Red mangroves emit hydrocarbons

The objective of this study is to investigate hydrocarbon species and amounts released by red mangrove foliage and determine if these quantities warrant future research on atmospheric chemical processing of these compounds. The field investigation took place during July 2001 at Key Largo, Florida Bay, Florida. Foliage still attached to plants was enclosed in cuvettes while air of known flow rates circulated around leaves to study, hydrocarbon emissions. Cuvette air samples underwent gas chromatographic analyses to determine species and amounts of hydrocarbons released by mangrove foliage. Red mangrove foliage emits isoprene and trace amounts of the monoterpenes of alpha-pinene, beta-pinene, camphene, and d-limonene. The mangrove flowers released these latter compounds in amounts ranging from 0.5 to 10 mg (monoterpene) per gram of dry biomass per hour. These fluxes are normalized to, the foliage temperature of 30 degreesC. When normalized to the foliage temperature of 30 degreesC and light levels of 1000 mumol m(-2) s(-1), isoprene emission rates as high as 0.092 +/- 0.109 mug (isoprene) per gram of dry biomass per hour were measured. Compared to terrestrial forest ecosystems, red mangroves are low isoprene emitters. During peak flowering periods in the summertime, however, red mangroves may emit sufficient amounts of monoterpenes to alter ground-level ozone concentrations and contribute to biogenic aerosol formation.

The use of quantitative polymerase chain reaction amplification method to determine sex ratio of human spermatozoa in semen and to determine maternal contamination of amniotic fluid samples

We have modified a technique which uses a single pair of primer sets directed against homologous but distinct genes on the X and Y chromosomes, all of which are coamplified in the same reaction tube with trace amounts of radioactivity. The resulting bands are equal in length, yet distinguishable by restriction enzyme sites generating two independent bands, a 364 bp X-specific band and a 280 bp Y-specific band. A standard curve was generated to show the linear relationship between X/Y ratio average vs. %Y or %X chromosomal content. Of the 51 purified amniocyte DNA samples analyzed, 16 samples showed evidence of high % X contamination while 2 samples demonstrated higher % Y than the expected 50% X and 50% Y chromosomal content. With regards to the 25 processed sperm samples analyzed, X-sperm enrichment was evident when compared to the primary sex ratio whereas Y-sperm was enriched when we compared before and after selection samples.