On the effect of cosmological inflow on turbulence and instability in galactic discs

We analyse the evolution of turbulence and gravitational instability of a galactic disc in a quasi-steady state governed by cosmological inflow. We focus on the possibility that the coupling between the in-streaming gas and the disc is maximal, e.g., via dense clumps, and ask whether the streams could be the driver of turbulence in an unstable disc with a Toomre parameter Q~1. Our fiducial model assumes an efficiency of ~0.5 per dynamical time for the decay of turbulence energy, and ~0.02 for each of the processes that deplete the disc gas, i.e., star formation, outflow, and inflow within the disc into a central bulge. In this case, the in-streaming drives a ratio of turbulent to rotation velocity sigma/V~0.2-0.3, which at z~2 induces an instability with Q~1, both as observed. However, in conflict with observations, this model predicts that sigma/V remains constant with time, independent of the cosmological accretion rate, because mass and turbulence have the same external source. Such strongly coupled cosmological inflow tends to stabilize the disc at low z, with Q ~ a few, which may be consistent with observations. The instability could instead be maintained for longer, with a properly declining sigma/V, if it is self-regulated to oscillations about Q~1 by a duty cycle for disc depletion. However, the 'off' phases of this duty cycle become long at low z, which may be hard to reconcile with observations. Alternatively, the coupling between the in-streaming gas and the disc may weaken in time, reflecting an evolving nature of the accretion. If, instead, that coupling is weak at all times, the likely energy source for self-regulated stirring up of the turbulence is the inflow within the disc down the potential gradient (studied in a companion paper).Comment: 14 pages, 1 table. Accepted for publication in Monthly Notices of the Royal Astronomical Society. Minor changes to match accepted versio

COVID-19 IDD: A global survey exploring the impact of COVID-19 on individuals with intellectual and developmental disabilities and their caregivers

Background: This protocol outlines research to explore the impact of coronavirus disease 2019 (COVID-19) on individuals who have intellectual and developmental disabilities and their caregivers. Evidence suggests that people with intellectual and developmental disabilities experience disparities in healthcare access and utilisation. This disparity was evident early in the pandemic when discussions arose regarding the potential exclusion of this population to critical care. Methods: An anonymous online survey will be conducted with caregivers, both family members and paid staff, to explore the impact of COVID-19 on this population in terms of demographics, living arrangements, access to services, the impact of social distancing, and also carer wellbeing. The survey will be developed by the research team, many of whom are experts in intellectual disability within their own jurisdictions. Using back-translation our team will translate the survey for distribution in 16 countries worldwide for international comparison. The survey team have extensive personal and professional networks in intellectual disability and will promote the survey widely on social media with the support of local disability and advocacy agencies. Statistical descriptive and comparative analyses will be conducted. Ethical approval has been obtained for this study from University College Dublin’s Human Research Ethics Committee (HS-20-28-Linehan). Dissemination: Study findings will be prepared in a number of formats in order to meet the needs of different audiences. Outputs will include academic papers, lessons learned paper, practice guidelines, reports, infographics and video content. These outputs will be directed to families, frontline and management delivering disability services, national-level policy makers, healthcare quality and delivery authorities, national pandemic organisations and international bodies

Species abundance distributions: moving beyond single prediction theories to integration within an ecological framework

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75247/1/j.1461-0248.2007.01094.x.pd

The modelling of feedback in star formation simulations

This document is the Accepted Manuscript version of the following article: James E. Dale, ‘The modelling of feedback in star formation simulations’, New Astronomy Reviews, Vol. 68, pp. 1-33, October 2015. This article is distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives License (http://creativecommons.org/licenses/by-nc-nd/4.0/ ), which permits non-commercial re-use, distribution, and reproduction in any medium, provided the original work is properly cited, and is not altered, transformed, or built upon in any way. The final, published version is available online at doi:https://doi.org/10.1016/j.newar.2015.06.001. © 2015 Elsevier B.V. All rights reserved.I review the current state of numerical simulations of stellar feedback in the context of star formation at scales ranging from the formation of individual stars to models of galaxy formation including cosmic reionisation. I survey the wealth of algorithms developed recently to solve the radiative transfer problem and to simulate stellar winds, supernovae and protostellar jets. I discuss the results of these simulations with regard to star formation in molecular clouds, the interaction of different feedback mechanisms with each other and with magnetic fields, and in the wider context of galactic- and cosmological-scale simulations.Peer reviewe

Book ReviewRe-examining Psychology: Critical Perspectives and African Insightsby: Len T Holdstock (2000)

Available from: Routledge, 11 New Fetter Lane, London EC4P 4EE, United Kingdom, www.routledge.co.ukHardcover: ISBN 0 4151 8792 3, GB£50.00Journal of Psychology in Africa 2004, 14(1): 8

