Attractor Metadynamics in Adapting Neural Networks

Slow adaption processes, like synaptic and intrinsic plasticity, abound in the brain and shape the landscape for the neural dynamics occurring on substantially faster timescales. At any given time the network is characterized by a set of internal parameters, which are adapting continuously, albeit slowly. This set of parameters defines the number and the location of the respective adiabatic attractors. The slow evolution of network parameters hence induces an evolving attractor landscape, a process which we term attractor metadynamics. We study the nature of the metadynamics of the attractor landscape for several continuous-time autonomous model networks. We find both first- and second-order changes in the location of adiabatic attractors and argue that the study of the continuously evolving attractor landscape constitutes a powerful tool for understanding the overall development of the neural dynamics

Maximising Social Interactions and Effectiveness within Distance Learning Courses: Cases from Construction

Advanced Internet technologies have revolutionised the delivery of distance learning education. As a result, the physical proximity between learners and the learning providers has become less important. However, whilst the pervasiveness of these technological developments has reached unprecedented levels, critics argue that the student learning experience is still not as effective as conventional face-to-face delivery. In this regard, surveys of distance learning courses reveal that there is often a lack of social interaction attributed to this method of delivery, which tends to leave learners feeling isolated due to a lack of engagement, direction, guidance and support by the tutor. This paper defines and conceptualises this phenomenon by investigating the extent to which distance-learning programmes provide the social interactions of an equivalent traditional classroom setting. In this respect, two distance learning case studies were investigated, covering the UK and Slovenian markets respectively. Research findings identified that delivery success is strongly dependent on the particular context to which the specific distance learning course is designed, structured and augmented. It is therefore recommended that designers of distance learning courses should balance the tensions and nuances associated with commercial viability and pedagogic effectiveness

Doing nothing? An ethnography of patients' (In)activity on an acute stroke unit.

Health research has begun to pay increasing attention to inactivity in its broadest sense as lack of meaningful activity and boredom. Few studies however have taken a critical look at this phenomenon. We explore (in)activity drawing on ethnographic data from observations in an acute stroke unit and post-discharge interviews with stroke survivors and their families. Four themes emerged that explain patients' (in)activity: (i) planned activities; (ii) 'doing nothing', (iii) the material environment of the unit; (iv) interactions with staff. Considering these themes, we seek to problematise received conceptual and methodological approaches to understanding (in)activity. We argue that (in)activity is best conceived not as lack of action or meaning, but as a situated practice encompassing both bodily and mental activities that reflect and reproduce the way in which life is collectively organised within a specific healthcare setting

Cerebral blood flow predicts differential neurotransmitter activity

Application of metabolic magnetic resonance imaging measures such as cerebral blood flow in translational medicine is limited by the unknown link of observed alterations to specific neurophysiological processes. In particular, the sensitivity of cerebral blood flow to activity changes in specific neurotransmitter systems remains unclear. We address this question by probing cerebral blood flow in healthy volunteers using seven established drugs with known dopaminergic, serotonergic, glutamatergic and GABAergic mechanisms of action. We use a novel framework aimed at disentangling the observed effects to contribution from underlying neurotransmitter systems. We find for all evaluated compounds a reliable spatial link of respective cerebral blood flow changes with underlying neurotransmitter receptor densities corresponding to their primary mechanisms of action. The strength of these associations with receptor density is mediated by respective drug affinities. These findings suggest that cerebral blood flow is a sensitive brain-wide in-vivo assay of metabolic demands across a variety of neurotransmitter systems in humans

Addressing inactivity after stroke: The Collaborative Rehabilitation in Acute Stroke (CREATE) study.

BACKGROUND: Stroke patients are often inactive outside of structured therapy sessions - an enduring international challenge despite large scale organizational changes, national guidelines and performance targets. We examined whether experienced-based co-design (EBCD) - an improvement methodology - could address inactivity in stroke units. AIMS: To evaluate the feasibility and impact of patients, carers, and staff co-designing and implementing improvements to increase supervised and independent therapeutic patient activity in stroke units and to compare use of full and accelerated EBCD cycles. METHODS: Mixed-methods case comparison in four stroke units in England. RESULTS: Interviews were held with 156 patients, staff, and carers in total; ethnographic observations for 364 hours, behavioral mapping of 68 patients, and self-report surveys from 179 patients, pre- and post-implementation of EBCD improvement cycles.Three priority areas emerged: (1) 'Space' (environment); (2) 'Activity opportunities' and (3) 'Communication'. More than 40 improvements were co-designed and implemented to address these priorities across participating units. Post-implementation interview and ethnographic observational data confirmed use of new social spaces and increased activity opportunities. However, staff interactions remained largely task-driven with limited focus on enabling patient activity. Behavioral mapping indicated some increases in social, cognitive, and physical activity post-implementation, but was variable across sites. Survey responses rates were low at 12-38% and inconclusive. CONCLUSION: It was feasible to implement EBCD in stroke units. This resulted in multiple improvements in stroke unit environments and increased activity opportunities but minimal change in recorded activity levels. There was no discernible difference in experience or outcome between full and accelerated EBCD; this methodology could be used across hospital stroke units to assist staff and other stakeholders to co-design and implement improvement plans

Addressing inactivity after stroke: The Collaborative Rehabilitation in Acute Stroke (CREATE) study.

