Subjective localization of electrocutaneous stimuli

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

The Performance of Multi-Factor Term Structure Models for Pricing and Hedging Caps and Swaptions

In this paper we empirically compare different term structure models when it comes to the pricing and hedging of caps and swaptions.We analyze the influence of the number of factors on the pricing and hedging results, and investigate which type of data -interest rate data or derivative price data- should be used to estimate the model parameters to obtain the best pricing and hedging results. We use data on interest rates, and cap and swaption prices from 1995 to 1999.We find that models with two or three factors imply better out-of-sample predictions of cap and swaption prices than one-factor models.Also, estimation on the basis of derivative prices leads to more accurate out-of-sample prediction of cap and swaption prices than estimation on the basis of interest rate data.The empirical results on the hedging of caps and swaptions show that, if the number of hedge instruments is equal to the number of factors, the multi-factor models outperform one-factor models in hedging caps and swaptions. However, if one uses a large set of hedge instruments, one-factor models perform as well as multi-factor models.term structure of interest rates;option pricing;hedging;derivatives

Classifying the saline seeps of a region into best-management groupings

Non-Peer Reviewedover 60 salinity investigations have been completed within a 9 township area near Avonlea, Saskatchewan. This level of study has provided detailed information on a large number of seeps. These have been grouped according to their common features and general landscape position, creating 3 seep classes: Uplands/Side-hill; Plains Transitional; and Bedrock Controlled. Recommendations from detailed farmer reports and local hydrogeologic test sites have been used to derive "best management" strategies for each seep class. This approach will provide direction toward the treatment of future salinity requests, while promoting the realistic management of existing seeps

Efficient estimation in the semiparametric normal regression-copula model with a focus on QTL mapping

The semiparametric normal copula model is studied with a correlation matrix that depends on a covariate. The bivariate version of this regression-copula model has been proposed for statistical analysis of Quantitative Trait Loci (QTL) via twin data. Appropriate linear combinations of Van der Waerden’s normal scores rank correlation coefficients yield $\sqrt{n}$-consistent estimators of the coefficients in the correlation function, i.e. of the regression parameters. They are used to construct semiparametrically efficient estimators of the regression parameters

Determination of molecular spectroscopic parameters and energy-transfer rates by double-resonance spectroscopy

The spectroscopy of small to medium-size polyatomic molecules can be extremely complex, especially in higher-lying overtone and combination vibrational levels. The high density of levels also complicates the understanding of inelastic collision processes, which is required to model energy transfer and collision broadening of spectral lines. Both of these problems can be addressed by double-resonance spectroscopy, i.e., time-resolved pump-probe measurements using microwave, infrared, near-infrared, and visible-wavelength sources. Information on excited-state spectroscopy, transition moments, inelastic energy transfer rates and propensity rules, and pressure-broadening parameters may be obtained from such experiments. Examples are given for several species of importance in planetary atmospheres, including ozone, silane, ethane, and ammonia