Collective Animal Behavior from Bayesian Estimation and Probability Matching

Animals living in groups make movement decisions that depend, among other factors, on social interactions with other group members. Our present understanding of social rules in animal collectives is based on empirical fits to observations and we lack first-principles approaches that allow their derivation. Here we show that patterns of collective decisions can be derived from the basic ability of animals to make probabilistic estimations in the presence of uncertainty. We build a decision-making model with two stages: Bayesian estimation and probabilistic matching.
In the first stage, each animal makes a Bayesian estimation of which behavior is best to perform taking into account personal information about the environment and social information collected by observing the behaviors of other animals. In the probability matching stage, each animal chooses a behavior with a probability given by the Bayesian estimation that this behavior is the most appropriate one. This model derives very simple rules of interaction in animal collectives that depend only on two types of reliability parameters, one that each animal assigns to the other animals and another given by the quality of the non-social information. We test our model by obtaining theoretically a rich set of observed collective patterns of decisions in three-spined sticklebacks, Gasterosteus aculeatus, a shoaling fish species. The quantitative link shown between probabilistic estimation and collective rules of behavior allows a better contact with other fields such as foraging, mate selection, neurobiology and psychology, and gives predictions for experiments directly testing the relationship between estimation and collective behavior

Montana v. Wyoming: Sprinklers, Irrigation Water Use Efficiency and the Doctrine of Recapture

In 2007, Montana filed an original action with the United States Supreme Court asserting that certain water uses in Wyoming violated the Yellowstone River Compact (“Compact”). The litigation was triggered by severe drought in the basin between 2000 and 2006, during which period there was inadequate water available for Montana appropriators in the Tongue River and Powder River sub-basins. Montana raised four primary issues: irrigation of new acreage in Wyoming; new and expanded storage facilities; new groundwater pumping, especially associated with coalbed methane development; and increased consumption of water due to improved irrigation efficiency on existing irrigated acreage. In 2011, the U.S. Supreme Court decided the first substantive issue in this litigation: “Is a switch to more efficient irrigation with less return flow within the extent of Wyoming’s pre-1950 users’ existing appropriative rights, or is it an improper enlargement of that right to the detriment of Montana’s pre-1950 water users?” The Court held that such improvements are permitted under the Compact. This Article takes a careful look at this decision. It begins with an introduction to the physical setting, focusing on the Tongue and Powder sub-basins within the Yellowstone basin. It discusses Montana’s arguments why the Compact precludes improved irrigation efficiency that increases consumption and the Special Master’s rejection of those arguments. Next, the Article looks at the U.S. Supreme Court’s opinion. Finally, it offers some observations triggered by this litigation, critiques the doctrine of recapture in western water law, and supports the Court’s embrace of water use efficiency over protection of the status quo. We begin with a look at the Yellowstone River basin

Knowledge brokering: Exploring the process of transferring knowledge into action

There are many theories about knowledge transfer but there are few clear descriptions of knowledge transfer interventions or the processes they involve. This failure to characterise structure and process in proposed KT interventions is a major barrier to the design and implementation of evaluations of particular KT strategies. This study is designed to provide a detailed description of the processes involved in a knowledge transfer intervention and to develop and refine a useful model of the knowledge transfer process

Consistency of Leadership in Shoals of Mosquitofish (Gambusia holbrooki) in Novel and in Familiar Environments

In social animal groups, an individual's spatial position is a major determinant of both predation risk and foraging rewards. Additionally, the occupation of positions in the front of moving groups is generally assumed to correlate with the initiation of group movements. However, whether some individuals are predisposed to consistently occupy certain positions and, in some instances, to consistently lead groups over time is as yet unresolved in many species. Using the mosquitofish (Gambusia holbrooki), we examined the consistency of individuals' spatial positions within a moving group over successive trials. We found that certain individuals consistently occupied front positions in moving groups and also that it was typically these individuals that initiated group decisions. The number of individuals involved in leading the group varied according to the amount of information held by group members, with a greater number of changes in leadership in a novel compared to a relatively familiar environment. Finally, our results show that the occupation of lead positions in moving groups was not explained by characteristics such as dominance, size or sex, suggesting that certain individuals are predisposed to leadership roles. This suggests that being a leader or a follower may to some extent be an intrinsic property of the individual

