| 1. |
- Hedlund, Johanna, 1982-
(författare)
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Climate change effects on migratory birds and on the ecology and behaviour of the willow warbler (Phylloscopus trochilus)
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Recent global climate change is influencing the behaviour and ecology of species worldwide. Birds are typical systems to study in this context, as they are often migratory and thus subjected to a variety of environmental effects. This thesis employs the use of long-term ringing records, field observations, historical maps and historical volunteer observations with the aim of describing behavioural and ecological responses of birds to the current environmental change. An investigation into the spring arrival, reproduction and autumn departure in willow warblers (Phylloscopus trochilus) breeding at a southern study site in Sweden (65°N 18°E) showed that all three phenological events had advanced in parallel. Thus birds arrive earlier, start breeding earlier and leave Sweden earlier, with the breeding period staying the same in length. By teasing apart the migratory responses of different individuals, it became clear that particularly early arriving males and early departing juveniles had advanced migration. However, willow warblers migrating past a northern study site in Sweden (65°N 23°E) displayed no change in autumn departure. When migration in the two regionally separate populations were analyzed in relation to climatic variables, the results indicated that foremost a combined effect of growing season onset and the North Atlantic Oscillation influenced migratory timing, and only in individuals that had advanced migration. As growing season onset had advanced at both regions, but only elicited migratory change in southern willow warblers, it is proposed that intra-specific difference between populations prepare them differently to climate change. Willow warblers breeding at northern latitudes were also displaying absence of an otherwise common behaviour of the species: philopatry. It is suggested that the climate induced change in onset of the growing season, coupled with an increase in available territories, could have enabled a southern influx of dispersal-prone birds adopting a less philopatric breeding behaviour. Availability of territories was also studied in southern Sweden, in relation to 100 years of land use change and future climate change effects on forestry. The mass-conversion of grazed forest into coniferous sylvicultures that has occurred in Sweden 1900-2013 was shown to have negatively affected territory availability for willow warblers. The second most common bird species in Sweden, the chaffinch (Fringilla coelebs), was however shown to be largely unaffected. In a future scenario where rising temperatures will increase growth rates of trees, harvest rotation will be faster and both sylvicultures and logged areas will increase in coverage, favouring both species. Thus commonness in terms of landscape and species occurrence has altered historically and is dynamically linked. Historic perspectives were also applied to observations of spring arrival of 14 migratory bird species. A relative comparison of two data sets, collected over 140 years, revealed that short-distance migrants have changed their spring arrival more than long-distance migrants in southern Sweden. In conclusion, the results of this thesis provide insights into climate change effects on avian behaviour and ecology, document unique observations and contribute with a great spectrum of knowledge, from exact details on responses by individual birds, through long-term changes in populations to historical perspectives on shifts in entire landscapes
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| 2. |
- Hedlund, Johanna S. U., et al.
(författare)
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Long-term phenological shifts and intra-specific differences in migratory change in the willow warbler Phylloscopus trochilus
- 2015
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Ingår i: Journal of Avian Biology. - : Wiley. - 0908-8857 .- 1600-048X. ; 46:1, s. 97-106
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Tidskriftsartikel (refereegranskat)abstract
- Climate change can influence many aspects of avian phenology and especially migratory shifts and changes in breeding onset receive much research interest in this context. However, changes in these different life-cycle events in birds are often investigated separately and by means of ringing records of mixed populations. In this long-term study on the willow warbler Phylloscopus trochilus, we investigated timing of spring and autumn migration in conjunction with timing of breeding. We made distinction among individuals with regard to age, sex, juvenile origin and migratory phase. The data set comprised 22-yr of ringing records and two temporally separated data sets of egg-laying dates and arrival of the breeding population close to the ringing site. The results reveal an overall advancement consistent in most, but not all, phenological events. During spring migration, early and median passage of males and females became earlier by between 4.4 to 6.3 d and median egg-laying dates became earlier by 5 d. Male arrival advanced more, which may lead to an increase in the degree of protandry in the future. Among breeding individuals, only female arrival advanced in timing. In autumn, adults and locally hatched juvenile females did not advanced median passage, but locally hatched juvenile males appeared 4.2 d earlier. Migrating juvenile males and females advanced passage both in early and median migratory phase by between 8.4 to 10.1 d. The dissimilarities in the response between birds of different age, sex and migratory phase emphasize that environmental change may elicit intra-specific selection pressures. The overall consistency of the phenological change in spring, autumn and egg-laying, coupled with the unchanged number of days between median spring and autumn migration in adults, indicate that the breeding area residence has advanced seasonally but remained temporally constant.
