Colour reverse learning and animal personalities: the advantage of behavioural diversity assessed with agent-based simulations

Foraging bees use colour cues to help identify rewarding from unrewarding flowers, but as conditions change, bees may require behavioural flexibility to reverse their learnt preferences. Perceptually similar colours are learnt slowly by honeybees and thus potentially pose a difficult task to reverse-learn. Free-flying honeybees (N = 32) were trained to learn a fine colour discrimination task that could be resolved at ca. 70% accuracy following extended differential conditioning, and were then tested for their ability to reverse-learn this visual problem multiple times. Subsequent analyses identified three different strategies: ‘Deliberative-decisive’ bees that could, after several flower visits, decisively make a large change to learnt preferences; ‘Fickle- circumspect’ bees that changed their preferences by a small amount every time they encountered evidence in their environment; and ‘Stay’ bees that did not change from their initially learnt preference. The next aim was to determine if there was any advantage to a colony in maintaining bees with a variety of decision-making strategies. To understand the potential benefits of the observed behavioural diversity agent-based computer simulations were conducted by systematically varying parameters for flower reward switch oscillation frequency, flower handling time, and fraction of defective ‘target’ stimuli. These simulations revealed that when there is a relatively high frequency of reward reversals, fickle-circumspect bees are more efficient at nectar collection. However, as the reward reversal frequency decreases the performance of deliberative-decisive bees becomes most efficient. These findings show there to be an evolutionary benefit for honeybee colonies with individuals exhibiting these different strategies for managing resource change. The strategies have similarities to some complex decision-making processes observed in humans, and algorithms implemented in artificial intelligence systems

Enhanced activation of an amino-terminally truncated isoform of the voltage-gated proton channel HVCN1 enriched in malignant B cells

The final published version can be found here: http://dx.doi.org/10.1073/pnas.1411390111M.C. is the recipient of a Bennett Fellowship from Leukaemia and Lymphoma Research (ref. 12002). M.A.B. is supported by a GlaxoSmithKline Oncology–Biotechnology and Biological Sciences Research Council Collaborative Awards in Science and Engineering PhD studentship. This work was supported by National Institutes of Health Grants GM087507 and GM102336 (to T.E.D.)

Visual search in ecological and non-ecological displays: Evidence for a non-monotonic effect of complexity on performance

Copyright @ 2013 PLoSThis article has been made available through the Brunel Open Access Publishing Fund.Considerable research has been carried out on visual search, with single or multiple targets. However, most studies have used artificial stimuli with low ecological validity. In addition, little is known about the effects of target complexity and expertise in visual search. Here, we investigate visual search in three conditions of complexity (detecting a king, detecting a check, and detecting a checkmate) with chess players of two levels of expertise (novices and club players). Results show that the influence of target complexity depends on level of structure of the visual display. Different functional relationships were found between artificial (random chess positions) and ecologically valid (game positions) stimuli: With artificial, but not with ecologically valid stimuli, a “pop out” effect was present when a target was visually more complex than distractors but could be captured by a memory chunk. This suggests that caution should be exercised when generalising from experiments using artificial stimuli with low ecological validity to real-life stimuli.This study is funded by Brunel University and the article is made available through the Brunel Open Access Publishing Fund

Dynamics of pedestrians in regions with no visibility - a lattice model without exclusion

We investigate the motion of pedestrians through obscure corridors where the lack of visibility (due to smoke, fog, darkness, etc.) hides the precise position of the exits. We focus our attention on a set of basic mechanisms, which we assume to be governing the dynamics at the individual level. Using a lattice model, we explore the effects of non-exclusion on the overall exit flux (evacuation rate). More precisely, we study the effect of the buddying threshold (of no-exclusion per site) on the dynamics of the crowd and investigate to which extent our model confirms the following pattern revealed by investigations on real emergencies: If the evacuees tend to cooperate and act altruistically, then their collective action tends to favor the occurrence of disasters.Comment: 20 page

