514 research outputs found
Olinto de Pretto a Citizen Scientist a Century Ago
No full textThe paper is an examination by the author of the contents of a publication written by the Italian scholar Olinto De Pretto in 1904. This work was virtually unknown until it was cited a few years ago by the Italian professor Umberto Bartocci. Bartocci, who teaches the history of mathematics at the University of Peru, confirmed that De Pretto had written the mass-energy equivalence formula of special relativity in his paper a year before Einstein's famous article. Bartocci affirmed that Einstein could have understood formula by a friend of his who was a friend of De Pretto too Bartocci idea was not taken seriously. The author has now examined De Pretto's paper. In this paper De Pretto presented his vision of the universe as composed of matter and luminiferous ether in interaction with each other and both having an atomic structure. In this paper there are similarities with aspects of contemporary physics, including a formula formally equivalent to the most famous formula of Einstein's theory of relativity. However, De Pretto's vision is entirely internal to classical physics and is therefore surpassed by the facts. The figure of De Pretto, on the other hand, is very interesting and has strong similarities with the current phenomenon of citizen science. 
Corrigendum: In the Wake of the Ongoing Mass Mortality Events: Co-occurrence of Mycobacterium, Haplosporidium and Other Pathogens in Pinna nobilis Collected in Italy and Spain (Mediterranean Sea) (Frontiers in Marine Science, (2020), 7, 10.3389/fmars.2020.00048)
No full textIn the original article, the given name and surnames were switched for Elisabetta Antuonfermo, Simone Farina, Fulvio Salati, Daniela Mandas, Rossella Panarese, Eleonora Fiocchi, and Tobia Pretto. The correct version appears above. The authors apologize for this error and state that this does not change the scientific conclusions of the article in any way. The original article has been updated
HEALTH ASSESSMENT OF FLAT OYSTERS IN NORTHERN ADRIATIC SEA: ONE YEAR MONITORING
No full textHealth monitoring of Ostrea edulis in the Northern Adriatic Sea was conducted as a part of the INTERREG project MARINET, which aims to evaluate the feasibility of an Integrated Multi-Trophic Aquaculture (IMTA) model involving flat oysters and European sea bass. Juvenile flat oysters from Lim Bay (Croatia) were placed in lantern nets near sea bass farms in Duino (Italy). Health assessment were conducted for endemic diseases (Bonamia spp., Marteilia refringens) and other potential pathogens. 40 oysters were sampled every two months over a one-year period and analyzed following EURL protocols (IFREMER).
Histological analysis revealed a widespread presence of parasites referable to Perkinsus genus in oyster samples from Duino. The species was confirmed as Perkinsus mediterraneus by molecular analysis of the internal transcribed spacer (ITS) region of the ribosomal RNA gene complex. Schizonts and trophozoites of P. mediterraneus were observed in the connective tissues of the visceral mass, gonads, gills, labial palps, and mantle, often associated with significant haemocyte infiltration. Its prevalence, assessed by histology, varied during the monitoring period (2.5% - 85%) with a peak observed in October (17.5°C).
In addition to P. mediterraneus, Bonamia exitiosa was detected by real-time PCR from June to October but was not recorded from December to February, with temperatures below 15°C. A co-infection of B. exitiosa and P. mediterraneus was also identified in one specimen. Three oysters (p=1.25%) exhibited disseminated neoplasia. Neoplastic cells, characterized by reduced cytoplasm, enlarged nuclei, and the presence of mitotic figures, were observed in the connective tissues of various organs and in the haemolymph.
This is the first report of P. mediterraneus in Northern Adriatic, with temperature appearing to influence parasite prevalence. The detection of Perkinsus mediterraneus, Bonamia exitiosa and disseminated neoplasia in farmed Ostrea edulis highlights the importance of health monitoring
Betanodavirus ability to infect juvenile European sea bass, Dicentrarchus labrax, at different water salinity
No full textViral encephalopathy and retinopathy (VER) is one of the most devastating and economically relevant diseases for marine aquaculture. The presence of betanodavirus in freshwater fish is recorded, but very little is known about VER outbreaks in marine species reared in freshwater. Our study investigated the ability of betanodavirus to cause disease in European sea bass, Dicentrarchus labrax, reared at different salinity levels. Fish were challenged with RGNNV or mock infected by bath at different salinity levels (freshwater, 25â° and 33â°). Fish were checked twice a day and the dead ones were examined by standard virological techniques, by rRT-PCR and by histochemical and immunohistochemical analyses. All the infected groups showed a significant higher mortality rate than the one of the mock-infected group. VERv presence was confirmed by rRT-PCR. Histochemical and immunohistochemical analyses highlighted the typical lesions associated with VER. Our results highlight that salinity does not affect the ability of betanodavirus to induce clinical signs and mortality in European sea bass infected under experimental conditions. These results underline the great adaptation potential of VERv, which in combination with its already known high environmental resistance and broad host range, may explain the diffusion of this disease and the threat posed to aquaculture worldwide
Co-infection by a yeast-like organism in Thelohania-infected white-clawed crayfish Austropotamobius pallipes (complex) from Lombardy (Northern Italy).
