Insights on cytotoxic cells of the colonial ascidian Botryllus schlosseri

Morula cells (MCs) represent the most abundant circulating hemocyte of the compound ascidian Botryllus schlosseri. They are cytotoxic cells involved in the rejection reaction between contacting, genetically incompatible colonies. Upon the recognition of foreign substances, they degranulate and release their content, which contribute to the cell death along the contact borders. A major role in MC-related cytotoxicity is exerted by the enzyme phenoloxidase (PO) that converts polyphenol substrata to quinones which, then, polymerize to form melanins. During this reaction, reactive oxygen species are formed which are the cause of MC-related cytotoxicity. Here, we carried out new analyses to investigate further the nature of MC content and its role in cytotoxicity. Results confirm that PO is located inside MC vacuoles together with arylsulfatase, iron and polyphenols/quinones, the latter probably representing ready-to-use cytotoxic molecules, deriving from the oxidation of DOPA-containing proteins. In addition, small DOPA-containing peptides, called tunichromes, are also present inside MCs. MC degranulation and PO-mediated cytotoxicity are prevented by secretion inhibitors and by H89 and calphostin C. The observation that PO activity is always detectable in MCs in the absence of protease treatment, and its inhibition by sulfites and sulfates, suggest a non-classical pathway of PO modulation in botryllid ascidians

On the radiality of constrained minimizers to the Schroedinger-Poisson-Slater energy

We study the radial symmetry of minimizers to the Schroedinger-Poisson-Slater (S-P-S) energy

The role of financing in international trade during good times and bad

The collapse of trade during the financial crisis can be tied, for the most part, to a drop in demand. Less talked about, however, is the role of financing—or lack thereof.International trade

Landscapes of data sets and functoriality of persistent homology

The aim of this article is to describe a new perspective on functoriality of persistent homology and explain its intrinsic symmetry that is often overlooked. A data set for us is a finite collection of functions, called measurements, with a finite domain. Such a data set might contain internal symmetries which are effectively captured by the action of a set of the domain endomorphisms. Different choices of the set of endomorphisms encode different symmetries of the data set. We describe various category structures on such enriched data sets and prove some of their properties such as decompositions and morphism formations. We also describe a data structure, based on coloured directed graphs, which is convenient to encode the mentioned enrichment. We show that persistent homology preserves only some aspects of these landscapes of enriched data sets however not all. In other words persistent homology is not a functor on the entire category of enriched data sets. Nevertheless we show that persistent homology is functorial locally. We use the concept of equivariant operators to capture some of the information missed by persistent homology

Transcriptome dynamics in the asexual cycle of the chordate Botryllus schlosseri

Background: We performed an analysis of the transcriptome during the blastogenesis of the chordate Botryllus schlosseri, focusing in particular on genes involved in cell death by apoptosis. The tunicate B. schlosseri is an ascidian forming colonies characterized by the coexistence of three blastogenetic generations: filter-feeding adults, buds on adults, and budlets on buds. Cyclically, adult tissues undergo apoptosis and are progressively resorbed and replaced by their buds originated by asexual reproduction. This is a feature of colonial tunicates, the only known chordates that can reproduce asexually. Results: Thanks to a newly developed web-based platform (http://botryllus.cribi.unipd.it), we compared the transcriptomes of the mid-cycle, the pre-take-over, and the take-over phases of the colonial blastogenetic cycle. The platform is equipped with programs for comparative analysis and allows to select the statistical stringency. We enriched the genome annotation with 11,337 new genes; 581 transcripts were resolved as complete open reading frames, translated in silico into amino acid sequences and then aligned onto the non-redundant sequence database. Significant differentially expressed genes were classified within the gene ontology categories. Among them, we recognized genes involved in apoptosis activation, de-activation, and regulation. Conclusions: With the current work, we contributed to the improvement of the first released B. schlosseri genome assembly and offer an overview of the transcriptome changes during the blastogenetic cycle, showing up- and down-regulated genes. These results are important for the comprehension of the events underlying colony growth and regression, cell proliferation, colony homeostasis, and competition among different generations

