| 11. |
- Solano, E. R., et al.
(author)
-
ELMS and strike point jumps
- 2005
-
In: Journal of Nuclear Materials. - : Elsevier BV. - 0022-3115 .- 1873-4820. ; 337-39:03-jan, s. 747-750
-
Journal article (peer-reviewed)abstract
- If an ELM is a peeling of flux surfaces from the plasma, due to a broken separatrix, current density is lost as well as particles and energy. The fast loss of a current-carrying plasma layer modifies the plasma equilibrium, leading to sudden shifts in the strike points at each ELM, towards the plasma centre. An experimental study of this conjectured model of the ELM has been made at JET, showing that in all cases of Type I ELMs studied, strike point shifts were observed. In two cases studied in detail, the estimated equilibrium changes provoked by flux surface peeling agree qualitatively with the observed strike point shifts.
|
|
| 12. |
- Strachan, J. D., et al.
(author)
-
Modelling of carbon migration during JET C-13 injection experiments
- 2008
-
In: Nuclear Fusion. - : IOP Publishing. - 0029-5515 .- 1741-4326. ; 48:10
-
Journal article (peer-reviewed)abstract
- JET has performed two dedicated carbon migration experiments on the final run day of separate campaigns ( 2001 and 2004) using (CH4)-C-13 methane injected into repeated discharges. The EDGE2D/NIMBUS code modelled the carbon migration in both experiments. This paper describes this modelling and identifies a number of important migration pathways: ( 1) deposition and erosion near the injection location, ( 2) migration through the main chamber SOL, (3) migration through the private flux region (PFR) aided by E x B drifts and ( 4) neutral migration originating near the strike points. In H-Mode, type I ELMs are calculated to influence the migration by enhancing erosion during the ELM peak and increasing the long-range migration immediately following the ELM. The erosion/re-deposition cycle along the outer target leads to a multistep migration of C-13 towards the separatrix which is called 'walking'. This walking created carbon neutrals at the outer strike point and led to 13C deposition in the PFR. Although several migration pathways have been identified, quantitative analyses are hindered by experimental uncertainty in divertor leakage, and the lack of measurements at locations such as gaps and shadowed regions.
|
|
| 13. |
- Ainsworth, Elizabeth A., et al.
(author)
-
Next generation of elevated [CO2] experiments with crops: a critical investment for feeding the future world
- 2008
-
In: Plant, Cell and Environment. - : Wiley. - 0140-7791 .- 1365-3040. ; 31:9, s. 1317-1324
-
Journal article (peer-reviewed)abstract
- A rising global population and demand for protein-rich diets are increasing pressure to maximize agricultural productivity. Rising atmospheric [CO2] is altering global temperature and precipitation patterns, which challenges agricultural productivity. While rising [CO2] provides a unique opportunity to increase the productivity of C-3 crops, average yield stimulation observed to date is well below potential gains. Thus, there is room for improving productivity. However, only a fraction of available germplasm of crops has been tested for CO2 responsiveness. Yield is a complex phenotypic trait determined by the interactions of a genotype with the environment. Selection of promising genotypes and characterization of response mechanisms will only be effective if crop improvement and systems biology approaches are closely linked to production environments, that is, on the farm within major growing regions. Free air CO2 enrichment (FACE) experiments can provide the platform upon which to conduct genetic screening and elucidate the inheritance and mechanisms that underlie genotypic differences in productivity under elevated [CO2]. We propose a new generation of large-scale, low-cost per unit area FACE experiments to identify the most CO2-responsive genotypes and provide starting lines for future breeding programmes. This is necessary if we are to realize the potential for yield gains in the future.
|
|
| 14. |
- Hobirk, J., et al.
(author)
-
Improved confinement in JET hybrid discharges
- 2009
-
In: 36th EPS Conference on Plasma Physics 2009, EPS 2009 - Europhysics Conference Abstracts. - 9781622763368 ; , s. 150-153
-
Conference paper (peer-reviewed)
|
|
| 15. |
- Jeppsson, Lennart, et al.
