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| 2. |
- Christensen, Torben, et al.
(författare)
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Factors controlling large scale variations in methane emissions from wetlands
- 2003
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Ingår i: Geophysical Research Letters. - 0094-8276 .- 1944-8007. ; 30:7
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Tidskriftsartikel (refereegranskat)abstract
- [1] Global wetlands are, at estimate ranging 115-237 Tg CH4/yr, the largest single atmospheric source of the greenhouse gas methane (CH4). We present a dataset on CH4 flux rates totaling 12 measurement years at sites from Greenland, Iceland, Scandinavia and Siberia. We find that temperature and microbial substrate availability (expressed as the organic acid concentration in peat water) combined explain almost 100% of the variations in mean annual CH4 emissions. The temperature sensitivity of the CH4 emissions shown suggests a feedback mechanism on climate change that could validate incorporation in further developments of global circulation models.
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| 8. |
- Ekberg, Lena, et al.
(författare)
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Meningen med semantiken
- 2003
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Ingår i: Grammatik i fokus : festskrift till Christer Platzack den 18 november 2003 = Grammar in focus : festschrift for Christer Platzack 18 November 2003. Vol. 1. - 9163145707
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
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| 10. |
- Larsson, Lena C, et al.
(författare)
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Induction of operational tolerance to discordant dopaminergic porcine xenografts.
- 2003
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Ingår i: Transplantation. - 1534-6080 .- 0041-1337. ; 75:9, s. 1448-1454
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Porcine embryonic neural tissue transplanted intracerebrally could potentially relieve the symptoms of Parkinson's disease if the immune response toward the graft could be overcome. However, conventional immunosuppressive treatments have proven inefficient in preventing rejection. An alternative is blocking the costimulatory signals for lymphocyte activation. Treatment with cytotoxic T-lymphocyte antigen 4 immunoglobulin (CTLA4Ig) and anti-CD40L has been successful in preventing rejection of xenografts in some experimental studies, but not all. Lymphocyte function antigen (LFA)-1 is an important costimulatory molecule for CD8+ T cells, and we hypothesize that blockade with anti-LFA-1 may enhance the efficacy of CTLA4Ig and anti-CD40L therapy. METHODS: C57BL/6 mice received intracerebral transplants of ventral mesencephalic tissue from embryonic porcine donors. CTLA4Ig, anti-CD40L, and anti-LFA-1 were administered every other day on days 0 to 8, and the transplants were studied after 4 to 6 weeks. Grafts were histologically analyzed for size, survival of dopaminergic nerve cells, and immune responses. Recipients were challenged with cultured glia cells of donor origin or an allogeneic skin graft to evaluate tolerance induction. RESULTS: Mice treated with all three substances had large grafts containing high amounts of dopamine cells but a low degree of immune response. Grafts in recipients challenged with glial cells showed an increased immunologic activity but were not rejected. Triple-treated mice showed a normal rejection process of the allogeneic skin grafts. CONCLUSION: After a short course of costimulation blocking therapy, discordant neural xenografts demonstrate long-term survival, withstand immunologic challenge, yet maintain host-versus-graft reactivity. Anti-LFA-1 complements CTLA4Ig and anti-CD40L in the induction of operational tolerance to these xenografts.
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| 11. |
- Larsson, Lena Cecilia, et al.
(författare)
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Simultaneous inhibition of B7 and LFA-1 signaling prevents rejection of discordant neural xenografts in mice lacking CD40L.
