| 1. |
- Hansson, L-A, et al.
(författare)
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A synthesis of animal movement across scales
- 2014
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Ingår i: Animal Movement Across Scales. - : Oxford University Press. - 9780199677184 ; , s. 259-267
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Bokkapitel (refereegranskat)abstract
- This chapter aims at synthesizing the knowledge presented in the chapters of the book’s three sections by addressing evolutionary compromises, dispersal, gene flow, and assisted movements. How climate change and other environmental changes at different scales may affect animal movement, migration, and dispersal in the future are also summarized here. Moreover, how the different senses are utilized for navigation and orientation and how these may lead to different movement and migration patterns are also discussed. Finally, how the recent technical revolution has affected animal movement research is addressed and the view on future perspectives of animal movement research is also provided.
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| 2. |
- Lindström, Åke, et al.
(författare)
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Birds doing it the octopus way : fright moulting and distraction of predators
- 1988
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Ingår i: Ornis Scandinavica. - : JSTOR. - 0030-5693. ; 19:2, s. 165-166
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Tidskriftsartikel (refereegranskat)abstract
- "Fright moulting" has been recorded in several orders of birds and interpreted as a way of escaping a predator when already caught. Two observations suggest that the behaviour may have another function, viz. when an aerial predator chases the prey. By shedding body feathers in the air the bird creates a cloud behind it; this might confuse the predator in the same way as the ink of octopuses confuse their predators.
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| 3. |
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| 4. |
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| 5. |
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| 6. |
- Andersson, Arne, et al.
(författare)
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Ottenby fågelstation : Årsrapport 1999
- 1999
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Decenniets, seklets och milleniets sista år blev ett år av stora förändringar vid Ottenby fågelstation. Deföregående tre-fyra åren hade präglats av mycket dålig ekonomi och därtill personalproblem. Under 1998blev situationen akut. Som ett första led i att förbättra situationen ombildades Ottenbykommittén (avSveriges Ornitologiska Förening satt att sköta fågelstationen) under hösten 1998. Den störstaförändringen blev sedan att Jan Pettersson, platschef sedan 1978, sades upp. Därtill kom uppsägning,pensionering, dödsfall (se nedan) och sedan tidigare överflyttade tjänster till OFAB, vilket innebar detatt den “fast” anställda personalstyrkan, som 1992 var 7 personer, reducerades till noll!Ottenbykommittén har nu fått en mycket mer aktiv roll i stationens arbete. Olika verksamhetsdelar haridentifierats och ledamöterna har getts olika ansvarsområden.Kommittén bestod under året av :Åke Lindström (ordförande)Christian Hjort (sekreterare, utlandsverksamheten)Dennis Kraft (ekonomi)Arne Andersson (datafrågor)Dennis Hasselquist (samordning av ansökningar)Anders Hedenström (forskningssamordnare)Niclas Jonzén (personal)Lars Lindell (SOF:s styrelse).Aktiviteterna inom dessa olika områden redovisas nedan och här skallbara de generella linjerna i arbetet läggas fram.Tvivelsutan förbättrades arbetsklimatet för den ideellt arbetandepersonalen på fågelstationen och glädjande nog var tillströmningen storav arbetsvilliga ungdomar. Stationen blev på många sätt öppnare, inteminst mot fågelskådarleden. Fler personer besökte stationen och pådetta sätt kan många fler känna sig delaktiga och trivas. Nackdelen äratt det rent praktiskt blir svårare att driva verksamheten med mångamänniskor närvarande och relativt stor omsättning på personer.Genom mycket hård åtstramning på utgiftssidan kunde ett förväntat rejält underskott i budgeten vändastill en liten vinst. Alla inblandade skall ha stor ära av detta eftersom både stora som små uppoffringarkrävts för att styra ekonomin rätt. Den lilla vinsten användes till att börja täcka det underskott somunder många år ackumulerats. Även om det nu känns som att vi har en god kontroll över den löpandeekonomin så måste vi på lång sikt hitta fler finansieringskällor till stationens verksamhet. Det är tillexempel mycket otillfredsställande att vi nu inte har någon heltidsanställd personal, något som på siktmåste lösas.Fågelstationens gamla dröm om att ha en egen filial söder om Sahara gick i uppfyllelse under 1999 meden månads försöksverksamhet i Nigeria under våren. Denna slog väl ut på alla sätt och verksamhetenskall nu intensifieras under 2000.Datahanteringen fick sig en rejäl skjuts framåt under året och kan vi bara snart förnya maskinparken finnsgrunden för en smidig och effektiv datahantering vid stationen. Detta kommer att underlätta bådeutåtriktad verksamhet (Internet) och eget analysarbete.Ottenby Försäljnings AB (OFAB), som drivit den affärsmässiga delen av stationens verksamhet sedan1995, fortsatte sin verksamhet parallellt med fågelstationens ideella verksamhet. Genom verksamheten iNaturum och restaurang Fågel Blå svarar OFAB för en viktig del av fågelstationens publika aktiviteter.Det är av stor vikt för framtiden att behålla och utveckla det goda samarbetet mellan fågelstationen ochOFAB.Figur 1. Åke LindströmFigur 2. Patrik Rhönnstad, platschef 1999Kontinuiteten i det praktiska arbetet på stationen blev naturligtvis något lidande av att den rutineradepersonalen försvunnit. Situationen hjälptes dock upp signifikant av att OFABs personal fanns på plats(Håkan och Annika Lundkvist, Gösta Friberg) samt att nye platschefen och många av de ideelltarbetande hade erfarenhet från tidigare år.