BACKGROUND: Stroke patients are often inactive outside of structured therapy sessions - an enduring international challenge despite large scale organizational changes, national guidelines and performance targets. We examined whether experienced-based co-design (EBCD) - an improvement methodology - could address inactivity in stroke units. AIMS: To evaluate the feasibility and impact of patients, carers, and staff co-designing and implementing improvements to increase supervised and independent therapeutic patient activity in stroke units and to compare use of full and accelerated EBCD cycles. METHODS: Mixed-methods case comparison in four stroke units in England. RESULTS: Interviews were held with 156 patients, staff, and carers in total; ethnographic observations for 364 hours, behavioral mapping of 68 patients, and self-report surveys from 179 patients, pre- and post-implementation of EBCD improvement cycles.Three priority areas emerged: (1) 'Space' (environment); (2) 'Activity opportunities' and (3) 'Communication'. More than 40 improvements were co-designed and implemented to address these priorities across participating units. Post-implementation interview and ethnographic observational data confirmed use of new social spaces and increased activity opportunities. However, staff interactions remained largely task-driven with limited focus on enabling patient activity. Behavioral mapping indicated some increases in social, cognitive, and physical activity post-implementation, but was variable across sites. Survey responses rates were low at 12-38% and inconclusive. CONCLUSION: It was feasible to implement EBCD in stroke units. This resulted in multiple improvements in stroke unit environments and increased activity opportunities but minimal change in recorded activity levels. There was no discernible difference in experience or outcome between full and accelerated EBCD; this methodology could be used across hospital stroke units to assist staff and other stakeholders to co-design and implement improvement plans

Using co-production to increase activity in acute stroke units: the CREATE mixed-methods study

BackgroundStroke is the most common neurological disability in the UK. Any activity contributes to recovery, but stroke patients can be inactive for > 60% of their waking hours. This problem remains, despite organisational changes and targeted interventions. A new approach to addressing post-stroke inactivity is needed. Experience-based co-design has successfully initiated improvements for patients and staff in other acute settings. Experience-based co-design uses observational fieldwork and filmed narratives with patients to trigger different conversations and interactions between patients and staff to improve health-care services.ObjectivesTo complete a rapid evidence synthesis of the efficacy and effectiveness of co-production as an approach to quality improvement in acute health-care settings; to evaluate the feasibility and impact of patients, carers and staff co-producing and implementing interventions to increase supervised and independent therapeutic patient activity in acute stroke units; and to understand the experience of participating in experience-based co-design and whether or not interventions developed and implemented in two units could transfer to two additional units using an accelerated experience-based co-design cycle.DesignA mixed-methods case comparison using interviews, observations, behavioural mapping and self-report surveys (patient-reported outcome measure/patient-reported experience measure) pre and post implementation of experience-based co-design cycles, and a process evaluation informed by normalisation process theory.SettingThe setting was two stroke units (acute and rehabilitation) in London and two in Yorkshire.ParticipantsIn total, 130 staff, 76 stroke patients and 47 carers took part.FindingsThe rapid evidence synthesis showed a lack of rigorous evaluation of co-produced interventions in acute health care, and the need for a robust critique of co-production approaches. Interviews and observations (365 hours) identified that it was feasible to co-produce and implement interventions to increase activity in priority areas including ‘space’ (environment), ‘activity’ and, to a lesser extent, ‘communication’. Patients and families reported benefits from participating in co-design and perceived that they were equal and valued members. Staff perceived that experience-based co-design provided a positive experience, was a valuable improvement approach and led to increased activity opportunities. Observations and interviews confirmed the use of new social spaces and increased activity opportunities. However, staff interactions remained largely task focused, with limited focus on enabling patient activity. Behavioural mapping indicated a mixed pattern of activity pre and post implementation of co-designed changes. Patient-reported outcome measure/patient-reported experience measure response rates were low, at 12–38%; pre- and post-experience-based co-design cohorts reported dependency, emotional and social limitations consistent with national statistics. Post-experience-based co-design patient-reported experience measure data indicated that more respondents reported that they had ‘enough things to do in their free time’. The use of experience-based co-design – full and accelerated – legitimised and supported co-production activity. Staff, patients and families played a pivotal role in intervention co-design. All participants recognised that increased activity should be embedded in everyday routines and in work on stroke units.LimitationsCommunication by staff that enabled patient activity was challenging to initiate and sustain.ConclusionsIt was feasible to implement experience-based co-design in stroke units. This resulted in some positive changes in unit environments and increased activity opportunities for patients. There was no discernible difference in experiences or outcomes between full and accelerated experience-based co-design. Future work should consider multiple ways to embed increased patient activity into everyday routines in stroke units.FundingThis project was funded by the National Institute for Health Research (NIHR) Health Services and Delivery Research programme and will be published in full in Health Services and Delivery Research; Vol. 8, No. 35. See the NIHR Journals Library website for further project information

Co-designing organisational improvements and interventions to increase inpatient activity in four stroke units in England: a mixed-methods process evaluation using normalisation process theory.

