1,183 research outputs found
The impact of metallicity and dynamics on the evolution of young star clusters
The early evolution of a dense young star cluster (YSC) depends on the
intricate connection between stellar evolution and dynamical processes. Thus,
N-body simulations of YSCs must account for both aspects. We discuss N-body
simulations of YSCs with three different metallicities (Z=0.01, 0.1 and 1
Zsun), including metallicity-dependent stellar evolution recipes and
metallicity-dependent prescriptions for stellar winds and remnant formation. We
show that mass-loss by stellar winds influences the reversal of core collapse.
In particular, the post-collapse expansion of the core is faster in metal-rich
YSCs than in metal-poor YSCs, because the former lose more mass (through
stellar winds) than the latter. As a consequence, the half-mass radius expands
more in metal-poor YSCs. We also discuss how these findings depend on the total
mass and on the virial radius of the YSC. These results give us a clue to
understand the early evolution of YSCs with different metallicity.Comment: to appear in "Massive Young Star Clusters Near and Far: From the
Milky Way to Reionization", 2013 Guillermo Haro Conference, Eds. Y. D. Mayya,
D. Rosa-Gonzalez & E. Terlevich, INAOE and AMC. 4 pages, 2 figure
Poverty and disability: A vicious circle? Evidence from Afghanistan and Zambia
Disability and poverty have a complex and interdependent relationship. It is commonly understood that persons with disabilities are more likely to be poor and that poverty may contribute to sustaining disability. This interdependency is revealed not only through an examination of poverty in terms of income but also on a broader scale through other poverty related dimensions. Just how robust is this link? This paper compares data collected from household surveys in Afghanistan and Zambia, and explores the potential link between multidimensional poverty and disability. We find evidence of lower access to health care, education and labour market for people with disabilities, whatever is the disability status, but poverty measured by an asset index is not statistically different between people with and without disabilities
Near-surface eddy dynamics in the southern ocean
The Antarctic Circumpolar Current (ACC) is a crucial component of the global ocean conveyor belt, acting as a zonal link among the major ocean basins but, to some extent, limiting meridional exchange and tending to isolate the ocean south of it from momentum and heat income. In this work we investigate one of the most important mechanisms contributing to the poleward transfer of properties in the Southern Ocean, that is the eddy component of the dynamics. For this particular purpose, observations obtained from near-surface drifters have been used: they represent a very useful data set to analyse the eddy field because of their ability to catch a large number of scales of motion while providing a quasi-synoptic coverage of the investigated area. Estimates of the eddy heat and momentum fluxes are carried out using data taken from the Global Drifter Program databank; they refer to Surface Velocity Program drifter trajectories collected in the area south of 35°S between 1995 and 2006. Eddy kinetic energies, variance ellipses, momentum and heat fluxes have been calculated using the pseudo-Eulerian method, showing patterns in good agreement with those present in the literature based on observational and model data, although there are some quantitative differences. The eddy fluxes have been separated into their rotational and divergent portions, the latter being responsible for the meridional transports. The associated zonal and depth-exponentially integrated meridional heat transport exhibits values spanning over a range between -0.4 PW and -1.1 PW in the ACC region, consistent with previous estimates. © 2011 M. Trani et al
Development and Validation of the 34-Item Disability Screening Questionnaire (DSQ-34) for Use in Low and Middle Income Countries Epidemiological and Development Surveys
Background: Although 80% of persons with disabilities live in low and middle-income countries, there is still a lack of comprehensive, cross-culturally validated tools to identify persons facing activity limitations and functioning difficulties in these settings. In absence of such a tool, disability estimates vary considerably according to the methodology used, and policies are based on unreliable estimates Methods and Findings: The Disability Screening Questionnaire composed of 27 items (DSQ-27) was initially designed by a group of international experts in survey development and disability in Afghanistan for a national survey. Items were selected based on major domains of activity limitations and functioning difficulties linked to an impairment as defined by the International Classification of Functioning, Disability and Health. Face, content and construct validity, as well as sensitivity and specificity were examined. Based on the results obtained, the tool was subsequently refined and expanded to 34 items, tested and validated in Darfur, Sudan. Internal