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| 7. |
- Andersson, G., et al.
(författare)
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Arthropod populations in a sub-arctic environment facing climate change over a half-century: variability but no general trend
- 2022
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Ingår i: Insect Conservation and Diversity. - : Wiley. - 1752-458X .- 1752-4598. ; 15:5, s. 534-542
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Tidskriftsartikel (refereegranskat)abstract
- Dramatic declines of some arthropod populations have recently received a lot of attention. Identified declines have mainly been attributed to changes in agriculture, climate, pathogen prevalence and light pollution, as well as cross-regional effects of, e.g., drifting pesticides. However, the overall picture is complex and debated, and there is a need for systematically collected long-term data, not least from areas relatively unaffected by humans. We monitored the abundance of arthropods (mainly insects) in subalpine birch forest in Swedish Lapland over a period of 53 years (1968-2020), in an area comparatively unaffected by human activities. Arthropod abundance was assessed by yearly systematic counts on 24,000 birch shoots, in the second half of June. Animals were categorised into 17 different groups directly upon counting, dependent on taxonomy and life stage (imago, larva). Overall, there was no significant change in arthropod numbers. Nor did estimates of the total biomass of arthropods (using group-specific indices of the mass of individuals) show any significant trend. Accordingly, there are no signs that the arthropod abundance or biomass on birch in this subarctic study site has gone through the same declines as have been reported from sites in other habitats. The reason may be that the impact of factors identified worldwide as drivers of arthropod declines so far are small or non-existent because of the low human population density in this area.
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| 8. |
- Andersson, K, et al.
(författare)
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Depletion of enterochromaffin-like cell histamine increases histidine decarboxylase and chromogranin A mRNA levels in rat stomach by a gastrin-independent mechanism.
- 1996
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Ingår i: Scandinavian Journal of Gastroenterology. - 1502-7708. ; 31:10, s. 65-959
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Gastrin activates histidine decarboxylase (HDC) and increases HDC and chromogranin A (CGA) mRNA levels in histamine-producing enterochromaffin-like (ECL) cells in the rat stomach. We have studied how histamine depletion by subcutaneous infusion of the HDC inhibitor alpha-fluoromethyl-histidine (alpha-FMH) affects how ECL cells respond to hypergastrinemia in terms of HDC and CGA mRNA levels. METHODS: In one experiment rats received alpha-FMH for 24 h. In another experiment rats received alpha-FMH, omeprazole (perorally), or a combination of the two drugs for 10 days. In a third experiment antrectomized rats were treated with alpha-FMH for 48 h. The circulating gastrin level, oxyntic mucosal histamine concentration, HDC activity, and HDC and CGA mRNA levels were determined. RESULTS: alpha-FMH for 24 h increased the HDC and CGA mRNA levels without increasing the serum gastrin concentration. alpha-FMH for 10 days increased the serum gastrin concentration twofold. alpha-FMH + omeprazole resulted in the same serum gastrin concentration as after omeprazole alone (eightfold increase). HDC mRNA levels were higher after alpha-FMH + omeprazole than after omeprazole alone. alpha-FMH alone induced an HDC mRNA level that was similar in magnitude to that observed after omeprazole, although the serum gastrin concentration after alpha-FMH was much lower. In antrectomized rats alpha-FMH increased the HDC and CGA mRNA levels without increasing the serum gastrin concentration. CONCLUSION: ECL-cell histamine depletion will increase mRNA levels for HDC and CGA by a gastrin-independent mechanism, possibly involving abolished histamine autofeedback inhibition.