No full textIn September 2011 an outbreak of the microsporidian parasite Thelohania contejeani (Henneguy, 1892) was reported in a population of Austropotamobius pallipes in Lombardy (Northern Italy). Macroscopically affected white-clawed crayfish collected from Agna creek, tributary of the river Chiese, in the province of Brescia, were analyzed using histological and bio-molecular techniques. Microscopicexamination of the abdominal and cardiac striated muscle fibers revealed microsporidia in several developmental stages with abundance of sporophorous vesicles and free mature spores. PCR and DNA sequencing reffered the parasite to species T. contejeani. Nearly half of the specimens affected by thelohaniasis also harboured a systemic infection by a yeast-like organism. Budding yeast-like cells were observed intracellularly in circulating haemocytes and free in the host haemolymph, particularly evident in the haemal sinuses of the hepatopancreas. These elliptical narrow base budding yeast cells (2,1-2,8 x 3,2-5,7 micron), stained positively with silver and periodic acid-Schiff (PAS) reactions. No hyphae or pseudohyphae were recorded. Yeast proliferation in the haemolymphatic system of crustaceans has been described from the order Isopoda, Amphipoda, Calanoida, Anostraca and Decapoda frequently associated with other pathogens. The co-infection of T. contejeani and yeast-like organisms in A. pallipes has been already described in England (Pixell Goodrich, 1965) and it has been speculated that yeasts could cause death by physically inhibiting haemolymph flow, as it was observed in Gammarus pulex. In the italian episode yeast infection was always associated with thelohaniasis (biased sample) and specimens appeared still viable despite heavy yeast proliferation. Further investigation are needed to identify the yeasts and to assess if they could act as primary pathogens or are mere opportunistic
On approximating the stationary distribution of time-reversible Markov chains
No full textApproximating the stationary probability of a state in a Markov chain through Markov chain Monte Carlo techniques is, in general, inefficient. Standard random walk approaches require O(t/p(v)) operations to approximate the probability p(v) of a state v in a chain with mixing time t, and even the best available techniques still have complexity O(t1.5/p(v)0.5); and since these complexities depend inversely on p(v), they can grow beyond any bound in the size of the chain or in its mixing time. In this paper we show that, for time-reversible Markov chains, there exists a simple randomized approximation algorithm that breaks this “small-p(v) barrier”
Microsporidian infection in white-claw crayfish populations is widespread in Northern Italy
No full textConservation measures for Austropotamobius pallipes may involve the relocation of animals into protected healthy sites or introduction into rearing center for species recovery. Prior to movement of animals it is therefore essential that health surveys are conducted to prevent further disease transfer. One of the most widespread significant disease of freshwater crayfish globally are microsporidiosis. The aim of this study was to trace a map of distribution of the affected white-clawed crayfish populations in Italy. The whiteness allows a macroscopically easy detection of the disease during crayfish sampling. During the period 2009-2016 we monitored 34 populations for a total of 3023 crayfish. From 11 streams we found and collected 100 crayfish suspected of microsporidiosis, and 86 out of them were analyzed using histological and biomolecular techniques. Nine populations were affected by Thelohania contejeani, eight by unidentified microsporidian, who was found in an Apennine crayfish population for the first tim
An Approach for the Construction of an Experimental Test Collection to Evaluate Search Systems that Exploit Annotation.
No full textUpdated distribution and characterization of crayfish plague and microsporidiosis affecting Austropotamobius pallipes complex in Trentino (Northeast Italy)
No full textOne of the causes of the decline in distribution and abundance of the endangered white-clawed crayfish Austropotamobius pallipes complex throughout Europe is the widespread invasion of alien crayfish and the associated spread of infectious diseases, primarily crayfish plague caused by Aphanomyces astaci. Although this disease usually causes mass mortality in A. pallipes, some wild populations appear tolerant towards A. astaci. Another relevant disease is microsporidiosis (porcelain disease), caused by the parasites Astathelohania contejeani and/or Nosema austropotamobii. In 2021-2024, we conducted a monitoring survey, aimed at mapping the distribution of A. astaci, A. contejeani and N. austropotamobii in wild populations of A. pallipes in Trentino (Northeast Italy). We applied non-invasive sampling methods to collect cuticular swabs from 31 of the 46 known populations, investigate the presence of A. astaci and if possible, identify its genotype through molecular analyses. Aphanomyces astaci was detected in 8 populations, and the presence of a low pathogenic genotype (genotype A) was confirmed in one of them. Thirty-three specimens from 10 populations showed macroscopic signs of porcelain disease, abdominal muscle tissues were collected and subjected to molecular evaluation. The presence of A. contejeani was identified in 23 individuals from 9 populations and N. austropotamobii was detected in 3 individuals, from 3 populations. 8 specimens collected from 6 populations were co-infected by the two microsporidians. This study was partly supported by the EU LIFE Programme: LIFE-CLAW, Crayfish Lineages Conservation in North-western Apennine (LIFE18 NAT/IT/000806), and by the SAGA and SAGA2 collaborative projects between FEM and IZSVe
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