569 research outputs found
The Evolution and Diversity of SALMFamide Neuropeptides
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
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
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 Unionâs 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
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,
fronts, labyrinths and 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
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
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 likeâ: Autistic adultsâ views and experiences of stimming
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.âStereotyped or repetitive motor movementsâ are characterised as core features in the diagnosis of autism, yet many
autistic adults (and the neurodiversity movement) have reclaimed them as âstimmingâ. 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 othersâ 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
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 ), starting from the
nonlinear Schr\"odinger limit (for which ). 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
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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