Observations of dugong reproductive behavior in Trang Province,Thailand: further evidence of intraspecific variation in dugong behavior

The seagrass beds at Muk Island and Talibong Island in Thailand are important areas for dugong (Dugong dugon) feeding and reproduction. We used opportunistic observations during aerial surveys to investigate dugong mating behavior in shallow water areas near Talibong Island on three different days. The mating pattern was categorized by five stages: (1) following: the male followed the female, (2) approaching and stimulating: the male approached and muzzled the female, (3) pairing: both male and female swam in parallel, ventral to ventral or dorsal to dorsal side, (4) mounting: the male copulated with the female, and (5) separating: the male and female swam in different directions. Parental care of calves included one observation of a cow embracing her neonatal calf by the flippers.     

Outcome of prenatally diagnosed trisomy 6 mosaicism

We report the prenatal diagnosis of trisomy 6 mosaicism via amniocentesis, in which trisomy 6 cells were identified in three of five culture vessels with 33% (5/15) of colonies showing trisomic cells. The pregnancy was electively terminated and examination revealed minor abnormalities (shortening of the femurs, micrognathia, posterior malrotation of the ears, and bilateral camptomelia of the second digit of the hands and fifth digits of the feet). Cytogenetic analysis of the placenta showed trisomy 6 in 100% of 20 cells studied. Karyotype was 46,XX in 100 cells examined from fetal skin. There are relatively few prenatally diagnosed cases of mosaic trisomy 6 at amniocentesis. Confined placental mosaicism (CPM) has been postulated in other cases where follow-up cytogenetic studies were not available. The present case differs from those previously reported, as it appears to represent CPM of chromosome 6 with phenotypic effects to the fetus. Copyright © 2002 John Wiley & Sons, Ltd.     

Combined steam-dry reforming of toluene in syngas over CaNiRu/Al2O3 catalysts

Cracking, steam reforming, dry reforming, and combined steam and dry reforming of toluene in model syngas were performed using catalysts to simulate tar removal produced during biomass gasification. The catalysts were prepared by adding Ru, Ca, and Mn to Ni-based catalysts, and their properties were measured using BET, pulse CO chemisorption, XRD and TG. In steam and dry reforming of toluene, a high toluene conversion was observed with increasing Ca content in the catalyst and catalysts containing Ca showed a higher activity than those containing Mn. In combined steam-dry reforming with syngas, 1%CaNiRu/Al₂O₃ indicated a conversion of 93.9% at 800°C.     

Female sex pheromone and male behavioral responses of the bombycid moth <Emphasis Type="Italic">Trilocha varians</Emphasis>: comparison with those of the domesticated silkmoth <Emphasis Type="Italic">Bombyx mori</Emphasis>

Analysis of female sex pheromone components and subsequent field trap experiments demonstrated that the bombycid moth Trilocha varians uses a mixture of (E,Z)-10,12-hexadecadienal (bombykal) and (E,Z)-10,12-hexadecadienyl acetate (bombykyl acetate) as a sex pheromone. Both of these components are derivatives of (E,Z)-10,12-hexadecadienol (bombykol), the sex pheromone of the domesticated silkmoth Bombyx mori. This finding prompted us to compare the antennal and behavioral responses of T. varians and B. mori to bombykol, bombykal, and bombykyl acetate in detail. The antennae of T. varians males responded to bombykal and bombykyl acetate but not to bombykol, and males were attracted only when lures contained both bombykal and bombykyl acetate. In contrast, the antennae of B. mori males responded to all the three components. Behavioral analysis showed that B. mori males responded to neither bombykal nor bombykyl acetate. Meanwhile, the wing fluttering response of B. mori males to bombykol was strongly inhibited by bombykal and bombykyl acetate, thereby indicating that bombykal and bombykyl acetate act as behavioral antagonists for B. mori males. T. varians would serve as a reference species for B. mori in future investigations into the molecular mechanisms underlying the evolution of sex pheromone communication systems in bombycid moths.     

Background monitoring and long-range transport of atmospheric CFC-11 and CFC-12 at Kosan, Korea

The background concentrations of atmospheric CFC-11 and CFC-12were monitored to assess their impact on stratospheric ozone depletion and global warming from September 1995 to March 1999 at Kosan, Korea, located at eastern margin of the Asian Continent. The concentrations of atmospheric CFC-11 at Kosan have decreased slightly, at a rate of –2.5 pptv yr^-1, over the period in response to the Montreal Protocol. The CFC-12 mixing ratio at Kosan continues to increase in the atmosphere at a rate of 5.7 pptv yr^-1 despite international regulations, because of its extreme atmosphere persistence. Recent trends ofthese two chlorofluorocarbons at Kosan, Korea were concordant with those of the northern hemispheric background monitored unitat Mauna Loa, Hawaii. The maximum seasonal mean mixing ratios of CFC-11 and CFC-12 at Kosan, Korea, were 270±4 pptv inthe spring and 538±9 pptv in the winter, and the corresponding seasonal minima were 267±7 and 529±12 pptv. This occurred in the summer and was due to southeasterlywinds from the northwestern Pacific Ocean. By performing a three-day isentropic backward trajectory analysis, it was shownthat air masses at Kosan, and with the exception of summer, mainly originated from central and northern China. In particular, the mixing ratios of these two contaminant speciesare closely related with their air mass trajectories.     

Simultaneous determination of 2-phenylbenzotriazole-type mutagens, PBTA-1 through -8, in river water by liquid chromatography-tandem mass spectrometry

We describe a method for the simultaneous determination of eight kinds of phenylbenzotriazole-type mutagens (PBTA-1, -2, -3, -4, -5, -6, -7 and -8) in river water based on liquid chromatography-tandem mass spectrometry (LC/MS/MS). The application of dopant-assisted atmospheric pressure photoionization (APPI) for the detection of the PBTAs was studied. The APPI technique provided higher PBTA signal intensities than those obtained with an electrospray ionization (ESI) source, and the APPI method was used for the determination of the PBTAs. A solid-phase extraction procedure was used for the extractions of PBTA-1 through -8 from river water. The procedure was rapid and the relative standard deviations were below 15%. The detection limits of PBTA-1 through -8 in river water using the proposed method were found to range from 0.04 to 0.5 ng L(-1) and PBTAs were successfully detected in river water at sub-ng L(-1) levels.