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| 3. |
- Hedlund, Johanna S. U., et al.
(författare)
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Point of no return – absence of returning birds in the otherwise philopatric willow warbler Phylloscopus trochilus
- 2017
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Ingår i: Journal of Avian Biology. - : Wiley. - 0908-8857 .- 1600-048X. ; 48:3, s. 399-406
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Tidskriftsartikel (refereegranskat)abstract
- The return of individual birds to a specific area in successional years, i.e. philopatry, is a remarkable behavioural trait. Here we report on the remarkably reversed: the complete absence of returning individuals of a migratory passerine with otherwise pronounced philopatry. At a high latitude study site in Abisko (68°32ʹN, 18°80ʹE) in northern Sweden none of the banded adult willow warblers Phylloscopus trochilus returned to breed 2011–2014. This is in stark contrast to all other reports in the literature and also to our two southern study sites (at 56°56ʹN, 18°10ʹE and at 58°94ʹN, 17°14ʹE) where 18–38% of adults returned. We investigated this aberrant pattern found in Abisko by analysing three parameters known to influence philopatry; nest predation, breeding success and breeding density, and predicted that absence of philopatry should co-occur with low breeding success, low breeding density and/or high nest predation. The results did not corroborate this, except that breeding density was lower at Abisko (49–71 pairs km–2) than at the southern sites (106 pairs km–2, 101 pairs km–2). Instead, we suggest the hypothesis that the absence of philopatry is caused by an influx of southern, dispersal-prone individuals deploying another breeding strategy and that this intra-specific range expansion is enabled by milder climate and low population density.
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| 4. |
- Larsson, Karin, et al.
(författare)
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Biological characterization of new inhibitors of microsomal PGE synthase-1 in preclinical models of inflammation and vascular tone
- 2019
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Ingår i: British Journal of Pharmacology. - : Wiley. - 0007-1188 .- 1476-5381. ; 176:24, s. 4625-4638
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Tidskriftsartikel (refereegranskat)abstract
- Background and Purpose Microsomal PGE synthase-1 (mPGES-1), the inducible synthase that catalyses the terminal step in PGE(2) biosynthesis, is of high interest as therapeutic target to treat inflammation. Inhibition of mPGES-1 is suggested to be safer than traditional NSAIDs, and recent data demonstrate anti-constrictive effects on vascular tone, indicating new therapeutic opportunities. However, there is a lack of potent mPGES-1 inhibitors lacking interspecies differences for conducting in vivo studies in relevant preclinical disease models. Experimental Approach Potency was determined based on the reduction of PGE(2) formation in recombinant enzyme assays, cellular assay, human whole blood assay, and air pouch mouse model. Anti-inflammatory properties were assessed by acute paw swelling in a paw oedema rat model. Effect on vascular tone was determined with human ex vivo wire myography. Key Results We report five new mPGES-1 inhibitors (named 934, 117, 118, 322, and 323) that selectively inhibit recombinant human and rat mPGES-1 with IC50 values of 10-29 and 67-250 nM respectively. The compounds inhibited PGE(2) production in a cellular assay (IC50 values 0.15-0.82 mu M) and in a human whole blood assay (IC50 values 3.3-8.7 mu M). Moreover, the compounds blocked PGE(2) formation in an air pouch mouse model and reduced acute paw swelling in a paw oedema rat model. Human ex vivo wire myography analysis showed reduced adrenergic vasoconstriction after incubation with the compounds. Conclusion and Implications These mPGES-1 inhibitors can be used as refined tools in further investigations of the role of mPGES-1 in inflammation and microvascular disease.
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| 5. |
- Lindskog, Magnus, et al.
