Oljeprisens påvirkning på Oslo Børs : har oljeprisen historisk sett vært en ledende indikator på det norske aksjemarkedet?

I denne utredningen er det gjort empiriske undersøkelser for å gjøre rede for sammenhengen mellom oljepris og det norske aksjemarkedet. Hovedfunnet er at oljeprisen er en ledende indikator på Oslo Børs. Perioden 1986 - januar 2009 er benyttet som grunnlag for hovedindeksen. Det er utført regresjoner med daglige og månedlige avkastninger for alle indekser. Analysen er i tillegg gjennomført med indekser i norske kroner og amerikanske dollar, og både WTI og Brent er benyttet som uavhengig variabel. Alle empiriske analyser er også gjennomført når tilbudssjokk i oljemarkedet utelates fra tallmaterialet

A general strategy for discovery of inhibitors and activators of RING and U-box E3 ligases with ubiquitin variants

RING and U-box E3 ubiquitin ligases regulate diverse eukaryotic processes and have been implicated in numerous diseases, but targeting these enzymes remains a major challenge. We report the development of three ubiquitin variants (UbVs), each binding selectively to the RING or U-box domain of a distinct E3 ligase: monomeric UBE4B, phosphorylated active CBL, or dimeric XIAP. Structural and biochemical analyses revealed that UbVs specifically inhibited the activity of UBE4B or phosphorylated CBL by blocking the E2∼Ub binding site. Surprisingly, the UbV selective for dimeric XIAP formed a dimer to stimulate E3 activity by stabilizing the closed E2∼Ub conformation. We further verified the inhibitory and stimulatory functions of UbVs in cells. Our work provides a general strategy to inhibit or activate RING/U-box E3 ligases and provides a resource for the research community to modulate these enzymes

Identification and characterization of mutations in ubiquitin required for non-covalent dimer formation

Ubiquitin (Ub) is a small protein that post-translationally modifies a variety of substrates in eukaryotic cells to modulate substrate function. The ability of Ub to interact with numerous protein domains makes Ub an attractive scaffold for engineering ubiquitin variants (UbVs) with high target specificity. Previously, we identified a UbV that formed a non-covalent stable dimer via a β-strand exchange, and in the current work we identified and characterized the minimal substitutions in the primary sequence of Ub required to form a higher ordered complex. Using solution angle scattering and X-ray crystallography, we show that a single substitution of residue Gly10 to either Ala or Val is sufficient to convert Ub from a monomer to a dimer. We also investigate contributions to dimer formation by the residues in the surrounding sequence. These results can be used to develop next-generation phage-display libraries of UbVs to engineer new interfaces for protein recognition

The Role of Marketing Logics in the Selection of Innovations

The presented study utilizes data collected from an extensive real world concept selection process in new product development (NPD), to investigate whether department specific dominant logics and competences influence the selections made by a marketing department, and what might be driving this logic. The study specifically investigates the impact of the departmental viewpoint onto idea selection in the innovation process, by comparing the selections made by the marketing department (n=31) with those of R&D (n=25) and company executives (n=8). In the NPD project seven concepts were screened for continuation through an individual pairwise comparison, to test eight hypotheses all based on h0: There is no difference between the innovations selected by marketing, R&D, and executive groups. Through an analysis of the between-department variance h0 was rejected (F(12, 366)= 2.312, p<.001), and the results from the eight following hypotheses lend support to extending the concept of dominant logics to the department level, providing some explanations for the large variance found in the evaluation of the three groups. The reported findings have important managerial implications, as they point to which type of logic, and thereby screening of ideas, can be achieved based on which departments are involved in the critical selection of ideas and concepts for continuation in NPD

Why do organochlorine differences between Arctic Regions vary among trophic levels?

Statistical analysis of organochlorine contaminants (OCs) in marine mammals has shown that, for most OCs, the European Arctic is more contaminated than the Canadian and U.S. Arctic. Recently, comparison of OC concentration ranges in seabirds, arctic cod (Boregadus saida), and zooplankton, found no difference between these regions. To address these inconsistencies, marine food web OC data from the European (central Barents Sea (CBS)) and Canadian Arctic (Northwater Polynya (NOW)) were simultaneously statistically analyzed. In general, concentrations of OCs were greater in seabirds and ringed seals (Phoca hispida) from the CBS as compared to the NOW; consistent with circumpolar trends observed in marine mammals. In contrast, levels of OCs were generally similar in zooplankton and arctic cod between the CBS and NOW. The main exception is HCH which had greater levels in the NOW across all trophic levels because of the greater proximity to sources in eastern Asia. The lack of differences in OC concentrations in zooplankton and Arctic cod from the European and Canadian Arctic suggest that regional differences in OC contamination in the Arctic have evened out. Reduced regional differences were not observed in marine mammals or seabirds because they are long-lived and also acquire contaminants from maternal transfer and hence reflect levels from the past when the European Arctic was more contaminated than the Canadian Arctic. In addition, seabirds may reflect exposure from other areas. This study highlights the potential problem of comparing spatial trends by using means and confidence intervals as compared to simultaneous statistical analysis of raw data. Differences in the spatial trends of OCs between trophic levels in the Arctic are important for consideration when assessing regional differences in spatial and temporal trends of discontinued and current-use contaminants. © 2005 American Chemical Society

Structure of UBE2K-Ub/E3/polyUb reveals mechanisms of K48-linked Ub chain extension

Ubiquitin (Ub) chain types govern distinct biological processes. K48-linked polyUb chains target substrates for proteasomal degradation, but the mechanism of Ub chain synthesis remains elusive due to the transient nature of Ub-handover. Here, we present the structure of a chemically trapped complex of E2 UBE2K covalently linked to donor Ub and acceptor K48-linked di-Ub, primed for K48-linked Ub chain synthesis by a RING E3. The structure reveals the basis for acceptor Ub recognition by UBE2K active site residues and the C-terminal Ub-associated (UBA) domain to impart K48-linked Ub specificity and catalysis. Furthermore, the structure unveils multiple Ub binding surfaces on the UBA domain that allow distinct binding modes for K48-linked and K63-linked Ub chains. This multivalent Ub binding feature serves to recruit UBE2K to ubiquitinated substrates to overcome weak acceptor Ub affinity and thereby promote chain elongation. These findings elucidate the mechanism of processive K48-linked polyUb chain formation by UBE2K

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No Abstract.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/50314/1/410190427_ftp.pd