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

Density Functional Theory of the Hubbard-Holstein Model

We present a density functional theory (DFT) for lattice models with local electron-electron (e-e) and electron-phonon (e-ph) interactions. Exchange-correlation potentials are derived via dynamical mean field theory for the infinite-dimensional Bethe lattice, and analytically for an isolated Hubbard-Holstein site. These potentials exhibit discontinuities as a function of the density, which depend on the relative strength of the e-e and e-ph interactions. By comparing to exact benchmarks, we show that the DFT formalism gives a good description of the linear conductance and real-time dynamics.Comment: 5 pages, 3 figures, supplemental material provided as pd

Death and the City: Chicago's Mortality Transition, 1850-1925

Between 1850 and 1925, the crude death rate in Chicago fell by 60 percent, driven by reductions in infectious disease rates and infant and child mortality. What lessons might be drawn from the mortality transition in Chicago, and American cities more generally? What were the policies that had the greatest effect on infectious diseases and childhood mortality? Were there local policies that slowed the mortality transition? If the transition to low mortality in American cities was driven by forces largely outside the control of local governments (higher per capita incomes or increases in the amount and quality of calories available to urban dwellers from rising agricultural productivity), then expensive public health projects, such as the construction of public water and sewer systems, probably should have taken a back seat to broader national policies to promote overall economic growth. The introduction of pure water explains between 30 and 50 percent of Chicago%u2019s mortality decline, and that other interventions, such as the introduction of the diphtheria antitoxin and milk inspection had much smaller effects. These findings have important implications for current policy debates and economic development strategies.