| 1. |
- Clark, Andrew G., et al.
(författare)
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Evolution of genes and genomes on the Drosophila phylogeny
- 2007
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 450:7167, s. 203-218
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Tidskriftsartikel (refereegranskat)abstract
- Comparative analysis of multiple genomes in a phylogenetic framework dramatically improves the precision and sensitivity of evolutionary inference, producing more robust results than single-genome analyses can provide. The genomes of 12 Drosophila species, ten of which are presented here for the first time (sechellia, simulans, yakuba, erecta, ananassae, persimilis, willistoni, mojavensis, virilis and grimshawi), illustrate how rates and patterns of sequence divergence across taxa can illuminate evolutionary processes on a genomic scale. These genome sequences augment the formidable genetic tools that have made Drosophila melanogaster a pre-eminent model for animal genetics, and will further catalyse fundamental research on mechanisms of development, cell biology, genetics, disease, neurobiology, behaviour, physiology and evolution. Despite remarkable similarities among these Drosophila species, we identified many putatively non-neutral changes in protein-coding genes, non-coding RNA genes, and cis-regulatory regions. These may prove to underlie differences in the ecology and behaviour of these diverse species.
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| 2. |
- Sodergren, Erica, et al.
(författare)
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The genome of the sea urchin Strongylocentrotus purpuratus.
- 2006
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 1095-9203 .- 0036-8075. ; 314:5801, s. 941-52
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Tidskriftsartikel (refereegranskat)abstract
- We report the sequence and analysis of the 814-megabase genome of the sea urchin Strongylocentrotus purpuratus, a model for developmental and systems biology. The sequencing strategy combined whole-genome shotgun and bacterial artificial chromosome (BAC) sequences. This use of BAC clones, aided by a pooling strategy, overcame difficulties associated with high heterozygosity of the genome. The genome encodes about 23,300 genes, including many previously thought to be vertebrate innovations or known only outside the deuterostomes. This echinoderm genome provides an evolutionary outgroup for the chordates and yields insights into the evolution of deuterostomes.
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| 3. |
- Haas, Brian J., et al.
(författare)
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Genome sequence and analysis of the Irish potato famine pathogen Phytophthora infestans
- 2009
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 461:7262, s. 393-398
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Tidskriftsartikel (refereegranskat)abstract
- Phytophthora infestans is the most destructive pathogen of potato and a model organism for the oomycetes, a distinct lineage of fungus-like eukaryotes that are related to organisms such as brown algae and diatoms. As the agent of the Irish potato famine in the mid-nineteenth century, P. infestans has had a tremendous effect on human history, resulting in famine and population displacement(1). To this day, it affects world agriculture by causing the most destructive disease of potato, the fourth largest food crop and a critical alternative to the major cereal crops for feeding the world's population(1). Current annual worldwide potato crop losses due to late blight are conservatively estimated at $6.7 billion(2). Management of this devastating pathogen is challenged by its remarkable speed of adaptation to control strategies such as genetically resistant cultivars(3,4). Here we report the sequence of the P. infestans genome, which at similar to 240 megabases (Mb) is by far the largest and most complex genome sequenced so far in the chromalveolates. Its expansion results from a proliferation of repetitive DNA accounting for similar to 74% of the genome. Comparison with two other Phytophthora genomes showed rapid turnover and extensive expansion of specific families of secreted disease effector proteins, including many genes that are induced during infection or are predicted to have activities that alter host physiology. These fast-evolving effector genes are localized to highly dynamic and expanded regions of the P. infestans genome. This probably plays a crucial part in the rapid adaptability of the pathogen to host plants and underpins its evolutionary potential.
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| 4. |
- Koch, Felix-Sebastian, 1977-
(författare)
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Stress and Obesity in Childhood
- 2009
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Childhood obesity is a serious health problem and prevalence increases dramatically around the world, including Sweden. The aim of the current thesis was to examine parents’ and children’s stress in relation to childhood obesity. Parenting stress, social support, parental worries, and serious life events, as well as children’s temperament, self-esteem, body dissatisfaction, saliva cortisol, weight and height were measured to estimate stress and the relation between stress and childhood obesity. Data was collected as part of the cohort project All Babies in Southeast Sweden (ABIS) which main aim is to understand the causes of Type 1 Diabetes. All 21700 children born between October 1997 and October 1999 in Southeast Sweden and their parents were invited to participate and questionnaires were completed for 16070 children at birth. Questionnaires were then collected at follow-ups at 1 year (N=11078), at 2-3 years (N=8803), at 5-6 years (N=7443), and at 8 years (N=3959). The main findings were a relation between parents’ psychological stress and lower self-esteem of children, a relation between parenting stress and higher cortisol levels of children, and a relation between children’s body dissatisfaction and lower self-esteem. Another main finding was a relation between cumulative psychological stress and an increased prevalence of childhood obesity. The current thesis summarized these results, found good validity of the instruments, and the analyses did not indicate any systematic attrition due to stress. It is concluded that the psychological variables reported by parents can be used as proxies for children’s experience of stress in epidemiological studies such as ABIS, and that psychological stress seems to be a contributing factor in childhood obesity. This relation needs to be studied further in order to better understand and intervene in the current epidemic of childhood obesity. These findings may also help to better examine if psychological stress and childhood obesity are contributing factors in the etiology of Type 1 Diabetes.
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| 5. |
- Aggerstam, Thomas, et al.
