17,012 research outputs found
To Repair or Replace: That Is The Restorative Question
Objective/Aims: During dental visits, patients spend the majority of their time with their dental hygienist. At these recall appointments the patient’s face-to-face time with the dentist may be short. At this part of the appointment the dentist may diagnose the need for restorative treatment for the patient. Part of the hygienist’s responsibility is to explain treatment options for teeth with restorative needs. The purpose of this review of literature is to provide both options for restoration of dentition to a functional/aesthetic state.
Methods: Studies pertaining to the topic were searched using PubMed database. Keywords used in the search were amalgam, composite, restoration, replace, repair, and contraindications.
Results: Of the references received multiple outcomes has been recorded. Research shows that when it comes to composite restorations generally doctors will replace them in order to get an accurate color shade to match the patient’s teeth. In regards to posterior teeth there are multiple risk factors for repairing amalgam such as endodontic involvement and denture care.
Conclusion: Due to the positive results of both repairing and replacing restorations, it ultimately comes down to a patient to patient basis. Practitioners must also take into consideration risk factors that the patient may present with, cost association/coverage, and patient preference. It is responsibility of the dental hygienist to inform patients of these variables regarding their restorative treatments so they may make an informed decision.https://scholarscompass.vcu.edu/denh_student/1010/thumbnail.jp
Search for Variable Stars in the Globular Cluster M3
We describe here results of a photometric time-sequence survey of the
globular cluster M3 (NGC 5272), in a search for contact and detached eclipsing
binary stars. We have discovered only one likely eclipsing binary and one SX
Phe type star in spite of monitoring 4077 stars with and observing 25
blue stragglers. The newly identified SX Phe star, V237, shows a light curve
with a variable amplitude. Variable V238 shows variability either with a period
of 0.49 d or with a period of 0.25 d. On the cluster colour-magnitude diagram,
the variable occupies a position a few hundredths of magnitude to the blue of
the base of the red giant branch. V238 is a likely descendent of a binary blue
straggler. As a side result we obtained high quality data for 42 of the
previously known RR Lyrae variables, including 33 of Bailey type ab, 7 type c
and 2 double-mode pulsators. We used equations that relate the physical
properties of RRc stars to their pulsation periods and Fourier parameters to
derive masses, luminosities, temperatures and helium parameters for five of the
RRc stars. One of the RRd stars (V79) has switched modes. In previous studies,
it was classified as RRab, but our observations show that it is an RRd star
with the first overtone mode dominating. This indicates blueward evolution on
the horizontal branch.Comment: 21 pages including 14 figures, Latex, requires mn.sty, psfig.sty.
Submitted, MNRA
Bounds on the force between black holes
We treat the problem of N interacting, axisymmetric black holes and obtain
two relations among physical parameters of the system including the force
between the black holes. The first relation involves the total mass, the
angular momenta, the distances and the forces between the black holes. The
second one relates the angular momentum and area of each black hole with the
forces acting on it.Comment: 13 pages, no figure
Time-Symmetric Initial Data for Multi-Body Solutions in Three Dimensions
Time-symmetric initial data for two-body solutions in three dimensional
anti-deSitter gravity are found. The spatial geometry has constant negative
curvature and is constructed as a quotient of two-dimensional hyperbolic space.
