Group intervention: A way to improve working teams' positive psychological capital.

BACKGROUND: Positive psychological capital is reported to have positive effects on people's well-being and attitudes to their working lives. OBJECTIVE: The objective of this study was to investigate if it is possible to increase the level of positive psychological capital by two group intervention programs. METHODS: The research design was a controlled study with 2 × 2 experimental groups and two control groups. Two of the experimental groups received intervention I (IG I), the other two experimental groups received intervention II (IG II). Assessments were made before and after the intervention programs, with a follow-up at six months post-intervention. Instruments measuring the fundamentals of psychological capital: self-efficacy, hope, optimism, as well as health and job satisfaction were used. RESULTS: The results show that it is possible to increase the level of positive emotions, self-efficacy and job satisfaction of members of a working team by using group intervention methods. The positive changes observed at the end of the program remained six months after the intervention, with the exception of job satisfaction in IG II. It seems that the intervention had a greater influence on those persons who at the start of the study reported a low level of self-enhancement. The results were more pronounced in intervention group I where reinforcement of the resources and positive aspects of the work place environment were provided. CONCLUSIONS: A 10-week group intervention program that focused on learned optimism proved to be successful in increasing levels of self-efficacy and job satisfaction. While improvement was maintained six months post-intervention the small sample size and the attrition rate are limitations. Results are promising and further research is warranted.

The reliability of cardiogenic impedance and correlation with echocardiographic and plethysmographic parameters for predicting CRT time intervals post implantation.

AIMS: Encouraging data have been reported on the use of cardiogenic impedance (CI) in cardiac resynchronization therapy (CRT) optimization. The purposes of this study were to: evaluate the stability of certain CI vectors 24 h postimplantation, study the correlation between these CI signals and selected echocardiographic parameters, and examine the possibility of non-invasive calibration of the patient-specific impedance-based prediction model. METHODS AND RESULTS: Thirteen patients received a CRT-defibrillator device with monitor capability of the dynamic impedance between several electrodes. At implantation, a patient-specific impedance-based prediction model was created for identification of optimal atrioventricular and interventricular (VV) delays and calibrated on invasive measurements of left ventricular contractility (LV dP/dtmax). Simultaneously, non-invasive measurements of LV dP/dtmax and stroke volume (SV) were obtained using a finger plethysmograph. Patients were re-evaluated with echocardiography and new CI measurements the day after implantation. The hemodynamic benefit achieved by optimal VV setting according to the patient-specific impedance-based prediction model at follow-up was not as large as the one obtained at implantation. In a multivariate partial least square regression analysis, a correlation was found between aortic velocity time integral (VTI) and a generic linear combination of CI features (P < 0,005). No correlation was found between the patient-specific impedance-based prediction models and the non-invasive measurements of LV dP/dtmax and SV. CONCLUSION: Cardiogenic impedance signals can be used to optimize CRT settings but seem less feasible as an ambulatory tool since calibration is required. The positive correlation between aortic VTI and CI measurements seems promising, although a larger cohort is required to create an echocardiography-based patient-specific model.

Relationship between intracardiac impedance and left ventricular contractility in patients undergoing cardiac resynchronization therapy.

AIMS: Cardiac resynchronization therapy (CRT) has dramatically improved the symptoms and prognosis of patients with heart failure in large randomized clinical trials. Optimization of device settings may maximize benefit on an individual basis, although the best method for this is not yet established. We evaluated the use of cardiogenic impedance measurements (derived from intracardiac impedance signals) in CRT device optimization, using invasive left ventricular (LV) dP/dtmax as the reference. METHODS AND RESULTS: Seventeen patients underwent invasive haemodynamic assessment using a pressure wire placed in the LV cavity at the time of CRT device implantation. Intracardiac impedance measurements were made at different atrioventricular (AV) and interventricular (VV) delays and compared with LV dP/dtmax. We assessed the performance of patient-specific and generic impedance-based models in predicting acute haemodynamic response to CRT. In two patients, LV catheterization with the pressure wire was unsuccessful and in two patients LV lead delivery was unsuccessful; therefore, data were acquired for 13 out of 17 patients. Left ventricular dP/dtmax was 919±182 mmHg/s at baseline and this increased acutely (by 24%) to 1121±226 mmHg/s as a result of CRT. The patient-specific impedance-based model correctly predicted the optimal haemodynamic response (to within 5% points) for AV and VV delays in 90 and 92% of patients, respectively. CONCLUSION: Cardiogenic impedance measurements are capable of correctly identifying the maximum achievable LV dP/dtmax as measured by invasive haemodynamic assessment. This study suggests that cardiogenic impedance can potentially be used for CRT optimization and may have a role in ambulatory assessment of haemodynamics.

