622 research outputs found

    Atomic interactions for qubit-error compensation

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    Experimental imperfections induce phase and population errors in quantum systems. We present a method to compensate unitary errors affecting also the population of the qubit states. This is achieved through the interaction of the target qubit with an additional control qubit. We show that our approach works well for single-photon and two-photon excitation schemes. In the first case, we study two reduced models: (i) a two-level system in which the interaction corresponds to an effective level shift and (ii) a three-level one describing two qubits in the Bell triplet subspace. In the second case, a double Stimulated Raman Adiabatic Passage process is presented with comparable compensation efficiency with respect to the single-photon case

    B cells in the formation of Tertiary Lymphoid Organs in autoimmunity, transplantation and tumorigenesis.

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    TLS develop in target organs of autoimmune diseases, transplantation and cancer. ‱ TLS can function as germinal centres supporting B-cell selection/differentiation. ‱ TLS can be destructive or have beneficial effects at the site of inflammation/disease. ‱ Therapeutic targeting of TLS results in beneficial effects in patients, though inhibition may lead to immune suppression while stimulation may lead to autoimmunity. Tertiary lymphoid organs named also tertiary lymphoid structures (TLS) often occur at sites of autoimmune inflammation, organ transplantation and cancer. Although the mechanisms for their formation/function are not entirely understood, it is known that TLS can display features of active germinal centres supporting the proliferation and differentiation of (auto)-reactive B cells. In this Review, we discuss current knowledge on TLS-associated B cells with particular reference on how within diseased tissues these structures are linked to either deleterious or protective outcomes in patients and the potential for therapeutic targeting of TLS through novel drugs

    The role of co-parenting alliance as a mediator between trait anxiety, family system maladjustment, and parenting stress in a sample of non-clinical Italian parents

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    This study investigated the role of co-parenting alliance in mediating the influence of parents' trait anxiety on family system maladjustment and parenting stress. A sample of 1606 Italian parents (803 mothers and 803 fathers) of children aged one to 13 years completed measures of trait anxiety (State Trait Anxiety Inventory-Y), co-parenting alliance (Parenting Alliance Measure), family system maladjustment (Family Assessment Measure-III), and parenting stress (Parenting Stress Inventory-Short Form). These variables were investigated together comparing two structural equations model-fitting including both partners. A model for both mothers and fathers was empirically devised as a series of associations between parent trait anxiety (independent variable), family system maladjustment and parenting stress (dependent variables), mediated by coparenting alliance, with the insertion of cross predictions between mothers and fathers and correlations between dependent variables for both parents. Results indicated that the relation between mothers and fathers' trait anxiety, family system maladjustment and parenting stress was mediated by the level of co-parenting alliance. Understanding the role of couples' co-parenting alliance could be useful during the family assessment and/or treatment, since it is an efficient and effective tool to improve the family system maladjustment and stress

    Star-forming galaxies versus low- and high-excitation radio AGN in the VLA-COSMOS 3GHz Large Project

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    We study the composition of the faint radio population selected from the VLA-COSMOS 3GHz Large Project, a radio continuum survey performed at 10 cm wavelength. The survey covers the full 2 square degree COSMOS field with mean rms∌2.3rms\sim2.3 ÎŒ\muJy/beam, cataloging 10,899 source components above 5×rms5\times rms. By combining these radio data with UltraVISTA, optical, near-infrared, and Spitzer/IRAC mid-infrared data, as well as X-ray data from the Chandra Legacy, and Chandra COSMOS surveys, we gain insight into the emission mechanisms within our radio sources out to redshifts of z∌5z\sim5. From these emission characteristics we classify our souces as star forming galaxies or AGN. Using their multi-wavelength properties we further separate the AGN into sub-samples dominated by radiatively efficient and inefficient AGN, often referred to as high- and low-excitation emission line AGN. We compare our method with other results based on fitting of the sources' spectral energy distributions using both galaxy and AGN spectral models, and those based on the infrared-radio correlation. We study the fractional contributions of these sub-populations down to radio flux levels of ∌\sim10 ÎŒ\muJy. We find that at 3 GHz flux densities above ∌\sim400 ÎŒ\muJy quiescent, red galaxies, consistent with the low-excitation radio AGN class constitute the dominant fraction. Below densities of ∌\sim200 ÎŒ\muJy star-forming galaxies begin to constitute the largest fraction, followed by the low-excitation, and X-ray- and IR-identified high-excitation radio AGN.Comment: 7 pages, 3 figures, The many facets of extragalactic radio surveys: towards new scientific challenges, Bologna 20-23 October 201

    Average radio spectral energy distribution of highly star-forming galaxies

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    The infrared-radio correlation (IRRC) offers a way to assess star formation from radio emission. Multiple studies found the IRRC to decrease with increasing redshift. This may in part be due to the lack of knowledge about the possible radio spectral energy distributions (SEDs) of star-forming galaxies. We constrain the radio SED of a complete sample of highly star-forming galaxies (SFR > 100 M?/ yr) based on the VLA-COSMOS 1.4 GHz Joint and 3 GHz Large Project catalogs. We reduce archival GMRT 325 MHz and 610 MHz observations, broadening the rest-frame frequency range to 0.3-15 GHz. Employing survival analysis and fitting a double power law SED, we find that the slope steepens from a spectral index of a1 = 0.51±0.04 below 4.5 GHz to a2 = 0.98±0.07 above 4.5 GHz. Our results suggest that the use of a K-correction assuming a single power-law radio SED for star forming galaxies is likely not the root cause of the IRRC trend

