Internet robots: a new robotics niche

Web robots are a concept that has captured the interest of researchers and developers. Their potential is being investigated at the University of Western Australia, where a six-axis robot has been made teleoperable over the World Wide Web. The site has been active since September 1994 and the robot has also been exhibited at the Australian National Science and Technology Centre in Canberra. Someone considering offering services with this technology will be interested in which groups of people find it attractive, the level of commitment that operators show, and how the robot users behave. These questions are addressed in the article with some demographic data on operators, an analysis of how long they remain interested, and an examination of how long they will wait to access the service. The user interface affects operator behavior, so some interface variations and their effect on operator actions are considered. The opportunities presented, likely application areas, and the potential for generating an income are examined     

Physical Maltreatment Victim to Antisocial Child: Evidence of an Environmentally Mediated Process.

The well-documented finding that child physical maltreatment predicts later antisocial behavior has at least 2 explanations: (a) Physical maltreatment causes antisocial behavior, and (b) genetic factors transmitted from parents to children influence the likelihood that parents will be abusive and that children will engage in antisocial behavior. The authors tested these hypotheses in the representative Environmental-Risk cohort of 1,116 twin pairs and their families, who were assessed when the twins were 5 and 7 years old. Mothers reported on children's experience of physical maltreatment, and mothers and teachers reported on children's antisocial behavior. The findings support the hypothesis that physical maltreatment plays a causal role in the development of children's antisocial behavior and that preventing maltreatment can prevent its violent sequelae. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Automated surgical screwdriver: automated screw placement

The use of power screwdrivers and drills for tapping and screw insertion in surgery is becoming more common. It has been established from clinical observations that the use of a small air drill for inserting self-tapping screws provides improved coaxial alignment and precision, and that the drill should be stopped before the screw head is completely seated on the plate, presumably to reduce the risk of over-tightening. The risk of overrun and over-tightening during tapping and screw insertion is increased with the use of power tools. Prevention of over-tightening is dependent upon when the surgeon detects the onset of tightening, both visually and from the feel of the rapid increase in torque. If detection is too late, then over-tightening or stripping can occur. This study is concerned with using a mechatronic screwdriver to control the tapping depth and to prevent the over-tightening of screws. The effects of various parameters upon the torque profile during tapping and screw insertion have been investigated in synthetic bone and sheep tibia. An automated system is proposed for preventing over-tightening of pre-tapped and self-tapping screws when attaching a surgical plate to a sheep tibia in vitro. The system was used to attach a plate to a sheep tibia using self-tapping screws. The mean torque of the screws inserted using the automated system was 35 per cent of the stripping torque.     

THE USE OF PESTICIDES IN MALTINGS,BREWERIES AND DISTILLERIES APRIL 1974 - MARCH 1975

A survey of the use of pesticides in maltings, breweries and distilleries during the period April 1974 to March 1975 was made by the Pesticides Survey Group at the Ministry of Agriculture's Pest Infestation Control Laboratory at Slough in collaboration with the Department of Agriculture and Fisheries for Scotland. A breakdown of the insecticides and rodenticides used, including quantities and numbers of users, is given. The results show that in most cases, the official recommended measures to control pests are being followed.     

Book Review

Abstract

Data Base Directions, The Next Steps. John L. Berg, Editor. U. S. Department of Commerce, National Bureau of Standards. (Order from Superintendent of Documents, U. S. Government Printing Office, Washington, DC, 20402. Ask f o r SD Cat.No. C13.10:451.) 158 pages; $2.45.     

A low-noise front-end for multiplexed ENG recording using CMOS technology

Multi-electrode cuffs have been proposed as a means for the parallel recording of naturally-occurring neural signals. Compared to a conventional tripole cuff providing a single channel signal, additional information about the velocity and direction of nerve signals can be extracted from the multi-electrode recordings. Moreover, interference suppression is improved and overall power consumption reduced, as the analysis shows. In this paper a new recording system is proposed, each channel of which consists of a low-noise preamplifier employing lateral bipolar transistors to provide an impedance match to the tissue and a path to ground for the switching currents of a single high-gain amplifier, which is multiplexed between the channels. The proposed system provides low-noise, low-power operation and practically identical channel gains and is suitable for integration in a larger CMOS-based system.     

Effects of bovine somatotropin on dry matter intake, milk yield and body temperature in Holstein and Jersey cows during heat stress

Thirty-one lactating Holstein and Jersey cows were used to determine the effect of daily injections of 0 or 20 mg of recombinant bST in hot, humid weather. The comparison period lasted 80 d, from mid-June through August. The maximum and minimum ambient temperature and relative humidity averaged 34.6 and 22.2 degrees C and 100 and 59.8%, respectively. Body temperatures of somatotropin-treated Holsteins were elevated over controls by .2 and .3 degrees C at the a.m. and p.m. milkings, respectively, whereas corresponding treatment effects for Jerseys were .5 and .6 degrees C, thus demonstrating a breed by treatment interaction. The response of milk and FCM yields and apparent efficiency of production to somatotropin administration depended on the level of production prior to treatment. Cows at low pretreatment production increased milk and FCM yields to a greater degree than did cows at higher production. A breed by treatment interaction showed that Holsteins increased milk and FCM yields more than Jerseys upon administration of somatotropin. Intake of DM was not affected by treatment. Cows administered bST lost BW and condition score. Greater heat stress was associated with the higher milk production of cows administered bST.     

Error Probability of FSK Incoherent Diversity Reception with Fast Rice Fading

In this paper we compute the error performanceof noncoherent detection receivers for FSK signalstransmitted over fast frequency-flat Rician fadingchannels. Linearly time-varying fading models are used to derive closed-form expressions for the errorprobability of binary FSK signaling. Error bounds areestablished for the performance of M-ary orthogonal FSK.Simulation results are in excellent agreement with analytical predictions.     

A quantum amplifier model for predicting temporal variations in theoutput power from a semiconductor laser on a picosecond time scale

A new model for simulating temporal fluctuations in the power emitted by a semiconductor laser is described. Light in the cavity is assumed to circulate in the form of traveling photon packets, in which the photon number fluctuates due to the processes of spontaneous emission, stimulated emission, absorption, scattering, and reflection. The dipole dephasing time T plays a critical role in modeling the interaction of the photon packets and gain medium. The Monte Carlo method is used to simulate the temporal behavior of a continuously pumped Fabry-Perot laser. The laser output power is found to exhibit periodic fluctuations at the cavity transit time frequency (longitudinal mode beat frequency). The amplitude of these fluctuations, as well as the relaxation oscillation, which occurs at a much lower frequency, is strongly influenced by the magnitude of T. The results of these simulations are related to the temporal behavior expected from a conventional FP laser