Automated Test Apparatus Research Articles

Automated test apparatus for bench-testing the magnetic field homogeneity of NMR transceiver coils

We describe an automated hands-off bench testing method for measuring the magnetic field profile of transceiver coils for nuclear magnetic resonance (NMR). The scattering parameter (S-parameter) data is measured using a portable network analyzer, and the results are automatically exported to a computer for plotting and viewing. This assay dramatically reduces the time needed to measure the magnetic field (B1) homogeneity profile of a transceiver coil while also improving accuracy relative to manual operation. Here, we demonstrate the method on a saddle coil of a solution-state NMR probe in comparison to profiles obtained using NMR spectroscopy measurements. We also measure the axial homogeneity of a variable-pitch solenoid.

Automated Testing Apparatus for Ceramic Membrane Filtration of High-Strength Industrial Wastewater

Automated Testing Apparatus for Ceramic Membrane Filtration of High-Strength Industrial Wastewater

2-Chloro-3,7,8-tribromodibenzofuran as a new environmental pollutant inducing atypical ultrasonic vocalization in infant mice.

Epidemiological and experimental studies indicate that maternal exposure to environmental pollutants impairs the cognitive and motor functions of offspring in humans and laboratory animals. Infant ultrasonic vocalizations (USVs), the communicative behavior of pups toward caregivers, are impaired in rodent models of neurodevelopmental disorders, suggesting a useful method to evaluate the developmental neurotoxicity of environmental pollutants. Therefore, we investigated USVs emitted by mouse pups of dams exposed to 2-chloro-3,7,8-tribromodibenzofuran (TeXDF) and 1,2,3,7,8-pentabromodibenzofuran (PeBDF), which are detected in the actual environment. The USV duration and number in the pups born to dams administered with TeXDF 40μg/kg body weight (b.w.), but not 8μg/kg b.w., on gestational day (GD) 12.5, were significantly lower than those in the corresponding pups on postnatal days 3-9. Conversely, there was no statistical change in the USVs emitted by the pups of dams administered with PeBDF 35 or 175μg/kg b.w. on GD 12.5. To examine whether maternal exposure leads to behavioral impairments in adulthood, we analyzed exploratory behaviors in a novel environment using IntelliCage, a fully automated testing apparatus for group-housed mice. Neither TeXDF nor PeBDF exposure induced significant differences in offspring exploration. Considered together, our findings revealed that TeXDF induces atypical USV emission in infant mice, suggesting the importance of further studies on the risk assessment of mixed brominated/chlorinated dibenzo-p-dioxins and dibenzofurans.

Consistent within-group covariance of septal and temporal hippocampal neurogenesis with behavioral phenotypes for exploration and memory retention across wild and laboratory small rodents

Striking differences in the septo-temporal distribution of neurogenesis are found in small rodents. Here, we assessed the association of adult hippocampal neurogenesis with behavioral responses to novelty, temporal and spatial sequence and reversal learning in wild, wild-derived and laboratory rodents using an automated testing apparatus, the IntelliCage. Behaviorally, DBA/2 and wild-derived house mice were quickest to explore a novel environment, wild wood mice and bank voles were slowest, and C57BL/6 intermediate. Rule learning (temporal and spatial) was fastest in wood mice and bank voles, while DBA/2 and house mice performed poorer. C57BL/6 performed similar to the house mice in the temporal task and similar to wild rodents in the spatial task. Using the number of DCX-positive neurons and proliferating, Ki67-positive cells in the septal, intermediate and temporal hippocampus as a proxy, an ANCOVA was used to test for within-group relations between neurogenesis and behavior. We found that higher numbers of DCX-positive cells in the temporal hippocampus were associated with an increased latency and a lower frequency to explore a novel environment. Temporal and spatial sequence learning was not associated with neurogenesis. In the spatial reversal task however, animals with higher septal neurogenesis showed a persevering phenotype and slower re-learning. Our findings provide strong evidence of septo-temporally segregated neurogenesis effects on behavior across five rodent strains and species. While temporal neurogenesis covaries with behavioral responses to novelty, septal neurogenesis relates to perseverance of a successfully learned spatial rule. Importantly, these associations were independent of species or strain and can be found in both wild and domesticated rodents.

