Contemporary ocean warming and freshwater conditions are related to later sea age at maturity in Atlantic salmon spawning in Norwegian rivers

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Betingede avtaler

Dersom to parter innleder en forhandling og det er usikkerhet knyttet til forutsetningene for avtalen, har partene grovt sett tre valg. De kan binde seg, og løpe en risiko for at kontrakten ikke blir regningssvarende. De kan unnlate å binde seg, og håpe at kontraheringsmuligheten byr seg ved senere anledning. Eller de kan gjøre kontrakten betinget, slik at den kun gjelder dersom en eller flere avtalte begivenheter inntreffer. De betingede avtaler er emnet for denne avhandlingen. Betingede avtaler lar partene ta høyde for usikkerhet knyttet til forhold som finansiering, grunnforhold eller tillatelser fra offentlige myndigheter. Det lar partene utsette bindingsspørsmålet til det foreligger en reell styrebehandling, eller partene kan gjøre avtalen betinget av signatur – slik at de har forutsigbarhet i forhandlingsprosessen. Slike forbehold kan være i begge parters interesse, eller det kan være motivert av én av partenes interesse i å gardere seg. Som kontraktsmekanisme gir det muligheter, men er også en kime til konflikt. Ved kodifiseringen av betingelser i UNIDROIT 2010 het det i kommentaren simpelthen: «In commer-cial practice, disputes often arise relating to conditions». Utsagnet må sies å være dekkende også for norske forhold. Avhandlingens siktemål er på de tilfeller hvor en part hevder seg fri under henvisning til at avtalen er betinget. Dette omfatter ikke bare ansvarsfrihet overfor eventuelle erstatningsrettslige krav, men også frihet fra avtaleforholdet overhodet. Perspektivet fordrer en mer inngående analyse av hva betingelser er, de prosessuelle rammene der hvor partene har tatt forbehold samt en analyse av hvilke plikter partene kan sies å ha når de har gjort avtalen betinget

The gut bacterium Bacteroides thetaiotaomicron influences the virulence potential of the enterohemorrhagic Escherichia coli0103:H25

Enterohemorrhagic E. coli (EHEC) is associated with severe gastrointestinal disease. Upon entering the gastrointestinal tract, EHEC is exposed to a fluctuating environment and a myriad of other bacterial species. To establish an infection, EHEC strains have to modulate their gene expression according to the GI tract environment. In order to explore the interspecies interactions between EHEC and an human intestinal commensal, the global gene expression profile was determined of EHEC O103:H25 (EHEC NIPH-11060424) co-cultured with B. thetaiotaomicron (CCUG 10774) or grown in the presence of spent medium from B. thetaiotaomicron. Microarray analysis revealed that approximately 1% of the EHEC NIPH-11060424 genes were significantly up-regulated both in co-culture (30 genes) and in the presence of spent medium (44 genes), and that the affected genes differed between the two conditions. In co-culture, genes encoding structural components of the type three secretion system were among the most affected genes with an almost 4-fold up-regulation, while the most affected genes in spent medium were involved in chemotaxis and were more than 3-fold up-regulated. The operons for type three secretion system (TTSS) are located on the Locus of enterocyte effacement (LEE) pathogenicity island, and qPCR showed that genes of all five operons (LEE1-LEE5) were up-regulated. Moreover, an increased adherence to HeLa cells was observed in EHEC NIPH-11060424 exposed to B. thetaiotaomicron. Expression of stx2 genes, encoding the main virulence factor of EHEC, was down-regulated in both conditions (co-culture/spent medium). These results show that expression of EHEC genes involved in colonization and virulence is modulated in response to direct interspecies contact between cells, or to diffusible factors released from B. thetaiotaomicron. Such interspecies interactions could allow the pathogen to recognize its predilection site and modulate its behaviour accordingly, thus increasing the efficiency of colonization of the colon mucosa, facilitating its persistence and increasing its virulence potential