569 research outputs found

    The Evolution and Diversity of SALMFamide Neuropeptides

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    The SALMFamides are a family of neuropeptides that act as muscle relaxants in echinoderms. Two types of SALMFamides have been identified: L-type (e.g. the starfish neuropeptides S1 and S2) with the C-terminal motif LxFamide (x is variable) and F-type with the C-terminal motif FxFamide. In the sea urchin Strongylocentrotus purpuratus (class Echinoidea) there are two SALMFamide genes, one encoding L-type SALMFamides and a second encoding F-type SALMFamides, but hitherto it was not known if this applies to other echinoderms. Here we report the identification of SALMFamide genes in the sea cucumber Apostichopus japonicus (class Holothuroidea) and the starfish Patiria miniata (class Asteroidea). In both species there are two SALMFamide genes: one gene encoding L-type SALMFamides (e.g. S1 in P. miniata) and a second gene encoding F-type SALMFamides plus one or more L-type SALMFamides (e.g. S2-like peptide in P. miniata). Thus, the ancestry of the two SALMFamide gene types traces back to the common ancestor of echinoids, holothurians and asteroids, although it is not clear if the occurrence of L-type peptides in F-type SALMFamide precursors is an ancestral or derived character. The gene sequences also reveal a remarkable diversity of SALMFamide neuropeptides. Originally just two peptides (S1 and S2) were isolated from starfish but now we find that in P. miniata, for example, there are sixteen putative SALMFamide neuropeptides. Thus, the SALMFamides would be a good model system for experimental analysis of the physiological significance of neuropeptide "cocktails" derived from the same precursor protein

    RAPID: Ecological Resistance of Multiply Stressed Populations: The Response of Tidal Marsh Birds and Plants to Hurricane Sandy

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    All animal and plant populations can weather change. However, the amount of environmental change a population can absorb is likely to depend upon other, past and ongoing stresses that the population experiences. This project will test whether the ability of populations of native plants and animals in coastal marshes to withstand the recent, extreme storm Hurricane Sandy was greater or less in marshes more subject to past stresses. Researchers will compare the abundances of marsh plants and animals before and after the storm and test whether vulnerability was greater in more specialized species or in marshes surrounded by development, invaded by introduced plants, or challenged by high rates of sea-level rise, and whether previous protection of areas from different kinds of development or use helped reduce vulnerability. By addressing these questions using current theories of ecosystem disturbance, the research will provide general insights on the effects of disturbance and stress on native species and habitats. This research also will provide a specific assessment of Hurricane Sandy\u27s impact on tidal marshes, a vital buffer against storm damage. This will help managers target specific marshes for conservation and restoration and improve the efficiency of planned federal restoration efforts. The work will also inform future coastal management planning by identifying which types of marshes are most vulnerable to future disturbances. Findings will be disseminated to local, state, and federal partners through the Saltmarsh Habitat and Avian Research Program, a cooperative consortium of universities, non-governmental organizations, and state and Federal agency partners working together to conserve tidal marsh habitats and the species they support (www.tidalmarshbirds.org). The project will also help train 20 field technicians

    Selective patient and public involvement: The promise and perils of pharmaceutical intervention for autism

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    This is the final version of the article. Available from Wiley via the DOI in this record.BACKGROUND: Guidelines suggest the patient community should be consulted from the outset when designing and implementing basic biomedical research, but such patient communities may include conflicting views. We examined how engagement occurred in one such instance. OBJECTIVE: Our objective was to scrutinize patient and public involvement (PPI) by a pan-European biomedical consortium working to develop drugs to treat autism. We aimed to use this as an example to illustrate how PPI has been utilized in biomedical research. SETTING, PARTICIPANTS AND ANALYSIS: Two public events, one in the UK and one in Denmark were conducted as part of the consortium's on-going PPI activities in 2014 and 2015. Sixty-six individuals submitted written comments on the consortium's research after these events. The textual data produced were analysed using a thematic approach. Approximately 71% of respondents reported themselves to be adults on the autism spectrum or parents of children with autism. RESULTS: The themes identified illustrated major differences between some community concerns and the biomedical research agenda. While treating autism per se. was seen as problematic by some, treating specific co-occurring problems was seen as helpful in some circumstances. The biomedical consortium selected PPI with a limited user viewpoint at its outset and more widely once basic research was on-going. DISCUSSION: This case illustrates what we term "selective PPI" where only a sympathetic and/or limited patient viewpoint is included. Findings highlight the perils of using selective PPI to legitimise scientific endeavours, and the possibilities for constructive dialogue.This work was supported by EU-AIMS (European Autism Interventions), which receives support from the Innovative Medicines Initiative Joint Undertaking under grant agreement no. 115300, the resources of which are composed of financial contributions from the European Union’s Seventh Framework Programme (grant FP7/2007-2013); The first author's work was specifically funded by the Wellcome Trust, Grant number 108676/Z/15/Z

