366 research outputs found
Changes in Dopamine Signalling Do Not Underlie Aberrant Hippocampal Plasticity in a Mouse Model of Huntington's Disease
Altered dopamine receptor labelling has been demonstrated in presymptomatic and symptomatic Huntington's disease (HD) gene carriers, indicating that alterations in dopaminergic signalling are an early event in HD. We have previously described early alterations in synaptic transmission and plasticity in both the cortex and hippocampus of the R6/1 mouse model of Huntington's disease. Deficits in cortical synaptic plasticity were associated with altered dopaminergic signalling and could be reversed by D1- or D2-like dopamine receptor activation. In light of these findings we here investigated whether defects in dopamine signalling could also contribute to the marked alteration in hippocampal synaptic function. To this end we performed dopamine receptor labelling and pharmacology in the R6/1 hippocampus and report a marked, age-dependent elevation of hippocampal D1 and D2 receptor labelling in R6/1 hippocampal subfields. Yet, pharmacological inhibition or activation of D1- or D2-like receptors did not modify the aberrant synaptic plasticity observed in R6/1 mice. These findings demonstrate that global perturbations to dopamine receptor expression do occur in HD transgenic mice, similarly in HD gene carriers and patients. However, the direction of change and the lack of effect of dopaminergic pharmacological agents on synaptic function demonstrate that the perturbations are heterogeneous and region-specific, a finding that may explain the mixed results of dopamine therapy in HD
Assessing the efficacy of coproduction to better understand the barriers to achieving sustainability in NHS chronic kidney services and create alternate pathways
CONTEXT: Too many people living with chronic kidney disease are opting for and starting on hospitalâbased dialysis compared to a homeâbased kidney replacement therapy. Dialysis services are becoming financially unsustainable. OBJECTIVE: This study aimed to assess the efficacy of coproductive research in chronic kidney disease service improvement to achieve greater sustainability. DESIGN: A 2âyear coproductive service improvement study was conducted with multiple stakeholders with the specific intention of maximizing engagement with the national health kidney services, patients and public. SETTING AND PARTICIPANTS: A national health kidney service (3 health boards, 18 dialysis units), patients and families (nâ=â50), multidisciplinary teams including doctors, nurses, psychologists, social workers, and so forth (nâ=â68), kidney charities, independent dialysis service providers and wider social services were part of this study. FINDINGS: Coproductive research identified underutilized resources (e.g., patients on home dialysis and social services) and their potential, highlighted unmet social care needs for patients and families and informed service redesign. Education packages were reimagined to support the home dialysis agenda including opportunities for wider service input. The impacts of one size fits all approaches to dialysis on specialist workforce skills were made clearer and also professional, patient and public perceptions of key sustainability policies. DISCUSSION AND CONCLUSIONS: Patient and key stakeholders mapped out new ways to link services to create more sustainable models of kidney health and social care. Maintaining principles of knowledge coproduction could help achieve financial sustainability and move towards more prudent adult chronic kidney disease services. PATIENT OR PUBLIC CONTRIBUTION: Involved in developing research questions, study design, management and conduct, interpretation of evidence and dissemination
Maintaining the momentum in cryoEM for biological discovery
Cryo-electron microscopy (cryoEM) has been transformed over the last decade, with continual new hardware and software tools coming online, pushing the boundaries of what is possible and the nature and complexity of projects that can be undertaken. Here we discuss some recent trends and new tools which are creating opportunities to make more effective use of the resources available within facilities (both staff and equipment). We present approaches for the stratification of projects based on risk and known information about the projects, and the impacts this might have on the allocation of microscope time. We show that allocating different resources (microscope time) based on this information can lead to a significant increase in âsuccessfulâ use of the microscope, and reduce lead time by enabling projects to âfail fasterâ. This model results in more efficient and sustainable cryoEM facility operation
Spitzer IRS spectroscopy of 3CR radio galaxies and quasars: Testing the unified schemes
With the Spitzer Space Telescope Infrared Spectrograph (IRS) we have observed
seven powerful FR2 radio galaxies and seven quasars. Both samples, the galaxies
and the quasars, are comparable in isotropic 178 MHz luminosity (10^26.5 W/Hz <
P 178MHz < 10^29.5 W/Hz) and in redshift range (0.05 < z < 1.5). We find for
both samples similar distributions in the luminosity ratios of high- to
low-excitation lines ([NeV] 14.3 mu / [NeII] 12.8 mu) and of high-excitation
line to radio power ([NeV] 24.3 \mu / P 178MHz). This solves the long debate
about the apparent difference of quasars and radio galaxies in favor of the
orientation-dependent unified schemes. Furthermore, the luminosity ratio [OIII]
500.7 nm / [OIV] 25.9 mu of most galaxies is by a factor of ten lower than that
of the quasars. This suggests that the optical emission from the central NLR is
essentially absorbed (A_V} > 3) in the powerful FR2 galaxies and that the
[OIII] 500.7 nm luminosity does not serve as isotropic tracer for testing the
unified schemes.Comment: 5 pages, 3 figures, accepted as Letter for A&