- 2002
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Ingår i: Xenotransplantation. - : Wiley. - 0908-665X. ; 9:1, s. 68-76
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Tidskriftsartikel (refereegranskat)abstract
- Transplantation of embryonic human neural tissue can restore dopamine neurotransmission and improve neurological function in patients with Parkinson's disease. Logistical and ethical factors limit the availability of human embryonic allogeneic tissue. Embryonic xenogeneic neural tissue from porcine donors is an alternative form of donor tissue, but effective immunomodulatory techniques are warranted for neural xenotransplantation to become clinically feasible. We transplanted embryonic porcine ventral mesencephalic tissue into the brains of adult untreated C57BL/6 mice, untreated CD40L-/-mice and CD40L-/-mice that received injections of anti-LFA-1, CTLA41g or both compounds. Double-treated CD40L-/-mice had large grafts with high numbers of dopaminergic neurons 4 wk after transplantation. The grafts were completely devoid of lymphocytes, macrophages and activated microglia. Untreated C57BL/6 mice had rejected their grafts. Untreated CD40L-/-mice and CD40L-/-mice treated with monotherapy of anti-LFA-1 or CTLA41g had smaller grafts and more microglial and lymphocytic infiltration than double-treated CD40L-/-mice. We conclude that immunomodulation with concomitant inhibition of LFA-1 and B7 signaling in the perioperative period in CD40L-/-mice prevented the rejection of discordant neural xenografts. The treatment most likely reduced antigen presenting capacity and interfered with the costimulatory signaling needed for T cell activation to occur.
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| 13. |
- Strindlund, Lena, 1973-, et al.
(författare)
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Långtidssjukskrivna inom Landstinget i Östergötland 2002 : Diagnoser, arbetsförhållanden och rehabiliteringsbehov
- 2004
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Studien ingår som en del i projektet ”Arbetsplatsen, arbetsledaren och den sjukskrivne - förutsättningar för samverkan med FK i arbetslivsinriktad rehabilitering”. Projektet är en del i samverkansavtalet mellan försäkringskassan och landstinget i Östergötland och syftar på sikt till att identifiera hinder och goda lösningar för framgångsrik rehabilitering tillbaka till arbete av sjukskrivna inom landstinget. Studien bygger på det enkätmaterial som landstinget skickade till samtliga 392 långtidssjukskrivna (>6 månader) medarbetare hösten 2002. Totalt 79% besvarade enkäten. En dryg tredjedel var sjukskrivna på grund av en kombination av psykiska och somatiska besvär, en fjärdedel på grund av psykiska besvär enbart och en femtedel på grund av besvär i rörelseorganen enbart. Andelen med psykiska besvär var högst bland yrkesgrupper med hög kvalifikationsnivå, medan besvär i rörelseorganen var vanligare i gruppen med låg kvalifikationsnivå. Mer än hälften hade varit sjukskrivna i mer än 1.5 år. Den självskattade hälsan, mätt med SF-36, var mycket låg bland de långtidssjuka, i detta avseende fanns inga större skillnader mellan hög- och lågkvalificerade grupper. Två tredjedelar av de långtidssjuka anger att arbetet helt eller delvis är orsaken till sjukskrivningen, i gruppen med psykiska besvär uppger 90% att arbetet är orsaken. Analys av svaren i en öppen fråga om vilka förhållanden i arbetet som bidragit till sjukskrivningen angavs en hög arbetsbelastning som hänför sig till bemanningsproblematik och små möjligheter till återhämtning som viktiga orsaksfaktorer. Många av de långtidssjuka uppger brister i ledarskapet som en starkt bidragande faktor till ohälsa. Brister i organisation av arbetet skapar oklarheter, som i sin tur leder till stress och hög arbetsbelastning. Mindre än hälften av de långtidssjuka uppger att arbetsledningen genomfört några åtgärder för att främja återgång i arbete. Inte heller försäkringskassan upplevs ha arbetat målinriktat för att främja arbetsåtergång, endast en tredjedel har fått en rehabiliteringsplan. För gruppen med psykiska besvär är framför allt minskad stress, ändrade arbetsuppgifter och kortare arbetstid viktiga förutsättningar för återgång i arbete. Gruppen med besvär i rörelseorganen anger att mindre kroppsligt tungt arbete, förändrade arbetsuppgifter och kortare arbetstid är betydelsefullt. Cirka 40% av de långtidssjukskrivna uppger att de skulle kunna arbeta på hel- eller deltid. Undersökningsgruppen var sjukskrivna då de besvarade enkäten. Detta kan innebära att man har en ökad benägenhet att tillskriva arbetsplatsen större orsak till ohälsan, än om man varit i arbete. De långtidssjukas upplevelse av arbetsledning och organisation och av hur de fått hjälp och stöd från