When planning fails: Individual differences and error-related brain activity in problem solving.

The neuronal processes underlying correct and erroneous problem solving were studied in strong and weak problem-solvers using functional magnetic resonance imaging (fMRI). During planning, the right dorsolateral prefrontal cortex was activated, and showed a linear relationship with the participants' performance level. A similar pattern emerged in right inferior parietal regions for all trials, and in anterior cingulate cortex for erroneously solved trials only. In the performance phase, when the pre-planned moves had to be executed by means of an fMRI-compatible computer mouse, the right dorsolateral prefrontal cortex was again activated jointly with right parahippocampal cortex, and displayed a similar positive relationship with the participants' performance level. Incorrectly solved problems elicited stronger bilateral prefrontal and left inferior parietal activations than correctly solved trials. For both individual ability and trial-specific performance, our results thus demonstrate the crucial involvement of right prefrontal cortex in efficient visuospatial planning

THE MEDIATING ROLE OF PROCEDURAL JUSTICE IN RESPONSES TO PROMOTION DECISIONS

ABSTRACT This study used structural equations modeling to examine the mediating role of procedural justice in the relationships between promotion decisions and organizational commitment and between promotion decisions and intent to leave the organization. 156 managers and executives in Italian subsidiaries of two large multinational organizations in the chemical industry were surveyed about their career history within the organization and their reactions to promotion decisions over an 8-year period. The results showed that promotion decisions influenced feelings of organizational commitment through perceptions of procedural justice in promotion decision-making processes. The theoretical and practical implications of the study s findings are discussed. Keyword procedural justice- promotion decisions- career

Left Ventricular Function After Prolonged Exercise in Equine Endurance Athletes

BACKGROUND: Prolonged exercise in human athletes is associated with transient impairment of left ventricular (LV) function, known as cardiac fatigue. Cardiac effects of prolonged exercise in horses remain unknown. OBJECTIVES: To investigate the effects of prolonged exercise on LV systolic and diastolic function in horses. ANIMALS: Twenty-six horses competing in 120-160 km endurance rides. METHODS: Cross-sectional field study. Echocardiography was performed before and after rides, and the following morning, and included two-dimensional echocardiography, anatomical M-mode, pulsed-wave tissue Doppler imaging, and two-dimensional speckle tracking. Correlation between echocardiographic variables and cardiac troponin I was evaluated. RESULTS: Early diastolic myocardial velocities decreased significantly in longitudinal (baseline: -17.4 ± 2.4cm/s; end of ride: -15.8 ± 3.2cm/s (P = .013); morning after: -15.4 ± 3.0cm/s (P = .0033)) and radial directions (-32.8 ± 3.4cm/s; -28.1 ± 5.8cm/s (P < .001); -26.4 ± 5.5cm/s (P < .001)). Early diastolic strain rates decreased significantly in longitudinal (1.58 ± 0.27s(-1) ; 1.45 ± 0.26s(-1) (P = .036); 1.41 ± 0.25s(-1) (P = .013)) and circumferential directions (2.43 ± 0.29s(-1) ; 1.96 ± 0.46s(-1) (P < .001); 2.11 ± 0.32s(-1) (P < .001)). Systolic variables showed ambiguous results. No correlations with serum cardiac troponin I concentrations were evident. CONCLUSIONS AND CLINICAL IMPORTANCE: Prolonged exercise in horses is associated with impaired LV diastolic function. Reduced ventricular filling persisted for 7-21 hours despite normalization of biochemical indicators of hydration status, indicating that the observed changes were not entirely related to altered preload conditions. The clinical relevance of cardiac fatigue in horses remains uncertain

A DFDL UV picosecond fluorescence spectrometer: Application to aqueous solutions of peptides and nucleotide dye conjugates

Using a new type of fluorescence lifetime spectrometer, the time resolution of single shot fluorescence detection is improved by two orders of magnitude. The spectrometer is based on a streak camera and an excimer laser pumped distributed feedback dye laser (DFDL) providing UV pulses of 50 μJ and 15 ps FWHM, corresponding to a peak power of ∼ 5 · 106 W in the ultraviolet. —This spectrometer is used to investigate the fluorescence decay of peptides containing a tyrosine as the single fluorophore. Peptides with tyrosine at the N-terminus reveal a biexponential decay, while peptides with C-terminal tyrosine are mainly monoexponential. This difference can be explained by the relative orientation of the fluorescing phenol ring and the quenching peptide bond. —The fluorescence decay of a number of peptides with tyrosine in a non terminal position can be described by two lifetimes, 2.3 · 0.1 ns and 380 ± 70 ps, where the percentage of the long lifetime increases to up to 100% when the rotational flexibility of the peptide chain decreases, either due to increasing weight of the chain or due to formation of an H-bridge. —Similar processes seem to be relevant for the fluorescence of the dye coumarin 120 coupled to nucleotides. The fluorescence lifetime of such molecules is significantly different, so that the four DNA nucleotides can be identified on the basis of the fluorescence decay of the attached dye

Echocardiographic assessment of left ventricular function in healthy horses and in horses with heart disease using pulsed-wave tissue doppler imaging

BACKGROUND: Assessment of left ventricular (LV) function by tissue Doppler imaging (TDI) is not well established in horses with heart disease. OBJECTIVES: To describe the use of pulsed-wave (PW) TDI for the assessment of LV function, establish reference intervals, investigate effects of mitral regurgitation (MR), aortic regurgitation (AR), and primary myocardial disease (MD), and provide proof of concept for the use of PW TDI in Warmblood horses with heart disease. ANIMALS: Thirty healthy horses, 38 horses with MR, 25 with AR, 8 with MD. METHODS: Echocardiograms were retrospectively analyzed. Reference intervals were calculated. PW TDI indices of healthy horses and horses with MR, AR, and MD were compared by one-way ANOVA and Dunnett's test. RESULTS: A complete set of PW TDI variables could be obtained in 94 of 101 horses. Variables corresponding to isovolumic intervals were most difficult to measure. Valvular regurgitation influenced variables describing isovolumic contraction and ejection. Horses with MD had significantly shortened ETm (-118.5 [-154.1 to -82.9] ms; mean difference [95% CI of difference of means]), increased PEPm /ETm (0.11 [0.05 to 0.17]), prolonged IMPm (0.28 [0.18 to 0.37]), increased S1 (8.9 [5.2 to 12.6] cm/s), and decreased E1 (-2.6 [-4.7 to -0.5] cm/s), Em (-14.2 [-19.9 to -8.5] cm/s), and Em /Am ratio (-1.6 [-2.6 to -0.6]). CONCLUSIONS AND CLINICAL IMPORTANCE: Pulsed-wave TDI might be useful for detection of LV dysfunction in horses with primary MD. The clinical value of TDI in horses with MR and AR remains uncertain