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| 9. |
- Bakx, Tristan, et al.
(författare)
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Areas of high conservation value support specialist forest birds
- 2023
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Ingår i: Ecosphere. - 2150-8925. ; 14:6
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Tidskriftsartikel (refereegranskat)abstract
- Scientists have deemed existing protected areas in European forests insufficient to halt and reverse biodiversity loss resulting from ongoing intensification of management. In Sweden, protected areas are therefore complemented with the so-called areas of high conservation value (AHCVs), that is, landscapes encompassing both protected and assumed biodiversity-valuable areas as well as surrounding land, where managers should pay increased attention to biodiversity. However, it is not known whether AHCVs are chosen so that the species they are intended to benefit inhabit such AHCVs to a higher degree. We investigated whether the occurrence and abundance of bird species that may be particularly vulnerable to intense forest management were higher in Swedish forest landscapes proposed as AHCVs compared with other forest landscapes. To this end, we fitted a joint species distribution model to bird count data for 70 forest bird species from a standardized Swedish bird monitoring scheme. Twelve of the 20 forest specialists (60%) were detected to occur more often inside AHCVs than outside, whereas no forest specialist was less likely to occur inside AHCVs. For forest generalists, the corresponding figures were 28% and 18%, respectively. Six of 15 red-listed species (40%) were detectably more likely to occur inside AHCVs. The relationship between AHCV status of landscapes and the abundance of individual species was not as consistently negative or positive. The higher occurrence of specialists and threatened species inside AHCVs than outside of them suggests that if managed correctly, AHCVs are important habitat for a considerable part of the specialized forest avifauna in Sweden. We conclude that AHCVs represent an opportunity for designing green infrastructure benefitting Swedish forest biodiversity.
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| 10. |
- Bakx, Tristan R.M., et al.
(författare)
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Farmland birds occupying forest clear-cuts respond to both local and landscape features
- 2020
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Ingår i: Forest Ecology and Management. - : Elsevier BV. - 0378-1127. ; 478
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Tidskriftsartikel (refereegranskat)abstract
- Agricultural landscapes have changed fast in Europe, which has led to steep declines in farmland biodiversity. While this has differentially impacted “farmland species”, some of these seem to be able to use alternative man-made open habitats in forests, such as forest clear-cuts and powerline rights-of-way. We investigated the use of clear-cuts by two historically declining farmland birds, the Yellowhammer (Emberiza citrinella) and the Red-backed Shrike (Lanius collurio), to determine both local and landscape habitat characteristics of clear-cuts used for breeding. Among 101 clear-cuts visited in Scania, southern Sweden, 27% were occupied by Yellowhammers and 12% by Red-backed Shrikes. Yellowhammer occurrence in clear-cuts was positively related to local spruce cover (the planted tree species). There was also an interaction between clear-cut size and the proportion of farmland in the landscape, such that the positive effect of the proportion of farmland nearby was stronger for larger clear-cuts. Red-backed Shrike occurrence was positively related to clear-cut size and the local presence of piles of forest residues (tops and branches). The relation between occurrence and the proportion of clear-cuts in the landscape was positive for small clear-cuts and negative for larger ones. Yellowhammers and Red-backed shrikes are affected by both the local habitat structure in the clearcut and on the composition of the surrounding landscape, most likely because they use the clear-cut for nesting and the surroundings as complementary feeding habitat. To what extent clear-cuts as complementary breeding habitat to farmland may contribute to the conservation of Yellowhammers and Red-backed shrikes, as well as other farmland birds, is a promising path for future investigations.
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| 11. |
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| 12. |
- Bradter, Ute, et al.
