Cerebral F18 -FDG PET CT in Children: Patterns during Normal Childhood and Clinical Application of Statistical Parametric Mapping

The first aim was to recruit and analyse a high quality dataset of cerebral FDG PET CT scans in neurologically normal children. Using qualitative, semi-quantitative and statistical parametric mapping (SPM) techniques, the results showed that a pattern of FDG uptake similar to adults does not occur by one year of age as was previously believed, but the regional FDG uptake changes throughout childhood driven by differing age related regional rates of increasing FDG uptake. The second aim was to use this normal dataset in the clinical analysis of cerebral FDG PET CT scans in children with epilepsy and Neurofibromatosis type 1 (NF1). The normal dataset was validated for single-subject-versus-group SPM analysis and was highly specific for identifying the epileptogenic focus likely to result in a good post-operative outcome in children with epilepsy. Qualitative, semi-quantitative and group-versus-group SPM analyses were applied to FDG PET CT scans in children with NF1. The results showed reduced metabolism in the thalami and medial temporal lobes compared to neurologically normal children. This thesis has produced novel findings that advance the understanding of childhood brain development and has developed SPM techniques that can be applied to cerebral FDG PET CT scans in children with neurological disorders

Vortex Penetration into a Type II Superconductor due to a Mesoscopic External Current

Applying the London theory we study curved vortices produced by an external current near and parallel to the surface of a type II superconductor. By minimizing the energy functional we find the contour describing the hard core of the flux line, and predict the threshold current for entrance of the first vortex. We assume that the vortex entrance is allowed due to surface defects, despite the Bean-Livingston barrier. Compared to the usual situation with a homogeneous magnetic field, the main effect of the present geometry is that larger magnetic fields can be applied locally before vortices enter the superconducting sample. It is argued that this effect can be further enhanced in anisotropic superconductors.Comment: 9 pages, 14 figure

Primary crustal melt compositions: Insights into the controls, mechanisms and timing of generation from kinetics experiments and melt inclusions

We explore the controls, mechanisms and timing of generation of primary melts and their compositions, and show that the novel studies of melt inclusions in migmatites can provide important insights into the processes of crustal anatexis of a particular rock. Partial melting in the source region of granites is dependent on five main processes: (i) supply of heat; (ii) mineral–melt interface reactions associated with the detachment and supply of mineral components to the melt, (iii) diffusion in the melt, (iv) diffusion in minerals, and (v) recrystallization of minerals. As the kinetics of these several processes vary over several orders of magnitude, it is essential to evaluate in Nature which of these processes control the rate of melting, the composition of melts, and the extent to which residue–melt chemical equilibrium is attained under different circumstances. To shed light on these issues, we combine data from experimental and melt inclusion studies. First, data from an extensive experimental program on the kinetics of melting of crustal protoliths and diffusion in granite melt are used to set up the necessary framework that describes how primary melt compositions are established during crustal anatexis. Then, we use this reference frame and compare compositional trends from experiments with the composition of melt inclusions analyzed in particular migmatites. We show that, for the case of El Hoyazo anatectic enclaves in lavas, the composition of glassy melt inclusions provides important information on the nature and mechanisms of anatexis during the prograde suprasolidus history of these rocks, including melting temperatures and reactions, and extent of melt interconnection, melt homogenization and melt–residue equilibrium. Compositional trends in several of the rehomogenized melt inclusions in garnet from migmatites/granulites in anatectic terranes are consistent with diffusion in melt-controlled melting, though trace element compositions of melt inclusions and coexisting minerals are necessary to provide further clues on the nature of anatexis in these particular rocks.This work was supported by the National Science Foundation [grants EAR-9603199, EAR-9618867, EAR-9625517 and EAR-9404658], the Italian Consiglio Nazionale delle Ricerche, the European Commission (grant 01-LECEMA22F through contract No. ERAS-CT-2003-980409; and a H2020 Marie Skłodowska-Curie Actions under grant agreement No. 654606), the Italian Ministry of Education, University and Research (grants PRIN 2007278A22, 2010TT22SC and SIR RBSI14Y7PF), the Università degli Studi di Padova [Progetto di Ateneo CPDA107188/10 and a Piscopia—Marie Curie Fellowship under grant agreement No. 600376], the Australian Research Council (Australian Professorial Fellowship and Discovery Grants Nos. DP0342473 and DP0556700), and the National Research Foundation (South Africa; Incentives For Rated Researchers Program)

Tonic Inhibition Enhances Fidelity of Sensory Information Transmission in the Cerebellar Cortex