A Cross-Laboratory Investigation of Timing Endophenotypes in Mouse Behavior

Phenotyping behavioral and cognitive processes is a critical practice in mouse research and reliable phenotypic assessment is an essential component of building well-defined links between genes and behavioral/cognitive functions. The success of behavioral screens in neurobehavioral mouse genetics depends on the identification of reliable, reproducible, and high-throughput behavioral/cognitive measures from individual animals irrespective of the differences in opinions regarding how to tackle phenotyping in different behavioral domains. Furthermore, reliable behavioral assays must be resistant to inevitable environmental differences across laboratories since protocols can be replicated but not all the environmental conditions. Here we present a cross-laboratory study of interval timing behaviors in mice. Two classically used mouse inbred substrains, C57BL/6J and C57BL/6N, were studied over several days in home-cages containing automated testing apparatus. Remarkably, all timing measures in mouse performance showed a robust reproducibility across centers and even small differences between the two substrains were comparable across laboratories. Moreover, we have observed a consistent increase in error rate during the light phase of the light–dark cycle, which suggests that mouse performance during this phase is compromised by a possible sleep inertia-like effect. Overall, our study demonstrates that analysis of mouse timing behavior can lead to robust and reliable endophenotypes in mouse behavioral genetic studies.

Computational and experimental study of proximal flow in ventricular catheters. Technical note.

The treatment of hydrocephalus with shunt insertion is fraught with high failure rates. Evidence indicates that the proximal holes in a catheter are the primary sites of blockage. The authors have studied ventricular catheter designs by using computational fluid dynamics (CFD), two-dimensional water table experiments, and a three-dimensional (3D) automated testing apparatus together with an actual catheter. With the CFD model, the authors calculated that 58% of the total fluid mass flows into the catheter's most proximal holes and that greater than 80% flows into the two most proximal sets of holes within an eight-hole catheter. In fact, most of the holes in the catheters were ineffective. These findings were experimentally verified using two completely different methodologies: a water table model of a shunt catheter and a 3D automated testing apparatus with an actual catheter to visualize flow patterns with the aid of ink. Because the majority of flow enters the catheter's most proximal holes, blockages typically occur at this position, and unlike blockages at distal holes, occlusion of proximal holes results in complete catheter failure. Given this finding, new designs that incorporated varying hole pattern distributions and size dimensions of the ventricular catheter were conceived and tested using two models. These changes in the geometrical features significantly changed the entering mass flow rate distribution. In conclusion, new designs in proximal ventricular catheters with variable hole diameters along the catheter tip allowed fluid to enter the catheter more uniformly along its length, thereby reducing the probability of its becoming occluded.

Removal of the amygdala plus subjacent cortex disrupts the retention of both intramodal and crossmodal associative memories in monkeys.

Naive rhesus monkeys (Macaca mulatta) were trained preoperatively in an automated test apparatus on an auditory-visual (crossmodal) conditional task or on a visual-visual (intramodal) conditional task that involved learning a fixed set of stimulus-stimulus associations or paired associates. After having learned their respective tasks, each monkey received bilateral removal of the amygdala plus subjacent cortex. The 2 experimental groups showed equally poor retention of the stimulus-stimulus associations and subsequently relearned their respective crossmodal and intramodal associations at the same rate. These data argue against the idea that the amygdala is specialized for crossmodal associations. Instead, the data indicate that the amygdala or its underlying cortex, or both, play a more generalized role in stimulus-stimulus associative memory.

Cognitive changes during normal aging in monkeys assessed with an automated test apparatus

Cognitive changes during normal aging in monkeys assessed with an automated test apparatus

Picture recognition vs. picture discrimination learning in monkeys with medial temporal removals

Three monkeys with complete ablations of temporal-lobe limbic structures and three unoperated controls were compared in an automated testing apparatus for their ability to remember pictures presented between 1 and 180 seconds previously, as well as to learn picture discriminations in which successive trials with a given pair were separated by either 20 seconds or 24 hours. The operated animals were not impaired in picture discrimination learning under either condition and they were not impaired in picture recognition memory up to about 10 seconds. At 10 seconds and beyond, however, the operated animals showed rapid deterioration of picture memory. The results demonstrate that the limbic system's selective contribution to learning and retention uncovered initially with objects applies equally to pictures, this contribution being essential for recognition memory but not for discrimination habits. The results demonstrate further that, as in humans, temporal-lobe limbic structures are essential for recognition only when the retention test exceeds the immediate memory span of a few seconds.

