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- Mikkelsen, Tarjei S, et al.
(author)
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Genome of the marsupial Monodelphis domestica reveals innovation in non-coding sequences
- 2007
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In: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 447:7141, s. 167-177
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Journal article (peer-reviewed)abstract
- We report a high-quality draft of the genome sequence of the grey, short-tailed opossum (Monodelphis domestica). As the first metatherian ('marsupial') species to be sequenced, the opossum provides a unique perspective on the organization and evolution of mammalian genomes. Distinctive features of the opossum chromosomes provide support for recent theories about genome evolution and function, including a strong influence of biased gene conversion on nucleotide sequence composition, and a relationship between chromosomal characteristics and X chromosome inactivation. Comparison of opossum and eutherian genomes also reveals a sharp difference in evolutionary innovation between protein-coding and non-coding functional elements. True innovation in protein-coding genes seems to be relatively rare, with lineage-specific differences being largely due to diversification and rapid turnover in gene families involved in environmental interactions. In contrast, about 20% of eutherian conserved non-coding elements (CNEs) are recent inventions that postdate the divergence of Eutheria and Metatheria. A substantial proportion of these eutherian-specific CNEs arose from sequence inserted by transposable elements, pointing to transposons as a major creative force in the evolution of mammalian gene regulation.
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- Buitenhuis, Miranda, et al.
(author)
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Protein kinase B (c-akt) regulates hematopoietic lineage choice decisions during myelopoiesis
- 2008
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In: Blood. - : American Society of Hematology. - 1528-0020 .- 0006-4971. ; 111:1, s. 112-121
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Journal article (peer-reviewed)abstract
- Hematopoiesis is a highly regulated process resulting in the formation of all blood lineages. Aberrant regulation of phosphatidylinositol-3-kinase (PI3K) signaling has been observed in hematopoietic malignancies, suggesting that regulated PI3K signaling is critical for regulation of blood cell production. An ex vivo differentiation system was used to investigate the role of PI3K and its downstream effector, protein kinase B (PKB/c-akt) in myelopoiesis. PI3K activity was essential for hematopoietic progenitor survival. High PKB activity was found to promote neutrophil and monocyte development, while, conversely, reduction of PKB activity was required to induce optimal eosinophil differentiation. In addition, transplantation of beta2-microglobulin (-/-) NOD/SCID mice with CD34(+) cells ectopically expressing constitutively active PKB resulted in enhanced neutrophil and monocyte development, whereas ectopic expression of dominant-negative PKB induced eosinophil development in vivo. Inhibitory phosphorylation of C/EBPalpha on Thr222/226 was abrogated upon PKB activation in hematopoietic progenitors. Ectopic expression of a nonphosphorylatable C/EBPalpha mutant inhibited eosinophil differentiation ex vivo, whereas neutrophil development was induced, demonstrating the importance of PKB-mediated C/EBPalpha phosphorylation in regulation of granulopoiesis. These results identify an important novel role for PKB in regulation of cell fate choices during hematopoietic lineage commitment.
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- Bäckstrand, Gunnar, et al.
(author)
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Ergonomics analysis in a virtual environment
- 2007
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In: International Journal of Manufacturing Research. - : InderScience Publishers. - 1750-0591. ; 2:2, s. 198-208
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Journal article (peer-reviewed)abstract
- Simulation can support the design of an ergonomic workplace by enabling early assessment of ergonomic conditions in a virtual environment. An important feature is the possibility to study alternative solutions or the effect of improvements from an ergonomics perspective. To be able to conduct an efficient and reliable evaluation in a virtual environment, an objective analysis method is essential. Such an analysis method should be integrated in the simulation software, and support a company's everyday ergonomics work process. In order to gain from existing ergonomics knowledge within a company, the possibility to implement such wisdom in the current simulation software becomes important. This paper presents an implementation work done with the purpose of integrating an established ergonomics work process into a virtual environment. It describes the benefits of an ergonomics work process where simulation and evaluation at early stages of a design process are key factors. The paper will also describe the integration process, i.e., the technical issues as well as the change in work methods.
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- Jiao, Liping, et al.
(author)
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Persistent toxic substances in remote lake and coastal sediments from Svalbard, Norwegian Arctic : Levels, sources and fluxes
- 2009
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In: Environmental Pollution. - : Elsevier. - 0269-7491 .- 1873-6424. ; 157:4, s. 1342-1351
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Journal article (peer-reviewed)abstract
- Surface sediments from remote lakes and coastal areas from Ny-Ålesund, Svalbard, Norwegian Arctic were analyzed for polycyclic aromatic hydrocarbons (PAHs), polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs). Relatively high levels of PAHs were encountered from several lakes from Ny-Ålesund, which were within the range of levels reported for European high mountain lakes and some urban/industrialized areas in the world, pointing to the role of remote Arctic lakes as potential reservoir of semi-volatile organic compounds. Specific patterns of PBDEs were observed, showing higher concentrations of lower brominated compounds such as BDE-7, 17 and 28. Estimated surface sediment fluxes of PAHs in Ny-Ålesund remote lakes were similar to those observed for some European high mountain lakes. The current PAH levels in sediments from three lakes exceeded Canadian sediment quality guidelines, suggesting the presence of possible risks for aquatic organisms and the need for further studies.
