Naresuan University Journal
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Bilateral vestibular schwannomas in older patients: NF2 or chance?
No full textBACKGROUND: Neurofibromatosis type 2 (NF2) is an autosomal dominant condition with high spontaneous mutation rate which predisposes to the development of multiple nerve sheath tumours (schwannomas), meningiomas and ependymoma. The cardinal feature and main diagnostic criterion for the diagnosis of NF2 remains the development of bilateral vestibular schwannoma (BVS). With increasing use of MRI screening the possibility of a 'chance' diagnosis of BVS has been mooted with a potential frequency of one in two million people in their lifetime. Until now, however, no evidence for such an event has been published. We aimed to demonstrate that chance occurrence can occur and to estimate its frequency among those with just BVS late in life. METHODS: Two vestibular schwannomas from the same patient were DNA sequenced and underwent loss of heterozygosity analysis. RESULTS: We show that a man who developed BVS, at ages 52 and 67 years developed these tumours sporadically by demonstrating that there were no molecular events in common between the two tumours. Furthermore from a database of over 1200 patients with NF2, we have estimated that ∼25% of cases of BVS over 50 years and 50% over 70 years of age where no other features of NF2 are present represent a chance occurrence rather than due to an underlying mosaic or constitutional NF2 mutation. CONCLUSIONS: Patients presenting with BVS later in life should be appraised of the potential likelihood they may not have NF2 and the resultant further reduction in risks of transmission to offspring
Search for low-scale gravity signatures in multi-jet final states with the ATLAS detector at TeV
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LOFAR MSSS: Detection of a low-frequency radio transient in 400 hrs of monitoring of the North Celestial Pole
No full textWe present the results of a four-month campaign searching for low-frequency radio transients near the North Celestial Pole with the Low-Frequency Array (LOFAR), as part of the Multifrequency Snapshot Sky Survey (MSSS). The data were recorded between 2011 December and 2012 April and comprised 2149 11-minute snapshots, each covering 175 deg^2. We have found one convincing candidate astrophysical transient, with a duration of a few minutes and a flux density at 60 MHz of 15-25 Jy. The transient does not repeat and has no obvious optical or high-energy counterpart, as a result of which its nature is unclear. The detection of this event implies a transient rate at 60 MHz of 3.9 (+14.7, -3.7) x 10^-4 day^-1 deg^-2, and a transient surface density of 1.5 x 10^-5 deg^-2, at a 7.9-Jy limiting flux density and 10-minute time-scale. The campaign data were also searched for transients at a range of other time-scales, from 0.5 to 297 min, which allowed us to place a range of limits on transient rates at 60 MHz as a function of observation duration
In-source laser spectroscopy with the Laser Ion Source and Trap: first direct study of the ground-state properties of 217,219Po
No full textA Laser Ion Source and Trap (LIST) for a thick-target, isotope-separation on-line facility has been implemented at CERN ISOLDE for the production of pure, laser-ionized, radioactive ion beams. It offers two modes of operation, either as an ion guide, which performs similarly to the standard ISOLDE resonance ionization laser ion source (RILIS), or as a more selective ion source, where surface-ionized ions from the hot ion-source cavity are repelled by an electrode, while laser ionization is done within a radiofrequency quadrupole ion guide. The first physics application of the LIST enables the suppression of francium contamination in ion beams of neutron-rich polonium isotopes at ISOLDE by more than 1000 with a reduction in laser-ionization efficiency of only 20. Resonance ionization spectroscopy is performed directly inside the LIST device, allowing the study of the hyperfine structure and isotope shift of 217Po for the first time. Nuclear decay spectroscopy of 219Po is performed for the first time, revealing its half-life, α- to-β-decay branching ratio, and α-particle energy. This experiment demonstrates the applicability of the LIST at radioactive ion-beam facilities for the production and study of pure beams of exotic isotopes
Project Organizing as a Problem in Information
No full textOne of the most influential perspectives in business and management has been the Carnegie School, represented by such luminaries as James March, Hebert Simon, Oliver Williamson and Zur Shapira. The perspective underpins much of contemporary organization theory and organizational economics. Yet there have only been limited attempts to apply it to the domain of construction economics and management. An important exception to this statement is the application of Williamson’s transaction cost economics to the governance of inter-firm relations in construction, but the opportunity is presently being missed for a more thorough-going application. The aim, therefore, is to suggest what such an application might look like and why it might be useful in stimulating new lines of research enquiry. The principal tenets of the Carnegie School are examined, as well as the central role of uncertainty and bounded rationality in those tenets. The contributions to organization theory of the Carnegie School are drawn upon to conceptualize project organizing as a problem in information, and suggest a new perspective on the microfoundations for that theory
Online adaptive optimal control for continuous-time Markov jump linear systems using a novel policy iteration algorithm
No full textThis study studies the online adaptive optimal control problems for a class of continuous-time Markov jump linear systems (MJLSs) based on a novel policy iteration algorithm. By utilising a new decoupling technique named subsystems transformation, the authors re-construct the MJLSs and a set of new coupled systems composed of N subsystems are obtained. The online policy iteration algorithm was used to solve the coupled algebraic matrix Riccati equations with partial knowledge regarding to the system dynamics, and the relevant optimal controllers equivalent to the investigated MJLSs are designed. Moreover, the convergence of the novel policy iteration algorithm is also established. Finally, a simulation example is given to illustrate the effectiveness and applicability of the proposed approach
Regulation of Ca(2+) transient by PP2A in normal and failing heart.
No full textCalcium transient in cardiomyocytes is regulated by multiple protein kinases and phosphatases. PP2A is a major protein phosphatase in the heart modulating Ca(2+) handling through an array of ion channels, antiporters and pumps, etc. The assembly, localization/translocation, and substrate specificity of PP2A are controlled by different post-translational mechanisms, which in turn are linked to the activities of upstream signaling molecules. Abnormal PP2A expression and activities are associated with defective response to β-adrenergic stimulation and are indication and causal factors in arrhythmia and heart failure
Collecting urban health indicators from routinely available sources: development and piloting of a tool for the collection of existing data for EURO-URHIS 2.
No full textINTRODUCTION: EURO-URHIS 2 aimed to collect comparable health indicators across a large number of urban areas (UAs) across Europe and Vietnam using four data collection tools. This paper outlines the process for the selection of indicators to be collected from routinely available sources, and the piloting of the data collection tool. METHODS: A long-list of indicators potentially collectable from routinely available sources was generated by the EURO-URHIS 2 consortium. Key contacts from each UA completed an e-mail survey reporting for each indicator whether it could be collected using the given definition, an alternative definition or not at all. Additionally participants listed the 20 leading causes of death for their UAs from the Eurostat 65. Results were compiled to inform indicator selection for the main data collection phase. RESULTS: Responses were received for 25 of 28 eligible UAs. Of the 29 proposed indicators, 55.1% (n = 16) were accepted without change, 24.1% (n = 7) were re-allocated to other data collection tools and 17.2% (n = 5) were accepted after a modification of the EURO-URHIS 2 definition. DISCUSSION: This scoping exercise and piloting phase for the 'existing data tool' for the project was useful and informative. It provided detailed information on what could be collected, and an opportunity to modify indicator definitions to maximize response rates. These results are only applicable to those UAs returning results and cannot be generalized. Detailed interrogation of definitions is essential to this sort of data collection, and the process described was designed with cross-national comparability in mind