Responses of common diving petrel chicks (Pelecanoides urinatrix) to burrow and colony specific odours in a simple wind tunnel

Researchers have previously assumed that common diving petrels (Pelecanoides urinatrix) have a limited sense of smell since they have relatively small olfactory bulbs. A recent study, however, showed that adult diving petrels prefer the scent of their own burrow compared to burrows of other diving petrels, implying that personal scents contribute to the burrow’s odour signature. Because diving petrels appear to be adapted to use olfaction in social contexts, they could be a useful model for investigating how chemically mediated social recognition develops in birds. A first step is to determine whether diving petrel chicks can detect familiar and unfamiliar odours. We compared behavioural responses of chicks to three natural stimuli in a wind tunnel: soil collected from their burrow or colony, and a blank control. During portions of the experiment, chicks turned the least and walked the shortest distances in response to odours from the nest, which is consistent with their sedentary behaviour within the burrow. By contrast, behaviours linked to olfactory search increased when chicks were exposed to blank controls. These results suggest that common diving petrel chicks can detect natural olfactory stimuli before fledging, and lay the foundation for future studies on the role of olfaction in social contexts for this species

Does maternal exposure to an environmental stressor affect offspring response to predators?

There is growing recognition of the ways in which maternal effects can influence offspring size, physiological performance, and survival. Additionally, environmental contaminants increasingly act as stressors in maternal environments, possibly leading to maternal effects on subsequent offspring. Thus, it is important to determine whether contaminants and other stressors can contribute to maternal effects, particularly under varied ecological conditions that encompass the range under which offspring develop. We used aquatic mesocosms to determine whether maternal effects of mercury (Hg) exposure shape offspring phenotype in the American toad (Bufo americanus) in the presence or absence of larval predators (dragonfly naiads). We found significant maternal effects of Hg exposure and significant effects of predators on several offspring traits, but there was little evidence that maternal effects altered offspring interactions with predators. Offspring from Hg-exposed mothers were 18% smaller than those of reference mothers. Offspring reared with predators were 23% smaller at metamorphosis than those reared without predators. There was also evidence of reduced larval survival when larvae were reared with predators, but this was independent of maternal effects. Additionally, 5 times more larvae had spinal malformations when reared without predators, suggesting selective predation of malformed larvae by predators. Lastly, we found a significant negative correlation between offspring survival and algal density in mesocosms, indicating a role for top-down effects of predators on periphyton communities. Our results demonstrate that maternal exposure to an environmental stressor can induce phenotypic responses in offspring in a direction similar to that produced by direct exposure of offspring to predators

Responses of common diving petrel chicks (Pelecanoides urinatrix) to burrow and colony specific odours in a simple wind tunnel

Researchers have previously assumed that common diving petrels (Pelecanoides urinatrix) have a limited sense of smell since they have relatively small olfactory bulbs. A recent study, however, showed that adult diving petrels prefer the scent of their own burrow compared to burrows of other diving petrels, implying that personal scents contribute to the burrow’s odour signature. Because diving petrels appear to be adapted to use olfaction in social contexts, they could be a useful model for investigating how chemically mediated social recognition develops in birds. A first step is to determine whether diving petrel chicks can detect familiar and unfamiliar odours. We compared behavioural responses of chicks to three natural stimuli in a wind tunnel: soil collected from their burrow or colony, and a blank control. During portions of the experiment, chicks turned the least and walked the shortest distances in response to odours from the nest, which is consistent with their sedentary behaviour within the burrow. By contrast, behaviours linked to olfactory search increased when chicks were exposed to blank controls. These results suggest that common diving petrel chicks can detect natural olfactory stimuli before fledging, and lay the foundation for future studies on the role of olfaction in social contexts for this species

Selective Internal Radiation Therapy (SIRT) with yttrium-90 resin microspheres plus standard systemic chemotherapy regimen of FOLFOX versus FOLFOX alone as first-line treatment of non-resectable liver metastases from colorectal cancer:The SIRFLOX study

BACKGROUND: In colorectal cancer (CRC), unresectable liver metastases are linked to poor prognosis. Systemic chemotherapy with regimens such as FOLFOX (combination of infusional 5-fluorouracil, leucovorin and oxaliplatin) is the standard first-line treatment. The SIRFLOX trial was designed to assess the efficacy and safety of combining FOLFOX-based chemotherapy with Selective Internal Radiation Therapy (SIRT or radioembolisation) using yttrium-90 resin microspheres (SIR-Spheres®; Sirtex Medical Limited, North Sydney, Australia). METHODS/DESIGN: SIRFLOX is a randomised, multicentre trial of mFOLFOX6 chemotherapy ± SIRT as first-line treatment of patients with liver-only or liver-predominant metastatic CRC (mCRC). The trial aims to recruit adult chemotherapy-naïve patients with proven liver metastases with or without limited extra-hepatic disease, a life expectancy of ≥3 months and a WHO performance status of 0–1. Patients will be randomised to receive either mFOLFOX6 or SIRT + mFOLFOX6 (with a reduced dose of oxaliplatin in cycles 1–3 following SIRT). Patients in both arms can receive bevacizumab at investigator discretion. Protocol chemotherapy will continue until there is unacceptable toxicity, evidence of tumour progression, complete surgical resection or ablation of cancerous lesions, or the patient requests an end to treatment. The primary endpoint of the SIRFLOX trial is progression-free survival (PFS). Secondary endpoints include: PFS in the liver; tumour response rate (liver and any site); site of tumour progression; health-related quality of life; toxicity and safety; liver resection rate; and overall survival. Assuming an increase in the median PFS from 9.4 months to 12.5 months with the addition of SIRT to mFOLFOX6, recruiting ≥450 patients will be sufficient for 80% power and 95% confidence. DISCUSSION: The SIRFLOX trial will establish the potential role of SIRT + standard systemic chemotherapy in the first-line management of mCRC with non-resectable liver metastases. TRIAL REGISTRATION: SIRFLOX ClinicalTrials.gov identifier: NCT00724503. Registered 25 July 2008. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/1471-2407-14-897) contains supplementary material, which is available to authorized users