(författare)
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Overall survival in Swedish patients with renal cell carcinoma treated in the period 2002 to 2012: Update of the RENCOMP study with subgroup analysis of the synchronous metastatic and elderly populations
- 2017
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Ingår i: Urologic Oncology-Seminars and Original Investigations. - : Elsevier BV. - 1078-1439 .- 1873-2496. ; 35:9, s. 541.e15-541.e22
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Tidskriftsartikel (refereegranskat)abstract
- Background: This retrospective study investigated overall survival (OS) and factors influencing OS in Swedish patients with metastatic renal cell carcinoma (mRCC) during the pre- (2002-2005), early (2006-2008), and late (2009-2012) targeted therapy (TT) era. Methods: Three national Swedish registries identified patients with mRCC. Median OS was estimated using the Kaplan-Meier method. Multivariate analysis was performed using Cox proportional hazards regression. Subgroup analysis was conducted for patients with synchronous metastases (Ml) and the elderly (aged >= 75 y). Results: A total of 4,217 patients with mRCC were identified, including 1,533 patients with Ml and 1,275 elderly patients. For patients with mRCC diagnosed in 2002 to 2005, 2006 to 2008, and 2009 to 2012, median OS was 10.0, 13.0, and 18.0 months. Similarly, median OS improved in the M1 and elderly populations. Elderly patients were less likely to be prescribed TT (>= 75 vs. <75 y): 18.3 vs. 63.5% (in 2006-2008) and 28.6% vs. 55.9% (in 2009-2012). Diagnosis of mRCC in 2009 to 2012, nephrectomy and TT prescription were associated with improved OS in the total mRCC, Ml, and elderly populations. Conclusion: This real-world study showed continued significant improvement in mRCC OS during the late TT era, including in Ml and elderly populations. TT should be considered for all patients with mRCC based on tolerability, regardless of age. (C) 2017 Elsevier Inc. All rights reserved.
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| 6. |
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| 7. |
- Redig, Josefine, et al.
(författare)
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Real-world cost-effectiveness of targeted therapy in metastatic renal cell carcinoma in Sweden : a population-based retrospective analysis
- 2019
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Ingår i: Cancer Management and Research. - Auckland : Dove medical press. - 1179-1322. ; 11, s. 1289-1297
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To explore cost-effectiveness of targeted therapies (TTs) in the treatment of metastatic renal cell carcinoma (mRCC) in a real-world context using a nationwide population-based approach.Methods: Data on patients diagnosed with mRCC between 2002 and 2012 were extracted from Swedish national health data registers. To facilitate comparisons of patients diagnosed before and after TT introduction to the market, three cohorts were derived: pre-TT introduction (preTT), patients diagnosed 2002-2005; early TT introduction (TTi), patients diagnosed 2006-2008; and late TT introduction (TTii), which was limited to patients diagnosed 2009-2010 to ensure availability of total health care resource utilization (HCRU) data. Patients were followed until end of 2012. The value of TTs across cohorts was estimated using mean HCRU costs per life-year (LY) gained. Data on HCRU were obtained through national health registers for dispensed medication and inpatient and outpatient care, and the associated costs were estimated using the Lin method to account for censoring. LYs gained were defined as the difference in mean survival over the study period.Results: The preTT, TTi, and TTii cohorts consisted of 1,366, 1,158, and 806 patients, respectively. Mean survival in years from mRCC diagnosis was 1.45 in the preTT cohort, 1.62 in the TTi cohort, and 1.83 in the TTii cohort. The respective mean total HCRU cost per patient over the study period was US$16,894, US$29,922, and US$30,037. The cost per LY gained per cohort was US$78,656 for TTi vs preTT, US$34,132 for TTii vs preTT, and US$523 for TTii vs TTi.Conclusion: Given common willingness-to-pay per LY gained thresholds, this study in a real-world population suggests the use of TTs in the Swedish mRCC population is increasingly cost-effective over time.
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| 8. |
- Stach, Robert, 1971-, et al.
(författare)
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Migration routes and timing in a bird wintering in South Asia, the Common Rosefinch Carpodacus erythrinus
- 2016
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Ingår i: Journal of Ornithology. - : Springer Science and Business Media LLC. - 2193-7192 .- 2193-7206. ; 157, s. 671-679
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Tidskriftsartikel (refereegranskat)abstract
- Only few bird species from Western Europe migrate eastward to wintering areas in South Asia, and little is known about this migratory flyway. The Common Rosefinch has in the past century expanded its breeding range westward to include Western Europe and migrate along this flyway to wintering sites in South Asia. This is the first study describing the migration routes of Common Rosefinches between Europe and Asia in detail, revealed by light level geolocators. The rosefinches showed loop-migration with more northerly routes in autumn than in spring, possibly in order to shorten the flight over the Central Asian deserts, which are very inhospitable at this time of the year. In spring the deserts are less dry and richer in vegetation, which may have supported the more southerly routes. During autumn migration the birds used several staging sites in Central Asia for prolonged periods. Although the birds passed over mountain regions at this time, which potentially act as barriers to them, the length of the stops seem unrealistically long for only fuel deposition. Instead, this suggests that the birds temporarily suspended migration to take advantage of abundant and predictable food sources in this region. During spring migration the birds made a few longer stops while still in north India or Central Asia, before migrating at fast speeds towards the breeding grounds. The birds covered 4–5000 km with only very short stopovers and thus most of the fuel used on spring migration must have been accumulated in Asia. Our results thus indicate that Central Asia, and north India, are important staging areas for this species in both autumn and spring. During winter, birds used two sites located several hundred kilometres apart, and relocation was probably a response to local food availability.