olika aktörer har emellertid betydelse för hur man ser på sina möjligheter till återgång i arbete. Upplevelser av bristande engagemang och stöd under sjukskrivnings- och rehabiliteringsprocessen kan öka hindren för återgång i arbete. Kommentarerna i enkäten gav en bild av vilka förhållanden som är viktiga att utveckla för att etablera en rehabiliteringsprocess som möjliggör för de långtidssjuka att återgå i arbete. Till dessa förhållanden hör: Respekt för ohälsan Arbetsledningens förhållningssätt och agerande Rutiner på arbetsplatsen vid sjukskrivning och rehabilitering Vidgade möjligheter till arbetsträning och omplacering Bättre samverkan mellan rehabiliteringsaktörerna Sociala mötesplatser för långtidssjukskrivna
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| 14. |
- Strzelecka, Elzbieta, 1961-
(författare)
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Svenska partikelverb med in, ut, upp och ner : En semantisk studie ur kognitivt perspektiv
- 2003
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In this dissertation, the meanings of the Swedish particles in ‘in’, ut ‘out’, upp ‘up’ and ner ‘down’ are analysed when these words function as verbal particles and thereby, together with the verb, build phrasal verbs. The analysis, primarily based on cognitive semantics, includes semantically regular as well as lexicalised phrasal verbs, and seeks to explain the polysemy of the particles. The material consists of 884 different phrasal verbs, represented by 5,197 instances. The verbal particles are analysed in different contexts, including the domain of physical space as well as other domains. The starting point of the analysis is, in each case, the prototypical (spatial) meaning of the particle. The investigation shows that the varied, often disparate meanings of the verbal particles are motivated by image schemas and their transformations, and by metonymy and metaphorical usage. The meanings of the particles are linked to each other through family resemblance and make up a network. The verbal particles upp and in generally designate direction towards the centre and often have positive connotations, whereas the verbal particles ut and ner denote movement towards the periphery and have rather negative connotations. Vertical orientation appears to dominate the structuring of the domain of physical space in Swedish. For example, a movement in relation to a vertically orientated container (a container without a roof) is described using the vertical particles upp/ner and not the container particles in/ut. In a few special contexts, the particles examined indicate the speaker’s perspective.
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| 15. |
- Ström, Lena, et al.
(författare)
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The effect of vascular plants on carbon turnover and methane emissions from a tundra wetland
- 2003
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Ingår i: Global Change Biology. - : Wiley. - 1354-1013. ; 9:8, s. 1185-1192
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Tidskriftsartikel (refereegranskat)abstract
- This paper investigates how vascular plants affect carbon flow and the formation and emission of the greenhouse gas methane (CH4 ) in an arctic wet tundra ecosystem in NE Greenland. We present a field experiment where we studied, in particular, how species-specific root exudation patterns affect the availability of acetate, a hypothesized precursor of CH4 formation. We found significantly higher acetate formation rates in the root vicinity of Eriophorum scheuchzeri compared with another dominating sedge in the wetland, i.e. Dupontia psilosantha . Furthermore a shading treatment, which reduced net photosynthesis, resulted in significantly decreased formation rates of acetate. We also found that the potential CH4 production of the peat profile was highly positively correlated to the concentration of acetate at the respective depths, whereas it was negatively correlated to the concentration of total dissolved organic carbon. This suggests that acetate is a substrate of importance to the methanogens in the studied ecosystem and that acetate concentration in this case can serve as a predictor of substrate quality. To further investigate the importance of acetate as a predecessor to CH4 , we brought an intact peat-plant monolith system collected at the field site in NE Greenland to the laboratory, sealed it hermetically and studied the decomposition of (14) C-labelled acetate injected at the depth of methanogenic activity. After 4 h, (14) CH4 emission from the monolith could be observed. In conclusion, allocation of recently fixed carbon to the roots of certain species of vascular plants affects substrate quality and influence CH4 formation.
