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Herbicide resistance has been studied extensively in agronomic crops across North America but is rarely examined in vegetables. It is widely assumed that the limited number of registered herbicides combined with the adoption of diverse weed management strategies in most vegetable crops effectively inhibits the development of resistance. It is difficult to determine whether resistance is truly less common in vegetable crops or whether the lack of reported cases is due to the lack of resources focused on detection. This review highlights incidences of resistance that are thought to have arisen within vegetable crops. It also includes situations in which herbicide-resistant weeds were likely selected for within agronomic crops but became a problem when vegetables were grown in sequence or in adjacent fields. Occurrence of herbicide resistance can have severe consequences for vegetable growers, and resistance management plans should be adopted to limit selection pressure. This review also highlights resistance management techniques that should slow the development and spread of herbicide resistance in vegetable crops. Published version

Human residential population distributions show patterns of higher density clustering around local services such as shops and places of employment, displaying characteristic length scales; Fourier transforms and spatial autocorrelation show the length scale between UK cities is around 45 km. We use integro-differential equations to model the spatio-temporal dynamics of population and service density under the assumption that they benefit from spatial proximity, captured via spatial weight kernels. The system tends towards a well mixed homogeneous state or a spatial pattern. Linear stability analysis around the homogeneous steady state predicts a modelled length scale consistent with that observed in the data. Moreover, we show that spatial instability occurs only for perturbations with a sufficiently long wavelength and only where there is a sufficiently strong dependence of service potential on population density. Within urban centres, competition for space may cause services and population to be out of phase with one another, occupying separate parcels of land. By introducing competition, along with a preference for population to be located near, but not too near, to high service density areas, secondary out-of-phase patterns occur within the model, at a higher density and with a shorter length scale than in phase patterning. Thus, we show that a small set of core behavioural ingredients can generate aggregations of populations and services, and pattern formation within cities, with length scales consistent with real-world data. The analysis and results are valid across a wide range of parameter values and functional forms in the model.

Older adults are more thermally vulnerable than the younger adults that comfort metrics tend to be empirically drawn from. They are less able to discriminate between warmth and cold and those that experience motor or neurological impairments may be less able to perceive or communicate their thermal sensation and preference; placing the onus of thermal regulation on their carers. This situation is accentuated as societies age, so that there is a growing need for guidance for the thermal regulation of care homes; to establish whether existing metrics may be used with confidence or whether the evidence base needs to be extended to encompass data from older adults. To this end, this paper presents a study of three approaches to thermal comfort modelling for older age care home residents: (1) Predicted Mean Vote (PMV), (2) Adaptive Comfort, and (3) long wave infrared thermography (IRT). Based on measurements from a previous field survey, our results show that (1) PMV can, in principle, be applicable to older people, but procedures for estimating metabolic rates are outmoded and summertime conditions tend to be free-running; (2) Adaptive Comfort appears to be well suited and can also consider feedback from adaptive actions; (3) The difference in skin temperature obtained from infrared maps of the upper extremities (hands, wrist, forearm) has potential as an indicator of thermal comfort, if these measurements can be practically deployed. However, all three approaches are limited in their ability to account for the distribution of thermal sensations collected from subjects with dementia.

The three-pillar conception of (social, economic and environmental) sustainability, commonly represented by three intersecting circles with overall sustainability at the centre, has become ubiquitous. With a view of identifying the genesis and theoretical foundations of this conception, this paper reviews and discusses relevant historical sustainability literature. From this we find that there is no single point of origin of this three-pillar conception, but rather a gradual emergence from various critiques in the early academic literature of the economic status quo from both social and ecological perspectives on the one hand, and the quest to reconcile economic growth as a solution to social and ecological problems on the part of the United Nations on the other. The popular three circles diagram appears to have been first presented by Barbier (Environ Conserv 14:101, doi: 10.1017/s0376892900011449, 1987), albeit purposed towards developing nations with foci which differ from modern interpretations. The conceptualisation of three pillars seems to predate this, however. Nowhere have we found a theoretically rigorous description of the three pillars. This is thought to be in part due to the nature of the sustainability discourse arising from broadly different schools of thought historically. The absence of such a theoretically solid conception frustrates approaches towards a theoretically rigorous operationalisation of ‘sustainability’.