(författare)
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Investigation of the interface properties of MOVPE grown AlGaN/GaN high electron mobility transistor (HEMT) structures on sapphire
- 2006
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Ingår i: Thin Solid Films. - : Elsevier BV. - 0040-6090 .- 1879-2731. ; 515:2, s. 705-707
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Tidskriftsartikel (refereegranskat)abstract
- We have developed a virtual GaN substrate on sapphire based on a two-step growth method. By optimizing the growth scheme for the virtual substrate we have improved crystal quality and reduced interface roughness. Our Al0.22Ga0.78N/GaN HEMT structure grown on the optimized semi-insulating GaN virtual substrate, exhibits Hall mobilities as high as 1720 and 7350 cm(2)/Vs and sheet carrier concentrations of 8.4 x 1012 and 10.0 x 1012 cm(-2) at 300 K and 20 K, respectively The presence of good AlGaN/GaN interface quality and surface morphology is also substantiated by X-Ray reflectivity and Atomic Force Microscopy measurements. A simplified transport model is used to fit the experimental Hall mobility.
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| 6. |
- Darakchieva, V., et al.
(författare)
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Phonons in strained AlGaN/GaN superlattices
- 2007
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Ingår i: Physica Status Solidi. C, Current topics in solid state physics. - : Wiley. - 1610-1634 .- 1610-1642. ; 4:1, s. 170-174
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Tidskriftsartikel (refereegranskat)abstract
- Phonons in strained AlGaN/GaN superlattices (SLs) with constant periods but different Al composition have been studied using a combination of infrared spectroscopic ellipsometry and Raman scattering spectroscopy. The following SL modes were identified: i) AlGaN localized E1(TO) modes identified for the first time and AlGaN localized A1 (LO) phonons; ii) GaN localized E2, E1(TO) and A1(LO) phonons; iii) delocalized E1(LO) phonons; iv) A1(TO) phonon; v) two modes around 660 cm-1 and 594-625 cm-1, respectively, not predicted by theory. The effects of strain and composition on the phonon frequencies were established and discussed.
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| 7. |
- Fox, A, et al.
(författare)
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Large particles are responsible for elevated bacterial marker levels in school air upon occupation
- 2005
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Ingår i: Journal of Environmental Monitoring. - : Royal Society of Chemistry (RSC). - 1464-0325 .- 1464-0333. ; 7:5, s. 450-456
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Tidskriftsartikel (refereegranskat)abstract
- Muramic acid (Mur) is found in bacterial peptidoglycan ( PG) whereas 3-hydroxy fatty acids (3-OH FAs) are found in Gram-negative bacterial lipopolysaccharide (LPS). Thus Mur and 3-OH FAs serve as markers to assess bacterial levels in indoor air. An initial survey, in a school, demonstrated that the levels of dust, PG and LPS (pmol m(-3)) were each much higher in occupied rooms than in the same rooms when unoccupied. In each instance, the Mur content of dust was increased and the hydroxy fatty acid distribution changed similarly suggesting an alteration in the bacterial population. Here, findings are compared with results from two additional schools. Follow-up aerosol monitoring by particle size was also performed for the first time for all 3 schools. The particle size distribution was shown to be quite different in occupied versus unoccupied schoolrooms. Within individual classrooms, concentrations of airborne particles ≥ 0.8 μ m in diameter, and CO2 were correlated. This suggests that the increased levels of larger particles are responsible for elevation of bacterial markers during occupation. Release of culturable and non-culturable bacteria or bacterial aggregates from children (e.g. from flaking skin) might explain this phenomenon.
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| 8. |
- Gonzalez-Pintor, Sebastian, 1983, et al.
(författare)
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High Order Finite Element Method for the Lambda modes problem on hexagonal geometry
- 2009
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Ingår i: Annals of Nuclear Energy. - : Elsevier BV. - 0306-4549 .- 1873-2100. ; 36:9, s. 1450-1462
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Tidskriftsartikel (refereegranskat)abstract
- A High Order Finite Element Method to approximate the Lambda modes problem for reactors with hexagonal geometry has been developed. This method is based on the expansion of the neutron flux in terms of the modified Dubiner's polynomials on a triangular mesh. This mesh is fixed and the accuracy of the method is improved increasing the degree of the polynomial expansions without the necessity of remeshing. The performance of method has been tested obtaining the dominant Lambda modes of different 2D reactor benchmark problems. © 2009 Elsevier Ltd. All rights reserved.
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| 9. |
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| 10. |
- Maddika, Subbareddy, et al.
(författare)
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Interaction with PI3-kinase contributes to the cytotoxic activity of Apoptin
- 2008
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Ingår i: Oncogene. - : Nature Publishing Group. - 0950-9232 .- 1476-5594. ; 27, s. 3060-3065
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Tidskriftsartikel (refereegranskat)abstract
- Apoptin, a small protein from the chicken anemia virus, has attracted attention because of its specificity in killing tumor cells. Localization of apoptin in the nucleus of tumor cells has been shown to be vital for proapoptotic activity, however, targeted expression of apoptin in the nucleus of normal cells does not harm the cells, indicating that nuclear localization of apoptin is insufficient for its cytotoxicity. Here, we demonstrate for the first time that apoptin interacts with the SH3 domain of p85, the regulatory subunit of phosphoinositide 3-kinase (PI3-K), through its proline-rich region. Apoptin derivatives devoid of this proline-rich region do not interact with p85, are unable to activate PI3-K, and show impaired apoptosis induction. Moreover, apoptin mutants containing the proline-rich domain are sufficient to elevate PI3-K activity and to induce apoptosis in cancer cells. Downregulation of p85 leads to nuclear exclusion of apoptin and impairs cell death induction, indicating that interaction with the p85 PI3-K subunit essentially contributes to the cytotoxic activity of apoptin.
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