(författare)
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Decomposing the spatial and temporal effects of climate on bird populations in northern European mountains
- 2022
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Ingår i: Global Change Biology. - : Wiley. - 1354-1013 .- 1365-2486. ; 28:21, s. 6209-6227
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Tidskriftsartikel (refereegranskat)abstract
- The relationships between species abundance or occurrence versus spatial variation in climate are commonly used in species distribution models to forecast future distributions. Under “space-for-time substitution”, the effects of climate variation on species are assumed to be equivalent in both space and time. Two unresolved issues of space-for-time substitution are the time period for species' responses and also the relative contributions of rapid- versus slow reactions in shaping spatial and temporal responses to climate change. To test the assumption of equivalence, we used a new approach of climate decomposition to separate variation in temperature and precipitation in Fennoscandia into spatial, temporal, and spatiotemporal components over a 23-year period (1996–2018). We compiled information on land cover, topography, and six components of climate for 1756 fixed route surveys, and we modeled annual counts of 39 bird species breeding in the mountains of Fennoscandia. Local abundance of breeding birds was associated with the spatial components of climate as expected, but the temporal and spatiotemporal climatic variation from the current and previous breeding seasons were also important. The directions of the effects of the three climate components differed within and among species, suggesting that species can respond both rapidly and slowly to climate variation and that the responses represent different ecological processes. Thus, the assumption of equivalent species' response to spatial and temporal variation in climate was seldom met in our study system. Consequently, for the majority of our species, space-for-time substitution may only be applicable once the slow species' responses to a changing climate have occurred, whereas forecasts for the near future need to accommodate the temporal components of climate variation. However, appropriate forecast horizons for space-for-time substitution are rarely considered and may be difficult to reliably identify. Accurately predicting change is challenging because multiple ecological processes affect species distributions at different temporal scales.
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| 13. |
- Brlík, Vojtěch, et al.
(författare)
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Long-term and large-scale multispecies dataset tracking population changes of common European breeding birds
- 2021
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Ingår i: Scientific Data. - : Springer Science and Business Media LLC. - 2052-4463. ; 8:1
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Tidskriftsartikel (refereegranskat)abstract
- Around fifteen thousand fieldworkers annually count breeding birds using standardized protocols in 28 European countries. The observations are collected by using country-specific and standardized protocols, validated, summarized and finally used for the production of continent-wide annual and long-term indices of population size changes of 170 species. Here, we present the database and provide a detailed summary of the methodology used for fieldwork and calculation of the relative population size change estimates. We also provide a brief overview of how the data are used in research, conservation and policy. We believe this unique database, based on decades of bird monitoring alongside the comprehensive summary of its methodology, will facilitate and encourage further use of the Pan-European Common Bird Monitoring Scheme results.
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| 14. |
- Chevalier, Mathieu, et al.
(författare)
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Changes in forest bird abundance, community structure and composition following a hurricane in Sweden
- 2019
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Ingår i: Ecography. - : Wiley. - 0906-7590 .- 1600-0587. ; 42:11, s. 1862-1873
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Tidskriftsartikel (refereegranskat)abstract
- The effect that extreme natural events have on biological diversity is relatively poorly known. We used a before–after control-impact (BACI) design to analyze changes in bird abundances and communities following Hurricane Gudrun, which struck southern Sweden in January 2005, felling 75 million m3 of forest and causing damage to 5% of forested areas (half a million hectares) in a few hours. We used recent measures of impact in combination with classical BACI contrasts to analyze bird count data from a monitoring program in Sweden. We investigated changes in the abundance of 17 species commonly found in forests, along with changes in species composition and functional structure of the bird community. In total, we considered 34 response variables and examined whether responses were immediate or long-term. There was no evidence of a strong effect of the hurricane on the abundances of six species. Estimates of the effects on five species were too uncertain to draw inferences. We detected positive and negative effects of the hurricane on the abundances of the remaining six species, but the magnitude of effects often was small. Generally, the effects were in the expected direction: negative on birds associated with mature forest and positive on birds associated with open land or young forest. We found evidence of an increase in the proportion of species that nest on the ground and a decrease in the proportion of species that nest in cavities and trees. In contrast, the hurricane had no discernible effect on functional measures of diversity (richness, evenness or divergence), or on communities’ reproductive or morphological characteristics. Our results suggest that the hurricane affected bird populations and communities, but the magnitude of effects was generally small.
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| 15. |
- Couet, Joséphine, et al.
(författare)
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Short-lived species move uphill faster under climate change
- 2022
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Ingår i: Oecologia. - : Springer Science and Business Media LLC. - 0029-8549 .- 1432-1939. ; 198:4, s. 877-888
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Tidskriftsartikel (refereegranskat)abstract
- Climate change is pushing species ranges and abundances towards the poles and mountain tops. Although many studies have documented local altitudinal shifts, knowledge of general patterns at a large spatial scale, such as a whole mountain range, is scarce. From a conservation perspective, studying altitudinal shifts in wildlife is relevant because mountain regions often represent biodiversity hotspots and are among the most vulnerable ecosystems. Here, we examine whether altitudinal shifts in birds’ abundances have occurred in the Scandinavian mountains over 13 years, and assess whether such shifts are related to species’ traits. Using abundance data, we show a clear pattern of uphill shift in the mean altitude of bird abundance across the Scandinavian mountains, with an average speed of 0.9 m per year. Out of 76 species, 7 shifted significantly their abundance uphill. Altitudinal shift was strongly related to species’ longevity: short-lived species showed more pronounced uphill shifts in abundance than long-lived species. The observed abundance shifts suggest that uphill shifts are not only driven by a small number of individuals at the range boundaries, but the overall bird abundances are on the move. Overall, the results underscore the wide-ranging impact of climate change and the potential vulnerability of species with slow life histories, as they appear less able to timely respond to rapidly changing climatic conditions.