    The VLA-COSMOS 3 GHz Large Project: Average radio spectral energy distribution of highly star-forming galaxies

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    We construct the average radio spectral energy distribution (SED) of highly star-forming galaxies (HSFGs) up to z ~ 4. Infrared and radio luminosities are bound by a tight correlation that is defined by the so-called q parameter. This infrared-radio correlation provides the basis for the use of radio luminosity as a star-formation tracer. Recent stacking and survival analysis studies find q to be decreasing with increasing redshift. It was pointed out that a possible cause of the redshift trend could be the computation of rest-frame radio luminosity via a single power-law assumption of the star-forming galaxies' (SFGs) SED. To test this, we constrained the shape of the radio SED of a sample of HSFGs. To achieve a broad rest-frame frequency range, we combined previously published Very Large Array observations of the COSMOS field at 1:4 GHz and 3 GHz with unpublished Giant Meterwave Radio Telescope (GMRT) observations at 325MHz and 610MHz by employing survival analysis to account for non-detections in the GMRT maps. We selected a sample of HSFGs in a broad redshift range (z ? [0:3; 4]; SFR = 100 M yr-1) and constructed the average radio SED. By fitting a broken power-law, we find that the spectral index changes from a1 = 0:42-0:06 below a rest-frame frequency of 4:3 GHz to a2 = 0:94 ± 0:06 above 4:3 GHz. Our results are in line with previous low-redshift studies of HSFGs ( SFR > 10 M yr-1) that show the SED of HSFGs to differ from the SED found for normal SFGs ( SFR < 10 M yr-1). The difference is mainly in a steeper spectrum around 10 GHz, which could indicate a smaller fraction of thermal free-free emission. Finally, we also discuss the impact of applying this broken power-law SED in place of a simple power-law in K-corrections of HSFGs and a typical radio SED for normal SFGs drawn from the literature. We find that the shape of the radio SED is unlikely to be the root cause of the q-z trend in SFGs

    HST grism spectroscopy of z ∌3 massive quiescent galaxies: Approaching the metamorphosis

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    Tracing the emergence of the massive quiescent galaxy (QG) population requires the build-up of reliable quenched samples by distinguishing these systems from red, dusty star-forming sources. We present Hubble Space Telescope WFC3/G141 grism spectra of ten quiescent galaxy candidates selected at 2.5 < z < 3.5 in the COSMOS field. Spectroscopic confirmation for the whole sample is obtained within one to three orbits through the detection of strong spectral breaks and Balmer absorption lines. When their spectra are combined with optical to near-infrared photometry, star-forming solutions are formally rejected for the entire sample. Broad spectral indices are consistent with the presence of young A-type stars, which indicates that the last major episode of star formation has taken place no earlier than ∌300-800 Myr prior to observation. This confirms clues from their post-starburst UVJ colors. Marginalising over three different slopes of the dust attenuation curve, we obtain young mass-weighted ages and an average peak star formation rate (SFR) of ∌103 M yr-1 at zformation ∌ 3.5. Although mid- and far-IR data are too shallow to determine the obscured SFR on a galaxy-by-galaxy basis, the mean stacked emission from 3 GHz data constrains the level of residual-obscured SFR to be globally below 50 M yr-1, three times below the scatter of the coeval main sequence. Alternatively, the very same radio detection suggests a widespread radio-mode feedback by active galactic nuclei (AGN) four times stronger than in z ∌ 1.8 massive QGs. This is accompanied by a 30% fraction of X-ray luminous AGN with a black hole accretion rate per unit SFR enhanced by a factor of ∌30 with respect to similarly massive QGs at lower redshift. The average compact, high SĂ©rsic index morphologies of the galaxies in this sample, coupled with their young mass-weighted ages, suggest that the mechanisms responsible for the development of a spheroidal component might be concomitant with (or preceding) those causing their quenching

    The Parental Reflective Functioning Questionnaire in Mothers and Fathers of School-Aged Children

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    Research on parental reflective functioning (PRF)—defined as parents’ capacity to comprehend the developing mind of their child, reflect upon it, and hold in mind the inner life of the child—has mostly involved mothers of infants and young children, and rarely fathers and parents of school-aged children. The present study sought to extend research on PRF by examining aspects of the construct that are still scarcely explored, such as the role of gender and attachment; to investigate whether there were differences between mothers’ and fathers’ PRF and whether there were differences in PRF related to the gender and age of the child; and, finally, to assess the association between PRF and each parent’s attachment style. The Parental Reflective Functioning Questionnaire (PRFQ) and the Attachment Style Questionnaire (ASQ) were administered to a community sample of mothers and fathers of 385 children aged 3–10 years. A multi-group factor analysis supported the hypothesized three-factor model among both fathers and mothers. Univariate and multivariate analyses of variance showed that mothers had higher levels of interest and curiosity in their children’s mental states than fathers. Parents of daughters showed higher pre-mentalizing modes than parents of sons. Parents of preschool children showed less nonmentalizing modes than parents of children aged 8–10. Correlations between PRFQ and ASQ showed that both mothers’ and fathers’ interest in thinking about their child’s internal experience and in taking the child’s perspective were correlated with higher levels of secure attachment style. Research implications are discussed
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