Neonatal CD8 T-cell Hierarchy Is Distinct from Adults and Is Influenced by Intrinsic T cell Properties in Respiratory Syncytial Virus Infected Mice

Following respiratory syncytial virus infection of adult CB6F1 hybrid mice, a predictable CD8+ T cell epitope hierarchy is established with a strongly dominant response to a Kd-restricted peptide (SYIGSINNI) from the M2 protein. The response to KdM282-90 is ∼5-fold higher than the response to a subdominant epitope from the M protein (NAITNAKII, DbM187-195). After infection of neonatal mice, a distinctly different epitope hierarchy emerges with codominant responses to KdM282-90 and DbM187-195. Adoptive transfer of naïve CD8+ T cells from adults into congenic neonates prior to infection indicates that intrinsic CD8+ T cell factors contribute to age-related differences in hierarchy. Epitope-specific precursor frequency differs between adults and neonates and influences, but does not predict the hierarchy following infection. Additionally, dominance of KdM282-90 –specific cells does not correlate with TdT activity. Epitope-specific Vβ repertoire usage is more restricted and functional avidity is lower in neonatal mice. The neonatal pattern of codominance changes after infection at 10 days of age, and rapidly shifts to the adult pattern of extreme KdM282- 90 -dominance. Thus, the functional properties of T cells are selectively modified by developmental factors in an epitope-specific and age-dependent manner

The rank reversal problem in multi-criteria decision making : a literature review

Despite the importance of multicriteria decision-making (MCDM) techniques for constructing effective decision models, there are many criticisms due to the occurrence of a problem called rank reversal. Nevertheless, there is a lack of a systematic literature review on this important subject which involves different methods. This study reviews the pertinent literature on rank reversal, based on 130 related articles published from 1980 to 2015 in international journals, which were gathered and analyzed according to the following perspectives: multicriteria technique, year and journal in which the papers were published, co-authorship network, rank reversal types, and research goal. Thus our survey provides recommendations for future research, besides useful information and knowledge regarding rank reversal in the MCDM field

The effects of metal surface geometry on the formation of uranium hydride

The present work examines the effect of surface geometry on the reaction between hydrogen gas and uranium metal, forming uranium hydride (UH3), a pyrophoric compound of significance to the civil nuclear industry. Hydride formation was initiated on uranium samples that had been patterned with a focused ion beam instrument to form surface arrays of triangular prisms and pillars with differing apex angles. Post reaction analysis indicated preferential hydride formation at the apex of these features. Additionally, once hydride formation had commenced the observed growth rate on the prisms appeared to accelerate in comparison to the rate exhibited on the surrounding surface

Real time, in-situ deuteriding of uranium encapsulated in grout; effects of temperature on the uranium-deuterium reaction

To accurately predict the initiation and evolution of uranium hydride potentially present in nuclear waste containers, studies of simulated conditions are required. Here, for the first time, the uranium-deuterium reaction was examined in-situ, in real time, whilst within grouted media. A deuterium gas control rig and stainless steel-quartz glass reaction cell were configured on a synchrotron beam line to collect X-ray diffraction and X-ray tomography data. It was found that deuteride formation was limited by the uranium and grout thermal conductivities and deuteride initiation only commenced above a threshold temperature. Strong adherence between uranium oxide and grout was also observed

Modified Abrasion pH and NAGpH testing of minerals

Synchrotron X-rays have been used to study the oxidation of uranium and uranium hydride when encapsulated in grout and stored in de-ionised water for 10 months. Periodic synchrotron X-ray tomography and X-ray powder diffraction have allowed measurement and identification of the arising corrosion products and the rates of corrosion. The oxidation rates of the uranium metal and uranium hydride were slower than empirically derived rates previously reported for each reactant in an anoxic water system, but without encapsulation in grout. This was attributed to the grout acting as a physical barrier limiting the access of oxidising species to the uranium surface. Uranium hydride was observed to persist throughout the 10 month storage period and industrial consequences of this observed persistence are discussed