Apparent horizons correspond to closed geodesics. In an open universe, it is
shown that two black holes cannot exist separately, but are necessarily
enclosed by a third horizon. In a closed universe, two separate black holes can
exist provided there is an additional image mass.Comment: 12 pages, harvmac macro, minor changes in wordin
Authority, responsibility and process in Australian biodiversity policy
Despite a raft of policies targeting biodiversity, Australia has yet to stem biodiversity decline. This study analyses biodiversity conservation policies in two contrasting Australian landscapes, with a specific emphasis on how authority and responsibility are determined and allocated, using a novel linguistic tool (the Institutional Grammar Tool) and interviews with policymakers. Analysis revealed concerns around the narrowness of authority and the dominance of normative statements rather than rules. Unclear roles and responsibilities further diluted the clarity and allocation of authority. Political and economic factors drive policy implementation and constrain authority in both of the studied regions. A heavy focus on procedures rather than outcomes was also evident. Implications for policy design and the associated authority include broadening the definition of biodiversity, ensuring policy language more clearly allocates responsibilities, paying increased attention to the distributive as well as procedural elements of biodiversity policy, and developing buffering mechanisms to better cope with political and economic drivers
An Exact Conformal Symmetry Ansatz on Kaluza-Klein Reduced TMG
Using a Kaluza-Klein dimensional reduction, and further imposing a conformal
Killing symmetry on the reduced metric generated by the dilaton, we show an
Ansatz that yields many of the known stationary axisymmetric solutions to TMG.Comment: 20 pages, 1 figure, v3: postprint, added one re
All stationary axi-symmetric local solutions of topologically massive gravity
We classify all stationary axi-symmetric solutions of topologically massive
gravity into Einstein, Schr\"odinger, warped and generic solutions. We
construct explicitly all local solutions in the first three sectors and present
an algorithm for the numerical construction of all local solutions in the
generic sector. The only input for this algorithm is the value of one constant
of motion if the solution has an analytic centre, and three constants of motion
otherwise. We present several examples, including soliton solutions that
asymptote to warped AdS.Comment: 42 pages, 9 figures. v2: Changed potentially confusing labelling of
one sector, added references. v3: Minor changes, matches published versio
Building systems-based scenario narratives for novel biodiversity futures in an agricultural landscape
Improving biodiversity futures requires a systems-based appreciation of the dynamic human and bio-physical interactions shaping landscapes. By combining a structured approach to identifying key driversof change on biodiversity with a collaborative approach to scenario planning, biodiversity planners andmanagers can work with stakeholders to identify a range of possible futures and explore their impli-cations. This paper presents an approach to developing scenario narratives constructed against keydrivers of change identified through a social–ecological systems analysis. The approach facilitated theintegration of stakeholder and expert input to inform system dynamics affecting biodiversity outcomes,helping to direct and discipline the collective imagination, and to challenge assumptions and reveal newopportunities and strategies. Examples are provided to show how conventional notions about preser-ving biodiversity remnants “as is” were not a good fit for the diverse range of futures imagined, and thatrestoration ecology would have to expand to incorporate ideas of landscape fluidity and novel ecosys-tems. Aspects of the scenario narratives highlighted the need for new conservation strategies for theendangered native grassland ecological community within the Tasmanian Midlands case study, and are-focusing on new locations across that landscape
Killing Vector Fields in Three Dimensions: A Method to Solve Massive Gravity Field Equations
Killing vector fields in three dimensions play important role in the
construction of the related spacetime geometry. In this work we show that when
a three dimensional geometry admits a Killing vector field then the Ricci
tensor of the geometry is determined in terms of the Killing vector field and
its scalars. In this way we can generate all products and covariant derivatives
at any order of the ricci tensor. Using this property we give ways of solving
the field equations of Topologically Massive Gravity (TMG) and New Massive
Gravity (NMG) introduced recently. In particular when the scalars of the
Killing vector field (timelike, spacelike and null cases) are constants then
all three dimensional symmetric tensors of the geometry, the ricci and einstein
tensors, their covariant derivatives at all orders, their products of all
orders are completely determined by the Killing vector field and the metric.
Hence the corresponding three dimensional metrics are strong candidates of
solving all higher derivative gravitational field equations in three
dimensions.Comment: 25 pages, some changes made and some references added, to be
published in Classical and Quantum Gravit
Effect of optical disorder and single defects on the expansion of a Bose-Einstein condensate in a one-dimensional waveguide
We investigate the one-dimensional expansion of a Bose-Einstein condensate in
an optical guide in the presence of a random potential created with optical
speckles. With the speckle the expansion of the condensate is strongly
inhibited. A detailed investigation has been carried out varying the
experimental conditions and checking the expansion when a single optical defect
is present. The experimental results are in good agreement with numerical
calculations based on the Gross-Pitaevskii equation.Comment: 5 pages, 5 figure
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