Eicosanoids in exhaled breath condensates in the assessment of childhood asthma

The value of measurements of eicosanoids in exhaled breath condensate (EBC) for the evaluation of childhood asthma is still inconclusive most likely because of the limited value of the methods used. In this case-control study in 48 asthmatic and 20 healthy children, we aimed to characterize the baseline profile of the inflammatory mediators cysteinyl leukotrienes (cysLTs), 9(alpha)11(beta)PGF(2), PGE(2), PGF(2alpha), 8-isoprostane (8-iso-PGF(2alpha)) within EBC in asthmatic compared with healthy children using new methods. In addition, we investigated their relation to other inflammatory markers. The assessment included collection of EBC, measurement of fractional exhaled nitric oxide (FE(NO)) and evaluation of urinary excretion of leukotriene E(4.) cysLTs were measured directly in EBC by radioimmunoassay and prostanoids were measured using gas chromatography negative-ion chemical ionization mass spectrometry. Only cysLT levels were significantly higher in asthmatic compared with healthy children (p = 0.002). No significant differences in cysLTs were found between steroid naïve and patients receiving inhaled corticosteroids. In contrast, FE(NO) was significantly higher in steroid naïve compared with steroid-treated asthmatic and healthy children (p = 0.04 and 0.024, respectively). The diagnostic accuracy of cysLTs in EBC for asthma was 73.6% for the whole group and 78.2% for steroid-naïve asthmatic children. The accuracy to classify asthmatic for FE(NO) was poor (62.9%) for the whole group, but improved to 79.9% when only steroid-naïve asthmatic children were taken into consideration. cysLTs in EBC is an inflammatory marker which distinguishes asthmatics, as a whole group, from healthy children.

Reactivity to Accelerometer Measurement of Children and Adolescents

PURPOSE: Awareness of being monitored can influence participants' habitual physical activity (PA) behavior. This reactivity effect may threaten the validity of PA assessment. Reports on reactivity when measuring the PA of children and adolescents have been inconsistent. The aim of this study was to investigate whether PA outcomes measured by accelerometer devices differ from measurement day to measurement day and whether the day of the week and the day on which measurement started influence these differences. METHODS: Accelerometer data (counts per minute [cpm]) of children and adolescents (n = 2081) pooled from eight studies in Switzerland with at least 10 h of daily valid recording were investigated for effects of measurement day, day of the week, and start day using mixed linear regression. RESULTS: The first measurement day was the most active day. Counts per minute were significantly higher than on the second to the sixth day, but not on the seventh day. Differences in the age-adjusted means between the first and consecutive days ranged from 23 to 45 cpm (3.6%-7.1%). In preschoolchildren, the differences almost reached 10%. The start day significantly influenced PA outcome measures. CONCLUSIONS: Reactivity to accelerometer measurement of PA is likely to be present to an extent of approximately 5% on the first day and may introduce a relevant bias to accelerometer-based studies. In preschoolchildren, the effects are larger than those in elementary and secondary schoolchildren. As the day of the week and the start day significantly influence PA estimates, researchers should plan for at least one familiarization day in school-age children and randomly assign start days.

Essays on behavioral aspects of the design and disclosure of compensation contracts

