| 1. |
- Alho, Jussi S., et al.
(författare)
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Increasing melanism along a latitudinal gradient in a widespread amphibian : local adaptation, ontogenic or environmental plasticity?
- 2010
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Ingår i: BMC Evolutionary Biology. - 1471-2148 .- 1471-2148. ; 10, s. 317-
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundThe thermal benefits of melanism in ectothermic animals are widely recognized, but relatively little is known about population differentiation in the degree of melanism along thermal gradients, and the relative contributions of genetic vs. environmental components into the level of melanism expressed. We investigated variation in the degree of melanism in the common frog (Rana temporaria; an active heliotherm thermoregulator) by comparing the degree of melanism (i) among twelve populations spanning over 1500 km long latitudinal gradient across the Scandinavian Peninsula and (ii) between two populations from latitudinal extremes subjected to larval temperature treatments in a common garden experiment.ResultsWe found that the degree of melanism increased steeply in the wild as a function of latitude. Comparison of the degree of population differentiation in melanism (PST) and neutral marker loci (FST) revealed that the PST > FST, indicating that the differences cannot be explained by random genetic drift alone. However, the latitudinal trend observed in the wild was not present in the common garden data, suggesting that the cline in nature is not attributable to direct genetic differences.ConclusionsAs straightforward local adaptation can be ruled out, the observed trend is likely to result from environment-driven phenotypic plasticity or ontogenetic plasticity coupled with population differences in age structure. In general, our results provide an example how phenotypic plasticity or even plain ontogeny can drive latitudinal clines and result in patterns perfectly matching the genetic differences expected under adaptive hypotheses.
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| 2. |
- Dessborn, Lisa, 1976-, et al.
(författare)
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Pike predation affects breeding success and habitat selection of ducks
- 2011
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Ingår i: Freshwater Biology. - : Wiley: 12 months. - 0046-5070 .- 1365-2427. ; 56:3, s. 579-589
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Tidskriftsartikel (refereegranskat)abstract
- 1. Fish and ducks often belong to the same local food web, and several studies indicate that there is a general negative effect of fish on breeding ducks. This pattern has so far been addressed mainly within the framework of competition for common invertebrate prey, while predation by large fish as a force behind settlement and abundance patterns in ducks remains largely unknown. This is the first study to address the effect of fish predation on breeding ducks, isolated from that of competition, and the first experiment to explore the ability of ducks to identify and avoid lakes with high risk of fish predation. 2. We used a before-after control-impact design and 11 naturally fishless lakes. Waterfowl on the lakes were surveyed during the breeding season of 2005. Large adult pike (Esox lucius) were added to two lakes in early spring 2008, and waterfowl surveys were repeated on all 11 lakes. 3. Pike introduction did not affect the number of pairs on lakes during the nesting season in any of three focal duck species (mallard Anas platyrhynchos, teal Anas crecca, and goldeneye Bucephala clangula). During the brood-rearing season, however, there was a decrease in duck days in teal and goldeneye in lakes with pike, with similar trends observed in mallard. The number of goldeneye ducklings was also significantly lower in lakes with pike. We were unable to determine whether the response was attributable to direct pike predation or to broods leaving experimental lakes, but in either case, our study demonstrates high fitness costs for ducks breeding on lakes with pike. 4. The apparent inability of nesting ducks to detect pike and the clear fitness implications may influence the annual recruitment of ducks on a larger scale as pike are both common and widespread. Vegetation complexity and food abundance are likely to be of overriding importance when breeding ducks are choosing a nesting site. As pike have a strong influence on breeding birds, relying on vegetation and cues of food abundance, while ignoring indicators of predation risk from fish, could lead to lakes with pike acting as an ecological trap.
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| 3. |
- Elmberg, Johan, et al.
(författare)
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Within-season sequential density dependence regulates breeding success in mallards Anas platyrhynchos
- 2005
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Ingår i: Oikos. - 0030-1299 .- 1600-0706. ; 108, s. 582-590
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Tidskriftsartikel (refereegranskat)abstract
- Density dependence in vital rates is a key issue in population ecology but remains largely unexplored experimentally. We studied breeding success, lake use, and prey availability in wild mallards Anas platyrhynchos on small nemoral lakes in a replicated, two-year cross-over experiment in which pair density was increased. The number of wild mallards that settled on lakes prior to introductions of extra pairs did not differ between control and introduction years. Introductions led to a lake-level reduction in the number of broods observed. However, the number of stage 2/ (almost fledged) ducklings did not differ between treatments, nor did lake utilization by nonbreeding adults, broods and ducklings. Prey resource availability differed greatly among lakes, but it did not correlate with breeding success. Partialling out the possible effect of food competition from wild adult nonbreeding mallards did not change this conclusion. Our study demonstrates sequential density dependence in breeding success; introductions caused a decrease in brood number, but despite fewer broods a similar number of nearly fledged ducklings were produced. We suggest that predation and/or lake change of broods soon after hatching created these patterns. We conclude that using a single and late measure of breeding success such as fledged birds can mask regulatory processes. Implications of density dependence and its relation to individual reproductive success are understood better if breeding success is decomposed into nest success, duckling survival and fledgling survival.
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| 4. |
- Gillman, Anna, et al.
(författare)
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Oseltamivir-Resistant Influenza A (H1N1) Virus Strain with an H274Y Mutation in Neuraminidase Persists without Drug Pressure in Infected Mallards
- 2015
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Ingår i: Applied and Environmental Microbiology. - : American Society for Microbiology. - 0099-2240 .- 1098-5336. ; 81:7, s. 2378-2383
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Tidskriftsartikel (refereegranskat)abstract
- Influenza A virus (IAV) has its natural reservoir in wild waterfowl and emerging human IAVs often contain gene segments from avian viruses. The active drug metabolite of oseltamivir (oseltamivir carboxylate (OC)), stockpiled as Tamiflu® for influenza pandemic preparedness, is not removed by conventional sewage treatment and has been detected in river water. There, it may there exert evolutionary pressure on avian IAV in waterfowl, resulting in development of resistant viral variants. A resistant avian IAV can circulate among wild birds only if resistance does not restrict viral fitness and if the resistant virus can persist without continuous drug pressure. In this in vivo Mallard (Anas platyrhynchos) study we tested if an OC-resistant avian IAV strain (A(H1N1)/NA-H274Y) could retain resistance while drug pressure was gradually removed. Successively infected Mallards were exposed to decreasing levels of OC, and fecal samples were analyzed for neuraminidase sequence and phenotypic resistance. No reversion to wild-type virus was observed during the experiment, which included 17 days of viral transmission in 10 ducks exposed to OC concentrations below resistance induction levels. We conclude that resistance in avian IAV, induced by OC exposure of the natural host, can persist in absence of the drug. Thus, there is a risk that human pathogenic IAVs that evolve from IAVs circulating among wild birds may contain resistance mutations. An oseltamivir resistant pandemic IAV would be a substantial public health threat. Therefore, our observations underscore the need for prudent oseltamivir use, upgraded sewage treatment and resistance surveillance of IAV in wild birds.
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| 5. |
- Hedenas, Henrik, et al.
(författare)
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Changes Versus Homeostasis in Alpine and Sub-Alpine Vegetation Over Three Decades in the Sub-Arctic
- 2012
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Ingår i: Ambio. - : Springer Verlag (Germany). - 0044-7447 .- 1654-7209. ; 41, s. 187-196
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Tidskriftsartikel (refereegranskat)abstract
- Plant species distributions are expected to shift and diversity is expected to decline as a result of global climate change, particularly in the Arctic where climate warming is amplified. We have recorded the changes in richness and abundance of vascular plants at Abisko, sub-Arctic Sweden, by re-sampling five studies consisting of seven datasets; one in the mountain birch forest and six at open sites. The oldest study was initiated in 1977–1979 and the latest in 1992. Total species number increased at all sites except for the birch forest site where richness decreased. We found no general pattern in how composition of vascular plants has changed over time. Three species, Calamagrostis lapponica, Carex vaginata and Salix reticulata, showed an overall increase in cover/frequency, while two Equisetum taxa decreased. Instead, we showed that the magnitude and direction of changes in species richness and composition differ among sites.
