Occurrence of carcinogenic amino-alpha-carbolines in some environmental samples

The carcinogenic amino-alpha-carbolines, 2-amino-9H-pyrido[2,3-b]indole and AalphaC, have been measured in airborne particles, rain water, soil and cigarette-smoke-polluted indoor air by high-performance liquid chromatography. These carcinogens were found in all kinds of environmental samples examined, although MeAalphaC was not detected in soil. Considering the present results, together with the previous findings that these carcinogens were present in foodstuffs, cigarette smoke and diesel-exhaust particles, amino-alpha-carbolines are likely to be ubiquitous environmental pollutants. Our data also support the hypothesis that amino-alpha-carbolines are formed through combustion of various materials such as food, grass and petroleum.     

Serum PAPP-A and free β-hCG are first-trimester screening markers for down syndrome

Serum measurements of pregnancy-associated plasma protein A (PAPP-A) and the free β-human chorionic gonadotrophin (hCG) subunit were made in 13 women with Down syndrome (DS) pregnancies and six other women with fetal aneuploidy ascertained at chorionic villus sampling (CVS), as well as 89 women with contemporaneous normal control pregnancies. Median serum PAPP-A measurements (0·31 MOM, 95 per cent confidence interval (CI) 0·22–0·65 vs. normal 1·06, 95 per cent CI 0·89–1·20) were lower and free β-hCG subunit measurements (1·13 MOM, 95 per cent CI 0·93–2·63 vs. normal 0·91, 95 per cent CI 0·79–1·03) were higher at statistically significant levels. Receiver operator characteristic (ROC) curves showed that the highest sensitivity for detection, 71·2 per cent (95 per cent CI 54·7–87·6 per cent), was for depressed PAPP-A levels; the combination of low serum PAPP-A levels, maternal age, and elevated free β-hCG levels yielded a detection rate of 78·9 per cent (95 per cent CI 64·9–92·8 per cent) of the affected pregnancies at 8–12 weeks' gestation.     

An estimate of the conversion rates of SO2 to SO2-4 and NO2 to HNO3+ NO3- for the evaluation air pollution in Beijing

The conversion rates of SO₂ to SO^2-₄ and NO₂ to HNO₃₊NO₃- are estimated from the field-data obtained in Beijing in summer, 1988. The results show that the conversion rate of NO₂ is about four times as much as that of SO₂; The conversion rates have a diurnal variation in a day. On the average, the rate of SO₂ is estimated to be 4.7% h^-1 during the daytime and 3.4% h^-1 during the nighttime. Similarly, the rate of NO₂ is estimated to be 17.2% h^-1 and 12% h^-1 respectively.     

Growth characteristics of Parmales (Chrysophyceae) observed in bag cultures

Incubations of natural populations of phytoplankton were carried out in neritic and oceanic areas of the western subarctic Pacific in 1991 and 1992. Algae in the order Parmales, class Chrysophyceae, were observed to increase in number during the incubations. In the light-exposed treatments, the growth rate of Parmales at 5 to 12 °C was 0.012 to 0.016 h^-1 or 0.41 to 0.54 doubling d^-1, which is lower than that of diatoms, but comparable to that of common dinoflagellates. On the other hand, heterotrophic choanoflagellates grew positively in both light and dark at the rate of 0.016 to 0.040 h^-1 or 0.54 to 1.39 doublings d^-1, which is comparable or lower than the reported value at 15 °C. The results obtained demonstrate that the Parmales can grow vegetatively in light and prefer low temperatures.     

Evidence for multiple spawning in the tropical oceanic squid Stenoteuthis oualaniensis (Teuthoidea: Ommastrephidae)

Indirect evidence suggests that Stenoteuthis oualaniensis is a multiple spawner, a reproductive strategy not reported previously for squid. After spawning once, S. oualaniensis apparently continues to feed, grow, and mature additional oocytes before spawning again. Squid were caught by jigging at night in waters around the main Hawaiian Islands during four cruises from 1981 to 1987. All females from 200 mm mantle length (ML) to at least 318 mm ML were sexually mature, indicating that considerable growth takes place after reaching sexual maturity. Size-frequency analyses of ovarian oocytes revealed continuous egg production throughout adult life. Mature ova are stored in the oviducts, but oviduct fullness is unrelated to body size, indicating repeat spawning.     