4736374 Automated test apparatus for use with multiple equipment

4736374 Automated test apparatus for use with multiple equipment

Antagonistic behavioral effects of calcitonin and amphetamine in the rat

Using an automated testing apparatus, the hypermotility induced by amphetamine had previously been found to be inhibited by intracerebroventricular (ICV) administration of salmon calcitonin (CT). The present study used a computer-supported direct observational method to characterize further the interactions of CT and amphetamine. After treatment with amphetamine (1.5 mg/kg, IP), the incidence of rearing, nose poking, and locomotion was reduced in rats that were pretreated with 85 pmol salmon CT ICV; the incidence of sniffing and grooming remained unchanged. CT-induced dyskinesia, a unique consequence of central CT treatment, was attenuated but not abolished by administration of amphetamine. These results support the premise that a compound with receptor recognition characteristics similar to those of salmon CT may act as neurotransmitter-modulator in the central nervous system.

Automatic near-threshold fatigue crack growth rate measurements at liquid helium temperature

The development of a fully automated test apparatus for near-threshold fatigue crack growth rate measurements in a liquid helium environment is described, and some initial results for AISI 300 series stainless steels are presented. The experimental apparatus consists of a servohydraulic test machine and a cryostat, complete with a minicomputer, a programmable arbituary waveform generator, a programmable digital oscilloscope and a fully automatic liquid helium refill system. The technique uses 6.4 mm thick compact specimens subjected to systematically decreasing loads, with 24 h operation at 40 Hz, the crack growth being continuously monitored by specimen compliance measurements. The results presented in this study include da/ dN vs ΔK curves and threshold fatigue stress intensity factors, ΔK th , at 4 K for AISI 304L, 304LN and 316 stainless steels. The near-threshold fatigue behaviours of these materials are similar, and the fatigue crack growth rate trends at intermediate ΔK levels nearly agree with published results.

Discrimination-reversal learning of normal and septal rats.

The purpose of this study was to assess the complex learning skills of normal and septal rats using Rumbaugh's discrimination-reversal task. Transfer Index testing was carried out by using the automated test apparatus, stimulus items, and procedure described by Rumbaugh, et al. in 1972. Even though there were no significant differences between normal and septal rats, all rodents tested showed above chance performance on the transfer index task ( M = .82, range was .67 to .92). An analysis of errors in reversal indicated that the rats had more errors involving a single wrong response and fewer strings of consecutive errors. Also, the occurrence of “win-stay” and “lose-shift” response strategies for the four rats with the highest percentages correct on the second reversal trial (High Group) were compared with those of the four rats who had the lowest percentages correct on the second reversal trial (Low Group). The animals in the High Group demonstrated both “win-stay” and “lose-shift” response strategies, while those rats in the Low Group showed only a “lose-stay” response strategy. The rodents in the Low and High groups did not differ from each other in the use of a “win-shift” response strategy. These results suggest that rats can use rule or association learning to solve discrimination-reversal problems.

A system for behavioral evaluation of the visual capacities of cats

An automated testing apparatus for evaluating the visual capacities of cats is described. It features ease of training, reliability, and flexibility in the type of stimuli that can be presented. For presentation of complex visual stimuli, a closed circuit television display system has been devised that is compatible with the behavioral testing apparatus.

Variables affecting the wetting of tinplate by Sn-Pb solders

An automated test apparatus has been developed which, for any specific system of tinplate-fluxsolder, enables a very rapid and reproducible direct measurement of four solder wettability parameters;viz., time for initial wetting, wetting rate, equilibrium wetting force, and time to reach this force. These parameters have been measured to determine the effects of the following tinplate soldering variables: three different mild rosin fluxes, solder temperature and composition, tinplate thickness, tin and alloy coating thickness, surface roughness, tin oxide films deposited electrochemically and by baking, and chrome oxide passivating films. In general, wettability data concur with capillary rise measurements but have the advantage of being obtained more rapidly, of being more sensitive to surface state variables, and of being more reproducible. Of the four measured parameters, wetting rate is most sensitive to tinplate surface state and equilibrium force is the best indicator of solder spread.

Orienting behavior and discriminative proficiency of monkeys

Seventeen test-sophisticated rhesus monkeys were trained to discriminate between pairs of visual metric patterns in an automated apparatus (Wisconsin Automated Test Apparatus, WATA) and the Wisconsin General Test Apparatus (WGTA). Regardless of the previous test experience of the animals (WATA or WGTA) their performance in the WATA was consistently superior to that obtained in the WGTA. This finding was interpretated to be the result of design features in the WATA that tended to insure appropriate orienting behavior on each trial.

An assessment of automatically dispensed primate reinforcers.

The use of automated test apparatus has posed a special problem in providing food reinforcement. These reinforcers must satisfy various criteria: reliability of delivery by an automatic feeder; some uniformity of amount and shape; economic availability; and consistency of high-preference value. These experiments are an attempt to determine the relative preference values of a number of reinforcers which, to some extent, meet the other criteria.