A mass threshold in the number density of passive galaxies at z∼\sim2

The process that quenched star formation in galaxies at intermediate and high redshift is still the subject of considerable debate. One way to investigate this puzzling issue is to study the number density of quiescent galaxies at z~2, and its dependence on mass. Here we present the results of a new study based on very deep Ks-band imaging (with the HAWK-I instrument on the VLT) of two HST CANDELS fields (the UKIDSS Ultra-deep survey (UDS) field and GOODS-South). The new HAWK-I data (taken as part of the HUGS VLT Large Program) reach detection limits of Ks>26 (AB mag). We select a sample of passively-evolving galaxies in the redshift range 1.4<z<2.5. Thanks to the depth and large area coverage of our imaging, we have been able to extend the selection of quiescent galaxies a magnitude fainter than previous analyses. Through extensive simulations we demonstrate, for the first time, that the observed turn-over in the number of quiescent galaxies at K>22 is real. This has enabled us to establish unambiguously that the number counts of quiescent galaxies at z~2 flatten and slightly decline at magnitudes fainter than Ks~22(AB mag.). We show that this trend corresponds to a stellar mass threshold $M_*10^{10.8}\,{\rm M_{\odot}}$ below which the mechanism that halts the star formation in high-redshift galaxies seems to be inefficient. Finally we compare the observed pBzK number counts with those of quiescent galaxies extracted from four different semi-analytic models. We find that none of the models provides a statistically acceptable description of the number density of quiescent galaxies at these redshifts. We conclude that the mass function of quiescent galaxies as a function of redshift continues to present a key and demanding challenge for proposed models of galaxy formation and evolution.Comment: Accepted for publication on Astronomy and Astrophysic

How do we know that our patients have benefitted from our ENT/Audiological interventions?: presented at the Annual Meeting of ADANO 2016 in Berlin

This short review article gives an introduction to some of the fundamental concepts and challenges facing measurement in hearing healthcare practice and research. The impact of hearing loss almost always extends beyond the sensory impairment itself, even when the measured degree of audiometric loss is mild. Yet, going beyond audibility, into the realm of measuring impact, takes us into a much more complex and less well-defined space. How does one therefore best measure the therapeutic benefit for evaluating efficacy or for clinical practice audit? Three case studies illustrate approaches to overcome such challenges. Each example highlights the importance of thinking critically about what it is one is seeking trying to measure, rather than selecting a questionnaire instrument based simply on its popularity or accessibility. We conclude by highlighting the important role that clinicians can play in collecting clinical data about their preferred instruments so that we have some evidence to inform decisions about good practice (content validity etc). We would also strongly support open data sharing as we believe that this is one of the best ways to make the most rapid progress the field

Perceptual and Memorial Contributions to Developmental Prosopagnosia

Developmental prosopagnosia (DP) is commonly associated with the failure to properly perceive individuating facial properties, notably those conveying configural or holistic content. While this may indicate that the primary impairment is perceptual, it is conceivable that some cases of DP are instead caused by a memory impairment, with any perceptual complaint merely allied rather than causal. To investigate this possibility, we administered a battery of face perception tasks to 11 individuals who reported that their face recognition difficulties disrupt daily activity and who also performed poorly on two formal tests of face recognition. Group statistics identified, relative to age- and gender-matched controls, difficulties in apprehending global-local relations and the holistic properties of faces, and in matching across viewpoints, but these were mild in nature and were not consistently evident at the level of individual participants. Six of the 11 individuals failed to show any evidence of perceptual impairment. In the remaining five individuals, no single perceptual deficit, or combination of deficits, was necessary or sufficient for poor recognition performance. These data suggest that some cases of DP are better explained by a memorial rather than perceptual deficit, and highlight the relevance of the apperceptive/associative distinction more commonly applied to the allied syndrome of acquired prosopagnosia

Second trimester inflammatory and metabolic markers in women delivering preterm with and without preeclampsia.

ObjectiveInflammatory and metabolic pathways are implicated in preterm birth and preeclampsia. However, studies rarely compare second trimester inflammatory and metabolic markers between women who deliver preterm with and without preeclampsia.Study designA sample of 129 women (43 with preeclampsia) with preterm delivery was obtained from an existing population-based birth cohort. Banked second trimester serum samples were assayed for 267 inflammatory and metabolic markers. Backwards-stepwise logistic regression models were used to calculate odds ratios.ResultsHigher 5-α-pregnan-3β,20α-diol disulfate, and lower 1-linoleoylglycerophosphoethanolamine and octadecanedioate, predicted increased odds of preeclampsia.ConclusionsAmong women with preterm births, those who developed preeclampsia differed with respect metabolic markers. These findings point to potential etiologic underpinnings for preeclampsia as a precursor to preterm birth

