Long‐term trends in the survival rates of adult female Common Eider Somateria mollissima at three colonies in Iceland

Ibis ◽  
2020 ◽  
Author(s):  
Kevin A. Wood ◽  
Sverrir Thorstensen ◽  
Smári J. Lúðvíksson ◽  
Kane Brides ◽  
Aevar Petersen
Author(s):  
Sage Ellis ◽  
Madeleine Lohman ◽  
James Sedinger ◽  
Perry Williams ◽  
Thomas Riecke

Sex ratios affect population dynamics and individual fitness, and changing sex ratios can be indicative of shifts in sex-specific survival at different life stages. While climate- and landscape-change alter sex ratios of wild bird populations, long-term, landscape scale assessments of sex ratios are rare. Further, little work has been done to understand changes in sex ratios in avian communities. In this manuscript, we analyse long-term (1961-2015) data on five species of ducks across five broad climatic regions of the United States to estimate the effects of drought and long-term trends on the proportion of juvenile females captured at banding. As waterfowl have a 1:1 sex ratio at hatch, we interpret changes in sex ratios of captured juveniles as changes in sex-specific survival rates during early life. Seven of twelve species-region pairs exhibited evidence for long-term trends in the proportion of juvenile females at banding. The proportion of juvenile females at banding increased for duck populations in the western United States and typically declined for duck populations in the eastern United States. We only observed evidence for an effect of drought in two of the twelve species-region pairs, where the proportion of females declined during drought. As changes to North American landscapes and climate continue and intensify, we expect continued changes in sex-specific juvenile survival rates. More broadly, we encourage further research examining the mechanisms underlying long-term trends in juvenile sex ratios in avian communities.


2012 ◽  
Vol 30 (15_suppl) ◽  
pp. e14512-e14512
Author(s):  
Zhensheng Wang ◽  
Michael Goodman ◽  
Hemchandra Mahaseth ◽  
Bassel F El-Rayes

e14512 Background: The incidence of esophageal squamous cell (ESC) carcinoma has been decreasing, while incidence of esophageal adenocarcinoma (EA) keeps increasing. The specific time periods during which incidence trends changed have not been examined. Secular trends in survival and changes of those trends need to be investigated. Methods: Incidence and survival were analyzed using joinpoint regression models, which are designed to examine long-term longitudinal data for a change in trend. We identified 75,497 patients with esophageal cancer and adenocarcinoma of the gastric cardia (GCA) in the Surveillance, Epidemiology, and End Results database between 1973 and 2008. Incidence and one-year survival rates for ESC, EA, and GCA were compared by race, gender and stage. Results were expressed in terms of identifiable inflexion points (joinpoints) with before-and-after estimates of annual percent changes (APC) with 95% confidence intervals (CI). Results: Incidence of ESC has demonstrated a clear inflexion point in the mid 1980s with accelerated decrease across race and gender categories. While incidence of EA has been increasing, the increase slowed down in mid 90s in all groups except blacks. For GCA, there was a clear increase in incidence up until early 80s followed by a plateau although in men there was a significant post-87 decrease. One-year survival of ESC patients has been improving; for local/regional disease the trend became less pronounced in late 80s whereas for distant disease the improvement appears to continue without identifiable inflexion points. The patterns of one-year survival for EA and GCA were similar. Local/regional diseases demonstrated a significant improvement in survival without changes in trend while survival of distant diseases showed an inflexion point in the mid 90s followed by a marked improvement. Conclusions: Joinpoint regression analysis is a valuable tool in assessing long-term trends of incidence and survival. The survival of ESC, EA, and GCA demonstrated significant improvement over the last 35 years. The inflexion points reflected introduction of combined modality therapy for regional disease and availability of newer chemotherapy agents for distant disease.


2019 ◽  
Vol 286 (1910) ◽  
pp. 20191356 ◽  
Author(s):  
A. Morrill ◽  
J. F. Provencher ◽  
H. G. Gilchrist ◽  
M. L. Mallory ◽  
M. R. Forbes

Field experiments where parasites are removed through treatment and contaminant levels in host tissues are recorded can provide insight into the combined effects of parasitism and contaminants in wild populations. In 2013 and 2014, we treated northern common eider ducks ( Somateria mollissima ) arriving at a breeding colony with either a broad-spectrum antihelminthic (PANACUR ® ) or distilled water, and measured their blood lead (Pb) levels. Breeding propensity and clutch sizes were inversely related to Pb in both treatment groups. In comparison, a negative effect of Pb on resight probability the following year was observed only in the anti-parasitic treatment (APT) group. These contrasting patterns suggest a long-term benefit to survival of intestinal parasitism in eiders experiencing Pb exposure. The arrival date of hens explained some, but not all, of the effects of Pb. We weigh the merits of different hypotheses in explaining our results, including protective bioaccumulation of Pb by parasites, condition-linked thresholds to costly reproduction and the direct effects of APT on eider health. We conclude that variation in helminth parasitism influences survival in this migratory bird in counterintuitive ways.


