1,819 research outputs found
Direct Payments in Residential Care Trailblazer Programme Evaluation Preliminary report
This report is the first from the independent evaluation of the âtrailblazersâ. It is based on a scoping study carried out over the summer and autumn of 2013 consisting of a literature review, documentary analysis, interviews (June-September), collation of routine data and collection of descriptive data from trailblazers on their schemes for DPs
Template-Stripped Multifunctional Wedge and Pyramid Arrays for Magnetic Nanofocusing and Optical Sensing
We present large-scale reproducible
fabrication of multifunctional ultrasharp metallic structures on planar
substrates with capabilities including magnetic field nanofocusing
and plasmonic sensing. Objects with sharp tips such as wedges and
pyramids made with noble metals have been extensively used for enhancing
local electric fields via the lightning-rod effect or plasmonic nanofocusing.
However, analogous nanofocusing of magnetic fields using sharp tips
made with magnetic materials has not been widely realized. Reproducible
fabrication of sharp tips with magnetic as well as noble metal layers
on planar substrates can enable straightforward application of their
material and shape-derived functionalities. We use a template-stripping
method to produce plasmonic-shell-coated nickel wedge and pyramid
arrays at the wafer-scale with tip radius of curvature close to 10
nm. We further explore the magnetic nanofocusing capabilities of these
ultrasharp substrates, deriving analytical formulas and comparing
the results with computer simulations. These structures exhibit nanoscale
spatial control over the trapping of magnetic microbeads and nanoparticles
in solution. Additionally, enhanced optical sensing of analytes by
these plasmonic-shell-coated substrates is demonstrated using surface-enhanced
Raman spectroscopy. These methods can guide the design and fabrication
of novel devices with applications including nanoparticle manipulation,
biosensing, and magnetoplasmonics
Spike Timing Dependent Plasticity: A Consequence of More Fundamental Learning Rules
Spike timing dependent plasticity (STDP) is a phenomenon in which the precise timing of spikes affects the sign and magnitude of changes in synaptic strength. STDP is often interpreted as the comprehensive learning rule for a synapse â the âfirst lawâ of synaptic plasticity. This interpretation is made explicit in theoretical models in which the total plasticity produced by complex spike patterns results from a superposition of the effects of all spike pairs. Although such models are appealing for their simplicity, they can fail dramatically. For example, the measured single-spike learning rule between hippocampal CA3 and CA1 pyramidal neurons does not predict the existence of long-term potentiation one of the best-known forms of synaptic plasticity. Layers of complexity have been added to the basic STDP model to repair predictive failures, but they have been outstripped by experimental data. We propose an alternate first law: neural activity triggers changes in key biochemical intermediates, which act as a more direct trigger of plasticity mechanisms. One particularly successful model uses intracellular calcium as the intermediate and can account for many observed properties of bidirectional plasticity. In this formulation, STDP is not itself the basis for explaining other forms of plasticity, but is instead a consequence of changes in the biochemical intermediate, calcium. Eventually a mechanism-based framework for learning rules should include other messengers, discrete change at individual synapses, spread of plasticity among neighboring synapses, and priming of hidden processes that change a synapse's susceptibility to future change. Mechanism-based models provide a rich framework for the computational representation of synaptic plasticity
Neuroimaging of Human Balance Control: A Systematic Review
This review examined 83 articles using neuroimaging modalities to investigate the neural correlates underlying static and dynamic human balance control, with aims to support future mobile neuroimaging research in the balance control domain. Furthermore, this review analyzed the mobility of the neuroimaging hardware and research paradigms as well as the analytical methodology to identify and remove movement artifact in the acquired brain signal. We found that the majority of static balance control tasks utilized mechanical perturbations to invoke feet-in-place responses (27 out of 38 studies), while cognitive dual-task conditions were commonly used to challenge balance in dynamic balance control tasks (20 out of 32 studies). While frequency analysis and event related potential characteristics supported enhanced brain activation during static balance control, that in dynamic balance control studies was supported by spatial and frequency analysis. Twenty-three of the 50 studies utilizing EEG utilized independent component analysis to remove movement artifacts from the acquired brain signals. Lastly, only eight studies used truly mobile neuroimaging hardware systems. This review provides evidence to support an increase in brain activation in balance control tasks, regardless of mechanical, cognitive, or sensory challenges. Furthermore, the current body of literature demonstrates the use of advanced signal processing methodologies to analyze brain activity during movement. However, the static nature of neuroimaging hardware and conventional balance control paradigms prevent full mobility and limit our knowledge of neural mechanisms underlying balance control
Inferred changes in El NiñoâSouthern Oscillation variance over the past six centuries
It is vital to understand how the El NiñoâSouthern Oscillation (ENSO) has responded to past changes in natural and anthropogenic forcings, in order to better understand and predict its response to future greenhouse warming. To date, however, the instrumental record is too brief to fully characterize natural ENSO variability, while large discrepancies exist amongst paleo-proxy reconstructions of ENSO. These paleo-proxy reconstructions have typically attempted to reconstruct ENSO's temporal evolution, rather than the variance of these temporal changes. Here a new approach is developed that synthesizes the variance changes from various proxy data sets to provide a unified and updated estimate of past ENSO variance. The method is tested using surrogate data from two coupled general circulation model (CGCM) simulations. It is shown that in the presence of dating uncertainties, synthesizing variance information provides a more robust estimate of ENSO variance than synthesizing the raw data and then identifying its running variance. We also examine whether good temporal correspondence between proxy data and instrumental ENSO records implies a good representation of ENSO variance. In the climate modeling framework we show that a significant improvement in reconstructing ENSO variance changes is found when combining information from diverse ENSO-teleconnected source regions, rather than by relying on a single well-correlated location. This suggests that ENSO variance estimates derived from a single site should be viewed with caution. Finally, synthesizing existing ENSO reconstructions to arrive at a better estimate of past ENSO variance changes, we find robust evidence that the ENSO variance for any 30 yr period during the interval 1590â1880 was considerably lower than that observed during 1979â2009
Dinge, Du & Ich. Verwendungs- und bedeutungsoffene Materialien in der Lernwerkstattarbeit mit Kindern und Studierenden der KindheitspÀdagogik
Lena S. Kaiser und Tanja Wittenberg analysieren den Einsatz verwendungs- und bedeutungsoffener Materialien innerhalb von Lernwerkstattarbeit mit Kindern und Studierenden der KindheitspĂ€dagogik (Hochschule Emden/Leer). Anhand von videografischen Daten werten die Autorinnen Interaktionsprozesse mit den Materialien und Interaktionsprozesse ĂŒber die Materialien fokussierend aus. Dabei zeigt sich innerhalb der interaktiven Auseinandersetzung der zugleich inspirierende wie irritierende Charakter der mehrdeutigen Materialeigenschaften, der eine reflexive Kultur des Wahrnehmens und Fragens hervorbringen kann. (DIPF/Orig.
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