5,223 research outputs found
Characterization of monoclonal and polyclonal antibodies to bovine enteric coronavirus: Establishment of an efficient ELISA for antigen detection in feces
Monoclonal antibodies to bovine enteric coronavirus (BEC) were produced. Additionally, polyclonal antibodies were made in rabbits and guinea pigs and extracted from the yolk of immunized hens. The antibodies were characterized by neutralization test, hemagglutination inhibition test, enzyme-linked immunosorbent assay (ELISA) and immunoblotting. Neutralizing antibody titers of polyclonal antisera ranged from 1:1280 to 1:40 000. Only one out of 908 hybridoma colonies tested secreted antibodies with neutralizing activity. By ELISA, polyclonal sera exhibited high background reactions that could be significantly reduced by treatment with kaolin in the case of rabbit sera.
Attempts to establish an ELISA for BEC antigen detection based on polyclonal sera failed due to low sensitivity and specificity. Optimal results were achieved when a mixture of two monoclonal antibodies was coated onto microplates for antigen capture, while rabbit hyperimmune serum served as detecting antibodies in an indirect assay.
The combination of the two monoclonal antibodies did not increase sensitivity synergistically, but in a compensatory fashion, probably because of epitope differences between BEC field strain
Rapid identification and differentiation of the vaccine strain Rac H from EHV 1 field isolates using a non-radioactive DNA probe
A method for rapid differentiation between the EHV 1 live vaccine strain Rac H and field isolates is described. Total DNA was isolated from virus-infected small scale cell cultures. DNA fragments digested with restriction endonuclease BamHI were separated, transfered and immobilized on filter membranes. A Digoxigenin-labeled probe derived from EHV 1 was used for hybridization. This probe hybridized specifically to sequences of the inverted terminal repeat region which in case of Rac H include a deletion of 0.8 kb. By comparing the different migration patterns after blot hybridization it could be shown that in 65 isolates from cases of abortion the live vaccine strain Rac H was not involve
The NASA Astrophysics Data System: Data Holdings
Since its inception in 1993, the ADS Abstract Service has become an
indispensable research tool for astronomers and astrophysicists worldwide. In
those seven years, much effort has been directed toward improving both the
quantity and the quality of references in the database. From the original
database of approximately 160,000 astronomy abstracts, our dataset has grown
almost tenfold to approximately 1.5 million references covering astronomy,
astrophysics, planetary sciences, physics, optics, and engineering. We collect
and standardize data from approximately 200 journals and present the resulting
information in a uniform, coherent manner. With the cooperation of journal
publishers worldwide, we have been able to place scans of full journal articles
on-line back to the first volumes of many astronomical journals, and we are
able to link to current version of articles, abstracts, and datasets for
essentially all of the current astronomy literature. The trend toward
electronic publishing in the field, the use of electronic submission of
abstracts for journal articles and conference proceedings, and the increasingly
prominent use of the World Wide Web to disseminate information have enabled the
ADS to build a database unparalleled in other disciplines.
The ADS can be accessed at http://adswww.harvard.eduComment: 24 pages, 1 figure, 6 tables, 3 appendice
Covariant Poisson equation with compact Lie algebras
The covariant Poisson equation for Lie algebra-valued mappings defined in
3-dimensional Euclidean space is studied using functional analytic methods.
Weighted covariant Sobolev spaces are defined and used to derive sufficient
conditions for the existence and smoothness of solutions to the covariant
Poisson equation. These conditions require, apart from suitable continuity,
appropriate local integrability of the gauge potentials and global weighted
integrability of the curvature form and the source. The possibility of
nontrivial asymptotic behaviour of a solution is also considered. As a
by-product, weighted covariant generalisations of Sobolev embeddings are
established.Comment: 31 pages, LaTeX2
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Germany - mind the gap: understanding public opinion and elite interpretations of EU concerns in Germany
Germany has long been viewed as a country of Europhiles, but recently the country has been displaying signs of growing Euroscepticism. When asked to think about Europe, a sizeable minority of Germans expresses concern over a loss of social security or jobs, a loss of national identity and culture, or Germany's financial contributions to the European Union (EU). German political elites across the leftâright spectrum have left these concerns largely unaddressed and continue to advocate for the European project. This raises questions about there being a potential gap between public and elite conceptions of EU fears.
Our comparison of survey data on German public opinion with insights from elite interviews with political leaders reveals that there is indeed a gap between public opinion and elite interpretations of the EU. Political decision-makers across the leftâright spectrum perceive fears in Germany to be largely generalised, non-concrete and unrelated to evaluations of the EU. However, this is the case for a minority of Germans only. The majority show a pattern of concrete, distinguishable concerns, suggesting that we cannot speak about EU fears in the aggregate. Citizens' levels of anxiety are directly related to their evaluations of Germanyâs future strategy in the EU: those who are more worried overall are more likely to want Germany to leave the EU or work towards reducing the EU's powers. While we find citizens' concerns to be dependent on both pragmatic economic evaluations and more emotive variables such as the degree of national and European identification, politicians focus on pragmatic economic evaluations. They underestimate the impact of emotional affiliations as expressed through identity on German public opinion.
