45 research outputs found
Coping with climate change:Energetic costs of avian timing of reproduction
Het broedsucces van veel bosvogels, waaronder koolmezen, hangt af van de timing van het broeden ten opzichte van de timing van de jaarlijkse rupsenpiek. Door klimaatsverandering vindt de rupsenpiek nu gemiddeld drie weken eerder plaats dan 30 jaar geleden. Koolmezen zijn ook vroeger gaan broeden, maar niet vroeg genoeg om de verschuiving van het voedsel van hun jongen bij te benen. Een mogelijke verklaring is dat er niet voldoende voedsel aanwezig om vroeg genoeg te kunnen broeden. Door tegelijk de insectenbeschikbaarheid en het foerageergedrag van koolmeesvrouwtjes te meten, zagen we dat de koolmezen vooral foerageerden in bomen waar op dat moment de meeste insecten te vinden waren, ondanks het feit dat er volop zaden aanwezig waren die relatief veel meer energie bevatten dan insecten. Opvallend was dat veel koolmezen begonnen met leggen op het moment dat insectenaantallen in snel tempo toenamen na een periode van lage insectenbeschikbaarheid, wat duidt op een mogelijke eiwitbeperking voor eiproductie. Vroeger eileggen kan waarschijnlijk niet zonder een verhoging van de energetische uitgaven omdat eieren dan geproduceerd moeten worden onder koudere omstandigheden, bij lage voedselbeschikbaarheid en lage efficientie van voedselzoeken. Als de fitnessvoordelen van vroeg broeden niet opwegen tegen de fitnesskosten van de verhoogde energetische uitgaven, is het beter later te broeden om de totale fitness te maximaliseren. Helaas hebben we niet kunnen aantonen dat koolmezen door ‘te laat’ te broeden en daardoor de voedselpiek deels missen hun fitness maximaliseerde, doordat we er niet in slaagden om koolmezen vroeger te laten broeden
Coping with climate change : energetic costs of avian timing of reproduction
Het broedsucces van veel bosvogels, waaronder koolmezen, hangt af van de timing van het broeden ten opzichte van de timing van de jaarlijkse rupsenpiek. Door klimaatsverandering vindt de rupsenpiek nu gemiddeld drie weken eerder plaats dan 30 jaar geleden. Koolmezen zijn ook vroeger gaan broeden, maar niet vroeg genoeg om de verschuiving van het voedsel van hun jongen bij te benen. Een mogelijke verklaring is dat er niet voldoende voedsel aanwezig om vroeg genoeg te kunnen broeden. Door tegelijk de insectenbeschikbaarheid en het foerageergedrag van koolmeesvrouwtjes te meten, zagen we dat de koolmezen vooral foerageerden in bomen waar op dat moment de meeste insecten te vinden waren, ondanks het feit dat er volop zaden aanwezig waren die relatief veel meer energie bevatten dan insecten. Opvallend was dat veel koolmezen begonnen met leggen op het moment dat insectenaantallen in snel tempo toenamen na een periode van lage insectenbeschikbaarheid, wat duidt op een mogelijke eiwitbeperking voor eiproductie.
Vroeger eileggen kan waarschijnlijk niet zonder een verhoging van de energetische uitgaven omdat eieren dan geproduceerd moeten worden onder koudere omstandigheden, bij lage voedselbeschikbaarheid en lage efficientie van voedselzoeken. Als de fitnessvoordelen van vroeg broeden niet opwegen tegen de fitnesskosten van de verhoogde energetische uitgaven, is het beter later te broeden om de totale fitness te maximaliseren. Helaas hebben we niet kunnen aantonen dat koolmezen door ‘te laat’ te broeden en daardoor de voedselpiek deels missen hun fitness maximaliseerde, doordat we er niet in slaagden om koolmezen vroeger te laten broeden.
The breeding success of most forest birds, like great tits, strongly depends on the timing of breeding relative to the timing of the caterpillar food peak. Climate change caused the annual food peak to advance. Great tits advanced breeding, but not sufficiently to match the shift of the food peak. One possible explanation for the lack of shift is that there is not enough food to start laying early enough to be synchronized with the caterpillar food peak. We monitored insect availability and great tit foraging behaviour simultaneously and show that females foraged in those trees which at that moment had highest insect availability, even though seeds, which contain much more energy, were abundant. Laying dates of the earliest laying great tits coincided with a steep increase in insect availability after a period of low insect abundance, suggesting a possible protein restriction on egg production.
