184 research outputs found
Corrigendum
No full textDiagnostic challenges in low-grade central osteosarcoma: a retrospective study
Published online 1 January 2024 at https://boneandjoint.org.uk/Article/10.1302/0301-620X.106B1.BJJ2023-0531.R1 and in Bone Joint J. 2024;106-B(1):
99–106.
The author Costantino Errani’s name was incorrectly given as “Constantino Errani” in the January 2024
published version.
The correct version is now online
Tidal evolution of dwarf spheroidal galaxies and dark matter subhalos
No full textUnderstanding the distribution of dark matter (DM) on galactic scales is at the root of constraining the nature of DM and processes of galaxy formation like baryonic feedback. Dwarf spheroidal galaxies (dSphs), lying at the faintest end of the galaxy luminosity function, are the most DM dominated systems known to date. They are a promising candidates to probe the DM distribution on kpc scales. In this work, we study the tidal evolution, abundance and observable properties of dSphs embedded in DM subhaloes.
Tidal evolution of subhaloes and dwarf galaxies
We run controlled simulations of the tidal evolution of a single cold dark matter subhalo with a centrally-divergent density cusp, tailored to follow the evolution of the subhalo for arbitrarily large fractions of tidally stripped mass. Based on simple dynamical arguments and numerical experiments, we argue that cuspy DM subhaloes cannot be completely disrupted by smooth tidal fields. Using a model of the Tucana III dSph galaxy as an example, we show that tides can strip dSph galaxies down to sub-solar luminosities. The remnant micro-galaxies would appear as co-moving groups of metal-poor, low-mass stars of similar age, embedded in sub-kpc DM subhaloes.
Subhalo depletion driven by the galactic disc
To further quantify the abundance of subhaloes in Milky Way-like galaxies containing a galactic disc, we use high-resolution re-simulations of all subhaloes of the Aquarius A2 merger tree with masses M > 10^8 Msol at accretion. We model the tidal evolution of subhaloes with both cuspy and cored DM profiles, finding that cuspy models have twice as many surviving subhaloes within the virial radius of the host at redshift z=0 as their cored counterparts. The presence of a galactic disc reduces the number of surviving subhaloes further by a factor of < 2 for subhaloes on orbits that pass through the disc.
Mass estimates for Milky Way dwarf galaxies
With the aim of comparing observed properties of Milky Way dSph galaxies to simulations, we construct an estimator for enclosed masses based on the virial theorem, insensitive to anisotropy in the velocity dispersion and tailored to yield masses with minimum uncertainty introduced by our ignorance on (i) the shape of the inner DM profile, and (ii) how deeply the stellar component is embedded within the subhalo. Tests against controlled simulations show that the estimator provides unbiased masses with an accuracy of ~10 per cent. Application to published kinematic data of Milky Way dSph galaxies reveals a tight correlation between enclosed mass and luminosity. Comparison against cuspy and cored DM haloes extracted from controlled cosmological simulations shows that the high mass densities of ultrafaint galaxies are not compatible with large DM cores, and that the (total) halo masses of the classical Milky Way dSph galaxies span a remarkably narrow range (8 < log10 M/Msol < 10) at present, showing no clear trend with either galaxy size or luminosity
Radiation detection properties of 4H-SiC Schottky diodes irradiated up to 10(16) n/cm(2) by 1 MeV neutrons
No full textWe report the results of an experimental study on the radiation hardness of 4H-SiC diodes used as alpha-particle detectors with 1 MeV neutrons up to a fluence of 8 x 10(15) n/cm(2). As the irradiation level approaches the range 10(15) n/cm(2), the material behaves as intrinsic due to a very high compensation effect and the diodes are still able to detect with a reasonable good Charge Collection Efficiency (CCE = 80%).For fluences > 10(15) n/cm(2) CCE decreases monotonically to approximate to 20 % at the highest fluence. Heavily irradiated SiC diodes have been studied, by means of Photo Induced Current Transien
Giovanni Boccaccio biografo "ravennate" di Dante
No full textIl saggio si concentra sulla precoce fortuna editoriale della biografia dantesca del Boccaccio, e specie sullo straordinario omaggio all'ultimo rifugio ravennate, posto in sapiente contrasto con l'invettiva antifiorentina, che connotava l'appassionata prima stesura del "Trattatello in laude di Dante"
Fertility problems in cv. Antonio Errani: stigma pollen interaction.
No full textCultivar "Antonio Errani", selected in 1975 by our Department, was recently introduced in different cultivation areas in Italy. This cultivar is endowed with noteworthy organoleptic and commercial characteristics, but in some environments it is affected by poor and irregular fruiting. In the present study, some aspects of the floral biology of this variety were studied, in order to investigate possible causes of this infertility. Research focused on observation of compatibility and morphological analysis of the micro-gametophyte (characterization of pollen grain shape, viability and germination ability) and the macro-gametophyte (morpho-anatomic analysis of stigma structure by Scanning Electron Microscope observations). Directly on the stigmatic surface, observations were also carried out on pollen-pistil interaction, pollen retention on the stigma and germination ability. Moreover the pollen tube elongation in the style up to the ovary was observed. Results showed no anomaly involving the micro-gametophyte. Self-compatibility of the variety was confirmed, but poor pollen retention on the stigma was found, together with slow elongation of the pollen tube up to the ovary. Scanning Electron Microscope observations revealed early degeneration of stigmatic papillae, which were seen to be collapsed and therefore unable to retain pollen grains
Deep Levels in 4H Silicon Carbide Epilayers Induced by Neutron-Irradiation up to 1016 n/cm2
No full textPorous Tantalum implants in tumor surgery of the pelvis and lower extremities
No full textPorous Tantalum implants in tumor surgery of the pelvis and lower extremitie
Desarthrodesis and Prosthetic reconstruction of the knee after resection of bone tumors
No full textDesarthrodesis and Prosthetic reconstruction of the knee after resection of bone tumor
Corso di insegnamento SITOP: “Inquadramento clinico ed epidemiologico delle neoplasie muscoloscheletriche dell’età pediatrica”
No full textInquadramento clinico ed epidemiologico delle neoplasie muscoloscheletriche dell’età pediatric
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