Performance data of US Naval Observatory VLG-11 hydrogen masers since September, 1983

In 1983, two VLC-11 masers were delivered to the U.S. Naval Observatory by the Smithsonian Astrophysical Observatory. Last year the short-term stability of these masers was reported and the effect of this short-term stability on timekeeping performance was examined. Since the date of installation, 13 September 1983, data on the masers' long-term performance have been accumulated. The Allan variance, agma(tau), of the relative frequency between the masers reaches a minimum of about 4 parts in 10 to the 16th power at averaging times 5,000 seconds and rises at longer averaging times due, at least partly, to systematic frequency drift. The systematic frequency drifts, expressed in units of fractional frequency difference per day are discussed

Brown tumor mimicking metastases-the late manifestation of hyperparathyroidism

Brown tumors are uncommon manifestations of hyperparathyroidism (HPT) that without awareness are easily misdiagnosed as metastases. This short report highlights the importance of clinical context and clear communication between medical specialties when interpreting complex radiologic findings

Forecast, observation and modelling of a deep stratospheric intrusion event over Europe

A wide range of measurements was carried out in central and southeastern Europe within the framework of the EU-project STACCATO (Influence of Stratosphere-Troposphere Exchange in a Changing Climate on Atmospheric Transport and Oxidation Capacity) with the principle goal to create a comprehensive data set on stratospheric air intrusions into the troposphere along a rather frequently observed pathway over central Europe from the North Sea to the Mediterranean Sea. The measurements were based on predictions by suitable quasi-operational trajectory calculations using ECMWF forecast data. A predicted deep Stratosphere to Troposphere Transport (STT) event, encountered during the STACCATO period on 20-21 June 2001, could be followed by the measurements network almost from its inception. Observations provide evidence that the intrusion affected large parts of central and southeastern Europe. Especially, the ozone lidar observations on 20-21 June 2001 at Garmisch-Partenkirchen, Germany captured the evolution of two marked tongues of high ozone with the first one reaching almost a height of 2 km, thus providing an excellent data set for model intercomparisons and validation. In addition, for the first time to our knowledge concurrent measurements of the cosmogenic radionuclides <sup>10</sup>Be and <sup>7</sup>Be and their ratio <sup>10</sup>Be/<sup>7</sup>Be are presented together as stratospheric tracers in a case study of a stratospheric intrusion. The ozone tracer columns calculated with the FLEXPART model were found to be in good agreement with water vapour satellite images, capturing the evolution of the observed dry streamers of stratospheric origin. Furthermore, the time-height cross section of ozone tracer simulated with FLEXPART over Garmisch-Partenkirchen captures with many details the evolution of the two observed high-ozone filaments measured with the IFU lidar, thus demonstrating the considerable progress in model simulations. Finally, the modelled ozone (operationally available since October 1999) from the ECMWF (European Centre for Medium-Range Weather Forecasts) atmospheric model is shown to be in very good agreement with the observations during this case study, which provides the first successful validation of a chemical tracer that is used operationally in a weather forecast model. This suggests that coupling chemistry and weather forecast models may significantly improve both weather and chemical forecasts in the future

FEM Analysis of Clinching Tool Load in a Joint of Dual-Phase Steels

The clinching tool with a die of 5 mm diameter with a specially formed gap and a punch of 3.6 mm diameter were used for mechanical joining of dual-phase steel sheets DP600 with the pressing force of 30 kN. The punch and die were deposited by PVD coating of CrN type with LARC technology. The coating state of each 50th manufactured join was evaluated by SEM. Cracks in the area of punch’s radius were detected. The finite element method was applied for the assessment of punch load in the joining process

Time decay of the remanent magnetization in the ±J\pm J spin glass model at T=0

Using the zero-temperature Metropolis dynamics, the time decay of the remanent magnetization in the $\pm J$ Edward-Anderson spin glass model with a uniform random distribution of ferromagnetic and antiferromagnetic interactions has been investigated. Starting from the saturation, the magnetization per spin $m$ reveals a slow decrease with time, which can be approximated by a power law:$m(t)=m_{\infty}+ ({t\over a_{0}})^{a_{1}}$, $a_{1} < 0$. Moreover, its relaxation does not lead it into one of the ground states, and therefore the system is trapped in metastable isoenergetic microstates remaining magnetized. Such behaviour is discussed in terms of a random walk the system performs on its available configuration space.Comment: 9 pages, 3 figure

16th IHIW: Immunogenetics of Aging

Ageing is a process characterised by progressive loss of function in multiple different organ systems, such as the nervous, endocrine and immune systems. Current data showing that ageing processes may be associated with alterations in the immune system suggest that some of the genetic determinants of senescence might be polymorphic genes that regulate immune responses. The ‘Immunogenetics of Aging’ programme was a component introduced in the 14th International HLA and Immunogenetics Workshop (IHIWS) and developed further within the 15th and 16th. The aim of this component was to determine the contribution of immune genes to successful ageing and an increased capacity to reach the extreme limits of lifespan. Within the 16th IHIWS, new populations were included, and the number of samples analysed was increased. Analysis was focused on innate immunity genes (KIR and MBL2) and their correlation with CMV serostatus. Collaborative studies suggested that both activating and inhibitory KIR and functionally relevant MBL2 haplotypes are important factors for control of CMV infection in the elderly and therefore for chronic low-grade inflammation. Results showed that these genes might be predictive biomarkers in ageing and longevity. Prevalence of MBL2 haplotypes determining absence of the protein (LYPB, LYQC and HYPD) was observed in elderly people with a higher CMV antibody titre. The high CMV titre was also associated with a decreased frequency of the activatory KIR2DS5 and A1B10 haplotypes in elderly. Due to the role of KIR and low or deficient MBL haplotypes in viral infections, these genetic markers could be considered as indicators of a need for CMV prophylaxis at younger age and therefore increased probability of longer lifespan