Reduced frequency of embolic signals in severe carotid stenosis with poststenotic flow velocity reduction.

Background: We aimed to investigate the effect of poststenotic low blood flow in patients with recently symptomatic severe carotid stenosis on arterio-arterial embolism.

Methods: Analyses based on a series of 206 consecutive patients (155 men and 51 women, mean age 65.3 years) with a nondisabling ischemic event in the anterior circulation < or =30 days (median 4.

Acute toxicity of fire control chemicals to Daphnia magna (Straus) and Selenastrum capricornutum (Printz).

Acute toxicity tests were conducted exposing Daphnia magna Straus (daphnid) in soft and hard reconstituted waters (hardness 42 and 162 mg/liter as CaCO3, respectively), and Selenastrum capricornutum Printz (algae) in ASTM algal assay medium (hardness 15 mg/liter as CaCO3) to fire retardants Fire-Trol GTS-R, Fire-Trol LCG-R, and Phos-Chek D75-F, and foam suppressants Phos-Check WD-881 and Silv-Ex. The chemicals were slightly toxic to practically harmless to daphnids and moderately toxic to algae. Water quality did not consistently alter the toxicity of the test chemicals to daphnids.

Isotopic tracking of change in diet and habitat use in african elephants.

The carbon, nitrogen, and strontium isotope compositions of elephants in Amboseli Park, Kenya, were measured to examine changes in diet and habitat use since the 1960s. Carbon isotope ratios, which reflect the photosynthetic pathway of food plants, record a shift in diet from trees and shrubs to grass. Strontium isotope ratios, which reflect the geologic age of bedrock, document the concentration of elephants within the park.

The effects of selenium on the distribution of mercury in the organs of the black bullhead (Ictalurus melas).

Following i.p. mercuric chloride injections, the mercury was deposited primarily in the kidneys.

Selenium prevents mercuric chloride induced acute osmoregulatory failure without glutathione peroxidase involvement in the black bullhead (Ictalurus melas).

The relationship between coelomic injections of mercuric chloride doses and osmoregulatory responses was measured. Response parameters were weight increases and blood osmolarity decreases 72 hr after dose administration. Massive edema and large decreases in blood osmolarity could be completely prevented by subcutaneous injections of equimolar sodium selenite.