Methylphenidate, amygdalectomy, and active avoidance performance in the rat.

64 male Sprague-Dawley amygdalectomized and control rats were given 400 active avoidance training trials in a shuttle box. Controls received 0, 4, 8, or 16 mg/kg of methylphenidate throughout acquisition. Amygdalectomized Ss were given the 1st 200 trials without drug, followed by 200 trials with drug. Administration of methylphenidate produced an abrupt and large improvement in performance in the amygdalectomized Ss. One month after acquisition under the drug, retraining without drug revealed a significant retention effect for the 3 amygdaloid-drug groups relative to the nondrug-amygdaloid group. Results indicate that although amygdalectomy impairs the performance of avoidance responses, it does not prevent the learning or retention of such responses. Since methylphendiate appears to act primarily on dopaminergic mechanisms, the possible influence of amygdalectomy on such mechanisms is discussed. (41 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A cooker-extruder for deallergenation of castor bean meal

We present a brief overview on the work Rhee and his colleagues at Texas A&M University have done on the deallergenation of castor bean meal and how a cookerextruder can be used to accomplish it in a commercial plant setting. The extruder used is a high temperature, short residence time cooking extruder that generates frictional heat as it compresses and propels material within the barrel and out through the extrusion dies. Adjustment of water and steam input flow rates allow for selection of moisture levels of cook, and the selection of die size and number of openings allow for adjustment of temperature of cook. An important part of the process is the mixing, blending and absorption of chemical additives into intimate contact with the castor bean meal prior to entry into the extruder. Various methods for doing this are discussed, and a brief overview of what kind of equipment might be incorporated into a deallergenation process line is presented. Presented at the 79th Annual AOCS meeting in May 1988 in Phoenix, Arizona.     

The effect of molybdenum addition on properties of iron aluminides

The effect of the addition of up to 10 pct molybdenum on several metallurgical properties of Fe-28Al (at. pct) to which 1 pct TiB₂ was added for grain refinement has been studied. It was determined that the addition of molybdenum results in a decrease in grain size, an increase in the recrystallization temperature, and an increase in the DO₃ to B2 ordering transformation temperature. The solubility limit of molybdenum in the matrix of the base alloy was found to be about 6 pct. At this concentration, another 1 pct is dissolved in the TiB₂ precipitates. Tensile strengths were increased slightly by adding up to 2 pct Mo, but ductility decreased, even though grain sizes were reduced. The fracture mode in tension did not change with addition of molybdenum up to 2 pct.     

In-orbit testing of TDMA occupied channels

The expected introduction of new TDMA earth-stations in the EUTELSAT network with a lower diameter antenna, together with the need to ensure the high quality of services are the two principal reasons why regular review of the performance trend of TDMA links is becoming so vital. Such a review will allow overall optimization of the EUTELSAT TDMA system by ensuring that the transponders are operated at their specified points, and will make it possible to be prepared in advance in the event of a transponder gain drop to reconfigure the system with no loss of traffic. To implement these tests, EUTELSAT at its IOT facilities near Paris has installed a burst mode saturation analyser' (BMSA) developed by Hollis Electronics Company. The BMSA has been specially designed as a stand-alone test system for testing TDMA channels in a burst mode without interrupting the operational traffic. This paper describes how the BMSA operates and in particular how the system self synchronizes in order to position the BMSA test burst correctly in the frame, and how the burst is allowed to vary in amplitude in order to characterize the channel under test. This paper also discusses how the BMSA is interfaced to the host IOT station and how the tight measurement accuracy in terms of absolute transmit e.i.r.p. and spacecraft IPFD have been met. The paper concludes by comparing results obtained by classical CW test methods with this new burst method. The conclusions also discuss the limitations of the system and suggest possible improvements.     

Congenital anomalies associated with hypospadias

We did a retrospective survey on 200 patients with hypospadias to determine what other congenital anomalies were present. The 56 patients with associated anomalies included 16 who had abnormal excretory urograms and 10 of these 16 patients had defects requiring surgical correction.     

Crossovers in microstrip

The fabrication and characterisation of a crossover structure in microstrip is described. The results indicate the means to achieve either high isolation between physically intersecting signal paths, or a controlled amount of coupling for applications where this is desirable.     

Macromolecular distribution near the limits of density-gradient columns. Some applications to the separation and fractionation of glycoproteins

1. Expressions are derived for the distribution at density-gradient equilibrium of macromolecules whose densities are (a) close to the values characterizing the solution limits or (b) outside the span of the gradient. 2. Density-distribution predicted by the expressions agree with those obtained by rigorous methods. 3. The distribution equations are applied to hypothetical mixtures of proteins and glycoproteins in commonly used density-gradient media to simulate separation and fractionation conditions. 4. It is shown that CsBr, although less efficient than CsCl for fractionation, is nevertheless adequate for most purposes; in analytical experiments it may often have advantages over CsCl. Limitations on the use of LiBr are explored. 5. An expression is derived which allows the variance of the partial specific volume of the macromolecular component to be determined from the variance of the buoyant density. It is shown that the relative resolving powers of different salts is expressed by their values of the quantity (formula: see text). 6. The equations are applied to a well-characterized glycoprotein preparation at equilibrium in CsCl and in Cs2SO4:it is shown that the much wider distribution in CsCl than in Cs2SO4 is explicable in terms of the variance in buoyant density and the solvation properties of the salts. 7. Limitations of the expressions arise when dispersity in density is represented by a low apparent molecular weight; realistic simulations can then only be obtained when the component is fully banded.     

Controlled frustration of total internal reflection by electrophoresis of pigment particles

A model based on geometrical optics has been developed to describe the photometric observations associated with a novel method to control the reflectance of a surface. In this new reflectance modulation approach, electrophoresis of pigment particles is used to absorb light reflected by total internal reflection (TIR). The pigment particles are sufficiently small that they substantially do not scatter light, but rather they modify the effective refractive index at the reflection interface. An incident light ray interacting with this modified effective index is attenuated in a spectrally selective manner. Although frustrated TIR has been understood and used in various applications for some time, in this case it is used to substantially modify the color of the reflected light, which to our knowledge has not been previously reported. A numerical model of the pigment particle distribution has been developed to describe the observations.