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| 6. |
- Jönsson, K. Ingemar, 1959-, et al.
(författare)
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Environmental adaptations : radiation tolerance
- 2019
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Ingår i: Water bears. - : Springer. - 9783319957012 - 9783319957029 ; , s. 311-330
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Several studies in different species have documented that tardigrades are among the most radiation-tolerant animals on Earth, surviving doses of ionizing radiation on the order of kGy. Both low-LET and high-LET radiation have been used with no apparent differences in the tolerance of the animals. Tolerance to ionizing radiation in tardigrades also seems to be independent of whether the animal has entered a dry anhydrobiotic state or is hydrated with normal activity. However, when exposed to UV radiation, desiccated tardigrades show a higher tolerance than hydrated animals. Recent studies in several species have shown that tardigrade embryos have considerably lower tolerance to ionizing radiation compared to adults, and embryos in the early stage of development are clearly more sensitive to radiation than those in the late developmental stage. The molecular mechanisms behind radiation tolerance in tardigrades are still largely unclear, but available evidence suggests that mechanisms related to both the avoidance of DNA damage and the repair of damage are involved.
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| 7. |
- Jönsson, K. Ingemar, 1959-, et al.
(författare)
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Sexual patterns of prebreeding energy reserves in the common frog Rana temporaria along a latitudinal gradient
- 2009
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Ingår i: Ecography. - : Wiley-Blackwell. - 0906-7590 .- 1600-0587. ; 32:5, s. 831-839
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Tidskriftsartikel (refereegranskat)abstract
- The ability to store energy is an important life history trait for organisms facing long periods without energy income, and in particular for capital breeders such as temperate zone amphibians, which rely on stored energy during reproduction. However, large scale comparative studies of energy stores in populations with different environmental constraints on energy allocation are scarce. We investigated energy storage patterns in spring (after hibernation and before reproduction) in eight common frog (Rana temporaria) populations exposed to different environmental conditions along a 1600 km latitudinal gradient across Scandinavia (range of annual activity period 3-7 months). Analyses of lean body weight (eviscerated body mass), weight of fat bodies, liver weight, and liver fat content, showed that (i) post-hibernation/pre-breeding energy stores increased with increasing latitude in both sexes, (ii) males generally had larger energy reserves than females and (iii) the difference in energy stores between sexes decreased towards the north. Larger energy reserves towards the north can serve as a buffer against less predictable and/or less benign weather conditions during the short activity period, and may also represent a risk-averse tactic connected with a more pronounced iteroparous life history. In females, the continuous and overlapping vitellogenic activity in the north may also demand more reserves in early spring. The general sexual difference could be a consequence of the fact that, at the time of our sampling, females had already invested their energy into reproduction in the given year (i.e. their eggs were already ovulated), while the males' main reproductive activities (e.g. calling, mate searching, sexual competition) occurred later in the season.
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| 8. |
- Jönsson, K. Ingemar, 1959-, et al.
(författare)
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The fate of the TARDIS offspring : no intergenerational effects of space exposure
- 2016
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Ingår i: Zoological Journal of the Linnean Society. - 0024-4082 .- 1096-3642. ; 178:4, s. 924-930
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Tidskriftsartikel (refereegranskat)abstract
- In September 2007 tardigrades became the first animal in history to survive the combined effect of exposure to space vacuum, cosmic radiation and ultraviolet radiation in low Earth orbit. The main results from this experiment were reported in 2008, but some of the results have remained unpublished. Here we report that descendant generations of space-exposed tardigrades of the species Milnesium tardigradum did not show reduced performance. This indicates that individual tardigrades that survived the exposure to environmental extremes in space, and were able to reproduce, did not transfer any damage to later generations. Repair of environmentally induced damage may therefore follow a ‘make or break’ rule, such that a damaged animal either fails to repair all damage and dies, or repairs damage successfully and leaves no mutations to descendants. We also report that two additional tardigrade species, Echiniscus testudo and Ramazzottius oberhaeuseri, showed high survival after exposure to space vacuum and cosmic radiation within the TARDIS experiment.
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| 9. |
- Nilsson, Charlotta, et al.
(författare)
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Element analysis of the eutardigrades Richtersius coronifer and Milnesium cf. asiaticum using Particle Induced X-ray Emission (PIXE)
- 2013
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Ingår i: Journal of limnology. - : Page Press. - 1129-5767 .- 1723-8633. ; 72:s1, s. 92-101
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Tidskriftsartikel (refereegranskat)abstract
- Semi-terrestrial tardigrades are well-known for their tolerance to a variety of environmental extremes, including desiccation, freezing and radiation. Despite several attempts to reveal the genetic and molecular mechanisms behind the resilience of tardigrades, it is still unknown how these animals are able to maintain the integrity of their cellular components under severe stress. Quantitative or qualitative changes in molecular compounds (e.g., carbohydrates, proteins) are expected, and have been the main line of research towards understanding the tolerance of tardigrades. In radiation tolerant bacteria, a tolerance mechanism based on manganese has been proposed. We evaluate this hypothesis in tardigrades and provide the first data on element composition in desiccated and non-desiccated specimens of two eutardigrade species, Richtersius coronifer and Milnesium cf. asiaticum. A focused 2 MeV proton microbeam was utilised to determine the elemental content, distributions and concentrations, using the ion beam analytical technique particle induced X-ray emission(PIXE). The presence of six elements – phosphorus, sulphur, chlorine, potassium, calcium and iron – were confirmed in all tardigrade specimens, at levels up to a few mg g–1. However, manganese was found in less than 10% of the analysed specimens, and in low amounts, thus our study provides no evidence for the manganese hypothesis. We also show that the distributions and/or concentrations of some elements differ between the two species as well as between the dehydrated and hydrated state. In particular, very low levels of iron were found in dehydrated M. cf. asiaticum. Our analysis shows that the PIXE technique is a useful tool for investigating questions on the distribution of elements both in dehydrated and hydrated tardigrades.
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| 10. |
- Söderquist, Pär
(författare)
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Large-scale releases of native species : the mallard as a predictive model system
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Human alteration of natural systems, and its consequences are of great concern and the impact on global ecosystems is one of the biggest threats that biodiversity stands before. Translocations of invasive species, as well as intraspecific contingents with non-native genotypes, whether they are deliberate or unintentional, are one such alteration and its consequences are continuously being assessed. The mallard (Anas platyrhynchos) is the most numerous and widespread duck in the world and a flagship in wetland conservation. It is also an important game species which is heavily restocked for hunting purposes, especially in Europe where over three million ducklings are released every year. Because of its hunted status, its abundance, and the number of released individuals, it can serve as a model species to study effects of releases, both for conservation and restocking for hunting, on wild populations. In this thesis the status of the mallard was assessed in the Nordic countries and the effects of releases on the wild populations were studied by mining historical ringing data, comparing morphology of present-day wild, farmed, and historical mallards, and analyzing phylogeography of wild and farmed mallards in Europe. The status of the mallard population in the Nordic countries are generally good, however, a joint effort of European countries is needed to monitor and manage the population. A significant difference between wild and farmed mallards concerning longevity, migration, bill morphology and genetic structure was also found, together with signs of cryptic introgression of farmed genotypes in the wild population with potential fitness reduction as a result. The effect is however limited by that only a fraction of released farmed mallards reach the breeding season due to low survival. A natural captive environment is crucial to keep individuals wild-like with high survival rates after release. However, with an introgression of potentially maladapted farmed genotypes leading to a reduction in fitness, a low survival of released mallards would favor the wild population. A legislative change regarding obligation to report numbers, provenance, and release sites of farmed mallard should be considered, together with practical solutions of ringing and genetic monitoring of released mallards.
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| 11. |
- Söderquist, Pär, et al.
