1,833 research outputs found

    Sport mega-event volunteers' motivations and postevent intention to volunteer: The Sydney World Masters Games, 2009

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    Ā© 2015 Cognizant Comm. Corp. Investment in mega-sport events is frequently justified on the basis that there are infrastructure and social legacies that remain after the event. This research explores the claims of a social legacy through a pre-and post-Games survey of volunteers at the Sydney World Masters Games 2009 (SWMG). Through online surveys the research explores pre-and post-volunteer motivations, postevent volunteering intentions before the Games and actual volunteer behavior after the Games. The pre-Games survey supports previous research that a desire to be involved in the event motivates people to volunteer. However, the postevent expression of motivations shifted to a more altruistic focus. The postevent volunteering intentions as indicated in the preevent survey would support the claim of a social legacy; however, this was not supported by the postevent measures of volunteering levels. The use of a pre-and postevent survey has highlighted that the timing of measures of motivations can influence responses and one may not depend on preevent intentions as an indicator of postevent behaviors

    Incorporating intraspecific trait variation into functional diversity: Impacts of selective logging on birds in Borneo

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    1. As conservation increasingly recognises the importance of speciesā€™ functional roles in ecosystem processes, studies are shifting away from measuring species richness towards measures that account for the functional differences between species in a community. These functional diversity (FD) indices have received much recent attention and refinement, but their greatest limitation remains their inability to incorporate information about intraspecific trait variation (ITV). 2. We use an individual-based model to account for ITV when calculating the functional diversity of two avian communities in Borneo; one in primary (unlogged) forest and one in selectively logged forest. We deal with the scarcity of trait data for individual species by developing a simulation approach, taking data from the literature where necessary. Using a bootstrapping procedure, we produce a range of ecologically feasible FD values taking account of ITV for five commonly-used FD indices, and we quantify the confidence that can be placed in these values using a newly-developed bootstrapping method: btFD. 3. We found that incorporating ITV significantly altered the FD values of all indices used in our models. The rank order of FD for the two communities, indicating whether diversity was higher in primary or selectively logged forest, was largely unchanged by the inclusion of ITV. However, by accounting for ITV, we were able to reveal previously unrecognized impacts of selective logging on avian functional diversity through a narrower dispersion of individuals in functional trait space in logged forest. 4. Our results highlight the importance of incorporating ITV into measures of functional diversity, whilst our simulation approach addresses the frequently encountered difficulty of working with sparse trait data and quantifies the confidence that should be placed in such findings

    The ducky^{2J} Mutation in Cacna2d2 Results in Reduced Spontaneous Purkinje Cell Activity and Altered Gene Expression

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    The mouse mutant ducky and its allele ducky^{2J} represent a model for absence epilepsy characterized by spike-wave seizures and cerebellar ataxia. These mice have mutations in Cacna2d2, which encodes the Ī±ā‚‚Ī“-2 calcium channel subunit. Of relevance to the ataxic phenotype, Ī±ā‚‚Ī“-2 mRNA is strongly expressed in cerebellar Purkinje cells (PCs). The Cacna2d2du2J mutation results in a 2 bp deletion in the coding region and a complete loss of Ī±ā‚‚Ī“-2 protein. Here we show that du^{2J}/du^{2J} mice have a 30% reduction in somatic calcium current and a marked fall in the spontaneous PC firing rate at 22Ā°C, accompanied by a decrease in firing regularity, which is not affected by blocking synaptic input to PCs. At 34Ā°C, du^{2J}/du^{2J} PCs show no spontaneous intrinsic activity. DU^{2J}/du^{2J} mice also have alterations in the cerebellar expression of several genes related to PC function. At postnatal day 21, there is an elevation of tyrosine hydroxylase mRNA and a reduction in tenascin-C gene expression. Although du^{2J}/+ mice have a marked reduction in Ī±ā‚‚Ī“-2 protein, they show no fall in PC somatic calcium currents or increase in cerebellar tryrosine hydroxylase gene expression. However, du^{2J}/+ PCs do exhibit a significant reduction in firing rate, correlating with the reduction in Ī±ā‚‚Ī“-2. A hypothesis for future study is that effects on gene expression occur as a result of a reduction in somatic calcium currents, whereas effects on PC firing occur as a long-term result of loss of Ī±ā‚‚Ī“-2 and/or a reduction in calcium currents and calcium-dependent processes in regions other than the soma