consistency for the total DSQ-34 using a raw and standardized Cronbach’s Alpha and within each domain using a standardized Cronbach’s Alpha was examined in the Asian context (India and Nepal). Exploratory factor analysis (EFA) using principal axis factoring (PAF) evaluated the lowest number of factors to account for the common variance among the questions in the screen. Test-retest reliability was determined by calculating intraclass correlation (ICC) and inter-rater reliability by calculating the kappa statistic; results were checked using Bland-Altman plots. The DSQ-34 was further tested for standard error of measurement (SEM) and for the minimum detectable change (MDC). Good internal consistency was indicated by Cronbach’s Alpha of 0.83/0.82 for India and 0.76/0.78 for Nepal. We PLOS ONE | DOI:10.1371/journal.pone.0143610 December 2, 2015 1 / 14 OPEN ACCESS Citation: Trani J-F, Babulal GM, Bakhshi P (2015) Development and Validation of the 34-Item Disability Screening Questionnaire (DSQ-34) for Use in Low and Middle Income Countries Epidemiological and Development Surveys. PLoS ONE 10(12): e0143610. doi:10.1371/journal.pone.0143610 Editor: Philip C Hill, University of Otago, NEW ZEALAND Received: May 29, 2015 Accepted: November 6, 2015 Published: December 2, 2015 Copyright: © 2015 Trani et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Data Availability Statement: All relevant data are within the paper and its Supporting Information files. Funding: The authors received no specific funding for this work. Competing Interests: The authors have declared that no competing interests exist. confirmed our assumption for EFA using the Kaiser-Meyer-Olkin measure of sampling well above the accepted cutoff of 0.40 for India (0.82) and Nepal (0.82). The criteria for Bartlett’s test of sphericity were also met for both India (\u3c .001) and Nepal (\u3c .001). Estimates of reliability from the two countries reached acceptable levels of ICC of 0.75 (p\u3c0.001) for India of 0.77 for Nepal (p\u3c0.001) and good strength of agreement for weighted kappa (respectively0.77 and 0.79). The SEM/MDC was 0.80/2.22 for India and 0.96/2.66 for Nepal indicating a smaller amount of measurement error in the screen. Conclusions: In Nepal and India, the DSQ-34 shows strong psychometric properties that indicate that it effectively discriminates between persons with and without disabilities. This instrument can be used in association with other instruments for the purpose of comparing health outcomes of persons with and without disabilities in LMICs
Education of children with disabilities in New Delhi: When does exclusion occur?
In the new Sustainable Development Goal 4, quality of education defined as equity and inclusion alongside traditional learning outcomes, has replaced the narrow goal of access to primary education stipulated in the Millennium Development Goal 2. Since 2000, considerable progress has been made towards improving access to school for children in India, yet questions remain regarding not just children with disabilities\u27 access and acquisition of basic learning skills, but also completion of learning cycles. Methods and findings Between November, 2, 2011 and June 20th 2012, we interviewed 1294 households about activity limitations and functioning difficulties associated with a health problem among all family members using a validated screening instruments, as well as questions about access, retention and barriers to education. We found that vulnerable children, particularly children with disabilities are less likely to start school and more likely to drop out of school earlier and before completing their high school education than non-disabled children, showing that the learning process is not inclusive in practice. The gap is wider for girls, economically deprived children, or children from households where the head is uneducated. Conclusions Firstly, in order to fill the existing knowledge gap on education of children with disabilities in line with SDG4, not only is there a necessity for relevant data with regards to learning outcomes, but also an urgent requirement for more innovative information pertaining to relational aspects of learning that reflect inclusion. Secondly, a stronger understanding of the implications of early assessment would further promote equity in education. Finally, research should tackle learning as a complex and dynamic phenomenon. Education needs to fulfil its instrumental value, but must also re-claim its intrinsic value that often gets watered down in the journey from policies to implementation
Screening for developmental disorders in 3- and 4-year-old italian children: a preliminary study
BACKGROUND:
The "Osserviamo" project, coordinated by the Municipality of Rome and the Department of Pediatrics and Child Neuropsychiatry of Sapienza University, aimed to validate an Italian version of the Ages and Stages Questionnaire-3 and to collect, for the first time in Italy, data on developmental disorders in a sample of 4,000 children aged 3 and 4 years. The present paper presents the preliminary results of the "Osserviamo" project.
