Comment on "Electron transport through correlated molecules computed using the time-independent Wigner function: Two critical tests"

The many electron correlated scattering (MECS) approach to quantum electronic transport was investigated in the linear response regime [I. Baldea and H. Koeppel, Phys. Rev. B. 78, 115315 (2008)]. The authors suggest, based on numerical calculations, that the manner in which the method imposes boundary conditions is unable to reproduce the well-known phenomena of conductance quantization. We introduce an analytical model and demonstrate that conductance quantization is correctly obtained using open system boundary conditions within the MECS approach.Comment: 18 pages, 4 figures. Physical Review B, to appea

'Doing the hard yards': Carer and provider focus group perspectives of accessing Aboriginal childhood disability services

Background: Despite a high prevalence of disability, Aboriginal Australians access disability services in Australia less than non-Aboriginal Australians with a disability. The needs of Aboriginal children with disability are particularly poorly understood. They can endure long delays in treatment which can impact adversely on development. This study sought to ascertain the factors involved in accessing services and support for Aboriginal children with a disability. Methods. Using the focus group method, two community forums, one for health and service providers and one for carers of Aboriginal children with a disability, were held at an Aboriginal Community Controlled Health Service (ACCHS) in the Sydney, metropolitan area of New South Wales, Australia. Framework analysis was applied to qualitative data to elucidate key issues relevant to the dimensions of access framework. Independent coding consistency checks were performed and consensus of analysis verified by the entire research team, several of whom represented the local Aboriginal community. Results: Seventeen health and social service providers representing local area government and non-government-funded health and social service organisations and five carers participated in two separate forums between September and October 2011. Lack of awareness of services and inadequate availability were prominent concerns in both groups despite geographic proximity to a major metropolitan area with significant health infrastructure. Carers noted racism, insufficient or non-existent services, and the need for an enhanced role of ACCHSs and AHWs in disability support services. Providers highlighted logistical barriers and cultural and historical issues that impacted on the effectiveness of mainstream services for Aboriginal people. Conclusions: Despite dedicated disability services in an urban community, geographic proximity does not mitigate lack of awareness and availability of support. This paper has enumerated a number of considerations to address provision of disability services in an urban Australian Aboriginal community including building expertise and specialist capacity within Aboriginal Health Worker positions and services. Increasing awareness of services, facilitating linkages and referrals, eliminating complexities to accessing support, and working with families and Aboriginal community organisations within a framework of resilience and empowerment to ensure a relevant and acceptable model are necessary steps to improving support and care for Aboriginal children with a disability. © 2013 DiGiacomo et al.; licensee BioMed Central Ltd

Interacting With Providers: An Intersectional Exploration of the Experiences of Carers of Aboriginal Children With a Disability

© The Author(s) 2018. Intersectionality has potential to create new ways to describe disparities and craft meaningful solutions. This study aimed to explore Aboriginal carers’ experiences of interactions with health, social, and education providers in accessing services and support for their child. Carers of Aboriginal children with a disability were recruited from an Australian metropolitan Aboriginal community-controlled health service. In-depth, semistructured interviews were conducted with 19 female carers. Intersectionality was applied as an analytical framework due to the inherent power differentials for Aboriginal Australians and carers for people with a disability. Marginalization and a lack of empowerment were evident in the experiences of interactions with providers due to cultural stereotypes and racism, lack of cultural awareness and sensitivity, and poverty and homelessness. Community-led models of care can help overcome the intersectional effects of these identities and forms of oppression in carers’ interactions with providers and enhance access to care

Experiences and needs of carers of Aboriginal children with a disability: A qualitative study

© 2017 The Author(s). Background: Australian parents/carers of a person with a disability experience higher rates of depression, more financial stress, and are twice as likely to be in poor physical health than the general population. Aboriginal and Torres Strait Islander peoples experience worse health, social and economic outcomes than other Australians, and those with a disability face 'double disadvantage'. This study aimed to better understand the experiences and needs of parents/carers/families of Aboriginal children with a disability. Methods: Semi-structured in-depth interviews were conducted with parents or primary carers of Aboriginal children aged zero-eight with disability. Interviews were analysed using thematic analysis. Results: Nineteen women (sixteen mothers and three grandmothers) were interviewed. More than half were lone carers (without a partner or spouse). Participants described their experiences, including challenges and facilitators, to providing and accessing care, impacts on their health and wellbeing, and associated economic and non-economic costs of caregiving. Financial strain and social isolation was particularly prominent for lone carers. Conclusions: Tailoring services to the needs of carers of Aboriginal children with a disability means supporting kinship caregiving, facilitating engagement with other Aboriginal families, and streamlining services and systems to mitigate costs. The experiences described by our participants depict an intersection of race, socio-economic status, gender, disability, and caregiving. Services and funding initiatives should incorporate such intersecting determinants in planning and delivery of holistic care

