3,187 research outputs found
Blogging: an opportunity for librarians to communicate, participate and collaborate on a global scale
Blogs are an important element of the second generation of the web; or âWeb 2.0â as it is commonly referred to. âWeb 2.0â refers to the evolution from static "read only" web pages (Web 1.0) to dynamic, interactive pages encouraging users to create, interact and share content across multiple applications (OâReilly, 2005). Blogging, along with other Web 2.0 technologies such as social networking, wikis, social bookmarking, photo sharing, video sharing, and microblogging, form part of the emergent âsocial mediaâ family; a collection of online tools that encourage users to communicate, participate, and collaborate on a global scale. Many library and information professionals have embraced blogging as a platform to document their career, enhance their profile, network with other librarians; and share anecdotes about their lives as librarians. The aim of this article is to present a brief overview of the history of blogs and a short review of literature related to blogging, libraries and reference librarians. It will also provide a list of recommended blogs, a discussion of the advantages of reading and writing blogs and some top tips for starting up your own blog
The Sagittarius dwarf galaxy as a microlensing target
We estimate the optical depth, time-scale distribution and fraction of
microlensing events originating from sources in the Sagittarius dwarf galaxy
(Sgr) lensed by deflectors in the Milky Way. These events have a time-scale
longer by a factor ~1.3 than the MW/MW events and occur mainly on sources
fainter than V~21 mag below Sgr's turn off. The fraction of events involving a
source in Sgr depends on the location and extinction of the field and on the
limiting magnitude of the survey. The contribution of the MW/Sgr events is
negligible (<1%) at very low latitudes (|b|<2 deg.) but increases continuously
towards higher |b| and becomes dominant near the highest density region of the
dwarf galaxy. Sgr is present within the fields of current microlensing surveys
and any optical depth map inferred from observations will become biased by the
presence of Sgr towards higher |b| where the contribution of MW/Sgr events is
significant. Systematic spectroscopic measurements on the sources of all the
microlensing events may allow detection of this kind of event for which the
degeneracy on the lens mass can be significantly reduced.Comment: 9 pages, 8 figures. Accepted for publication in A&A Main Journa
Early production of the passive in two Eastern Bantu languages
The passive construction is acquired relatively late by children learning to speak many languages, with verbal passives not fully acquired till age 6 in English. In other languages it appears earlier, around age 3 or before. Use of passive construction in young children was examined in two Eastern Bantu languages spoken in Kenya (Kiswahili and Kigiriama), both with frequent use of passive. The passive was used productively very early (2;1) in these languages, regardless of the method used to measure productivity. In addition non-actional passives, particularly rare in English and some other European languages, were seen at these early ages. The proportion of verbs that were passive varied between individuals, both in children's speech and in the input to children. Pragmatic and grammatical features of the passive in some languages have previously been suggested to drive early passive acquisition, but these features are not found consistently in the two languages studied here. Findings suggest that the relatively high frequency of input found in these languages is the most plausible reason for early productive use of the passive
X-ray Pulsations in the Supersoft X-ray Binary CAL 83
X-ray data reveal that the supersoft X-ray binary CAL 83 exhibits 38.4 minute
pulsations at some epochs. These X-ray variations are similar to those found in
some novae and are likely to be caused by nonradial pulsations the white dwarf.
This is the first detection of pulsations in a classical supersoft X-ray
binary.Comment: revised text; 11 pages and 3 figures; accepted for publication in the
Astronomical Journa
High-energy Astrophysics and the Virtual Observatory
The Virtual Observatory (VO) will revolutionise the way we do Astronomy by
allowing easy access to all astronomical data and by making the handling and
analysis of datasets at various locations across the globe much simpler and
faster. I report here on the need for the VO and its status in Europe,
concentrating on the recently started EURO-VO project, and then give two
specific applications of VO tools to high-energy astrophysics.Comment: 12 pages, 3 figures, invited talk at the Workshop ``Multifrequency
Behaviour of High Energy Cosmic Sources'', Vulcano, Italy, May 2005, F.
Giovannelli et al., in pres
A compact high-flux source of cold sodium atoms
We present a compact source of cold sodium atoms suitable for the production
of quantum degenerate gases and versatile for a multi-species experiment. The
magnetic field produced by permanent magnets allows to simultaneously realize a
Zeeman slower and a two-dimensional MOT within an order of magnitude smaller
length than standard sodium sources. We achieve an atomic flux exceeding 4x10^9
atoms/s loaded in a MOT, with a most probable longitudinal velocity of 20 m/s,
and a brightness larger than 2.5x10^(12) atoms/s/sr. This atomic source allowed
us to produce a pure BEC with more than 10^7 atoms and a background pressure
limited lifetime of 5 minutes.Comment: 8 pages, 6 figures, submitted to Phys. Rev.
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