ABSTRACT
The Challenge Hypothesis is an influential framework for understanding how androgens are involved in the promotion of competitive behavior during mating-related challenges and has been tested extensively in studies across scientific disciplines. Mixed support in psychological research led scholars to develop the Dual Hormone Hypothesis as a potential path forward, which argues that glucocorticoids moderate the relationship between androgens and status-striving. In the current study, we examine the Challenge Hypothesis and the Dual Hormone Hypothesis in wild male mountain gorillas, representing the first time the latter hypothesis has been tested in a non-human primate. In a sample of 30 adult males comprising over 600 days of observation, we find some limited support for the Challenge Hypothesis. Greater daily rates of targeted aggression toward other adult males corresponded to higher fecal androgen metabolites 1-2 days following observations, though this pattern did not fully generalize to dominance rank or other competitive behaviors examined. However, we find no support for the Dual Hormone Hypothesis: neither dominance rank nor any category of competitive behavior was predicted by the interaction between androgens and glucocorticoids. We close by discussing how this initial investigation might be leveraged toward the development of an expanded Dual Hormone Hypothesis that draws on the large evidence base in primate behavioral ecology.
ABSTRACT
PURPOSE: The significance of the validated biomarkers of sepsis Mid-regional pro-atrial natriuretic peptide (MR-proANP) and copeptin have not been tested in a burn injury setting. MATERIALS AND METHODS: 42 consecutive patients were included in a prospective observational study. Daily blood specimens collected over the initial 20â¯days of treatment were quantitatively analysed by immunoluminometric sandwich assay (Kryptor, BRAHMS, Berlin, Germany) for MR-proANP, copeptin and procalcitonin (PCT). RESULTS: In patients with absence of sepsis, copeptin levels initially increased post-burn injury and thereafter rapidly declined. In contrast, MR-proANP was only slightly elevated within the first few days. MR-proANP [199.8 (115.6; 399.5) vs 160.1 (93.7; 280.6), Pâ¯<â¯.007] and PCT [1.12 (0.32; 2.22) vs 0.32 (0.16; 0.53), Pâ¯<â¯.001] levels were significantly higher on days of sepsis. Copeptin, however, showed no significant differences [20.7 (11.8; 42.2) vs 16.8 (11.0; 30.6), Pâ¯=â¯.11]. Both, MR-proANP and PCT level increases were noted upon the first day of sepsis. CONCLUSION: Burn injury itself maybe associated with copeptin and to a lesser degree MR-proANP level increases. Subsequent increases in MR-proANP may be considered diagnostic for sepsis but demonstrated no advantages over PCT. The role of copeptin remains inappropriate for diagnosing sepsis after burn injury (ClinicalTrials.gov number, NCT01055587).
