69 research outputs found
A high resolution search for the tensor glueball candidate [xi] (2230) Crystal Barrel Collaboration
We report results of a high resolution search for the tensor glueball candidate ξ(2230) in a p̄p formation experiment. π0π0 and ηη decay channels were measured in a scan of the mass region 2220 MeV to 2240 MeV. No evidence for the existence of ξ(2230) was found. 95% confidence upper limits for the possible existence of ξ are presented
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'The debatable territory where geology and archaeology meet': reassessing the early archaeobotanical work of Clement Reid and Arthur Lyell at Roman Silchester
The first large-scale archaeobotanical study in Britain, conducted from 1899 to 1909 by Clement Reid and
Arthur Lyell at Silchester, provided the first evidence for the introduction of Roman plant foods to Britain,
yet the findings have thus far remained unverified. This paper presents a reassessment of these
archaeobotanical remains, now stored as part of the Silchester Collection in Reading Museum. The
documentary evidence for the Silchester study is summarised, before the results are presented for over a
1000 plant remains including an assessment of preservation, identification and modern contamination.
The dataset includes both evidence for the presence of nationally rare plant foods, such as medlar, and
several archaeophytes. The methodologies and original interpretations of Reid and Lyell’s study are
reassessed in light of current archaeobotanical knowledge. Spatial and contextual patterns in the
distribution of plant foods and ornamental taxa are also explored. Finally, the legacy of the study for the
development of archaeobotany in the 20th century is evaluated
Apoptotic surge of potassium currents is mediated by p38 phosphorylation of Kv2.1
Kv2.1, the primary delayed rectifying potassium channel in neurons, is extensively regulated by phosphorylation. Previous reports have described Kv2.1 phosphorylation events affecting channel gating and the impact of this process on cellular excitability. Kv2.1, however, also provides the critical exit route for potassium ions during neuronal apoptosis via p38 MAPK-dependent membrane insertion, resulting in a pronounced enhancement of K(+) currents. Here, electrophysiological and viability studies using Kv2.1 channel mutants identify a p38 phosphorylation site at Ser-800 (S800) that is required for Kv2.1 membrane insertion, K(+) current surge, and cell death. In addition, a phospho-specific antibody for S800 detects a p38-dependent increase in Kv2.1 phosphorylation in apoptotic neurons and reveals phosphorylation of S800 in immunopurified channels incubated with active p38. Consequently, phosphorylation of Kv2.1 residue S800 by p38 leads to trafficking and membrane insertion during apoptosis, and remarkably, the absence of S800 phosphorylation is sufficient to prevent completion of the cell death program
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