Job Satisfaction as a Reflection of Disposition: A Multiple Source Casual Analysis

Dispositional sources of job satisfaction have been the subject of recent research in the organizational sciences. Problems in much of this research, which limit the conclusions one can draw from the results, are discussed. This study makes a distinction between affective disposition, defined as the tendency to respond generally to the environment in an affect-based manner, and subjective well-being, the level of overall happiness and satisfaction an individual has with his or her life. Affective disposition was hypothesized to lead to subjective well-being, and subjective well-being and job satisfaction were hypothesized to be mutually causative. A causal model was tested employing two different sources of data: self-reports and significant other evaluations. This biangulation of sources of data and estimation of nonrecursive relationships removes some problems often assumed to plague results based on single source data. Results indicated support for the overall hypothesized causal model and supported a dispositional influence on job attitudes. The influences are more complex than past research has suggested

Confirmatory study of time-dependent computed tomographic perfusion thresholds for use in acute ischemic stroke

Background and Purpose: Computed tomographic perfusion (CTP) thresholds associated with follow-up brain infarction may differ by time from symptom onset to imaging and reperfusion. We confirm CTP thresholds over time to imaging and reperfusion in patients with acute ischemic stroke from the HERMES collaboration (Highly Effective Reperfusion Evaluated in Multiple Endovascular Stroke Trials) data. Methods: Patients with occlusion on CT angiography were acutely imaged with CTP. Noncontrast CT and magnetic resonance-diffusion weighted imaging at 24 to 48 hours defined follow-up infarction. Reperfusion was assessed on conventional angiogram. Tmax, cerebral blood flow (CBF), and cerebral blood volume maps were derived from delay-insensitive CTP postprocessing. These parameters were analyzed using receiver operator characteristics to derive optimal thresholds based on time from stroke onset-to-CTP or to reperfusion. ANOVA and linear regression were used to test whether the derived CTP thresholds were different by time. Results: One hundred thirty-seven patients were included. Tmax thresholds of >15.7 s and >15.8 s and absolute CBF thresholds of <8.9 and <7.5 mL·min−1·100 g−1 for gray matter and white matter respectively were associated with infarct if reperfusion was achieved <90 minutes from CTP with stroke onset-to-CTP <180 minutes. The discriminative ability of cerebral blood volume was modest. There were no statistically significant relationships between stroke onset-to-CTP time and Tmax, CBF, and cerebral blood volume thresholds (all P>0.05). A statistically significant relationship was observed between CTP-to-reperfusion time and the optimal thresholds for Tmax (P<0.001) and CBF (P<0.001). Similar but more modest relationship was noted for onset-to-reperfusion time and optimal thresholds for CBF (P≤0.01). Conclusions: CTP thresholds based on stroke onset and imaging time and taking into account time needed for reperfusion may improve infarct prediction in patients with acute ischemic stroke