Understanding factors associated with the translation of cardiovascular research: A multinational case study approach

This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited.This article has been made available through the Brunel Open Access Publishing Fund.Background: Funders of health research increasingly seek to understand how best to allocate resources in order to achieve maximum value from their funding. We built an international consortium and developed a multinational case study approach to assess benefits arising from health research. We used that to facilitate analysis of factors in the production of research that might be associated with translating research findings into wider impacts, and the complexities involved. Methods: We built on the Payback Framework and expanded its application through conducting co-ordinated case studies on the payback from cardiovascular and stroke research in Australia, Canada and the United Kingdom. We selected a stratified random sample of projects from leading medical research funders. We devised a series of innovative steps to: minimize the effect of researcher bias; rate the level of impacts identified in the case studies; and interrogate case study narratives to identify factors that correlated with achieving high or low levels of impact. Results: Twenty-nine detailed case studies produced many and diverse impacts. Over the 15 to 20 years examined, basic biomedical research has a greater impact than clinical research in terms of academic impacts such as knowledge production and research capacity building. Clinical research has greater levels of wider impact on health policies, practice, and generating health gains. There was no correlation between knowledge production and wider impacts. We identified various factors associated with high impact. Interaction between researchers and practitioners and the public is associated with achieving high academic impact and translation into wider impacts, as is basic research conducted with a clinical focus. Strategic thinking by clinical researchers, in terms of thinking through pathways by which research could potentially be translated into practice, is associated with high wider impact. Finally, we identified the complexity of factors behind research translation that can arise in a single case. Conclusions: We can systematically assess research impacts and use the findings to promote translation. Research funders can justify funding research of diverse types, but they should not assume academic impacts are proxies for wider impacts. They should encourage researchers to consider pathways towards impact and engage potential research users in research processes. © 2014 Wooding et al.; licensee BioMed Central Ltd.RAND Europe and HERG, with subsequent funding from the NHFA, the HSFC and the CIHR. This research was also partially supported by the Policy Research Programme in the English Department of Health

Translating three states of knowledge--discovery, invention, and innovation

<p>Abstract</p> <p>Background</p> <p>Knowledge Translation (KT) has historically focused on the proper use of knowledge in healthcare delivery. A knowledge base has been created through empirical research and resides in scholarly literature. Some knowledge is amenable to direct application by stakeholders who are engaged during or after the research process, as shown by the Knowledge to Action (KTA) model. Other knowledge requires multiple transformations before achieving utility for end users. For example, conceptual knowledge generated through science or engineering may become embodied as a technology-based invention through development methods. The invention may then be integrated within an innovative device or service through production methods. To what extent is KT relevant to these transformations? How might the KTA model accommodate these additional development and production activities while preserving the KT concepts?</p> <p>Discussion</p> <p>Stakeholders adopt and use knowledge that has perceived utility, such as a solution to a problem. Achieving a technology-based solution involves three methods that generate knowledge in three states, analogous to the three classic states of matter. Research activity generates discoveries that are intangible and highly malleable like a gas; development activity transforms discoveries into inventions that are moderately tangible yet still malleable like a liquid; and production activity transforms inventions into innovations that are tangible and immutable like a solid. The paper demonstrates how the KTA model can accommodate all three types of activity and address all three states of knowledge. Linking the three activities in one model also illustrates the importance of engaging the relevant stakeholders prior to initiating any knowledge-related activities.</p> <p>Summary</p> <p>Science and engineering focused on technology-based devices or services change the state of knowledge through three successive activities. Achieving knowledge implementation requires methods that accommodate these three activities and knowledge states. Accomplishing beneficial societal impacts from technology-based knowledge involves the successful progression through all three activities, and the effective communication of each successive knowledge state to the relevant stakeholders. The KTA model appears suitable for structuring and linking these processes.</p

Maternal and perinatal guideline development in hospitals in South East Asia: the experience of the SEA-ORCHID project

