The effect of local ventilation on airborne viral transmission in indoor spaces

We incorporate local ventilation effects into a spatially dependent generalisation of the Wells--Riley model of airborne viral transmission. Aerosol production and removal through ventilation (global and local), biological deactivation, and gravitational settling as well as transport around a recirculating air-conditioning flow and turbulent mixing are modelled using an advection--diffusion--reaction equation. The local ventilation effects are compared with the equivalent global ventilation and we find that the streamlines of the airflow provide insight into when the global ventilation model is a good approximation. When the agreement between ventilation models is poor, we find that the global ventilation model generally overestimates the infection risk.Comment: 10 pages, 4 figures, submitted to the Journal of Fluid Mechanics as a Rapids articl

BIBFRAME Readiness: A Canadian Perspective

In 2018 the University of Alberta Library (UAL) joined the LD4P2 Cohort as a part of a wider strategy for linked data and BIBFRAME implementation. During the same year the Canadian BIBFRAME Readiness Task Force (CBRTF) was formed to produce documentation that outlines the impact of migrating from MARC to BIBFRAME on libraries in Canada; to assess the understanding of and readiness for BIBFRAME transition in libraries in Canada; and to make recommendations for how the Canadian Federation of Library Associations / Fédération canadienne des associations de bibliothèques (CFLA-FCAB), Fédération des milieux documentaires (FMD), and Library and Archives Canada can support Canadian libraries’ transition to BIBFRAME. In this session, UAL’s experience and successes working towards BIBFRAME implementation will be juxtaposed to the findings of the CBRTF survey that few libraries in Canada are fully prepared to transition from MARC to BIBFRAME in the near future. Through this juxtaposition we will examine the current state of BIBFRAME readiness in Canada and outline CBRTF recommendations for a shared path forward

Needs in service provision for oral health care in older people. A comparison between Greater Manchester (UK) and Utrecht (The Netherlands).

Retaining natural teeth for longer, together with increasing care dependency in the elderly, has the potential to hamper adequate oral self-care and service provision. The aim of this qualitative study was to compare and contrast views from a multistakeholder perspective on the future priorities for oral health care services of older people in the United Kingdom and the Netherlands. A participatory setting partnership was undertaken with 4 key stakeholder groups in the United Kingdom and the Netherlands. A final consensus group considered collective responses. The views of the different groups were recorded, transcribed verbatim, and analyzed thematically. Two main themes derived: “individual well-being” and “underlying principles of service provision.” Codes relating to principles of service provision focused on the importance of developing quality criteria, improving access, prevention and screening, awareness raising, education and training, together with multidisciplinary care. In both countries, oral health was seen as an important element of “individual well-being,” and a number of “principles of service provision” were suggested. This contrasts with the current lack of evidence-based treatments and quality criteria that are available for dependent older people

The future of the global food system

Although food prices in major world markets are at or near a historical low, there is increasing concern about food security—the ability of the world to provide healthy and environmentally sustainable diets for all its peoples. This article is an introduction to a collection of reviews whose authors were asked to explore the major drivers affecting the food system between now and 2050. A first set of papers explores the main factors affecting the demand for food (population growth, changes in consumption patterns, the effects on the food system of urbanization and the importance of understanding income distributions) with a second examining trends in future food supply (crops, livestock, fisheries and aquaculture, and ‘wild food’). A third set explores exogenous factors affecting the food system (climate change, competition for water, energy and land, and how agriculture depends on and provides ecosystem services), while the final set explores cross-cutting themes (food system economics, food wastage and links with health). Two of the clearest conclusions that emerge from the collected papers are that major advances in sustainable food production and availability can be achieved with the concerted application of current technologies (given sufficient political will), and the importance of investing in research sooner rather than later to enable the food system to cope with both known and unknown challenges in the coming decades

Challenges to Community?Based Sustainable Development: Dynamics, Entitlements, Institutions

Summary Recent approaches to community?based natural resource management frequently present ‘communities’ as consensual units, able to act collectively in restoring population?resource imbalances or reestablishing harmonious relations between local livelihoods and stable environments. Arguing that these underlying assumptions and policy narratives are flawed as guidelines for policy, this article presents an alternative perspective which starts from the politics of resource access and control among diverse social actors, and sees patterns of environmental change as the outcomes of negotiation or contestation between their conflicting perspectives. The notion of ‘environmental entitlements’ encapsulates this shift in perspective, and provides analytical tools to specify the benefits that people gain from die environment which contribute to their well?being. The processes by which people gain environmental endowments and entitlements are, in turn, shaped by diverse institutions, both formal and informal