METHODS:
600 parents of children between 39 and 50 months of age (divided in two age stages: 42 and 48 months) were contacted from 15 kindergarden schools.
RESULTS:
23.35% of the whole sample scored in the risk range of at least one developmental area of the Ages and Stages Questionnaire-3rd Edition (ASQ-3) and 7.78% scored in the clinical range. Specifically, 23.97% of the children in the 42-month age stage scored in the risk range and 5.79% scored in the clinical range. Males scored lower than females in the fine motor skills and personal-social development domains. Moreover, 22.79% of the children in the 48-month age stage scored in the risk range, while 9.55% scored in the clinical range. Males scored lower than females in fine motor skills.
CONCLUSION:
Italian validation of the ASQ-3 and recruitment of all 4,000 participants will allow these data on the distribution of developmental disorders to be extended to the general Italian pediatric population. One main limitation of the study is the lack of clinical confirmation of the data yielded by the screening programme, which the authors aim to obtain in later stages of the study
Il Cosim per il restauro generale della basilica di S. Maria di Collemaggio a L'Aquila
L’approccio metodologico sviluppato nell’ambito della modellazione informativa BIM a servizio della progettazione cantieristica (Co.S.I.M.) ha trovato riscontro e, conseguentemente, validazione, nell’applicazione delle metodologie e degli strumenti sviluppati nell’ambito di casi di studio reali. Da questo punto di vista, la ricerca dipartimentale ha potuto indagare, tra gli altri, un importante caso di studio che ha permesso una effettiva integrazione tra le diverse discipline progettuali e tra i diversi ambiti di ricerca applicati alla modellazione informativa del patrimonio architettonico. Si tratta del restauro generale della Basilica di Santa Maria di Collemaggio a L’Aquila. Particolare attenzione è stata posta nell’analisi dei livelli di dettaglio della modellazione sia dal punto di vista grafico che informativo. La necessaria integrazione delle diverse discipline nell’ambito della progettazione di un intervento di tale complessità , ha portato a valutare, per ogni disciplina, quale possa essere la rappresentazione maggiormente efficiente degli elementi caratterizzanti la basilica e il restauro nel loro contesto. In quest’ambito si inserisce anche la progettazione cantieristica la quale ha contribuito alle determinazioni dei livelli di dettaglio in funzione delle necessità di progettazione funzionale-spaziale e tecnologico-produttiva, oltre che operativa, del sistema cantieristico
Il progetto ergotecnico degli interventi sul costruito. La modellazione informativa Cosim e i suoi strumenti
La progettazione ergotecnica di un intervento, al pari delle altre discipline progettuali, si sviluppa nell’ambito dei progressivi livelli di approfondimento connotanti un processo edilizio; il progetto di un sistema cantieristico, tuttavia, non si esaurisce con la gara di appalto ma risulta essere in continuo divenire anche durante la fase di esecuzione di un’opera.
Durante ciascuna fase di progettazione, lo scambio informativo tra la progettazione ergotecnica e gli altri ambiti progettuali è di fondamentale importanza per sviluppare una maggiore consapevolezza di tutto il pool di professionisti relativamente alla concreta fattibilità delle opere da loro progettate ed evitare incongruenze, specialmente nell’ambito di interventi sull’ambiente costruito. Come ormai noto il Building Information Modeling (BIM) è il metodo che meglio consente di interfacciare in maniera efficace i diversi ambiti progettuali con la progettazione ergotecnica che, in ambito BIM, si esprime come Construction Site Information Modeling (Co.S.I.M.); ciò al fine di ottenere una vera e propria progettazione integrata.
