SAMP, the Simple Application Messaging Protocol: Letting applications talk to each other

SAMP, the Simple Application Messaging Protocol, is a hub-based communication standard for the exchange of data and control between participating client applications. It has been developed within the context of the Virtual Observatory with the aim of enabling specialised data analysis tools to cooperate as a loosely integrated suite, and is now in use by many and varied desktop and web-based applications dealing with astronomical data. This paper reviews the requirements and design principles that led to SAMP's specification, provides a high-level description of the protocol, and discusses some of its common and possible future usage patterns, with particular attention to those factors that have aided its success in practice.Comment: 12 pages, 3 figures. Accepted for Virtual Observatory special issue of Astronomy and Computin

IVOA Recommendation: SAMP - Simple Application Messaging Protocol Version 1.3

SAMP is a messaging protocol that enables astronomy software tools to interoperate and communicate. IVOA members have recognised that building a monolithic tool that attempts to fulfil all the requirements of all users is impractical, and it is a better use of our limited resources to enable individual tools to work together better. One element of this is defining common file formats for the exchange of data between different applications. Another important component is a messaging system that enables the applications to share data and take advantage of each other's functionality. SAMP builds on the success of a prior messaging protocol, PLASTIC, which has been in use since 2006 in over a dozen astronomy applications and has proven popular with users and developers. It is also intended to form a framework for more general messaging requirements

Hierarchical progressive surveys. Multi-resolution HEALPix data structures for astronomical images, catalogues, and 3-dimensional data cubes

Scientific exploitation of the ever increasing volumes of astronomical data requires efficient and practical methods for data access, visualisation, and analysis. Hierarchical sky tessellation techniques enable a multi-resolution approach to organising data on angular scales from the full sky down to the individual image pixels. Aims. We aim to show that the Hierarchical progressive survey (HiPS) scheme for describing astronomical images, source catalogues, and three-dimensional data cubes is a practical solution to managing large volumes of heterogeneous data and that it enables a new level of scientific interoperability across large collections of data of these different data types. Methods. HiPS uses the HEALPix tessellation of the sphere to define a hierarchical tile and pixel structure to describe and organise astronomical data. HiPS is designed to conserve the scientific properties of the data alongside both visualisation considerations and emphasis on the ease of implementation. We describe the development of HiPS to manage a large number of diverse image surveys, as well as the extension of hierarchical image systems to cube and catalogue data. We demonstrate the interoperability of HiPS and Multi-Order Coverage (MOC) maps and highlight the HiPS mechanism to provide links to the original data. Results. Hierarchical progressive surveys have been generated by various data centres and groups for ~200 data collections including many wide area sky surveys, and archives of pointed observations. These can be accessed and visualised in Aladin, Aladin Lite, and other applications. HiPS provides a basis for further innovations in the use of hierarchical data structures to facilitate the description and statistical analysis of large astronomical data sets.Comment: 21 pages, 6 figures. Accepted for publication in Astronomy & Astrophysic

Early psychosocial intervention in Alzheimer’s disease:Cost utility evaluation alongside the Danish Alzheimer’s Intervention Study (DAISY)

OBJECTIVE: To assess the cost utility of early psychosocial intervention for patients with Alzheimer's disease and their primary caregivers. DESIGN: Cost utility evaluation alongside a multicentre, randomised controlled trial with 3 years of follow-up. SETTING: Primary care and memory clinics in five Danish districts. PARTICIPANTS: 330 community-dwelling patients and their primary caregivers. INTERVENTION: Psychosocial counselling and support lasting 8–12 months after diagnosis and follow-up at 3, 6, 12 and 36 months in the intervention group or follow-up only in the control group. MAIN OUTCOME MEASURES: The primary outcome measure was the cost of additional quality-adjusted life years (QALYs). Costs were measured from a societal perspective, including the costs of healthcare, social care, informal care and production loss. QALYs were estimated separately for the patient and the caregiver before aggregation for the main analysis. RESULTS: None of the observed cost and QALY measures were significantly different between the intervention and control groups, although a tendency was noted for psychosocial care leading to cost increases with informal care that was not outweighed by the tendency for cost savings with formal care. The probability of psychosocial intervention being cost-effective did not exceed 36% for any threshold value. The alternative scenario analysis showed that the probability of cost-effectiveness increased over the range of threshold values used if the cost perspective was restricted to formal healthcare. CONCLUSIONS: A multifaceted, psychosocial intervention programme was found unlikely to be cost-effective from a societal perspective. The recommendation for practice in settings that are similar to the Danish setting is to provide follow-up with referral to available local support programmes when needed, and to restrict large multifaceted intervention programmes to patients and caregivers with special needs until further evidence for cost-effectiveness emerges. TRIAL REGISTRATION: The study was registered in the Clinical Trial Database as ISRCTN74848736

On the origin of the A1g_{1g} and B1g_{1g} electronic Raman scattering peaks in the superconducting state of YBa2_{2}Cu3_{3}O7−δ_{7-\delta}

The electronic Raman scattering has been investigated in optimally oxygen doped YBa$_{2}$Cu$_{3}$O$_{7-\delta}$ single crystals as well as in crystals with non-magnetic, Zn, and magnetic, Ni, impurities. We found that the intensity of the A$_{1g}$ peak is impurity independent and their energy to $T_{c}$ ratio is almost constant ($2\Delta/k_{B}T_{c}\sim5$). Moreover, the signal at the B$_{1g}$ channel is completely smeared out when non-magnetic Zn impurities are present. These results are qualitatively interpreted in terms of the Zeyher and Greco's theory that relates the electronic Raman scattering in the A$_{1g}$ and B$_{1g}$ channels to \textit{d}-CDW and superconducting order parameters fluctuations, respectively.Comment: Submited to Phys. Rev. Let

Honey bee foraging distance depends on month and forage type

To investigate the distances at which honey bee foragers collect nectar and pollen, we analysed 5,484 decoded waggle dances made to natural forage sites to determine monthly foraging distance for each forage type. Firstly, we found significantly fewer overall dances made for pollen (16.8 %) than for non-pollen, presumably nectar (83.2 %; P < 2.2 × 10−23). When we analysed distance against month and forage type, there was a significant interaction between the two factors, which demonstrates that in some months, one forage type is collected at farther distances, but this would reverse in other months. Overall, these data suggest that distance, as a proxy for forage availability, is not significantly and consistently driven by need for one type of forage over the other