| 1. |
- Mason, P, et al.
(författare)
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Octupole signatures in Ba-124,Ba-125
- 2005
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Ingår i: Journal of Physics G. - : IOP Publishing. - 0954-3899 .- 1361-6471. ; 31:10, s. S1729-S1733
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Tidskriftsartikel (refereegranskat)abstract
- The gamma decay of the nuclei Ba-121,Ba-125 has been investigated with the EUROBALL array, using the reaction Ni-64+Ni-64 at E-beam = 255 and 261 MeV. Six new E1 transitions have been found in the nucleus Ba-125, suggesting a significant role of octupole correlations in the origin of its parity doublets. The J(pi) = 3(-) level of the nucleus Ba-124 has been identified for the first time. Its excitation energy is in very good agreement with a prediction based on a microscopic model including octupole interactions.
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| 2. |
- Wilson, A. N., et al.
(författare)
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Magnetic dipole bands in 190Hg : First evidence of excitations across the Z = 82 sub-shell in Hg nuclei
- 2001
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Ingår i: Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics. - 0370-2693. ; 505:1-4, s. 6-14
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Tidskriftsartikel (refereegranskat)abstract
- An experiment aimed at studying high-spin states in 190Hg was performed with the Eurogam II array. The data have revealed the presence of cascades of magnetic dipole transitions with some unexpected properties. Unlike the MI bands previously observed in the heavier Hg isotopes, these structures have extremely large B(M1)/B(E2) ratios, The observation of a third dipole band with much lower B(M1)/B(E2) values in the same spin/excitation energy regime suggests that the bands may represent configurations occurring in different minima in the potential energy surface. Configuration-dependent Cranked Nilsson-Strutinsky calculations predict the presence of a minimum in the nuclear potential energy surface at a deformation of ε ≅ 0.2, γ ≅ -90°, occurring when a proton is excited across the Z = 82 shell-gap into an h9/2 orbital. It is suggested that the bands exhibiting anomalously large B(M1)/B(E2) ratios may be associated with this minimum.
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| 3. |
- Cherif, E., et al.
(författare)
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Evolution of sex chromosomes prior to speciation in the dioecious Phoenix species
- 2016
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Ingår i: Journal of Evolutionary Biology. - : Wiley. - 1010-061X .- 1420-9101. ; 29:8, s. 1513-1522
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Tidskriftsartikel (refereegranskat)abstract
- Understanding the driving forces and molecular processes underlying dioecy and sex chromosome evolution, leading from hermaphroditism to the occurrence of male and female individuals, is of considerable interest in fundamental and applied research. The genus Phoenix, belonging to the Arecaceae family, consists uniquely of dioecious species. Phylogenetic data suggest that the genus Phoenix has diverged from a hermaphroditic ancestor which is also shared with its closest relatives. We have investigated the cessation of recombination in the sex-determination region within the genus Phoenix as a whole by extending the analysis of P.dactylifera SSR sex-related loci to eight other species within the genus. Phylogenetic analysis of a date palm sex-linked PdMYB1 gene in these species has revealed that sex-linked alleles have not clustered in a species-dependent way but rather in X and Y-allele clusters. Our data show that sex chromosomes evolved from a common autosomal origin before the diversification of the extant dioecious species.
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| 4. |
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| 5. |
- Gueorguieva, E., et al.
(författare)
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High-spin states in Au-191 : Evidence for triaxial shape?
- 2003
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Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 68:5, s. 543081-5430814
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Tidskriftsartikel (refereegranskat)abstract
- The level scheme of Au-191 was considerably extended to high spin using gamma spectroscopy with the Eurogam-II array and internal conversion measurements with the Orsay electron spectrometer. Several bands that appear as strongly coupled were associated with low- Omega configurations in Au-191 . Using total routhian surface and cranked shell model calculations it was shown that these bands have a rotation-aligned nature and are most likely generated by the nonaxiallity of the nucleus induced by the odd proton. The predictions for the presence of such bands in Au-191 and in the oblate nuclei in the Pt-Au-Hg region found excellent agreement with the experimental data, as well as the predictions for their alignments and band-crossing frequencies in Au-191 .
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| 6. |
- Gueorguieva, E., et al.
(författare)
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Sets of rotation-aligned bands indicating nonaxiality in Au-190
- 2004
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Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 69:4, s. 044320-
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Tidskriftsartikel (refereegranskat)abstract
- The level scheme of Au-190 was extended up to high spin using gamma spectroscopy with the Eurogam-II array and internal conversion measurements with the electron- gamma spectrometer of Orsay. Several sets of rotation-aligned bands were found and associated with high- j, low- K configurations. According to the total Routhian surface and cranked shell model calculations these bands are caused by the nonaxiality of the nuclear deformation (gammaless than or equal to-70degrees). Furthermore, very good agreement was obtained between the experimental data and the theoretical predictions for the properties of these bands, such as alignments, band-crossing frequencies, and signature inversion, thus supporting the suggested nonaxial shapes.
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| 7. |
- Iqbal, Waheed, et al.
