6,249 research outputs found
Adenosine to inosine editing by ADAR2 requires formation of a ternary complex on the GluR-B R/G site
RNA editing by members of the ADAR (adenosine deaminase that acts on RNA) enzyme family involves hydrolytic deamination of adenosine to inosine within the context of a double-stranded pre-mRNA substrate. Editing of the human GluR-B transcript is catalyzed by, the enzyme ADAR2 at the Q/R and R/G sites. We have established a minimal RNA substrate for editing based on the RIG site and have characterized the interaction of ADAR2 with this RNA by gel shift, kinetic, and cross-linking analyses. Gel shift analysis revealed that two complexes are formed on the RNA as protein concentration is increased; the ADAR monomers can be crosslinked to one another in an RNA-dependent fashion. We performed a detailed kinetic study of the editing reaction; the data from this study are consistent with a reaction scheme in which formation of an ADAR2.RNA ternary complex is required for efficient RNA editing and in which formation of this complex is rate determining. These observations suggest that RNA adenosine deaminases function as homodimers on their RNA substrates and may partially explain regulation of RNA editing in these systems
How Some Islamic Monarchies Use Religious Ideology to Maintain Domestic Control and Exert Regional Influence: a comparative study of Morocco and Saudi Arabia
This paper will attempt to explore the ways in which, and the purposes with which, some authoritarian states seek to use religious ideologies to maintain domestic control and exert regional influence. The two case studies explored here are Morocco and Saudi Arabia, two Arabo-Islamic monarchies in the Middle East/North Africa (MENA) region. This paper will touch on historical contexts in which modern religious educational apparatuses were developed and the contemporary contexts in which they now exist, as well as the intents and desires behind such apparatuses. In addition, this paper will explore the benefits of ideological control in a domestic and international sense
Regulating speech on the internet
This paper considers the way in which traditional legal tools for regulating speech have been applied in the Internet environment. The paper commences by describing the aspects of this environment which are regarded as attracting regulatory interest. It then moves on to consider the way in which the regimes of defamation law, censorship law and intellectual property law impact on the Internet. Through this examination the paper raises the question of the appropriateness of the current approach of regulation by analogy
Journalistic parody and moral rights under Australian copyright law
Parody achieves its effect through a borrowing of a text which is then satirised by placing it in an inappropriate context or by caricaturing its theme. This borrowing has been a tool of journalism from the beginnings of that profession. However, this borrowing has begun to be subject to the scrutiny of copyright law. This article examines the impact of copyright law upon journalistic parody’. Selected for particular scrutiny are parodies involving the false attribution of authorship and passing off. The article examines the impact upon journalistic parody’ of the moral rights provisions of the Copyright Amendment Bill 1997
Receptor Mechanisms Common to Platelets and Platelet Progenitor Cells
Blood platelets are small, anucleate cells which circulate freely in the cardiovascular system. One of their major physiological functions is concerned with haemostasis - the cessation of bleeding. However, platelets are also involved in the pathological counterpart of haemostasis - thrombosis. Platelets are derived from megakaryocytes which are large nucleated cells located in the bone marrow
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Performance gains and losses from network centrality in cluster located firms: a longitudinal study
This paper develops and tests theoretically derived arguments on the performance trade-offs that arise when firms located inside geographical clusters broaden their cluster networks and increase their centrality. Using three-year longitudinal data gathered on a sample of 89 small media firms located in a geographical cluster of Northern Italy, we model growth in revenues and in employees as a function of their centrality in different types of networks. We find an inverted U-shaped effect of centrality across all types of networks. We also find strong evidence of negative interactivity between network types in predicting sales and employee growth. This result not only concurs with the view that centrality brings tangible and intangible benefits, but also provides empirical support for the contention that centrality fosters dispositions and disturbances that undermine performance
A serological survey of ruminant livestock in Kazakhstan during post-Soviet transitions in farming and disease control
The results of a serological survey of livestock in Kazakhstan, carried out in 1997–1998, are reported. Serum samples from 958 animals (cattle, sheep and goats) were tested for antibodies to foot and mouth disease (FMD), bluetongue (BT), epizootic haemorrhagic disease (EHD), rinderpest (RP) and peste des petits ruminants (PPR) viruses, and to Brucella spp. We also investigated the vaccination status of livestock and related this to changes in veterinary provision since independence in 1991. For the 2 diseases under official surveillance (FMD and brucellosis) our results were similar to official data, although we found significantly higher brucellosis levels in 2 districts and widespread ignorance about FMD vaccination status. The seroprevalence for BT virus was 23%, and seropositive animals were widespread suggesting endemicity, despite the disease not having being previously reported. We found a few seropositives for EHDV and PPRV, which may suggest that these diseases are also present in Kazakhstan. An hierarchical model showed that seroprevalence to FMD and BT viruses were clustered at the farm/village level, rather than at a larger spatial scale. This was unexpected for FMD, which is subject to vaccination policies which vary at the raion (county) level
Black holes and Galactic density cusps -- I. Radial orbit cusps and bulges
In this paper, we study the distribution functions that arise naturally
during self-similar radial infall of collisionless matter. Such matter may be
thought of either as stars or as dark matter particles. If a rigorous steady
state is assumed, then the system is infinite and is described by a universal
distribution function given the self-similar index. The steady logarithmic
potential case is exceptional and yields the familiar Gaussian for an infinite
system with an inverse-square density profile. We show subsequently that for
time-dependent radial self-similar infall, the logarithmic case is accurately
described by the Fridmann and Polyachenko distribution function. The system in
this case is finite but growing. We are able to embed a central mass in the
universal steady distribution only by iteration, except in the case of massless
particles. The iteration yields logarithmic corrections to the massless
particle case and requires a `renormalization' of the central mass. A central
spherical mass may be accurately embedded in the Fridmann and Polyachenko
growing distribution however. Some speculation is given concerning the
importance of radial collisionless infall in actual galaxy formation.Comment: 10 pp, 3 fig
S-cone signals invisible to the motion system can improve motion extraction via grouping by color
Peer reviewedPublisher PD
The Existence of Sterile Neutrino Halos in Galactic Centers as an Explanation of the Black Hole mass - Velocity Dispersion Relation
If sterile neutrinos exist and form halos in galactic centers, they can give
rise to observational consequences. In particular, the sterile neutrinos decay
radiatively and heat up the gas in the protogalaxy to achieve hydrostatic
equilibrium, and they provide the mass to form supermassive blackholes. A
natural correlation between the blackhole mass and velocity dispersion thus
arises with and .Comment: Accepted in Ap
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