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| 2. |
- Gjestvang, D., et al.
(författare)
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Examination of how properties of a fissioning system impact isomeric yield ratios of the fragments
- 2023
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Ingår i: Physical Review C. - : American Physical Society. - 2469-9985 .- 2469-9993. ; 108:6
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Tidskriftsartikel (refereegranskat)abstract
- The population of isomeric states in the prompt decay of fission fragments-so-called isomeric yield ratios (IYRs)-is known to be sensitive to the angular momentum J that the fragment emerged with, and may therefore contain valuable information on the mechanism behind the fission process. In this work, we investigate how changes in the fissioning system impact the measured IYRs of fission fragments to learn more about what parameters affect angular momentum generation. To enable this, a new technique for measuring IYRs is first demonstrated. It is based on the time of arrival of discrete gamma rays, and has the advantage that it enables the study of the IYR as a function of properties of the partner nucleus. This technique is used to extract the IYR of 134Te, strongly populated in actinide fission, from the three different fissioning systems: 232Th(n, f), 238U(n, f), at two different neutron energies, as well as 252Cf(sf). The impacts of changing the fissioning system, the compound nuclear excitation energy, the minimum J of the binary partner, and the number of neutrons emitted on the IYR of 134Te are determined. The decay code TALYS is used in combination with the fission simulation code FREYA to calculate the primary fragment angular momentum from the IYR. We find that the IYR of 134Te has a slope of 0.004 +/- 0.002 with increase in compound nucleus (CN) mass. When investigating the impact on the IYR of increased CN excitation energy, we find no change with an energy increase similar to the difference between thermal and fast fission. By varying the mass of the partner fragment emerging with 134Te, it is revealed that the IYR of 134Te is independent of the total amount of prompt neutrons emitted from the fragment pair. This indicates that neutrons carry minimal angular momentum away from the fission fragments. Comparisons with the FREYA+TALYS simulations reveal that the average angular momentum in 134Te following 238U(n, f) is 6.0 h over bar . This is not consistent with the value deduced from recent CGMF calculations. Finally, the IYR sensitivity to the angular momentum of the primary fragment is discussed. These results are not only important to help understanding the underlying mechanism in nuclear fission, but can also be used to constrain and benchmark fission models, and are relevant to the gamma -ray heating problem of reactors.
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| 3. |
- Morrison, L., et al.
(författare)
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Dealing with contaminants in Coulomb excitation of radioactive beams
- 2020
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Ingår i: 27th International Nuclear Physics Conference (INPC2019) 29 July - 2 August 2019, Glasgow, UK. - : IOP Publishing. - 1742-6588. ; 1643
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Konferensbidrag (refereegranskat)abstract
- Data analysis of the Coulomb excitation experiment of the exotic 206Hg nucleus, recently performed at CERN's HIE-ISOLDE facility, needs to account for the contribution to target excitation due to the strongly-present beam contaminant 130Xe. In this paper, the contamination subtraction procedure is presented.
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| 4. |
- Morrison, L., et al.
(författare)
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Quadrupole and octupole collectivity in the semi-magic nucleus 20680Hg126
- 2023
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Ingår i: Physics Letters B. - : Elsevier BV. - 0370-2693. ; 838
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Tidskriftsartikel (refereegranskat)abstract
- The first low-energy Coulomb-excitation measurement of the radioactive, semi-magic, two proton-hole nucleus 206Hg, was performed at CERN's recently-commissioned HIE-ISOLDE facility. Two γ rays depopulating low-lying states in 206Hg were observed. From the data, a reduced transition strength B(E2; 2+1 → 0+1) = 4.4(6) W.u. was determined, the first such value for an N=126 nucleus south of 208Pb, which is found to be slightly lower than that predicted by shell-model calculations. In addition, a collective octupole state was identified at an excitation energy of 2705 keV, for which a reduced B(E3) transition probability of 30+10-30 W.u. was extracted. These results are crucial for understanding both quadrupole and octupole collectivity in the vicinity of the heaviest doubly-magic nucleus 208Pb, and for benchmarking a number of theoretical approaches in this key region. This is of particular importance given the paucity of data on transition strengths in this region, which could be used, in principle, to test calculations relevant to the astrophysical r-process.
