Social Presence and Children: Praise, Intrinsic Motivation, and Learning With Computers

The computers are social actors (CASA) paradigm asserts that human computer users interact socially with computers, and the paradigm has provided extensive evidence that this is the case for adults. This experiment examined whether or not children have similar reactions to computers by comparing children's predictable responses to praise from a teacher to their responses to praise from a computer. Eight- to 10-year-old participants ( N = 42) received either praise or neutral feedback from a computer. Independent variables were the feedback (praise or neutral), and participants' age and gender. Dependent variables measured via a paper-and-pencil questionnaire were learning (recall and recognition memory), perceived ability, and intrinsic motivation. Results provide evidence that children do have social responses to computers and that such social responses can lead to increases in learning (recall and recognition) in young children.     

Optimum bandwidth-distance performance in partial response CPMsystems

The problem of optimizing the baseband pulse shape in order to obtain the minimum effective bandwidth for a prescribed value of minimum Euclidean distance is treated for partial response CPM. Some comparisons with standard pulses are performed and the results are presented in the form of bandwidth-distance and spectral density plots     

Economics of multiple beam satellites

This paper describes an advanced multibeam communications satellite system using on-board processing and hopping beams in conjunction with low-cost earth-stations to derive a significant advantage over fibre optic submarine cable. It serves thousands of small earth-stations located near the origins of traffic. An economic analysis is presented for both this satellite system and competitive fibre optic cable for the 1995 to 2007 epoch. Results indicate the satellite service to be significantly lower in cost, and in addition it delivers the service near to the origin of the traffic, providing additional savings in terrestrial connections.     

Characterisation of frozen orange juice by ultrasound and wavelet analysis

Ultrasound technology was used to analyse the freezing behaviour of orange juice. The ultrasonic properties of orange juice, specifically velocity and attenuation coefficient, were characterised as the temperature was decreased from 20 to ?50 °C. The results were compared with NMR free induction decay data and correlated with the amount of unfrozen water present in the frozen sample. The velocities of longitudinal waves (P‐wave) and shear waves (S‐wave) in frozen orange juice were measured, yielding values of around 4000 and 2000 m s^?1 respectively. They were related to the amount of unfrozen water in the frozen sample. The elastic moduli of the samples at different temperatures were obtained from the measured ultrasonic velocities. Significant changes in the attenuation of the ultrasonic waves propagated through the frozen sample were observed as a result of ice nucleation and growth. Information about the spectral behaviour of the ultrasound signal was obtained by means of wavelet analysis. The analysis provided a direct measure of the spectral content of the ultrasonic waves over time and showed the variation in the ultrasonic velocity dispersion with temperature. Significant velocity dispersions occurred for frequencies less than 1 MHz. Copyright © 2004 Society of Chemical Industry     

The Multiple Roles of CD147 in the Development and Progression of Oral Squamous Cell Carcinoma: An Overview

Cluster of differentiation (CD)147, also termed extracellular matrix metalloprotease inducer or basigin, is a glycoprotein ubiquitously expressed throughout the human body, the oral cavity included. CD147 actively participates in physiological tissue development or growth and has important roles in reactive processes such as inflammation, immunity, and tissue repair. It is worth noting that deregulated expression and/or activity of CD147 is observed in chronic inflammatory or degenerative diseases, as well as in neoplasms. Among the latter, oral squamous cell carcinoma (OSCC) is characterized by an upregulation of CD147 in both the neoplastic and normal cells constituting the tumor mass. Most interestingly, the expression and/or activity of CD147 gradually increase as healthy oral mucosa becomes inflamed; hyperplastic/dysplastic lesions are then set on, and, eventually, OSCC develops. Based on these findings, here we summarize published studies which evaluate whether CD147 could be employed as a marker to monitor OSCC development and progression. Moreover, we describe CD147-promoted cellular and molecular events which are relevant to oral carcinogenesis, with the aim to provide useful information for assessing whether CD147 may be the target of novel therapeutic approaches directed against OSCC.