(author)
-
High-resolution Late Silurian correlations between Gotland, Sweden and the Broken River region, NE Australia: Lithologies, conodonts and isotopes
- 2007
-
In: Palaeogeography, Palaeoclimatology, Palaeoecology. - : Elsevier BV. - 0031-0182 .- 1872-616X. ; 245:1-2, s. 115-137
-
Conference paper (peer-reviewed)abstract
- High-resolution correlations, partly with a precision better than 10 ka, are achieved between late Ludfordian sequences on Gotland, Sweden (on Baltica), and a section (COG) through the Coral Gardens Formation along the Broken River, northeastern Australia (on Gondwana), despite these sections having been on different palaeocontinents facing different oceans. The interval is characterised by rapid, very large faunal, isotopic, and lithologic changes. Lithologies are remarkably similar in the two areas, consisting of, in order from below: marls with thin limestone beds, flaggy limestones, oncoidal crinoidal limestone, oncoidal marls, terrigenous clastics (silty clay, mudstone, sandstone), oolite, and cliff-/gorge-forming limestones. Further, independent correlation dates several of the lithological changes as coeval. The 813 C excursion in whole rock carbonates is one of the three largest ones known during the Phanerozoic. The increase in delta C-13 is very similar in the two areas, from below + 1 parts per thousand to c. + 9 parts per thousand VPDB though two Gotland samples yielded + 9.71 parts per thousand and + 10.54 parts per thousand (the corresponding COG interval included fewer carbonate layers than needed to definitely exclude that this difference is due to a lack of suitable rocks for sampling). Compared with the lithologies and the delta C-13 curves, the conodont faunas display some divergence, but key taxa permit precise correlations for much of the studied interval. The conodont assemblages change stepwise from very diverse in the Polygnathoides siluricus Zone to a low diversity fauna dominated markedly by a single taxon (Upper Icriodontid Subzone), returning abruptly to a comparatively diverse Ozarkodina snajdri Zone fauna. A method resembling graphic correlation in some respects is used to propose a similarly high-resolution correlation through a longer interval for future testing. (c) 2006 Elsevier B.V. All rights reserved.
|
|
| 16. |
- Ong, Ken K., et al.
(author)
-
Genetic variation in LIN28B is associated with the timing of puberty
- 2009
-
In: Nature Genetics. - : Springer Science and Business Media LLC. - 1061-4036 .- 1546-1718. ; 41:6, s. 729-733
-
Journal article (peer-reviewed)abstract
- The timing of puberty is highly variable(1). We carried out a genome-wide association study for age at menarche in 4,714 women and report an association in LIN28B on chromosome 6 (rs314276, minor allele frequency (MAF) = 0.33, P = 1.5 x 10(-8)). In independent replication studies in 16,373 women, each major allele was associated with 0.12 years earlier menarche (95% CI = 0.08-0.16; P = 2.8 x 10(-10); combined P = 3.6 x 10(-16)). This allele was also associated with earlier breast development in girls (P = 0.001; N = 4,271); earlier voice breaking (P = 0.006, N = 1,026) and more advanced pubic hair development in boys (P = 0.01; N = 4,588); a faster tempo of height growth in girls (P = 0.00008; N = 4,271) and boys (P = 0.03; N = 4,588); and shorter adult height in women (P = 3.6 x 10(-7); N = 17,274) and men (P = 0.006; N = 9,840) in keeping with earlier growth cessation. These studies identify variation in LIN28B, a potent and specific regulator of microRNA processing(2), as the first genetic determinant regulating the timing of human pubertal growth and development.
|
|
| 17. |
- Richards, Stephen, et al.
(author)
-
The genome of the model beetle and pest Tribolium castaneum.
