Objective functions with redundant domains

Let (E,A) be a set system consisting of a finite collection A of subsets of a ground set E, and suppose that we have a function ϕ which maps A into some set S. Now removing a subset K from E gives a restriction A(K¯) to those sets of A disjoint from K, and we have a corresponding restriction ϕ|A(K¯) of our function ϕ. If the removal of K does not affect the image set of ϕ, that is Im(ϕ|A(X¯))=Im(ϕ), then we will say that K is a kernel set of A with respect to ϕ. Such sets are potentially useful in optimisation problems defined in terms of ϕ. We will call the set of all subsets of E that are kernel sets with respect to ϕ a kernel system and denote it by Kerϕ(A). Motivated by the optimisation theme, we ask which kernel systems are matroids. For instance, if A is the collection of forests in a graph G with coloured edges and ϕ counts how many edges of each colour occurs in a forest then Kerϕ(A) is isomorphic to the disjoint sum of the cocycle matroids of the differently coloured subgraphs; on the other hand, if A is the power set of a set of positive integers, and ϕ is the function which takes the values 1 and 0 on subsets according to whether they are sum-free or not, then we show that Kerϕ(A) is essentially never a matroid

Charting equity in higher education: drawing the global access map

We know the economic benefit to individuals and to communities of increased levels of Higher Education (HE) participation. We also know that participation in HE has been expanding steadily; we anticipate there will be half a billion students participating in postsecondary education by 2030. But what do existing data tell us about who is accessing HE, and who is currently missing out? Specifically, what do we know about equity in access to high quality HE? Knowing that we are best able to manage what we measure, are institutions, nations, and international organisations capturing HE access data by critical social indicators (such as SES, gender, disability, or geographic remoteness to name but a few)

What should an index of school segregation measure?

The article aims to make a methodological contribution to the education segregation literature, providing a critique of previous measures of segregation used in the literature, as well as suggesting an alternative approach to measuring segregation. Specifically, the paper examines Gorard, Fitz and Taylor's finding that social segregation between schools, as measured by free school meals (FSM) entitlement, fell significantly in the years following the 1988 Education Reform Act. Using Annual Schools Census data from 1989 to 2004, the paper challenges the magnitude of their findings, suggesting that the method used by Gorard et al. seriously overstates the size of the fall in segregation. We make the case for a segregation curve approach to measuring segregation, where comparisons of the level of segregation are possible regardless of the percentage FSM eligibility. Using this approach, we develop a new method for describing both the level and the location of school segregation

The impact of a pharmacist on post-take ward round prescribing and medication appropriateness

Background Medication communication and prescribing on the post-take ward round following patient admission to hospital can be suboptimal leading to worse patient outcomes. Objective To evaluate the impact of clinical pharmacist participation on the post-take ward round on the appropriateness of medication prescribing, medication communication, and overall patient health care outcomes. Setting Tertiary referral teaching hospital, Brisbane, Australia. Method A pre-post intervention study was undertaken that compared the addition of a senior clinical pharmacist attending the post-take ward was compared to usual wardbase pharmacist service, with no pharmacist present of the post-take ward round. We assessed the proportion of patients with an improvement in medication appropriateness from admission to discharge, using the START/STOPP checklists. Medication communication was assessed by the mean number of brief and in-depth discussions, with health care outcomes measured by comparing length of stay and 28-day readmission rates. Main outcome measures: Medication appropriateness according to the START/STOPP list, number and type of discussions with team members and length of stay and readmission rate. Results Two hundred and sixty patients were recruited (130 pre- and 130-post-intervention), across 23 and 20 post-take ward rounds, respectively. Post-intervention, there was increase in the proportion of patients who had an improvement medication appropriateness (pre-intervention 25.4%, post-intervention 36.9%; p = 0.004), the number of in-depth discussions about patients’ medication (1.9 ± 1.7 per patient pre-intervention, 2.7 ± 1.7 per patient post-, p < 0.001), and the number relating to high-risk medications (0.71 ± 1.1 per patient pre-intervention, to 1.2 ± 1.2 per patient post-, p < 0.05). Length of stay and 28-day mortality were unchanged. Conclusion Clinical pharmacist participation on the post-take ward round leads to improved medication-related communication and improved medication appropriateness but did not significantly improve health care outcomes

Inter-decadal variation in diadromous and potamodromous fish assemblages in a near pristine tropical dryland river