    Differentiation of human fetal mesenchymal stem cells into cells with an oligodendrocyte phenotype

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    This article is available open access through the publisherā€™s website at the link below. Copyright @ 2009 Landes Bioscience.The potential of mesenchymal stem cells (MSC) to differentiate into neural lineages has raised the possibility of autologous cell transplantation as a therapy for neurodegenerative diseases. We have identified a population of circulating human fetal mesenchymal stem cells (hfMSC) that are highly proliferative and can readily differentiate into mesodermal lineages such as bone, cartilage, fat and muscle. Here, we demonstrate for the first time that primary hfMSC can differentiate into cells with an oligodendrocyte phenotype both in vitro and in vivo. By exposing hfMSC to neuronal conditioned medium or by introducing the pro-oligodendrocyte gene, Olig-2, hfMSC adopted an oligodendrocyte-like morphology, expressed oligodendrocyte markers and appeared to mature appropriately in culture. Importantly we also demonstrate the differentiation of a clonal population of hfMSC into both mesodermal (bone) and ectodermal (oligodendrocyte) lineages. In the developing murine brain transplanted hfMSC integrated into the parenchyma but oligodendrocyte differentiation of these naĆÆve hfMSC was very low. However, the proportion of cells expressing oligodendrocyte markers increased significantly (from 0.2% to 4%) by pre-exposing the cells to differentiation medium in vitro prior to transplantation. Importantly, the process of in vivo differentiation occurred without cell fusion. These findings suggest that hfMSC may provide a potential source of oligodendrocytes for study and potential therapy

    Tropical land-use change alters trait-based community assembly rules for dung beetles and birds

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    Tropical rainforest disturbance and conversion are critical drivers of biodiversity loss. A key knowledge gap is understanding the impacts of habitat modification on mechanisms of community assembly, which are predicted to respond differently between taxa and across spatial scales. We use a null model approach to detect trait assembly of species at local- and landscape-scales, and then subdivide communities with different habitat associations and foraging guilds to investigate whether the detection of assembly mechanisms varies between groups. We focus on two indicator taxa, dung beetles and birds, across a disturbance gradient of primary rainforest, selectively logged rainforest, and oil palm plantations in Borneo, Southeast Asia. Random community assembly was predominant for dung beetles across habitats, whereas trait convergence, indicative of environmental filtering, occurred across the disturbance gradient for birds. Assembly patterns at the two spatial scales were similar. Subdividing for habitat association and foraging guild revealed patterns hidden when focusing on the overall community. Dung beetle forest specialists and habitat generalists showed opposing assembly mechanisms in primary forest, community assembly of habitat generalists for both taxa differed with disturbance intensity, and insectivorous birds strongly influenced overall community assembly relative to other guilds. Our study reveals the sensitivity of community assembly mechanisms to anthropogenic disturbance via a shift in the relative contribution of stochastic and deterministic processes. This highlights the need for greater understanding of how habitat modification alters species interactions and the importance of incorporating speciesā€™ traits within assessments

    Experimental observation of the breaking and recombination of single Cooper pairs

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    We observe the real-time breaking of single Cooper pairs by monitoring the radio-frequency impedance of a superconducting double quantum dot. The Cooper pair breaking rate in the microscale islands of our device decreases as temperature is reduced, saturating at 2 kHz for temperatures beneath 100 mK. In addition, we measure in real-time the quasiparticle recombination into Cooper pairs. Analysis of the recombination rates shows that, in contrast to bulk lms, a multi-stage recombination pathway is followed.A.J.F. would like to acknowledge the Hitachi Research fellowship, support from Hitachi Cambridge Laboratory and support from the EPSRC grant EP/H016872/1. B.W.L. is supported by a Royal Society University Research Fellowship. F.A.P. would like to thank the Leverhulme Trust for fi nancial support.This is the author accepted manuscript. The final version is available from APS via http://dx.doi.org/10.1103/PhysRevB.90.14050

