Fish responses to flow velocity and turbulence in relation to size, sex and parasite load

Riverine fish are subjected to heterogeneous flow velocities and turbulence and may use this to their advantage by selecting regions that balance energy expenditure for station holding while maximizing energy gain through feeding opportunities. This study investigated microhabitat selection by guppies Poecilia reticulata in terms of flow characteristics generated by hemisphere boulders in an open channel flume. Velocity and turbulence influenced the variation in swimming behaviour with respect to size, sex and parasite intensity. With increasing body length, fish swam further and more frequently between boulder regions. Larger guppies spent more time in the areas of high-velocity and low-turbulence regions beside the boulders, whereas smaller guppies frequented the low-velocity and high-turbulence regions directly behind the boulders. Male guppies selected the regions of low velocity, indicating possible reduced swimming ability owing to hydrodynamic drag imposed by their fins. With increasing Gyrodactylus turnbulli burden, fish spent more time in regions with moderate velocity and lowest turbulent kinetic energy which were the most spatially and temporally homogeneous in terms of velocity and turbulence. These findings highlight the importance of heterogeneous flow conditions in river channel design owing to the behavioural variability within a species in response to velocity and turbulence

The worldwide costs of marine protected areas

Declines in marine harvests, wildlife, and habitats have prompted calls at both the 2002 World Summit on Sustainable Development and the 2003 World Parks Congress for the establishment of a global system of marine protected areas (MPAs). MPAs that restrict fishing and other human activities conserve habitats and populations and, by exporting biomass, may sustain or increase yields of nearby fisheries. Here we provide an estimate of the costs of a global MPA network, based on a survey of the running costs of 83 MPAs worldwide. Annual running costs per unit area spanned six orders of magnitude, and were higher in MPAs that were smaller, closer to coasts, and in high-cost, developed countries. Models extrapolating these findings suggest that a global MPA network meeting the World Parks Congress target of conserving 20–30% of the world’s seas might cost between $5 billion and$19 billion annually to run and would probably create around one million jobs. Although substantial, gross network costs are less than current government expenditures on harmful subsidies to industrial fisheries. They also ignore potential private gains from improved fisheries and tourism and are dwarfed by likely social gains from increasing the sustainability of fisheries and securing vital ecosystem services

Size-correlated division of labour and spatial distribution of workers in the driver ant, Dorylus molestus

Driver ants ( Dorylus spp.) show a high degree of worker polymorphism. Previous reports suggest that large Dorylus workers are specialised for defensive tasks. In this study, we first quantitatively tested whether there is a size-correlated division of defensive labour among workers. Second, we determined whether the spatial distribution of workers outside the nest can be predicted based on such size-specific differences in task allocation. We show that the division of defensive behaviour among different-sized workers is not strict. However, there is a significant correlation between worker size and the tendency to carry out defensive tasks. First, workers of larger size were more likely than smaller workers to participate in colony defence. Second, larger workers were more frequent near the nest containing the reproducing individuals and the brood. Finally, large workers were more common in open sections of the trail than in covered sections, which are likely to be less exposed to predators

Acute inflammation sensitizes knee-innervating sensory neurons and decreases mouse digging behavior in a TRPV1-dependent manner.

Ongoing, spontaneous pain is characteristic of inflammatory joint pain and reduces an individual's quality of life. To understand the neural basis of inflammatory joint pain, we made a unilateral knee injection of complete Freund's adjuvant (CFA) in mice, which reduced their natural digging behavior. We hypothesized that sensitization of knee-innervating dorsal root ganglion (DRG) neurons underlies this altered behavior. To test this hypothesis, we performed electrophysiological recordings on retrograde labeled knee-innervating primary DRG neuron cultures and measured their responses to a number of electrical and chemical stimuli. We found that 24-h after CFA-induced knee inflammation, knee neurons show a decreased action potential generation threshold, as well as increased GABA and capsaicin sensitivity, but have unaltered acid sensitivity. The inflammation-induced sensitization of knee neurons persisted for 24-h in culture, but was not observed after 48-h in culture. Through immunohistochemistry, we showed that the increased knee neuron capsaicin sensitivity correlated with enhanced expression of the capsaicin receptor, transient receptor potential vanilloid 1 (TRPV1) in knee-innervating neurons of the CFA-injected side. We also observed an increase in the co-expression of TRPV1 with tropomyosin receptor kinase A (TrkA), which is the receptor for nerve growth factor (NGF), suggesting that NGF partially induces the increased TRPV1 expression. Lastly, we found that systemic administration of the TRPV1 antagonist, A-425619, reversed the decrease in digging behavior induced by CFA injection, further confirming the role of TRPV1, expressed by knee neurons, in acute inflammatory joint pain.S.C. was supported by a Gates Cambridge Trust scholarship and L.A.P. was supported by the University of Cambridge BBSRC Doctoral Training Programme (BB/M011194/1)

Supporting care home residents in the last year of life through ‘Needs Rounds’: Development of a pre-implementation programme theory through a rapid collaborative online approach

