Mating behavior of the marine copepodOithona davisae

Oithona davisae Ferrari and Orsi were collected from the innermost region of Tokyo Bay, Japan, in 1980 and 1981. The mating behavior of this marine cyclopoid copepod consists of several steps, starting with the paddling of the male in random search of a mate. This behavior is followed by a spiraling movement in pursuance of a mate. Next is the copulatory grasp during which the male grasps the fourth swimming legs of the female partner by means of his first antennae. Whilst in this position, the male's urosome vibrates to allow the spermatophores to extrude from his genital openings. The mating behavior then culminates in the spermatophore transfer. Males do not grasp the uro-some or caudal setae of the mating partner before proper copulatory grasp. The specialized setae of the female's fourth legs may help the male to grasp her legs firmly. Spiraling occurs when the male approaches or traverses the trail of a female that is ready to copulate and that presumably emits a sex-attractant pheromone. The turning radius reduces gradually from more than 1 mm to ca. 0.25 mm as the male approaches the mate female. Females may register spiraling as a mate (male)-approaching signal. Spiraling may lead the male to locate a pheromone source more accurately, and to promote diffusion of the pheromone to prevent other males from pursuing the source. This swimming strategy can increase the copulatory chance of mature virgin females.     

The reaction of nitrogen dioxide with lung surface components: The reaction with cholesterol

The reaction of nitrogen dioxide (NO₂) with cholesterol was investigated. NO₂ reacted with the hydroxyl group in cholesterol to produce cholesteryl nitrite. In this reaction, other minor products were observed. Cholesteryl nitrate, however, was not detected as was reported by other workers. Water accelerates and oxygen retards this reaction.     

Effects of field-applied composted cattle manure and chemical fertilizer on ammonia and particulate ammonium exchanges at an upland field

The present study aimed to investigate the NH₃ volatilization loss from field-applied compost and chemical fertilizer and evaluate the atmosphere–land exchange of NH₃ and particulate NH₄⁺ (pNH₄) at an upland field with volcanic ash soil (Andosol) in Hokkaido, northern Japan. Two-step basal fertilization was conducted on the bare soil surface. First, a moderately fermented compost of cattle manure was applied by surface incorporation (mixing depth, 0–15 cm) at a rate of 117 kg N ha⁻¹ as total nitrogen (T-N) corresponding to 9.9 kg N ha⁻¹ as ammoniacal nitrogen (NH₄–N). Twelve days later, a chemical fertilizer containing 10% (w/w) of NH₄–N as a mixture of ammonium sulfate and ammonium phosphates was applied by row placement (cover depth, 3 cm) at a rate of 100 kg N ha⁻¹ as NH₄–N. The study period was divided into the first-half, beginning after the compost application (CCM period), and the second-half, beginning after the chemical fertilizer application (CF period). The mean air concentrations of NH₃ and pNH₄ (1.5 m height) were 7.6 and 3.0 μg N m⁻³, respectively, in the CCM period; the values were 3.7 and 3.9 μg N m⁻³, respectively, in the CF period. The composition ratios of NH₃ to the sum of NH₃ and pNH₄ (1.5 m height) were 72% and 49% in the CCM and CF periods, respectively. The NH₃ volatilization loss from the compost was 0.8% of the applied T-N (or 9.3% of the applied NH₄–N) and that from the chemical fertilizer was near zero. Excluding the period immediately after the compost application, the upland field acted as a net sink for NH₃ and pNH₄.     

Prenatal diagnosis of infantile hypophosphatasia

Prenatal diagnosis was attempted in a pregnant Japanese woman whose son had died of infantile hypophosphatasia, using chorionic villi sampled at 10 weeks of gestation. Southern blot analysis of restriction fragment length polymorphism was used as a guide, with cDNA for the human liver-type alkaline phosphatase as a probe, and BclI as a restriction enzyme. The fetus was found to be a heterozygote; the pregnancy was allowed to continue; and the baby born was phenotypically normal.     

Levels of Hg and other chemical elements in volcanic ash fall samples erupted from Mt. Sakurajima,Japan

Mt. Sakurajima is a volcanic island in Japan, and a big city, Kagoshima, is quite close to the active volcano. Samples of volcanic ash fall erupted from Mt. Sakurajima were collected at several locations in Kagoshima City and analyzed for Hg and other elements, including major (Mg, Al, Ca, and Fe) and trace elements (V, Cr, Mn, Co, Ni, Zn, As, and Pb). The concentrations of Hg varied from 6.3 to 124 ng g^?1, with the amounts of ash varying from 13 to 1230 g m^?2 month^?1. The Hg concentrations tended to be higher when the monthly amounts of ash fall were lower; other elements did not show such a tendency.     

Contamination by perfluorinated compounds in water near waste recycling and disposal sites in Vietnam

There are very few reports on the contamination by perfluorinated chemicals (PFCs) in the environment of developing countries, especially regarding their emission from waste recycling and disposal sites. This is the first study on the occurrence of a wide range of PFCs (17 compounds) in ambient water in Vietnam, including samples collected from a municipal dumping site (MD), an e-waste recycling site (ER), a battery recycling site (BR) and a rural control site. The highest PFC concentration was found in a leachate sample from MD (360 ng/L). The PFC concentrations in ER and BR (mean, 57 and 16 ng/L, respectively) were also significantly higher than those detected in the rural control site (mean, 9.4 ng/L), suggesting that municipal solid waste and waste electrical and electronic equipment are potential contamination sources of PFCs in Vietnam. In general, the most abundant PFCs were perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), and perfluoroundecanoic acid (PFUDA; <1.4–100, <1.2–100, and <0.5–20 ng/L, respectively). Interestingly, there were specific PFC profiles: perfluoroheptanoic acid and perfluorohexanoic acid (88 and 77 ng/L, respectively) were almost as abundant as PFOA in MD leachate (100 ng/L), whereas PFNA was prevalent in ER and BR (mean, 17 and 6.2 ng/L, respectively) and PFUDA was the most abundant in municipal wastewater (mean, 5.6 ng/L), indicating differences in PFC contents in different waste materials.