24 research outputs found
E-prints and Journal Articles in Astronomy: a Productive Co-existence
Are the e-prints (electronic preprints) from the arXiv repository being used
instead of the journal articles? In this paper we show that the e-prints have
not undermined the usage of journal papers in the astrophysics community. As
soon as the journal article is published, the astronomical community prefers to
read the journal article and the use of e-prints through the NASA Astrophysics
Data System drops to zero. This suggests that the majority of astronomers have
access to institutional subscriptions and that they choose to read the journal
article when given the choice. Within the NASA Astrophysics Data System they
are given this choice, because the e-print and the journal article are treated
equally, since both are just one click away. In other words, the e-prints have
not undermined journal use in the astrophysics community and thus currently do
not pose a financial threat to the publishers. We present readership data for
the arXiv category "astro-ph" and the 4 core journals in astronomy
(Astrophysical Journal, Astronomical Journal, Monthly Notices of the Royal
Astronomical Society and Astronomy & Astrophysics). Furthermore, we show that
the half-life (the point where the use of an article drops to half the use of a
newly published article) for an e-print is shorter than for a journal paper.
The ADS is funded by NASA Grant NNG06GG68G. arXiv receives funding from NSF
award #0404553Comment: 8 pages, 4 figures, submitted to Learned Publishin
The Effect of Use and Access on Citations
It has been shown (S. Lawrence, 2001, Nature, 411, 521) that journal articles
which have been posted without charge on the internet are more heavily cited
than those which have not been. Using data from the NASA Astrophysics Data
System (ads.harvard.edu) and from the ArXiv e-print archive at Cornell
University (arXiv.org) we examine the causes of this effect.Comment: Accepted for publication in Information Processing & Management,
special issue on scientometric
No evidence of the Shiga toxin-producing E. coli O104:H4 outbreak strain or enteroaggregative E. coli (EAEC) found in cattle faeces in northern Germany, the hotspot of the 2011 HUS outbreak area
<p>Abstract</p> <p>Background</p> <p>Ruminants, in particular bovines, are the primary reservoir of Shiga toxin-producing <it>E. coli </it>(STEC), but whole genome analyses of the current German ESBL-producing O104:H4 outbreak strain of sequence type (ST) 678 showed this strain to be highly similar to enteroaggregative <it>E. coli </it>(EAEC). Strains of the EAEC pathotype are basically adapted to the human host. To clarify whether in contrast to this paradigm, the O104:H4 outbreak strain and/or EAEC may also be able to colonize ruminants, we screened a total of 2.000 colonies from faecal samples of 100 cattle from 34 different farms - all located in the HUS outbreak region of Northern Germany - for genes associated with the O104:H4 HUS outbreak strain (<it>stx2</it>, <it>terD</it>, <it>rfb</it><sub>O104</sub>, <it>fliC</it><sub>H4</sub>), STEC (<it>stx1</it>, <it>stx2</it>, <it>escV</it>), EAEC (<it>pAA</it>, <it>aggR, astA</it>), and ESBL-production (<it>bla</it><sub>CTX-M</sub>, <it>bla</it><sub>TEM</sub>, <it>bla</it><sub>SHV</sub>).</p> <p>Results</p> <p>The faecal samples contained neither the HUS outbreak strain nor any EAEC. As the current outbreak strain belongs to ST678 and displays an en-teroaggregative and ESBL-producing phenotype, we additionally screened selected strains for ST678 as well as the aggregative adhesion pattern in HEp-2 cells. However, we were unable to find any strains belonging to ST678 or showing an aggregative adhesion pattern. A high percentage of animals (28%) shed STEC, corroborating previous knowl-edge and thereby proving the validity of our study. One of the STEC also harboured the LEE pathogenicity island. In addition, eleven animals shed ESBL-producing <it>E. coli</it>.</p> <p>Conclusions</p> <p>While we are aware of the limitations of our survey, our data support the theory, that, in contrast to other Shiga-toxin producing <it>E. coli</it>, cattle are not the reservoir for the O104:H4 outbreak strain or other EAEC, but that the outbreak strain seems to be adapted to humans or might have yet another reservoir, raising new questions about the epidemiology of STEC O104:H4.</p