(författare)
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Wild Mallards have more ”goose-like” bills than their ancestors
- 2015
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Ingår i: 4th Pan-European Duck Symposium, Hangö, Finland, 7-11/4, 2015. ; , s. 38-
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Konferensbidrag (refereegranskat)abstract
- Wild populations of the world’s most common dabbling duck, the Mallard (Anas platyrhynchos), run the risk of genetic introgression by farmed conspecifics released for hunting purposes. We tested whether bill morphology of free-living birds has changed since large-scale releases of farmed Mallards started. Three groups of Mallards from Sweden, Norway and Finland were compared: historical wild (before large-scale releases started), present-day wild, and present-day farmed. Higher density of bill lamellae was observed in historical wild Mallards (only males). Farmed Mallards had wider bills than present-day and historical wild ones. Present-day wild and farmed Mallards also had higher and shorter bills than historical wild Mallards. Present-day Mallards thus tend to have more ‘‘goose-like’’ bills (wider, higher, and shorter) than their ancestors. Our study suggests that surviving released Mallards affect morphological traits in wild population by introgression. We discuss how such anthropogenic impact may lead to a maladapted and genetically compromised wild Mallard population. Our study system has bearing on other taxa where large-scale releases of conspecifics with ‘alien genes’ may cause a cryptic invasive process that nevertheless has fitness consequences for individual birds.
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| 12. |
- Tolf, Conny, et al.
(författare)
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Individual variation in influenza A virus infection histories and long-term immune responses in mallards
- 2013
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 8:4, s. e61201-
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Tidskriftsartikel (refereegranskat)abstract
- Wild dabbling ducks (genus Anas) are the main reservoir for influenza A virus (IAV) in the Northern Hemisphere. Current understanding of disease dynamics and epidemiology in this virus-host system has primarily been based on populationlevel ,surveillance studies and infection experiments conducted in laboratory settings. Using a combined experimentalnatural approach with wild-strain captive mallards (Anas platyrhynchos), we monitored individual IAV infection histories and immunological responses of 10 birds over the course of 15 months. This is the first detailed study to track natural IAV infection histories over several seasons amongst the same individuals growing from juvenile to adults. The general trends in the infection histories of the monitored birds reflected seasonal variation in prevalence at the population level. However, within the study group there were significant differences between individuals in infection frequency as well as in short and long term anti-IAV antibody response. Further observations included individual variation in the number of infecting virus subtypes, and a strong tendency for long-lasting hemagglutinin-related homosubtypic immunity. Specifically, all infections in the second autumn, except one, were of different subtypes compared to the first autumn. The variation among birds concerning these epidemiologically important traits illustrates the necessity for IAV studies to move from the level of populations to examine individuals in order to further our understanding of IAV disease and epidemiology.
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| 13. |
- Björklund, Erland, et al.
(författare)
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MORPHEUS success story Segesholmsån river and Degeberga WWTP, Skåne, Sweden
- 2021
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- In the MORPHEUS project three Swedish Wastewater Treatment Plants (WWTPs) were investigated for their release of pharmaceuticals into the recipient. One of these was Degeberga WWTP which discharges its treated wastewater into the Segesholmsån river, ending in the Baltic Sea. Segesholmsån river has a length of 23 km and an average flow of roughly 0.6 m3/s (Figure 1).
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| 14. |
- Schill, Ralph O., et al.
(författare)
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Food of tardigrades : a case study to understand food choice, intake and digestion
- 2011
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Ingår i: Journal of Zoological Systematics and Evolutionary Research. - 0947-5745 .- 1439-0469. ; 49:Suppl. 1, s. 66-70
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Tidskriftsartikel (refereegranskat)abstract
- Mosses are an excellent habitat for tardigrades because of their ability to ensure a high humidity and to provide a rich food supply for both carnivorous and herbivorous species. Food choice can be correlated with the morphology of the buccal apparatus, and consequentially, their distribution is sometimes linked to food availability (nematodes, rotifers, plant cells, algae, yeast and bacteria). In many species, material containing chlorophyll is often observed in the midgut. However, little information has been available until now on the actual food preference of tardigrades. Since trophic interactions within soil food webs are difficult to study, here we use a polymerase chain reaction–based approach as a highly sensitive detection method. The study was carried out to investigate the presence of chlorophyll matter in the gut of active specimens, based on sequence analyses of the chloroplast ribulose 1,5-bisphosphate carboxylase/oxygenase large subunit (rbcL) gene from mosses and algae. The sequences found in the gut of Macrobiotus sapiens were derived from the moss families Pottiaceae and Erpodiaceae, in Macrobiotus persimilis and Echiniscus granulatus from the moss family Grimmiaceae, and in Richtersius coronifer from the green algae genus Trebouxia. Furthermore, we show the emission of green autofluorescence from the chloroplasts in the algae within the gut of tardigrades and followed the progress of digestion over a 48-h period. The autofluorescent emission level declined significantly, and after 2 days, the signal level was similar to the level of the starved control.
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| 15. |
- Strong, Emily A., et al.
(författare)
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Seeking greener pastures : crop selection by Greylag Geese (Anser anser) during the moulting season
- 2021
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Ingår i: Ornis Fennica. - : Finnish Omithological Soc. - 0030-5685. ; 98:1, s. 16-32
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Tidskriftsartikel (refereegranskat)abstract
- Over the last 40 years, many goose populations have recovered from historic lows and are now more numerous than ever. At the same time, geese have shifted from natural foraging habitats to securing most of their nutritional demands from agricultural fields, leading to crop damage and conflict with agriculture. We studied field use by Greylag Geese (Anser anser) in the agricultural landscape surrounding a main breeding and moulting lake in Sweden. From 2012 to 2016, weekly roadside surveys were conducted from May to July. Data were collected on goose numbers, crop type and sward height in agricultural fields. Using a compositional analysis, we demonstrate that Greylag Geese show a strong selection for ley and pasture fields compared to other crop types (rank order: ley/pasture > oat > barley > wheat > other crops). This selection was consistent across years and between pre- and post-moult. Aside from ley and pasture, no other croptypes were selected for, as they were used less than expected given their availability. Irrespective of crop type, geese foraged predominantly on short (0–10 cm) swards. The strong selection for ley and pasture may have been driven by higher nutritional quality of short, managed grass swards relative to other available foods. This suggests that during the summer grass fields may be more vulnerable to damage compared to other crop types. Our study provides a deeper understanding of the ecology of Greylag Geese, which may be used to inform management strategies focused on mitigating crop damage and alleviating conflict.
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| 16. |
- Åkesson, Susanne, et al.
(författare)
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Autumn migratory orientation and route choice in early and late dunlins Calidris alpina captured at a stopover site in Alaska
- 2021
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Ingår i: Biology open. - : The Company of Biologists Ltd. - 2046-6390. ; 10:4, s. 1-10
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Tidskriftsartikel (refereegranskat)abstract
- We investigated the migratory orientation of early and late captured dunlins, Calidris alpina, by recording their migratory activity in circular orientation cages during autumn at a staging site in southwest Alaska and performed route simulations to the wintering areas. Two races of dunlins breeding in Alaska have different wintering grounds in North America (Pacific Northwest), and East Asia. Dunlins caught early in autumn (presumably Calidris alpina pacifica) oriented towards their wintering areas (east-southeast; ESE) supporting the idea that they migrate nonstop over the Gulf of Alaska to the Pacific Northwest. We found no difference in orientation between adult and juveniles, nor between fat and lean birds or under clear and overcast skies demonstrating that age, energetic status and cloud cover did not affect the dunlins' migratory orientation. Later in autumn, we recorded orientation responses towards south-southwest suggesting arrival of the northern subspecies Calidris alpina arcticola at our site. Route simulations revealed multiple compass mechanisms were compatible with the initial direction of early dunlins wintering in the Pacific Northwest, and for late dunlins migrating to East Asia. Future high-resolution tracking would reveal routes, stopover use including local movements and possible course shifts during migration from Alaska to wintering sites on both sides of the north Pacific Ocean.