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| 5. |
- Morrison, L., et al.
(författare)
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Quadrupole deformation of Xe 130 measured in a Coulomb-excitation experiment
- 2020
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Ingår i: Physical Review C. - 2469-9985. ; 102:5
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Tidskriftsartikel (refereegranskat)abstract
- Low-lying states in the isotope Xe130 were populated in a Coulomb-excitation experiment performed at CERN's HIE-ISOLDE facility. The magnitudes and relative signs of seven E2 matrix elements and one M1 matrix element coupling five low-lying states in Xe130 were determined using the semiclassical coupled-channel Coulomb-excitation least-squares search code gosia. The diagonal E2 matrix elements of both the 21+ and 41+ states were extracted for the first time. The reduced transition strengths are in line with those obtained from previous measurements. Experimental results were compared with the general Bohr Hamiltonian with the microscopic input from mean-field theory utilizing universal nuclear energy density functional (UNEDF0), shell-model calculations using the GCN50:82 and SN100PN interactions, and simple phenomenological models (Davydov-Filippov and γ-soft). The extracted shape parameters indicate triaxial-prolate deformation in the ground-state band. In general, good agreement between theoretical predictions and experimental values was found, while neither phenomenological model was found to provide an adequate description of Xe130.
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| 6. |
- Costa, D, et al.
(författare)
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Factors associated with quality of services for marginalized groups with mental health problems in 14 European countries
- 2014
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Ingår i: BMC Health Services Research. - : Springer Science and Business Media LLC. - 1472-6963. ; , s. Art. no. 49-
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Tidskriftsartikel (refereegranskat)abstract
- Background:Different service characteristics are known to influence mental health care delivery. Much less isknown about the impact of contextual factors, such as the socioeconomic circumstances, on the provision of careto socially marginalized groups.The objectives of this work were to assess the organisational characteristics of services providing mental health carefor marginalized groups in 14 European capital cities and to explore the associations between organisationalquality, service features and country-level characteristics.Methods:617 services were assessed in two highly deprived areas in 14 European capital cities. A Quality Index ofService Organisation (QISO) was developed and applied across all sites. Service characteristics and country levelsocioeconomic indicators were tested and related with the Index using linear regressions and random interceptlinear models.Results:The mean (standard deviation) of the QISO score (minimum = 0; maximum = 15) varied from 8.63 (2.23) inIreland to 12.40 (2.07) in Hungary. The number of different programmes provided was the only service characteristicsignificantly correlated with the QISO (p < 0.05). The national Gross Domestic Product (GDP) was inverselyassociated with the QISO. Nearly 15% of the variance of the QISO was attributed to country-level variables, withGDP explaining 12% of this variance.Conclusions:Socioeconomic contextual factors, in particular the national GDP are likely to influence theorganisational quality of services providing mental health care for marginalized groups. Such factors should beconsidered in international comparative studies. Their significance for different types of services should be exploredin further research.Keywords:Mental health services, Quality index of service organization, Socially marginalized groups,Multi-level analysis
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| 8. |
- De Neve, Jan-Walter, et al.
