Mouthfeel Detection Threshold and Instrumental Viscosity of Sucrose and High Fructose Corn Syrup Solutions

ABSTRACT:  Significant mouthfeel differences between diet and regular cola carbonated beverages have been reported; however, the underlying cause of those differences is not well understood. One avenue explored here is the connection between mouthfeel differences and mouthfeel thresholds of model solutions containing sweeteners used in regular carbonated beverages. The objectives of this research were to (1) determine individual and group mouthfeel detection thresholds of sucrose and high fructose corn syrup (HFCS) solutions while suppressing sweet taste; (2) relate individual and group thresholds to viscosity and number of sweetener molecules in solution; and (3) measure and compare the viscosities of commercial carbonated beverages to the viscosities of sucrose and HFCS solutions formulated to the concentrations of individual and group thresholds. The R-index measure by the rating method was used by 21 panelists to evaluate the thickness difference of sucrose and HFCS solutions compared to water using Gymnema sylvestre tea to supress sweet taste. The group mouthfeel detection threshold for sucrose was 16.78%± 8.72% (g/100 mL) and for HFCS was 11.48%± 8.67% (g/100 mL). The average viscosity of regular carbonated beverages is within the viscosity range associated with the group mouthfeel threshold concentrations of sucrose and HFCS solutions, but the average viscosity of diet carbonated beverages is lower than the viscosity range associated with the group mouthfeel detection threshold concentrations of sucrose and HFCS solutions. This research implies that consumers are sensitive enough to detect mouthfeel differences between diet and regular carbonated beverages, albeit the instrumental viscosity difference being small (0.527 mPa ⋅ s).     

Mechano‐ and Photochromism from Bulk to Nanoscale: Data Storage on Individual Self‐Assembled Ribbons

A Pt(II) complex, bearing an oligo‐ethyleneoxide pendant, is able to self‐assemble in ultralong ribbons that display mechanochromism upon nanoscale mechanical stimuli, delivered through atomic force microscopy (AFM). Such observation paves the way to fine understanding and manipulation of the mechanochromic properties of such material at the nanoscale. AFM allows quantitative assessment of nanoscale mechanochromism as arising from static pressure (piezochromism) and from shear‐based mechanical stimuli (tribochromism), and to compare them with bulk pressure‐dependent luminescence observed with diamond‐anvil cell (DAC) technique. Confocal spectral imaging reveals that mechanochromism only takes place within short distance from the localized mechanical stimulation, which allows to design high‐density information writing with AFM nanolithography applied on individual self‐assembled ribbons. Each ribbon hence serves as an individual microsystem for data storage. The orange luminescence of written information displays high contrast compared to cyan native luminescence; moreover, it can be selectively excited with visible light. In addition, ribbons show photochromism, i.e., the emission spectrum changes upon exposure to light, in a similar way as upon mechanical stress. Photochromism is here conveniently used to conceal and eventually erase information previously written with nanolithography by irradiation.     

Proxy‐RED: an AQM scheme for wireless local area networks

Wireless access points (APs) act as bridges between wired and wireless networks. Since the actually available bandwidth in wireless networks is much smaller than the bandwidth in wired networks, there is a disparity in channel capacity which makes the access point a significant network congestion point in the downstream direction. A current architectural trend in wireless local area networks (WLAN) is to move functionality from APs to a centralized gateway in order to reduce cost and improve features. In this paper, we study the use of RED, a well known active queue management (AQM) scheme, and explicit congestion notification (ECN) to handle bandwidth disparity between the wired and the wireless interface of an access point. Then, we propose the Proxy‐RED scheme, as a solution for reducing the AQM overhead from the access point. Simulations‐based performance analysis indicates that the proposed Proxy‐RED scheme improves the overall performance of a network. In particular, the Proxy‐RED scheme significantly reduces packet loss rate and improves goodput for a small buffer, and minimizes delay for a large buffer size. Copyright © 2006 John Wiley & Sons, Ltd.     

Anchoring of bovine chromosomes 4, 6, 7, 10, and 14 linkage group telomeric ends via FISH analysis of lambda clones

We report the placement of 34 new microsatellite (ms) markers, isolated from a lambda phage genomic clone library, on the bovine genetic map by linkage to published markers. Five of these markers lie at or near the ends of linkage groups and are used to establish chromosomal coverage and orientation. Fluorescence in situ hybridization (FISH) analysis demonstrates that the linkage groups on the U.S. Meat Animal Research Center (MARC) map extend to the telomeric region of Chromosomes (Chrs) 7 and 10. Linkage groups on Chrs 4, 6, and 14 appear to be less inclusive.     

Variational Recursive Joint Estimation of Dense Scene Structure and Camera Motion from Monocular High Speed Traffic Sequences

We present an approach to jointly estimating camera motion and dense structure of a static scene in terms of depth maps from monocular image sequences in driver-assistance scenarios. At each instant of time, only two consecutive frames are processed as input data of a joint estimator that fully exploits second-order information of the corresponding optimization problem and effectively copes with the non-convexity due to both the imaging geometry and the manifold of motion parameters. Additionally, carefully designed Gaussian approximations enable probabilistic inference based on locally varying confidence and globally varying sensitivity due to the epipolar geometry, with respect to the high-dimensional depth map estimation. Embedding the resulting joint estimator in an online recursive framework achieves a pronounced spatio-temporal filtering effect and robustness. We evaluate hundreds of images taken from a car moving at speed up to 100 km/h and being part of a publicly available benchmark data set. The results compare favorably with two alternative settings: stereo based scene reconstruction and camera motion estimation in batch mode using multiple frames. They, however, require a calibrated camera pair or storage for more than two frames, which is less attractive from a technical viewpoint than the proposed monocular and recursive approach. In addition to real data, a synthetic sequence is considered which provides reliable ground truth.     

Intersubband decay of 1-D exciton resonances in carbon nanotubes

We have studied intersubband decay of E22 excitons in semiconducting carbon nanotubes experimentally and theoretically. Photoluminescence excitation line widths of semiconducting nanotubes with chiral indicess (n,m) can be mapped onto a connectivity grid with curves of constant (n - m) and (2n + m). Moreover, the global behavior of E22 line widths is best characterized by a strong increase with energy irrespective of their (n-m)mod(3) = +/-1 family affiliation. Solution of the Bethe-Salpeter equations shows that the E22 line widths are dominated by phonon assisted coupling to higher momentum states of the E11 and E12 exciton bands. The calculations also suggest that the branching ratio for decay into exciton bands vs free carrier bands, respectively is about 10:1.