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| 2. |
- Elmberg, Johan, et al.
(författare)
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Skedand
- 2007
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Annan publikation (övrigt vetenskapligt/konstnärligt)
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| 3. |
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| 4. |
- Hagströmer, M., et al.
(författare)
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Participation in organized weekly physical exercise in obese adolescents reduced daily physical activity
- 2009
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Ingår i: Acta Paediatr. - 1651-2227. ; 98:2, s. 352-4
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Tidskriftsartikel (refereegranskat)abstract
- AIM: The aim of this study was to describe the impact of organized weekly exercise for 13 weeks on aerobic fitness, objectively assessed habitual physical activity and body weight in obese adolescents. METHODS: After inclusion and diagnostic evaluation, the adolescents were randomized to either an exercise group or to a control group which lasted for 13 weeks and consisted of a variety of group exercise activities. Out of 47 adolescents 31 (66%) could be evaluated, 16 in the exercise group and 15 in the control group. RESULTS: After the intervention, the exercise group had decreased the daily time spent in moderate activity by 17 (32) min/day (p < 0.05), and the average intensity by 60 (96) counts/min (p < 0.05). A tendency for increased time spent in inactivity was found (37 min/day). No differences were seen in the control group for any of the variables measured. CONCLUSION: The exercise group showed, in contrast to expectations, a reduction in total daily physical activity with organized physical exercise compared to the control group. This may partly explain the failure of many intervention trials.
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| 5. |
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| 6. |
- Latorre-Margalef, Neus, et al.
(författare)
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Effects of influenza A virus infection on migrating mallard ducks
- 2009
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Ingår i: Proceedings of the Royal Society of London. Biological Sciences. - : The Royal Society. - 0962-8452 .- 1471-2954. ; 276:1659, s. 1029-1036
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Tidskriftsartikel (refereegranskat)abstract
- The natural reservoir of influenza A virus is waterfowl, particularly dabbling ducks (genus Anas). Although it has long been assumed that waterfowl are asymptomatic carriers of the virus, a recent study found that low-pathogenic avian influenza (LPAI) infection in Bewick's swans (Cygnus columbianus bewickii) negatively affected stopover time, body mass and feeding behaviour. In the present study, we investigated whether LPAI infection incurred ecological or physiological costs to migratory mallards (Anas platyrhynchos) in terms of body mass loss and staging time, and whether such costs could influence the likelihood for long-distance dispersal of the avian influenza virus by individual ducks. During the autumn migrations of 2002-2007, we collected faecal samples (n = 10 918) and biometric data from mallards captured and banded at Ottenby, a major staging site in a flyway connecting breeding and wintering areas of European waterfowl. Body mass was significantly lower in infected ducks than in uninfected ducks (mean difference almost 20 g over all groups), and the amount of virus shed by infected juveniles was negatively correlated with body mass. There was no general effect of infection on staging time, except for juveniles in September, in which birds that shed fewer viruses stayed shorter than birds that shed more viruses. LPAI infection did not affect speed or distance of subsequent migration. The data from recaptured individuals showed that the maximum duration of infection was on average 8.3 days (s.e. 0.5), with a mean minimum duration of virus shedding of only 3.1 days (s.e. 0.1). Shedding time decreased during the season, suggesting that mallards acquire transient immunity for LPAI infection. In conclusion, deteriorated body mass following infection was detected, but it remains to be seen whether this has more long-term fitness effects. The short virus shedding time suggests that individual mallards are less likely to spread the virus at continental or intercontinental scales.
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| 8. |
- Wallensten, Anders, et al.
(författare)
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Multiple gene segment reassortment between Eurasian and American lineages of influenza A virus (H6N2) in Guillemot (Uria aalge).
- 2005
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Ingår i: Archives of Virology. - : Springer Science and Business Media LLC. - 0304-8608 .- 1432-8798. ; 150:8, s. 1685-92
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Tidskriftsartikel (refereegranskat)abstract
- Guillemots banded in the northern Baltic Sea were screened for influenza A virus (IAV). Three out of 26 sampled birds tested positive by RT-PCR. Two of these were characterized as subtype H6N2. Phylogenetic analyses showed that five gene segments belonged to the American avian lineage of IAVs, whereas three gene segments belonged to the Eurasian lineage. Our findings indicate that avian IAVs may have a taxonomically wider reservoir spectrum than previously known and we present the first report of a chimeric avian IAV with genes of American and Eurasian origin in Europe.
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| 9. |
- Arzel, C., et al.
(författare)
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A flyway perspective of foraging activity in Eurasian Green-winged Teal, Anas crecca crecca
- 2007
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Ingår i: Canadian Journal of Zoology. - : National Research Council of Canada. - 0008-4301 .- 1480-3283. ; 85:1, s. 81-91
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Tidskriftsartikel (refereegranskat)abstract
- Time-activity budgets in the family Anatidae are available for the wintering and breeding periods. We present the first flyway-level study of foraging time in a long-distance migrant, the Eurasian Green-winged Teal, Anas crecca crecca L., 1758 ("Teal"). Behavioral data from early and late spring staging, breeding, and molting sites were collected with standardized protocols to explore differences between the,sexes, seasons, and diel patterns. Teal foraging activity was compared with that of the Mallard, Anas platyrhynchos L., 1758 and Northern Shoveler, Anas clypeata L., 1758, and the potential effects of duck density and predator-caused disturbance were explored. In early spring, foraging time was moderate (50.5%) and mostly nocturnal (45%). It increased dramatically in all three species at migration stopovers and during molt, mostly because of increased diurnal foraging, while nocturnal foraging remained fairly constant along the flyway. These patterns adhere to the "income breeding" strategy expected for this species. No differences between the sexes were recorded in either species studied. Teal foraging time was positively correlated with density of Teal and all ducks present, but negatively correlated with predator disturbance. Our study suggests that Teal, in addition to being income breeders, may also be considered as income migrants; they find the energy necessary to migrate at staging sites along the flyway.
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| 10. |
- Arzel, Céline, et al.
(författare)
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Ecology of spring-migrating Anatidae : a review
- 2006
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Ingår i: Journal of Ornithology = Journal fur Ornithologie. - : Springer Science and Business Media LLC. - 0021-8375. ; 147:2, s. 167-184
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Forskningsöversikt (refereegranskat)abstract
- Spring migration is generally considered as a crucial period of the year for many birds, not the least due to its supposed importance for subsequent breeding success. By reviewing the existing literature for Anatidae (ducks, geese, and swans), we show that little is known about their ecology in spring, although some goose species are exceptions. Another general pattern is that the ecology of Anatidae at staging sites is particularly neglected. Existing studies tend to focus on questions dealing with acquisition of nutrient reserves, whereas almost nothing has been published about stopover habitats, time use, microhabitat use, foraging behaviour, food availability, food limitation, diet selection, and interspecific relationships. Besides summarising present knowledge, we identify taxonomic groups and topics for which gaps of knowledge appear the most evident, thereby also highlighting research needs for the future.
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