91 research outputs found
Corrective Primary Impression Technique
The article describes a simple, quick and corrective technique for making the preliminary impression. It records the extensions better as compared to the impressions made using only impression compound. This technique is accurate and gives properly extended custom tray. Any deficiencies seen in the compound primary impression are corrected using this technique hence, this technique is called as a “corrective primary impression technique”
Relativistic Green's function approach to charged-current neutrino-nucleus quasielastic scattering
A relativistic Green's function approach to inclusive quasielastic
charged-current neutrino-nucleus scattering is developed. The components of the
hadron tensor are written in terms of the single-particle Green's function,
which is expanded on the eigenfunctions of the nuclear optical potential, so
that final state interactions are accounted for by means of a complex optical
potential but without a loss of flux. Results for the (neutrino_mu, mu-)
reaction on 16O and 12C target nuclei are presented and discussed. A reasonable
agreement of the flux-averaged cross section on 12C with experimental data is
achieved.Comment: 7 pages, 4 figure
Relativistic Green's function approach to parity-violating quasielastic electron scattering
A relativistic Green's function approach to parity-violating quasielastic
electron scattering is presented. The components of the hadron tensor are
expressed in terms of the single particle Green's function, which is expanded
in terms of the eigenfunctions of the non-Hermitian optical potential, in order
to account for final state interactions without any loss of flux. Results for
C, O, and Ca are presented and discussed. The effect of
the strange quark contribution to the nuclear current is investigated.Comment: 24 pages, 13 figure
Antisymmetrized Green's function approach to reactions with a realistic nuclear density
A completely antisymmetrized Green's function approach to the inclusive
quasielastic scattering, including a realistic one-body density, is
presented. The single particle Green's function is expanded in terms of the
eigenfunctions of the nonhermitian optical potential. This allows one to treat
final state interactions consistently in the inclusive and in the exclusive
reactions. Nuclear correlations are included in the one-body density. Numerical
results for the response functions of O and Ca are presented and
discussed.Comment: 45 pages, 3 figure
Analysis of exchange terms in a projected ERPA Theory applied to the quasi-elastic (e,e') reaction
A systematic study of the influence of exchange terms in the longitudinal and
transverse nuclear response to quasi-elastic (e,e') reactions is presented. The
study is performed within the framework of the extended random phase
approximation (ERPA), which in conjuction with a projection method permits a
separation of various contributions tied to different physical processes. The
calculations are performed in nuclear matter up to second order in the residual
interaction for which we take a (pi+rho)-model with the addition of the
Landau-Migdal g'-parameter. Exchange terms are found to be important only for
the RPA-type contributions around the quasielastic peak.Comment: 29 pages, 6 figs (3 in postscript, 3 faxed on request), epsf.st
Pervasive Sign Epistasis between Conjugative Plasmids and Drug-Resistance Chromosomal Mutations
Multidrug-resistant bacteria arise mostly by the accumulation of plasmids and chromosomal mutations. Typically, these resistant determinants are costly to the bacterial cell. Yet, recently, it has been found that, in Escherichia coli bacterial cells, a mutation conferring resistance to an antibiotic can be advantageous to the bacterial cell if another antibiotic-resistance mutation is already present, a phenomenon called sign epistasis. Here we study the interaction between antibiotic-resistance chromosomal mutations and conjugative (i.e., self-transmissible) plasmids and find many cases of sign epistasis (40%)—including one of reciprocal sign epistasis where the strain carrying both resistance determinants is fitter than the two strains carrying only one of the determinants. This implies that the acquisition of an additional resistance plasmid or of a resistance mutation often increases the fitness of a bacterial strain already resistant to antibiotics. We further show that there is an overall antagonistic interaction between mutations and plasmids (52%). These results further complicate expectations of resistance reversal by interdiction of antibiotic use
What Do Community Benefits Agreements Deliver? Evidence From Los Angeles
Problem, research strategy, and findings: Advocates of community benefits agreements (CBAs) between coalitions of nongovernmental organizations (NGOs) and real estate developers contend that CBAs promote public accountability and responsiveness to community concerns. This study assesses the Los Angeles Sports and Entertainment District (LASED) CBA, which scholars and practitioners have described as a model for such agreements. I assess compliance with key provisions of the agreement related to jobs, affordable housing, and parks and recreational facilities. I also assess whether compliance with these provisions has yielded benefits beyond those required under existing laws and regulations. I find that the parties to the agreement have technically complied with many, although arguably not all, of its provisions. But some of the provisions in the CBA are not legally binding, other provisions overlap with requirements that the developer would have had to satisfy even without the CBA, and some reports required by the CBA are unavailable. As a result, outcomes such as living wage jobs and funding for affordable housing units are not clearly attributable to the CBA; other outcomes, such as targeted hiring, are unknown due to a lack of relevant information.Takeaway for practice: Although CBAs may not fulfill all the claims that advocates make on their behalf, they can play important roles in community development by directing public and private spending to underserved neighborhoods. But collecting and verifying the relevant data may be challenging, even if reporting requirements are clearly spelled out in the CBA. As the complexity of a CBA increases, so do the challenges of assessing outcomes and assigning responsibility for those outcomes
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