Degradations of urobilin and stercobilin during activated sludge treatment of night soil

This paper deals with the degradation of urobilin and stercobilin in the sewage treatment plant or domestic septic tank and elucidates the factors contributing to their decomposition. The quantities of urobolin or stercobilin in the effluents from the sewage treatment plants were low and these substances were degraded by treatment with activated sludge. The efficacies of aeration, bacterial decomposition and free chlorine treatment in degrading urobilin or stercobilin were examined. Urobilin and stercobilin were decomposed by aeration and the decomposition rate was accelerated under alkaline conditions. Both compounds were decomposed by activated sludge, isolated bacteria and free chlorine treatments. These results show the decomposition of urobilin and stercobilin at sewage treatment plants.     

Study on anisotropy of effective diffusion coefficient and activation energy for deuterated water in compacted sodium bentonite

To quantify the effects of temperature on the diffusivity of deuterated water (HDO) in compacted sodium bentonite, through-diffusion experiments were conducted at elevated temperatures ranging from 298 to 333 K. Kunipia F (Na-montmorillonite content>98 wt.%; Kunimine Industries) was compacted to a dry density of 0.9 or 1.35 Mg/m(3). As montmorillonite particles were oriented perpendicular to the direction of compaction, the anisotropy of diffusivity was investigated both parallel and normal to the preferred orientation of the montmorillonite. The effective diffusion coefficient D(e) of HDO was larger when the diffusional direction was parallel as opposed to normal to the preferred orientation for both dry densities. The magnitude of D(e) and the anisotropy for HDO were in good accordance with previously reported results for tritiated water at room temperature. Activation energies of D(e) were isotropic and increased with increasing dry density over the range of 19-25 kJ/mol. This relationship was considered to be due to both pore structure development and the high activation energy of water near the montmorillonite surface.     

Modified clean-up for PBDD,PBDF and PBDE with an active carbon column--its application to sediments

A clean-up method for polybrominated dibenzo-p-dioxins (PBDDs), dibenzofurans (PBDFs) and diphenyl ethers (PBDEs) was modified using combinations of multi-layered silica gel, Florisil and active carbon columns. By using active carbon column chromatography in the final procedure, PBDEs were well separated from PBDD/Fs in an elution test with reference standards. We report the application of this method to sediment samples taken from industrialized areas in Japan. These sediments contained PBDEs ranging in concentration from 13 to 2394 pg/g, dry wt. PBDEs did not interfere with the quantification of PBDD/Fs. In addition, PBDEs found in the PBDD/F fraction did not interfere with the identification of PBDFs using the HRGC/HRMS separation method. Some 2,3,7,8-tetra- to hexabrominated dioxins and furans were also detected in the sediment samples.     

Effectiveness of the mating plug in Atrophaneura alcinous (Lepidoptera : Papilionidae)

Summary At mating, males of Atrophaneura alcinous plug the female copulatory duct with a secretory material, but some females copulate several times and can receive spermatophores from different males up to three times. Remating by plugged females mostly takes place shortly after the first mating, when the freshly formed first plug has not completely hardened. A freshly formed plug can be pressed aside or tunneled by the male aedeagus, and thus intromission and subsequent spermatophore transfer are sometimes possible. This is not always the case, however, and larger plugs are more likely to prevent aedeagus intrusion even if they are not completely hardened. Also, a few females remated a day after the first mating or later, when the first plug is already very hard. Completely hardened plugs are more effective than freshly formed ones; later mating males can thrust the aedeagus into the ductus bursae only when the plug is less than ca 1.2 mg (dry weight). The occurrence of female re-mating in plug-forming species thus does not necessarily mean that the plug is ineffective. Offprint requests to: K. Matsumoto