The dimensionality of job characteristics: Some neglected issues.

Examined variation in job characteristics across job categories by reanalyzing the original Job Diagnostic Survey database (G. R. Oldham et al, 1979), which includes information on job characteristics for 6,930 employees working on 876 jobs in 56 organizations. Previous research has focused investigation within jobs. A 3-factor solution was found to match best to an a priori structure using principal axis factor anaysis, oblique factor rotations, and a procrustes transformation. This solution retained task identity and job feedback as legitimate job dimensions but detected a 3rd dimension that collapsed skill variety, task significance, and autonomy into a single factor. Additionally, person (age, education) and situational/contextual (position level) variables were found to influence the ability to differentiate among job characteristics. (35 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Selecting for lactation curve and milk yield in dairy cattle

Knowledge of genetic relationships between characteristics of lactation curves and lactation yields is essential for joint selection for both. An equation, yt = atbexp(-ct), was chosen to depict individual lactation curves for 5,927 first lactations by Holsteins in 557 herds in Michigan Dairy Herd Improvement where yt is daily milk yield at day t in lactation, a is yield at time zero, b is ascent to peak, and c is decline after peak. Genetic correlations for 305-day milk yield with initial production (a), ascent to peak (b), descent after peak (c), and peak yield were -.37, .40, 0, and .91. From empirical results from applied selection indexes, selecting for both increase of ascent to peak and peak yield did not decrease 305-day milk substantially. Rankings of sires on these indexes were similar to their rankings on milk yield alone. Attempts to decrease peak yield and increase persistency decreased milk yield greatly.     

Development of a practice-oriented radio-frequency design course

Several decades ago, radiofrequency design was an integral subject in many undergraduate electrical engineering curricula. In recent years, however, practice-oriented courses have given way to theoretical presentations of communication theory. Several years ago, industrial recruiters commented to us about the lack of formal training in radiofrequency design methods in undergraduate curricula. In response, the author has developed a course in this area that is strongly oriented towards design principles and their realization into hardware. The underlying philosophy of this course is described, and a syllabus with associated laboratory exercises is presented     

Electrode-Produced Signal Distortion in Electrophysiological Recording Systems

Although microelectrodes have been in use for many years and there is a wealth of literature concerning their fabrication and application, there is little reported on waveform distortion produced by these electrodes. This paper reports experimental studies conducted to determine the effects of ac electrode polarization in microelectrode recording systems. Electrode materials are examined as well as other system factors such as the use of negative-input-capacitance (NIC) preamplifiers, stimulus isolation units (SIU), and electrode contact integrity.     

The effects of modafinil treatment on neuropsychological and attentional bias performance during 7-day inpatient withdrawal from methamphetamine dependence.

The cognitive benefits of modafinil to patients undergoing 7-day inpatient withdrawal from methamphetamine (MA) dependence were examined as part of a double-blind, randomized, placebo-controlled pilot trial. Recent evidence has identified modafinil-related improvements in treatment outcomes for MA-dependent patients; however, the benefits to cognition function, which is critical to treatment success but known to be impaired, has yet to be examined. The first 20 participants recruited to the study were administered either 200 mg of modafinil (once daily) or placebo, and a neuropsychological test battery (including an MA version of the emotional Stroop task) at admission (n = 17) and discharge (n = 14). Follow-up interviews were conducted at 1-month postdischarge (n = 13). After participant withdrawals (3 in each group), treatment was associated with a significant improvement in immediate verbal memory recall and nonsignificant trend toward improvement on executive function and delayed memory tasks. No benefit was seen for measures of verbal learning, visual memory, processing speed, or verbal fluency. All participants showed a significant attentional bias for MA-related stimuli on the emotional Stroop task. The magnitude of bias predicted both retention in treatment and relapse potential at follow-up but was not significantly ameliorated by modafinil treatment. While nonsignificant, the effect sizes of modafinil-related improvements in executive function and memory were consistent with those found in more robustly powered studies of cognitive benefits in attention-deficit/hyperactivity disorder and schizophrenia, supporting the need for further research. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of selection and training on unit-level performance over time: A latent growth modeling approach.

Surprisingly few data exist concerning whether and how utilization of job-related selection and training procedures affects different aspects of unit or organizational performance over time. The authors used longitudinal data from a large fast-food organization (N = 861 units) to examine how change in use of selection and training relates to change in unit performance. Latent growth modeling analyses revealed significant variation in both the use and the change in use of selection and training across units. Change in selection and training was related to change in 2 proximal unit outcomes: customer service performance and retention. Change in service performance, in turn, was related to change in the more distal outcome of unit financial performance (i.e., profits). Selection and training also affected financial performance, both directly and indirectly (e.g., through service performance). Finally, results of a cross-lagged panel analysis suggested the existence of a reciprocal causal relationship between the utilization of the human resources practices and unit performance. However, there was some evidence to suggest that selection and training may be associated with different causal sequences, such that use of the training procedure appeared to lead to unit performance, whereas unit performance appeared to lead to use of the selection procedure. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The moderating role of subordinate political skill on supervisors' impressions of subordinate ingratiation and ratings of subordinate interpersonal facilitation.

Nearly 2 decades ago, social influence theorists called for a new stream of research that would investigate why and how influence tactics are effective. The present study proposed that political skill affects the style of execution of influence attempts. It utilized balance theory to explain the moderating effect of employee political skill on the relationships between self- and supervisor-reported ingratiation. Additionally, supervisor reports of subordinate ingratiation were hypothesized to be negatively related to supervisor ratings of subordinate interpersonal facilitation. Results from a combined sample of 2 retail service organizations provided evidence that subordinates with high political skill were less likely than those low in political skill to have their demonstrated ingratiation behavior perceived by targets as a manipulative influence attempt. Also, when subordinates were perceived by their supervisors to engage in more ingratiation behavior, the subordinates were rated lower on interpersonal facilitation. Implications of these findings, limitations, and future research directions are provided. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The role of montmorillonite in its catalysis of RNA synthesis

Montmorillonite catalyzes the oligomerization of activated nucleotides to form RNA. However, the mechanism of the montmorillonite catalysis, used as a model for similar prebiotic chemistry, is still not well understood. We have observed that the extent of catalysis depends not only upon the magnitude of the negative charge on the montmorillonite lattice and the number of cations associated with it, but also on the pH at which the reaction is promoted. The isotherm and catalysis studies have been extended to provide binding information and catalytic outcomes over a wide pH range. The optimal binding occurs in the region of maximal oligomer formation. X-ray diffraction studies revealed changes in layer separations of montmorillonite as reaction occurs. The application of the Scherrer equation to the X-ray diffraction data showed differences in domain size. Modeling of the size of the activated nucleotide monomers and the charge on the montmorillonite surface provided an interpretation of how these factors influence adsorption. This research provides a basis for further understanding of the physical processes in the mechanism of this catalysis.