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| 16. |
- Dahlén, Janne, et al.
(författare)
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Fåglar i Norrbottens län förekomst och populationsutveckling 1998-2007
- 2009
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- I denna rapport presenteras förekomst och sentida populationsutveckling hos Norrbottens fåglarunder perioden 1996-2007 (förekomst) eller 1998/2002-2007 (trender). Rapporten bygger pådata från Svensk Fågeltaxerings standardrutter, ett nationellt övervakningsprogram som drivsvid Ekologiska institutionen, Lunds universitet. Projektet ingår i Naturvårdsverkets miljöövervakningssystem.Totalt finns 716 standardrutter i Sverige, 168 av dessa ligger i Norrbottens länoch inventeras som en kombinerad linje- och punktaxering. I denna rapport har endast data frånlinjedelen av inventeringarna använts. Alla rutterna har inventerats minst en gång och i snittså har närmare 60 rutter inventerats årligen i länet sedan 2002, vilket var det år då man ser entydlig ökning i antalet inventerade rutter.Nationellt sett presenteras trender från 1998 och vi har valt att göra på samma sätt i Norrbottenslän för att lätt kunna göra jämförelser med de nationella trenderna. Det är dock många artersom inte observerats i tillräckligt stort antal för att presentera tillförlitliga trender från 1998 (tioår). Vi har därför valt att presentera trender också från 2002 (sex år). Det generella mönstret visarpå att det gått betydligt bättre för fåglarna om 1998 används som startår (genomsnittlig årligökning på 2,6 %) än om man använder 2002 som startår (genomsnittlig årlig minskning på 1,4%). I båda fallen ska man vara medveten om att det endast är korttidstrender och att man därmedska vara försiktig med tolkningen av dessa, särskilt med trenderna beräknade från 2002.Flera olika fågelindikatorer har räknats ut för att spegla den biologiska mångfalden. Varjeindikator visar den genomsnittliga trenden för en grupp arter, vi har använt indikatorerna frånorganisationen European Bird Census Council (EBCC) som nu används som officiella indikatorerinom EU och indikatorerna för de Svenska miljömålen. Indikatorerna från EU, som skaspegla hur det går för de vanliga fåglarna i jordbrukslandskapet och skogen samt övriga vanligafåglar, pekar alla svagt nedåt för Norrbottens län. Minskningarna är dock marginella och intestatistiskt säkerställda.De Svenska miljömålen har fågelindikatorer förEtt rikt odlingslandskap, Levande skogarochStorslagen fjällmiljö, för sistnämnda mål finns två indikatorer. Vanliga jordbruksfåglarvisar på en stabil trend och förLevande skogar är trenden svagt icke signifikant positiv. FörStorslagen fjällmiljövisar trenden för kalfjället på en mer eller mindre stabil situation med betydandevariation mellan åren och indikatorn för fjällbjörkskogen är negativ.Vi har även beräknat trender för rödlistade arter och för arter som tillhör EU:s fågeldirektiv.I båda fallen är det dock för få arter som inräknats med tillräckligt många individer per år för attkomma med i beräkningen för att vi ska rekommendera att dessa samlade trender ska användassom indikatorer för utvecklingen hos grupperna i sin helhet. Trenden för de rödlistade arterna iNorrbotten pekar icke signifikant nedåt, variationen mellan åren är stor. Orsaken till den negativatrenden förklaras till stor del av den kraftiga minskningen hos brushane. Trenden för arteringående i EU: fågeldirektiv i Norrbotten pekar på en svag icke signifikant nedgång med småvariationer mellan åren.För fåglar med olika flyttningsvanor gick det under perioden 2002-2007 bäst för stannfåglaroch kortdistansflyttare som ökade signifikant. Däremot minskade både medel- och långdistansflyttarei antal under samma period.Vadare är ytterligare en grupp som vi har valt att presentera en gemensam trend för, då de ären typisk grupp för de norrländska myrarna och fjällhedarna, figur 1. Trenden för artgruppen är2Figur 1.Ljungpipare, en karaktärsfågel på fjällens myrar och hedar i Norrbottens län.Vi presenterar utbredningskartor med mått på relativ fågeltäthet för alla arter som är observeradepå standardrutterna i Norrbottens län för att ge en geografisk bild över var respektiveart förekommer och i vilka tätheter. Vi presenterar även kartor som visar hur de totala relativatätheterna varierar över länet för alla arter sammantaget, för rödlistade arter och fågeldirektivsarterna.Dessa visar dock inte på några tydliga generella mönster. För artrikedomen finns dockett tydligt mönster som visar på en gradient med de artrikaste rutterna vid kusten och de artfattigastepå kalfjällen i väster. Individrikedomen ser ut att vara som högst i den fjällnära skogenoch på några ställen längs kusten.
