Large amplitude change in spot-induced rotational modulation of the Kepler Ap star KIC 2569073

An investigation of the 200 × 200 pixel 'superstamp' images of the centres of the open clusters NGC 6791 and NGC 6819 allows for the identification and study of many variable stars that were not included in the Kepler target list. KIC 2569073 (V=14.22), is a particularly interesting variable Ap star that we discovered in the NGC 6791 superstamp. With a rotational period of 14.67 days and 0.034-mag variability, it has one of the largest peak-to-peak variations of any known Ap star. Colour photometry reveals an anti-phase correlation between the B band, and the V, R and I bands. This Ap star is a rotational variable, also known as an α2 CVn, star, and is one of only a handful of Ap stars observed by Kepler. While no change in spot period or amplitude is observed within the 4-year Kepler timeseries, the amplitude shows a large increase compared to ground-based photometry obtained two decades ago

IAEA activities on cultural heritage, archaeology and other characterization applications

Trace element determination is crucial for identifying the provenance and authenticity of intact ancient objects such as cultural and art artefacts, archaeological findings and forensic materials, geological objects, etc. A non-destructive technique suitable for analysis of trace elements in bulk-samples is highly needed. The IAEA initiated a series of coordinated research projects (CRP) to support Member States on their R&D programs. Large Sample Neutron Activation Analysis (LSNAA) is a very attractive non-destructive technique that can be applied without a need for sub-sampling and homogenization. LSNAA can be operated in ‘on-line’ mode which is based on the use of isotopic neutron sources, neutron generators and prompt gamma analysis. An on-going CRP focuses primarily on the application of LSNAA in the area of archaeological and geological programmes. However, further utilization of LSNAA in other subjects of industry and research is promising. Large scale campaigns of archaeological excavations are undertaken in the Mediterranean region. The IAEA is supporting Technical Cooperation projects in the Middle East in view of studying authenticity and origin of objects of art and archaeology, as well as to characterize new elaborated materials or environmental samples, making use of Ion Beam Accelerators (IBA) as nuclear analytical tool and other nuclear analytical techniques. The application of nuclear analytical tools in archaeology is of special concern as many common ancient civilizations are shared by the Mediterranean state. The main IBA techniques to be used are: PIXE, PIGE and RBS, as well as XRF. To take advantage of these nuclear techniques, many researchers from the participating countries have initiated several studies and exchange of experience, knowledge, results and expertise is on-going

Mitigation strategies for radiation damage in the analysis of ancient materials

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Practical advances towards safer analysis of heritage samples and objects

International audienceIn recent years, we have seen a significant increase in interest in the effects of irradiation used for analytical purposes on art, archaeological, palaeontological and palaeoenvironmental samples and objects. Among the main trends regarding ionising radiations used in X-ray, UV and ion beam experiments, we have observed a greater consistency in the description of the effects of irradiation, a number of quantitative studies, while several works studied in depth the corresponding chemical mechanisms and kinetics. We have also observed the development of analytical strategies and dedicated instruments to better detect and limit the effects of irradiation in real experiments on ancient samples and objects. Emerging trends include detailed mechanistic studies on specific systems, the development of statistical methods to reduce the doses required to study samples, and the development of early warning systems capable of feeding back into the experiment while an acquisition is in progress

Variability of M giant stars based on Kepler photometry: general characteristics

M giants are among the longest period pulsating stars which is why their studies were traditionally restricted to analyses of low-precision visual observations, and, more recently, accurate ground-based data. Here we present an overview of M giant variability on a wide range of time-scales (hours to years), based on the analysis of 13 quarters of Kepler long-cadence observations (one point per every 29.4 min), with a total time-span of over 1000 d. About two-thirds of the sample stars have been selected from the All Sky Automated Survey (ASAS)-North survey of the Kepler field, with the rest supplemented from a randomly chosen M giant control sample. We first describe the correction of the light curves from different quarters, which was found to be essential. We use Fourier analysis to calculate multiple frequencies for all stars in the sample. Over 50 stars show a relatively strong signal with a period equal to the Kepler-year and a characteristic phase dependence across the whole field of view. We interpret this as a so far unidentified systematic effect in the Kepler data. We discuss the presence of regular patterns in the distribution of multiple periodicities and amplitudes. In the period-amplitude plane we find that it is possible to distinguish between solar-like oscillations and larger amplitude pulsations which are characteristic for Mira/semiregular stars. This may indicate the region of the transition between two types of oscillations as we move upward along the giant branch

Reduced Cancer Incidence in Huntington's Disease: Analysis in the Registry Study

Background: People with Huntington's disease (HD) have been observed to have lower rates of cancers. Objective: To investigate the relationship between age of onset of HD, CAG repeat length, and cancer diagnosis. Methods: Data were obtained from the European Huntington's disease network REGISTRY study for 6540 subjects. Population cancer incidence was ascertained from the GLOBOCAN database to obtain standardised incidence ratios of cancers in the REGISTRY subjects. Results: 173/6528 HD REGISTRY subjects had had a cancer diagnosis. The age-standardised incidence rate of all cancers in the REGISTRY HD population was 0.26 (CI 0.22-0.30). Individual cancers showed a lower age-standardised incidence rate compared with the control population with prostate and colorectal cancers showing the lowest rates. There was no effect of CAG length on the likelihood of cancer, but a cancer diagnosis within the last year was associated with a greatly increased rate of HD onset (Hazard Ratio 18.94, p < 0.001). Conclusions: Cancer is less common than expected in the HD population, confirming previous reports. However, this does not appear to be related to CAG length in HTT. A recent diagnosis of cancer increases the risk of HD onset at any age, likely due to increased investigation following a cancer diagnosis