Neutrino pair annihilation (ννˉ→e−e+\nu{\bar \nu}\to e^-e^+) in the presence of quintessence surrounding a black hole

Quintessence fields, introduced to explain the speed-up of the Universe, might affect the geometry of spacetime surrounding black holes, as compared to the standard Schwarzschild and Kerr geometries. In this framework, we study the neutrino pairs annihilation into electron-positron pairs ($\nu{\bar \nu}\to e^-e^+$) near the surface of a neutron star, focusing, in particular, on the Schwarzschild-like geometry in presence of quintessence fields. The effect of the latter is to increase the minimum photon-sphere radius ($R_{ph}$), increasing in such a way the maximum energy deposition rate near to $R_{ph}$. The rate turns out to be several orders of magnitude greater than the rate computed in the framework of General Relativity. These results might provide an efficient mechanism for the generation of GRBs and lead to constraints on the parameters of the quintessence model.Comment: 22 pages, 8 figure

Some observations on the morphology of Sclerasterias richardi a rarely encountered Mediterranean Sea star (Echinodermata: Asteriidae)

The presence of specimens of the asteroid Sclerasterias richardi(Perrier, 1882) in Maltese waters,with some new details of its morphology (observed by SEM) and with special reference to its madreporites,is reported

Glove-based systems for medical applications: review of recent advancements

Human hand motion analysis is attracting researchers in the areas of neuroscience, biomedical engineering, robotics, human-machines interfaces (HMI), human-computer interaction (HCI), and artificial intelligence (AI). Among the others, the fields of medical rehabilitation and physiological assessments are suggesting high impact applications for wearable sensing systems. Glove-based systems are one of the most significant devices in assessing quantities related to hand movements. This paper provides updated survey among the main glove solutions proposed in literature for hand rehabilitation. Then, the process for designing glove-based systems is defined, by including all relevant design issues for researchers and makers. The main goal of the paper is to describe the basics of glove-based systems and to outline their potentialities and limitations. At the same time, roadmap to design and prototype the next generation of these devices is defined, according to the results of previous experiences in the scientific community

Mesophotic and Deep-Sea Vulnerable Coral Habitats of the Mediterranean Sea: Overview and Conservation Perspectives

Although the different communities distributed in the mesophotic and deep waters play a fundamental role in the functioning of the marine ecosystems, the assessment of their global distribution is still far to be achieved. This is also true in the Mediterranean Sea, where exploration technologies are revealing a large diversity of unknown communities structured totally or partially by corals, which represent vulnerable marine ecosystems (VMEs) according to FAO’s guidelines. This chapter aims to define and describe the main coral habitats of the mesophotic and aphotic zones of the Mediterranean, such as coralligenous formations, cold-water coral frameworks, coral forests and sea pen fields. The role of these habitats in providing benefit for a variety of invertebrates and fishes as well as a suite of ecosystem goods and services is highlighted. Fishing is one of the main anthropogenic impacts affecting Mediterranean coral habitats, and the current conservation measures are often ineffective. Ongoing attempts and future solutions aiming at the conservation of these VMEs are here discussed, including the fishing restriction in strategic areas characterized by lush coral communities, the implementation of controls against illegal fishery, the development of encounter protocols for vulnerable species and the use of observers onboard

Astrophysical neutrino oscillations after pulsar timing array analyses

The pattern of neutrino flavor oscillations could be altered by the influence of noisy perturbations such as those arising from a gravitational wave background (GWB). A stochastic process that is consistent with a GWB has been recently reported by the independent analyses of pulsar timing array (PTA) data sets collected over a decadal timescale by the North American Nanohertz Observatory for Gravitational Waves (NANOGrav), the European Pulsar Timing Array (EPTA), the Parkes Pulsar Timing Array (PPTA), and the Chinese Pulsar Timing Array (CPTA) collaborations. We investigate the modifications in the neutrino flavor oscillations under the influence of the GWB reported by the PTA collaborations and we discuss how such effects could be potentially revealed in near-future neutrino detectors, possibly helping the discrimination of different models for the GWB below the nHz frequency range.Comment: 5 pages, 2 figure

