We performed a prospective study of 501 patients, regardless of symptoms, admitted to the hospital, to estimate the predictive value of a negative nasopharyngeal swab for severe acute respiratory coronavirus virus 2 (SARS-CoV-2). At a positivity rate of 10.2%, the estimated negative predictive value (NPV) was 97.2% and the NPV rose as prevalence decreased during the study.

Common and giant ragweed are important weeds of soybeans in Indiana. These two weeds respond differently to imazethapyr POST treatments with common ragweed demonstrating more tolerance than giant ragweed. Both plants show initial susceptibility to imazethapyr, but common ragweed can regrow 10 to 14 days following herbicide application. Laboratory studies were conducted to determine the factors that contribute to the differential control of common and giant ragweed with imazethapyr. Differential absorption was observed at 72 h, with common ragweed absorbing 52% of the applied 14C-imazethapyr and giant ragweed absorbing 39%. The absorption of radioactivity was the same for both species by 672 h. Imazethapyr exhibited both xylem and phloem mobility by translocating both acropetally and basipetally from a treated leaf in giant and common ragweed. A higher percentage of the absorbed radioactivity accumulated in the lower foliage and roots of giant ragweed than common ragweed by 336 h. The rate of imazethapyr metabolism in common ragweed was greater than in giant ragweed. At 336 h, 81 and 68% of the identified radioactivity in the treated leaf was imazethapyr metabolites in common and giant ragweed, respectively. A higher level of the inactive glucose conjugate metabolite was found in the lower plant and root tissues of common ragweed than in giant ragweed. The differential control of common and giant ragweed with foliar applications of imazethapyr was attributed to differences in both translocation and metabolism.

A study was conducted to evaluate the response of common and giant ragweed to postemergence applications of imazethapyr using relative growth rate parameters. The relative growth rate was the same for untreated common and giant ragweed through the 21 d harvest interval. Relative growth rates of treated common and giant ragweed were 50% lower than the relative growth rates of untreated ragweeds 21 d after treatment. Between 21 and 56 d after treatment, the relative growth rate of common ragweed declined an additional 13%, while the relative growth rate of giant ragweed declined an additional 38%. The sharp continued decline in the relative growth rate of giant ragweed indicated plant death. The moderation and slight increase in the relative growth rate of common ragweed between 21 and 56 d corresponded with the initiation of lateral axillary buds and the regeneration of plant growth. Relative growth rate parameters identified differences in the response of common and giant ragweed to imazethapyr as early as 21 d after treatment. Relative growth rate demonstrated utility by objectively measuring differences in the growth response of these two weeds that are moderately susceptible to imazethapyr under laboratory conditions.

We have synthesized nanoporous carbon membranes that have monodisperse pores of 4–5 Å. These membranes have excellent size and shape selectivity that makes them an ideal candidate for use as separators in fuel cells. The selectivity of these membranes to gases such as N2, O2 and water gas [carbon monoxide and hydrogen] were measured using a permeation testing unit. These membranes were then tested as separators in fuel cells.

A finite element analysis applicable to two- and three-dimensional heat flow in samples of arbitrary geometry and composition is presented for use in a thermal wave experiment. The finite element formulation is summarized, including the use of symmetry to simplify the problem, and the governing differential equations for the heat transport are found to be in the form of the Helmholtz equation for the specific case of a modulated heat source. Simulated data for a Nb/Si superlattice is calculated using the finite element code and is shown to agree with predictions from an analytical model, validating the approach taken.