2014 ◽  
Vol 513 ◽  
pp. 143-153 ◽  
Author(s):  
CD Stallings ◽  
JP Brower ◽  
JM Heinlein Loch ◽  
A Mickle

2012 ◽  
Vol 15 (1) ◽  
pp. 4 ◽  
Author(s):  
David M. Holzhey ◽  
William Shi ◽  
A. Rastan ◽  
Michael A. Borger ◽  
Martin H�nsig ◽  
...  

<p><b>Introduction:</b> The goal of this study was to compare the short- and long-term outcomes after aortic valve (AV) surgery carried out via standard sternotomy/partial sternotomy versus transapical transcatheter AV implantation (taTAVI).</p><p><b>Patients and Methods:</b> All 336 patients who underwent taTAVI between 2006 and 2010 were compared with 4533 patients who underwent conventional AV replacement (AVR) operations between 2001 and 2010. Using propensity score matching, we identified and consecutively compared 2 very similar groups of 167 patients each. The focus was on periprocedural complications and long-term survival.</p><p><b>Results:</b> The 30-day mortality rate was 10.8% and 8.4% (<i>P</i> = .56) for the conventional AVR patients and the TAVI patients, respectively. The percentages of postoperative pacemaker implantations (15.0% versus 6.0%, <i>P</i> = .017) and cases of renal failure requiring dialysis (25.7% versus 12.6%, <i>P</i> = .004) were higher in the TAVI group. Kaplan-Meier curves diverged after half a year in favor of conventional surgery. The estimated 3-year survival rates were 53.5% � 5.7% (TAVI) and 66.7% � 0.2% (conventional AVR).</p><p><b>Conclusion:</b> Our study shows that even with all the latest successes in catheter-based AV implantation, the conventional surgical approach is still a very good treatment option with excellent long-term results, even for older, high-risk patients.</p>


2011 ◽  
Vol 14 (4) ◽  
pp. 237 ◽  
Author(s):  
Ferdinand Vogt ◽  
Anke Kowert ◽  
Andres Beiras-Fernandez ◽  
Martin Oberhoffer ◽  
Ingo Kaczmarek ◽  
...  

<p><b>Objective:</b> The use of homografts for aortic valve replacement (AVR) is an alternative to mechanical or biological valve prostheses, especially in younger patients. This retrospective comparative study evaluated our single-center long-term results, with a focus on the different origins of the homografts.</p><p><b>Methods:</b> Since 1992, 366 adult patients have undergone AVR with homografts at our center. We compared 320 homografts of aortic origin and 46 homografts of pulmonary origin. The grafts were implanted via either a subcoronary technique or the root replacement technique. We performed a multivariate analysis to identify independent factors that influence survival. Freedom from reintervention and survival rates were calculated as cumulative events according to the Kaplan-Meier method, and differences were tested with the log-rank test.</p><p><b>Results:</b> Overall mortality within 1 year was 6.5% (21/320) in the aortic graft group and 17.4% (8/46) in the pulmonary graft group. In the pulmonary graft group, 4 patients died from valve-related complications, 1 patient died after additional heterotopic heart transplantation, and 1 patient who entered with a primary higher risk died from a prosthesis infection. Two patients died from non-valve-related causes. During the long-term follow-up, the 15-year survival rate was 79.9% for patients in the aortic graft group and 68.7% for patients in the pulmonary graft group (<i>P</i> = .049). The rate of freedom from reoperation was 77.7% in the aortic graft group and 57.4% in the pulmonary graft group (<i>P</i> < .001). The reasons for homograft explantation were graft infections (aortic graft group, 5.0%; pulmonary graft group, 6.5%) and degeneration (aortic graft group, 7.5%; pulmonary graft group, 32.6%).</p><p><b>Conclusion:</b> Our study demonstrated superior rates of survival and freedom from reintervention after AVR with aortic homografts. Implantation with a pulmonary graft was associated with a higher risk of redo surgery, owing to earlier degenerative alterations.</p>


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