RESUMO
Understanding the processes that drive interpopulation differences in demography and population dynamics is central to metapopulation ecology. In colonial species, populations are limited by local resource availability. However, individuals from larger colonies will travel greater distances to overcome density-dependent competition. Consequently, these individuals may also experience greater carry-over effects and interpopulation differences in demography. To test this prediction, we use mark-recapture data collected over four decades from two breeding colonies of a seabird, the Manx shearwater (Puffinus puffinus), that exhibit strong spatial overlap throughout the annual cycle but differ in population size and maximum foraging distances. We quantify interpopulation differences and synchrony in rates of survival and assess whether local mean wind speeds act to strengthen or disrupt synchrony. In addition, we examine whether the imputed interpopulation differences in survival can generate population-level consequences. The colony where individuals travel further during the breeding season had slightly lower and more variable rates of survival, indicative of individuals experiencing greater carry-over effects. Fluctuations in survival were highly synchronous between the colonies, but neither synchronous, nor asynchronous, variation could be strongly attributed to fluctuations in local mean wind speeds. Finally, we demonstrate that the imputed interpopulation differences in rates of survival could lead to considerable differences in population growth. We hypothesise that the observed interpopulation differences in rates of adult survival reflect carry-over effects associated with foraging distances during the breeding season. More broadly, our results highlight that breeding season processes can be important for understanding interpopulation differences in the demographic rates and population dynamics of long-lived species, such as seabirds.
RESUMO
Locoregional esophageal cancer is currently treated with induction chemoradiotherapy, followed by esophagectomy with reconstruction, using a gastric conduit. In cases of conduit failure, patients are temporized with a cervical esophagostomy and enteral nutrition until gastrointestinal continuity can be established. At our institution, we favor reconstruction, using a colon interposition with a 'supercharged' accessory vascular pedicle. Consequently, we sought to examine our technique and outcomes for esophageal reconstruction, using this approach. We performed a retrospective review of all patients who underwent esophagectomy at our center between 2008 and 2018. We identified those patients who had a failed gastric conduit and underwent secondary reconstruction. Patient demographics, perioperative details, and clinical outcomes were analyzed after our clinical care pathway was used to manage and prepare patients for a second major reconstructive surgery. Three hundred and eighty eight patients underwent esophagectomy and reconstruction with a gastric conduit. Seven patients (1.8%) suffered gastric conduit loss and underwent a secondary reconstruction using a colon interposition with a 'supercharged' vascular pedicle. Mean age was 70.1 (±7.3) years, and six patients were male. The transverse colon was used in four cases (57.1%), left colon in two cases (28.6%), and right colon in one case (14.3%). There were no deaths or loss of the colon interposition at follow-up. Three patients (42.9%) developed an anastomotic leak, which resolved with conservative management. All patients had resumption of oral intake within 30 days. Utilizing a 'supercharging' technique for colon interposition may improve the perfusion to the organ and may decrease morbidity. Secondary reconstruction should occur when the patient's oncologic, physiologic, and psychosocial condition is optimized. Our outcomes and preoperative strategies may provide guidance for those centers treating this complicated patient population.