Psychiatric illness predicts poor outcome after surgery for hip fracture: a prospective cohort study

Background. Hip fracture is common in the elderly. Previous studies suggest that psychiatric illness is common and predicts poor outcome, but have methodological weaknesses. Further studies are required to address this important issue. Methods. We prospectively recruited 731 elderly participants with hip fracture in two Leeds hospitals. Psychiatric diagnosis was made within 5 days of surgery using the Geriatric Mental State schedule and other standardized instruments, and data on confounding factors was collected. Main study outcomes were length of hospital stay, and mortality over 6 months after fracture. Results. Fifty-five per cent of participants had cognitive impairment (dementia in 40% and delirium in 15%), 13% had a depressive disorder, 2% had alcohol misuse and 2% had other psychiatric diagnoses. Participants were likely to remain in hospital longer if they suffered from dementia, delirium or depression. The relative risks of mortality over 6 months after hip fracture were increased in dementia and delirium, but not in depression. Conclusions. Psychiatric illness is common after hip fracture, and has significant effects on important outcomes. This suggests a need for randomized, controlled trials of psychiatric interventions in the elderly hip fracture population

Exact and approximate moment closures for non-Markovian network epidemics

Moment-closure techniques are commonly used to generate low-dimensional deterministic models to approximate the average dynamics of stochastic systems on networks. The quality of such closures is usually difficult to asses and the relationship between model assumptions and closure accuracy are often difficult, if not impossible, to quantify. Here we carefully examine some commonly used moment closures, in particular a new one based on the concept of maximum entropy, for approximating the spread of epidemics on networks by reconstructing the probability distributions over triplets based on those over pairs. We consider various models (SI, SIR, SEIR and Reed-Frost-type) under Markovian and non-Markovian assumption characterising the latent and infectious periods. We initially study two special networks, namely the open triplet and closed triangle, for which we can obtain analytical results. We then explore numerically the exactness of moment closures for a wide range of larger motifs, thus gaining understanding of the factors that introduce errors in the approximations, in particular the presence of a random duration of the infectious period and the presence of overlapping triangles in a network. We also derive a simpler and more intuitive proof than previously available concerning the known result that pair-based moment closure is exact for the Markovian SIR model on tree-like networks under pure initial conditions. We also extend such a result to all infectious models, Markovian and non-Markovian, in which susceptibles escape infection independently from each infected neighbour and for which infectives cannot regain susceptible status, provided the network is tree-like and initial conditions are pure. This works represent a valuable step in deepening understanding of the assumptions behind moment closure approximations and for putting them on a more rigorous mathematical footing.Comment: Main text (45 pages, 11 figures and 3 tables) + supplementary material (12 pages, 10 figures and 1 table). Accepted for publication in Journal of Theoretical Biology on 27th April 201

Victor Melgar's Coffee Farm

This case study focuses on a coffee farmer in Guatemala who, given current low coffee prices, is worried about his ability to maintain the family tradition of coffee production. He wonders whether the current low prices are just another of the periodic downturns in the volatile coffee market or whether the market is experiencing structural changes that will have long-term implications. In this case, the farmer is presented with three alternatives, including continuing to produce and market commodity coffee. The other alternatives involve changes in production and/or marketing practices intended to increase profit margins.Crop Production/Industries,

Patterns of Late Cenozoic exhumation deduced from apatite and zircon U-He ages from Fiordland, New Zealand

New apatite and zircon (U-Th)/He ages from the Fiordland region of New Zealand's South Island expand on earlier results and provide new constraints on patterns of Late Cenozoic exhumation and cooling across this region. Zircon (U-Th)/He cooling ages, in combination with increased density of apatite ages, show that in addition to a gradual northward decrease in cooling ages that was seen during an earlier phase of this study, there is also a trend toward younger cooling ages to the east. Distinct breaks in cooling age patterns on southwestern Fiordland appear to be correlated to the location of previously mapped faults. The northward decrease in ages may reflect asynchronous cooling related to migration in the locus of exhumation driven by subduction initiation, or it may reflect synchronous regional exhumation that exposed different structural levels across Fiordland, or some combination of these effects. In either case, differential exhumation accommodated by major and minor faults that dissect Fiordland basement rocks apparently played an important role in producing the resulting age patterns

Consumer acceptance of insect-based foods in the Netherlands: Academic and commercial implications.

Despite growing interest in the use of insects as food, uptake of insect-based foods in Europe is low. Existing research into Western consumer acceptance of insects as food tends to emphasise the role of individual cognition in food choice at the expense of social or contextual factors, and typically frames consumer acceptance as a general issue, rather than relevant only for relatively few early adopters. This paper outlines empirical work, theoretically and methodologically informed by a critical appraisal of previous research, with consumers of insect-based convenience foods in the Netherlands. Reported initial motivations for trying insect foods are shown to be substantially different from factors - such as price, taste, availability, and 'fit' with established eating practices - which affect repeat consumption. Such factors are congruent with those affecting routine consumption of more conventional foods, indicating that insect foods should be analysed according to similar criteria and should be designed with more practical considerations in mind. Further, a reorientation of consumer acceptance research is proposed. Research should shift from attempts to forecast acceptance and engage with 'actual' examples of insect consumption; social, practical and contextual factors affecting food consumption should be emphasised; and - following work on the establishment of other novel foods - early adopters, rather than general populations, should receive greater analytic attention