Estrogen equivalent concentration of individual isomer-specific 4-nonylphenol in Ariake sea water, Japan

Concentrations of 4-nonylphenol (NP) were determined by isomer-specific quantification of individual NP isomers based on relative response factor (RRF) quantification with GC–MS in combination with steam distillation extraction. Concentrations of NP in the Ariake Sea decreased with distance from the river mouth (St.A; 49 ng NP/l) to offshore areas (St.C; 11 ng NP/l). Even the least concentration in water from St.C in Ariake Sea was sufficient to have adverse effects on barnacles. The isomers, NP1–NP14 were separated by GC–PFC and identified structurally with NMR. The isomers varied in estrogenic activity with NP7 exhibiting the greatest estrogenic activity with a potency that was approximately 1.9 × 10⁻³ that of 17β-estradiol (E2) in recombinant yeast screen system. The coefficient of variation (CV) of NP isomer’s concentrations among three samples at St.A, B and C were 4–75%. This suggests that NP isomers might be independently degraded in aquatic environmental samples. The predicted estrogenic activity of measured concentrations of NP in Ariake Sea was 2.7–3.0-fold greater than the measured estrogen agonist activity.     

Absolute magnitudes of late-type stars

The improved calibration of absolute magnitude versus spectral type and luminosity class is presented for carbon stars and for K- to M-type giants. It is based on the recent results estimated by applying the maximum-likelihood method and other statistical methods to the homogeneous kinematical data including the proper motions in the AGK3 system.Paper presented at the IAU Third Asian-Pacific Regional Meeting, held in Kyoto, Japan, between 30 September–6 October, 1984.     

Microearthquakes along the back-arc spreading system in the eastern Bismarck Sea

OBS's were deployed for 26 to 29 days in the eastern Bismarck Sea to investigate the back-arc spreading. Hypocenters of 186 shallow earthquakes were determined using P- and S-waves from at least five stations. In the western survey area, a transform fault zone is marked by a linear micro-earthquake activity striking N65°W and less than 5 km wide. The predominant type of their focal mechanisms is strike-slip. In the eastern area, several intermittent zones of micro-earthquakes and their strike-slip type focal mechanisms suggest the location of short-length transform faults separating en-echelon spreading ridges.     

Tectonic stress field in East Eurasia

The overall pattern of the recent tectonic stress field in the eastern part of the Eurasian plate is inferred from the geological features of large transcurrent and reverse faults, graben structures and from focal mechanism solutions of shallow earthquakes. NE-SW striking trajectory lines, of maximum horizontal tectonic stress axis (σ Hmax), are estimated at the north of Tibet and mainland China, but its strike turns to easterly near the eastern margin of the Eurasian plate. This suggests that the main origin of the σ Hmax in East Eurasia is due to a compressive stress regime along, the Himalayan belt, Tibet and the Japan Trench (and also the Sakhalin and Nankai Trough). This tectonic stress field seems to provide some influence on the extensional tectonics in the Shansi region, Baikal, and also in the Okinawa Trough where the N-S opening has been confirmed. The systematic view of the tectonic stress field in East Eurasia, makes it possible to appreciate the fundamental background of a number of complicated intra-plate tectonics.