87 research outputs found
Corrections to the Electroweak Effective Action at Finite Temperature
We calculate contributions to the finite temperature effective action for the
electroweak phase transition (EWPT) at \O(g^4), {\it i.e.} at second order in
(g^2 T/\M) and all orders in (g^2 T^2/\M^2). This requires plasma-mass
corrections in the calculation of the effective potential, inclusion of the
``lollipop'' diagram, and an estimate of derivative corrections. We find the
EWPT remains too weakly first-order to drive baryogenesis. We calculate some
one loop kinetic energy corrections using both functional and diagrammatic
methods; these may be important for saddlepoint configurations such as the
bounce or sphaleron.Comment: LaTeX, 6 figures available by email, CALT-68-1795, HUTP-92-A027,
EFI-92-2
Oral Ondansetron Administration in Emergency Departments to Children with Gastroenteritis: An Economic Analysis
Stephen Freedman and colleagues performed a cost analysis of the routine administration of ondansetron in both the United States and Canada and show that its routine administration to eligible children in such settings could provide substantial benefit
In vivo emergence of HIV-1 highly sensitive to neutralizing antibodies.
BACKGROUND: The rapid and continual viral escape from neutralizing antibodies is well documented in HIV-1 infection. Here we report in vivo emergence of viruses with heightened sensitivity to neutralizing antibodies, sometimes paralleling the development of neutralization escape. METHODOLOGY/PRINCIPAL FINDINGS: Sequential viral envs were amplified from seven HIV-1 infected men monitored from seroconversion up to 5 years after infection. Env-recombinant infectious molecular clones were generated and tested for coreceptor use, macrophage tropism and neutralization sensitivity to homologous and heterologous serum, soluble CD4 and monoclonal antibodies IgG1b12, 2G12 and 17b. We found that HIV-1 evolves sensitivity to contemporaneous neutralizing antibodies during infection. Neutralization sensitive viruses grow out even when potent autologous neutralizing antibodies are present in patient serum. Increased sensitivity to neutralization was associated with susceptibility of the CD4 binding site or epitopes induced after CD4 binding, and mediated by complex envelope determinants including V3 and V4 residues. The development of neutralization sensitive viruses occurred without clinical progression, coreceptor switch or change in tropism for primary macrophages. CONCLUSIONS: We propose that an interplay of selective forces for greater virus replication efficiency without the need to resist neutralizing antibodies in a compartment protected from immune surveillance may explain the temporal course described here for the in vivo emergence of HIV-1 isolates with high sensitivity to neutralizing antibodies
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