Autofluorescence and green fluorescent protein-derived fluorescence in Listeria innocua

Fluorescent L. innocua M1 was generated by transformation with plasmid SB2019 carrying gfp3. The transformed organism exhibited 2 h longer lag phase than the parental strain. The transformation and gfp3 expression did not affect the growth rates (0.49 ± 0.02 and 0.47 ± 0.05 h⁻¹) and the maximum optical densities (1.02 ± 0.01 and 0.90 ± 0.06) of the parental or the transformed strains. The transformation of L. innocua M1 with pSB2019 resulted in cell-concentration related fluorescence which was detectable from washed cells but not in growth media. Statistical discrimination between GFP3-driven and background fluorescence signals of transformed and parental strains occurred at cell optical densities of 0.1 and above which was partially due to a relatively high endogenous autofluorescence. Although the gfp-transformed L. innocua M1 developed in this study has the potential to be a marker organism for monitoring Listeria spp. responses in mixed cultures, more work is needed to optimize the GFP-based fluorescent signal.     

Pre- and poststimulus activation of response channels: A psychophysiological analysis.

To examine mechanisms of response activation, we asked subjects to respond differentially to the central letter of one of four arrays—{hhhhh}, {sshss}, {sssss}, and {hhshh}—and measured event-related brain potentials (ERPs) and electromyographic activity (EMG). For very fast responses, accuracy was at chance level for all arrays, suggesting that subjects were guessing. For intermediate latency responses, accuracy was above chance if the noise was compatible with the targets and below chance if it was incompatible, suggesting that these responses were based on partial stimulus analysis. For slow responses, accuracy was above chance for all arrays, suggesting that these responses were based on complete stimulus analysis. The occurrence and accuracy of fast responses could be predicted by examining motor potentials preceding the presentation of the array. Measures of the motor potentials in the period following the presentation of the array suggested that partial analysis of stimulus information could activate responses and that the level of response activation at the time of the EMG response was constant for trials with different response latencies. The data are discussed in terms of a response channel conception. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Fault identification using a finite state machine model withunreliable partially observed data sequences

The problem of minimum cost identification of a finite state machine (FSM) using a trace of its event history is addressed. The motivation is fault identification in communication systems, although other applications are possible as well. The event history used for the identification is partially observed, i.e., it is known to be a member of a regular language. Any string which belongs in this regular language is a possible trace of the FSM's event history. Furthermore, the event history is assumed to be corrupted with deletions, additions, and changes of symbols. The FSM to be estimated is related to a known FSM by performing an unknown number of additions and changes of arcs. An identification algorithm based on a fast algorithm that can correct corrupted data strings generated by a known finite state machine is developed. Examples of the method are provided, including one based on the IEEE 802.2 logical link control protocol     

Does part-set cuing test for memory organization? Evidence from reconstructions of chess positions.

Two studies with 12 casual and 12 tournament chess players (undergraduates) examined the relationship between part-set cuing and the organization of memory. After studying partly played chess games, Ss tried to reconstruct the board positions from memory, starting sometimes with a clear board and sometimes with half of the pieces already in place. For neither casual players (Exp I) nor tournament players (Exp II) did the placed pieces improve positioning of the remaining pieces. This result parallels the standard finding of no facilitation through part-set cuing in the recall of word lists and sheds some light on whether this finding is due to memory for word lists not being organized or to the failure of the part-set cuing procedure to detect its organization. To the extent that one can be more sure of memory for chess positions being organized than one can be of memory for word lists being organized, the present findings suggest that the part-set cuing procedure does not test for memory organization. (French abstract) (15 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Commitment to company and union: Parallel models.

Parallel models of commitment to company and commitment to union were tested with 16 employees of the transportation department of a unionized metropolitan newspaper. In addition to the commitment measures, Ss completed segments of the Job Diagnostic Survey and instruments assessing job stress, perceived pay equity, and social involvement. Results indicate that an organizational-commitment model is less successful in predicting union commitment than company commitment. The most striking divergence occurred with respect to personal characteristics, which were significantly correlated with company commitment and were unrelated to union commitment. However, the work-experience variables of supervisory relations and social involvement were significantly correlated with both types of commitment. Results have implications for the concept of "dual loyalty," which appears to be explained by day-to-day work experiences. (14 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Conditioned emotional distress in women receiving chemotherapy for breast cancer.

This study investigated whether women undergoing outpatient chemotherapy for breast cancer can develop classically conditioned emotional distress. Women scheduled to begin chemotherapy were randomly assigned either to an experimental group (exposed to a distinctive stimulus before each chemotherapy infusion) or a control group. After repeated infusions of chemotherapy, patients' responses to the distinctive stimulus were assessed in a location not associated with chemotherapy administration. At the test trial, experimental group patients showed evidence of increased emotional distress (self-reported on a visual analog scale) after the presentation of the distinctive stimulus, whereas control group patients did not. Post hoc analyses indicated that these increases in distress were not secondary to other conditioned responses (e.g., nausea, taste aversion). Thus, results supported the hypothesis that the pairing of a distinctive stimulus with chemotherapy would result in the development of a conditioned emotional response. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Mode-locking and chaos in a model of two coupled thermostatically controlled radiators

The paper examines a variety of nonlinear dynamic phenomena arising from the interaction between two thermostatically controlled radiators. Each system operates as a delayed, nonlinear control system and performs self-sustained opening and closing cycles when the slope of the regulator characteristics exceeds a critical value. The coupling is caused by heat exchange between the heated air volumes. As the sensitivity of one of the thermostats is changed, a devil's staircase of frequency-locked oscillations develops. For higher coupling strengths, mode-converting bifurcations, simultaneous periodic solutions and deterministic chaos can be observed.     

A comparison of rotational representations in structure and motionestimation for manoeuvring objects

Alternative methods are examined for estimating motion and structure of objects undergoing smooth maneuvers through measurements of feature positions in long, multiple-camera image sequences. Performance of extended Kalman filters are compared for Euler angle-axis, roll-pitch-yaw, and quaternion parameterizations of rotational motion. The angle-axis method was found to give the best overall performance with a computationally efficient implementation.