| 1. |
- Reifarth, R., et al.
(författare)
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Nuclear astrophysics with radioactive ions at FAIR
- 2016
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Ingår i: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 665:1
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Konferensbidrag (refereegranskat)abstract
- The nucleosynthesis of elements beyond iron is dominated by neutron captures in the s and r processes. However, 32 stable, proton-rich isotopes cannot be formed during those processes, because they are shielded from the s-process flow and r-process beta-decay chains. These nuclei are attributed to the p and rp process. For all those processes, current research in nuclear astrophysics addresses the need for more precise reaction data involving radioactive isotopes. Depending on the particular reaction, direct or inverse kinematics, forward or time-reversed direction are investigated to determine or at least to constrain the desired reaction cross sections. The Facility for Antiproton and Ion Research (FAIR) will offer unique, unprecedented opportunities to investigate many of the important reactions. The high yield of radioactive isotopes, even far away from the valley of stability, allows the investigation of isotopes involved in processes as exotic as the r or rp processes.
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| 2. |
- McCall, Matthew B B, et al.
(författare)
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Persistence of full-length caspase-12 and its relation to malaria in West and Central African populations
- 2010
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Ingår i: European Cytokine Network. - 1148-5493 .- 1952-4005. ; 21:2, s. 77-83
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Tidskriftsartikel (refereegranskat)abstract
- Background. The full-length (L-) variant of caspase-12 is believed to predispose to sepsis. It has been replaced in the genome of most human populations by the (S-) variant, which leads to premature termination of translation. Strikingly, the L-allele is still widely prevalent in African populations, presumably due to a counterbalancing selective force specific to this continent, for which malaria is a prime candidate.Methods. We investigated associations between caspase-12 genotype and malarial parameters in three West-African populations, in studies encompassing immunological, clinical and obstetric data. Results. The caspase-12 L-allele was found at frequencies of 11-34%. Plasmodium falciparum-stimulated mononuclear cells from S/L heterozygote donors produced stronger interferon-γ and interleukin-10 responses than S/S homozygotes (p = 0.011 and p = 0.023 in uninfected and infected donors respectively). Nevertheless, we found no association between caspase-12 genotype and either the presentation of severe malaria or individual clinical parameters in sick children. Amongst pregnant women, the caspase-12 genotype did not influence peripheral or placental malaria infection, or basic obstetric parameters. Interestingly, perinatal mortality was more frequent in children of both S/S and L/L than S/L mothers, independent of placental P. falciparum-infection.Conclusion. We find little clinical or epidemiological evidence that malaria has contributed to the persistence of functional caspase-12 in Africa, suggesting either that alternative selective forces are at work or that genetic drift underlies its current global distribution.
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| 3. |
- Wojcik, Andrzej, et al.
(författare)
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Chromosomal aberrations in peripheral blood lymphocytes exposed to a mixed beam of low energy neutrons and gamma radiation
- 2012
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Ingår i: Journal of Radiological Protection. - : IOP Publishing. - 0952-4746 .- 1361-6498. ; 32:3, s. 261-274
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Tidskriftsartikel (refereegranskat)abstract
- Cells exposed to thermal neutrons are simultaneously damaged by radiations with high and low linear energy transfer (LET). A question relevant for the assessment of risk of exposure to a mixed beam is whether the biological effect of both radiation types is additive or synergistic. The aim of the present investigation was to calculate whether the high and low LET components of a thermal neutron field interact when damaging cells. Human peripheral blood lymphocytes were exposed to neutrons from the HB11 beam at the Institute for Energy and Transport, Petten, Netherlands, in a 37 degrees C water phantom at varying depths, where the mix of high and low LET beam components differs. Chromosomal aberrations were analysed and the relative biological effectiveness (RBE) values as well as the expected contributions of protons and photons to the aberration yield were calculated based on a dose response of aberrations in lymphocytes exposed to Co-60 gamma radiation. The RBE for 10 dicentrics per 100 cells was 3 for mixed beam and 7.2 for protons. For 20 dicentrics per 100 cells the respective values were 2.4 and 5.8. Within the limitations of the experimental setup the results indicate that for this endpoint there is no synergism between the high and low LET radiations.
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