799 research outputs found
Collaborative systems for enhancing the analysis of social surveys: the grid enabled specialist data environments
This paper describes a group of online services which are designed to support social
survey research and the production of statistical results. The 'Grid Enabled Specialist
Data Environment' (GESDE) services constitute three related systems which offer
facilities to search for, extract and exploit supplementary data and metadata concerned
with the measurement and operationalisation of survey variables. The services also offer
users the opportunity to deposit and distribute their own supplementary data resources for
the benefit of dissemination and replication of the details of their own analysis.
The GESDE services focus upon three application areas: specialist data relating to the
measurement of occupations; educational qualifications; and ethnicity (including
nationality, language, religion, national identity). They identify information resources
related to the operationalisation of variables which seek to measure each of these
concepts - examples include coding frames, crosswalk and translation files, and
standardisation and harmonisation recommendations. These resources constitute
important supplementary data which can be usefully exploited in the analysis of survey
data. The GESDE services work by collecting together as much of this supplementary
data as possible, and making it searchable and retrievable to others. This paper discusses
the current features of the GESDE services (which have been designed as part of a wider
programme of ‘e-Science’ research in the UK), and considers ongoing challenges in
providing effective support for variable-oriented statistical analysis in the social sciences
Oxygen isotopic ratios in cool R Coronae Borealis stars
We investigate the relationship between R Coronae Borealis (RCB) stars and
hydrogen-deficient carbon (HdC) stars by measuring precise 16O/18O ratios for
five cool RCB stars. The 16O/18O ratios are derived by spectrum synthesis from
high-resolution (R=50,000) K-band spectra. Lower limits to the 16O/17O and
14N/15}N ratios as well as Na and S abundances (when possible) are also given.
RCB stars in our sample generally display less 18O than HdC stars - the derived
16O/18O ratios range from 3 to 20. The only exception is the RCB star WX CrA,
which seems to be a HdC-like star with 16O/18O=0.3. Our result of a higher
16O/18O ratio for the RCB stars must be accounted for by a theory of the
formation and evolution of HdC and RCB stars. We speculate that a late
dredge-up of products of He-burning, principally 12C and 16O, may convert a
18O-rich HdC star into a 18O-poor RCB star as the H-deficient star begins its
final evolution from a cool supergiant to the top of the white dwarf cooling
track.Comment: Accepted for publication in the Astrophysical Journal; 21 pages, 3
Tables, 11 Figure
Calmodulin interacts with angiotensin-converting enzyme-2 (ACE2) and inhibits shedding of its ectodomain
AbstractAngiotensin-converting enzyme-2 (ACE2) is a regulatory protein of the renin–angiotensin system (RAS) and a receptor for the causative agent of severe-acute respiratory syndrome (SARS), the SARS-coronavirus. We have previously shown that ACE2 can be shed from the cell surface in response to phorbol esters by a process involving TNF-α converting enzyme (TACE; ADAM17). In this study, we demonstrate that inhibitors of calmodulin also stimulate shedding of the ACE2 ectodomain, a process at least partially mediated by a metalloproteinase. We also show that calmodulin associates with ACE2 and that this interaction is decreased by calmodulin inhibitors
Metadata Creation, Transformation and Discovery for Social Science Data Management: The DAMES Project Infrastructure
This paper discusses the use of metadata, underpinned by DDI (Data Documentation Initiative), to support social science data management. Social science data management refers broadly to the discovery, preparation, and manipulation of social science data for the purposes of research and analysis. Typical tasks include recoding variables within a dataset, and linking data from different sources. A description is given of the DAMES project (Data Management through e-Social Science), a UK project which is building resources and services to support quantitative social science data management activities. DAMES provides generic facilities for performing (and recording) operations on data. Specific resources include support for analysis through micro-simulation, and support for access to specialist data on occupations, educational qualifications, measures of ethnicity and immigration, social care, and mental health. The DAMES project tools and services can generate, use, transform, and search metadata that describe social science datasets (including microdata from social survey datasets and aggregate-level macrodata). On DAMES, these metadata are described by various standards including DDI Version 2, DDI Version 3, JSDL (Job Submission Definition Language), and the purpose-designed JFDL (Job Flow Definition Language). The paper describes how DAMES uses metadata with a range of resources that are integrated with a job execution infrastructure, a Web portal, and a tool for data fusion
Enabling quantitative data analysis through e-infrastructures
This paper discusses how quantitative data analysis in the social sciences can engage with and exploit an e-Infrastructure. We highlight how a number of activities which are central to quantitative data analysis, referred to as ‘data management’, can benefit from e-infrastructure support. We conclude by discussing how these issues are relevant to the DAMES (Data Management through e-Social Science) research Node, an ongoing project that aims to develop e-Infrastructural resources for quantitative data analysis in the social sciences
Redox-dependent Franck–Condon blockade and Avalanche Transport in a Graphene–Fullerene single-molecule transistor
We report transport measurements on a graphene–fullerene single-molecule transistor. The device architecture where a functionalized C60 binds to graphene nanoelectrodes results in strong electron–vibron coupling and weak vibron relaxation. Using a combined approach of transport spectroscopy, Raman spectroscopy, and DFT calculations, we demonstrate center-of-mass oscillations, redox-dependent Franck–Condon blockade, and a transport regime characterized by avalanche tunnelling in a single-molecule transistor
HD 11397 and HD 14282 - Two new barium stars?
We have performed a detailed abundance analysis of the content of s-process
elements of two dwarf stars with suspected overabundace of those elements. Such
stars belong to a special kinematic sample of the solar neighborhood, with
peculiar kinematics and different chemical abundances when compared to "normal"
disk stars. We aim to define if those stars can be identified as barium stars,
based on their s-process elements abundances, and their classification, i.e.,
if they share their chemical profile with strong or mild barium stars. We also
intend to shed light on the possible origins of the different kinds of barium
stars. Spectra have been taken by using the FEROS spectrograph at the 1.52m
telescope of ESO, La Silla. Abundances have been derived for 18 elements, by
matching the synthetic profile with the observed spectrum. We have found that
HD 11397 shows a mild enhancement for most of the s-process elements as well as
for some r-process elements. This star seems to share its abundance profile
with the mild Ba-stars. Although showing some slight chemical anomalies for Y,
Sr, Mo, and Pb, HD 14282 depicts a chemical pattern similar to the normal stars
with slight s-process enhancements.Comment: 11 pages, 5 figure
Scientific, Back-Illuminated CCD Development for the Transiting Exoplanet Survey Satellite
We describe the development of the fully depleted, back illuminated charge coupled devices for the Transiting Exoplanet Survey Satellite, which includes a set of four wide angle telescopes, each having a 2x2 array of CCDs. The devices are fabricated on the newly upgraded 200-mm wafer line at Lincoln Laboratory. We discuss methods used to produce the devices and present early performance results from the 100- micron thick, 15x15-microns, 2k x 4k pixel frame transfer CCDs
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