612 research outputs found
Spin glasses on Bethe Lattices for large coordination number
We study spin glasses on random lattices with finite connectivity. In the
infinite connectivity limit they reduce to the Sherrington Kirkpatrick model.
In this paper we investigate the expansion around the high connectivity limit.
Within the replica symmetry breaking scheme at two steps, we compute the free
energy at the first order in the expansion in inverse powers of the average
connectivity (z), both for the fixed connectivity and for the fluctuating
connectivity random lattices. It is well known that the coefficient of the 1/z
correction for the free energy is divergent at low temperatures if computed in
the one step approximation. We find that this annoying divergence becomes much
smaller if computed in the framework of the more accurate two steps breaking.
Comparing the temperature dependance of the coefficients of this divergence in
the replica symmetric, one step and two steps replica symmetry breaking, we
conclude that this divergence is an artefact due to the use of a finite number
of steps of replica symmetry breaking. The 1/z expansion is well defined also
in the zero temperature limit.Comment: 17 pages and 6 figure
Anderson transition on the Bethe lattice: an approach with real energies
We study the Anderson model on the Bethe lattice by working directly with
propagators at real energies . We introduce a novel criterion for the
localization-delocalization transition based on the stability of the population
of the propagators, and show that it is consistent with the one obtained
through the study of the imaginary part of the self-energy. We present an
accurate numerical estimate of the transition point, as well as a concise proof
of the asymptotic formula for the critical disorder on lattices of large
connectivity, as given in [P.W. Anderson 1958]. We discuss how the forward
approximation used in analytic treatments of localization problems fits into
this scenario and how one can interpolate between it and the correct asymptotic
analysis.Comment: Close to published versio
Profit Shifting by Debt Financing in Europe
This article aims at analyzing the link between subsidiariesâ capital structure and taxation in Europe. First we introduce a trade-off model, which studies a MNCsâ financial strategy and shows how debt policy allows multinational groups to shift profits from low-tax to high-tax jurisdictions. By letting the MNC choose both leverage and the percentage of profit shifting, we depart from the relevant literature which has mainly focused on the latter. Using the AMADEUS dataset we show that: i) subsidiariesâ leverage increases with the statutory tax rate, levied in the country where it operates; ii) this positive effect is lower, the higher the parent company tax rate is. Furthermore, an increase in the parent companyâs tax rate is estimated to raise its subsidiariesâ leverage.capital structure, default, multinationals, profit shifting, taxation
Mothers and Workers in the Time of COVID-19: Negotiating Motherhood within Smart Working
The article is an autoethnographic account written by three Italian academic
researchers and mothers with children of different ages. The authors engage
in a reflection starting with their experience as working women committed
to the workâfamily negotiation process while facing the COVID-19 health
emergency that has affected the whole world. This article focuses on how
we, as middle-class, heterosexual, white mothers working in a privileged
employment context during the period of the pandemic lockdown, negotiated
the complex mother and worker roles, balancing work and family time while
smart working (teleworking from home). We start with a reflection on the
use of autoethnography as a research tool and then propose an analysis of
workâfamily balance strategies in an anomalous situation, such as that of
the lockdown, highlighting the tensions in gender roles within dual-career
families
Cancerogenic parasites in veterinary medicine: a narrative literature review
Parasite infection is one of the many environmental factors that can significantly contribute to carcinogenesis and is already known to be associated with a variety of malignancies in both human and veterinary medicine. However, the actual number of cancerogenic parasites and their relationship to tumor development is far from being fully understood, especially in veterinary medicine. Thus, the aim of this review is to investigate parasite-related cancers in domestic and wild animals and their burden in veterinary oncology. Spontaneous neoplasia with ascertained or putative parasite etiology in domestic and wild animals will be reviewed, and the multifarious mechanisms of protozoan and metazoan cancer induction will be discussed
Italyâs ACE Tax and Its Effect on a Firmâs Leverage
This article describes the new ACE-type system implemented in Italy since 2012. The authors first show that this system reduces but does not eliminate the financial distortion due to interest deductibility. Using a dataset of Italian companies, the authors analyze the impact of this relief on Italian firm capital structure. Despite the permanence of a tax advantage and its gradual implementation, the ACE relief is estimated to reduce significantly leverage. By decreasing default risk it is also expected to reduce systemic risk
Excitability of the motor cortex in patients with migraine changes with the time elapsed from the last attack
BACKGROUND:
Motor-evoked potentials (MEPs) produced by single-pulse transcranial magnetic stimulation (TMS) of the motor cortex can be an objective measure of cortical excitability. Previously, MEP thresholds were found to be normal, increased, or even reduced in patients with migraine. In the present study, we determined whether the level of cortical excitability changes with the time interval from the last migraine attack, thereby accounting for the inconsistencies in previous reports.
