Effects of Forward Error Correction on Communications Aware Evasion Attacks

Recent work has shown the impact of adversarial machine learning on deep neural networks (DNNs) developed for Radio Frequency Machine Learning (RFML) applications. While these attacks have been shown to be successful in disrupting the performance of an eavesdropper, they fail to fully support the primary goal of successful intended communication. To remedy this, a communications-aware attack framework was recently developed that allows for a more effective balance between the opposing goals of evasion and intended communication through the novel use of a DNN to intelligently create the adversarial communication signal. Given the near ubiquitous usage of forward error correction (FEC) coding in the majority of deployed systems to correct errors that arise, incorporating FEC in this framework is a natural extension of this prior work and will allow for improved performance in more adverse environments. This work therefore provides contributions to the framework through improved loss functions and design considerations to incorporate inherent knowledge of the usage of FEC codes within the transmitted signal. Performance analysis shows that FEC coding improves the communications aware adversarial attack even if no explicit knowledge of the coding scheme is assumed and allows for improved performance over the prior art in balancing the opposing goals of evasion and intended communications

The clustering and bias of radio-selected AGN and star-forming galaxies in the COSMOS field

Dark matter haloes in which galaxies reside are likely to have a significant impact on their evolution. We investigate the link between dark matter haloes and their constituent galaxies by measuring the angular two-point correlation function of radio sources, using recently released 3 GHz imaging over $\sim 2 \ \mathrm{deg}^2$of the COSMOS field. We split the radio source population into Star Forming Galaxies (SFGs) and Active Galactic Nuclei (AGN), and further separate the AGN into radiatively efficient and inefficient accreters. Restricting our analysis to$z<1$, we find SFGs have a bias,$b = 1.5 ^{+0.1}_{-0.2}$, at a median redshift of$z=0.62$. On the other hand, AGN are significantly more strongly clustered with$b = 2.1\pm 0.2$at a median redshift of 0.7. This supports the idea that AGN are hosted by more massive haloes than SFGs. We also find low-accretion rate AGN are more clustered ($b = 2.9 \pm 0.3$) than high-accretion rate AGN ($b = 1.8^{+0.4}_{-0.5}$) at the same redshift ($z \sim 0.7$), suggesting that low-accretion rate AGN reside in higher mass haloes. This supports previous evidence that the relatively hot gas that inhabits the most massive haloes is unable to be easily accreted by the central AGN, causing them to be inefficient. We also find evidence that low-accretion rate AGN appear to reside in halo masses of$M_{h} \sim 3-4 \times 10^{13}h^{-1}$M$_{\odot}$at all redshifts. On the other hand, the efficient accreters reside in haloes of$M_{h} \sim 1-2 \times 10^{13}h^{-1}$M$_{\odot}$at low redshift but can reside in relatively lower mass haloes at higher redshifts. This could be due to the increased prevalence of cold gas in lower mass haloes at$z \ge 1$compared to$z<1$.Comment: 20 pages, 10 figures, 1 table, accepted by MNRA

Neural Bases of Cognitive Impairments in Post-Traumatic Stress Disorders : A Mini-Review of Functional Magnetic Resonance Imaging Findings

Introduction: Post-Traumatic Stress Disorder (PTSD) is often associated with impairments in emotional and cognitive domains. Contrarily to the emotional sphere, neural basis underpinnings to cognitive impairments are still not well known. Methods: We performed a bibliographic search on PUBMED of all the studies investigating the cognitive impairments in PTSD individuals. We considered only studies that applied cognitive tasks using a functional Magnetic Resonance Imaging technique. The inclusion criteria were met by nine studies. Results: Overall, PTSD individuals reported significant impairments in the dorsolateral prefrontal cortex, anterior cingulate cortex, inferior frontal gyrus, insula, inferior temporal cortex, supplement motor area, and Default Mode Network (DMN). Moreover, abnormal activity was reported in subcortical structures (e.g. hippocampus, amygdala, thalamus) and in the cerebellum. Limitations: Cognitive functioning was assessed using different cognitive tasks. Potential confounding factors such as age, sex, symptoms intensity, and comorbidities might have influenced the results. Conclusion: So far, the evidence reported that PTSD is characterized by cognitive impairments in several domains, such as attention, memory and autonomic arousal, which may be due to selective dysfunctions in brain regions that are part of cortical networks, the limbic system and DMN. However, further studies are needed in order to better assess the role of cognitive impairments in PTSD and to develop more targeted therapeutic approaches

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

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

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 $rms\sim2.3$ $\mu$Jy/beam, cataloging 10,899 source components above $5\times rms$. 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 $z\sim5$. 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 $\sim$10 $\mu$Jy. We find that at 3 GHz flux densities above $\sim$400 $\mu$Jy quiescent, red galaxies, consistent with the low-excitation radio AGN class constitute the dominant fraction. Below densities of $\sim$200 $\mu$Jy 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

An Eddington ratio-driven origin for the LX- M∗relation in quiescent and star-forming active galaxies

A mild correlation exists in active galaxies between the mean black hole accretion, as traced by the mean X-ray luminosity and the host galaxy stellar mass M∗, characterised by a normalization steadily decreasing with cosmic time and lower in more quiescent galaxies. We create comprehensive semi-empirical mock catalogues of active black holes to pin down which parameters control the shape and evolution of the - M∗ relation of X-ray-detected active galaxies. We find that the normalization of the - M∗ relation is largely independent of the fraction of active galaxies (the duty cycle), but strongly dependent on the mean Eddington ratio, when adopting a constant underlying MBH - M∗ relation as suggested by observational studies. The data point to a decreasing mean Eddington ratio with cosmic time and with galaxy stellar mass at fixed redshift. Our data can be reproduced by black holes and galaxies evolving on similar MBH - M∗ relations but progressively decreasing their average Eddington ratios, mean X-ray luminosities, and specific star formation rates, when moving from the starburst to the quiescent phase. Models consistent with the observed - M∗ relation and independent measurements of the mean Eddington ratios are characterised by MBH - M∗ relations lower than those derived from dynamically measured local black holes. Our results point to the - M∗ relation as a powerful diagnostic to: (1) probe black hole-galaxy scaling relations and the level of accretion on to black holes; (2) efficiently break the degeneracies between duty cycles and accretion rates in cosmological models of black holes

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

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