    Negative Regulator of Ubiquitin-Like Protein 1 modulates the autophagy-lysosomal pathway via p62 to facilitate the extracellular release of tau following proteasome impairment

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    Negative regulator of ubiquitin-like protein 1 (NUB1) and its longer isoform NUB1L are ubiquitin-like (UBL)/ubiquitin-associated (UBA) proteins that facilitate the targeting of proteasomal substrates, including tau, synphilin-1 and huntingtin. Previous data revealed that NUB1 also mediated a reduction in tau phosphorylation and aggregation following proteasome inhibition, suggesting a switch in NUB1 function from targeted proteasomal degradation to a role in autophagy. Here, we delineate the mechanisms of this switch and show that NUB1 interacted specifically with p62 and induced an increase in p62 levels in a manner facilitated by inhibition of the proteasome. NUB1 moreover increased autophagosomes and the recruitment of lysosomes to aggresomes following proteasome inhibition. Autophagy flux assays revealed that NUB1 affected the autophagyā€“lysosomal pathway primarily via the UBA domain. NUB1 localized to cytosolic inclusions with pathological forms of tau, as well as LAMP1 and p62 in the hippocampal neurons of tauopathy mice. Finally, NUB1 facilitated the extracellular release of tau following proteasome inhibition. This study thus shows that NUB1 plays a role in regulating the autophagyā€“lysosomal pathway when the ubiquitin proteasome system is compromised, thus contributing to the mechanisms targeting the removal of aggregation-prone proteins upon proteasomal impairment

    A Genome-wide gene-expression analysis and database in transgenic mice during development of amyloid or tau pathology

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    We provide microarray data comparing genome-wide differential expression and pathology throughout life in four lines of "amyloid" transgenic mice (mutant human APP, PSEN1, or APP/PSEN1) and "TAU" transgenic mice (mutant human MAPT gene). Microarray data were validated by qPCR and by comparison to human studies, including genome-wide association study (GWAS) hits. Immune gene expression correlated tightly with plaques whereas synaptic genes correlated negatively with neurofibrillary tangles. Network analysis of immune gene modules revealed six hub genes in hippocampus of amyloid mice, four in common with cortex. The hippocampal network in TAU mice was similar except that Trem2 had hub status only in amyloid mice. The cortical network of TAU mice was entirely different with more hub genes and few in common with the other networks, suggesting reasons for specificity of cortical dysfunction in FTDP17. This Resource opens up many areas for investigation. All data are available and searchable at http://www.mouseac.org

    Timing of elective pre-labour caesarean section : AĀ decision analysis

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    BWM is supported by a NHMRC Practitioner Fellowship (GNT1082548), and reports consultancy for ObsEva, Merck and Guerbet.Peer reviewedPublisher PD

    Dynamic range of GSK3Ī± not GSK3Ī² is essential for bidirectional synaptic plasticity at hippocampal CA3-CA1 synapses.

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    Glycogen synthase kinase-3 (GSK3), particularly the isoform GSK3Ī², has been implicated in a wide range of physiological systems and neurological disorders including Alzheimer's Disease. However, the functional importance of GSK3Ī± has been largely untested. The multifunctionality of GSK3 limits its potential as a drug target because of inevitable side effects. Due to its greater expression in the CNS, GSK3Ī² rather than GSK3Ī± has also been assumed to be of primary importance in synaptic plasticity. Here, we investigate bidirectional long-term synaptic plasticity in knockin mice with a point mutation in GSK3Ī± or GSK3Ī² that prevents their inhibitory regulation. We report that only the mutation in GSK3Ī± affects long-term potentiation (LTP) and depression (LTD). This stresses the importance of investigating isoform specificity for GSK3 in all systems and suggests that GSK3Ī± should be investigated as a drug target in cognitive disorders including Alzheimer's Disease
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