Modelling the spread of Covid19 in Italy using a revised version of the SIR model

In this paper, we present a model to predict the spread of the Covid-19 epidemic and apply it to the specific case of Italy. We started from a simple Susceptible, Infected, Recovered (SIR) model and we added the condition that, after a certain time, the basic reproduction number $R_0$ exponentially decays in time, as empirically suggested by world data. Using this model, we were able to reproduce the real behavior of the epidemic with an average error of 5\%. Moreover, we illustrate possible future scenarios, associated to different intervals of $R_0$. This model has been used since the beginning of March 2020, predicting the Italian peak of the epidemic in April 2020 with about 100.000 detected active cases. The real peak of the epidemic happened on the 20th of April 2020, with 108.000 active cases. This result shows that the model had predictive power for the italian case.Comment: The model presented in this paper has been adopted on Covstat.it. Errata corrige in the abstrac

Genomic and cytogenetic localization of the carotenoid genes in the aphid genome

Data published in the scientific literature suggests a possible link between chromosomal rearrangements involving autosomes 1 and 3 and the presence of red morphs in the peach-potato aphid Myzus persicae (Sulzer). In order to begin a study of this relationship, we analysed the genomic and chromosomal location of genes involved in carotenoid biosynthesis in M. persicae and the pea aphid, Acyrthosiphon pisum (Harris), since carotenoids are the basis of the colour in many aphid species. Genomic analysis identified a DNA sequence containing carotenoid genes in synteny between the 2 species. According to the results obtained using in situ PCR, carotenoid genes were located in a subterminal portion of autosome 1 in both species. The same localization has also been observed in the onion aphid Neotoxoptera formosana Takahashi that, as M. persicae and A. pisum, belongs to the tribe Macrosiphini, thereby suggesting a synteny of this chromosomal region in aphids. In situ PCR experiments performed on 2 M. persicae asexual lineages bearing heterozygous translocations involving autosomes 1 and 3 revealed that carotenoid genes were located within chromosomal portions involved in recurrent rearrangements. We also verified by bioinformatics analyses the presence of fragile sites that could explain these recurrent rearrangements in M. persicae

The evolutionary history and functional divergence of trehalase (treh) genes in insects

Trehalases (treh) have been found in different organisms, such as bacteria, fungi, yeast, nematodes, insects, vertebrates and plants. Their biochemical properties are extremely variable and not yet fully understood. Gene expression patterns have shown differences among insect species suggesting a potential functional diversification of trehalase enzymes during their evolution. A second gene family encoding for enzymes with hypothetical trehalase activity has bene been repeatedly annotated in insect genome as acid trehalases/acid trehalase-like (ath), but its functional role is still not clear. The currently available large amount of genomic data from many insect species may enable deeper studies allowing a better understanding of the evolutionary history, the phylogenetic relationships and possible roles of trehalase encoding genes in this taxon. The aim of the present study is to infer the evolutionary history of trehalases and acid trehalase genes in insects and analyse the trehalase functional divergence during their evolution, combining nucleotides sequences phylogenyphylogenetic, protein conservation and genomic synteny/colinearity analyses

Elachistocleis haroi Pereyra, Akmentins, Laufer & Vaira, 2013 (Anura: Microhylidae) en Paraguay

Elachistocleis haroi (Anura: Microhylidae) fue descrita de las Provincias de Jujuy, Salta y Formosa en Argentina y el departamento Tarija en Bolivia. Sobre la base de ejemplares albergados en el Museo Nacional de Historia Natural del Paraguay y Colección Zoológica de la Facultad de Ciencias Exactas y Naturales, extendemos la distribución conocida de la especie a los departamentos de Alto Paraguay, Boquerón y Presidente Hayes, en la Región Occidental de Paraguay.Elachistocleis haroi (Anura: Microhylidae) was described from the provinces of Jujuy, Salta and Formosa in Argentina and the Tarija department in Bolivia. Based on specimens housed in the Museo Nacional de Historia Natural del Paraguay and Colección Zoológica de la Facultad de Ciencias Exactas y Naturales, we extend the range of the species to the departments of Alto Paraguay, Boquerón and Presidente Hayes, in western Paraguay.Fil: Caballero Gini, Andrea. Universidad Nacional de Asuncion; ParaguayFil: Bueno Villafañe, Diego. Universidad Nacional de Asuncion; Paraguay. Museo Nacional de Historia Natural del Paraguay; ParaguayFil: Romero Nardelli, L.. Universidad Nacional de Asuncion; ParaguayFil: Lavilla, Esteban Orlando. Fundación Miguel Lillo. Dirección de Zoología. Instituto de Herpetología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tucumán; Argentin

First-principle theory of correlated transport through nano-junctions

We report the inclusion of electron-electron correlation in the calculation of transport properties within an ab initio scheme. A key step is the reformulation of Landauer's approach in terms of an effective transmittance for the interacting electron system. We apply this framework to analyze the effect of shortrange interactions on Pt atomic wires and discuss the coherent and incoherent correction to the mean-field approach