Pion Generalized Parton Distributions within a fully covariant constituent quark model

We extend the investigation of the Generalized Parton Distribution for a charged pion within a fully covariant constituent quark model, in two respects: (i) calculating the tensor distribution and (ii) adding the treatment of the evolution, needed for achieving a meaningful comparison with both the experimental parton distribution and the lattice evaluation of the so-called generalized form factors. Distinct features of our phenomenological covariant quark model are: (i) a 4D Ansatz for the pion Bethe-Salpeter amplitude, to be used in the Mandelstam formula for matrix elements of the relevant current operators, and (ii) only two parameters, namely a quark mass assumed to hold $m_q=~220$ MeV and a free parameter fixed through the value of the pion decay constant. The possibility of increasing the dynamical content of our covariant constituent quark model is briefly discussed in the context of the Nakanishi integral representation of the Bethe-Salpeter amplitude.Comment: Pages 20, figure 11 and table 8. Minor changes. To be published in EPJ

Chaotic dynamics in a storage-ring Free Electron Laser

The temporal dynamics of a storage-ring Free Electron Laser is here investigated with particular attention to the case in which an external modulation is applied to the laser-electron beam detuning. The system is shown to produce bifurcations, multi-furcations as well as chaotic regimes. The peculiarities of this phenomenon with respect to the analogous behavior displayed by conventional laser sources are pointed out. Theoretical results, obtained by means of a phenomenological model reproducing the evolution of the main statistical parameters of the system, are shown to be in a good agreement with experiments carried out on the Super-ACO Free Electron Laser.Comment: submitted to Europ Phys. Journ.

Non-Gaussian fluctuations in stochastic models with absorbing barriers

The dynamics of a one-dimensional stochastic model is studied in presence of an absorbing boundary. The distribution of fluctuations is analytically characterized within the generalized van Kampen expansion, accounting for higher order corrections beyond the conventional Gaussian approximation. The theory is shown to successfully capture the non Gaussian traits of the sought distribution returning an excellent agreement with the simulations, for {\it all times} and arbitrarily {\it close} to the absorbing barrier. At large times, a compact analytical solution for the distribution of fluctuations is also obtained, bridging the gap with previous investigations, within the van Kampen picture and without resorting to alternative strategies, as elsewhere hypothesized.Comment: 2 figures, submitted to Phys. Rev. Let

Can a microscopic stochastic model explain the emergence of pain cycles in patients?

A stochastic model is here introduced to investigate the molecular mechanisms which trigger the perception of pain. The action of analgesic drug compounds is discussed in a dynamical context, where the competition with inactive species is explicitly accounted for. Finite size effects inevitably perturb the mean-field dynamics: Oscillations in the amount of bound receptors spontaneously manifest, driven by the noise which is intrinsic to the system under scrutiny. These effects are investigated both numerically, via stochastic simulations and analytically, through a large-size expansion. The claim that our findings could provide a consistent interpretative framework to explain the emergence of cyclic behaviors in response to analgesic treatments, is substantiated.Comment: J. Stat. Mech. (Proceedings UPON2008

Stochastic Turing Patterns on a Network

The process of stochastic Turing instability on a network is discussed for a specific case study, the stochastic Brusselator model. The system is shown to spontaneously differentiate into activator-rich and activator-poor nodes, outside the region of parameters classically deputed to the deterministic Turing instability. This phenomenon, as revealed by direct stochastic simulations, is explained analytically, and eventually traced back to the finite size corrections stemming from the inherent graininess of the scrutinized medium.Comment: The movies referred to in the paper are provided upon request. Please send your requests to Duccio Fanelli ([email protected]) or Francesca Di Patti ([email protected]

Infectious bursal disease virus in free-living wild birds: A systematic review and meta-analysis of its sero-viroprevalence on a global scale

