3,592 research outputs found
Holliday junction resolvase in Schizosaccharomyces pombe has identical endonuclease activity to the CCE1 homologue YDC2
A novel Holliday junction resolving activity has been identified in fractionated cell extracts of the fission yeast Schizosaccharomyces pombe . The enzyme catalyses endonucleolytic cleavage of Holliday junction-containing chi DNA and synthetic four-way DNA junctions. The activity cuts with high specificity a synthetic four-way junction containing a 12 bp core of homologous sequences but has no activity on another four-way junction (with a fixed crossover point), a three-way junction, linear duplex DNA or duplex DNA containing six mismatched nucleotides in the centre. The major cleavage sites map as single nicks in the vicinity of the crossover point, 3' of a thymidine residue. These data indicate that the activity has a strong DNA structure selectivity as well as a limited sequence preference; features similar to the Holliday junction resolving enzymes RuvC of Escherichia coli and the mitochondrial CCE1 (cruciform-cuttingenzyme 1) of Saccharomyces cerevisiae. A putative homologue of CCE1 in S.pombe (YDC2_SCHPO) has been identified through a search of the sequence database. The open reading frame of this gene has been cloned and the encoded protein, YDC2, expressed in E.coli . The purified recombinant YDC2 exhibits Holliday junction resolvase activity and is, therefore, a functional S.pombe homologue of CCE1. The resolvase YDC2 shows the same substrate specificity and produces identical cleavage sites as the activity obtained from S. pombe cells. Both YDC2 and the cellular activity cleave Holliday junctions in both orientations to give nicks that can be ligated in vitro. The partially purified Holliday junction resolving enzyme in fission yeast is biochemically indistinguishable from recombinant YDC2 and appears to be the same protein
Corporate separateness
Banking structure ; Bank affiliates ; Bank holding companies
Tasers and Use of Force: Hitting a Moving Target
Law enforcement officers experience dynamic and sometimes dangerous encounters while performing their duties. To combat this, society gives them the authority to use reasonable force to accomplish their lawful objectives and law enforcement agencies provide them the tools and the training to effectively manage the incident. The use of force by law enforcement officers is guided by factors locally, state-wide, and nationally through policy, statute, and regulation. Law enforcement administrations have an impact on the use of force by an organization’s members through formal means such as policy, and informal means such as organizational culture. Administrative views are guided by internal and external factors including legislation, regulations, mission, ethics, and stakeholders. Officers’ duties are frequently guided by codified structures, such as statute and policy, but they must use discretion to fill in the blanks of how to act when not explicitly dictated. It is within these blanks that a robust ethical framework is critical to ensure the officer’s actions reflect the values of the organization and the profession. Perhaps the entity with the most impact on the use of force by law enforcement is the court system through case law. This paper will review how these different factors impact the use of force by law enforcement, and specifically, the use of electronic control weapons
Evidence for transfer followed by breakup in 7Li + 65Cu
The observation of a large cross-section for the alpha + d channel compared
to breakup into the alpha + t channel from an exclusive measurement for the
7Li+65Cu system at 25 MeV is presented. A detailed analysis of the angular
distribution using coupled channels Born approximation calculations has
provided clear evidence that the observed alpha + d events arise from a two
step process, i.e. direct transfer to the 2.186 MeV (3+) resonance in the alpha
+ d continuum of 6Li followed by breakup, and are not due to final state
interaction effects.Comment: 12 pages, 3 figures, To be published in Phys. Letts.
Near-barrier Fusion Induced by Stable Weakly Bound and Exotic Halo Light Nuclei
The effect of breakup is investigated for the medium weight
Li+Co system in the vicinity of the Coulomb barrier. The strong
coupling of breakup/transfer channels to fusion is discussed within a
comparison of predictions of the Continuum Discretized Coupled-Channels model
which is also applied to He+Co a reaction induced by the borromean
halo nucleus He.Comment: 6 pages, 3 figures. A talk given at the FUSION06: International
Conference on Reaction Mechanisms and Nuclear Structure at the Coulomb
barrier, March 19-23, 2006, San Servolo, Venezia, Ital
Solar seismology. I. The stability of the solar p-modes
We investigate the stability of the radial p-modes of the Sun by computing nonadiabatic eigen-values and e1genfunctions for a solar envelope model which extends from an inner radius r ≈ 0.3 R_☉ out to an optical depth r ≈ 3 x 10^(-4). Our calculations take into account in a crude
fashion the response of the convective flux to the oscillation. The dynamical effect of turbulence in the convection zone is parametrized in terms of a turbulent shear viscosity. The results of our calculations are as follows. If damping by turbulent viscosity is neglected,
all modes with penriods longer than 6 minutes are unstable. The familiar K-mechanism, which operates in the H ionization-H^- opacity region, is the dominant source of driving of the oscillations. Modes with periods shorter than 6 minutes are stabilized by radiative damping in the solar atmosphere. When turbulent dissipation of pulsational energy is included, all modes are predicted to be stable. However, the margin of stability is very small. In view of the large uncertainty that must be assigned to our estimate of turbulent damping, we conclude that theoretical calculations cannot unequivocally resolve the question of the stability of the solar p-modes
Cluster Model for Near-barrier Fusion Induced by Weakly Bound and Halo Nuclei
The influence on the fusion process of coupling transfer/breakup channels is
investigated for the medium weight Li+Co systems in the vicinity
of the Coulomb barrier. Coupling effects are discussed within a comparison of
predictions of the Continuum Discretized Coupled-Channels model. Applications
to He+Co induced by the borromean halo nucleus He are also
proposed.Comment: 5 pages, 3 figures, FINUSTAR2 Conference, Aghios Nikolaus, Crete,
Greece. 10-14 September 200
Climate Change in Northern New Hampshire: Past, Present and Future
EARTH’S CLIMATE CHANGES. It always has and always will. However, an extensive and growing body of scientific evidence indicates that human activities—including the burning of fossil fuel (coal, oil, and natural gas) for energy, clearing of forested lands for agriculture, and raising livestock—are now the primary force driving change in the Earth’s climate system. This report describes how the climate of northern New Hampshire has changed over the past century and how the future climate of the region will be affected by a warmer planet due to human activities
- …