OBJECTIVE: To explore facilitators and barriers to using experience-based co-design (EBCD) and accelerated EBCD (AEBCD) in the development and implementation of interventions to increase activity opportunities for inpatient stroke survivors. DESIGN: Mixed-methods process evaluation underpinned by normalisation process theory (NPT). SETTING: Four post-acute rehabilitation stroke units in England. PARTICIPANTS: Stroke survivors, family members, stroke unit staff, hospital managers, support staff and volunteers. Data informing our NPT analysis comprised: ethnographic observations, n=366 hours; semistructured interviews with 76 staff, 53 stroke survivors and 27 family members pre-EBCD/AEBCD implementation or post-EBCD/AEBCD implementation; and observation of 43 co-design meetings involving 23 stroke survivors, 21 family carers and 54 staff. RESULTS: Former patients and families valued participation in EBCD/AEBCD perceiving they were equal partners in co-design. Staff engaged with EBCD/AEBCD, reporting it as a valuable improvement approach leading to increased activity opportunities. The structured EBCD/AEBCD approach was influential in enabling coherence and cognitive participation and legitimated staff involvement in the change process. Researcher facilitation of EBCD/AEBCD supported cognitive participation, collective action and reflexive monitoring; these were important in implementing and sustaining co-design activities. Observations and interviews post-EBCD/AEBCD cycles confirmed creation and use of new social spaces and increased activity opportunities in all units. EBCD/AEBCD facilitated engagement with wider hospital resources and local communities, further enhancing activity opportunities. However, outside of structured group activity, many individual staff-patient interactions remained task focused. CONCLUSIONS: EBCD/AEBCD facilitated the development and implementation of environmental changes and revisions to work routines which supported increased activity opportunities in stroke units providing post-acute and rehabilitation care. Former stroke patients and carers contributed to improvements. NPT's generative mechanisms were instrumental in analysis and interpretation of facilitators and barriers at the individual, group and organisational level, and can help inform future implementations of similar approaches

Avoiding catastrophic failure in correlated networks of networks

Networks in nature do not act in isolation but instead exchange information, and depend on each other to function properly. An incipient theory of Networks of Networks have shown that connected random networks may very easily result in abrupt failures. This theoretical finding bares an intrinsic paradox: If natural systems organize in interconnected networks, how can they be so stable? Here we provide a solution to this conundrum, showing that the stability of a system of networks relies on the relation between the internal structure of a network and its pattern of connections to other networks. Specifically, we demonstrate that if network inter-connections are provided by hubs of the network and if there is a moderate degree of convergence of inter-network connection the systems of network are stable and robust to failure. We test this theoretical prediction in two independent experiments of functional brain networks (in task- and resting states) which show that brain networks are connected with a topology that maximizes stability according to the theory.Comment: 40 pages, 7 figure

The littoral sea cucumbers (Echinodermata: Holothuroidea) of Guam re-assessed - a diversity curve that still does not asymptote

The Micronesian island of Guam has been an important site for the study of littoral tropical holothuriantaxonomy for almost 200 years. Despite substantial attention by both expeditions and resident taxonomists, new records arestill regularly added to the fauna, demonstrating the challenge of documenting even such large and well-known animals ina small hyper-diverse area. Guam is the type locality of species described by Quoy & Gaimard (1833) and Brandt (1835).A survey of the sea cucumber fauna by Rowe & Doty (1977) led to one of the most used guides for the identification oftropical Pacific sea cucumbers because of the color illustrations of living animals it presented. Focus on echinodermsincluding holothurians continued with numerous new records added in the following decades. Paulay (2003a) summarizedthe fauna last, recording 46-47 species. At this stage the fauna was thought to be well documented. A week-long workshopon holothurian systematics sponsored by the National Science Foundation PEET (Partnerships for Enhancing Expertise inTaxonomy) project in 2010 included a substantial field work component, sampling both during the day and night, withsnorkeling and SCUBA, across a variety of habitats. This survey yielded 40 species, including numerous new records andeven species. Further sampling by Kerr’s lab since the workshop has added additional records. The littoral holothuroidfauna of Guam now comprises 65 species in 17 genera and 7 families. Half of the 19 newly recorded species are the resultof unravelling cryptic species in complexes, the other half are based on new collections. Eleven species are known fromsingle specimens, suggesting that much still remains to be learned about the fauna