Infectious bursal disease virus (IBDV) is an economically important pathogen for poultry, whereas knowledge of its occurrence in non-poultry hosts is limited. The objective of this systematic review and meta-analysis is to summarize the up-to-date knowledge about the sero-viroprevalence of IBDV in wild birds on a global scale. A computerized literature research was performed on PubMed, Scopus, CAB Direct and Web of Science to find relevant publications, along with the screening of reference lists. Journal articles, book chapters, scientific correspondences, conference proceedings and short communications on IBDV virological and/or serological surveys in free-living wild birds published between 1970 and 2021 were considered as eligible. Among 184 studies found, 36 original contributions met the pre-established criteria. A random-effect model was applied to calculate pooled seroprevalence estimates with 95% confidence intervals, whereas the paucity of virological studies (n = 6) only allowed a qualitative description of the data. The pooled seroprevalence was estimated to be 6% (95% CI: 3%–9%) and a high heterogeneity was detected (I2= 96%). Sub-group analyses were not performed due to the scarcity of available information about hypothetical moderators. With respect to virological studies, IBDV was detected in Anseriformes, Columbiformes, Galliformes, Passeriformes and Pelecaniformes and different strains related to poultry infection were isolated. Our estimates of serological data showed a moderate exposure of wild birds to IBDV. The susceptibility of different species to IBDV infection underlines their potential role in its epidemiology at least as carriers or spreaders. Indeed, the isolation of IBDV in healthy wild birds with a migratory attitude might contribute to a long-distance spread of the virus and to strain diversity. While a wild reservoir host could not be clearly identified, we believe our work provides useful insights for conducting future surveys which are needed to broaden our knowledge of IBDV occurrence in wild birds

Managerial competences in public organisations: The healthcare professionals' perspective

Background: Human resources play a critical role in encouraging efficient performance within organisations, especially for public healthcare organisations, where competences of staff are key aspects of the quality of services provided. In this context, the enhancement of competences are strategic objectives for Human Resources Management (HRM) in order to achieve excellent and lasting results. However, competences of healthcare professionals are both clinical and managerial. This study identifies specific managerial competences perceived as crucial by healthcare professionals in order to improve their performance and develop suitable HRM practices. Methods: The research methodology was divided into three main phases using mixed methods, commencing with literature review to identify the initial framework about managerial competences. Focus groups were then used to discuss evidence from the literature. Feedback from focus groups was used to draft the final questionnaire. Finally, the answers to the questionnaire were analysed through statistical software. Results: The results show that managers and professionals share a view of what specific managerial competences for healthcare organisations should be. Main competences are: Quality evaluation based on outcomes; enhancement of professional competences; programming based on process management; project cost assessment; informal communication style; and participatory leadership. Conclusions: Although the issue of managerial skills in healthcare is widely discussed in literature, findings are often fragmentary. Our work includes a systematic literature review useful for more empirical studies. Furthermore, our results can support public managers who want to set up positive HRM practices for healthcare professionals

Structural assessment of the gripper interlock of the DEMO breeding blanket transporter

The maintenance of the DEMO Breeding Blanket (BB) remotely is a crucial aspect in development of the DEMO power plant. It is a challenge due to the huge mass of the BB segment of about 180 tons. A new concept for the BB transporter has recently been developed. To properly grip and manipulate each BB segment, the BB transporter has been equipped with a gripper interlock. Due to the geometry of the BB and the vacuum vessel, the attachment point on the BB segment is not aligned with its center of gravity. Hence in addition to the vertical lifting load, large moments about the horizontal axes need to be reacted.The work discussed here concerns the structural analysis conducted on the gripper interlock; its structural integrity has been checked against the most severe load conditions that include also seismic loads according to the EN13001. Elastic analyses were performed using a finite element model in accordance with EN 13001-3-1:2012 + A2:2018, Cranes - General Design - Part 3-1: Limit States and proof competence of steel structure. The effect of the gap sizes at the contact surfaces between gripper interlock and BB after engagement as well as the effect of different friction coefficients on the sliding areas were assessed. The improvements of the design based on the structural analysis are presented, too

Lecciana, a new low-vigour olive cultivar suitable for super high density orchards and for nutraceutical evoo production

Cultivar is the key factor for sustainability of the olive super high density planting system (SHD). ‘Lecciana’ is a new olive cultivar for oil production obtained in 1998 by a controlled cross between cv. Arbosana (♀) and cv. Leccino (♂) in a breeding program as part of an international research agreement between Agromillora Iberia S.L.U. and University of Bari. ‘Lecciana’ is the first olive cultivar of Italian descent suitable for SHD, featuring all the vegetative and productive traits required for efficient, sustainable olive growing intensification. Thanks to low vigor, early bearing (3rd year after planting), high yield efficiency (about 0.5 kg of fruits cm−2 of trunk section area) and good fruit size (3.5 g), ‘Lecciana’ could be planted with tree densities over 1,200 trees per hectare for an efficient continuous mechanical harvesting. High frost resistance, very low pistil abortion (3%), high fruit set (3%), oil content (over 19% fw) and, above all, good unsaturated fatty acids profile, polyphenols content (over 450 mg kg−1 ) and fruitiness median are the main distinctive characters of this new cultivar. The oils of ‘Lecciana’ fall into the category ‘nutraceutical EVOOs’ which can benefit from the specific functional health claim