2023 Macgregor, McCormack, Spilsbury, Hockley, Rutherford, Ogden, Soulsby, Mckenzie, Hanratty and Forbat.Background: Realist evaluation aims to address the knowledge to practice gap by explaining how an intervention is expected to work, as well as what is likely to impact upon the success of its implementation, by developing programme theories that link contexts, mechanisms and outcomes. Co-production approaches to the development of programme theories offer substantial benefits in addressing power relations, including and valuing different types of knowledge, and promoting buy-in from stakeholders while navigating the complex social systems in which innovations are embedded. This paper describes the co-production of an initial programme theory of how an evidence based intervention developed in Australia - called ‘Palliative Care Needs Rounds’ – might work in England and Scotland to support care home residents approaching their end of life. Methods: Using realist evaluation and iPARIHS (integrated Promoting Action on Research Implementation in Health Services) we sought to determine how contexts and mechanisms of change might shape implementation outcomes. Pre-intervention online interviews (n = 28) were conducted (February-April 2021), followed by four co-design online workshops with 43 participants (April-June 2021). The online interviews and workshops included a range of stakeholders, including care home staff, specialist palliative care staff, paramedics, general practitioners, and relatives of people living in care homes. Results: This methodology paper reports developments in realist evaluation and co-production methodologies, and how they were used to develop context, mechanisms, outcomes (CMOs) configurations, and chains of inference. The initial (pre-intervention) programme theory is used to illustrate this process. Two developments to iPARIHS are described. First, involving stakeholders in the collaborative co-design workshops created opportunities to commence facilitation. Second, we describe developing iPARIHS’ innovation component, to include novel stakeholder interpretations, perceptions and anticipated use of the intervention as they participated in workshop discussions. Conclusions: This rapid and robust co-production methodology draws on interactive collaborative research practices (interviews, workshop discussions of data, illustrative vignettes and visual methods). These innovative and engaging methods can be packaged for online processes to develop, describe and interrogate the CMOs in order to co-produce a programme theory. These approaches also commence facilitation and innovation, and can be adopted in other implementation science and realist studies

Can REDD+ social safeguards reach the ‘right’ people? Lessons from Madagascar

AbstractThere is extensive debate about the potential impact of the climate mechanism REDD+ on the welfare of forest-dwelling people. To provide emission reductions, REDD+ must slow the rate of deforestation and forest degradation: such a change will tend to result in local opportunity cost to farmers at the forest frontier. Social safeguard processes to mitigate negative impacts of REDD+ are being developed and can learn from existing safeguard procedures such as those implemented by the World Bank. Madagascar has a number of REDD+ pilot projects with World Bank support including the Corridor Ankeniheny-Zahamena (CAZ). Nearly two thousand households around the corridor have been identified as ‘project affected persons’ (PAPs) and given compensation. We compare households identified as project affected persons with those not identified. We found households with more socio-political power locally, those with greater food security, and those that are more accessible were more likely to be identified as eligible for compensation while many people likely to be negatively impacted by the REDD+ project did not receive compensation. We identify three issues which make it difficult for a social safeguard assessment to effectively target the households for compensation: (a) poor information on location of communities and challenging access means that information does not reach remote households; (b) reluctance of people dependant on shifting agriculture to reveal this due to government sanctions; and (c) reliance by safeguard assessors on non-representative local institutions. We suggest that in cases where the majority of households are likely to bear costs and identification of affected households is challenging, the optimal, and principled, strategy may be blanket compensation offered to all the households in affected communities; avoiding the dead weight costs of ineffective safeguard assessments. The Paris Agreement in December 2015 recognised REDD+ as a key policy instrument for climate change mitigation and explicitly recognised the need to respect human rights in all climate actions. However, safeguards will be prone to failure unless those entitled to compensation are aware of their rights and enabled to seek redress where safeguards fail. This research shows that existing safeguard commitments are not always being fulfilled and those implementing social safeguards in REDD+ should not continue with business as usual

Assessing the effects of water flow rate on parasite transmission amongst a social host

Many freshwater habitats are subject to change through time. Specifically, natural flow regimes are substantially modified by not only seasonal climatic change, but also anthropogenic activity. Consequently, freshwater organisms are exposed to variable flow, potentially altering their behaviour and subsequently parasite transmission amongst social hosts. Here, we investigate the effects of flow conditions on the shoaling behaviour of Trinidadian guppies (Poecilia reticulata), and the resulting transmission of a directly transmitted ectoparasite, Gyrodactylus turnbulli. Shoals exposed to continuous flow exhibited significantly greater G. turnbulli peak intensities and abundance when compared to fish subjected to interrupted, but not no-flow conditions. Parasite transmission rate was greater in shoals exposed to interrupted flow, resulting in parasites becoming more distributed amongst shoal members and thus reducing mean intensity in comparison to continuous flow shoals. Furthermore, as prevalence increased, the distance between shoaling conspecifics increased at greater rates in interrupted and no-flow conditions compared to continuous flow: indicating that in the absence of flowing water, parasitism has a greater effect on shoaling decisions. This data highlights how fish behaviourally respond to variable flow conditions and the implications for parasite transmission

A comparison of the development of audiovisual integration in children with autism spectrum disorders and typically developing children

This study aimed to investigate the development of audiovisual integration in children with Autism Spectrum Disorder (ASD). Audiovisual integration was measured using the McGurk effect in children with ASD aged 7–16 years and typically developing children (control group) matched approximately for age, sex, nonverbal ability and verbal ability. Results showed that the children with ASD were delayed in visual accuracy and audiovisual integration compared to the control group. However, in the audiovisual integration measure, children with ASD appeared to ‘catch-up’ with their typically developing peers at the older age ranges. The suggestion that children with ASD show a deficit in audiovisual integration which diminishes with age has clinical implications for those assessing and treating these children