A fast and exact ww-stacking and ww-projection hybrid algorithm for wide-field interferometric imaging

The standard wide-field imaging technique, the $w$-projection, allows correction for wide-fields of view for non-coplanar radio interferometric arrays. However, calculating exact corrections for each measurement has not been possible due to the amount of computation required at high resolution and with the large number of visibilities from current interferometers. The required accuracy and computational cost of these corrections is one of the largest unsolved challenges facing next generation radio interferometers such as the Square Kilometre Array. We show that the same calculation can be performed with a radially symmetric $w$-projection kernel, where we use one dimensional adaptive quadrature to calculate the resulting Hankel transform, decreasing the computation required for kernel generation by several orders of magnitude, whilst preserving the accuracy. We confirm that the radial $w$-projection kernel is accurate to approximately 1% by imaging the zero-spacing with an added $w$-term. We demonstrate the potential of our radially symmetric $w$-projection kernel via sparse image reconstruction, using the software package PURIFY. We develop a distributed $w$-stacking and $w$-projection hybrid algorithm. We apply this algorithm to individually correct for non-coplanar effects in 17.5 million visibilities over a $25$ by $25$ degree field of view MWA observation for image reconstruction. Such a level of accuracy and scalability is not possible with standard $w$-projection kernel generation methods. This demonstrates that we can scale to a large number of measurements with large image sizes whilst still maintaining both speed and accuracy.Comment: 9 Figures, 19 Pages. Accepted to Ap

Characteristics of Nursing Doctoral Programs in The United States

The expansive growth of doctoral programs in the United States has necessitated a need to determine demographic attributes of the academic program, characteristics of the students, admission criteria, and curriculum patterns. Seventy-eight doctoral programs were sent a researcher-designed survey and 48 (62 per cent) responded. Results show an increasing shift away from clinical doctorates to the research doctorate, although few differences exist within the research focus of doctoral nursing programs. Consistent with previous reports in the literature, curricula are fairly standard and few differences were noted based on a number of criteria including geographic location, type of degree granted, Carnegie classification of the university, or by the length of time the program has been in existence. Discussion of these findings is included

Characteristics of Nursing Doctoral Programs in The United States

The expansive growth of doctoral programs in the United States has necessitated a need to determine demographic attributes of the academic program, characteristics of the students, admission criteria, and curriculum patterns. Seventy-eight doctoral programs were sent a researcher-designed survey and 48 (62 per cent) responded. Results show an increasing shift away from clinical doctorates to the research doctorate, although few differences exist within the research focus of doctoral nursing programs. Consistent with previous reports in the literature, curricula are fairly standard and few differences were noted based on a number of criteria including geographic location, type of degree granted, Carnegie classification of the university, or by the length of time the program has been in existence. Discussion of these findings is included

Hydrological modelling as a tool for interdisciplinary workshops on future drought

© 2018, © The Author(s) 2018. Transformative interdisciplinary methods and tools are required to address crucial water-related challenges facing societies in the current era of the Anthropocene. In a community-based study in the Limpopo basin of South Africa, physical and social science methods were brought together to run interdisciplinary workshops aimed at enhancing preparedness for possible future drought. To generate storylines for the workshops, relevant scenarios were modelled using a catchment-scale hydrological model, SHETRAN. Set up using freely available data, local knowledge, and narrative-based group interviews on past experiences of drought, the model acted as a locally-relevant tool for prompting discussions about potential future drought impacts, responses and preparedness, and to stimulate the production of community future narratives. In this paper, we discuss the elements involved in the modelling process: the building of the model through an interdisciplinary approach; setting up the model with limited data; and the translation of the model results into storylines for the workshops. We found that by using this methodology scientific grounding was given to the workshop storylines, and that the local context of the model and the engaging approach of creating narratives encouraged participant involvement in discussions about the future. The method of generating these future stories was an important process for the participants in developing their thinking about possible futures, preparedness and adaptation. In this paper we show how this alternative approach of using a hydrological model has benefits and we discuss the limitations and lessons of the approach for future interdisciplinary research

Water governance challenges in rural South Africa: exploring institutional coordination in drought management

Droughts have severe direct impacts on the livelihoods of rural populations. Thus, the management of water for communal agriculture and water supply should be well coordinated to enhance drought resilience. Notwithstanding the interrelations among water management institutions in South Africa, there are complexities in the way these institutions work together, both in preparation for, and during drought times. In this article, we examine the governance of water resources in South Africa with a view to understanding institutional coordination in drought management at different operational scales. Using a qualitative approach, the roles and relationships between water actors at the local and regional level were analyzed for their adequacy in building local level drought resilience in a village in the Limpopo province, South Africa. Key informant interviews conducted revealed operational drought management challenges that emanate from communication barriers, coordination inconsistences, and undefined, unclear actor roles and responsibilities during disasters. The top-down approach to disaster management, while of some value, currently constrains the effectiveness of the local-level institutions implementing local drought risk reduction efforts. Achieving more successful water and drought governance endeavors could be enhanced by greater and wider engagement with community-based actors and water management institutions

Sept façons à prendre en main la mise en œuvre de la formation médicale fondée sur les compétences au niveau des programmes

Competency-based medical education (CBME) curricula are becoming increasingly common in graduate medical education. Put simply, CBME is focused on educational outcomes, is independent of methods and time, and is composed of achievable competencies.1 In spite of widespread uptake, there remains much to learn about implementing CBME at the program level. Leveraging the collective experience of program leaders at Queen’s University, where CBME simultaneously launched across 29 specialty programs in 2017, this paper leverages change management theory to provide a short summary of how program leaders can navigate the successful preparation, launch, and initial implementation of CBME within their residency programs

The genetic architecture of the human cerebral cortex

The cerebral cortex underlies our complex cognitive capabilities, yet little is known about the specific genetic loci that influence human cortical structure. To identify genetic variants that affect cortical structure, we conducted a genome-wide association meta-analysis of brain magnetic resonance imaging data from 51,665 individuals. We analyzed the surface area and average thickness of the whole cortex and 34 regions with known functional specializations. We identified 199 significant loci and found significant enrichment for loci influencing total surface area within regulatory elements that are active during prenatal cortical development, supporting the radial unit hypothesis. Loci that affect regional surface area cluster near genes in Wnt signaling pathways, which influence progenitor expansion and areal identity. Variation in cortical structure is genetically correlated with cognitive function, Parkinson's disease, insomnia, depression, neuroticism, and attention deficit hyperactivity disorder

The genetic architecture of the human cerebral cortex

The cerebral cortex underlies our complex cognitive capabilities, yet little is known about the specific genetic loci that influence human cortical structure. To identify genetic variants that affect cortical structure, we conducted a genome-wide association meta-analysis of brain magnetic resonance imaging data from 51,665 individuals. We analyzed the surface area and average thickness of the whole cortex and 34 regions with known functional specializations. We identified 199 significant loci and found significant enrichment for loci influencing total surface area within regulatory elements that are active during prenatal cortical development, supporting the radial unit hypothesis. Loci that affect regional surface area cluster near genes in Wnt signaling pathways, which influence progenitor expansion and areal identity. Variation in cortical structure is genetically correlated with cognitive function, Parkinson's disease, insomnia, depression, neuroticism, and attention deficit hyperactivity disorder

Theoretical basis for Nursing

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