Advancing laying to increase the synchrony between nestling food demand and caterpillar availability will come with an increased energetic costs during egg laying, as eggs will be produced under colder conditions while food availability and foraging efficiency are low. The fitness cost of the increasing energetic costs needed to advance egg laying may not outweigh the fitness benefits gained by breeding earlier and thus mismatched reproduction can be adaptive. Unfortunately we were not able to test if the current (mismatched) timing of reproduction is adaptive as we were not able to experimentally advance egg laying in free living great tits, which is needed to confirm this hypothesis.
Manipulation of Life-History Decisions Using Leptin in a Wild Passerine
Seasonal timing of reproduction and the number of clutches produced per season are two key avian life-history traits with major fitness consequences. Female condition may play an important role in these decisions. In mammals, body condition and leptin levels are correlated. In birds, the role of leptin remains unclear. We did two experiments where we implanted female great tits with a pellet releasing leptin evenly for 14 days, to manipulate their perceived body condition, or a placebo pellet. In the first experiment where females were implanted when feeding their first brood offspring we found, surprisingly, that placebo treated females were more likely to initiate a second brood compared to leptin treated females. Only one second brood fledged two chicks while five were deserted late in the incubation stage or when the first egg hatched. No difference was found in female or male return rate or in recruitment rate of fledglings of the first brood, possibly due to the desertion of the second broods. In our study population, where there is selection for early egg laying, earlier timing of reproduction might be hampered by food availability and thus nutritional state of the female before egg laying. We therefore implanted similar leptin pellets three weeks before the expected start of egg laying in an attempt to manipulate the laying dates of first clutches. However, leptin treated females did not initiate egg laying earlier compared to placebo treated females, suggesting that other variables than the perceived body condition play a major role in the timing of reproduction. Also, leptin treatment did not affect body mass, basal metabolic rate or feeding rates in captive females. Manipulating life history decisions using experimental protocols which do not alter individuals' energy balance are crucial in understanding the trade-off between costs and benefits of life history decisions
Investigation of the international comparability of population-based routine hospital data set derived comorbidity scores for patients with lung cancer
Introduction: The International Cancer Benchmarking Partnership (ICBP) identified significant international differences in lung cancer survival. Differing levels of comorbid disease across ICBP countries has been suggested as a potential explanation of this variation but, to date, no studies have quantified its impact. This study investigated whether comparable, robust comorbidity scores can be derived from the different routine population-based cancer data sets available in the ICBP jurisdictions and, if so, use them to quantify international variation in comorbidity and determine its influence on outcome.
Methods: Linked population-based lung cancer registry and hospital discharge data sets were acquired from nine ICBP jurisdictions in Australia, Canada, Norway and the UK providing a study population of 233 981 individuals. For each person in this cohort Charlson, Elixhauser and inpatient bed day Comorbidity Scores were derived relating to the 4–36 months prior to their lung cancer diagnosis. The scores were then compared to assess their validity and feasibility of use in international survival comparisons.
Results: It was feasible to generate the three comorbidity scores for each jurisdiction, which were found to have good content, face and concurrent validity. Predictive validity was limited and there was evidence that the reliability was questionable.
