1,192 research outputs found

    What can the SEDs of first hydrostatic core candidates reveal about their nature?

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    The first hydrostatic core (FHSC) is the first stable object to form in simulations of star formation. This stage has yet to be observed definitively, although several candidate FHSCs have been reported. We have produced synthetic spectral energy distributions (SEDs) from 3D hydrodynamical simulations of pre-stellar cores undergoing gravitational collapse for a variety of initial conditions. Variations in the initial rotation rate, radius and mass lead to differences in the location of the SED peak and far-infrared flux. Secondly, we attempt to fit the SEDs of five FHSC candidates from the literature and five newly identified FHSC candidates located in the Serpens South molecular cloud with simulated SEDs. The most promising FHSC candidates are fitted by a limited number of model SEDs with consistent properties, which suggests the SED can be useful for placing constraints on the age and rotation rate of the source. The sources we consider most likely to be in FHSC phase are B1-bN, CB17-MMS, Aqu-MM1 and Serpens South candidate K242. We were unable to fit SerpS-MM22, Per-Bolo 58 and Chamaeleon-MMS1 with reasonable parameters, which indicates that they are likely to be more evolved.Comment: 26 pages, 28 figures. Accepted for publication in MNRA

    Children and young people\u27s self-reported experiences of asthma and self-management nursing strategies: An integrative review

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    Aim: To explore children and young people\u27s (CYP) (5–24 years of age) self-reported experiences of asthma self-management strategies (ASMS) with nursing involvement across various settings. Background: Childhood asthma is an increasingly significant health issue, highlighting the importance of acquiring self-management skills to optimise future health outcomes. Registered nurses play a pivotal role in delivering appropriate, personalized self-management support. Methods: This integrative review searched four electronic databases: Cumulated Index to Nursing and Allied Health Literature via Elton B. Stephens Company, Medical Literature Analysis and Retrieval System Online (MEDLINE), Object, View and Interactive Design (OVID), and PubMed, that followed the Preferred Reporting Items for Systematic Reviews and Meta-Analysis flowchart. Included studies were critically appraised using the Joanna Briggs Institute critical appraisal tools. Braun and Clarks thematic analysis was used to generate themes, and sub-themes. Findings: Fifteen studies were included for review. Thematic analysis generated three themes being healthy literacy; health and wellbeing; and tools and working together. Conclusions: Asthma continues to have negative physical, psychological, and social implications among CYP. CYP are both willing and capable of engaging in ASMS and learning self-management skills, however, continue to have unmet self-management needs. Implications to practice: Strategies must bolster health literacy, improve physical and psychological health, and harness interactive, youth-centric, and informative tools to facilitate communication and decrease the burden of self-management. Applications pose a promising avenue for self-management support. This age group remains under-explored and future research should enable meaningful engagement with CYP to better understand their perspectives and improve strategy success

    Dystrophin Gene Mutation Location and the Risk of Cognitive Impairment in Duchenne Muscular Dystrophy

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    Contains fulltext : 88828.pdf (publisher's version ) (Open Access)BACKGROUND: A significant component of the variation in cognitive disability that is observed in Duchenne muscular dystrophy (DMD) is known to be under genetic regulation. In this study we report correlations between standardised measures of intelligence and mutational class, mutation size, mutation location and the involvement of dystrophin isoforms. METHODS AND RESULTS: Sixty two male subjects were recruited as part of a study of the cognitive spectrum in boys with DMD conducted at the Sydney Children's Hospital (SCH). All 62 children received neuropsychological testing from a single clinical psychologist and had a defined dystrophin gene (DMD) mutation; including DMD gene deletions, duplications and DNA point mutations. Full Scale Intelligence Quotients (FSIQ) in unrelated subjects with the same mutation were found to be highly correlated (r = 0.83, p = 0.0008), in contrast to results in previous publications. In 58 cases (94%) it was possible to definitively assign a mutation as affecting one or more dystrophin isoforms. A strong association between the risk of cognitive disability and the involvement of groups of DMD isoforms was found. In particular, improvements in the correlation of FSIQ with mutation location were identified when a new classification system for mutations affecting the Dp140 isoform was implemented. SIGNIFICANCE: These data represent one of the largest studies of FSIQ and mutational data in DMD patients and is among the first to report on a DMD cohort which has had both comprehensive mutational analysis and FSIQ testing through a single referral centre. The correlation between FSIQ results with the location of the dystrophin gene mutation suggests that the risk of cognitive deficit is a result of the cumulative loss of central nervous system (CNS) expressed dystrophin isoforms, and that correct classification of isoform involvement results in improved estimates of risk

    Strong Continuum-continuum Couplings In The Direct Ionization Of Ar And He Atoms By 6-MeV/u U38+ And Th38+ Projectiles

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    Doubly differential cross sections have been measured as a function of the electron energy and observation angle for electron emission following collisions of 6-MeV/u U38+ and Th38+ on He and Ar. The electron-emission data show an enhancement at forward angles and a decrease at backward angles with respect to scaled-cross-section results based on the Born approximation. Comparison with classical-trajectory Monte Carlo calculations suggests that the deviation from the Born approximation can be explained by continuum-continuum couplings. By comparing with previously published data, we found that the forward enhancement as well as the backward decrease follow a q/vp (q,vp are the projectile charge and velocity) scaling. © 1989 The American Physical Society

    Mitigation of carbon using Atriplex nummularia revegetation

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    The use of abandoned or marginally productive land to mitigate greenhouse gas emissions may avoid competition with food and water production. Atriplex nummularia Lindl. is a perennial shrub commonly established for livestock forage on saline land, however, its potential for carbon mitigation has not been systematically evaluated. Similarly, although revegetation is an allowable activity to mitigate carbon within Article 3.4 of the United Nations Framework Convention on Climate Change's Kyoto Protocol, there is a paucity of information on rates of carbon mitigation in soils and biomass through this mechanism. For six sites where A. nummularia had been established across southern Australia four were used to assess changes in soil carbon storage and four were used to develop biomass carbon sequestration estimates. A generalised allometric equation for above and below ground biomass was developed, with a simple crown volume index explaining 81% of the variation in total biomass. There were no significant differences in soil organic carbon storage to 0.3 m or 2 m depth compared to existing agricultural land-use. Between 2.2 and 8.3 Mg C ha−1 or 0.2–0.6 Mg C ha−1 yr−1 was sequestered in above and below ground biomass and this translates to potential total sequestration of 1.1–3.6 Tg C yr−1 on saline land across Australia. Carbon income and forage grazing may thus provide a means to finance the stabilization of compromised land
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