Now showing 1 - 3 of 3
  • Publication
    The role of awakening cortisol and psychological distress in diurnal variations in affect : a day reconstruction study
    (University College Dublin. Geary Institute, 2010-07) ; ; ;
    People often feel unhappy in the morning but better later in the day, and this pattern may be amplified in the distressed. Past work suggests that one function of cortisol is to energize people in the mornings. In a study of 174 students we tested to see if daily affect patterns, psychological distress, and awakening cortisol levels were interlinked. Affect levels were assessed using the Day Reconstruction Method (Kahneman, Krueger, Schkade, Schwarz, & Stone, 2004) and psychological distress was measured using the Depression Anxiety Stress Scales (Antony, Bieling, Cox, Enns, & Swinson, 1998). On average positive affect increased markedly in a linear pattern across the day whilst negative affect decreased linearly. For the highly distressed this pattern was stronger for positive affect. Lower than average morning cortisol, as assessed by two saliva samples at waking and two samples 30 minutes after waking, predicted a clear increasing pattern of positive affect throughout the day. When we examined the interlinkages between affect patterns, distress, and cortisol our results showed that a pronounced linear increase in positive affect from morning through to evening occurred chiefly among distressed people with below average cortisol levels upon awakening. Psychological distress, whilst not strongly associated with morning cortisol levels, does appear to interact with cortisol levels to profoundly influence affect.
  • Publication
    Naturalistic monitoring of the affect-heart rate relationship : a day reconstruction study
    (University College Dublin. Geary Institute, 2009-01-02) ; ; ; ;
    Objective: Prospective studies have linked both negative affective states and trait neuroticism with hypertension, cardiovascular disease, and mortality. However, identifying how fluctuations in cardiovascular activity in day-to-day settings are related to changes in affect and stable personality characteristics has remained a methodological and logistical challenge. Design: In the present study, we tested the association between affect, affect variability, personality and heart rate (HR) in daily life. Measures: We utilized an online day reconstruction survey to produce a continuous account of affect, interaction, and activity patterns during waking hours. Ambulatory HR was assessed during the same period. Consumption, activity, and baseline physiological characteristics were assessed in order to isolate the relationships between affect, personality and heart rate. Results: Negative affect and variability in positive affect predicted an elevated ambulatory HR and tiredness a lower HR. Emotional stability was inversely related to HR, whereas agreeableness predicted a higher HR. Baseline resting HR was unrelated to either affect or personality. Conclusion: The results suggest that both state and trait factors implicated in negative affectivity may be risk factors for increased cardiovascular reactivity in everyday life. Combining day reconstruction with psychophysiological and environmental monitoring is discussed as a minimally invasive method with promising interdisciplinary relevance.
  • Publication
    In Silico Promoter Analysis can Predict Genes of Functional Relevance in Cell Proliferation: Validation in a Colon Cancer Model
    (Libertas Academica, 2007-01) ; ;
    Specific combinations of transcription-factor binding sites in the promoter regions of genes regulate gene expression, and thus key functional processes in cells. Analysis of such promoter regions in specific functional contexts can be used to delineate novel disease-associated genes based on shared phenotypic properties. The aim of this study was to utilize promoter analysis to predict cell proliferation-associated genes and to test this method in colon cancer cell lines. We used freely-available bioinformatic techniques to identify cell-proliferation-associated genes expressed in colon cancer, extract a shared promoter module, and identify novel genes that also contain this module in the human genome. An EGRF/ETSF promoter module was identified as prevalent in proliferation-associated genes from a colon cancer cDNA library. We detected 30 other genes, from the known promoters of the human genome, which contained this proliferation-associated module. This group included known proliferation-associated genes, such as HERG1 and MCM7, and a number of genes not previously implicated in cell proliferation in cancer, such as TSPAN3, Necdin and APLP2. Suppression of TSPAN3 and APLP2 by siRNA was performed and confirmed by RT-PCR. Inhibition of these genes significantly inhibited cell proliferation in colon cancer cell lines. This study demonstrates that promoter analysis can be used to identify novel cancer-associated genes based on shared functional processes.