Spread of the non-indigenous ascidian Aplidium accarense (Millar, 1953) in the Eastern Mediterranean Sea: morphological and molecular tools for an accurate identification

The aplousobranch ascidian Aplidium accarense (Millar, 1953) was first described on the western coast of Africa, where it is considered native. Afterwards, this species was introduced along south-American Atlantic coasts, where it affected local shellfish farms through a massive colonization of both natural and artificial substrata. Aplidium accarense has been recently reported along Catalan coasts and in the Tyrrhenian Seas (Western Mediterranean) where it represents a non-indigenous species, only recorded in harbours and aquaculture farms thus far. These Mediterranean records support the hypothesis that A. accarense is currently expanding within the basin, representing a potential invasive species. In this study, several colonies of A. accarense were found for the first time on artificial substrata within the semi-enclosed basin of the Mar Piccolo of Taranto (Italy, Ionian Sea), in the Eastern Mediterranean. Here we provide an updated description of A. accarense combining both morphological and molecular approaches, in order to allow an accurate and reliable identification of this expanding species. Comparing the morphology of the specimens collected from Taranto with the previous descriptions, a slight intra-specific variability has been noticed. Therefore, we provide detailed comparisons of the specimens found in Taranto with all the other A. accarense sampled in other areas of the world, in order to highlight the intra-species variability. The correct identification of a potentially-dangerous species such as A. accarense, represents a needed step for environmental monitoring purposes and for implementing management strategies to mitigate the effects of non-indigenous species on natural ecosystems and human activities

Il processo all'avvelenatrice di Smirne, il principio di concentrazione e il rinvio a cent'anni

Durata ragionevole, diritto di difesa, principio di legalità offrono chiavi di lettura utili per districarsi anche nei processi appartenenti alla storia forense meno recente. L’Autore impiega questi principi per esaminare le vicende di un processo celebrato durante il I secolo a.C., nel quale la difficoltà della decisione induce i magistrati a non decidere, rinviando il processo a cent’anni

Polyclinum constellatum (Tunicata, Ascidiacea), an emerging non-indigenous species of the Mediterranean Sea: integrated taxonomy and the importance of reliable DNA barcode data

Polyclinum constellatum is a colonial ascidian with a pantropical distribution, recently introduced into the Eastern Mediter-ranean Sea, indeed it was reported along Egyptian and Turkish coasts in 2016 and 2018, respectively. In the present study we report its presence along the coasts of Greece and Italy (Eastern and Central Mediterranean Sea, respectively), using an integrated approach combining morphological and molecular analysis. Colonies of P. constellatum were collected from artificial substrata in the harbour of Taranto (Ionian Sea) in November 2018 and in the marina of Heraklion (Crete, Aegean Sea) in October 2019. Remarkably, several colonies observed and collected in the Heraklion marina appeared as two or more masses joined at their base or fused together, often with different colour morpho-types. Here we provide their detailed morphological description and molecular characterization using a long fragment of the mitochondrial COI sequence as a DNA barcode. Furthermore, we present and discuss a comparative table of the main morphological features of all species of the genus Polyclinum known to date and an accurate analysis of the reliability of the Polyclinum COI sequence currently available. Our study proves that P. constellatum is further spreading in the Eastern Mediterranean Sea and has already reached the Central Mediterranean Sea. Moreover, the pres-ent study reveals the presence of erroneously assigned Polyclinum COI sequences in public databases and a possible synonymy between the species P. constellatum, Polyclinum indicum Sebastian, 1954 (accepted as Polyclinum sebastiani Brunetti, 2007) and Polyclinum madrasensis Sebastian, 1952. Overall, our data provide a useful tool for the accurate and reliable identification of this expanding species in other non-investigated areas and suggest the most likely vector of introduction of this non-indigenous species in the investigated localities