Gains and losses in intertemporal preferences: a behavioural study

According to recent evidence (Frederick, Loewenstein, & O’Donoghue, 2002), the traditional Discounted Utility model (Samuelson, 1937) has a limited ability to describe realistic models of behaviour and indeed there are several documented empirical regularities that seem to contradict this statement both in certainty and uncertainty conditions. This study focused on one of the best documented anomalies: sign effect or gain-loss asymmetry (Frederick et al., 2002; Loewenstein & Prelec, 1992; Read, 2004). Specifically, the study investigated the intertemporal preference for symmetric monetary rewards and punishments in certain conditions, and the no wealth effects hypothesis (Dimitri, 2007) by asking subjects to choose between two positive or two negative euro amounts available at different points in time. The experimental design applied here followed the same behavioural pattern of the neuroeconomics’ study on monetary rewards realized by McClure et al. (2004). The results confirmed a gain-loss asymmetry at least for medium and large euro amount and suggested new directions of research.intertemporal preferences; gains; losses; certainty; sign effect .

Semi-Parametric Empirical Best Prediction for small area estimation of unemployment indicators

The Italian National Institute for Statistics regularly provides estimates of unemployment indicators using data from the Labor Force Survey. However, direct estimates of unemployment incidence cannot be released for Local Labor Market Areas. These are unplanned domains defined as clusters of municipalities; many are out-of-sample areas and the majority is characterized by a small sample size, which render direct estimates inadequate. The Empirical Best Predictor represents an appropriate, model-based, alternative. However, for non-Gaussian responses, its computation and the computation of the analytic approximation to its Mean Squared Error require the solution of (possibly) multiple integrals that, generally, have not a closed form. To solve the issue, Monte Carlo methods and parametric bootstrap are common choices, even though the computational burden is a non trivial task. In this paper, we propose a Semi-Parametric Empirical Best Predictor for a (possibly) non-linear mixed effect model by leaving the distribution of the area-specific random effects unspecified and estimating it from the observed data. This approach is known to lead to a discrete mixing distribution which helps avoid unverifiable parametric assumptions and heavy integral approximations. We also derive a second-order, bias-corrected, analytic approximation to the corresponding Mean Squared Error. Finite sample properties of the proposed approach are tested via a large scale simulation study. Furthermore, the proposal is applied to unit-level data from the 2012 Italian Labor Force Survey to estimate unemployment incidence for 611 Local Labor Market Areas using auxiliary information from administrative registers and the 2011 Census

I lieviti del Vino Fiano di Avellino DOCG: la tipicità attraverso le biotecnologie

I microrganismi caratteristici di un prodotto tipico fermentato come il vino, dai quali dipendono molte delle proprietà organolettiche, riflettono, in molti casi, le caratteristiche dell’ambiente e dei sistemi di produzione. Infatti, i prodotti alimentari di nicchia legano la loro storia alla zona di produzione non solo per le tradizioni che si tramandano nel tempo, ma anche e soprattutto per la presenza di specie e ceppi di microrganismi che colonizzano la materia prima, nonché gli ambienti e le attrezzature di lavorazione, contribuendo in maniera decisiva a caratterizzare la tipicità del prodotto finale. Nello spirito delle “Denominazioni d’Origine”, particolare importanza deve essere ancora attribuita a tutti quegli elementi che creano il “legame” tra un determinato prodotto e una particolare zona geografica, la cultura della popolazione e tutti quegli aspetti che possono essere sintetizzati nell’insieme dei fattori storico-sociali nei quali risiedono i motivi dello sviluppo di un prodotto in una data area antropizzata. I microrganismi rientrano sicuramente tra questi fattori e costituiscono, anzi, uno dei “segreti” dei produttori artigianali che, nel tempo, sono stati svelati e convertiti in moderna tecnologia di trasformazione. Anche l’impiego di ceppi “autoctoni”, selezionati durante la trasformazione di prodotti tradizionali e legati allo sviluppo di componenti aromatiche desiderate, al prolungamento della shelf-life, agli aspetti salutistici dei prodotti finiti e cosìvia, può richiedere l’adattamento di protocolli produttivi già esistenti per migliorare le performance del(i) microrganismo(i). Tuttavia, tale innovazione non può essere “selvaggia”, bensì dovrebbe essere rispettosa degli aspetti essenziali e peculiari della tradizione di un prodotto. In questo lavoro svolto nell'areale del Fiano di Avellino DOCG si sono selezionati dall'ambiente vigneto 2 ceppi di Saccharomyces cerevisiae da utilizzare come starter nella produzione di qualità del vino Fian