Vertical distribution of <Emphasis Type="Italic">Todarodes pacificus</Emphasis> (Cephalopoda: Ommastrephidae) paralarvae near the Oki Islands,southwestern Sea of Japan

The diel vertical distribution patterns of Japanese common squid, Todarodes pacificus, paralarvae were examined using a Multiple Opening Closing Net and Environmental Sensing System (MOCNESS) in the southwest Sea of Japan near the Oki Islands (Japan) during five late-autumn surveys in 1998–2002. A total of 1,511 paralarvae ranging in mantle length (ML) from 0.7 to 7.3 mm were collected at 63 of the 68 stations surveyed. Most (84%) were collected above 75 m depth and in the mixed layer. The vertical distribution patterns varied little between day and night. Hatchling-sized (<1.0 mm ML) paralarvae were abundant at 0–25 m depth, and paralarval ML increased with increasing sampling depth. Our results suggest that T. pacificus paralarvae do not exhibit large diel vertical migration patterns, but as they increase in size, paralarvae gradually descend in the water column and the variability in depth increases with ontogeny.     

Ground level ozone concentrations and its association with NOx and meteorological parameters in Kathmandu valley, Nepal

This paper summarizes the results of a yearlong continuous measurements of gaseous pollutants, NO, NO₂, NO_x and O₃ in the ambient air at Kathmandu valley. Measured concentration of the pollutants in study area is a function of time. NO, NO₂ and O₃ peak occurred in succession in presence of sunlight. At the time of maximum O₃ concentration most of the NO_x are utilized. The diurnal cycle of ground level ozone concentrations, revealed mid-day peak with lower nocturnal concentrations and inverse relationship exists between O₃ and NO_x, which are evidences of photochemical O₃ formation. The observed ground level ozone during monsoon is slight lower than the pre-monsoon value. Further, lack of rainfall and higher temperature, solar radiation in the pre-monsoon have given rise to the gradual build up of ozone and it is lowest during winter. Ground level ozone concentrations measured during bandha (general strike) and weekend are 19% and 13% higher than those measured during weekdays. The most effective ozone abatement strategy for Kathmandu Valley may be control of NO_x emissions.     

Contamination status and accumulation features of persistent organochlorines in pet dogs and cats from Japan

Concentrations of persistent organochlorines (OCs) such as polychlorinated dibenzo-p-dioxin (PCDDs), dibenzofurans (PCDFs), biphenyls, dichlorodiphenyltrichloroethane and their metabolites (DDTs), hexachlorocyclohexane isomers, hexachlorobenzene, and chlordane compounds were determined in genital organs of pet dogs and cats and pet foods from Japan. Levels of OCs in dogs were relatively lower than those in cats, while residue levels in their diets were almost similar, implying that accumulation and elimination mechanisms of these contaminants are different between dogs and cats. When bioconcentration factors (BCFs) were estimated from concentrations of OCs in dogs, cats, and their diets, BCFs of all the OCs except PCDD/DFs exceeded 1.0 in cats. On the other hand, in all the dogs, BCFs of DDTs were below 1.0, suggesting that dogs do not bioconcentrate DDTs. Furthermore, BCFs of all the OCs except PCDD/DFs in dogs were notably lower than those in cats, suggesting that dogs have higher metabolic and elimination capacity for these contaminants than cats. When residue levels of OCs in livers, adipose tissue, and genital organs of two pet dogs were examined, hepatic sequestration of PCDD/DFs and oxychlordane was observed.     