Toothpaste Prevents Debonded Brackets on Erosive Enamel

This study evaluated the effect of high fluoride dentifrice on the bond strength of brackets after erosive challenge. Eighty-four enamel specimens were divided into seven groups (n=12): WN (distilled water/no acid challenge), W3C (distilled water/3 cycles of acid challenge), and W6C (distilled water/6 cycles of acid challenge) were not submitted to dentifrice treatment. Groups RF3C (regular fluoride dentifrice/3 cycles of acid challenge) and RF6C (regular fluoride dentifrice/6 cycles of acid challenge) were treated with dentifrices containing 1450 μg F−/g and HF3C (high fluoride dentifrice/3 cycles of acid challenge) and HF6C (high fluoride dentifrice/6 cycles of acid challenge) were with 5000 μg F−/g. Acid challenges were performed for seven days. After bond strength test, there was no significant difference among groups submitted to 3 cycles of acid challenge (P>0.05). Statistically significant difference was found between the regular and high fluoride dentifrices after 6 cycles of acid challenge (<0.05). Similar areas of adhesive remaining were found among control groups and among groups W6C, RF3C, RF6C, HF3C, and HF6C. The high fluoride dentifrice was able to prevent the reduction of bond strength values of brackets submitted to acid challenge. Clinical relevance: the high fluoride toothpaste prevents debonded brackets on erosive enamel

Sustainable intensification – “oxymoron” or “third-way”? A systematic review

Sustainable Intensification (SI) is a term that has been advanced to capture a concept that some consider as the ‘third paradigm’ for global agricultural development. However, the term has become subject to intense debates as well as scepticism and confusion regarding its meaning and the characteristics of production systems that could indicate SI (defined as “indicators”). This has resulted in a proliferation of literature. We have conducted a systematic review of a sample of this literature analysing the most commonly suggested indicators of SI in order to investigate the extent to which the critiques of SI are valid in their viewpoints that SI is an oxymoron, underpinned by a productivist agenda, and to identify the critical issues in the development of a comprehensive and unambiguous set of SI indicators. From 633 articles identified by a search of relevant databases, a sample of 75 articles were selected and analysed using the NVIVO™ software. The results were organised according to a Socio-Ecological Systems (SES) framework comprising seven sub-systems or components − resource system, resource units, governance system, resource users, interactions, outcomes, and environment. A total of 218 indicators (both positive and negative) were identified. Most of these indicators focused on the ‘outcomes’ of agricultural systems with the majority being related to agricultural production. Few indicators were identified as relating to the economic and societal dimensions of food systems. Whilst this potentially suggested a productivist bias in the current interpretation of SI it was difficult to draw a black and white conclusion, since for the other system components, the majority of the indicators suggested appeared to take a more holistic point-of-view and emphasised both productivity and sustainability of agricultural systems. Our analysis suggests that a key reason why SI may be viewed with scepticism is a lack of specificity and elucidation of the rationale, scale, and farm type for which SI is proposed. Moreover, a number of the indicators were so loosely defined that the interventions they imply could be enacted without due consideration of the social impacts of their adoption. We conclude that there is need to develop SI indicators according to specific farming types and scales and also with more consideration of the social and political dimensions of food systems in order to promote a constructive dialogue around the concept of SI to take place. Unless the concept of SI is described and measured in such a holistic and inclusive manner, it is unlikely to be accepted as a valid descriptor of sought-after agricultural practices by players in the Third Sector

The Politics of Seed in Africa's Green Revolution: Alternative Narratives and Competing Pathways

As calls for a ‘Uniquely African Green Revolution’ gain momentum, a focus on seeds and seed systems is rising up the agricultural policy agenda. Much of the debate stresses the technological or market dimensions, with substantial investments being made in seed improvement and the development of both public and private sector delivery systems. But this misses out the political economy of policy processes behind this agenda: who wins, who loses, and whose interests are being served? Drawing on lessons from country case studies from Ethiopia, Ghana, Kenya, Malawi and Zimbabwe, as well as insights from a set of complementary studies of cross?cutting themes, this article assesses the evolution of seed system research and development programmes and processes across the region. By examining how the contrasting politics and different configurations of interests affect the way cereal seed systems operate, it highlights opportunities for reshaping the terms of the debate and opening up alternative pathways to more sustainable and socially just seed systems

Designing an environmental flow framework for impounded river systems through modelling of invertebrate habitat quality

Many rivers have undergone flow modification by impoundments to provide services such as water supply and hydropower. There is an established consensus that typical modified flow regimes do not sufficiently cater to the needs of downstream ecosystems, and more must be done to understand and mitigate their associated impacts. This study presents a novel, transferable framework by which a small-scale impoundment in North West England is assessed through the use of linked hydro-ecological modelling in SRH-2D and CASiMiR, utilising flow velocity measurements and macroinvertebrate sampling data. Model predictions of habitat quality were supplemented by established ecological principles such as the importance of flow heterogeneity. Results are used to design environmental flow regimes, with the aim of improving ecological metrics whilst considering conflicting water demands. Based on an analysis of historical flow records, the implementation of designer flows over a 12 month period demonstrated increased peak species habitat qualities of 23–26%, characteristics such as flow heterogeneity were more naturalised, and 22% less water was released from the impoundment. Should outcomes be validated by in-stream flow experiment, there is great potential for further development and application of this method, including regional transferability for the rapid designation of environmental flows across a number of sites of similar magnitude and geography