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| 17. |
- Dahlström Wester, Maria, et al.
(författare)
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Accumulation of 10B in human synovial sarcoma cells in vitro for possible use in BNCT
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Synovial sarcoma is a distinct tumour with unique promise for targeted therapy. Due to the location and characteristics, boron neutron capture therapy (BNCT) might be an interesting alternative treatment regimen. The binary method utilizes the ionizing effects of high energy short-ranged fission particles produced after the capturing of neutrons by stable 10B. This study reports results regarding the accumulation of 10B administered as boronophenylalanine (BPA) in a human synovial sarcoma cell line (4SS) in vitro. 4SS cells were incubated in BPAcontaining cell culture medium and cell-associated boron was analysed using inductively coupled plasma atomic emission spectroscopy (ICP-AES). The results show that 4SS cells accumulate boron in a clinical relevant concentration range. Further investigations may state the potential of BNCT as a treatment modality for synovial sarcomas and explore the possibilities of a directed delivery of boron-containing substances to receptors specifically expressed in this malignancy.
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| 18. |
- Dahlström Wester, Maria, 1979-
(författare)
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Aspects of Tumour Targeting : Preclinical Studies on Human Malignant Cells in vitro
- 2009
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Exclusive eradication of tumour cells causing minimal damage to healthy tissue, a concept referred to as targeting, is an interesting approach to improve the outcome for patients afflicted with cancer.The general aim of this thesis was to highlighten aspects that could be of importance in developing novel treatment regimens based on specific targeting of tumour cells. Two variants of targeting strategies, boron neutron capture therapy (BNCT) and platelet-derived growth factor receptor (PDGFR) tumour targeting were studied in vitro.In BNCT, the ability of boron-10, 10B, to capture neutrons is utilized. The capture reaction initiate emission of high linear energy transfer (LET) particles which exerts potential damaging effects on exposed cells. A preferential accumulation of at least 10 μg 10B/g tumour tissue is suggested to be required for effective clinical outcome. Here, the accumulation of boronophenylalanine, BPA, was investigated in human glioma, synovial sarcoma, fibroblast and monocytoid cells in vitro. For the purpose of quick and effective separation of extracellular and cell-associated boron, a rapid cell filtration method was developed. Inductively coupled plasma atomic emission spectroscopy, ICP-AES, was used to analyse the amount of boron associated to the cells.Over-expression of PDGFRs may render the possibility to target certain tumours using PDGF-based conjugates for a specific delivery of cytotoxic agents. PDGF-AA was conjugated to dextran of two different sizes, 10 and 40 kDa, and compared with 125I-radiolabelled PDGF-AA regarding accumulation, retention and localisation in human glioma cells in vitro.A boron concentration of >10 μg 10B/g tumour tissue was found in all human cell lines studied. For the two glioma cell lines, the results extend differences between the two although originating from the same human tumour material. Since fibroblasts and monocytoid cells, here used to represent normal cells, accumulated boron at a clinically relevant amount one may have to consider the role of these cells in/at the tumour site during treatment. Regarding results for the human synovial sarcoma cells, further investigations may state the potential of BNCT as a treatment modality and explore the possibilities of a directed delivery of boron-containing substances to receptors specifically expressed in this malignancy.PDGF-AA-based dextran conjugates, preferentially 10 kDa dextran conjugates, showed in vitro properties that were superior to radiolabelled unconjugated PDGF-AA. A prolonged retention time was observed for the conjugates. Radiolabelled PDGF-AA was mainly determined to be located intracellular but the localisation, internalised or membrane-associated, of radiolabelled conjugates seemed to be dependent on the composition of the conjugate. It is of interest to explore the potential of dextran conjugates carrying toxic substances for therapeutic purpose.
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| 19. |
- Dahlström Wester, Maria, et al.
