Migration, labor tasks and production structure

We assess the effect of migrants’ stock on the production structure of the Italian provinces (NUTS3) in 1995–2006. Although the investigated time span is very short, the effect is small but statistically significant: a doubling in the ratio of foreign-born residents to the province population induces a significant increase in manufactures’ value added with respect to services’ value added between 12 and 21 per cent. These effects are more intense when considering an increase in foreign-born populations drawn from countries more different to Italy (in terms of GDP per capita and educational attainment). These results are compatible with the reduced form of a two-sector model where we assume that production is performed with one mobile factor and two sector-specific CES labor composites of simple and complex tasks. If migrants and natives have different productivity when performing simple or complex tasks, an inflow of migrants induces production restructuring in favor of the simple-task intensive sector

Accurate Estimation of a Coil Magnetic Dipole Moment

In this paper, a technique for accurate estimation of the moment of magnetic dipole is proposed. The achievable accuracy is investigated, as a function of measurement noise affecting estimation of magnetic field cartesian components. The proposed technique is validated both via simulations and experimentally.Comment: Preprin

Critical parameters and molecular analysis of lentiviral vector-mediated gene transfer into human haematopoietic stem cells

EThOS - Electronic Theses Online ServiceGBUnited Kingdo

An Evaluation Schema for the Ethical Use of Autonomous Robotic Systems in Security Applications

We propose a multi-step evaluation schema designed to help procurement agencies and others to examine the ethical dimensions of autonomous systems to be applied in the security sector, including autonomous weapons systems

Apoptotic signaling through CD95 (Fas/Apo-1) activates an acidic sphingomyelinase.

Intracellular pathways leading from membrane receptor engagement to apoptotic cell death are still poorly characterized. We investigated the intracellular signaling generated after cross-linking of CD95 (Fas/Apo-1 antigen), a broadly expressed cell surface receptor whose engagement results in triggering of cellular apoptotic programs. DX2, a new functional anti-CD95 monoclonal antibody was produced by immunizing mice with human CD95-transfected L cells. Crosslinking of CD95 with DX2 resulted in the activation of a sphingomyelinase (SMase) in promyelocytic U937 cells, as well as in other human tumor cell lines and in CD95-transfected murine cells, as demonstrated by induction of in vivo sphingomyelin (SM) hydrolysis and generation of ceramide. Direct in vitro measurement of enzymatic activity within CD95-stimulated U937 cell extracts, using labeled SM vesicles as substrates, showed strong SMase activity, which required pH 5.0 for optimal substrate hydrolysis. Finally, all CD95-sensitive cell lines tested could be induced to undergo apoptosis after exposure to cell-permeant C2-ceramide. These data indicate that CD95 cross-linking induces SM breakdown and ceramide production through an acidic SMase, thus providing the first information regarding early signal generation from CD95, and may be relevant in defining the biochemical nature of intracellular messengers leading to apoptotic cell death

APOBEC3G-Depleted Resting CD4+ T Cells Remain Refractory to HIV1 Infection

Background: CD4+ T lymphocytes are the primary targets of HIV1 but cannot be infected when fully quiescent, due to a post-entry block preventing the completion of reverse transcription. Chiu et al. recently proposed that this restriction reflects the action of APOBEC3G (A3G). They further suggested that T cell activation abrogates the A3G-mediated block by directing this protein to a high molecular mass complex. Methodology/Principal Findings: In the present work, we sought to explore further this model. However, we found that effective suppression of A3G by combined RNA interference and expression of HIV1 Vif does not relieve the restrictive phenotype of post-activation resting T cells. We also failed to find a correlation between HIV resistance and the presence of A3G in a low molecular complex in primary T cells. Conclusions/Significance: We conclude that A3G is unlikely to play a role in the HIV restrictive phenotype of quiescent T lymphocytes

Immigrant entrepreneurs, diasporas, and exports

This paper demonstrates the positive effect of immigrant entrepreneurs on manufacturing exports over and above that of diasporas. Using small\u2010scale regional administrative data, our instrumental variable estimates of export gravity models imply that ceteris paribus, that is, holding constant the total number of immigrants, the expected protrade effect of a migrant becoming an entrepreneur amounts to an average increase of US$5,946 in the export flows toward her country of origin. Besides these dyadic effects, immigrant entrepreneurs unlike nonentrepreneurial immigrants raise a region's overall competitiveness and export flows toward other destinations as well

Adaptive evolution of the symbiotic gene NORK is not correlated with shifts of rhizobial specificity in the genus Medicago

<p>Abstract</p> <p>Background</p> <p>The <it>NODULATION RECEPTOR KINASE </it>(<it>NORK</it>) gene encodes a Leucine-Rich Repeat (LRR)-containing receptor-like protein and controls the infection by symbiotic rhizobia and endomycorrhizal fungi in Legumes. The occurrence of numerous amino acid changes driven by directional selection has been reported in this gene, using a limited number of messenger RNA sequences, but the functional reason of these changes remains obscure. The <it>Medicago </it>genus, where changes in rhizobial associations have been previously examined, is a good model to test whether the evolution of <it>NORK </it>is influenced by rhizobial interactions.</p> <p>Results</p> <p>We sequenced a region of 3610 nucleotides (encoding a 392 amino acid-long region of the NORK protein) in 32 <it>Medicago </it>species. We confirm that positive selection in <it>NORK </it>has occurred within the <it>Medicago </it>genus and find that the amino acid positions targeted by selection occur in sites outside of solvent-exposed regions in LRRs, and other sites in the N-terminal region of the protein. We tested if branches of the <it>Medicago </it>phylogeny where changes of rhizobial symbionts occurred displayed accelerated rates of amino acid substitutions. Only one branch out of five tested, leading to <it>M. noeana</it>, displays such a pattern. Among other branches, the most likely for having undergone positive selection is not associated with documented shift of rhizobial specificity.</p> <p>Conclusion</p> <p>Adaptive changes in the sequence of the NORK receptor have involved the LRRs, but targeted different sites than in most previous studies of LRR proteins evolution. The fact that positive selection in <it>NORK </it>tends not to be associated to changes in rhizobial specificity indicates that this gene was probably not involved in evolving rhizobial preferences. Other explanations (<it>e.g</it>. coevolutionary arms race) must be tested to explain the adaptive evolution of <it>NORK</it>.</p