<p>Abstract</p> <p>Background</p> <p>Clinical practice guidelines (CPGs) are commonly used to support practitioners to improve practice. However many studies have raised concerns about guideline quality. The reasons why guidelines are not developed following the established development methods are not clear.</p> <p>The SEA-ORCHID project aims to increase the generation and use of locally relevant research and improve clinical practice in maternal and perinatal care in four countries in South East Asia. Baseline data highlighted that development of evidence-based CPGs according to recommended processes was very rare in the SEA-ORCHID hospitals. The project investigators suggested that there were aspects of the recommended development process that made it very difficult in the participating hospitals.</p> <p>We therefore aimed to explore the experience of guideline development and particularly the enablers of and barriers to developing evidence-based guidelines in the nine hospitals in South East Asia participating in the SEA-ORCHID project, so as to better understand how evidence-based guideline development could be facilitated in these settings.</p> <p>Methods</p> <p>Semi-structured, face-to-face interviews were undertaken with senior and junior healthcare providers (nurses, midwives, doctors) from the maternal and neonatal services at each of the nine participating hospitals. Interviews were audio-recorded, transcribed and a thematic analysis undertaken.</p> <p>Results</p> <p>Seventy-five individual, 25 pair and eleven group interviews were conducted. Participants clearly valued evidence-based guidelines. However they also identified several major barriers to guideline development including time, lack of awareness of process, difficulties searching for evidence and arranging guideline development group meetings, issues with achieving multi-disciplinarity and consumer involvement. They also highlighted the central importance of keeping guidelines up-to-date.</p> <p>Conclusion</p> <p>Healthcare providers in the SEA-ORCHID hospitals face a series of barriers to developing evidence-based guidelines. At present, in many hospitals, several of these barriers are insurmountable, and as a result, rigorous, evidence-based guidelines are not being developed. Given the acknowledged benefits of evidence-based guidelines, perhaps a new approach to supporting their development in these contexts is needed.</p

Swarm Intelligence in Animal Groups: When Can a Collective Out-Perform an Expert?

An important potential advantage of group-living that has been mostly neglected by life scientists is that individuals in animal groups may cope more effectively with unfamiliar situations. Social interaction can provide a solution to a cognitive problem that is not available to single individuals via two potential mechanisms: (i) individuals can aggregate information, thus augmenting their ‘collective cognition’, or (ii) interaction with conspecifics can allow individuals to follow specific ‘leaders’, those experts with information particularly relevant to the decision at hand. However, a-priori, theory-based expectations about which of these decision rules should be preferred are lacking. Using a set of simple models, we present theoretical conditions (involving group size, and diversity of individual information) under which groups should aggregate information, or follow an expert, when faced with a binary choice. We found that, in single-shot decisions, experts are almost always more accurate than the collective across a range of conditions. However, for repeated decisions – where individuals are able to consider the success of previous decision outcomes – the collective's aggregated information is almost always superior. The results improve our understanding of how social animals may process information and make decisions when accuracy is a key component of individual fitness, and provide a solid theoretical framework for future experimental tests where group size, diversity of individual information, and the repeatability of decisions can be measured and manipulated

Small but crucial : the novel small heat shock protein Hsp21 mediates stress adaptation and virulence in Candida albicans

Peer reviewedPublisher PD

Initiative, Personality and Leadership in Pairs of Foraging Fish

Studies of coordinated movement have found that, in many animal species, bolder individuals are more likely to initiate movement and shyer individuals to follow. Here, we show that in pairs of foraging stickleback fish, leadership is not merely a passive consequence of temperamental differences. Instead, the act of initiating a joint foraging trip out of cover itself brings about a change in the role that an individual plays throughout the subsequent trip, and success in recruiting a partner affects an individual's tendency to initiate the next trip. On each joint trip, whichever fish took the initiative in leading out of cover gains greater influence over its partner's behaviour, which persists even after several changes in position (i.e. termination attempts and re-joining). During any given trip, the initiator is less responsive to its partner's movements than during trips initiated by the partner. An individual's personality had an important effect on its response to failure to recruit a partner: while bold fish were unaffected by failures to initiate a joint trip, shy individuals were less likely to attempt another initiation after a failure. This difference provides a positive feedback mechanism that can partially stabilise social roles within the pair, but it is not strong enough to prevent occasional swaps, with individuals dynamically adjusting their responses to one another as they exchange roles