Tonic inhibition is a key regulator of neuronal excitability and network function in the brain, but its role in sensory information processing remains poorly understood. The cerebellum is a favorable model system for addressing this question as granule cells, which form the input layer of the cerebellar cortex, permit high-resolution patch-clamp recordings in vivo, and are the only neurons in the cerebellar cortex that express the α6δ-containing GABA(A) receptors mediating tonic inhibition. We investigated how tonic inhibition regulates sensory information transmission in the rat cerebellum by using a combination of intracellular recordings from granule cells and molecular layer interneurons in vivo, selective pharmacology, and in vitro dynamic clamp experiments. We show that blocking tonic inhibition significantly increases the spontaneous firing rate of granule cells while only moderately increasing sensory-evoked spike output. In contrast, enhancing tonic inhibition reduces the spike probability in response to sensory stimulation with minimal effect on the spontaneous spike rate. Both manipulations result in a reduction in the signal-to-noise ratio of sensory transmission in granule cells and of parallel fiber synaptic input to downstream molecular layer interneurons. These results suggest that under basal conditions the level of tonic inhibition in vivo enhances the fidelity of sensory information transmission through the input layer of the cerebellar cortex

Capital works procurement policies in Australia : implications for understanding and meeting client needs

This paper undertakes a case study of procurement through a comparative analysis of the capital works procurement policies of the Commonwealth, State, and Territory Governments in Australia. Capital works procurement policies provide the mechanism by which governments manage procurement processes, and frame how individual government agencies, as clients, participate in those processes. The paper proposes a typology of capital works procurement approaches, together with implications of how these different policies play out for clients. A tentative proposition is advanced that policy approaches to capital works procurement either explicitly or implicitly, make assumptions about the organisational capability of clients to plan and deliver capital works projects, including their ability to understand and articulate their own building needs. Additionally, the paper concludes that innovation has occurred at a policy level in capital works procurement. Recommendations for further research are suggested.<br /

Information Requirements under the Essential-Use Concept: PFAS Case Studies

Per- and polyfluoroalkyl substances (PFAS) are a class of substances for which there are widespread concerns about their extreme persistence in combination with toxic effects. It has been argued that PFAS should only be employed in those uses that are necessary for health or safety or are critical for the functioning of society and where no alternatives are available (“essential-use concept”). Implementing the essential-use concept requires a sufficient understanding of the current uses of PFAS and of the availability, suitability, and hazardous properties of alternatives. To illustrate the information requirements under the essential-use concept, we investigate seven different PFAS uses, three in consumer products and four industrial applications. We investigate how much information is available on the types and functions of PFAS in these uses, how much information is available on alternatives, their performance and hazardous properties and, finally, whether this information is sufficient as a basis for deciding on the essentiality of a PFAS use. The results show (i) the uses of PFAS are highly diverse and information on alternatives is often limited or lacking; (ii) PFAS in consumer products often are relatively easy to replace; (iii) PFAS uses in industrial processes can be highly complex and a thorough evaluation of the technical function of each PFAS and of the suitability of alternatives is needed; (iv) more coordination among PFAS manufacturers, manufacturers of alternatives to PFAS, users of these materials, government authorities, and other stakeholders is needed to make the process of phasing out PFAS more transparent and coherent

Dimeticone 4% liquid gel found to kill all lice and eggs with a single 15 minute application

<p>Abstract</p> <p>Background</p> <p>Dimeticone 4% lotion is an effective and widely accepted treatment for head louse infestation. However, it is a highly mobile fluid that some people find difficult to apply and is mainly left on the hair for 8 hours or overnight. User preference is for a more manageable and viscous product that can be used with a short application time.</p> <p>Findings</p> <p>This proof of concept study in 41 people investigated dimeticone 4% liquid gel, a product that is easier to apply than the lotion, applied for 15 minutes on two occasions a week apart. We found that head lice were eliminated from all participants following the first application of product. We did not find lice of any stage on any participant during four post treatment assessments and particularly, unlike other treatments, no young nymphs on days 1 and 6 prior to the second treatment, indicating ovicidal as well as pediculicidal activity.</p> <p>Conclusions</p> <p>Dimeticone 4% liquid gel has demonstrated efficacy greater than other similar products and the evidence obtained indicates elimination of head louse infestation with a single 15 minute application.</p> <p>Trial registration</p> <p>Current Controlled Trials <a href="http://www.controlled-trials.com/ISRCTN59227204">ISRCTN59227204</a></p

Improving bus service reliability: The Singapore experience

In February 2014, Singapore embarked on a 2-year trial of a Bus Service Reliability Framework (BSRF) to improve en-route bus regularity and reduce instances of bus bunching and prolonged waiting times. Based on London's Quality Incentive Contract, the Singapore model also imposes penalties or provides incentives to operators for increases/reductions of Excess Wait Time (EWT) beyond a certain route-specific baseline. Drawing on insights derived from research on performance-based contracts, this paper describes some key considerations surrounding this particular innovation in Singapore's overall bus regulatory framework. We also discuss an important advancement in our understanding of how bus users value reliability improvements through estimates obtained from stated preference data. At the same time, early indications from the trial have been encouraging