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| 17. |
- Beltran-Pardo, Eliana, et al.
(författare)
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Sequence analysis of the DNA-repair gene rad51 in the tardigrades Milnesium cf. tardigradum, Hypsibius dujardini and Macrobiotus cf. harmsworthi
- 2013
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Ingår i: Journal of limnology. - 1129-5767 .- 1723-8633. ; 72:s1, s. 80-91
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Tidskriftsartikel (refereegranskat)abstract
- Tardigrades are known for being resistant to extreme conditions, including tolerance to ionising and UV radiation in both the hydratedand the dehydrated state. It is known that these factors may cause damage to DNA. It has recently been shown that single and double DNAstrand breaks occur when tardigrades are maintained for a long time in the anhydrobiotic state. This may suggest that perhaps tardigrades rely on efficient DNA repair mechanisms. Among all proteins that comprise the DNA repair system, recombinases such as RecA or Rad51 have a very important function: DNA exchange activity. This enzyme is used in the homologous recombination and allows repair of thedamaged strand using homologous non-damaged strands as a template. In this study, Rad51 induction was evaluated by western blot in Milnesium cf. tardigradum, after exposure to gamma radiation. The Rad51 protein was highly induced by radiation, when compared to the control. The rad51 genes were searched in three tardigrades: Milnesium cf. tardigradum, Hypsibius dujardini and Macrobiotus cf. harmsworthi. The gene sequences were obtained by preparing and sequencing transcriptome libraries for H. dujardini and M. cf. harmsworthi and designing rad51 degenerate primers specific for M. cf. tardigradum. Comparison of Rad51 putative proteins from tardigrades with other organisms showed that they are highly similar to the corresponding sequence from the nematode Trichinella spiralis. A structure-based sequence alignment from tardigrades and other organisms revealed that putative Rad51 predicted proteins from tardigrades contain the expected motifs for these important recombinases. In a cladogram tree based on this alignment, tardigrades tend to cluster together suggesting that they have selective differences in these genes that make them diverge between species. Predicted Rad51 structures from tardigrades were also compared with crystalline structure of Rad51 in Saccharomyces cerevisiae. These results reveal that S. cerevisiae Rad51 structure is very similar to that of the three analysed tardigrades. On the other hand the predicted structure of Rad51 from M. cf. harmsworthi and H. dujardini are closer related to each other, than each of them to that of M. cf. tardigradum.
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| 18. |
- Jönsson, Ingemar, 1959-, et al.
(författare)
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Tolerance to gamma-irradiation in eggs of the tardigrade Richtersius coronifer depends on stage of development
- 2013
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Ingår i: Journal of limnology. - 1129-5767 .- 1723-8633. ; 72:s1, s. 73-79
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Tidskriftsartikel (refereegranskat)abstract
- Tardigrades are known as one of the most radiation tolerant animals on Earth, and several studies on tolerance in adult tardigrades have been published. In contrast, very few studies on radiation tolerance of embryonic stages have been reported. Here we report a study on tolerance to gamma irradiation in eggs of the eutardigrade Richtersius coronifer. Irradiation of eggs collected directly from a natural substrate (moss) showed a clear dose-response, with a steep decline in hatchability at doses up to 0.4 kGy followed by a relatively constant hatchability around 25% up to 2 kGy, and a decline to ca. 5% at 4 kGy above which no eggs hatched. Analysis of the time required for eggs to hatch after irradiation (residual development time) showed that hatching of eggs after exposure to high doses of gamma radiation was associated with short residual development time. Since short residual development time means that the egg was irradiated at a late developmental stage, this suggests that eggs were more tolerant to radiation late in development. This was also confirmed in another experiment in which stage of development at irradiation was controlled. No eggs irradiated at the early developmental stage hatched, and only one egg at middle stage hatched, while eggs irradiated in the late stage hatched at a rate indistinguishable from controls. This suggests that the eggs are more sensitive to radiation in the early stages of development, or that tolerance to radiation is acquired only late in development, shortly before the eggs hatch, hypotheses that are not mutually exclusive. Our study emphasizes the importance of considering specific cell cycle phases and developmental stages in studies of tolerance to radiation in tardigrades, and the potential importance of embryonic studies in revealing the mechanisms behind the radiation tolerance of tardigrades and other cryptobiotic animals.
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| 19. |
- Massa, Edoardo, et al.
(författare)
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Tardigrades of Kristianstads Vattenrike biosphere reserve with description of four new species from Sweden
- 2021
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Ingår i: Scientific Reports. - 2045-2322. ; 11:1, s. 1-19
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Tidskriftsartikel (refereegranskat)abstract
- Kristianstads Vattenrike Biosphere Reserve [KVBR] is a UNESCO designated area of Sweden possessing high biological value. Although several studies on tardigrades inhabiting Sweden havebeen performed, the KVBR area has been neglected. The current study investigates the tardigrade fauna of five areas of the biosphere reserve and includes 34 samples of different substrates analysed quantitatively and qualitatively. In total, 33 species of tardigrades were found in the samples, including 22 new records for the Skåne region, 15 new records for Sweden, and four species new to science. Mesobiotus emiliae sp. nov., Xerobiotus gretae sp. nov., Itaquascon magnussoni sp. nov., and Thulinius gustavi sp. nov. were described with an integrative approach (when possible) using morphological characters (light, electron scanning, and confocal laser scanning microscopies) and molecular markers (ITS2, 18S, 28S, cox1). A new protocol to increase morphological data was developed recovering mounted specimens within old slides for SEM analysis. Emended diagnoses for the genus Itaquascon and the transfer of Platicrista itaquasconoide to the genus Meplitumen are proposed. This study enriches the knowledge of the tardigrade biodiversity both within the KVBR and in Sweden and contributes to the rapidly increasing number of tardigrade species reported worldwide. The 33 species identified in the KVBR area represents 28% of all water bear species found in Sweden so far. The restricted study areas and limited number of samples collected suggests that the KVBR is very rich of tardigrades.
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| 20. |
- Abdel-Khalik, Jonas, et al.
(författare)
-
Incorporation of (14)C-cholesterol in human adrenal corticocarcinoma H295R cell line and online-radiodetection of produced (14)C-steroid hormone metabolites
- 2017
-
Ingår i: Journal of Pharmaceutical and Biomedical Analysis. - 0731-7085 .- 1873-264X. ; 145, s. 569-575
-
Tidskriftsartikel (refereegranskat)abstract
- This study demonstrates the addition of (14)C-cholesterol to the human cell line H295R will in-situ form radiolabeled steroid hormones allowing for new mechanistic and metabolic insights. The aim of the present study was to in-situ radiolabel steroid hormones from cell line-incorporated (14)C-cholesterol using the OECD guideline 456, H295R steroidogenesis in-vitro assay. Radiodetection of the steroid metabolites of the steroidogenic pathway allows for an improved understanding of the various enzymatic mechanisms involved without necessarily being dependent on quantification. Generated radiolabeled steroids were analyzed using HPLC hyphenated with a Flow Scintillation Analyzer (FSA). H295R cells were incubated with radiolabeled cholesterol and cell media were collected and prepared by solid phase extraction and analyzed with HPLC-FSA. For successful radiolabeling of the steroids in the steroidogenesis of H295R cells, radioactive cholesterol may potentially only need to be added just before the cells are incubated for 72h in well plates. Based on the obtained HPLC-FSA chromatograms, and confirmation of the observations by studies in the literature, a qualitative time profile for the production of steroid hormones was estimated. Multiple radiolabeled steroid hormones were identified by means of analytical standards and UV (ultraviolet) co-chromatography, though the elucidation of multiple metabolites remains unresolved. Although online radiodetection proved to suffer from suboptimal sensitivity, the concept of radiolabeling the steroidogenesis in H295R cells with (14)C-cholesterol and detecting the radiolabeled steroid hormones online was proved and may assist in further toxicological studies.
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| 21. |
- Abdel–Khalik, Jonas, et al.