Al fine di migliorare il metodo CoSIM per i diversi soggetti che interagiscono con esso, la ricerca ha messo a punto specifici strumenti a supporto delle scelte progettuali ergotecniche da effettuare, avvalendosi di casi di studio riferiti a interventi sul patrimonio storico-architettonico esistente. Sono stati così realizzati: un template utile alla individuazione delle criticità di contesto, una serie di librerie di macchine, attrezzature e apprestamenti di cantiere parametrizzati e corredati da un loro patrimonio informativo, una serie di configurazioni spaziali tipiche utili alla scelta semi automatizzata degli apprestamenti di cantiere da inserire per la risoluzione di interferenze e alcuni database per la scelta semiautomatizzata di macchine e attrezzature di cantiere unitamente alla verifica di esistenza di modelli commerciali rispondenti alle esigenze del progetto
The ominous fate of exomoons around hot Jupiters in the high-eccentricity migration scenario
All the giant planets in the Solar system host a large number of natural satellites. Moons in extrasolar systems are difficult to detect, but a Neptune-sized exomoon candidate has been recently found around a Jupiter-sized planet in the Kepler-1625b system. Due to their relative ease of detection, hot Jupiters (HJs), which reside in close orbits around their host stars with a period of a few days, may be very good candidates to search for exomoons. It is still unknown whether the HJ population can host (or may have hosted) exomoons. One suggested formation channel for HJs is high-eccentricity migration induced by a stellar binary companion combined with tidal dissipation. Here, we investigate under which circumstances an exomoon can prevent or allow high-eccentricity migration of a HJ, and in the latter case, if the exomoon can survive the migration process. We use both semi-analytic arguments, as well as direct N-body simulations including tidal interactions. Our results show that massive exomoons are efficient at preventing high-eccentricity migration. If an exomoon does instead allow for planetary migration, it is unlikely that the HJ formed can host exomoons since the moon will either spiral on to the planet or escape from it during the migration process. A few escaped exomoons can become stable planets after the Jupiter has migrated, or by tidally migrating themselves. The majority of the exomoons end up being ejected from the system or colliding with the primary star and the host planet. Such collisions might none the less leave observable features, such as a debris disc around the primary star or exorings around the close-in giant
Can alexithymia be assessed through an interview in adolescents? The Toronto Structured Interview for Alexithymia: Reliability, concurrent validity, discriminant validity, and relationships with emotional-behavioral symptoms
Alexithymia is connected to adolescents' psychopathology, but the current methods of assessment present limitations. The Toronto Structured Interview for Alexithymia (TSIA) was developed to overcome the limits of the main used self-rating scale in adults, but no studies investigated its feasibility with adolescents. This study involved 95 community adolescents aged 12-19 years. Adolescents were assessed with the TSIA, the 20-item Toronto Alexithymia Scale (TAS-20), the Verbal Comprehension Index of the WISC-IV for verbal skills, and the Child Behavior Checklist and Youth Self Report for emotional-behavioral symptoms. The aims were to investigate the TSIA internal consistency, concurrent validity with the TAS-20, discriminant validity with participants' verbal skills, and relationships with emotional-behavioral symptoms. TSIA showed good internal consistency, concurrent validity with the TAS-20 (except for factor DDF), and independence by participants' verbal skills, but few relationships with emotional-behavioral symptoms. In conclusion, TSIA showed some good psychometric proprieties but little convergence with research findings obtained with the TAS-20, suggesting the need for further research to check the feasibility of using the TSIA with adolescents. Meanwhile, a precautionary multi-method assessment of alexithymia is recommended
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