(författare)
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Targeting malignant glioma cells in vitro using platelet-derived growth factor AA-based conjugates
- 2009
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Ingår i: Journal of drug targeting. - : Informa UK Limited. - 1029-2330 .- 1061-186X. ; , s. 1-10
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Tidskriftsartikel (refereegranskat)abstract
- Glioblastoma multiforme (GBM) is an unusually aggressive brain tumor; it is also highly heterogeneous. Poor prognosis and a median survival of less than 1 year, using conventional treatment, calls for development of new treatment strategies. Overexpression and/or amplification of platelet-derived growth factor alpha receptors (PDGFalphaRs) in GBM might act as potential targets for a novel therapeutic approach. In this study, conjugates based on PDGFAA-ligand and dextran, of different sizes (10 and 40 kDa dextran), were prepared and investigated regarding targeting properties in vitro. Three human malignant glioma cell lines, U343MGa31L, U343MGaCl2:6, and U563MG, were used because of their previously reported differences in receptor expression and behavior. PDGFAA-based 10 kDa dextran iodine-125 radiolabeled conjugates showed the most favorable properties according to results achieved in accumulation, retention, and localization of cell-associated radioactivity. In comparison with dextran-(125)I-tyrosine delivered radioactivity, the PDGFAA-based dextran conjugates confirm the potential of receptor targeting.
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| 20. |
- Dalby, Lars, et al.
(författare)
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The status of the Nordic populations of the Mallard (Anas platyrhynchos) in a changing world
- 2013
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Ingår i: Ornis Fennica. - : Finnish Omithological Soc. - 0030-5685. ; 90:1, s. 2-15
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Tidskriftsartikel (refereegranskat)abstract
- Dabbling ducks (Anas spp.) are importantmigratory quarry species, protected as a shared resource under international legislation. However, there is a lack of sufficient high-quality data on vital demographic rates and long-term trends in numbers to judge the conservation status of many duck populations at the flyway level. In response to reported declines in the North-West European flyway population of theMallard, we compiled available data on this species in the Nordic countries up to 2010. Generally, national breeding numbers showed increasing trends, wintering abundance showed variable trends, and productivitymeasures indicated stable or increasing trends.Major knowledge gaps were identified, namely the size of hunting bags, the influence of the released Mallards and the role of short-stopping in explaining changing patterns of wintering abundance across the North-West European flyway. Numerically the Nordic breeding population appears in “good condition”, and the wintering numbers have been either stable or increasing in the last two decades. The annual number of releases needs to be determined in order to judge the sustainability of the current levels of exploitation. Overall, none of the indicators showed alarming signs for the Mallard population in the Nordic countries when considered in isolation. However, the widespread decline in wintering numbers elsewhere across North-western Europe requires urgent pan-European action.
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| 21. |
- Dalby, Lars, et al.
(författare)
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The status of the Nordic populations of the Mallard (Anas platyrhynchos) in a changing world
- 2013
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Ingår i: Ornis Fennica. - : University of Helsinki. - 0030-5685. ; 90:1, s. 2-15
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Tidskriftsartikel (refereegranskat)abstract
- Dabbling ducks (Anas spp.) are important migratory quarry species, protected as a shared resource under international legislation. However, there is a lack of sufficient high-quality data on vital demographic rates and long-term trends in numbers to judge the conservation status of many duck populations at the flyway level. In response to reported declines in the North-West European flyway population of the Mallard, we compiled available data on this species in the Nordic countries up to 2010. Generally, national breeding numbers showed increasing trends, wintering abundance showed variable trends, and productivity measures indicated stable or increasing trends. Major knowledge gaps were identified, namely the size of hunting bags, the influence of the released Mallards and the role of short-stopping in explaining changing patterns of wintering abundance across the North-West European flyway. Numerically the Nordic breeding population appears in "good condition", and the wintering numbers have been either stable or increasing in the last two decades. The annual number of releases needs to be determined in order to judge the sustainability of the current levels of exploitation. Overall, none of the indicators showed alarming signs for the Mallard population in the Nordic countries when considered in isolation. However, the widespread decline in wintering numbers elsewhere across North-western Europe requires urgent pan-European action.
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| 22. |
- Debayle, Edouard J.M., et al.
