245 research outputs found

    Priority monism and essentiality of fundamentality: a reply to Steinberg

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    Steinberg has recently proposed an argument against Schaffer’s priority monism. The argument assumes the principle of Necessity of Monism, which states that if priority monism is true, then it is necessarily true. In this paper, I argue that Steinberg’s objection can be eluded by giving up Necessity of Monism for an alternative principle, that I call Essentiality of Fundamentality, and that such a principle is to be preferred to Necessity of Monism on other grounds as well

    Multi-GeV Electron Spectrometer

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    The advance in laser plasma acceleration techniques pushes the regime of the resulting accelerated particles to higher energies and intensities. In particular the upcoming experiments with the FLAME laser at LNF will enter the GeV regime with almost 1pC of electrons. From the current status of understanding of the acceleration mechanism, relatively large angular and energy spreads are expected. There is therefore the need to develop a device capable to measure the energy of electrons over three orders of magnitude (few MeV to few GeV) under still unknown angular divergences. Within the PlasmonX experiment at LNF a spectrometer is being constructed to perform these measurements. It is made of an electro-magnet and a screen made of scintillating fibers for the measurement of the trajectories of the particles. The large range of operation, the huge number of particles and the need to focus the divergence present unprecedented challenges in the design and construction of such a device. We will present the design considerations for this spectrometer and the first results from a prototype.Comment: 7 pages, 6 figures, submitted to NIM

    Data augmentation to improve the soundscape ranking index prediction

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    Predicting the sound quality of an environment represents an important task especially in urban parks where the coexistence of sources of anthropic and biophonic nature produces complex sound patterns. To this end, an index has been defined by us, denoted as soundscape ranking index (SRI), which assigns a positive weight to natural sounds (biophony) and a negative one to anthropogenic sounds. A numerical strategy to optimize the weight values has been implemented by training two machine learning algorithms, the random forest (RF) and the perceptron (PPN), over an augmented data-set. Due to the availability of a relatively small fraction of labelled recorded sounds, we employed Monte Carlo simulations to mimic the distribution of the original data-set while keeping the original balance among the classes. The results show an increase in the classification performance. We discuss the issues that special care needs to be addressed when the augmented data are based on a too small original data-set

    First FAMU observation of muon transfer from \u3bcp atoms to higher-Z elements

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    Abstract: The FAMU experiment aims to accurately measure the hyperfine splitting of the ground state of the muonic hydrogen atom. A measurement of the transfer rate of muons from hydrogen to heavier gases is necessary for this purpose. In June 2014, within a preliminary experiment, a pressurized gas-target was exposed to the pulsed low-energy muon beam at the RIKEN RAL muon facility (Rutherford Appleton Laboratory, U.K.). The main goal of the test was the characterization of both the noise induced by the pulsed beam and the X-ray detectors. The apparatus, to some extent rudimental, has served admirably to this task. Technical results have been published that prove the validity of the choices made and pave the way for the next steps. This paper presents the results of physical relevance of measurements of the muon transfer rate to carbon dioxide, oxygen, and argon from non-thermalized excited \u3bcp atoms. The analysis methodology and the approach to the systematics errors are useful for the subsequent study of the transfer rate as function of the kinetic energy of the \u3bcp currently under way

    Gulella io Verdcourt, 1974 and Oxychilus alliarius (Miller, 1822): first reports of two greenhouse snails in Italy (Gastropoda: Streptaxidae, Oxychilidae)

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    Several species new for Italy, including Gulella io and Oxychilus alliarius, were found during surveys on alien slugs and snails in greenhouses of Italian botanical gardens and scientific museums. Gulella io is native to tropical Africa but has been described from specimens collected in European greenhouses since the 1930s. Two shells and living juvenile specimen of this species were collected in 2019 in the Botanical Garden of Padua. Oxychilus alliarius has a wide range in Europe but is absent from Italy: previous records have generally proved to be based on misidentification of other Oxychilus species. Several shells and living specimens were found in 2024 in the Aquarium of Genoa; a bleached shell probably belonging to O. alliarius had previously been found in the Citta Studi Botanical Garden, Milan. Easily transported with plants, this predatory snail has been unwittingly introduced to almost all countries of the world and in some areas is threatening the native fauna. Unlike tropical species, it may escape from greenhouses and acclimatize in Italy, but its impact is likely to be negligible since many members of this genus with a similar ecology are already present and widespread in the country

    A small slug from a tropical greenhouse reveals a new rathouisiid lineage with triaulic tritrematic genitalia (Gastropoda: Systellommatophora)

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    A small slug found in the tropical greenhouse of the Science Museum (MUSE) of Trento (Italy) turned out to be a species of the little-known systellommatophoran family Rathouisiidae. We undertook detailed comparative anatomical and molecular studies using specimens of the MUSE slug, Rathouisia sinensis, and sequences of other systellommatophoran species deposited in GenBank to conduct a systematic and phylogenetic assessment. Analysis of the genitalia of the MUSE slug and R. sinensis revealed an unusual triaulic tritrematic structure: two separate female ducts – one for egg release (oviduct), the other for intake of allosperm (vagina) – and a separate male duct for autosperm release. Analysis of the nucleotide sequences of several mitochondrial (COI, 16S rDNA) and nuclear (18S rDNA, ITS2 flanked by 5.8S and 28S rDNA fragments, H3) gene fragments supported assignation of the MUSE slug to Rathouisiidae, but also its distinction from the other rathouisiid genera Atopos, Granulilimax, Rathouisia and an undescribed genus from the Ryukyu Islands (Japan). Therefore, we decided to describe the MUSE slug as a new species in a new genus: Barkeriella museensis gen. et sp. nov. The species is certainly an alien introduced into the tropical greenhouse of MUSE, but its origin is unknown and calls for further investigation. © 2022 The Linnean Society of London

    Local and regional scale biodiversity patterns of forest snail assemblages in Tuscany (central Italy)

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    The land mollusc faunas of three forest areas of Tuscany (central Italy) were sampled to test the effect of geographical and environmental factors on the structure of biodiversity. A total of 60 sites were surveyed in the years 2009-2011, recording species richness and abundance of snails in 400 m2 plots randomly selected in beech and oak woods. Sampling strategy relied on a combination of visual search and litter analysis. Environmental variables (topsoil pH and altitude) and UTM coordinates were recorded to detect relationships with species richness and number of individuals per plot. Abundance data were analyzed using non-metric multidimensional scaling and canonical correspondence analysis; faunal similarity within and between areas was computed by the Bray Curtis index and snail assemblages of the two forest types were compared. A total of 55 species were recorded, with low values of local richness and abundance per site compared to other forest sites in central and northern Europe. Total richness was similar in the three areas, but composition and local richness varied significantly between them. Geographical factors explained the highest percentage of variance, while habitat type, altitude and pH only accounted for a minor part. Internal similarity was greater than between-area similarity in two out of three areas. Beech forests had richer and more heterogeneous faunas, but lower levels of abundance than oak woods. The results are discussed in terms of historical biogeography and local environmental conditions, and compared with those from similar surveys across Europe
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