The pheromone-responding conjugative bacteriocin plasmid pPD1 (59 kb) of Enterococcus faecalis was mapped physically by using a relational clone approach, and transposon analysis with Tn917 (Emr) or Tn916 (Tcr) facilitated the location of the bacteriocin-related genes in a segment of about 6.7 kb. Tn917 insertions within a 3-kb region resulted in constitutive clumping. The nucleotide sequence o...

The role of radiation pressure in dust migration and the opening inner cavities transitional disks is revisited this paper. Dust dynamics including often studied axisymmetric models, but work, we show that highly non-axisymmetric features can arise from an instability at disk edge. grains clump into high density there, allowing to leak around them penetrate deeper disk, changing course migratio...

Quantitative constraints on the wind clumping of massive stars can be obtained from the study of the hard X-ray variability of SFXTs. In these systems, a large fraction of the hard Xray emission is emitted in the form of flares with typical duration of 3 ksec, frequency of 7 days and luminosity of 10 ergs/s. Such flares are most probably emitted by the interaction of a compact object orbiting a...

A purified monoclonal antibody (MAb) which specifically reacts with Staphylococcus aureus glucosaminidase was obtained. This MAb was utilized to develop an immunoenzymatic assay for the identification of S. aureus strains. The sensitivity of this assay, based on the simultaneous detection of S. aureus glucosaminidase and protein A, was evaluated by analyzing a total of 196 strains, 26 of which ...

We analyze how spatial heterogeneity in host density affects the advance of vector-borne disease. Infection requires vector infestation. The vector spreads only between hosts occupying the same neighborhood, and the number of hosts varies randomly among neighborhoods. Simulation of a spatially detailed model shows that increasing heterogeneity in host abundance reduces pathogen prevalence. Clum...

Pollen dispersal is a fundamental aspect of plant reproductive biology that maintains connectivity between spatially separated populations. Pollen clumping, a characteristic feature of insect-pollinated plants, is generally assumed to be a detriment to wind pollination because clumps disperse shorter distances than do solitary pollen grains. Yet pollen clumps have been observed in dispersion st...

1. In heart-lung preparations perfused with heparinized blood, clumping of platelets and a sharp fall in the platelet count occurred in the first 5 to 15 minutes after the external circuit was established. 2. In 10 such preparations surviving from 1 to 4 hours, only one showed a return of the platelet count to the level existing before operation. 3. When platelets were reduced in numbers before...