The outcome of pregnancy and prenatal chromosomal diagnosis of fetuses in couples including a translocation carrier

In order to evaluate the relation between chromosomal translocation and the outcome of pregnancy, 50 couples were examined. Subjects consisted of 35 couples that included a reciprocal translocation carrier; 13 included a Robertsonian translocation carrier and 2 included a carrier of a mosaic reciprocal translocation. The reasons for performing chromosomal examinations were mainly infertility and abnormality of neonates. The rates of miscarriages and neonatal abnormalities in prior pregnancies were significantly higher than the birth rate of morphologically normal newborns. The presence of a translocation is closely related to reproductive failure because of the chromosomal imbalance. However, prenatal chromosomal examination after the 15th gestational week in subsequent pregnancies revealed that almost half of the fetuses showed normal karyotypes and only 12.8 per cent of the fetuses showed a chromosomal imbalance. Many chromosomally imbalanced fetuses are spontaneously aborted before amniocentesis. The risk of chromosomal imbalance is relatively low in prenatal diagnosis, but partial trisomies of small rearrangements tend to be preserved.     

Prenatal diagnosis of tyrosinase-negative oculocutaneous albinism by an electron microscopic dopa reaction test of fetal skin

An electron microscopic DOPA reaction test of fetal skin was used for the prenatal diagnosis of tyrosinase-negative oculocutaneous albinism (OCA). The subject was a 34-year-old Japanese woman in her second pregnancy. Her first child, born in 1982, had been previously examined and confirmed to have tyrosinase-negative OCA. The parents requested a prenatal diagnosis and we sampled skin from the upper trunk of the fetus. On conventional electron microscopy, the development of melanosomes in interfollicular melanocytes had progressed no further than stage II. Fetal skin samples incubated with L-DOPA solution indicated a lack of tyrosinase activity and showed that the melanosomes had not progressed beyond stage II. In skin samples from the trunks of three Japanese fetuses aborted for other reasons at 19–20 weeks of gestation, most premature melanosomes were further melanized to stage IV after incubation with L-DOPA solution. A prenatal diagnosis of tyrosinase-negative OCA was made. The parents requested a termination and skin biopsies of the abortus confirmed the diagnosis. This study shows that tyrosinase is normally present in melanocytes of the fetal epidermis at 20 weeks' gestation, and that the electron microscopic DOPA reaction test of a fetal skin biopsy specimen is safe and practical, and provides reliable information for making a prenatal diagnosis of tyrosinase-negative OCA in the second trimester.     

Differential anti-lipid peroxidative activity of melatonin

Scavenging activities of melatonin, which is a pineal secretory product and functions in circadian biology, and its related compounds against reactive oxygen species such as superoxide anion radical, hydrogen peroxide, hydroxyl radical and singlet oxygen as well as organic peroxide radical (t-BuOO”) were evaluated chemically by using electron spin resonance-spin trap and chemiluminescence methods. Antioxidative activity of the compounds was estimated by IC₅₀ value (µM), 50% inhibiting concentration of a compound against reactive oxygen species formed in each system, and the second-order rate constants (k₂) for the reactions of the compounds and superoxide anion radical or hydroxyl radical. Because melatonin has exhibited the highest scavenging activity against t-BuOO”, the biochemical anti-lipid peroxide radical scavenging activities of melatonin were examined. We found that melatonin exhibits higher anti-lipid peroxidative activity in the rat brain microsomes than in the rat liver microsomal and liposomal systems, suggesting that melatonin may function as a treatment for reactive oxygen species-related diseases of the brain.     

Atmospheric Budget of Non-Seasalt Chlorine in the Kanto District,Japan

To evaluate the influence of anthropogenic emission of HCl on the air quality in the Kanto district of Japan, the atmospheric budgetof non-seasalt Cl (nssCl) was analyzed. The Kanto district, which consists of the Tokyo metropolis and the six surrounding prefectures, is the most densely populated region in Japan. The emission intensity of HCl is extremely high compared with those in other regions and most western countries. In this study, the annual wet and dry depositions of nssClwere estimated on a 0.25 × 0.25° grid over the Kanto district based on the concentration monitoring resultsand meteorological data. The budget analysis was conducted by comparing the estimated deposition with the emission of HCl. As a result, the annual total (wet + dry) deposition of nssCl was estimated to be 32 kt yr^-1, which closely agreed with HCl emission (36 kt yr^-1) from waste incineration in this area. The result suggested that the anthropogenic emission of HCl had a significant influence on the air quality and the deposition of acidity in this area.     

