Deconvoluting the effects of surface chemistry and nanoscale topography: Pseudomonas aeruginosa biofilm nucleation on Si-based substrates.

Hypothesis: The nucleation of biofilms is known to be affected by both the chemistry and topography of the underlying substrate, particularly when topography includes nanoscale (<100 nm) features. However, determining the role of topography vs. chemistry is complicated by concomitant variation in both as a result of typical surface modification techniques.

Gerontological nurse practitioners (GNPs) for the first time in Israel: Physicians' and nurses' attitudes.

Purpose: Nurse practitioners (NPs) have recently been partially introduced by the Israel Ministry of Health. This study examines the attitudes among gerontological physicians and nurses toward the scope of practice and effects on healthcare quality of the new role of gerontological NPs (GNPs).

Data Sources: A descriptive survey methodology, with a cross-sectional design, was used.

Essential is not irreplaceable: fitness dynamics of experimental E. coli RNase P RNA heterologous replacement.

While critical cellular components-such as the RNA moiety of bacterial ribonuclease P-can sometimes be replaced with a highly divergent homolog, the cellular response to such perturbations is often unexpectedly complex. RNase P is a ubiquitous and essential ribonucleoprotein involved in the processing of multiple RNA substrates, including tRNAs, small non-coding RNAs and intergenic operons. In Bacteria, RNase P RNAs have been subdivided-based on their secondary and tertiary structures-into two major groups (A and B), each with a distinct phylogenetic distribution.

The evolutionary histories of clinical and environmental SHV β-lactamases are intertwined.

The rise of antibiotic-resistant pathogens focuses our attention on the source of antibiotic resistance genes, on the existence of these genes in environments exposed to little or no antibiotics, and on the relationship between resistance genes found in the clinic and those encountered in non-clinical settings. Here, we address the evolutionary history of a class of resistance genes, the SHV β-lactamases. We focus on bla SHV genes isolated both from clinical and non-clinical sources and show that clinically important resistance determinants arise repeatedly from within a diverse pool of bla SHV genes present in the environment.