Conclusion: The results presented here indicate that interjurisdictional comparability of recorded comorbidity was limited due to probable differences in coding and hospital admission practices in each area. Before the contribution of comorbidity on international differences in cancer survival can be investigated an internationally harmonised comorbidity index is required
Energy expenditure during egg laying is equal for early and late breeding free-living female great tits
In many bird populations, variation in the timing of reproduction exists but it is not obvious how this variation is maintained as timing has substantial fitness consequences. Daily energy expenditure (DEE) during the egg laying period increases with decreasing temperatures and thus perhaps only females that can produce eggs at low energetic cost will lay early in the season, at low temperatures. We tested whether late laying females have a higher daily energy expenditure during egg laying than early laying females in 43 great tits (Parus major), by comparing on the same day the DEE of early females late in their laying sequence with DEE of late females early in their egg laying sequence. We also validated the assumption that there are no within female differences in DEE within the egg laying sequence. We found a negative effect of temperature and a positive effect of female body mass on DEE but no evidence for differences in DEE between early and late laying females. However, costs incurred during egg laying may have carry-over effects later in the breeding cycle and if such carry-over effects differ for early and late laying females this could contribute to the maintenance of phenotypic variation in laying dates
Risk factors and prognostic implications of diagnosis of cancer within 30 days after an emergency hospital admission (emergency presentation): an International Cancer Benchmarking Partnership (ICBP) population-based study
BACKGROUND: Greater understanding of international cancer survival differences is needed. We aimed to identify predictors and consequences of cancer diagnosis through emergency presentation in different international jurisdictions in six high-income countries. METHODS: Using a federated analysis model, in this cross-sectional population-based study, we analysed cancer registration and linked hospital admissions data from 14 jurisdictions in six countries (Australia, Canada, Denmark, New Zealand, Norway, and the UK), including patients with primary diagnosis of invasive oesophageal, stomach, colon, rectal, liver, pancreatic, lung, or ovarian cancer during study periods from Jan 1, 2012, to Dec 31, 2017. Data were collected on cancer site, age group, sex, year of diagnosis, and stage at diagnosis. Emergency presentation was defined as diagnosis of cancer within 30 days after an emergency hospital admission. Using logistic regression, we examined variables associated with emergency presentation and associations between emergency presentation and short-term mortality. We meta-analysed estimates across jurisdictions and explored jurisdiction-level associations between cancer survival and the percentage of patients diagnosed as emergencies. FINDINGS: In 857 068 patients across 14 jurisdictions, considering all of the eight cancer sites together, the percentage of diagnoses through emergency presentation ranged from 24·0% (9165 of 38 212 patients) to 42·5% (12 238 of 28 794 patients). There was consistently large variation in the percentage of emergency presentations by cancer site across jurisdictions. Pancreatic cancer diagnoses had the highest percentage of emergency presentations on average overall (46·1% [30 972 of 67 173 patients]), with the jurisdictional range being 34·1% (1083 of 3172 patients) to 60·4% (1317 of 2182 patients). Rectal cancer had the lowest percentage of emergency presentations on average overall (12·1% [10 051 of 83 325 patients]), with a jurisdictional range of 9·1% (403 of 4438 patients) to 19·8% (643 of 3247 patients). Across the jurisdictions, older age (ie, 75-84 years and 85 years or older, compared with younger patients) and advanced stage at diagnosis compared with non-advanced stage were consistently associated with increased emergency presentation risk, with the percentage of emergency presentations being highest in the oldest age group (85 years or older) for 110 (98%) of 112 jurisdiction-cancer site strata, and in the most advanced (distant spread) stage category for 98 (97%) of 101 jurisdiction-cancer site strata with available information. Across the jurisdictions, and despite heterogeneity in association size (I2=93%), emergency presenters consistently had substantially greater risk of 12-month mortality than non-emergency presenters (odds ratio >1·9 for 112 [100%] of 112 jurisdiction-cancer site strata, with the minimum lower bound of the related 95% CIs being 1·26). There were negative associations between jurisdiction-level percentage of emergency presentations and jurisdiction-level 1-year survival for colon, stomach, lung, liver, pancreatic, and ovarian cancer, with a 10% increase in percentage of emergency presentations in a jurisdiction being associated with a decrease in 1-year net survival of between 2·5% (95% CI 0·28-4·7) and 7·0% (1·2-13·0). INTERPRETATION: Internationally, notable proportions of patients with cancer are diagnosed through emergency presentation. Specific types of cancer, older age, and advanced stage at diagnosis are consistently associated with an increased risk of emergency presentation, which strongly predicts worse prognosis and probably contributes to international differences in cancer survival. Monitoring emergency presentations, and identifying and acting on contributing behavioural and health-care factors, is a global priority for cancer control. FUNDING: Canadian Partnership Against Cancer; Cancer Council Victoria; Cancer Institute New South Wales; Cancer Research UK; Danish Cancer Society; National Cancer Registry Ireland; The Cancer Society of New Zealand; National Health Service England; Norwegian Cancer Society; Public Health Agency Northern Ireland, on behalf of the Northern Ireland Cancer Registry; the Scottish Government; Western Australia Department of Health; and Wales Cancer Network
Worldwide trends in population-based survival for children, adolescents, and young adults diagnosed with leukaemia, by subtype, during 2000–14 (CONCORD-3) : analysis of individual data from 258 cancer registries in 61 countries
Background Leukaemias comprise a heterogenous group of haematological malignancies. In CONCORD-3, we analysed
data for children (aged 0–14 years) and adults (aged 15–99 years) diagnosed with a haematological malignancy
during 2000–14 in 61 countries. Here, we aimed to examine worldwide trends in survival from leukaemia, by age and
morphology, in young patients (aged 0–24 years).