How do we know that our patients have benefitted from our ENT/Audiological interventions?: presented at the Annual Meeting of ADANO 2016 in Berlin

This short review article gives an introduction to some of the fundamental concepts and challenges facing measurement in hearing healthcare practice and research. The impact of hearing loss almost always extends beyond the sensory impairment itself, even when the measured degree of audiometric loss is mild. Yet, going beyond audibility, into the realm of measuring impact, takes us into a much more complex and less well-defined space. How does one therefore best measure the therapeutic benefit for evaluating efficacy or for clinical practice audit? Three case studies illustrate approaches to overcome such challenges. Each example highlights the importance of thinking critically about what it is one is seeking trying to measure, rather than selecting a questionnaire instrument based simply on its popularity or accessibility. We conclude by highlighting the important role that clinicians can play in collecting clinical data about their preferred instruments so that we have some evidence to inform decisions about good practice (content validity etc). We would also strongly support open data sharing as we believe that this is one of the best ways to make the most rapid progress the field

Realising the health and wellbeing of adolescents

Adolescence is a critical stage of life characterised by rapid biological, emotional, and social development. It is during this time that every person develops the capabilities required for a productive, healthy, and satisfying life. In order to make a healthy transition into adulthood, adolescents need to have access to health education, including education on sexuality1; quality health services, including sexual and reproductive; and a supportive environment both at home and in communities and countries.The global community increasingly recognises these vital needs of adolescents, and there is an emerging consensus that investing intensively in adolescents’ health and development is not only key to improving their survival and wellbeing but critical for the success of the post-2015 development agenda.2 The suggested inclusion of adolescent health in the United Nations secretary general’s Global Strategy for Women’s and Children’s Health is an expression of this growing awareness and represents an unprecedented opportunity to place adolescents on the political map beyond 2015. Ensuring that every adolescent has the knowledge, skills, and opportunities for a healthy, productive life and enjoyment of all human rights3 is essential for achieving improved health, social justice, gender equality, and other development goals.We argue that the priority in the revised Every Women Every Child Global Strategy needs to be giving adolescents a voice, expanding their choices and control over their bodies, and enabling them to develop the capabilities required for a productive, healthy, and satisfying life. We call for a global, participatory movement to improve the health of the world’s adolescents as part of a broader agenda to improve their wellbeing and uphold their rights

The Low-redshift Lyman Continuum Survey: Radio continuum properties of low-zz Lyman continuum emitters

The sources that leak Lyman-continuum (LyC) photons and lead to the reionisation of the universe are intensely studied using multiple observing facilities. Recently, the Low-redshift LyC Survey (LzLCS) has found the first large sample of LyC emitting galaxies at low redshift ($z\sim 0.3$) with the Hubble Space Telescope/Cosmic Origins Spectrograph. The LzLCS sample contains a robust estimate of the LyC escape fraction ($f_\mathrm{esc}^\mathrm{LyC}$) for 66 galaxies spanning a wide range of $f_\mathrm{esc}^\mathrm{LyC}$. Here we, for the first time, aim to study the radio continuum (RC) properties of LzLCS sources and their dependence on $f_\mathrm{esc}^\mathrm{LyC}$. We present Karl G. Jansky Very Large Array RC observations at C (4-8 GHz), S (2-4 GHz) and L (1-2 GHz) bands for a sub-sample of the LzLCS sources. The radio spectral index ($\alpha^{\mathrm{3GHz}}_\mathrm{6GHz}$) spans a wide range from being flat ( $\geq -0.1$) to very steep ($\leq -1.0$). We find that the strongest leakers in our sample show flat $\alpha^{\mathrm{3GHz}}_\mathrm{6GHz}$, weak leakers have $\alpha^{\mathrm{3GHz}}_\mathrm{6GHz}$ close to normal star-forming galaxies, and non-leakers are characterized by steep $\alpha^{\mathrm{3GHz}}_\mathrm{6GHz}$. We argue that a combination of young ages, free-free absorption, and a flat cosmic-ray energy spectrum can altogether lead to a flat $\alpha^{\mathrm{3GHz}}_\mathrm{6GHz}$ for strong leakers. Non-leakers are characterized by steep spectra which can arise due to break/cutoff at high frequencies. Such a cutoff in the spectrum can arise in a single injection model of CRs characteristic of galaxies which have recently stopped star formation. Such a relation between $\alpha^{\mathrm{3GHz}}_\mathrm{6GHz}$ and $f_\mathrm{esc}^\mathrm{LyC}$ hints at the interesting role of supernovae, CRs, and magnetic fields in facilitating the escape (and/or the lack) of LyC photons.Comment: 25 pages, 14 figures, 3 tables, Submitted to Astronomy & Astrophysic