(författare)
-
Simultaneous determination of endogenous steroid hormones in human and animal plasma and serum by liquid or gas chromatography coupled to tandem mass spectrometry
- 2013
-
Ingår i: Journal of chromatography. B. - 1570-0232 .- 1873-376X. ; 928:June, s. 59-77
-
Tidskriftsartikel (refereegranskat)abstract
- Analytical methodologies based on liquid or gas chromatography coupled to tandem mass spectrometry for the simultaneous determination of two or more endogenous steroid hormones in human and animal plasma and serum has received increased attention the last few years. Especially in the clinical setting steroid profiling is of major importance in disease diagnostics. This paper discusses recent findings in such multi-steroid hormone procedures published from 2001 to 2012. The aim was to elucidate possible relationships between chosen analytical technique and the obtained analyte sensitivity for endogenous steroid hormones. By evaluating the success, at which the currently applied techniques have been utilized, more general knowledge on the field is provided. Furthermore the evaluation provides directions in which future studies may be interesting to conduct.
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| 22. |
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| 23. |
- Arzel, C., et al.
(författare)
-
A flyway perspective of foraging activity in Eurasian Green-winged Teal, Anas crecca crecca
- 2007
-
Ingår i: Canadian Journal of Zoology. - 0008-4301 .- 1480-3283. ; 85:1, s. 81-91
-
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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| 24. |
- Arzel, Céline, et al.
(författare)
-
A flyway perspective on food resource abundance in a long-distance migrant, the Eurasian teal (Anas crecca)
- 2009
-
Ingår i: Journal of Ornithology = Journal fur Ornithologie. - 0021-8375 .- 1439-0361. ; 150:1, s. 61-73
-
Tidskriftsartikel (refereegranskat)abstract
- Two frequent assumptions about the evolution of long-distance migration in birds are that they travel long distances annually to reach food-rich areas for breeding, and that they time their migratory journey to be at staging sites when the latter provide the best feeding conditions. These assumptions have rarely been properly tested, and there is no study in which a species’ major food types have been measured by standardized methods throughout a flyway and over a large part of the year. We here present such data for Eurasian teal (Anas crecca), converted to a common energetic currency, and collected at wintering, spring staging and breeding sites. Teal did not time migration to maximize local food abundance; most birds left wintering and spring staging sites before a sharp increase in invertebrate food abundance occurred. On the other hand, hatching of ducklings coincided with a peak in invertebrate food abundance on boreal breeding lakes. Mean overall food abundance (invertebrates and seeds combined) did not differ between wintering sites in southern France and breeding sites in northern Sweden at the time of breeding. Our results are inconsistent with the hypothesis that long-distance migration in dabbling ducks has evolved because adult birds gain an immediate pay-off in increased food abundance by flying north in spring. However, our data confirm a selective advantage for breeding at higher latitudes, because hatching of ducklings may coincide with a peak in invertebrate emergence and because longer days may increase the duration of efficient foraging.
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| 25. |
- Arzel, Céline, et al.
(författare)
-
Are ducks able to adapt their migratory habits to environmental change?
- 2010
-
Ingår i: The abstract book. ; , s. 25-
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- In order to predict waterfowl population changes due to variation in climate conditions, and habitat availability it is necessary to precisely understand the mechanisms driving their annual cycle. This is particularly challenging in migratory birds as they encounter a huge variety of habitats along their migratory routes, and different factors might affect their demographic parameters at different stages of their life-cycle. In this perspective spring migration stands out as a crucial period. During spring migration birds need both to complete their migration and to prepare for subsequent reproduction. An understanding of long-term factors influencing the timing of breeding in migratory birds is particularly important in order to predict how they might respond to future environmental changes. Anatidae are particularly interesting to study as they offer a wide variety of migratory strategies. We discuss some of the factors that are likely to affect individual choices and thus play a role in the evolution of migration. Based on long-term data sets, collected over 30 years, in the Archipelago Sea, SW Finland, we also offer a first insight into the changes in their spring arrival and breeding success of ducks in relation to environmental conditions.
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| 26. |
- Arzel, Céline, et al.
(författare)
-
Average mass of seeds encountered by foraging dabbling ducks in western Europe
- 2007
-
Ingår i: Wildlife Biology. - 0909-6396 .- 1903-220X. - 0909-6396 ; 13:3, s. 328-336
-
Tidskriftsartikel (refereegranskat)abstract
- Many dabbling ducks Anas spp. are largely granivorous, consuming a variety of seeds chiefly from aquatic plants. To assess the relative value and carrying capacity of wetlands for dabbling ducks, species-specific information about seed mass is needed, but it is still largely missing or scattered in the literature. By combining weights of seeds collected in the field with a literature review, we provide a reference table for seed mass of 200 western European plant taxa frequently encountered by foraging dabbling ducks. Seeds collected in the field were sampled in microhabitats and at depths at which ducks were observed to forage, and study sites represent wintering, staging as well as breeding areas within a flyway in western Europe. When combined with calorimetric data, the present reference table will aid managers and scientists in assessing the importance of seed food resources at different sites and during different parts of the annual cycle.
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| 27. |
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| 28. |
- Arzel, Céline, et al.
(författare)
-
Does changing spring phenology affect short and long distance migratory waterfowl similarly?
- 2010
-
Ingår i: The abstract book. ; , s. 43-
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Among waterfowl, most ducks may be considered income breeders due to their small body size and their limited capacity to store energy. Therefore limited access to resources on their breeding grounds is likely to affect their breeding schedule and potentially output. At northern latitudes, ice break up dictates the access to the breeding lakes. An early ice break up allows for early access to the breeding site and its feeding resources, and potentially leading to higher breeding output than after a late ice break up. Short distance migrants are thus more likely to adapt to ice break up conditions than long distance migrants which have to cope with weather conditions en route and local resource accessibility along the migratory path. Using 20 years of data on breeding phenology and success of 3 species of ducks differing in their migratory strategy - Teal Anas crecca, Mallard Anas platyrhynchos and Common Goldeneye Bucephala clangula - in a watershed in Finland, we test the idea that variation in spring phenology affects the reproductive performance of duck species differently depending on their migration pattern.
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| 29. |
- Arzel, Céline, et al.
(författare)
-
Ecology of spring-migrating Anatidae : a review
- 2006
-
Ingår i: Journal of Ornithology = Journal fur Ornithologie. - 0021-8375 .- 1439-0361. - 0021-8375 ; 147:2, s. 167-184
-
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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| 30. |
- Arzel, Celiné, et al.
(författare)
-
Experimental functional response and inter-individual variation in foraging rate of teal (Anas crecca)
- 2007
-
Ingår i: Behavioural Processes. - 0376-6357 .- 1872-8308. - 0376-6357 ; 75:1, s. 66-71
-
Tidskriftsartikel (refereegranskat)abstract
- The functional response, i.e. the change in per capita food intake rate per time unit with changed food availability, is a widely used too] for understanding the ecology and behaviour of animals. However, waterfowl remain poorly explored in this context. In an aviary experiment we derived a functional response curve for teal (Anas crecca) foraging on rice (Oryza sativa) seeds. We found a linear relationship between intake rate and seed density, as expected for a filter-feeder. At high seed densities we found a threshold, above which intake rate still increased linearly but with a lower slope, possibly reflecting a switch from filter-feeding to a scooping foraging mode. The present study shows that food intake rate in teal is linearly related to food availability within the range of naturally occurring seed densities, a finding with major implications for management and conservation of wetland habitats.
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| 31. |
- Arzel, Céline, et al.
(författare)
-
Simändernas ekologi studeras närmare
- 2003
-
Ingår i: Vår fågelvärld. - 0042-2649. ; 62:4, s. 25-
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 32. |
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| 33. |
- Arzel, Céline, et al.
(författare)
-
Time use, foraging behavior and microhabitat use in a temporary guild of spring-staging dabbling ducks (Anas spp.)