Methods We analysed data from 258 population-based cancer registries in 61 countries participating in CONCORD-3
that submitted data on patients diagnosed with leukaemia. We grouped patients by age as children (0–14 years),
adolescents (15–19 years), and young adults (20–24 years). We categorised leukaemia subtypes according to the
International Classification of Childhood Cancer (ICCC-3), updated with International Classification of Diseases
for Oncology, third edition (ICD-O-3) codes. We estimated 5-year net survival by age and morphology, with 95% CIs,
using the non-parametric Pohar-Perme estimator. To control for background mortality, we used life tables by
country or region, single year of age, single calendar year and sex, and, where possible, by race or ethnicity. All-age
survival estimates were standardised to the marginal distribution of young people with leukaemia included in the
analysis.
Findings 164563 young people were included in this analysis: 121328 (73·7%) children, 22963 (14·0%) adolescents, and
20272 (12·3%) young adults. In 2010–14, the most common subtypes were lymphoid leukaemia (28205 [68·2%] patients)
and acute myeloid leukaemia (7863 [19·0%] patients). Age-standardised 5-year net survival in children, adolescents, and
young adults for all leukaemias combined during 2010–14 varied widely, ranging from 46% in Mexico to more than
85% in Canada, Cyprus, Belgium, Denmark, Finland, and Australia. Individuals with lymphoid leukaemia had better
age-standardised survival (from 43% in Ecuador to ≥80% in parts of Europe, North America, Oceania, and Asia) than
those with acute myeloid leukaemia (from 32% in Peru to ≥70% in most high-income countries in Europe,
North America, and Oceania). Throughout 2000–14, survival from all leukaemias combined remained consistently
higher for children than adolescents and young adults, and minimal improvement was seen for adolescents and young
adults in most countries.
Interpretation This study offers the first worldwide picture of population-based survival from leukaemia in children,
adolescents, and young adults. Adolescents and young adults diagnosed with leukaemia continue to have lower
survival than children. Trends in survival from leukaemia for adolescents and young adults are important indicators
of the quality of cancer management in this age group.peer-reviewe
Global survival trends for brain tumors, by histology: analysis of individual records for 556,237 adults diagnosed in 59 countries during 2000–2014 (CONCORD-3)
Background:
Survival is a key metric of the effectiveness of a health system in managing cancer. We set out to provide a comprehensive examination of worldwide variation and trends in survival from brain tumors in adults, by histology.
Methods:
We analyzed individual data for adults (15–99 years) diagnosed with a brain tumor (ICD-O-3 topography code C71) during 2000–2014, regardless of tumor behavior. Data underwent a 3-phase quality control as part of CONCORD-3. We estimated net survival for 11 histology groups, using the unbiased nonparametric Pohar Perme estimator.
Results:
The study included 556,237 adults. In 2010–2014, the global range in age-standardized 5-year net survival for the most common sub-types was broad: in the range 20%–38% for diffuse and anaplastic astrocytoma, from 4% to 17% for glioblastoma, and between 32% and 69% for oligodendroglioma. For patients with glioblastoma, the largest gains in survival occurred between 2000–2004 and 2005–2009. These improvements were more noticeable among adults diagnosed aged 40–70 years than among younger adults.
Conclusions:
To the best of our knowledge, this study provides the largest account to date of global trends in population-based survival for brain tumors by histology in adults. We have highlighted remarkable gains in 5-year survival from glioblastoma since 2005, providing large-scale empirical evidence on the uptake of chemoradiation at population level. Worldwide, survival improvements have been extensive, but some countries still lag behind. Our findings may help clinicians involved in national and international tumor pathway boards to promote initiatives aimed at more extensive implementation of clinical guidelines