This thesis consists of four essays on the design and disclosure of compensation contracts. Essays 1, 2 and 3 focus on behavioral aspects of mandatory compensation disclosure rules and of contract negotiations in agency relationships. The three experimental studies develop psychology- based theory and present results that deviate from standard economic predictions. Furthermore, the results of Essay 1 and 2 also have implications for firms’ discretion in how to communicate their top management’s incentives to the capital market. Essay 4 analyzes the role of fairness perceptions for the evaluation of executive compensation. For this purpose, two surveys targeting representative eligible voters as well as investment professionals were conducted. Essay 1 investigates the role of the detailed ‘Compensation Discussion and Analysis’, which is part of the Security and Exchange Commission’s 2006 regulation, on investors’ evaluations of executive performance. Compensation disclosure complying with this regulation clarifies the relationship between realized reported compensation and the underlying performance measures and their target achievement levels. The experimental findings suggest that the salient presentation of executives’ incentives inherent in the ‘Compensation Discussion and Analysis’ makes investors’ performance evaluations less outcome dependent. Therefore, investors’ judgment and investment decisions might be less affected by noisy environmental factors that drive financial performance. The results also suggest that fairness perceptions of compensation contracts are essential for investors’ performance evaluations in that more transparent disclosure increases the perceived fairness of compensation and the performance evaluation of managers who are not responsible for a bad financial performance. These results have important practical implications as firms might choose to communicate their top management’s incentive compensation more transparently in order to benefit from less volatile expectations about their future performance. Similar to the first experiment, the experiment described in Essay 2 addresses the question of more transparent compensation disclosure. However, other than the first experiment, the second experiment does not analyze the effect of a more salient presentation of contract information but the informational effect of contract information itself. For this purpose, the experiment tests two conditions in which the assessment of the compensation contracts’ incentive compatibility, which determines executive effort, is either possible or not. On the one hand, the results suggest that the quality of investors’ expectations about executive effort is improved, but on the other hand investors might over-adjust their prior expectations about executive effort if being confronted with an unexpected financial performance and under-adjust if the financial performance confirms their prior expectations. Therefore, in the experiment, more transparent compensation disclosure does not lead to more correct overall judgments of executive effort and to even lower processing quality of outcome information. These results add to the literature on disclosure which predominantly advocates more transparency. The findings of the experiment however, identify decreased information processing quality as a relevant disclosure cost category. Firms might therefore carefully evaluate the additional costs and benefits of more transparent compensation disclosure. Together with the results from the experiment in Essay 1, the two experiments on compensation disclosure imply that firms should rather focus on their discretion how to present their compensation disclosure to benefit from investors’ improved fairness perceptions and their spill-over on performance evaluation. Essay 3 studies the behavioral effects of contextual factors in recruitment processes that do not affect the employer’s or the applicant’s bargaining power from a standard economic perspective. In particular, the experiment studies two common characteristics of recruitment processes: Pre-contractual competition among job applicants and job applicants’ non-binding effort announcements as they might be made during job interviews. Despite the standard economic irrelevance of these factors, the experiment develops theory regarding the behavioral effects on employees’ subsequent effort provision and the employers’ contract design choices. The experimental findings largely support the predictions. More specifically, the results suggest that firms can benefit from increased effort and, therefore, may generate higher profits. Further, firms may seize a larger share of the employment relationship’s profit by highlighting the competitive aspects of the recruitment process and by requiring applicants to make announcements about their future effort. Finally, Essay 4 studies the role of fairness perceptions for the public evaluation of executive compensation. Although economic criteria for the design of incentive compensation generally do not make restrictive recommendations with regard to the amount of compensation, fairness perceptions might be relevant from the perspective of firms and standard setters. This is because behavioral theory has identified fairness as an important determinant of individuals’ judgment and decisions. However, although fairness concerns about executive compensation are often stated in the popular media and even in the literature, evidence on the meaning of fairness in the context of executive compensation is scarce and ambiguous. In order to inform practitioners and standard setters whether fairness concerns are exclusive to non-professionals or relevant for investment professionals as well, the two surveys presented in Essay 4 aim to find commonalities in the opinions of representative eligible voters and investments professionals. The results suggest that fairness is an important criterion for both groups. Especially, exposure to risk in the form of the variable compensation share is an important criterion shared by both groups. The higher the assumed variable share, the higher is the compensation amount to be perceived as fair. However, to a large extent, opinions on executive compensation depend on personality characteristics, and to some extent, investment professionals’ perceptions deviate systematically from those of non-professionals. The findings imply that firms might benefit from emphasizing the riskiness of their managers’ variable pay components and, therefore, the findings are also in line with those of Essay 1.

Assessment of the role of LASER-Doppler in the treatment of port-wine stains in infants

BACKGROUND Port-wine stains (PWS) are malformations of capillaries in 0.3% of newborn children. The treatment of choice is by pulsed dye LASER (PDL), and requires several sessions. The efficacy of this treatment is at present evaluated on the basis of clinical inspection and of digital photographs taken throughout the treatment. LASER-Doppler imaging (LDI) is a noninvasive method of imaging the perfusion of the tissues by the microcirculatory system (capillaries). The aim of this paper is to demonstrate that LDI allows a quantitative, numerical evaluation of the efficacy of the PDL treatment of PWS. METHOD The PDL sessions were organized according to the usual scheme, every other month, from September 1, 2012, to September 30, 2013. LDI imaging was performed at the start and at the conclusion of the PDL treatment, and simultaneously on healthy skin in order to obtain reference values. The results evidenced by LDI were analyzed according to the "Wilcoxon signed-rank" test before and after each session, and in the intervals between the three PDL treatment sessions. RESULTS Our prospective study is based on 20 new children. On average, the vascularization of the PWS was reduced by 56% after three laser sessions. Compared with healthy skin, initial vascularization of PWS was 62% higher than that of healthy skin at the start of treatment, and 6% higher after three sessions. During the 2 months between two sessions, vascularization of the capillary network increased by 27%. CONCLUSION This study shows that LDI can demonstrate and measure the efficacy of PDL treatment of PWS in children. The figures obtained when measuring the results by LDI corroborate the clinical assessments and may allow us to refine, and perhaps even modify, our present use of PDL and thus improve the efficacy of the treatment.