Potential climatic transitions with profound impact on Europe

We discuss potential transitions of six climatic subsystems with large-scale impact on Europe, sometimes denoted as tipping elements. These are the ice sheets on Greenland and West Antarctica, the Atlantic thermohaline circulation, Arctic sea ice, Alpine glaciers and northern hemisphere stratospheric ozone. Each system is represented by co-authors actively publishing in the corresponding field. For each subsystem we summarize the mechanism of a potential transition in a warmer climate along with its impact on Europe and assess the likelihood for such a transition based on published scientific literature. As a summary, the ‘tipping’ potential for each system is provided as a function of global mean temperature increase which required some subjective interpretation of scientific facts by the authors and should be considered as a snapshot of our current understanding. <br/

La politique économique des enclaves minières au Pérou

Kruijt Dirk, Vellinga Menno. La politique économique des enclaves minières au Pérou. In: Tiers-Monde, tome 18, n°72, 1977. pp. 797-832

Industrialización y desarrollo regional

Lo primero que se le ocurre al lector al incluir la lectura de este trabajo es que su título debe haberse referido a la industrialización y al desarrollo regional del Valle del Cauca, u otro título similar que señalara la región específica del estudio. El propósito anunciado por los autores del trabajo es encontrar respuesta a una serie de preguntas que ellos planteasn en la presentación o prólogo (pág. 6); para encontrar las respuestas los autores deciden concentrarse en dos grandes temas: 1. El Valle de Cauca como caso específico y 2. Las políticas de descentralización y desconcentración propuestas por el gobierno nacional

Reducing interaction in simultaneous paired stimulation with CI.

In this study simultaneous paired stimulation of electrodes in cochlear implants is investigated by psychophysical experiments in 8 post-lingually deaf subjects (and one extra subject who only participated in part of the experiments). Simultaneous and sequential monopolar stimulation modes are used as references and are compared to channel interaction compensation, partial tripolar stimulation and a novel sequential stimulation strategy named phased array compensation. Psychophysical experiments are performed to investigate both the loudness integration during paired stimulation at the main electrodes as well as the interaction with the electrode contact located halfway between the stimulating pair. The study shows that simultaneous monopolar stimulation has more loudness integration on the main electrodes and more interaction in between the electrodes than sequential stimulation. Channel interaction compensation works to reduce the loudness integration at the main electrodes, but does not reduce the interaction in between the electrodes caused by paired stimulation. Partial tripolar stimulation uses much more current to reach the needed loudness, but shows the same interaction in between the electrodes as sequential monopolar stimulation. In phased array compensation we have used the individual impedance matrix of each subject to calculate the current needed on each electrode to exactly match the stimulation voltage along the array to that of sequential stimulation. The results show that the interaction in between the electrodes is the same as monopolar stimulation. The strategy uses less current than partial tripolar stimulation, but more than monopolar stimulation. In conclusion, the paper shows that paired stimulation is possible if the interaction is compensated

Simulated potential along the array and currents per electrode of the CI for the different stimulation strategies.

<p>The current graphs on the bottom of the figure represent the currents from which the potentials are calculated for each stimulation method. The currents are based on the same current vector for each stimulation method. Then the currents are compensated with the compensation methods to acquire the shown data. </p

The subjective loudness is plotted against the largest current on the array, averaged over 9 subjects.

<p>On the left (A) this is done for pair 5 and on the right (B) for pair 3.</p

The threshold of hearing at electrode number 9 for each stimulation strategy, normalized to the sMP stimulation strategy, for both pair 3 (dark grey) and pair 5 (light grey).

<p>The asterisk indicates a significant deviation from the sMP paradigm (p<0.01). A total of 8 subjects participated in this experiment. The whiskers indicate the minimum and maximum value, the boxes the upper and lower quartile and the filled circles are outliers.</p

Clinical and biographical data on the subjects included in this study.

<p>Clinical and biographical data on the subjects included in this study.</p