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Many animals use assessment signals to resolve contests over limited resources while minimizing the costs of those contests. The carotenoid‐based orange to red bills of male zebra finches (Taeniopygia guttata) are thought to function as assessment signals in male–male contests, but behavioral analyses relating contest behaviors and outcomes to bill coloration have yielded mixed results. We examined the relationship between bill color and contests while incorporating measurements of color perception and testosterone (T) production, for an integrative view of aggressive signal behavior, production, and perception. We assayed the T production capabilities of 12 males in response to a gonadotropin‐releasing hormone (GnRH) challenge. We then quantified the initiation, escalation, and outcome of over 400 contests in the group, and measured bill color using calibrated photography. Finally, because signal perception can influence signal function, we tested how males perceive variation in bill coloration, asking if males exhibit categorical perception of bill color, as has been shown recently in female zebra finches. The data suggest that males with greater T production capabilities than their rivals were more likely to initiate contests against those rivals, while males with redder bills than their rivals were more likely to win contests. Males exhibited categorical color perception, but individual variation in the effect of categorical perception on color discrimination abilities did not predict any aspects of contest behavior or outcomes. Our results are consistent with the hypotheses that T plays a role in zebra finch contests and that bill coloration functions as an aggressive signal. We suggest future approaches, based on animal contest theory, for how links among signals, perception, and assessment can be tested. [ABSTRACT FROM AUTHOR]

Despite being one of the leading causes of maternal death and a major contributor of maternal and perinatal morbidity, the mechanisms responsible for the pathogenesis of pre-eclampsia have yet to be fully elucidated. However, it is evident that this is a complex disorder involving multiple organ systems, and by using integrative approaches, enormous progress has been made towards understanding the pathophysiology of pre-eclampsia. Growing evidence supports the concept that the placenta plays a central role in the pathogenesis of pre-eclampsia and that reduced uteroplacental perfusion, which develops as a result of abnormal cytotrophoblast invasion of spiral arterioles, triggers the cascade of events leading to the maternal disorder. Placental ischaemia leads to release of soluble placental factors, many of which are classified as anti-angiogenic or pro-inflammatory. Once these ischaemic placental factors reach the maternal circulation, they cause widespread activation and dysfunction of the maternal vascular endothelium that results in enhanced formation of endothelin-1 and superoxide, increased vascular sensitivity to angiotensin II and decreased formation of vasodilators such as nitric oxide. This review highlights these links between placental ischaemia, maternal endothelial activation and renal dysfunction in the pathogenesis of hypertension in pre-eclampsia. [ABSTRACT FROM AUTHOR]

Objective: Frailty is the loss of physical or mental reserve that impairs function, often in the absence of a defined comorbidity. Our aim was to determine whether a modified frailty index (mFI) correlates with morbidity and mortality in patients undergoing hysterectomy., Design: Retrospective cohort study., Setting: Hospitals across the USA participating in the National Surgical Quality Improvement Program (NSQIP)., Sample: Patients who underwent hysterectomy from 2008 to 2012., Methods: An mFI was calculated using 11 variables in NSQIP. The associations between mFI and morbidity and mortality were assessed. Model fit statistics (c-statistics) were utilised to evaluate the ability of mFI to distinguish outcomes., Main Outcome Measure: Wound infection, severe complications and mortality., Results: A total of 66 105 patients were identified. Wound complications increased from 2.4% in patients with an mFI of zero to 4.8% in those with mFI ≥ 0.5 (P < 0.0001). Similarly, severe complications increased from 0.98% to 7.3% (P < 0.0001), overall complications rose from 3.7% to 14.5% (P < 0.0001) and mortality increased from 0.06% to 3.2% (P < 0.0001) for patients with a frailty index of zero compared with those with an index of ≥ 0.5. Versus chance, the goodness-of-fit c-statistics suggested that mFI increases the ability to detect wound complications by 11.4%, severe complications by 22.0% and overall complications by 11.0%., Conclusions: The mFI is easily reproducible from routinely collected clinical data and predictive of outcomes in patients undergoing hysterectomy. Frailty may be useful in the preoperative risk assessment of women undergoing gynaecological surgery., Tweetable Abstract: Frailty may be useful in the preoperative risk assessment of women undergoing gynaecological surgery., (© 2015 Royal College of Obstetricians and Gynaecologists.)