(författare)
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Are out-of-school adolescents at higher risk of adverse health outcomes? Evidence from 9 diverse settings in sub-Saharan Africa
- 2020
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Ingår i: Tropical Medicine & International Health. - : Wiley. - 1365-3156 .- 1360-2276. ; 25:1, s. 70-80
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: We analysed mutually comparable surveys on adolescent attitudes and behaviours from nine sites in seven sub‐Saharan African countries, to determine the relationship between school enrolment and adolescent health outcomes.Methods: Data from the Africa Research, Implementation Science, and Education Network cross‐sectional adolescent health surveys were used to examine the associations of current school enrolment, self‐reported general health and four major adolescent health domains: (i) sexual and reproductive health; (ii) nutrition and non‐communicable diseases; (iii) mental health, violence and injury; and (iv) healthcare utilisation. We used multivariable Poisson regression models to calculate relative risk ratios with 95% confidence intervals (CI), controlling for demographic and socio‐economic characteristics. We assessed heterogeneity by gender and study site.Results: Across 7829 adolescents aged 10–19, 70.5% were in school at the time of interview. In‐school adolescents were 14.3% more likely (95% CI: 6–22) to report that their life is going well; 51.2% less likely (95% CI: 45–67) to report ever having had sexual intercourse; 32.6% more likely (95% CI: 9–61) to report unmet need for health care; and 30.1% less likely (95% CI: 15–43) to report having visited a traditional healer. School enrolment was not significantly associated with malnutrition, low mood, violence or injury. Substantial heterogeneity was identified between genders for sexual and reproductive health, and in‐school adolescents were particularly less likely to report adverse health outcomes in settings with high average school enrolment.Conclusions: School enrolment is strongly associated with sexual and reproductive health and healthcare utilisation outcomes across nine sites in sub‐Saharan Africa. Keeping adolescents in school may improve key health outcomes, something that can be explored through future longitudinal, mixed‐methods, and (quasi‐)experimental studies.
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| 9. |
- Doody, A., et al.
(författare)
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Validating the association between plasma tumour necrosis factor receptor 1 levels and the presence of renal injury and functional decline in patients with Type 2 diabetes
- 2018
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Ingår i: Journal of Diabetes and Its Complications. - : Elsevier BV. - 1056-8727. ; 32:1, s. 95-99
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Tidskriftsartikel (refereegranskat)abstract
- Aims: Elevated plasma soluble tumour necrosis factor receptor 1 (TNFR1) predicts long-term progression of chronic kidney disease. We investigated the association between elevated TNFR1 and the presence of renal disease in patients with Type 2 diabetes mellitus registering a haemoglobin Mc (HbA1c) >48 mmol/mol despite medical therapy. Methods: Using sensitivity, specificity and regression analyses we interrogated the association between plasma TNFR1 and presence of chronic kidney disease as assessed by the presence of microalbuminuria and/or an estimated glomerular filtration rate of less than 60 ml/min/1.73 m(2) (stages 3-5 chronic kidney disease). The association of TNFR1 with C-reactive protein and leptin-adiponectin ratio as plasma markers of systemic inflammation and adipose stress respectively was also investigated. Results: Upper quartile TNFR1 is independently associated with elevated urinary albumin-creatinine ratios, reductions in eGFR and strongly predicts the presence of stages 3-5 chronic kidney disease in regression modelling. Elevated TNFR1 levels are associated with increased plasma C-reactive protein and augmented leptin-adiponectin ratio. Conclusions: Our study confirms plasma TNFR1 as a surrogate of renal structural and functional impairment in patients with type 2 diabetes mellitus. Association of TNFR1 with markers of systemic inflammation and adipose stress indicates that TNFR1 may be a biomarker of these processes as components of the pathogenesis of diabetic kidney disease. (C) 2017 Elsevier Inc. All rights reserved.
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| 10. |
- Graham, Jesse R., et al.
(författare)
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The pipeline project: Pre-publication independent replications of a single laboratory's research pipeline
- 2016
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Ingår i: Journal of Experimental Social Psychology. - : Elsevier. - 1096-0465 .- 0022-1031. ; 66, s. 55-67
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Tidskriftsartikel (refereegranskat)abstract
- This crowdsourced project introduces a collaborative approach to improving the reproducibility of scientific research, in which findings are replicated in qualified independent laboratories before (rather than after) they are published. Our goal is to establish a non-adversarial replication process with highly informative final results. To illustrate the Pre-Publication Independent Replication (PPIR) approach, 25 research groups conducted replications of all ten moral judgment effects which the last author and his collaborators had “in the pipeline” as of August 2014. Six findings replicated according to all replication criteria, one finding replicated but with a significantly smaller effect size than the original, one finding replicated consistently in the original culture but not outside of it, and two findings failed to find support. In total, 40% of the original findings failed at least one major replication criterion. Potential ways to implement and incentivize pre-publication independent replication on a large scale are discussed.
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