9. The corrections do not have any influence on our conclusions. Table 1 Dropouts and non respondents   N % Randomly selected from Danish Central Office of Civil Registration 8,000    Excluded from the study (12 had emigrated, 50 had unknown address, 62 were mentally handicapped, 37 were aboard for a longer period, 2 were dead and 3 people were also in first DPWES* PLX-4720 nmr cohort) 166   Total sample 7,834 100  No response 3,049 38.9  Invalid respond; too many missing values or inconsistent data for gender

and day of birth compared to the Civil Registration data 53 0.7 Valid response 4,732 60.4  Excluded; not wage earner 1,215    Excluded; missing value for the bullying question 88   Final population for the study 3,429   * Danish Psychosocial Work Environment Study In addition to the original authors, we would also like to include Helene Feveile in the list of authors of the erratum, so that Roscovitine supplier the list of authors is: Adriana Ortega, Annie Høgh, Jan Hyld Pejtersen, Helene Feveile and Ole Olsen.”
“Introduction The subjective symptom fatigue is a major source of health care utilization and it is one of the most widespread symptoms in the general population (Lloyd 1998). Prolonged fatigue forms the basis of, among others, chronic fatigue syndrome (Lloyd 1998). Reasonable evidence currently exists to justify the assumption that psychological

factors (e.g. chronic stress), mediated by biological factors, are involved in the development of many somatic complaints and disorders (Papousek et al. 2002). This apparently applies to prolonged fatigue as well. Research indicates that chronic fatigue syndrome is frequently preceded by negative life events or chronic stressors, sometimes in combination with viral infections (Theorell et al. 1999; van Houdenhoven et al. 2001; Ware and Kleinman

3-mercaptopyruvate sulfurtransferase 1992). Chronic stress may in some cases, when over activation of the stress systems is sustained, result in long-term negative effects on biological factors (e.g. the autonomic nervous system) (McEwen 1998; Clements and Turpin 2000; Cohen et al. 2000). The direct relationship between imbalances in the autonomic nervous system and prolonged fatigue has also been studied (Pagani et al. 1994; Stewart 2000). Heart rate variability (HRV) is a marker that can be used as a non-invasive method to reflect autonomic activity (Task Force of the European Society of Cardiology and the North American Society of Pacing and Electrophysiology 1996). The analysis of HRV allows the deduction of the effects of complex variability in biological pathways (Friedman and Thayer 1998). Cardiovascular processes interact with respiration to meet the highly variable metabolic demands of the organism and to maintain homeostasis (Wientjes 1992).