- 2004
-
Ingår i: Ornis Fennica. - 0030-5685. - 0030-5685 ; 81:4, s. 157-168
-
Tidskriftsartikel (refereegranskat)abstract
- Dabbling ducks were studied on a eutrophic mid-flyway staging site in spring. Six species made up a temporary guild, in order of decreasing abundance they were: Teal (Anas crecca), Shoveler (A. clypeata), Mallard (A. platyrhynchos), Wigeon (A. penelope), Pintail (A. acuta), and Garganey (A. querquedula). Species richness and total abundance peaked around 20 April, whereas guild evenness was highest after the staging peak. Time use during the staging peak differed between the sexes in Mallard, but not in the other species. Mallard spent the least time foraging, whereas Shoveler and Teal foraged the most. Foraging behavior differed among species; i.e. Wigeon was mainly on land, Shoveler mainly fed from the water surface, whilst Mallard and Teal were more generalist. For the guild as a whole, shallow inshore areas were overused compared to offshore habitats. Microhabitat use of foraging birds differed among species; Pintail and Shoveler mainly fed in the offshore end of the habitat gradient, whereas Teal, Garganey, female Mallard, and especially Wigeon used shallow microhabitats. Teal and female Mallard had the highest overlap in microhabitat use, Shoveler and Wigeon had the least. Abundance of invertebrate prey was low during the staging peak, but increased sharply thereafter. This study indicates that eutrophic mid-flyway sites may offer less food to staging birds than do breeding lakes to which many of them are headed.
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| 34. |
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| 35. |
- Asplund, Maria E., et al.
(författare)
-
Water column dynamics of Vibrio in relation to phytoplankton community composition and environmental conditions in a tropical coastal area
- 2011
-
Ingår i: Environmental Microbiology. - 1462-2912 .- 1462-2920. ; 13:10, s. 2738-2751
-
Tidskriftsartikel (refereegranskat)abstract
- Vibrio abundance generally displays seasonal patterns. In temperate coastal areas, temperature and salinity influence Vibrio growth, whereas in tropical areas this pattern is not obvious. The present study assessed the dynamics of Vibrio in the Arabian Sea, 1-2 km off Mangalore on the south-west coast of India, during temporally separated periods. The two sampling periods were signified by oligotrophic conditions, and stable temperatures and salinity. Vibrio abundance was estimated by culture-independent techniques in relation to phytoplankton community composition and environmental variables. The results showed that the Vibrio density during December 2007 was 10- to 100-fold higher compared with the February-March 2008 period. High Vibrio abundance in December coincided with a diatom-dominated phytoplankton assemblage. A partial least squares (PLS) regression model indicated that diatom biomass was the primary predictor variable. Low nutrient levels suggested high water column turnover rate, which bacteria compensated for by using organic molecules leaking from phytoplankton. The abundance of potential Vibrio predators was low during both sampling periods; therefore it is suggested that resource supply from primary producers is more important than top-down control by predators.
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| 36. |
- Beery, Thomas, et al.
(författare)
-
From environmental connectedness to sustainable futures : topophilia and human affiliation with nature
- 2015
-
Ingår i: European Human Behaviour and Evolution Association Annual Conference, University of Helsinki, March 29-April 1, 2015. ; , s. 57-58
-
Konferensbidrag (refereegranskat)abstract
- The objective of this study is to explore the co-evolutionary foundation for place-based human affiliation with nonhuman nature, and its potential to support sustainable development at the local level. In particular, we analyse the Topophilia Hypothesis, an expansion of the Biophilia Hypothesis which includes also non-living elements in the environment. Methods: The study represents a multidisciplinary conceptual analysis of how biological selection and cultural learning may have interacted during human evolution to promote adaptive mechanisms for human affiliation with nonhuman nature via specific place attachment. Results and Conclusions: The Biophilia Hypothesis has been one of the most important theories of human connectedness with nature, suggesting a genetically based inclination for human affiliation with the biological world. The Topophilia Hypothesis has extended the ideas of Biophilia to incorporate a broader conception of nonhuman nature and a co-evolutionary theory of genetic response and cultural learning. It also puts more emphasis on affiliation processes with the local environment. We propose that nurturing potential topophilic tendencies may be a useful method to promote sustainable development at the local level, and ultimately at the global level. Tendencies of local affiliation may also have implications for multifunctional landscape management, an important area within sustainability research, and we provide some examples of successful landscape management with a strong component of local engagement. Since human affiliation with nonhuman nature is considered an important dimension of environmental concern and support for pro-environmental attitudes, the Topophilia Hypothesis may provide a fruitful ground for a discourse within which scholars from many scientific fields, including human evolution and humanistic geography, can participate.
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| 37. |
- Beery, Thomas, et al.
(författare)
-
From environmental connectedness to sustainable futures : topophilia and human affiliation with nature
- 2015
-
Ingår i: Sustainability. - 2071-1050. ; 7:7, s. 8837-8854
-
Tidskriftsartikel (refereegranskat)abstract
- Human affiliation with nonhuman nature is an important dimension of environmental concern and support for pro-environmental attitudes. A significant theory of human connectedness with nature, the Biophilia Hypothesis, suggests that there exists a genetically based inclination for human affiliation with the biological world. Both support and challenge to the Biophilia Hypothesis are abundant in the literature of environmental psychology. One response that both challenges and builds upon the Biophilia Hypothesis is the Topophilia Hypothesis. The Topophilia Hypothesis has extended the ideas of biophilia to incorporate a broader conception of nonhuman nature and a co-evolutionary theory of genetic response and cultural learning. While the Topophilia Hypothesis is a new idea, it is built upon long-standing scholarship from humanistic geography and theories in human evolution. The Topophilia Hypothesis expands previous theory and provides a multidisciplinary consideration of how biological selection and cultural learning may have interacted during human evolution to promote adaptive mechanisms for human affiliation with nonhuman nature via specific place attachment. Support for this possible co-evolutionary foundation for place-based human affiliation with nonhuman nature is explored from multiple vantage points. We raise the question of whether this affiliation may have implications for multifunctional landscape management. Ultimately, we propose that nurturing potential topophilic tendencies may be a useful method to promote sustainable efforts at the local level with implications for the global.
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| 38. |
- Beltrán-Pardo, Eliana, et al.
(författare)
-
Effects of ionizing radiation on embryos of the tardigrade Milnesium cf. tardigradum at different stages of development
- 2013
-
Ingår i: PLOS ONE. - 1932-6203. ; 8:9, s. e72098-
-
Tidskriftsartikel (refereegranskat)abstract
- Tardigrades represent one of the most desiccation and radiation tolerant animals on Earth, and several studies havedocumented their tolerance in the adult stage. Studies on tolerance during embryological stages are rare, but differentialeffects of desiccation and freezing on different developmental stages have been reported, as well as dose-dependent effectof gamma irradiation on tardigrade embryos. Here, we report a study evaluating the tolerance of eggs from theeutardigrade Milnesium cf. tardigradum to three doses of gamma radiation (50, 200 and 500 Gy) at the early, middle, andlate stage of development. We found that embryos of the middle and late developmental stages were tolerant to all doses,while eggs in the early developmental stage were tolerant only to a dose of 50 Gy, and showed a declining survival withhigher dose. We also observed a delay in development of irradiated eggs, suggesting that periods of DNA repair might havetaken place after irradiation induced damage. The delay was independent of dose for eggs irradiated in the middle and latestage, possibly indicating a fixed developmental schedule for repair after induced damage. These results show that thetolerance to radiation in tardigrade eggs changes in the course of their development. The mechanisms behind this patternare unknown, but may relate to changes in mitotic activities over the embryogenesis and/or to activation of responsemechanisms to damaged DNA in the course of development.
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| 39. |
- Betts, Bruce H, et al.
(författare)
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Phobos LIFE (Living Interplanetary Flight Experiment).
- 2019
-
Ingår i: Astrobiology. - 1531-1074 .- 1557-8070.
