An amphitropic cAMP-binding protein in yeast mitochondria

ABSTRACT: We describe the first example of a mitochondrial protein with a covalently attached phos-phatidylinositol moiety acting as a membrane anchor. The protein can be metabolically labeled with both stearic acid and inositol. The stearic acid label is removed by phospholipase D whereupon the protein with the retained inositol label is released from the membrane. This protein is a cAMP receptor of the yeast Saccharomyces cereuisiae and tightly associated with the inner mitochondrial membrane. However, it is converted into a soluble form during incubation of isolated mitochondria with Ca2+ and phospholipid (or lipid derivatives). This transition requires the action of a proteinaceous, N-ethylmaleimide-sensitive component of the intermembrane space and is accompanied by a decrease in the lipophilicity of the cAMP receptor. We propose that the component of the intermembrane space triggers the amphitropic behavior of the mitochondrial lipid-modified CAMP-binding protein through a phospholipase activity. Only in recent years specific fatty acids have been recog-nized to play important roles in the association of proteins with membranes. Both noncovalent and covalent interactions be-tween fatty acids and proteins have been reported. Among the latter are GTP-binding proteins (Molenaar et al., 1988)

Probing the polymer-electrode interface using neutron reflection

We demonstrate that neutron reflection (NR) can be used to characterize polymer films deposited on indium tin oxide (ITO). When the chloro precursor to poly[2-(2(')-ethylhexyloxy)5-methoxy-1,4-phenylenevinylene] (MEHPPV) was spin-coated onto ITO NR revealed that between the ITO and the uniform polymer layer was a 20 Angstrom thick low contact zone. We found that the conversion of the chloro precursor to MEHPPV at 180 degreesC under vacuum gave a uniform film of MEHPPV with the layer of low contact between the polymer and ITO remaining. Finally, the NR profile suggests that the blueshift in the MEHPPV absorption spectrum on ITO when compared to quartz is due to polymer morphology and not incomplete conversion. (C) 2003 American Institute of Physics

Categorising Visual Hallucinations in Early Parkinson's Disease.

BACKGROUND: Visual hallucinations (VHs) are common in Parkinson's disease (PD), with prevalence ranging from 27-50% in cross-sectional cohorts of patients with well-established disease. However, minor hallucinations may occur earlier in the disease process than has been previously reported. OBJECTIVE: We sought to categorise VHs in a cohort of newly diagnosed PD patients and establish their relationship to other clinical features. METHODS: Newly diagnosed PD participants (n = 154) were recruited as part of the Incidence of Cognitive Impairment in Cohorts with Longitudinal Evaluation in PD (ICICLE-PD) study. Participants completed the Movement Disorders Society Unified Parkinson's Disease Rating Scale (MDS-UPDRS III), Montreal Cognitive Assessment (MoCA) and Parkinson's Disease Questionnaire (PDQ-39) to assess motor severity, cognition and quality of life (QoL), respectively. VHs were classified using the North East Visual Hallucinations Inventory. Hierarchical regression was used to build predictive models of motor severity, QoL and cognition. RESULTS: 22% (n = 34) of participants experienced recurrent VHs with minor VHs being most frequently reported (64.7% of hallucinators). Complex VHs were present in 32.4% of hallucinating participants. Linear regression showed VHs predicted poorer PDQ-39 and MoCA scores (β= 0.201, p = 0.006 and β= - 0.167, p = 0.01, respectively) but not motor severity (p > 0.05). CONCLUSIONS: Over a fifth of people with newly diagnosed PD reported recurrent VHs; minor hallucinations were the most common, although a small proportion reported complex VHs. Recurrent VHs were found to be a significant independent predictor of cognitive function and QoL but not motor severity. Our findings highlight the importance of screening for VHs at diagnosis.ICICLE-PD was funded by Parkinson’s UK (J-0802, G-1301, G-1507). The research was supported by the Lockhart Parkinson’s Disease Research Fund, the National Institute for Health Research (NIHR) Newcastle Biomedical Research Unit based at Newcastle upon Tyne Hospitals NHS Foundation Trust and Newcastle University and a NIHR Biomedical Research Centre award to the University of Cambridge/Addenbrooke’s Hospital

