we estimate the effect of the Earth shielding that, for strongly interacting dark matter, makes any detector blind. Finally, we show how the sensitivity scales for higher exposure.Comment: 30 pages, 13 figures, 2 table

Feasibility and coexistence of large ecological communities

The role of species interactions in controlling the interplay between the stability of ecosystems and their biodiversity is still not well understood. The ability of ecological communities to recover after small perturbations of the species abundances (local asymptotic stability) has been well studied, whereas the likelihood of a community to persist when the conditions change (structural stability) has received much less attention. Our goal is to understand the effects of diversity, interaction strengths and ecological network structure on the volume of parameter space leading to feasible equilibria. We develop a geometrical framework to study the range of conditions necessary for feasible coexistence. We show that feasibility is determined by few quantities describing the interactions, yielding a nontrivial complexity–feasibility relationship. Analysing more than 100 empirical networks, we show that the range of coexistence conditions in mutualistic systems can be analytically predicted. Finally, we characterize the geometric shape of the feasibility domain, thereby identifying the direction of perturbations that are more likely to cause extinctions

Giant g factor tuning of long-lived electron spins in Ge

Control of electron spin coherence via external fields is fundamental in spintronics. Its implementation demands a host material that accommodates the highly desirable but contrasting requirements of spin robustness to relaxation mechanisms and sizeable coupling between spin and orbital motion of charge carriers. Here we focus on Ge, which, by matching those criteria, is rapidly emerging as a prominent candidate for shuttling spin quantum bits in the mature framework of Si electronics. So far, however, the intrinsic spin-dependent phenomena of free electrons in conventional Ge/Si heterojunctions have proved to be elusive because of epitaxy constraints and an unfavourable band alignment. We overcome such fundamental limitations by investigating a two dimensional electron gas (2DEG) confined in quantum wells of pure Ge grown on SiGe-buffered Si substrates. These epitaxial systems demonstrate exceptionally long spin relaxation and coherence times, eventually unveiling the potential of Ge in bridging the gap between spintronic concepts and semiconductor device physics. In particular, by tuning spin-orbit interaction via quantum confinement we demonstrate that the electron Land\'e g factor and its anisotropy can be engineered in our scalable and CMOS-compatible architectures over a range previously inaccessible for Si spintronics

Survey on broiler pre-slaughter mortality in a commercial abattoir of central Italy

The pre-slaughter mortality was investigated on broilers, in the Mediterranean climate condition, considering the most significant risk factors as the journey length, waiting time, season and the space allowance in cages. At first, the pre-slaughter mortality was studied considering the totality of birds and then by examining in detail three broiler categories: large, medium and small size. The average dead on arrival (DOA) recorded on the totality of birds throughout the year was 0.38% and the values obtained in winter, spring, summer and autumn were 0.52, 0.48, 0.31 and 0.22%, respectively. The mortality rate observed during the year was 0.52, 0.47 and 0.31% for large, medium and small broilers, respectively. In all three groups, the maximum values of mortality were obtained in winter, whereas the minimum ones were recorded in autumn, spring and summer for large, medium, and small size birds, respectively. The increase of journey length could cause a higher mortality rate whereas the increase of the waiting time in the facilities at controlled environmental conditions did not seem to be a risk factor, but rather a mean to reduce the number of dead animals (all P < 0.05). It is concluded that the resistance to the hostile weather conditions, long journeys and extended waiting times was strongly related with the body weight of broilers; therefore, the planning of the slaughtering activity should consider this aspect, in order to avoid animal suffering and the economic loss

Il tirocinio integrato dei futuri maestri: Dall'esperienza sperimentale diretta (TDDI) alle competenze digitali nei percorsi indiretti (TIDI)

Il tirocinio ha rappresentato a lungo l’elemento costante nella formazione iniziale degli insegnanti di scuola Primaria. Il Corso di Studi in …, a partire dall’Anno Accademico 2020-2021 ha sperimentato e validato un nuovo modello di tirocinio digitale integrato (TDDI), che ha arricchito ulteriormente la formazione dei futuri insegnanti. Nella fase successiva il Corso di Studi ha promosso poi un nuovo modello di accompagnamento indiretto dell’esperienza di stage curricolare, denominato tirocinio indiretto digitale integrato (TIDI) in cui una quota oraria è destinata allo sviluppo di competenze digitali correlate agli specifici standard professionali dei maestri

Welfare indicators during broiler slaughtering

1. The aim of this study was to identify the most relevant welfare indicators for unloading, lairage, stunning, killing and post-mortem inspection in a poultry slaughter plant. Different indicators were unloading duration, lairage time, environmental variables in the lairage facilities, shackling time and electrical variables used in the water bath. 2. Lairage time did not correlate strongly with dead on arrival. Heat stress was limited by means of ventilation systems, correct cage placement and appropriate stocking density per crate. The acceptable shackling period was about 30 s. 3. The presence of a corneal reflex showed that an animal was alive, while spontaneous wing flapping, spontaneous eye blinking and response to a painful stimulus were regarded as indicators of stunning efficiency. 4. It was concluded that the presence of recent traumatic injuries during the post-mortem inspection could be a valid means to establish whether corrective measures concerning the handling, transport and loading procedures should be taken