Given German political elites' limited understanding of the publicâs concerns, it is not surprising to find that 3âGermany politicians have difficulties addressing them. Although politicians recognise the importance of representation for citizens' evaluations of the legitimacy of the EU, the measures they suggest remain largely one-dimensional, centred on explaining the EUâs procedures and increasing identification with the EU. Politicians, it seems, struggle to think of measures to improve the EU's problem-solving capacity.
In order to close the gap between public and elite conceptions about the EU in Germany, it is crucial to support politicians in their task of understanding and addressing citizens' worries. This requires research and debate on EUrelated concerns, strategies for the transfer of knowledge about their underlying drivers and instruments to facilitate publicâelite interaction about the EU as well as a broader range of policy options to address EU concerns across several levels of governance
The NASA Astrophysics Data System: Architecture
The powerful discovery capabilities available in the ADS bibliographic
services are possible thanks to the design of a flexible search and retrieval
system based on a relational database model. Bibliographic records are stored
as a corpus of structured documents containing fielded data and metadata, while
discipline-specific knowledge is segregated in a set of files independent of
the bibliographic data itself.
The creation and management of links to both internal and external resources
associated with each bibliography in the database is made possible by
representing them as a set of document properties and their attributes.
To improve global access to the ADS data holdings, a number of mirror sites
have been created by cloning the database contents and software on a variety of
hardware and software platforms.
The procedures used to create and manage the database and its mirrors have
been written as a set of scripts that can be run in either an interactive or
unsupervised fashion.
The ADS can be accessed at http://adswww.harvard.eduComment: 25 pages, 8 figures, 3 table
The NASA Astrophysics Data System: The Search Engine and its User Interface
The ADS Abstract and Article Services provide access to the astronomical
literature through the World Wide Web (WWW). The forms based user interface
provides access to sophisticated searching capabilities that allow our users to
find references in the fields of Astronomy, Physics/Geophysics, and
astronomical Instrumentation and Engineering. The returned information includes
links to other on-line information sources, creating an extensive astronomical
digital library. Other interfaces to the ADS databases provide direct access to
the ADS data to allow developers of other data systems to integrate our data
into their system.
The search engine is a custom-built software system that is specifically
tailored to search astronomical references. It includes an extensive synonym
list that contains discipline specific knowledge about search term
equivalences.
Search request logs show the usage pattern of the various search system
capabilities. Access logs show the world-wide distribution of ADS users.
The ADS can be accessed at http://adswww.harvard.eduComment: 23 pages, 18 figures, 11 table
Too close for comfort: spatial patterns in acorn barnacle populations
Spatial patterns in aggregations form as a result of the interplay between costs and benefits experienced by individuals. Such self-organisation of aggregations can be explained using a zonal model in which a short-range zone of repulsion and longer-range zone of attraction surrounding individuals leads to emergent pattern properties. The signal of these processes can be detected using spatial pattern analyses. Furthermore, in sessile organisms, post-settlement mortality reveals the relative costs and benefits of positions within the aggregation. Acorn barnacles are known to require contact with conspecifics for reproduction and are therefore believed to aggregate for this purpose; isolated individuals may also be more susceptible to abiotic stress and predation. At short distances, however, competition for space and resources is likely to occur. In this study spatial patterns of barnacles (Semibalanus balanoides L.) were analysed using pair-correlation functions. Individuals were dispersed at distances below 0.30 cm, but peak relative density occurred at a distance of 0.36 cm from conspecifics. This is much closer than required for reproductive access, implying a strong aggregative drive, up to the point of physical contact with neighbours. Nevertheless, analysis of dead barnacles illustrated that such proximity carries a cost as barnacles with many neighbours were more likely to have died. The inferences obtained from these patterns are that barnacles aggregate as closely as they can, and that local neighbourhood competition is a powerful determinant of mortality. These processes give rise to the observed pattern properties
The NASA Astrophysics Data System: Overview
The NASA Astrophysics Data System Abstract Service has become a key component
of astronomical research. It provides bibliographic information daily, or near
daily, to a majority of astronomical researchers worldwide.
We describe the history of the development of the system and its current
status.
We show several examples of how to use the ADS, and we show how ADS use has
increased as a function of time. Currently it is still increasing
exponentially, with a doubling time for number of queries of 17 months.
Using the ADS logs we make the first detailed model of how scientific
journals are read as a function of time since publication.
The impact of the ADS on astronomy can be calculated after making some simple
assumptions. We find that the ADS increases the efficiency of astronomical
research by 333 Full Time Equivalent (2000 hour) research years per year, and
that the value of the early development of the ADS for astronomy, compared with
waiting for mature technologies to be adopted, is 2332 FTE research years.
The ADS is available at http://adswww.harvard.edu/.Comment: 19 pages, 22 figure
Who wants a referendum on EU membership? Exploring public attitudes in six Member States
Using data from a survey conducted in six EU Member States, we explore what drives citizen demand for referendums on EU membership. We examine whether or not similar drivers and mechanisms can be found across the countries surveyed. We consider what are traditionally understood to be the drivers of euroscepticism, exploring whether those same drivers help to explain demand for referendums on EU membership. Our most important finding is that citizensâ attitudes to EU referendums are not driven, or explained, by a single issue, or by uniform mechanisms cross-nationally. Although we find that trust in EU institutions is a significant predictor of referendum demand, the impact of other factors considered varies substantially across the six countries
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