Integrin β1 regulates marginal zone B cell differentiation and PI3K signaling

Marginal zone (MZ) B cells represent innate-like B cells that mediate a fast immune response. The adhesion of MZ B cells to the marginal sinus of the spleen is governed by integrins. Here, we address the question of whether β1-integrin has additional functions by analyzing Itgb1fl/flCD21Cre mice in which the β1-integrin gene is deleted in mature B cells. We find that integrin β1–deficient mice have a defect in the differentiation of MZ B cells and plasma cells. We show that integrin β1–deficient transitional B cells, representing the precursors of MZ B cells, have enhanced B cell receptor (BCR) signaling, altered PI3K and Ras/ERK pathways, and an enhanced interaction of integrin-linked kinase (ILK) with the adaptor protein Grb2. Moreover, the MZ B cell defect of integrin β1–deficient mice could, at least in part, be restored by a pharmacological inhibition of the PI3K pathway. Thus, β1-integrin has an unexpected function in the differentiation and function of MZ B cells

Josephson surface plasmons in spatially confined cuprate superconductors

In this work, we generalize the theory of localized surface plasmons to the case of high-Tc cuprate superconductors, spatially confined in the form of small spherical particles. At variance from ordinary metals, cuprate superconductors are characterized by a low-energy bulk excitation known as the Josephson plasma wave (JPW), arising from interlayer tunneling of the condensate along the c-axis. The effect of the JPW is revealed in a characteristic spectrum of surface excitations, which we call Josephson surface plasmons. Our results, which apply to any material with a strongly anisotropic electromagnetic response, are worked out in detail for the case of multilayered superconductors supporting both low-frequency (acoustic) and transverse-optical JPW. Spatial confinement of the Josephson plasma waves may represent a new degree of freedom to engineer their frequencies and to explore the link between interlayer tunnelling and high-Tc superconductivity

Star formation properties of sub-mJy radio sources

We investigate the star formation properties of ~800 sources detected in one of the deepest radio surveys at 1.4 GHz. Our sample spans a wide redshift range (~0.1 - 4) and about four orders of magnitude in star formation rate (SFR). It includes both star forming galaxies (SFGs) and active galactic nuclei (AGNs), further divided into radio-quiet and radio-loud objects. We compare the SFR derived from the far infrared luminosity, as traced by Herschel, with the SFR computed from their radio emission. We find that the radio power is a good SFR tracer not only for pure SFGs but also in the host galaxies of RQ AGNs, with no significant deviation with redshift or specific SFR. Moreover, we quantify the contribution of the starburst activity in the SFGs population and the occurrence of AGNs in sources with different level of star formation. Finally we discuss the possibility of using deep radio survey as a tool to study the cosmic star formation history.Comment: 18 pages, 14 figures, 1 table (available in its entirety as ancillary data

Elastic Light Scattering by Semiconductor Quantum Dots

Elastic light scattering by low-dimensional semiconductor objects is investigated theoretically. The differential cross section of resonant light scattering on excitons in quantum dots is calculated. The polarization and angular distribution of scattered light do not depend on the quantum-dot form, sizes and potential configuration if light wave lengths exceed considerably the quantum-dot size. In this case the magnitude of the total light scattering cross section does not depend on quantum-dot sizes. The resonant total light scattering cross section is about a square of light wave length if the exciton radiative broadening exceeds the nonradiative broadening. Radiative broadenings are calculated

English job titles in italian : the Case of Manager and Engineer

In a globalized job market, the use of English job titles to advertise vacancies and positions in non-English-speaking countries is becoming increasingly frequent. This trend seems to be primarily motivated by the desire to give jobs an international appeal. While some job titles fill lexical gaps and are successfully integrated, others enter in competition with national equivalents, generating \u2018multiple terminology\u2019 in the receiving languages. The aim of this paper is to identify the stylistic and pragmatic reasons which determine the success of an Anglicism in the receiving language, despite the existence of a domestic equivalent. To this end, we have conducted a linguistic analysis of two terms used in the Italian job market \u2013 manager and engineer \u2013 which have entered the Italian language in the same historical period (end of the 19th century). However, manager has developed into a very successful general purpose term in Italian, generating a wide range of compounds, vice versa engineer has given rise to several compounds but has not been integrated as a standalone lexical item. Our data indicates that the reasons for the success of manager are linked to its equivalents not being domain-specific, whereas for engineer the existence of the Italian cognate ingegnere, formally similar but semantically different, prevents the assimilation of this Anglicism. The data discussed are drawn from general and specialized dictionaries, official descriptions of occupations in Italian and in English, and from web corpora queried through the Sketch Engine system

Job-hunting in Italy : Building a glossary of “English-inspired” job titles

This paper reports on a study of \u201cEnglish-inspired\u201d job titles retrieved from a specialized corpus of job advertisements posted on Italian web pages. This corpus was created using the WebBootCat tool in the Sketch Engine, following the methodology described by Baroni and Bernardini (2004) and Baroni et al. (2006). The aim is to build a glossary of English job titles to be published online as a tool for prospective job applicants. Checking their status in English and Italian dictionaries, we will establish whether the titles collected are current English terms, false Anglicisms, or \u201cEnglish-inspired\u201d creations. The preliminary findings consist of a list of 30 job titles which are analyzed in terms of form and meaning, and grouped into categories depending on whether an Italian equivalent is available or not. The corpus of job postings is used to analyze the lexical profile of job titles, their meaning and/or possible covert manipulative intent. In fact, data shows that some English job titles may be preferred to Italian equivalents to attribute greater status to the actual job designation and description. Moreover, some job titles are characterized by complex pre-modification which may confuse the ultimate users, i.e. job hunters themselves

Analogue of the Kubo Formula for Conductivity of Spatially Inhomogeneous Systems and Electric Fields

The average of densities of currents and charges, induced by a weak electromagnetic field in spatially inhomogeneous are calculated at final temperatures. The Kubo formula for a conductivity tensor is generalized for spatially inhomogeneous systems and fields. The contributions containing electric fields and derivative from fields on coordinates are allocated. The Semiconductor quantum wells, wires and dots may be considered as spatially inhomogeneous systems.Comment: 10 page

Effect of the Spatial Dispersion on the Shape of a Light Pulse in a Quantum Well

Reflectance, transmittance and absorbance of a symmetric light pulse, the carrying frequency of which is close to the frequency of interband transitions in a quantum well, are calculated. Energy levels of the quantum well are assumed discrete, and two closely located excited levels are taken into account. A wide quantum well (the width of which is comparable to the length of the light wave, corresponding to the pulse carrying frequency) is considered, and the dependance of the interband matrix element of the momentum operator on the light wave vector is taken into account. Refractive indices of barriers and quantum well are assumed equal each other. The problem is solved for an arbitrary ratio of radiative and nonradiative lifetimes of electronic excitations. It is shown that the spatial dispersion essentially affects the shapes of reflected and transmitted pulses. The largest changes occur when the radiative broadening is close to the difference of frequencies of interband transitions taken into account.Comment: 7 pages, 5 figure