The percolation phase transition in sea Ice

Sea ice exhibits a marked transition in its fluid transport properties at a critical brine volume fraction pc of about 5 percent, or temperature Tc of about -5 degreesC for salinity of 5 parts per thousand. For temperatures warmer than Tc, brine carrying heat and nutrients can move through the ice, whereas for colder temperatures the ice is impermeable. This transition plays a key role in the geophysics, biology, and remote sensing of sea ice. Percolation theory can be used to understand this critical behavior of transport in sea ice. The similarity of sea ice microstructure to compressed powders is used to theoretically predict pc of about 5 percent.     

Pneumonia associated with Mycoplasma spp in three cats

Mycoplasma spp were isolated in pure culture from bronchoalveolar lavage specimens from three cats with clinical, cytological and radiographic signs of bron-chopneumonia or suppurative bronchitis. Predisposing factors were not identified in the first case, the second cat had oesophageal hypomotility, while the third cat had been exposed to cigarette smoke and had advanced periodontal disease. Respiratory signs resolved promptly and completely in all cases following antimicrobial therapy directed against mycoplasmas. Mycoplasma spp are possible causes of lower respiratory tract disease in cats and this should be considered when selecting empirical therapy for feline airway disease and pneumonia. In some situations mycoplasmas may behave as primary lower respiratory tract pathogens in cats.