Uncertain identification

Uncertainty about the choice of identifying assumptions is common in causal studies, but is often ignored in empirical practice. This paper considers uncertainty over models that impose different identifying assumptions, which can lead to a mix of point- and set- identified models. We propose performing inference in the presence of such uncertainty by generalizing Bayesian model averaging. The method considers multiple posteriors for the set-identified models and combines them with a single posterior for models that are either point-identified or that impose non-dogmatic assumptions. The output is a set of posteriors (post-averaging ambiguous belief ), which can be summarized by reporting the set of posterior means and the associated credible region. We clarify when the prior model probabilities are updated and characterize the asymptotic behavior of the posterior model probabilities. The method provides a formal framework for conducting sensitivity analysis of empirical findings to the choice of identifying assumptions. For example, we find that in a standard monetary model one would need to attach a prior probability greater than 0.28 to the validity of the assumption that prices do not react contemporaneously to a monetary policy shock, in order to obtain a negative response of output to the shock

Uncertain identification

Uncertainty about the choice of identifying assumptions is common in causal studies, but is often ignored in empirical practice. This paper considers uncertainty over models that impose different identifying assumptions, which, in general, leads to a mix of point- and set-identified models. We propose performing inference in the presence of such uncertainty by generalizing Bayesian model averaging. The method considers multiple posteriors for the set-identified models and combines them with a single posterior for models that are either point-identified or that impose non-dogmatic assumptions. The output is a set of posteriors (post-averaging ambiguous belief) that are mixtures of the single posterior and any element of the class of multiple posteriors, with weights equal to the posterior model probabilities. We suggest reporting the range of posterior means and the associated credible region in practice, and provide a simple algorithm to compute them. We establish that the prior model probabilities are updated when the models are "distinguishable" and/or they specify different priors for reduced-form parameters, and characterize the asymptotic behavior of the posterior model probabilities. The method provides a formal framework for conducting sensitivity analysis of empirical findings to the choice of identifying assumptions. In a standard monetary model, for example, we show that, in order to support a negative response of output to a contractionary monetary policy shock, one would need to attach a prior probability greater than 0.32 to the validity of the assumption that prices do not react contemporaneously to such a shock. The method is general and allows for dogmatic and non-dogmatic identifying assumptions, multiple point-identified models, multiple set-identified models, and nested or non-nested models

Identification and characterisation of tomato torrado virus, a new plant picorna-like virus from tomato

A new virus was isolated from tomato plants from the Murcia region in Spain which showed symptoms of ‘torrado disease’ very distinct necrotic, almost burn-like symptoms on leaves of infected plants. The virus particles are isometric with a diameter of approximately 28 nm. The viral genome consists of two (+)ssRNA molecules of 7793 (RNA1) and 5389 nts (RNA2). RNA1 contains one open reading frame (ORF) encoding a predicted polyprotein of 241 kDa that shows conserved regions with motifs typical for a protease-cofactor, a helicase, a protease and an RNA-dependent RNA polymerase. RNA2 contains two, partially overlapping ORFs potentially encoding proteins of 20 and 134 kDa. These viral RNAs are encapsidated by three proteins with estimated sizes of 35, 26 and 23 kDa. Direct protein sequencing mapped these coat proteins to ORF2 on RNA2. Phylogenetic analyses of nucleotide and derived amino acid sequences showed that the virus is related to but distinct from viruses belonging to the genera Sequivirus, Sadwavirus and Cheravirus. This new virus, for which the name tomato torrado virus is proposed, most likely represents a member of a new plant virus genus

Transcriptomic analysis of nickel exposure in Sphingobium sp. ba1 cells using RNA-seq

Nickel acts as cofactor for a number of enzymes of many bacteria species. Its homeostasis is ensured by proteins working as ion efflux or accumulation systems. These mechanisms are also generally adopted to counteract life-threatening high extra-cellular Ni2+concentrations. Little is known regarding nickel tolerance in the genus Sphingobium. We studied the response of the novel Sphingobium sp. ba1 strain, able to adapt to high Ni2+concentrations. Differential gene expression in cells cultured in 10 mM Ni2+, investigated by RNA-seq analysis, identified 118 differentially expressed genes. Among the 90 up-regulated genes, a cluster including genes coding for nickel and other metal ion efflux systems (similar to either cnrCBA, nccCBA or cznABC) and for a NreB-like permease was found. Comparative analyses among thirty genomes of Sphingobium species show that this cluster is conserved only in two cases, while in the other genomes it is partially present or even absent. The differential expression of genes encoding proteins which could also work as Ni2+-accumulators (HupE/UreJ-like protein, NreA and components of TonB-associated transport and copper-homeostasis systems) was also detected. The identification of Sphingobium sp. ba1 strain adaptive mechanisms to nickel ions, can foster its possible use for biodegradation of poly-aromatic compounds in metal-rich environments

In Vitro Antibacterial Activity of Cysteine Protease Inhibitor from Kiwifruit (Actinidia deliciosa)

The need for replacing traditional pesticides with alternative agents for the management of agricultural pathogens is rising worldwide. In this study, a cysteine proteinase inhibitor (CPI), 11 kDa in size, was purified from green kiwifruit to homogeneity. We examined the growth inhibition of three plant pathogenic Gram-negative bacterial strains by kiwi CPI and attempted to elucidate the potential mechanism of the growth inhibition. CPI influenced the growth of phytopathogenic bacteria Agrobacterium tumefaciens (76.2 % growth inhibition using 15 mu M CPI), Burkholderia cepacia (75.6 % growth inhibition) and, to a lesser extent, Erwinia carotovora (44.4 % growth inhibition) by inhibiting proteinases that are excreted by these bacteria. Identification and characterization of natural plant defense molecules is the first step toward creation of improved methods for pest control based on naturally occurring molecules

Gli scavi dell’Università degli Studi di Napoli “L’Orientale” nell’abitato greco-romano di Cuma (2007-2013)

Sintesi degli scavi nell'abitato greco-romano di Cuma, anni 2007-201

Macroprudential supervision in insurance: setting the scene

Macroprudential policies, tools and supervision have become the most important regulatory and supervisory innovation across the globe in recent years. This very relevant topic, which became important after the last financial crisis, is the subject matter of numerous studies and policy papers. Most contributions to the field however are banking-oriented and rarely address other segments of the financial sector. It seems only natural therefore that a more balanced approach is required

Contributo glossario: mediazione interculturale, mediazione linguistica, intercultura/interculturalità, transcultura, multicultura, multilingue

Documento pubblicato sul sito www.dif.tno.it/cnosso , nell'ambito del progetto di ricerca e formazione CNOSSO (Sistemi basati sulla conoscenza per l'apprendimento in rete e la fruizione personalizzata dei beni culturali, Unione Europea FERS, MIUR, Università di Bari, Politecnico di Bari, Università di Foggia, Università di Lecce, Editori Laterza, Nuova Comunicazione, Sfera Spa, Tecnopolis Csata- SCRL), Obiettivo realizzativo 5 (Modelli per la Mediazione linguistica e interculturale)