Microstructure and chemical composition of Roman orichalcum coins emitted after the monetary reform of Augustus (23 B.C.)

A collection of ancient Roman orichalcum coins, i.e., a copper-zinc alloy, minted under the reigns from Caesar to Domitianus, have been characterised using scanning electron microscopy (SEM-EDS) and electron microprobe analysis (EMPA). We studied, for the first time, coins emitted by Romans after the reforms of Augustus (23 B.C.) and Nero (63-64 A.D). These coins, consisting of asses, sestertii, dupondii and semisses, were analysed using non- and invasive analyses, aiming to explore microstructure, corrosive process and to acquire quantitative chemical analysis. The results revealed that the coins are characterized by porous external layers, which are affected by dezincification and decuprification processes. As pictured by the X-ray maps, the elemental distribution of Cu and Zn shows patterns of depletion that in some cases penetrate in deep up to 1 mm. The composition of the un-corroded nucleus is a Cu-Zn alloy containing up to 30% of Zn, typical of coins produced via cementation process

Local Spatio-Temporal Representation Using the 3D Shearlet Transform (STSIP)

In this work we address the problem of analyzing video sequences and of representing meaningful space-time points of interest by using the 3D shearlet transform. We introduce a local representation based on shearlet coe cients of the video, regarded as 2D+T signal. This representation turns out to be informative to understand the local spatio-temporal characteristics, which can be easily detected by an unsupervised clustering algorithm

On the Effects of Sender-Receiver Concealment Mismatch on Multimedia Communication Optimization

A large number of performance optimization algorithms for multimedia communications, including rate-distortion optimized schemes, rely on knowing the decoder behavior in case of data loss, i.e., the decoder-side error concealment technique. However, for the specific case of video coding, standards do not specify it, thus different decoders may - and typically do - use different concealment techniques. This work investigates the impact of assuming, in the transmission optimization phase, a concealment algorithm different from the one that is actually used by the decoder, in order to determine which are the best assumptions to use at the transmitter. Firstly, we investigate the typical performance provided by ten concealment techniques belonging to three widely used algorithmic families (spatial, temporal and mixed). Then, we assess the impact that an incorrect concealment assumption causes, in terms of both packet transmission policy changes and video quality degradation, using a simple rate-distortion transmission optimization technique that targets a generic two QoS-level network. Simulation results over several standard video sequences show that the performance impact of incorrectly assuming the decoder-side concealment technique may be significant but it is limited if the two techniques belong to the same algorithmic family. Moreover, the impact on performance caused by incorrect assumptions is strongly mitigated if the decoder employs a high-performance concealment algorithm. Finally, the impact on the performance of several parameters such as the encoding pattern, the packet loss statistics (uniform and burst losses) and the amount of high-priority traffic is evaluated, showing that the conclusions can be confidently applied to actual multimedia communication scenarios

Understanding neural networks with reproducing kernel Banach spaces

Characterizing the function spaces corresponding to neural networks can provide a way to understand their properties. In this paper we discuss how the theory of reproducing kernel Banach spaces can be used to tackle this challenge. In particular, we prove a representer theorem for a wide class of reproducing kernel Banach spaces that admit a suitable integral representation and include one hidden layer neural networks of possibly infinite width. Further, we show that, for a suitable class of ReLU activation functions, the norm in the corresponding reproducing kernel Banach space can be characterized in terms of the inverse Radon transform of a bounded real measure, with norm given by the total variation norm of the measure. Our analysis simplifies and extends recent results in [43, 34, 35]

Impairment of the autophagic flux in astrocytes intoxicated by trimethyltin

Autophagy is a lysosomal catabolic route for protein aggregates and damaged organelles which in different stress conditions, such as starvation, generally improves cell survival. An impairment of this degradation pathway has been reported to occur in many neurodegenerative processes. Trimethyltin (TMT) is a potent neurotoxin present as an environmental contaminant causing tremors, seizures and learning impairment in intoxicated subjects. The present data show that in rat primary astrocytes autophagic vesicles (AVs) appeared after few hours of TMT treatment. The analysis of the autophagic flux in TMT-treated astrocytes was consistent with a block of the late stages of autophagy and was accompanied by a progressive accumulation of the microtubule associated protein light chain 3 (LC3) and of p62/SQSTM1. Interestingly, an increased immunoreactivity for p62/SQSTM1 was also observed in hippocampal astrocytes detected in brain slices of TMT-intoxicated rats. The time-lapse recordings of AVs in EGFP-mCherry-LC3B transfected astrocytes demonstrated a reduced mobility of autophagosomes after TMT exposure respect to control cells. The observed block of the autophagic flux cannot be overcome by known autophagy inducers such as rapamycin or 0.5mM lithium. Although ineffective when used at 0.5mM, lithium at higher concentrations (2mM) was able to protect astrocyte cultures from TMT toxicity. This effect correlated well with its ability to determine the phosphorylation/inactivation of glycogen kinase synthase-3β (GSK-3β)

Idiopathic sensorineural hearing loss in the only hearing ear

A retrospective chart review was used for 31 patients with sudden, progressive or fluctuating sensorineural hearing loss (SHL) in the only hearing ear who had been consecutively evaluated at the ENT, Audiology and Phoniatrics Unit of the University of Pisa. The group of patients was evaluated with a complete history review, clinical evaluation, imaging exam (MRI, CT), audiologic tests (tone and speech audiometry, tympanometry, study of stapedial reflexes, ABR and otoacoustic emission) evaluation. In order to exclude genetic causes, patients were screened for CX 26 and CX30 mutations and for mitochondrial DNA mutation A1555G. Patients with sudden or rapidly progressive SHL in the only hearing ear were treated with osmotic diuretics and corticosteroids. In patients who did not respond to intravenous therapy we performed intratympanic injections of corticosteroid. Hearing aids were fitted when indicated and patients who developed severe to profound SHL were scheduled for cochlear implant surgery. The aim of this study is to report and discuss the epidemiology, aetiopathogenesis, therapy and clinical characteristic of patients affected by SHL in the only hearing hear and to discuss the issues related to the cochlear implant procedure in some of these patients, with regard to indications, choice of the ear to implant and results

Measles among healthcare workers in Italy. Is it time to act?

Vaccination of healthcare workers (HCWs) against measles is strongly recommended in Europe. In this study, we examined the impact of measles on Italian HCWs by systematically and quantitatively analyzing measles cases involving HCWs over time and by identifying the epidemiological characteristics of the respective measles outbreaks. We retrieved data on measles cases from the Italian national integrated measles and rubella surveillance system from January 2013 to May 2019. Additionally, we performed a systematic review of the literature and an analysis of the measles and rubella aggregate outbreaks reporting forms from 2014 to 2018. Our review suggests that preventing measles infection among HCWs in disease outbreaks may be crucial for the elimination of measles in Italy. National policies aiming to increase HCW immunization rates are fundamental to the protection of HCWs and patients, will limit the economic impact of outbreaks on the institutions affected and will help achieve the elimination goal