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| 18. |
- Vogel, Anna, 1969-
(författare)
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Swedish Dimensional Adjectives
- 2004
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The purpose of this study is to give a thorough and detailed account and analysis of the semantics of twelve Swedish dimensional adjectives: hög ’high/tall’, låg ’low’, bred ’broad/wide’, smal ’narrow’ vid ’broad’, trång ’narrow’, tjock ’thick’, tunn ’thin’, djup ’deep’, grund ’narrow’, lång ’long’ and kort ’short’. Focus has been placed on their spatial, non-metaphorical sense. The study was written within the framework of cognitive linguistics, where lexical definitions may be given in terms of prototypical and peripheral uses. Four sources of data have been considered: a corpus, consisting of contemporary fiction, an elicitation test, designed for the purpose, dictionary articles on the pertinent adjectives, and the author's own linguistic intuition as a native speaker. The methodology has involved categorisation of combinations of adjective and noun, based upon three major themes: orientation, function, and shape. In order to determine prototypical uses, precedence has been given to the outcome of the elicitation test over the corpus search. For both sources, frequency has played an important part. The ranking of senses as stated in the dictionary articles has also been considered.The results indicate that the dimensional adjectives differ quite markedly from each other, as opposed to a structural view where the adjectives traditionally have been regarded as forming a neat patchwork. Adjectives overlap each other for some uses (högt gräs ’high grass’, långt gräs ’long grass’ and even djupt gräs ’deep grass’), while there are also situations in which no dimensional adjective can describe an object. Furthermore, adjectives forming pairs, such as djup – grund ’deep – shallow’, do not exhibit full antonymy, despite the fact that dimensional adjectives are traditionally cited as examples par excellence concerning antonymy.
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| 19. |
- Walder, Renate, 1958-
(författare)
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Fokus på föra : Om svenska funktionsverbsfrasers semantik och valens, med särskild utgångspunkt i verbet föra
- 2004
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Functional verb structures, e.g. to have a break, to take into account, consist of a functional verb and an abstract noun (in a nominal phrase, NP, or a prepositional phrase, PP). The purpose of this thesis is to test whether three of the most central claims about these structures apply to Swedish functional verb structures with the verb föra. According to the first claim, the functional verb has lost most of its “original” meaning. In order to test this claim, a semantic analysis of the verb föra is presented. The analysis is based on the network model of meaning. It is suggested that the functional verb doesn’t “lose” meaning, but rather that meaning is partially suppressed as a result of restrictions governing domain-mapping within a metaphor. According to the second claim, nouns in functional verb structures do not take attributes. It is to be expected that this claim will be proven wrong because nouns in functional verb structures are predicates that have arguments and these appear as attributes on the syntactic level. In order to test the second claim, a corpus of functional verb structures with the verb föra has been collected. The valency of all the nouns in the functional verb structures within the corpus has been analysed. The analysis shows that most of these nouns have arguments that appear as attributes.The third claim states that the noun in a functional verb structure cannot change from singular to plural or from indefinite to definite form. This claim seems to apply only to functional verb structures with PP. It is suggested that the reason why functional verb structures with NP and PP differ in this respect lies in the way these different structures express aktionsart. The only way for a functional verb structure with NP to change aktionsart from unbounded to bounded is by changing the form of the NP. Functional verb structures with PP always express bounded aktionsart. The form of the PP has no impact on the aktionsart of the structure, there is therefore no need for the PP to change its form.
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