Revista de educación

Se estudia el proceso de iniciación del estudiante en la enseñanza secundaria. En primer lugar se analiza el paso de la enseñanza primaria a la secundaria. Se destaca que es una realidad manifiesta el gran vacío reinante en la actualidad en cuanto a los enlaces didácticos que deberían existir entre la Primera y la Segunda enseñanza. En segundo lugar se plantea la cuestión de qué edad es la más adecuada para empezar los estudios de la segunda enseñanza. Se analizan las respuestas de personas competentes y centros responsables. La mayor proporción se decanta por que este paso se produzca una vez se hayan cumplido los doce años. A continuación se ponen de manifiesto las principales dificultades por discontinuidad. El niño que a la edad de los diez años abandona la escuela primaría y el proceso educativo que ella representa, cierra de golpe el cauce natural de desarrollo. Si el proceso educativo tuviera continuidad, por lo menos durante los primeros cursos del Bachillerato, el trastorno se reduciría a la mínima expresión. Se hace mención a otros aspectos como el grado de desarrollo mental. Está bien comprobado que el grado de desarrollo mental, necesario para afrontar de manera satisfactoria las disciplinas propias del Bachillerato, es deficiente en el 90 por 100 de los casos en niños comprendidos entre las edades de nueve y diez años. Respecto a la memoria, considerada la facultad la más importante de nuestra vida psíquica, no puede ofrecer en esta edad ninguna garantía de estructuración global para el encadenamiento lógico de las adquisiciones psíquicas. Otras cualidades que se cuestionan son la atención, la imaginación, la asociación de ideas, la comprensión, el juicio y el raciocinio y el análisis mental. Se hace especial mención al problema de la escritura y de la lectura, la caligrafía, los ejercicios por escrito, la ortografía y al estudio de las matemáticas. Se concluye con la iniciación a la segunda enseñanza propiamente dicha.Ministerio Educación CIDEBiblioteca de Educación del Ministerio de Educación, Cultura y Deporte; Calle San Agustín, 5 - 3 Planta; 28014 Madrid; Tel. +34917748000; [email protected]

COVID-19 IDD: Findings from a global survey exploring family members’ and paid staff’s perceptions of the impact of COVID-19 on individuals with intellectual and developmental disabilities (IDD) and their caregivers.

Background: A growing body of evidence attests to the disproportionate impact of COVID-19 on persons with intellectual and developmental disabilities (IDD) during the pandemic. This study asked caregivers about their perceptions of how COVID-19 impacted them and the people they support. Method: An online survey was conducted in 12 countries during August-September 2020 and sought information on demographics, support practices, information and training, experiences of COVID-19, social distancing, and wellbeing, as measured by the DASS12. This study reports on 3,754 family members, direct support professionals, and managers who participated in the survey. Results: Caregivers observed increases in depression/anxiety, stereotyped behaviours, aggression towards others and weight gain in the person(s) they supported. They also reported difficulties supporting the person(s) to access healthcare.  Families reported reducing or ceasing employment and absorbed additional costs when supporting their family member. Direct support professionals experienced changes in staff shifts, staff absences, increased workload and hiring of casual staff. Caregivers’ wellbeing revealed high levels of stress, depression, and less so anxiety. The strongest predictor of wellbeing among families was observation of changes in mood in the person(s) they supported, while for direct support professionals, the strongest predictors of wellbeing were reorganisation of staff shifts and increases in new direct support staff.  Discussion: Findings support the contention of this population experiencing a disproportionate burden during the COVID-19 pandemic, reflecting historical inequities in access to healthcare and other human rights violations which are now protected under the United Nations Convention on the Rights of Persons with Disabilities

COVID-19 IDD: Findings from a global survey exploring family members' and paid staff's perceptions of the impact of COVID-19 on individuals with intellectual and developmental disabilities (IDD) and their caregivers

Background: A growing body of evidence attests to the disproportionate impact of COVID-19 on persons with intellectual and developmental disabilities (IDD) during the pandemic. This study asked caregivers about their perceptions of how COVID-19 impacted them and the people they support. Method: An online survey was conducted in 12 countries during August-September 2020 and sought information on demographics, support practices, information and training, experiences of COVID-19, social distancing, and wellbeing, as measured by the DASS12. This study reports on 3,754 family members, direct support professionals, and managers who participated in the survey. Results: Caregivers observed increases in depression/anxiety, stereotyped behaviours, aggression towards others and weight gain in the person(s) they supported. They also reported difficulties supporting the person(s) to access healthcare.  Families reported reducing or ceasing employment and absorbed additional costs when supporting their family member. Direct support professionals experienced changes in staff shifts, staff absences, increased workload and hiring of casual staff. Caregivers' wellbeing revealed high levels of stress, depression, and less so anxiety. The strongest predictor of wellbeing among families was observation of changes in mood in the person(s) they supported, while for direct support professionals, the strongest predictors of wellbeing were reorganisation of staff shifts and increases in new direct support staff.  Discussion: Findings support the contention of this population experiencing a disproportionate burden during the COVID-19 pandemic, reflecting historical inequities in access to healthcare and other human rights violations which are now protected under the United Nations Convention on the Rights of Persons with Disabilities