-
Tidskriftsartikel (refereegranskat)abstract
- The Planetary Society's Phobos Living Interplanetary Flight Experiment (Phobos LIFE) flew in the sample return capsule of the Russian Federal Space Agency's Phobos Grunt mission and was to have been a test of one aspect of the hypothesis that life can move between nearby planets within ejected rocks. Although the Phobos Grunt mission failed, we present here the scientific and engineering design and motivation of the Phobos LIFE experiment to assist with the scientific and engineering design of similar future experiments. Phobos LIFE flew selected organisms in a simulated meteoroid. The 34-month voyage would have been the first such test to occur in the high-radiation environment outside the protection of Earth's magnetosphere for more than a few days. The patented Phobos LIFE "biomodule" is an 88 g cylinder consisting of a titanium outer shell, several types of redundant seals, and 31 individual Delrin sample containers. Phobos LIFE contained 10 different organisms, representing all three domains of life, and one soil sample. The organisms are all very well characterized, most with sequenced genomes. Most are extremophiles, and most have flown in low Earth orbit. Upon return from space, the health and characteristics of organisms were to have been compared with controls that remained on Earth and have not yet been opened.
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| 40. |
-
Bioblitz i Arkelstorp 16-17 augusti 2019
- 2020
-
Samlingsverk (redaktörskap) (övrigt vetenskapligt/konstnärligt)abstract
- Arkelstorpsviken är den nordvästra delen av Oppmannasjön, som ären av Skånes största sjöar. Idén att genomföra en så kallad Bioblitzvid Arkelstorpsviken föddes under ett styrelsemöte i projektet "En viki Sjöriket Skåne" som är ett samarbete mellan Oppmanna Vånga Bygderåd och Högskolan Kristianstad. Projektets främsta syfte är att hitta en lösning på den kraftiga övergödningen i Arkelstorpsviken. Detta är ett ”Leader”-finansierat projekt, vilket innebär att stommen i projektetär lokal förankring. Det fanns röster i byn som kände att man gav området onödigt dåligt rykte genom att ständigt lyfta fram problemen med vattenstatusen i sjön. Under ett styrelsemöte 30 sep 2018 föddes iden att genom en Bioblitz lyfta fram de positiva värdena i och kring sjön. Den naturliga samarbetspartnern för detta projekt var forskningsmiljön MABH (Man & Biosphere Health) vid Högskolan Kristianstad,vars medlemmar tillsammans besitter en mycket bred biologisk kunskap.Med MABH i ryggen var alltså kompetensen säkrad för att genomföra en Bioblitz. Inbjudningar skickades ut till lokala naturorganisationerför att hitta ännu fler experter som kunde hjälpa till med särskilda artgrupper. Samtidigt jobbade man aktivt lokalt med att försöka engagera intresserad allmänhet. Inbjudningar och direktreklam skickades ut till samtliga hushåll med postadress Arkelstorp. I ett försök att synas genom mediebruset anordnades en tävling, som gick ut på att gissa antalet arter (taxa) som hittades under Bioblitzen. Två lokala företag ställde upp och första priset för den vuxna individ som gissade närmstvar en 3-rätters måltid på Bäckaskogs Slott. De yngre tävlande kunde vinna en kanotutflykt med familjen på Ivögården.
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| 41. |
- Brochet, Anne-Laure, et al.
(författare)
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Is diet segregation between dabbling ducks due to food partitioning? : a review of seasonal patterns in the Western Palearctic
- 2012
-
Ingår i: Journal of Zoology. - 0952-8369 .- 1469-7998. ; 286:3, s. 171-178
-
Tidskriftsartikel (refereegranskat)abstract
- Within the paradigm of resource-limited competition-structured communities, dabbling ducks (Anas spp.) have been used as a textbook example of how morphological differences, notably bill lamellar density and body length, may allow sympatric species to partition food and hence coexist. We reviewed all accessible diet studies from the Western Palearctic for three closely related dabbling duck species, mallard (Anas platyrhynchos), pintail (A.?acuta) and teal (A.?crecca), and present a comprehensive list of the food items (invertebrates, seeds, vegetative parts of plants) ingested. To assess the circumannual perspective of niche separation, we evaluated size distribution of ingested seeds among seasons and duck species. There was a significant difference among duck species in mean size and mass of ingested seeds, as well as in diet composition, with the largest seeds consumed by the largest species (mallard) with the coarsest bill filter apparatus (lamellae), and the smallest seeds by the smallest species (teal) with the finest bill lamellae. However, no effect of season was found, suggesting consistent diet segregation among species throughout the annual cycle of ducks and over large geographical areas. We argue that the patterns of food size separation between the three species are compatible with the idea of coexistence under interspecific competition.
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| 42. |
- Champagnon, Jocelyn, et al.
(författare)
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Changes in Mallard Anas platyrhynchos bill morphology after 30 years of supplemental stocking
- 2010
-
Ingår i: Bird Study. - 0006-3657 .- 1944-6705. ; 57:3, s. 344-351
-
Tidskriftsartikel (refereegranskat)abstract
- Capsule Massive releases of captive-reared Mallard for hunting purposes have been practiced for 30 years. During this period the number of lamellae per centimetre of bill length in wild Mallard populations has decreased. Aims Every year since the 1970s, several million captive Mallard have been released in Europe. This may lead to a spread of unnatural phenotypes into the wild. Nevertheless, the consequences of such introductions have not been examined. Methods Two widespread and common migratory ducks were studied: Mallard Anas platyrhynchos and Teal A. crecca. Mallard is the only duck species for which stocking programmes occur, and Teal served as a control. In a 'before-after' design, we compared duck bill lamellar density over the last 30 years. Results Lamellar density in Mallard, but not Teal, decreased. The observed 10% decrease occurred in the first (proximate) centimetre of the bill, the most crucial in terms of food filtration. Conclusions We hypothesize that the change in bill morphology was because of the propagation of captive Mallard into the wild: captive Mallard eat mainly large items, relaxing the natural selection pressure maintaining high lamellar density for sieving small prey in wild ducks.
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| 43. |
- Champagnon, Jocelyn, et al.
(författare)
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Consequences of massive bird releases for hunting purposes : mallard Anas platyrhynchos in the Camargue, Southern France
- 2009
-
Ingår i: Wildfowl. - 0954-6324 .- 2052-6458. ; :Special issue 2, s. 184-191
-
Tidskriftsartikel (refereegranskat)abstract
- The release of captive-reared fish and game animals into the wild is a common management practice in Europe and North America. In Europe, millions of reared birds are released each year yet the consequences of these release programmes have received little attention. This paper describes the massive introduction of Mallard Anas platyrhynchos, a native migrant species released into the wild to increase the size of hunted populations. It provides the rationale for current and forthcoming experiments aimed at determining the effects of the augmentation of Mallard stocks on wild population genotype and survival rates.
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| 44. |
- Champagnon, Jocelyn, et al.
(författare)
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Conspecifics can be aliens too : a review of effects of restocking practices in vertebrates
- 2012
-
Ingår i: Journal for Nature Conservation. - 1617-1381 .- 1618-1093. ; 20:4, s. 231-241
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Tidskriftsartikel (refereegranskat)abstract
- We review the indexed scientific literature (233 papers) dealing with ‘restocking’ of vertebrates, i.e. reinforcement of wild populations by release of individuals of the same species. We found evidence that restocking may have desired beneficial effects such as: increased genetic diversity and mitigation of Allee effects in small populations; increased size or even salvation of threatened populations; increased harvest opportunities; and, redirection of harvest pressure from wild to captive-bred individuals. However, restocking may also have negative effects like changes in behaviour, morphology, and demography in recipient populations, as well as enhancement of pathogen spread. Negative genetic effects on recipient populations include homogenisation, introduction of non-native genes, and loss of local adaptation. Research thus far is strongly biased towards birds and mammals, and geographically to Europe and North America. Restocking for conservation purposes has been studied more than that for harvest management, while the latter may be of far greater importance in terms of number of released individuals. Demographic and genetic effects have been studied more than effects on behaviour, which in turn have received more attention than effects on morphology and pathogen spread. There is a general tendency for research on restocking to be fragmented taxonomically and by biological sub-disciplines. Our review demonstrates that restocking practices may and do cause significant disruptions of natural patterns in wild recipient populations. It also highlights the diversity, frequency and extent of these activities, leading us to argue that restocking is an emerging conservation and ecosystem resilience issue of global significance. Based on this review we outline monitoring and research needs for the future. We also provide guidelines to practitioners in conservation, game management, fisheries, epidemiology and other fields involved in restocking of vertebrates, who are likely to benefit from merging their perspectives and adopting a more cross-taxonomical and interdisciplinary attitude when laying out future agendas for evaluation and policy-making in this field.
