999 resultados para ELECTRODE POSITION


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With temperatures in the Arctic rising at twice the pace of anywhere else in the world, the European Union (EU) decided in 2008 to begin formulating an overall Arctic policy tackling maritime, environmental, energy and transport challenges. This attempt to draft a comprehensive policy on a topic that the EU had rarely touched upon unavoidably ran up against other existing strategies from Arctic and non-Arctic states. Against this background, this paper examines whether the EU’s current Arctic policy is conducive to framing a strategy that is both correctly targeted and flexible enough to represent Europe’s interests. It shows that the EU’s approach can serve as an effective foreign policy tool to establish the Union’s legitimacy as an Arctic player. However, the EU’s Arctic policy is still underestimating its potential to find common grounds with the strategic partners Russia and China. A properly targeted Arctic policy could help influence Russia over the EU’s interests in the Northern Sea Route and strengthen cooperation with China in an endeavour to gain recognition as relevant Arctic players.

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The acute hippocampal brain slice preparation is an important in vitro screening tool for potential anticonvulsants. Application of 4-aminopyridine (4-AP) or removal of external Mg2+ ions induces epileptiform bursting in slices which is analogous to electrical brain activity seen in status epilepticus states. We have developed these epileptiform models for use with multi-electrode arrays (MEAs), allowing recording across the hippocampal slice surface from 59 points. We present validation of this novel approach and analyses using two anticonvulsants, felbamate and phenobarbital, the effects of which have already been assessed in these models using conventional extracellular recordings. In addition to assessing drug effects on commonly described parameters (duration, amplitude and frequency), we describe novel methods using the MEA to assess burst propagation speeds and the underlying frequencies that contribute to the epileptiform activity seen. Contour plots are also used as a method of illustrating burst activity. Finally, we describe hitherto unreported properties of epileptiform bursting induced by 100M4-AP or removal of external Mg2+ ions. Specifically, we observed decreases over time in burst amplitude and increase over time in burst frequency in the absence of additional pharmacological interventions. These MEA methods enhance the depth, quality and range of data that can be derived from the hippocampal slice preparation compared to conventional extracellular recordings. It may also uncover additional modes of action that contribute to anti-epileptiform drug effects