METHODS:
Twenty-six patients with untreated migraine without aura (MO) underwent a MEP study between attacks. Their data were then compared to the MEP data collected from a group of 24 healthy volunteers (HVs). During the experiment, the TMS figure-of-eight coil was positioned over the left motor area. After identifying the resting motor threshold (RMT), we delivered 10 single TMS pulses (rate: 0.1 Hz, intensity: 120% of the RMT) and averaged the resulting MEP amplitudes.
RESULTS:
The mean RMTs and MEP amplitudes were not significantly different between the MO and HV groups. In patients with MO, the RMTs were negatively correlated with the number of days elapsed since the last migraine attack (rhoâ=â-0.404, pâ=â0.04).
CONCLUSION:
Our results suggest that the threshold for evoking MEPs is influenced by the proximity of an attack; specifically, the threshold is lower when a long time interval has passed after an attack, and is higher (within the range of normative values) when measured close to an attack. These dynamic RMT variations resemble those we reported previously for visual and somatosensory evoked potentials and may represent time-dependent plastic changes in brain excitability in relation to the migraine cycle
Care Tasks and New Routines for Italian Families during the COVID-19 Pandemic: Perspectives from Women
The lockdown management during the COVID-19 pandemic has been very complex for families. The present study is part of a broader interdisciplinary research and follows the gender perspective, which has made it possible to bring a focus on the pandemic starting with women who, within family dynamics, have suffered most from the effects of the lockdown, having to manage multiple roles simultaneously and in the same place. The data were collected through an on-line survey. The aim is to understand how family routines were structured during the lockdown and how womenâs emotional regulation developed during this period. Moreover, a further area of investigation focused on the distribution of domestic work and childcare among partners and on the relationships between smart working and the family dimension. The participants are 300 women living in different Italian region. The data highlights how during lockdown women with children have more regulatory and relational routines than women without children and that during this period both regulatory and relational routines become less consistent. It also emerges that women perceive that they dedicate more time to domestic activities and childcare than their partners do anthe effects of the lockdown, having to manage multiple roles simultaneously and in the same place. The data were collected through an on-line survey. The aim is to understand how family routines were structured during the lockdown and how womenâs emotional regulation developed during this period. Moreover, a further area of investigation focused on the distribution of domestic work and childcare among partners and on the relationships between smart working and the family dimension. The participants are
300 women living in different Italian region. The data highlights how during lockdown women with children have more regulatory and relational routines than women without children and that during this period both regulatory and relational routines become less consistent. It also emerges that women perceive that they dedicate more time to domestic activities and childcare than their partners do and that the time dedicated to childcare is greater in the 0-6 year range. Moreover, it emerges clearly how reconciling the smart working with the family dimension is not always easy
Prospective multicentre Italian pregnancy cohort study (SIMPLE) on the associations of maternal first trimester SIMPLE nutritional score with early placental function markers and pregnancy outcomes
Currently, the adherence to nutritional guidelines is low, with alarming rates of obesity worldwide and micronutrient deficiencies documented even in industrialised countries. As a consequence, nutritional screening and counselling represent a critical subject in early pregnancy, aiming to improve pregnancy outcomes and population health
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