Comparative proteomics of industrial lager yeast reveals differential expression of the cerevisiae and non-cerevisiae parts of their genomes.

The proteomes of three industrial lager beer strains, CMBS33, OG2252 and A15, were analysed under standardised laboratory growth conditions. Protein spots in the 2-DE pattern of the lager strains were subjected to MS/MS to identify protein variants. We found the protein composition of the three lager strains to be qualitatively rather similar, while being substantially different from the Saccharomyces cerevisiae strain BY4742. Database searches using several fully sequenced genomes from the Saccharomyces genera indicated that the non-cerevisiae proteins in the 2-D pattern of lager strains were most closely related to S. bayanus. For many proteins the regulation of the bayanus-like protein and its cerevisiae counterpart varied in a strain-dependent manner, e.g. the bayanus-like form of Tdh3p was roughly eight-fold more abundant than the cerevisiae form in the OG2252 strain. We also found differential regulation of cerevisiae- and bayanus-like proteins during various stress conditions like low temperature growth, and adaptation to high temperatures or high salinity, e.g. for Arg1p, Sti1p and Pdc1p. Our data on the differential regulation of the two genomes in these hybrid strains may have important industrial implications for strain improvement and strain protection.

A statistical model for unwarping of 1-D electrophoresis gels.

A statistical model is proposed which relates density profiles in 1-D electrophoresis gels, such as those produced by pulsed-field gel electrophoresis (PFGE), to databases of profiles of known genotypes. The warp in each gel lane is described by a trend that is linear in its parameters plus a first-order autoregressive process, and density differences are modelled by a mixture of two normal distributions. Maximum likelihood estimates are computed efficiently by a recursive algorithm that alternates between dynamic time warping to align individual lanes and generalised-least-squares regression to ensure that the warp is smooth between lanes. The method, illustrated using PFGE of Escherichia coli O157 strains, automatically unwarps and classifies gel lanes, and facilitates manual identification of new genotypes.

Statistical exploration of variation in quantitative two-dimensional gel electrophoresis data.

Two-dimensional gel electrophoresis is a major technique in global analysis at the protein level. This paper presents an examination of spot volume data from three gel sets with radioactively labeled yeast Saccharomyces cerevisiae proteins. A strong variance versus mean dependence in data was found to be stabilized by applying a shifted logarithmic transformation. However, transformed data showed a remaining substantial variance heterogeneity for different proteins. Furthermore, examination of studentized residuals revealed that transformed data were approximately normally distributed and that there were spatial correlations among the measurement errors in the gel.

Warping two-dimensional electrophoresis gel images to correct for geometric distortions of the spot pattern.

A crucial step in two-dimensional gel based protein expression analysis is to match spots in different gel images that correspond to the same protein. It still requires extensive and time-consuming manual interference, although several semiautomatic techniques exist. Geometric distortion of the protein patterns inherent to the electrophoresis procedure is one of the main causes of these difficulties. An image warping method to reduce this problem is presented. A warping is a function that deforms images by mapping between image domains. The method proceeds in two steps. Firstly, a simple physicochemical model is formulated and applied for warping of each gel image to correct for what might be one of the main causes of the distortions: current leakage across the sides during the second-dimensional electrophoresis. Secondly, the images are automatically aligned by maximizing a penalized likelihood criterion. The method is applied to a set of ten gel images showing the radioactively labeled proteome of yeast Saccharomyces cerevisiae during normal and steady-state saline growth. The improvement in matching when given the warped images instead of the original ones is exemplified by a comparison within a commercially available software.