- 2008
-
In: Nature. - 1476-4687. ; 452:7190, s. 949-55
-
Journal article (peer-reviewed)abstract
- Tribolium castaneum is a representative of earth’s most numerous eukaryotic order, a powerful model organism for the study of generalized insect development, and also an important pest of stored agricultural products. We describe its genome sequence here. This omnivorous beetle has evolved an ability to interact with a diverse chemical environment as evidenced by large expansions in odorant and gustatory receptors, as well as p450 and other detoxification enzymes. Developmental patterns in Tribolium are more representative of other arthropods than those found in Drosophila, a fact represented in gene content and function. For one, Tribolium has retained more ancestral genes involved in cell-cell communication than Drosophila, and some are expressed in the growth zone crucial for axial elongation in short germ development. Systemic RNAi in T. castaneum appears to use mechanisms distinct from those found in C. elegans, but nevertheless offers similar power for the elucidation of gene function and identification of targets for selective insect control.
|
|
| 18. |
- Salanti, Georgia, et al.
(author)
-
Underlying Genetic Models of Inheritance in Established Type 2 Diabetes Associations
- 2009
-
In: American Journal of Epidemiology. - : Oxford University Press (OUP). - 0002-9262 .- 1476-6256. ; 170:5, s. 537-545
-
Research review (peer-reviewed)abstract
- For most associations of common single nucleotide polymorphisms (SNPs) with common diseases, the genetic model of inheritance is unknown. The authors extended and applied a Bayesian meta-analysis approach to data from 19 studies on 17 replicated associations with type 2 diabetes. For 13 SNPs, the data fitted very well to an additive model of inheritance for the diabetes risk allele; for 4 SNPs, the data were consistent with either an additive model or a dominant model; and for 2 SNPs, the data were consistent with an additive or recessive model. Results were robust to the use of different priors and after exclusion of data for which index SNPs had been examined indirectly through proxy markers. The Bayesian meta-analysis model yielded point estimates for the genetic effects that were very similar to those previously reported based on fixed- or random-effects models, but uncertainty about several of the effects was substantially larger. The authors also examined the extent of between-study heterogeneity in the genetic model and found generally small between-study deviation values for the genetic model parameter. Heterosis could not be excluded for 4 SNPs. Information on the genetic model of robustly replicated association signals derived from genome-wide association studies may be useful for predictive modeling and for designing biologic and functional experiments.
|
|
| 19. |
- Solano, E. R., et al.
(author)
-
ELMs and strike point movements
- 2008
-
In: Nuclear Fusion. - : IOP Publishing. - 0029-5515 .- 1741-4326. ; 48:6
-
Journal article (peer-reviewed)abstract
- A detailed study of position changes of plasma strike points before and after edge localized modes (ELMs) in JET was carried out. A hypothesis being tested is that in an ELM previously closed edge field lines would open up, releasing plasma current and leading to the formation of a new, smaller separatrix. It was observed that after each ELM strike points have shifted a few centimetres towards the plasma centre ( up in JET). In some cases a transient (< 100 mu s), upwards large (> 10 cm) jump of strike positions was observed first. It was followed by an equally fast jump down to the shifted strike positions. Such behaviour has not been described in previous computational models of the ELM. Therefore two novel instability mechanisms are presented, which contribute to explain the changes in strike point position: an X-point instability, due to positive toroidal current density at the X-point, and a diamagnetic instability, due to negative inboard toroidal current density.
|
|
| 20. |
- Szatmari, Peter, et al.
(author)
-
Mapping autism risk loci using genetic linkage and chromosomal rearrangements.
- 2007
-
In: Nature Genetics. - : Springer Science and Business Media LLC. - 1061-4036 .- 1546-1718. ; 39:3, s. 319-328
-
Journal article (peer-reviewed)abstract
- Autism spectrum disorders (ASDs) are common, heritable neurodevelopmental conditions. The genetic architecture of ASDs is complex, requiring large samples to overcome heterogeneity. Here we broaden coverage and sample size relative to other studies of ASDs by using Affymetrix 10K SNP arrays and 1,168 families with at least two affected individuals, performing the largest linkage scan to date while also analyzing copy number variation in these families. Linkage and copy number variation analyses implicate chromosome 11p12-p13 and neurexins, respectively, among other candidate loci. Neurexins team with previously implicated neuroligins for glutamatergic synaptogenesis, highlighting glutamate-related genes as promising candidates for contributing to ASDs.
|
|