Triplet exciton diffusion and phosphorescence quenching in Iridium(III)-Centered dendrimers

A study of triplet-triplet exciton annihilation and nonradiative decay in films of iridium(III)-centered phosphorescent dendrimers is reported. The average separation of the chromophore was tuned by the molecular structure and also by blending with a host material. It was found that triplet exciton hopping is controlled by electron exchange interactions and can be over 600 times faster than phosphorescence quenching. Nonradiative decay occurs by weak dipole-dipole interactions and is independent of exciton diffusion, except in very thin films

Investigating situated cultural practices through cross-sectoral digital collaborations: policies, processes, insights

The (Belfast) Good Friday Agreement represents a major milestone in Northern Ireland's recent political history, with complex conditions allowing for formation of a ‘cross-community’ system of government enabling power sharing between parties representing Protestant/loyalist and Catholic/nationalist constituencies. This article examines the apparent flourishing of community-focused digital practices over the subsequent ‘post-conflict’ decade, galvanised by Northern Irish and EU policy initiatives armed with consolidating the peace process. Numerous digital heritage and storytelling projects have been catalysed within programmes aiming to foster social processes, community cohesion and cross-community exchange. The article outlines two projects—‘digital memory boxes’ and ‘interactive galleon’—developed during 2007–2008 within practice-led PhD enquiry conducted in collaboration with the Nerve Centre, a third-sector media education organisation. The article goes on to critically examine the processes involved in practically realising, and creatively and theoretically reconciling, community-engaged digital production in a particular socio-political context of academic-community collaboration

Radio polarimetric imaging of the interstellar medium: magnetic field and diffuse ionized gas structure near the W3/W4/W5/HB3 complex

We have used polarimetric imaging to study the magneto-ionic medium of the Galaxy, obtaining 1420 MHz images with an angular resolution of 1' over more than 40 square-degrees of sky around the W3/W4/W5/HB3 HII region/SNR complex in the Perseus Arm. Features detected in polarization angle are imposed on the linearly polarized Galactic synchrotron background emission by Faraday rotation arising in foreground ionized gas having an emission measure as low as 1 cm^{-6} pc. Several new remarkable phenomena have been identified, including: mottled polarization arising from random fluctuations in a magneto-ionic screen that we identify with a medium in the Perseus Arm, probably in the vicinity of the HII regions themselves; depolarization arising from very high rotation measures (several times 10^3 rad m^{-2}) and rotation measure gradients due to the dense, turbulent environs of the HII regions; highly ordered features spanning up to several degrees; and an extended influence of the HII regions beyond the boundaries defined by earlier observations. In particular, the effects of an extended, low-density ionized halo around the HII region W4 are evident, probably an example of the extended HII envelopes postulated as the origin of weak recombination-line emission detected from the Galactic ridge. Our polarization observations can be understood if the uniform magnetic field component in this envelope scales with the square-root of electron density and is 20 microG at the edge of the depolarized region around W4, although this is probably an over-estimate since the random field component will have a significant effect.Comment: 18 pages, 8 figures (7 jpeg and 1 postscript), accepted for publication in the Astrophysical Journa

Risk aversion in a performativity culture – what can we learn from teachers’ curriculum decision making in history?

Using the notion of risk aversion, this study explores the decisions teachers make when constructing a curriculum. Adopting a qualitative, grounded approach, this study used semi-structured interviews with nine history teachers to examine the decisions they were making during a period of considerable curriculum change in England. Five key categories were identified, which were then defined as risk averse or high risk. The findings show that teachers largely adopt a low risk approach when constructing a curriculum. In particular choice of content, pedagogical and assessment approaches are affected. Also, changes to the curriculum in high stakes examination courses have a major distorting impact on the curriculum choices for the phase of schooling prior to the examination course. This study would suggest that teachers generally aim to maximise examination outcomes through adopting a low risk approach to curriculum change. However, according to the literature, these low risk approaches appear unlikely to improve examination outcomes, whilst at the same time narrowing students’ experience of the curriculum