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| 45. |
- Champagnon, Jocelyn, et al.
(författare)
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Do stocking programs result in maladapted populations? : mallard bill morphology after 30 years of massive releases
- 2011
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Ingår i: Abstracts. ; , s. 31-
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Every year since the 1970s, several million captive Mallard have been released in Europe for hunting purposes. This may lead to a spread of unnatural phenotypes into the wild. Two widespread and common migratory ducks were studied: Mallard Anas platyrhynchos and Teal A. crecca. Mallard is the only duck species for which large-scale stocking programs occur in the region, and Teal hence serves as a control. In a « before-after » design, we compared duck bill lamellar density over the last thirty years. Lamellar density in Mallard, but not Teal, decreased. The observed 10 % decrease occurred in the first (proximate) centimetre of the bill, the most crucial in terms of food filtration. We hypothesize the observed change in bill morphology was due to the propagation of captive Mallard into the wild: captive Mallard mainly eat large items, relaxing the natural selection pressure maintaining high lamellar density for sieving small preys in wild ducks.
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| 46. |
- Champagnon, Jocelyn, et al.
(författare)
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Low survival after release into the wild : assessing “the burden of captivity” on Mallard physiology and behaviour
- 2012
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Ingår i: European Journal of Wildlife Research. - 1612-4642 .- 1439-0574. ; 58:1, s. 255-267
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Tidskriftsartikel (refereegranskat)abstract
- Captive-reared animals used in reinforcement programs are generally less likely to survive than wild conspecifics. Digestion efficiency and naive behaviour are two likely reasons for this pattern. The Mallard is a species with high adaptability to its environment and in which massive reinforcement programs are carried out. We studied physiological and behavioural factors potentially affecting body condition and survival of captive-reared Mallards after being released. Digestive system morphology and an index of body condition were compared among three groups: captive-reared birds remaining in a farm (control), captive-reared birds released into the wild as juveniles (released) and wild-born birds (wild). We also compared behaviour and diet of released vs. wild Mallards. Finally, we conducted a 1-year survival analysis of captive-reared birds after release in a hunting-free area. Gizzard weight was lower in control Mallards, but the size of other organs did not differ between controls and wild birds. The difference in gizzard weight between released and wild birds disappeared after some time in the wild. Diet analyses suggest that released Mallards show a greater preference than wild for anthropogenic food (waste grain, bait). Despite similar time-budgets, released Mallards never attained the body condition of wild birds. As a consequence, survival probability in released Mallards was low, especially when food provisioning was stopped and during harsh winter periods. We argue that the low survival of released Mallards likely has a physiological rather than a behavioural (foraging) origin. In any case, extremely few released birds live long enough to potentially enter the breeding population, even without hunting. In the context of massive releases presently carried out for hunting purposes, our study indicates a low likelihood for genetic introgression by captive-reared birds into the wild population.
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| 47. |
- Champagnon, Jocelyn, et al.
(författare)
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Survival probability and morphological adaptation of captive-reared Mallard Anasplatyrhynchos after release into the wild
- 2011
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Ingår i: Abstracts. ; , s. 16-
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Captive-reared animals released as part of reinforcement programmes are considered less likely to survive than their wild conspecifics. One of the possible causes for this is reduced digestion efficiency. We studied adaptation of the digestive system in Mallard, a species with high adaptability to its environment. Body condition and digestive organs were compared between three groups: captive-reared Mallards remaining in a game farm, captive-reared Mallards released into the wild as juveniles and wild Mallards. We also assessed difference in diet between released birds and wild birds, and conducted a one-year survival analysis of captive-reared birds released in a hunting-free area. Released Mallards had a smaller gizzard than wild birds, but there was no difference between captive-reared and wild Mallards in the size of others organs in the gastro-intestinal tract. Body condition of captive-reared Mallards was poorer than wild ones, and this was only partially improved after release. Survival probability of captive-reared Mallards was low, compared to documented survival of wild Mallards. In particular, high mortality occurred when additional food provisioning was stopped and during harsh winter periods. We argue that in spite of a viable digestive system, pre-release conditions experienced by captivereared ducks impeded restocking success. In the context of massive releases of this species for hunting purposes (several million birds per year in Europe), low survival due to a combination of high hunting pressure and poor condition could limit the number of farmed birds surviving to breed and thus limit introgression of "captive genes" into the wild population.
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| 48. |
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| 49. |
- Collin, Betty, 1976-, et al.
(författare)
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Experimental evaluation of survival of Vibrio parahaemolyticus in fertilized cold‐water sediment
- 2020
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Ingår i: Journal of Applied Microbiology. - 1364-5072 .- 1365-2672. ; 129:1, s. 75-84
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Tidskriftsartikel (refereegranskat)abstract
- Aims: This experimental study focuses on survival and consistence of Vibrio parahaemolyticus in cold‐water sediments and how increasing temperature and nutritional availability can affect growth. Methods and Results: A pathogenic strain of V. parahaemolyticus was inoculated in seawater microcosms containing bottom sediment. Gradually, during 14 days, the temperature was upregulated from 8 to 21°C. Culturable V. parahaemolyticus was only found in the sediment but declined over time and did not recover even after another 2 days at 37°C. Numbers of culturable bacteria matched the amount found by q‐PCR indicating that they did not enter a dormant state, contrary to those in the water layer. After adding decaying phytoplankton as fertilizer to the microcosms of 8 and 21°C for 7 and 14 days, the culturability of the bacteria increased significantly in the sediments at both temperatures and durations of exposure. Conclusion: The study showed that V. parahaemolyticus can stay viable in cold‐water sediment and growth was stimulated by fertilizers rather than by temperature. Significance and Impact of the Study: Vibrio parahaemolyticus is a common cause of seafood‐borne gastroenteritis and is today recognized in connection to increasing ocean temperature. The results indicate that this pathogen should be considered a risk in well‐fertilized environments, such as aquacultures, even during cold periods.
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| 50. |
- Collin, Betty, 1976-, et al.
(författare)
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Faecal contaminants in edible bivalves from Maputo Bay, Mozambique : seasonal distribution, pathogenesis and antibiotic resistance
- 2008
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Ingår i: Open Nutrition Journal. - 1874-2882. ; 2, s. 86-93
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Tidskriftsartikel (refereegranskat)abstract
- In Maputo, Mozambique marine bivalves considerably contribute to the diet of the population. This study aimed to investigate seasonal distribution of Escherichia coli and Salmonella in clams from Maputo Bay, and examine their pathogenesis and antibiotic-resistant patterns. Standard multiple tube method revealed that the concentration of coliforms in all samples exceeded the limit for direct consumption, according to EU standards. Thirty-eight percent of the samples contained >60,000 MPN per 100 gram flesh. The occurrence of E. coli did not differ significantly due to season, while Salmonella was present in 100% of the samples during the rainy period and only in 30% during the dry. Multiplex polymerase chain reaction showed that 45% of E. coli isolates were positive for the virulent indicator gene fimA. The Salmonella isolates were identified as S. enterica serovar Typhimurium. Among other isolated coliformic Enterobacteriaceae, Shigella sp. (specie), which in low doses can cause severe gastrointestinal infections, was identified. Antimicrobial susceptibility, recorded by the disk diffusion method, showed resistance to the most commonly used antibiotics. This high levels of faecal contaminants in the clams points out the need for risk assessment and sanitary improvements.
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