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| 9. |
- Stach, Robert, 1971-
(författare)
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Migratory routes and stopover behaviour in avian migration
- 2016
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Migratory birds, some small and light weight as matchboxes, engage in seasonal inter-continental journeys in order to take advantage of the long summer days and abundance of food at northern latitudes to breed and raise their young, and then escape the harsh winters by migrating to lower latitudes. This thesis deals with two important aspects of migration, the routes taken during migration and the birds’ behaviour at stopovers. The migratory routes are for many species unknown, whole or in part, and this is especially true for species that migrate nocturnally. At stopovers birds replenish fuel reserves that powers migratory flight, and studying how birds utilise stopovers is important in order to understand how migration is organised. In this thesis I have used modern tracking technology to study both continental wide movements of thrush nightingales (Luscinia luscinia) and common rosefinches (Carpodacus erythrinus) using small light-level geolocators, and smaller scale movements at a single stopover site of garden warblers (Sylvia borin) using miniature radio-transmitters. I have also studied the fuelling behaviour of garden warblers during autumn migration in the field and in the lab, and great reed warblers (Acrocephalus arundinaceus) at a stopover site on Crete during spring migration after the Sahara crossing. The thesis discusses the significance of several aspects of migration shown by the birds that would have been very difficult to detect without the aid of modern tracking technology, such as loop migration, prolonged stops during migration, multiple wintering sites, and nocturnal relocations at stopover sites. Studies carried out at stopover sites also show that garden warblers and great reed warblers can attain large fuel loads even at sites where they have no barrier to cross and this might be a result of good foraging conditions. The thesis also highlights the importance of combining different techniques when studying stopover behaviour to get reliable estimates on stopover durations and fuel deposition rates as well as the importance of choosing sites preferred by birds when planning stopover studies.
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| 10. |
- Stach, Robert, 1971-, et al.
(författare)
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Wide ranging stopover movements and substantial fuelling in first year garden warblers at a northern stopover site
- 2015
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Ingår i: Journal of Avian Biology. - : Wiley. - 0908-8857 .- 1600-048X. ; 46:3, s. 315-322
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Tidskriftsartikel (refereegranskat)abstract
- Migratory birds use stopovers to replenish their fuel reserves and they generally spend more time at stopover sites than theydo in actual fl ight. When arriving at a new stopover site birds may need to search extensively to fi nd a suitable feeding areaand this search and settling period may aff ect the duration of stopover. Stopover behaviour can thus have profound eff ectson the migratory programme and studies on stopover behaviour are important to understand migratory strategies. Wefollowed 51 fi rst-year garden warblers Sylvia borin with radio-transmitters at an autumn stopover site on the island ofGotland in southern Sweden. Our aim was to determine the distance birds relocated from the coastal capture site whensearching for an area to settle in, and also to establish the duration of stopover and put it in relation to refuelling rate byrecapturing a subset of the radio-tracked individuals. Sixteen birds made an extended stopover ( 2 d), relocated inlandfrom the capture site and settled on average 5.6 km from the capture site, with the longest recorded relocation being fourteenkilometres. Birds that relocated nocturnally settled in areas further away than birds that relocated diurnally. Th irteenbirds that continued migration after a short stop carried larger fuel stores than birds that stopped over longer and theyremained close to the capture site until departure. Th ree birds were re-trapped and showed high fuelling rates, between0.3 and 1.1 g d 1 . Th ey left the stopover site with fuel loads between 40 – 56 percent of lean body mass, which possiblywould have allowed them to reach the Mediterranean area without additional refuelling stops.
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