    Frequency Locking in Spatially Extended Systems

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    A variant of the complex Ginzburg-Landau equation is used to investigate the frequency locking phenomena in spatially extended systems. With appropriate parameter values, a variety of frequency-locked patterns including flats, π\pi fronts, labyrinths and 2π/32\pi/3 fronts emerge. We show that in spatially extended systems, frequency locking can be enhanced or suppressed by diffusive coupling. Novel patterns such as chaotically bursting domains and target patterns are also observed during the transition to locking

    Order Parameter Equations for Front Transitions: Planar and Circular Fronts

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    Near a parity breaking front bifurcation, small perturbations may reverse the propagation direction of fronts. Often this results in nonsteady asymptotic motion such as breathing and domain breakup. Exploiting the time scale differences of an activator-inhibitor model and the proximity to the front bifurcation, we derive equations of motion for planar and circular fronts. The equations involve a translational degree of freedom and an order parameter describing transitions between left and right propagating fronts. Perturbations, such as a space dependent advective field or uniform curvature (axisymmetric spots), couple these two degrees of freedom. In both cases this leads to a transition from stationary to oscillating fronts as the parity breaking bifurcation is approached. For axisymmetric spots, two additional dynamic behaviors are found: rebound and collapse.Comment: 9 pages. Aric Hagberg: http://t7.lanl.gov/People/Aric/; Ehud Meron: http://www.bgu.ac.il/BIDR/research/staff/meron.htm

    Identification of a neuropeptide precursor protein that gives rise to a "cocktail" of peptides that bind Cu(II) and generate metal-linked dimers

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    The Transparency document associated with this article can be found,in online version.This work was supported by a Leverhulme Trust grant (RPG-2013-351) awarded to MRE and National Science Foundation (USA) grant awards DEB 1036416, 1036358, 1036366, and 1036368

    People should be allowed to do what they like’: Autistic adults’ views and experiences of stimming

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    This is the final version. Available from the publisher via the DOI in this record.Data from participants who consented will be deposited in the UK Data Service, in 2019.‘Stereotyped or repetitive motor movements’ are characterised as core features in the diagnosis of autism, yet many autistic adults (and the neurodiversity movement) have reclaimed them as ‘stimming’. Supported by a growing body of scientific research, autistic adults argue that these behaviours may serve as useful coping mechanisms, yet little research has examined stimming from the perspective of autistic adults. Through interviews and focus groups, we asked 32 autistic adults to share their perceptions and experiences of stimming, including the reasons they stim, any value doing so may hold for them and their perceptions of others’ reactions to stimming. Using thematic analysis, we identified two themes: stimming as (1) a self-regulatory mechanism and (2) lacking in social acceptance, but can become accepted through understanding. Autistic adults highlighted the importance of stimming as an adaptive mechanism that helps them to soothe or communicate intense emotions or thoughts and thus objected to treatment that aims to eliminate the behaviour.Wellcome TrustLeverhulme Trus

    Multistable Pulse-like Solutions in a Parametrically Driven Ginzburg-Landau Equation

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    It is well known that pulse-like solutions of the cubic complex Ginzburg-Landau equation are unstable but can be stabilised by the addition of quintic terms. In this paper we explore an alternative mechanism where the role of the stabilising agent is played by the parametric driver. Our analysis is based on the numerical continuation of solutions in one of the parameters of the Ginzburg-Landau equation (the diffusion coefficient cc), starting from the nonlinear Schr\"odinger limit (for which c=0c=0). The continuation generates, recursively, a sequence of coexisting stable solutions with increasing number of humps. The sequence "converges" to a long pulse which can be interpreted as a bound state of two fronts with opposite polarities.Comment: 13 pages, 6 figures; to appear in PR

    Breathing Spots in a Reaction-Diffusion System

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    A quasi-2-dimensional stationary spot in a disk-shaped chemical reactor is observed to bifurcate to an oscillating spot when a control parameter is increased beyond a critical value. Further increase of the control parameter leads to the collapse and disappearance of the spot. Analysis of a bistable activator-inhibitor model indicates that the observed behavior is a consequence of interaction of the front with the boundary near a parity breaking front bifurcation.Comment: 4 pages RevTeX, see also http://chaos.ph.utexas.edu/ and http://t7.lanl.gov/People/Aric
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