Fifty strains of Staphylococcus pyogenes were tested for ;coagulase' by the slide method using plasma, serum, and plasmas rendered fibrinogen-free by various methods. It was found that the organisms were clumped by all these reagents. The significance of these findings is discussed.

In June 2009, we used a novel technique to quantify dispersion patterns among a large group of calling male Epomophorus wahlbergi congregated around five neighboring and synchronously fruiting sycamore fig trees (Ficus sycomorus) in Kruger National Park, South Africa by using the physics of sound attenuation over distance to monitor and map positions of calling males without disturbing their ma...

Image segmentation is an important process that separates objects from the background and also from each other. Applied to cells, the results can be used for cell counting which is very important in medical diagnosis and treatment, and biological research that is often used by scientists and medical practitioners. Segmenting 3D confocal microscopy images containing cells of different shapes and...

We identified an Arabidopsis thaliana mutant, clumped chloroplasts 1 (clmp1), in which disruption of a gene of unknown function causes chloroplasts to cluster instead of being distributed throughout the cytoplasm. The phenotype affects chloroplasts and nongreen plastids in multiple organs and cell types, but is detectable only at certain developmental stages. In young leaf petioles of clmp1, wh...

We have analyzed the far-ultraviolet spectrum of two Galactic O4 stars, the O4If+ supergiant HD 190429A and the O4V((f)) dwarf HD 96715, using archival FUSE and IUE data. We have conducted a quantitative analysis based on the two NLTE model atmosphere and wind codes, T and CMFGEN, which incorporate a detailed treatment of NLTE metal line blanketing. From the far-UV spectrum, we have derive...

Multiply substituted isotopic species of nitrous oxide (N2O), referred to as clumped isotopes, represent a promising new tool for distinguishing production pathways this potent greenhouse gas. This work presents the first determination enrichment factors N2O isotopes during bacterial denitrification. Samples obtained after 1-, 3-, and 7-day incubations pure culture denitrifier Pseudomonas aureo...

The stable isotope compositions of biologically precipitated apatite in bone, teeth, and scales are widely used to obtain information on the diet, behavior, and physiology of extinct organisms and to reconstruct past climate. Here we report the application of a new type of geochemical measurement to bioapatite, a "clumped-isotope" paleothermometer, based on the thermodynamically driven preferen...