How to engage public support to protect overlooked species

Treves et al. (2019) propose a non-anthropocentric approach to conservation biology for the ‘just preservation’ of non-humans. Some of our current ways of ranking conservation efforts based on benefits to humans are indeed critically flawed, but we doubt that a completely non-anthropocentric approach is possible at this time. We propose a way to generate public support for those non-human species that may otherwise be overlooked in policy-making and conservation efforts

The Role of Botanic Gardens in Species Recovery :: The Oblong Woodsia as a Case Study

A translocation experiment to reintroduce the rare fern Woodsia ilvensis (L.) R.Br. to former sites in England and Scotland is described. The demands of this kind of conservation work brings the work of scientists and horticulturists together. High losses of transplants are to be expected and in order to gradually build up populations in the wild, translocation programmes may have to adopt a multi-phased approach. The facilities at botanic gardens are well suited to this type of conservation work

A reappraisal of the freehold property market in late medieval England

This paper re-examines the late medieval market in freehold land, the extent to which it was governed by market forces as opposed to political or social constraints, and how this contributed to the commercialisation of the late medieval English economy. We employ a valuable new resource for study of this topic in the form of an extensive dataset on late medieval English freehold property transactions. Through analysis of this data, we examine how the level of market activity (the number of sales) and the nature of the properties (the relative proportions of different types of asset) varied across regions and over time. In particular, we consider the impact of exogenous factors and the effects of growing commercialisation. We argue that peaks of activity following periods of crisis (Great Famine and Black Death) indicate that property ownership became open to market speculation. In so doing, we present an important new perspective on the long-term evolution of the medieval English property market

Randomized controlled trial of a book-sharing intervention in a deprived South African community: effects on carer-infant interactions, and their relation to infant cognitive and socio-emotional outcome

Background: Consistent with evidence from high income countries, we previously showed that, in an informal peri-urban settlement in a low-middle income country, training parents in book-sharing with their infants benefitted infant language and attention (Vally et al., 2015). Here, we investigated whether these benefits were explained by improvements in carer-infant interactions in both book-sharing and non-book-sharing contexts. We also explored whether infant socio-emotional development benefitted from book-sharing. Methods: We conducted a randomized controlled trial in Khayelitsha, South Africa. Carers of 14-16 month-old infants were randomized to 8 weeks’ training in book-sharing (n = 49) or a wait list control group (n = 42). In addition to the cognitive measures reported previously, independent assessments were made at base line and follow-up of carer-infant interactions during book-sharing and toy play. Assessments were also made, at follow-up only, of infant pro-social behaviour in a ‘help task’, and of infant imitation of doll characters’ non-social actions and an interpersonal interaction. Eighty-two carer-infant pairs (90%) were assessed at follow-up. (Trial registration ISRCTN39953901). Results: Carers who received the training showed significant improvements in book-sharing interactions (sensitivity, elaborations, reciprocity), and, to a smaller extent, in toy-play interactions (sensitivity). Infants in the intervention group showed a significantly higher rate of pro-social behaviour, and tended to show more frequent imitation of the interpersonal interaction. Improvements in carer behaviour during book-sharing, but not during toy play, mediated intervention effects on all infant cognitive outcomes, and tended to mediate intervention effects on infant interpersonal imitation. Conclusions: Training in book sharing, a simple, inexpensive intervention that has been shown to benefit infant cognitive development in a low-middle income country, also shows promise for improving infant socio-emotional outcomes in this context. Benefits are mediated by improvements in carer-infant interactions, particularly in book-sharing contexts

A LinkedIn Analysis of Career Paths of Information Systems Alumni

Information harvested from the LinkedIn profiles for 175 graduates of an Information Systems program at a mid-sized comprehensive university in Southeastern USA are summarized in this investigation. The current investigation was undertaken to examine the extent to which LinkedIn profiles are able to provide a more realistic picture of entry-level jobs held by program alumni and subsequent career progress. In addition, our results suggest that LinkedIn profiles can help answer questions such as: “What jobs do IS graduates get?”, “What does the career of an IS professional typically look like?”, and “Whether IS graduates can successfully transition from technical to managerial positions?”. Our findings also suggest that information in LinkedIn profiles can be used to assess the long-term outcomes of IS programs