Navigating the journey of Aboriginal childhood disability: a qualitative study of carers' interface with services

© 2016 The Author(s) Background: The disadvantage experienced by Aboriginal and Torres Strait Islander children with a disability is well recognized. The long term consequences of failing to address disability on health, education and employment underlies the importance of early intervention. Caregivers experience a disproportionate burden and have challenges accessing services. The aim of this study was to describe the carer journey of accessing support and services. Methods: We conducted in-depth semi-structured interviews with nineteen parents and carers of Aboriginal children aged 0-8 years. The children were patients at a child developmental clinic at a metropolitan area Aboriginal health service in Eastern Australia. Interpretive phenomenological analysis was applied to transcribed verbatim accounts. Results: Four themes were developed using the 'journey' metaphor to describe the carer pathway of accessing support and services at the community, service and policy levels. Themes included 1) the need for increased signage within communities via community education, information and awareness, 2) wrong way signs, roundabouts and roadblocks encountered when accessing services, 3) alternate routes can facilitate the journey, and 4) incompatibility of inflexible bureaucratic road rules and lived realities. Conclusions: The challenges of caring for a child with a disability are indisputable and these can be compounded for people experiencing socio-economic disadvantage and marginalisation. Overcoming challenges to service access faced by carers of Aboriginal children with a disability will require investment in community, services and policy to tailor culturally appropriate models of care

Vertex corrections in localized and extended systems

Within many-body perturbation theory we apply vertex corrections to various closed-shell atoms and to jellium, using a local approximation for the vertex consistent with starting the many-body perturbation theory from a DFT-LDA Green's function. The vertex appears in two places -- in the screened Coulomb interaction, W, and in the self-energy, \Sigma -- and we obtain a systematic discrimination of these two effects by turning the vertex in \Sigma on and off. We also make comparisons to standard GW results within the usual random-phase approximation (RPA), which omits the vertex from both. When a vertex is included for closed-shell atoms, both ground-state and excited-state properties demonstrate only limited improvements over standard GW. For jellium we observe marked improvement in the quasiparticle band width when the vertex is included only in W, whereas turning on the vertex in \Sigma leads to an unphysical quasiparticle dispersion and work function. A simple analysis suggests why implementation of the vertex only in W is a valid way to improve quasiparticle energy calculations, while the vertex in \Sigma is unphysical, and points the way to development of improved vertices for ab initio electronic structure calculations.Comment: 8 Pages, 6 Figures. Updated with quasiparticle neon results, extended conclusions and references section. Minor changes: Updated references, minor improvement

Freshly Formed Dust in the Cassiopeia A Supernova Remnant as Revealed by the Spitzer Space Telescope

We performed Spitzer Infrared Spectrograph mapping observations covering nearly the entire extent of the Cassiopeia A supernova remnant (SNR), producing mid-infrared (5.5-35 micron) spectra every 5-10". Gas lines of Ar, Ne, O, Si, S and Fe, and dust continua were strong for most positions. We identify three distinct ejecta dust populations based on their continuum shapes. The dominant dust continuum shape exhibits a strong peak at 21 micron. A line-free map of 21 micron-peak dust made from the 19-23 micron range closely resembles the [Ar II], [O IV], and [Ne II] ejecta-line maps implying that dust is freshly formed in the ejecta. Spectral fitting implies the presence of SiO2, Mg protosilicates, and FeO grains in these regions. The second dust type exhibits a rising continuum up to 21 micron and then flattens thereafter. This ``weak 21 micron'' dust is likely composed of Al2O3 and C grains. The third dust continuum shape is featureless with a gently rising spectrum and is likely composed of MgSiO3 and either Al2O3 or Fe grains. Using the least massive composition for each of the three dust classes yields a total mass of 0.02 Msun. Using the most-massive composition yields a total mass of 0.054 Msun. The primary uncertainty in the total dust mass stems from the selection of the dust composition necessary for fitting the featureless dust as well as 70 micron flux. The freshly formed dust mass derived from Cas A is sufficient from SNe to explain the lower limit on the dust masses in high redshift galaxies.Comment: 8 figures: Accepted for the publication in Ap

Particle Impact Analysis of Bulk Powder During Pneumatic Conveyance

Fragmentation of powders during transportation is a common problem for manufacturers of food and pharmaceutical products. We illustrate that the primary cause of breakage is due to inter-particle collisions, rather than particle-wall impacts, and provide a statistical mechanics model giving the number of collisions resulting in fragmentation