Attentional versus motor inhibition in adults with attention-deficit/hyperactivity disorder.

Faulty inhibition is theorized to be a central feature in attention-deficit/hyperactivity disorder (ADHD), but it remains unclear whether inhibitory impairments encompass both motoric and attentional domains. Further, characterization of inhibitory deficits in adults with ADHD is needed. We experimentally assessed adults who met diagnostic criteria for ADHD and a subgroup who had partially remitted. Diagnostic and Statistical Manual of Mental Disorders (4th ed.; American Psychiatric Association, 1994) subtype effects were also examined. Motoric inhibition was assessed with the antisaccade task, and attentional inhibition was assessed with the attentional blink (AB) task. Antisaccade results replicated prior findings of extended latencies and increased anticipatory saccades in ADHD. Errors, however, appeared to be epiphenomenal to ADHD as they were absent when symptoms had partially remitted. Anticipatory saccades appeared as potential core problems that remained even when symptoms had improved. Differential response patterns were found for predominantly inattentive and combined subtypes, with the latter showing increasing anticipatory movements with increasing fixation time. In the AB task, ADHD groups committed more errors but showed no convincing evidence of an abnormal blink. These results demonstrate clear effects on motoric inhibition but not attentional inhibition in adults with ADHD. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Detection of guaiacol produced by Alicyclobacillus acidoterrestris in apple juice by sensory and chromatographic analyses, and comparison with spore and vegetative cell populations

Spoilage of fruit juice by Alicyclobacillus acidoterrestris is characterized by a distinct medicinal or antiseptic off odor attributed to guaiacol, a metabolic by product of the bacterium. Detection of low populations of A. acidoterrestris that would precede sensory detection of guaiacol would enable juice processors to select appropriate processing and storage conditions that would minimize or eliminate spoilage. The objective of this study was to determine the recognition threshold of guaiacol in apple juice by sensory analysis and the population of A. acidoterrestris and incubation time at 21 and 37 degrees C necessary for chemical detection of guaiacol. Commercially sterilized apple juice (pH 3.54 +/- 0.04, 11.3 +/- 0.3 degrees Brix) was inoculated with a five-strain mixture of A. acidoterrestris spores (2.98 log10 CFU/ml) and stored at 21 or 37 degrees C for up to 61 days. Using an experienced sensory panel and the forced-choice ascending concentration method of limits, the best estimate threshold (BET) for recognition of guaiacol added to uninoculated apple juice was 2.23 ppb. Numbers of A. acidoterrestris spores and cells in inoculated juice remained constant during the 61-day storage period; however, the panel detected (P < or = 0.01) guaiacol in juice stored at 37 degrees C within 8 days. At three of four sampling times ranging from 13 to 61 days at which the sensory panel detected (P < or = 0.001) guaiacol, concentrations of 8.1 to 11.4 ppb were detected by chromatographic analysis. The panel detected (P < or = 0.1 to P < or = 0.01) guaiacol in five samples stored at 21 to 37 degrees C for 8 to 61 days in which the compound was not detected by chromatographic analyses. It appears that guaiacol content in apple juice inoculated with A. acidoterrestris is not always correlated with numbers of cells, and the limit of sensitivity of chromatographic quantitation of the compound is higher than the BET.     

Thermo-optic designs for electromagnetic-field probes formicrowaves and millimeter waves

The development of an electromagnetic-field probe for microwave and millimeter-wave frequencies is reported. The probe uses an optically sensed thermometer to measure the heating of a resistive element in an electromagnetic field. The response is calculated for several different configurations of the resistive element, and two optimal designs are chosen. Measurements on experimental probes of these designs are presented. One of the designs displays a flat frequency response above 30 GHz and a sensitivity of 38 V/m. Improvements in the design are identified that should significantly increase the sensitivity and improve the low-frequency response     

UCN-01 abrogates G2 arrest through a Cdc2-dependent pathway that is associated with inactivation of the Wee1Hu kinase and activation of the Cdc25C phosphatase

We have previously demonstrated that UCN-01, a potent protein kinase inhibitor currently in phase I clinical trials for cancer treatment, abrogates G2 arrest following DNA damage. Here we used murine FT210 cells, which contain temperature-sensitive Cdc2 mutations, to determine if UCN-01 abrogates G2 arrest through a Cdc2-dependent pathway. We report that UCN-01 cannot induce mitosis in DNA-damaged FT210 cells at the non-permissive temperature for Cdc2 function. Failure to abrogate G2 arrest was not due to UCN-01-inactivation at the elevated temperature because parental FM3A cells, which have wild-type Cdc2, were sensitive to UCN-01-induced G2 checkpoint abrogation. Having established that UCN-01 acted through Cdc2, we next assessed UCN-01's effect on the Cdc2-inhibitory kinase, Wee1Hu, and the Cdc2-activating phosphatase, Cdc25C. We found that Wee1Hu was indeed inactivated in UCN-01-treated cells, possibly just prior to Cdc2 activation and entry of DNA-damaged cells into mitosis. This inhibition appeared, however, to be a consequence of a further upstream action since in vitro studies revealed purified Wee1Hu was relatively resistant to UCN-01-inhibition. Consistent with such an upstream action, UCN-01 also promoted the hyperphosphorylation (activation) of Cdc25C in DNA-damaged cells. Our results suggest that UCN-01 abrogates G2 checkpoint function through inhibition of a kinase residing upstream of Cdc2, Wee1Hu, and Cdc25C, and that changes observed in these mitotic regulators are downstream consequences of UCN-01's actions.     

Fimbria-fornix cut affects spontaneous activity, two-way avoidance and delayed non matching to sample, but not latent inhibition

Latent inhibition (LI) consists of a decrement in conditioning to a stimulus as a result of its prior nonreinforced preexposure. Based on evidence pointing to the involvement of the hippocampus and the nucleus accumbens (NAC) in LI disruption, it has been proposed that LI depends on the integrity of the subicular input to the NAC. Since fibers originating in the subiculum and destined for the NAC run through the fimbria-fornix, we assessed the effects of fimbria-fornix lesion, made using a knife cut, on LI. In addition, we assessed the effects of the fimbria-fornix cut in three tests known to be sensitive to lesions to the hippocampal region, namely, spontaneous activity, two-way active avoidance and delayed-non-matching-to-sample. In accord with previously documented effects of lesions to the hippocampus and related structures, the fimbria-fornix cut increased spontaneous activity (Experiment 1), facilitated the acquisition of two-way active avoidance (Experiment 3), and produced a delay-dependent deficit in the delayed-non-match-to-sample task (Experiment 4), demonstrating that it disrupted hippocampal functioning. In contrast, LI remained unaffected by the fimbria-fornix cut (Experiment 2), indicating that disruption of subicular input to the NAC is not responsible for the attenuation of LI following non-selective hippocampal lesions. The implications of these results for the neural circuitry of LI are discussed.     

An empirical analysis of the computerization of interactive software evaluation systems

This research studies factor analysis of traditional survey- questionnaires for interactive software evaluation in order to construct a Principal Factor Conversion Function (PFCF). Such a PFCF may be used in several ways: first, for exploratory purposes, to discover the principal factors of the traditional questionnaire; second to test the potential of data reduction within significant loss of information; and third to compare the traditional manual evaluation to a condensed computerized interactive software evaluation. A CAI system was used as the software to be evaluated in this research.