2,492 research outputs found

    Subjective localization of electrocutaneous stimuli

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    Studying the perception of spatiotemporal stimulus patterns in various modalities may yield important information on the way in which humans process sensory information. The perception of tactile and nociceptive cutaneous stimulus patterns have been studied by Stolle et al. [1] and Trojan et al. [2][4] respectively. Among other things, both authors studied subjective localization of single stimuli. In Trojan et al. [4], two types of mislocalization patterns were observed for nociceptive single stimuli when comparing the localization reports with the stimulus locations: (1) overall proximal or distal displacement and (2) expansion or contraction of the stimulus area.\ud It is unknown whether tactile and nociceptive stimuli at the same skin site are perceived as being at the same site. Therefore, comparing the spatial perception of tactile and nociceptive cutaneous stimuli may provide new insights into their processing. This comparison can only be successfully made by applying nociceptive and tactile stimuli at the same skin site in the same experiment. This can be done by using a device which has recently been developed at our institute and which we refer to as the bimodal stimulation electrode [3]. \ud Recording the perceived locations of stimuli can be done by letting subjects report these on a scale. The most intuitive scale for this is the stimulated arm itself. However, this would bias the perception of stimulus location by providing visual information of the electrode locations. The goal of the present research was to (1) create and (2) test a setup which allows subjects to report perceived stimulus locations on their own arm without seeing the electrode positions. This was achieved by building a setup consisting of a touch screen (Provision Visboard) which presents a digital image of the subject’s own arm (without electrodes) and which is positioned over this arm after the electrodes have been attached. Subjects can report the localizations by pointing at the screen using a pointer

    Mass transfer, fluid flow and membrane properties in flat and corrugated plate hyperfiltration modules

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    Concentration polarisation, decreasing the efficiency in membrane separation processes, can be reduced by increasing mass transfer between membrane surface and bulk of the feed stream. Analogous to techniques used in plate heat exchangers efforts have been made to enhance mass transfer in a plate hyperfiltration module by using a corrugated membrane in stead of a flat one. The corrugations are pressed into an originally flat membrane. These corrugations do not only have an influence on the mass transfer, but also on such membrane properties as salt and water permeability. Corrugations enhance mass transfer in a more effective way than increase of flow rate does.\ud \ud The effect of the corrugations on membrane properties shows a large spread. For corrugated membranes prepared by our group, flux increases of 100% at almost the same or even slightly higher retentions have been obtained

    Omineca Herald, July, 13, 1966

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    We derive a real gravity equation and gain several new insights that were hidden in the nominal specification used so far. Most importantly, the real effective exchange rate (REER) of the exporter and, via the importer's terms of trade, also the importer's REER matter, and we can identify the elasticity of substitution. We estimate real gravity for 18 OECD countries. Therefore, we extend the untangling normalization method from an “it” to an “ijt” panel data model and use it to exploit all variables proposed by theory, despite a broad set of fixed effects (FE). We find that both REERs are important and estimate an elasticity of substitution of 1.5. If we assume homogeneous parameters, as is common, the remaining unexplained exporter-time and importer-time deviations are still substantial, relaxing this assumption improves this. We now explain 64 and 70% of the exporter-time and importer-time deviations, respectively, and thus the majority of the exporter and importer multilateral resistances. Untangling normalization helps to get a better view of what is still unexplained by theory

    ALMA CO J=6-5 observations of IRAS16293-2422: Shocks and entrainment

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    Observations of higher-excited transitions of abundant molecules such as CO are important for determining where energy in the form of shocks is fed back into the parental envelope of forming stars. The nearby prototypical and protobinary low-mass hot core, IRAS16293-2422 (I16293) is ideal for such a study. The source was targeted with ALMA for science verification purposes in band 9, which includes CO J=6-5 (E_up/k_B ~ 116 K), at an unprecedented spatial resolution (~0.2", 25 AU). I16293 itself is composed of two sources, A and B, with a projected distance of 5". CO J=6-5 emission is detected throughout the region, particularly in small, arcsecond-sized hotspots, where the outflow interacts with the envelope. The observations only recover a fraction of the emission in the line wings when compared to data from single-dish telescopes, with a higher fraction of emission recovered at higher velocities. The very high angular resolution of these new data reveal that a bow shock from source A coincides, in the plane of the sky, with the position of source B. Source B, on the other hand, does not show current outflow activity. In this region, outflow entrainment takes place over large spatial scales, >~ 100 AU, and in small discrete knots. This unique dataset shows that the combination of a high-temperature tracer (e.g., CO J=6-5) and very high angular resolution observations is crucial for interpreting the structure of the warm inner environment of low-mass protostars.Comment: Accepted for publication in A&A Letter

    Trade spill-overs of fiscal policy in the European Union: a panel analysis

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    We explore the international spill-overs from fiscal policy shocks via trade in Europe. A fiscal expansion stimulates domestic activity, which leads to more foreign exports and, hence, higher foreign output. To quantify this, we combine a panel VAR model in government spending, net taxes and GDP with a panel trade model. We find statistically significant spill-overs. Our baseline estimates imply that, on average, over the first two years a German public spending increase equal to 1% of GDP implies an average foreign exports gain of 2.2% of its annual level. The corresponding figure for an equal-size net tax reduction is 0.8%. As far as the direct effect of enhanced exports on foreign activity is concerned, the corresponding average gains from the two shocks are, respectively, 0.13% and 0.07% of annual GDP. Of course, these numbers are (substantially) smaller when the fiscal shock originates from smaller EU countries
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