Inhibition of ingestive behavior following fourth ventricle bombesin injection in chronic decerebrate rats.

Tested the hypothesis that the effects of 4th ventricle bombesin (BN) injection on feeding require interaction with forebrain neural systems by measuring intraoral sucrose (0.1 M) in tube-fed control and tube-fed supracollicular decerebrate rats after 4th ventricle injections of 1, 5, 10, 20, and 50 ng BN. Fourth ventricle injections of all doses of BN reliably suppressed sucrose intake in both control and chronic decerebrate rats. These results indicate that caudal brain-stem afferent signals produced by 4th ventricle BN injections are integrated by the local neural circuitry of the caudal brain stem, independent of the forebrain systems, to modulate ingestive behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The health practices of homeless women: a causal model

A theoretical model was developed and tested to explain the effects of learned helplessness, self-esteem, and depression on the health practices of homeless women. Data were collected from a sample of 122 homeless women recruited from six shelters. Structural equation analysis was used to evaluate the model. Analysis revealed a goodness-of-fit index of 98, indicating a good fit of the model with the data. Overall, the variables in the model accounted for 14% to 21% of the variance in the health practices of homeless women.     

Demodulation of a magnetoresistive sensor signal to achieve a low-cost, stable and high-resolution vector magnetometer

A technique for demodulating a simple a.c. biased magnetoresistor's signal is presented. The application highlighted is the measurement of power-line frequency magnetic fields for the study of their effects on human health. The circuit enables very low magnetic fields to be resolved whilst maintaining a wide d.c. magnetic-field dynamic range with the aid of d.c. feedback in both hard and easy axes of the sensor. The easy-axis feedback field maintains constant sensitivity even under the influence of large easy-axis external fields. Long-term stability is typically better than 20 nT.     

Radiolocation Experiments in an Urban Environment

Many new urban applications of radiolocation technology in both cooperative and noncooperative forms are anticipated in law enforcement and urban planning fields. Until recently, virtually no data were available regarding passive radiolocation of urban targets by conventional techniques such as direction finding. Recent radiolocation experiments performed at 165 kHz and 100 MHz were used to measure transmitter locations with increasing urbanization. Urban radiolocation errors in range and azimuth as a function of urbanization are given for the downtown area of San Antonio, Tex., showing increasing error with increasing urbanization. Procedures to improve urban radiolocation performance are suggested.     

The role of hyperdipsia in aggression following septal lesions in rats.

Lesions of the septum in animal Ss are known to produce an increase in aggressiveness and an increase in water intake. A series of 5 experiments with 120 female Sprague-Dawley rats examined the possibility that aggression is secondary to hyperdipsia. When Ss with septal lesions were restricted to preoperative levels of water intake, aggression scores declined significantly. When Ss without lesions were preloaded with either water or saline, aggression increased. Neither decreased shock threshold nor increased cell hydration provided a full explanation for the results. It is suggested that the aversive nature of the stomach turgescence caused by increased water intake may be an additional mediating factor in septal aggression. (31 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The lantibiotic lacticin 3147 produced in a milk-based medium improves the efficacy of a bismuth-based teat seal in cattle deliberately infected with Staphylococcus aureus

A preparation of the bacteriocin lacticin 3147 (prepared from a demineralized whey protein fermentation liquor) was combined as a powder with a bismuth-based intramammary teat seal and evaluated for its potential as an antimicrobial in non-lactating cows. The lacticin/teat seal formulation enabled significant bacteriocin release from the seal without the requirement for a surfactant. Studies in vivo in lactating cows demonstrated that this formulation was effective in reducing bacterial recoveries (approximately 20-fold) from teats deliberately inoculated with Staphylococcus aureus after infusion. Moreover, this formulation also significantly reduced the numbers of Staph. aureus recovered from teats that were exposed to the challenge bacterium before the infusion of the teat seal preparation. The powdered preparation of lacticin 3147 did, however, cause some teat irritation as evidenced by associated rises in somatic cell count (SCC). However, this effect was short-lived and when the mean SCC readings pre-infusion and the final two readings post-infusion were compared, there was no significant difference in the immunological acceptance between treatments.     

Early prostaglandin release from the ischemic myocardium in the dog

Cellular consequences of myocardial ischemia were studied in anesthetized dogs. Confirmation of myocardial ischemia was provided by electrocardiographic and biochemical indexes. Prostaglandin F2alpha release into coronary venous blood was significantly elevated during myocardial ischemia, whereas indomethacin treatment prevented this increase in coronary venous prostaglandin F2alpha concentrations. No significant increase in prostaglandin E2 release was observed in response to myocardial ischemia, but indomethacin treatment significantly reduced coronary venous prostaglandin E2 concentrations below those of control values. Within one hour after occlusion of the coronary artery, the S-T segment was significantly altered, and coronary venous prostaglandin F2alpha had increased significantly above the control concentration. These changes persisted during four hours of myocardial ischemia. Plasma creatine phosphokinase activity increased significantly after two hours of myocardial ischemia and remained elevated for the subsequent two hours of ischemia. After four hours of myocardial ischemia, myocardial creatine phosphokinase activity of ischemic myocardium was significantly reduced, and labilization of myocardial treatment prevented increases in prostaglandin release but did not influence other biochemical changes or the electrocardiographic response to ischemia. Thus, prostaglandin release by ischemic myocardial tissue is an early response to the ischemic stimulus.     

Direct coking of athabasca tar sand

Yield patterns and product quality have been determined for the direct coking of Athabasca tar sand. Temperature and vapor residence time are the key variables affecting yield; tar sand residence time has a minor impact in yield provided that a minimum contact time is achieved. Yields are not sensitive to the composition of tar sand feed. Yields from direct coking are similar to those from commercial bitumen coking processes; previously reported variations in direct coking yields can be reconciled when liquid product endpoint and coking severity are considered. Coke deposited on the sand is readily burned, producing a flue gas high in SO₂ and particulates, and a free-flowing sand. The sand settles readily from a slurry and disposal presents no obvious environmental concerns.     

Rates of molecular vaporization of organic plasticizers

The kinetics of the molecular vaporization process of 21 plasticizers were investigated in detail. By both isothermal and nonisothermal kinetic methods, it was evident that 11 were quite pure single compounds, while 10 were clearly mixtures of compounds. For the single component species internal energies for vaporization and rates of volatilization are listed. The internal energies of vaporization are about one-half or less of values one can estimate from the additive factor method of Small. Thus, solubility parameters based on our experimental values are low by about 30 percent. From this and previous work on linear alkanes, it is concluded that in the molecular vaporization process, the large organic molecules studied evaporate approximately as spheres and hence low values for the energy of vaporization are obtained. Consequently, the difference between our experimental energy and that estimated from solubility parameters is the energy for extending the molecule in a vacuum environment.     

Fast multiplication in VLSI using wave pipelining techniques

Wave pipelining is a design methodology that can increase the clock frequency of digital systems. Also known asmaximum-rate pipelining, it has long been considered a technique for approaching the physical speed limit of a digital circuit. Unlike conventional pipelining, wave pipelining does not require internal clocked elements to increase throughput. The synchronization of internal computations is achieved by balancing inherent RC delays of combinational logic elements, thus allowing circuits to be pipelined at a very fine-grain level. In this article, we describe the design of a 16×16 wave-pipelined multiplier using a 1.0 μm CMOS process. The multiplier is designed using a conventional static CMOS technology. Simulation results show a speedup of about 7× over a nonpipeline implementation.