(författare)
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Great Snipes in sub-Saharan Africa : Seasonal patterns of abundance, moult and body mass in relation to age and sex
- 2017
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Ingår i: Wader Study. - : International Wader Study Group. - 2058-8410. ; 124:3, s. 186-196
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Tidskriftsartikel (refereegranskat)abstract
- Great Snipes Gallinago media spend about eight months per year in sub-Saharan Africa, but most aspects of their non-breeding ecology are poorly known. We analysed the seasonal pattern of appearance, flight feather moult (primaries and secondaries), and body mass in relation to age and sex, based on 3,247 birds collected by hunters in 1990–2000 in Benin, Gabon, Cameroon and the Democratic Republic of Congo. Adult males arrived in Africa from mid-August with a suspended flight feather moult. Adult females on average arrived somewhat later, and were about one month behind in the progress of flight feather moult. The adults of both sexes resumed moult immediately upon arrival. Flight feather moult was generally completed by the end of November in males, and end of December in females. Juvenile Great Snipes arrived later than adults and did not moult their flight feathers. The temporal pattern of occurrence at the different study sites suggests a general relocation of snipes from West Africa to Central Africa in October-December. Body masses did not differ between age groups and were generally low from August to February (155–170 g in males and 165–185 g in females). Males apparently departed northwards from late March to late April, and the females about two weeks later. Prior to departure, body mass increased on average with about 50 g (in both sexes), suggesting a departure fuel load of 31–33% above lean body mass. In periods of high and stable mass increase, fuel was deposited at rates of about 0.8–1.3 g/d (or 0.5–0.8% of lean body mass/d). The heaviest males and females had a total body mass of 242 and 250 g, respectively. This kind of traditional natural history data forms an important complement to the new type of data emerging from modern tracking techniques.
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| 23. |
- Devictor, Vincent, et al.
(författare)
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Differences in the climatic debts of birds and butterflies at a continental scale
- 2012
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Ingår i: Nature Climate Change. - 1758-6798. ; 2:2, s. 121-124
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Tidskriftsartikel (refereegranskat)abstract
- Climate changes have profound effects on the distribution of numerous plant and animal species(1-3). However, whether and how different taxonomic groups are able to track climate changes at large spatial scales is still unclear. Here, we measure and compare the climatic debt accumulated by bird and butterfly communities at a European scale over two decades (1990-2008). We quantified the yearly change in community composition in response to climate change for 9,490 bird and 2,130 butterfly communities distributed across Europe(4). We show that changes in community composition are rapid but different between birds and butterflies and equivalent to a 37 and 114 km northward shift in bird and butterfly communities, respectively. We further found that, during the same period, the northward shift in temperature in Europe was even faster, so that the climatic debts of birds and butterflies correspond to a 212 and 135 km lag behind climate. Our results indicate both that birds and butterflies do not keep up with temperature increase and the accumulation of different climatic debts for these groups at national and continental scales.
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| 24. |
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| 25. |
- Dänhardt, Juliana, et al.
(författare)
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Farmland as stopover habitat for migrating birds - effects of organic farming and landscape structure
- 2010
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Ingår i: Oikos. - : Wiley. - 1600-0706 .- 0030-1299. ; 119:7, s. 1114-1125
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Tidskriftsartikel (refereegranskat)abstract
- Agricultural intensification in Europe has affected farmland bird populations negatively, both during summer and winter. Although the migratory period poses separate challenges on birds than breeding and wintering, the consequences of farming practices for birds during migration remain poorly investigated. We monitored abundance and species richness of migratory birds in autumn at matched pairs of organic and conventional farms situated either in intensively farmed open plains (homogeneous landscapes) or in small-scale farming landscapes (heterogeneous landscapes) in southern Sweden. Total bird density did not differ between landscape types but was marginally higher on organic compared to conventional farms. When including taxonomic status in the model (passerines vs non-passerines), we found significantly more birds on organic farms, and more non-passerines in the homogeneous landscapes. The effect of farming practice and landscape type on density differed between functional groups. Omnivore density was higher in the homogeneous landscapes, and invertebrate feeders were marginally more abundant on organic farms. The effects of farming practice on the overall species richness and on the density of granivorous birds were landscape dependent. In the homogeneous landscapes, organic farms held a higher number of species and density of granivorous birds than conventional farms, but there was no such difference in the heterogeneous landscapes. Thus, organic farming can enhance abundance and species richness of farmland birds during migration, but the effect differs between landscape types and species. The effectiveness of organic farming was highest in the homogeneous landscape making it important to promote organic farming there. However, for some species during migration, increased heterogeneity in homogeneous landscapes may have negative effects. We propose that migratory bird diversity in homogeneous landscapes may be best preserved by keeping the landscape open, but that a reduced agricultural intensity, such as organic farming, should be encouraged.
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