Hyeropic shift after LASIK induced Diffuse lamellar keratitis
BACKGROUND: Diffuse lamellar keratitis (DLK) is a relatively new syndrome that is increasingly being reported after LASIK. We have observed that a hyperopic shift may be associated with the occurrence of this diffuse lamellar keratitis. CASE PRESENTATION: A 26 year old man developed bilateral diffuse lamellar keratitis (DLK) following myopic LASIK. The residual refractive error was +0.5D OD and +0.25D OS at the end of the first week. The sterile infiltrates resolved over a period of 4â6 weeks on topical steroid therapy. A progressive hyperopic shift was noted in the right eye with an error +4.25Dsph/+0.25Dcyl 20 at the final follow up 6 months post surgery. CONCLUSION: Diffuse lamellar keratitis after LASIK may be associated with a significant hyperopic shift
Dysfunctional Dopaminergic Neurones in Mouse Models of Huntington's Disease: A Role for SK3 Channels
Huntington's disease (HD) is a late-onset fatal neurodegenerative disorder caused by a CAG trinucleotide repeat expansion in the gene coding for the protein huntingtin and is characterised by progressive motor, psychiatric and cognitive decline. We previously demonstrated that normal synaptic function in HD could be restored by application of dopamine receptor agonists, suggesting that changes in the release or bioavailability of dopamine may be a contributing factor to the disease process
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Leo Strauss and International Relations: The politics of modernity's abyss
This article argues that an engagement with the political philosophy of Leo Strauss is of considerable value in International Relations (IR), in relation to the study of both recent US foreign policy and contemporary IR theory. The question of Straussian activities within and close to the foreign policy-making establishment in the United States during the period leading up to the 2003 invasion of Iraq has been the focus of significant scholarly and popular attention in recent years. This article makes the case that several individuals influenced by Strauss exercised considerable influence in the fields of intelligence production, the media and think tanks, and traces the ways in which elements of Straussâ thought are discernible in their interventions in these spheres. It further argues that Straussâ political philosophy is of broader significance for IR insofar as it can be read as a securitising response to the dangers he associated with the foundationlessness of the modern condition. The article demonstrates that the politics of this response are of crucial importance for contemporary debates between traditional and critical IR theorists
How authentic leadership influences team performance:the mediating role of team reflexivity
This study examines how authentic leadership influences team performance via the mediating mechanism of team reflexivity. Adopting a self-regulatory perspective, we propose that authentic leadership will predict the specific team regulatory process of reflexivity, which in turn will be associated with two outcomes of team performance; effectiveness and productivity. Using survey data from 53 teams in three organizations in the United Kingdom and Greece and controlling for collective trust, we found support for our stated hypotheses with the results indicating a significant fully mediated relationship. As predicted the self-regulatory behaviors inherent in the process of authentic leadership served to collectively shape team behavior, manifesting in the process of team reflexivity, which, in turn, positively predicted team performance. We conclude with a discussion of how this study extends theoretical understanding of authentic leadership in relation to teamwork and delineate several practical implications for leaders and organizations
Exploring the âimpactâ in Impact sourcing ventures: a sociology of space perspective
Using qualitative methods this paper explores the lived experience of individuals employed in impact sourcing ventures. In doing so, the paper attempts to understand âimpactâ from the point of view of beneficiaries. The paper, drawing on Georg Simmelâs work on the sociology of space, explores how space influences the lived experience of beneficiaries in ImS ventures. The findings highlight the various strategies adopted by beneficiaries to navigate the dialectical tensions experienced as a result of living and working in the new (ImS workplace) and the old (community) space. The paper also draws attention to the multifaceted nature of impact
Uncoupling the functions of CALM in VAMP sorting and clathrin-coated pit formation.
CALM (clathrin assembly lymphoid myeloid leukemia protein) is a cargo-selective adaptor for the post-Golgi R-SNAREs VAMPs 2, 3, and 8, and it also regulates the size of clathrin-coated pits and vesicles at the plasma membrane. The present study has two objectives: to determine whether CALM can sort additional VAMPs, and to investigate whether VAMP sorting contributes to CALM-dependent vesicle size regulation. Using a flow cytometry-based endocytosis efficiency assay, we demonstrate that CALM is also able to sort VAMPs 4 and 7, even though they have sorting signals for other clathrin adaptors. CALM homologues are present in nearly every eukaryote, suggesting that the CALM family may have evolved as adaptors for retrieving all post-Golgi VAMPs from the plasma membrane. Using a knockdown/rescue system, we show that wild-type CALM restores normal VAMP sorting in CALM-depleted cells, but that two non-VAMP-binding mutants do not. However, when we assayed the effect of CALM depletion on coated pit morphology, using a fluorescence microscopy-based assay, we found that the two mutants were as effective as wild-type CALM. Thus, we can uncouple the sorting function of CALM from its structural role
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