Freshwater ecosystems are both incredibly biodiverse and highly threatened globally. Variation in environmental parameters including habitat and flow can substantially affect many ecological processes within riverine aquatic communities, but the ties between such parameters and ecology are neither well studied nor understood. In highly variable tropical dryland river systems, assessing such relationships requires data collection over inter-decadal time scales, which is not typically permitted on development schedules driven over short periods (including election and funding cycles). Here, we used seine net sampling data collected over an 18-year period in the tropical dryland Fitzroy River, Western Australia, to assess how environmental and temporal factors including habitat, seasonality, and inter-annual variation in wet season magnitude affect the community assemblage structure, recruitment, and growth of aquatic species in dryland rivers. Results demonstrated that macrohabitat (main channel vs floodplain creek) and the magnitude of wet season rains and resultant flooding both had a substantial influence on biotic communities, alongside seasonal and diel variation. The magnitude of wet season flooding (measured as river discharge volume) had the greatest impact on assemblage composition within floodplain creek habitats and was a significant driver of recruitment rates and growth of recruits and adults of several species examined. This study highlights key considerations for conserving dryland river systems and constituent biota. Specifically, these are maintaining (a) rhythmicity of flow within each year, (b) diversity of flow volume between years, and (c) a variety of habitat types including ephemeral, semi-permanent, and permanent shallow floodplain and deeper main channel pools, in order to support a diverse array of generalist and specialist diadromous and potamodromous fishes

Economic evaluation strategies in telehealth: obtaining a more holistic valuation of telehealth interventions

Telehealth is an emerging area of medical research. Its translation from conception, to research and into practice requires tailored research and economic evaluation methods. Due to their nature telehealth interventions exhibit a number of extra-clinical benefits that are relevant when valuing their costs and outcomes. By incorporating methods to measure societal values such as patient preference and willingness-to-pay, a more holistic value can be placed on the extra-clinical outcomes associated with telehealth and evaluations can represent new interventions more effectively. Cost-benefit analysis is a method by which relevant costs and outcomes in telehealth can be succinctly valued and compared. When health economic methods are conducted using holistic approaches such as cost-benefit analysis they can facilitate the translation of telehealth research into policy and practice

A telegeriatric service in a small rural hospital: A case study and cost analysis

Introduction Small hospitals in rural areas usually have an insufficient caseload of frail old people to justify the regular presence of a geriatrician. This study examined the costs of providing a telegeriatric service by videoconference in a rural hospital, compared to the costs of a visiting geriatrician that travels to undertake in-person consultations. Methods A cost analysis was undertaken to compare the costs of the telegeriatric service model with the costs of a visiting geriatrician service model. A recently established telegeriatric service at Warwick Hospital was used as a case study. Results In the base case model (assuming four patients per round and a round-trip travel distance of 312 kilometres), an estimated AUD$131 per patient consultation can be saved in favour of the telegeriatric service model. Key drivers of costs are the number of patients per round and the travel distance and time in the visiting geriatrician model. At a workload of four patients per round, it is less expensive to conduct a telegeriatric service than a visiting geriatrician service when the round-trip travel time exceeds 76 minutes. Discussion Even under quite conservative assumptions, a telegeriatric service offers an economically feasible approach to the delivery of specialist geriatric assessment in rural and remote settings

Diversity and complexity: becoming a teacher in England in 2015-16

This paper is based on a profile of Initial Teacher Training (ITT) provision in England, which was developed as part of a wider research programme on Diversity in Teacher Education (DiTE) based at Bath Spa University (Whiting et al, 2016). It provides a new topography of routes to qualified teacher status (QTS) in England for the academic year 2015-16, along similar lines to an exercise undertaken for an earlier research programme, the ESRC funded Modes of Teacher Education (MOTE) projects conducted in the 1990s (Barrett et al, 1992; Whiting et al, 1996; Furlong et al, 2000). The allocations and census data published by the National College for Teaching and Leadership (NCTL) provide the basis for this new topography, with additional material from a range of sources, mostly online. Reflections on further changes in policy discourse since the year of analysis hint at an acknowledgement of the role of Higher Education (HE) and a reduced emphasis on the much vaunted focus on ‘school-led’ routes. However, there is little to reassure either ITT providers, or potential candidates, of a long term plan aimed at halting the trajectory towards over-complexity and incoherence. The analysis raises important questions about the quality of such diverse teacher education provision, the nature of partnership between higher education institutions and schools, and the impact of reform on the identities of those training to teach