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- McAuliffe, Carmel, et al.
(author)
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Problem-solving ability and repetition of deliberate self-harm : a multicentre study.
- 2006
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In: Psychological Medicine. - : Cambridge University Press. - 0033-2917 .- 1469-8978. ; 36:1, s. 45-55
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Journal article (peer-reviewed)abstract
- Background. While recent studies have found problem-solving impairments in individuals who engage in deliberate self-harm (DSH), few studies have examined repeaters and non-repeaters separately. The aim of the present study was to investigate whether specific types of problem-solving are associated with repeated DSH. Method. As part of the WHO/EURO Multicentre Study on Suicidal Behaviour, 836 medically treated DSH patients (59% repeaters) from 12 European regions were interviewed using the European Parasuicide Study Interview Schedule (EPSIS II) approximately 1 year after their index episode. The Utrecht Coping List (UCL) assessed habitual responses to problems. Results. Factor analysis identified five dimensions – Active Handling, Passive-Avoidance, Problem Sharing, Palliative Reactions and Negative Expression. Passive-Avoidance – characterized by a pre-occupation with problems, feeling unable to do anything, worrying about the past and taking a gloomy view of the situation, a greater likelihood of giving in so as to avoid difficult situations, the tendency to resign oneself to the situation, and to try to avoid problems – was the problem-solving dimension most strongly associated with repetition, although this association was attenuated by self-esteem. Conclusions. The outcomes of the study indicate that treatments for DSH patients with repeated episodes should include problem-solving interventions. The observed passivity and avoidance of problems (coupled with low self-esteem) associated with repetition suggests that intensive therapeutic input and follow-up are required for those with repeated DSH.
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- Ren, Hongzu, et al.
(author)
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Evidence for the involvement of xenobiotic-responsive nuclear receptors in transcriptional effects upon perfluoroalkyl acid exposure in diverse species
- 2009
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In: Reproductive Toxicology. - : Elsevier. - 0890-6238 .- 1873-1708. ; 27:3-4, s. 266-277
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Journal article (peer-reviewed)abstract
- Humans and ecological species have been found to have detectable body burdens of a number of perfluorinated alkyl acids (PFAA) including perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS). In mouse and rat liver these compounds elicit transcriptional and phenotypic effects similar to peroxisome proliferator chemicals (PPC) that work through the nuclear receptor peroxisome proliferator-activated receptor alpha (PPARα). Recent studies indicate that along with PPARα other nuclear receptors are required for transcriptional changes in the mouse liver after PFOA exposure including the constitutive activated receptor (CAR) and pregnane X receptor (PXR) that regulate xenobiotic metabolizing enzymes (XME). To determine the potential role of CAR/PXR in mediating effects of PFAAs in rat liver, we performed a meta-analysis of transcript profiles from published studies in which rats were exposed to PFOA or PFOS. We compared the profiles to those produced by exposure to prototypical activators of CAR, (phenobarbital (PB)), PXR (pregnenolone 16 alpha-carbonitrile (PCN)), or PPARα (WY-14,643 (WY)). As expected, PFOA and PFOS elicited transcript profile signatures that included many known PPARα target genes. Numerous XME genes were also altered by PFOA and PFOS but not WY. These genes exhibited expression changes shared with PB or PCN. Reexamination of the transcript profiles from the livers of chicken or fish exposed to PFAAs indicated that PPARα, CAR, and PXR orthologs were not activated. Our results indicate that PFAAs under these experimental conditions activate PPARα, CAR, and PXR in rats but not chicken and fish. Lastly, we discuss evidence that human populations with greater CAR expression have lower body burdens of PFAAs.
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9. |
- Wei, S., et al.
(author)
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Historical trends of organic pollutants in sediment cores from Hong Kong
- 2008
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In: Marine Pollution Bulletin. - : Elsevier. - 0025-326X .- 1879-3363. ; 57:6-12, s. 758-766
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Journal article (peer-reviewed)abstract
- Recent studies have indicated the occurrence of a wide range of trace organic contaminants, including polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) in the Hong Kong environment. These contaminants are potentially harmful to ecological systems, particularly in coastal areas. In this study, two sediment cores (4 m) were collected from southern waters of Hong Kong in 2004 to study the historical trends, distribution patterns, and potential sources of trace organic contaminants. DDTs (p,p′-DDT, o,p′-DDT, p,p′-DDD, o,p′-DDD and p,p′-DDE), hexachlorohexanes (HCHs) (α and γ), hexachlorobenzene (HCB), and PCBs were detected in the samples, whereas other target compounds were all below detection limits. Many OCPs have not been produced or used for many years due to toxicological or environmental concerns and PCB use is prohibited in Hong Kong. However, some compounds were still detectable in recent years, and were found to be widely distributed in the environment, likely because of pollutant inputs from the highly industrialized Pearl River Delta region. These results provide important information on current and historical contamination in Hong Kong, and help to reconstruct the pollution history of these trace organic pollutants in Hong Kong coastal waters.
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