(författare)
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Mean climate and representation of jet streams in the CORDEX South Asia simulations by the regional climate model RCA4
- 2017
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Ingår i: Journal of Theoretical and Applied Climatology. - : Springer Science and Business Media LLC. - 0177-798X .- 1434-4483. ; 129:1-2, s. 1-19
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Tidskriftsartikel (refereegranskat)abstract
- A number of simulations with the fourth release of the Rossby Center Regional Climate Model (RCA4) conducted within the COordinated Regional climate Downscaling EXperiment (CORDEX) framework for South Asia at 50 km horizontal resolution are evaluated for mean winter (December-March) and summer (June-September) climate during 1980-2005. The two driving data sets ERA-Interim reanalysis and the general circulation model EC-Earth have been analyzed besides the RCA4 simulations to address the added value. RCA4 successfully captures the mean climate in both the seasons. The biases in RCA4 appear to come from the driving data sets which are amplified after downscaling. The jet streams influencing the seasonal precipitation variability in both seasons are also analyzed. The spatial and quantitative analysis over CORDEX South Asia generally revealed the ability of RCA4 to capture the mean seasonal climate as well as the position and strength of the jet streams despite weak/strong jet representation in the driving data. The EC-Earth downscaled with RCA4 exhibited cold biases over the domain and a weak Somali jet over the Arabian Sea. Moreover, the moisture transport from the Arabian Sea during summer is pronounced in RCA4 simulations resulting in enhanced monsoon rainfall over northwestern parts of India. Both the Somali jet and the tropical easterly jet become stronger during strong summer monsoon years. However, there is robust impact of wet years in summer over the Somali jet. Wet-minus-dry composites in winter indicate strengthening (weakening) of the subtropical jet in RCA4 run by ERA-Interim (EC-Earth). The driving data have clear reflections on the RCA4 simulations.
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| 8. |
- Latif, M., et al.
(författare)
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Analysis of rainfall trends over Indo-Pakistan summer monsoon and related dynamics based on CMIP5 climate model simulations
- 2018
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Ingår i: International Journal of Climatology. - : Wiley. - 0899-8418 .- 1097-0088. ; 38, s. e577-e595
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Tidskriftsartikel (refereegranskat)abstract
- Understanding the effects of climate change and global warming on the South Asian summer monsoon rainfall trend is critically important for millions of inhabitants of this region. This study investigates seasonal (June-September) rainfall trend over the Indo-Pakistan subcontinent by using 36 climate model outputs from the World Climate Research Programme's Coupled Model Inter-comparison Project Phase 5. The historical (1951-2005) and future (2006-2100) simulations under two representative concentration pathways (RCPs), RCP4.5 and RCP8.5, are analysed for this purpose. Model reproducibility is evaluated based on spatial correlation of seasonal rainfall and vertically integrated meridional moisture transport between simulated and observed fields. It is found that the majority of models shows reasonable skill in capturing the observed pattern of rainfall climatology and trend over the subcontinent. Our results showed that the models are more skilful in simulating seasonal mean moisture transport than trend over the Arabian Sea and Bay of Bengal. Of the 36 models analysed, only two models HadGEM2-AO and CNRM-CM5 closely approximate both the climatology and trend based on statistical performance metrics. Our results suggest that the strengthening of northwards moisture transport over the Arabian Sea and Bay of Bengal is a likely reason for the increasing rainfall trend over Indo-Pakistan subcontinent in a warmer climate. The RCP8.5 indicates marked increase in both rainfall and moisture transport trends compared to RCP4.5 forcing scenario.
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| 9. |
- Latif, Muhammad, et al.
(författare)
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Rainfall trends in the South Asian summer monsoon and its related large-scale dynamics with focus over Pakistan
- 2017
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Ingår i: Climate Dynamics. - : Springer Science and Business Media LLC. - 0930-7575 .- 1432-0894. ; 48:11, s. 3565-3581
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Tidskriftsartikel (refereegranskat)abstract
- The study of regional rainfall trends over South Asia is critically important for food security and economy, as both these factors largely depend on the availability of water. In this study, South Asian summer monsoon rainfall trends on seasonal and monthly (June-September) time scales have been investigated using three observational data sets. Our analysis identify a dipole-type structure in rainfall trends over the region north of the Indo-Pak subcontinent, with significant increasing trends over the core monsoon region of Pakistan and significant decreasing trends over the central-north India and adjacent areas. The dipole is also evident in monthly rainfall trend analyses, which is more prominent in July and August. We show, in particular, that the strengthening of northward moisture transport over the Arabian Sea is a likely reason for the significant positive trend of rainfall in the core monsoon region of Pakistan. In contrast, over the central-north India region, the rainfall trends are significantly decreasing due to the weakening of northward moisture transport over the Bay of Bengal. The leading empirical orthogonal functions clearly show the strengthening (weakening) patterns of vertically integrated moisture transport over the Arabian Sea (Bay of Bengal) in seasonal and monthly interannual time scales. The regression analysis between the principal components and rainfall confirm the dipole pattern over the region. Our results also suggest that the extra-tropical phenomena could influence the mean monsoon rainfall trends over Pakistan by enhancing the cross-equatorial flow of moisture into the Arabian Sea.
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| 10. |
- Syed, F. S., et al.
(författare)
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Inter-annual variability of moisture transport over the northern Indian Ocean and South Asian summer monsoon
- 2018
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Ingår i: Climate Research (CR). - : Inter-Research Science Center. - 0936-577X .- 1616-1572. ; 75:1, s. 23-31
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Tidskriftsartikel (refereegranskat)abstract
- We studied the inter-annual variability of the vertically integrated zonal/meridional moisture transport in the lower troposphere over the northern Indian Ocean using observed data from 1971-2016 for the South Asian summermon soon (SASM) season. The moisture transport variability was dominated by the zonal component associated with the Somali low level jet. For identification of the dominant modes of inter-annual variability, 3-dimensional empirical ortho gonal function analysis was performed. The leading mode, associated with suppressed meridional moisture transport in both the Arabian Sea and Bay of Bengal and increased zonal moisture transport over the Bay of Bengal, was linked with the positive phase of the Indian Ocean dipole and El Nino conditions in the Pacific Ocean. The second leading mode was associated with the enhanced zonal moisture flow over the Arabian Sea extending up to the Bay of Bengal allied with the Somali low level jet, and enhanced northeastward moisture transport over the whole region. This enhanced moisture flow results in stronger monsoon circulation and increased rainfall over South Asia.
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