Ubiquity of parasporin-1 producers in <Emphasis Type="Italic">Bacillus thuringiensis</Emphasis> natural populations of Japan

Parasporin, a Bacillus thuringiensis parasporal protein, is unique in having a strong cytocidal activity preferential for human cancer cells. In this study, we characterized parasporin activities associated with three novel geographical isolates of B. thuringiensis. Parasporal inclusion proteins of the three isolates were highly toxic to human uterus cervix cancer cells (HeLa), but not to non-cancer uterine smooth muscle cells (UtSMC). Inclusions of the isolates lacked insect toxicity and hemolytic activity against sheep erythrocytes. Ouchterlony immunodiffusion tests revealed that the proteins of the three isolates are immunologically closely related to parasporin-1 (Cry31A), but dissimilar to the three other existing parasporin groups. Our results provide evidence that the parasporin-1-producing organism is a common member in B. thuringiensis populations occurring in natural environments of Japan.     

Soil characteristics under cash crop farming in upland areas of Sarawak,Malaysia

This study discusses soil fertility under perennial cash crop farming (para rubber, Hevea brasiliensis; black pepper, Piper nigrum; oil palm, Elaeis guineensis) conducted by local farmers and an oil palm estate in an upland area of Sarawak, Malaysia, in comparison with the surrounding secondary forests. In the farmlands of the local farmers, rubber farming was conducted without fertilizer application, while 2–5 t ha^?1 of NPK compounds were applied annually on pepper farms. Soils under rubber farming were acidic with poor nutrient contents, resembling soils in secondary forests. In pepper farms, soils were less acidic and showed high nutrient contents, especially with respect to available P and exchangeable Ca. This trend became stronger with increasing farming duration. Fertilizers applied around pepper vines appeared to migrate and spread across the fields. Bulk density and hardness of surface soils were higher in pepper farms than in secondary forests, indicating soil compaction due to field works. In the oil palm estate, annual fertilizer application rates were moderate at 0.4–0.8 t ha^?1 of NPK compound fertilizers. However, the soil properties in the oil palm estate were similar to those of the small-scale pepper farms. Close to the bases of the palms where fertilizers usually are applied, the contents of exchangeable Ca and available P were high. Nutrient uptake by the dense root systems of the palms seemed to prevent excessive loss of nutrients through leaching. Loss of soil organic matter and deterioration of soil physical properties were brought about by terrace bench construction, but the soils seemed to recover to some extent over time. In conclusion, technologies such as intercropping and the appropriate allocation of different crops to specific locations as well as the proper selection and dosage of fertilizers should be developed and adopted to improve fertilizer efficiency and prevent water pollution due to fertilizer wash-off from farmlands.     

Principal components derived from soil physicochemical data explained a land degradation gradient,and suggested the applicability of new indexes for estimation of soil productivity in the Sakaerat Environmental Research Station,Thailand

To find a principal component (PC) that quantifies the degree of soil degradation, we analyzed various physicochemical characteristics of soils over a land degradation gradient related to aboveground vegetation in the Sakacrat Environmental Research Station (SERS), Thailand. The aboveground vegetative types representing the degradation gradient were bare ground (BG, highly degraded), dry dipterocarp forest (DDF, moderately disturbed) and dry evergreen forest (DEF, the original vegetation). Soils under these vegetative types were sampled in February (dry season). March just after temporal precipitation) and June (rainy season) 2001. Through the period of this research, the degradation was consistently explained by sandy texture, high bulk density, lower pH, high exchangeable acidity, poor mineral and organic nutrients and dryness. Principal component analysis (PCA) was applied to determine significant principal components (PCs) that clarify the differences in soil properties between the vegetative types and between the timing of soil sampling. The PC loadings suggested that the first PC was the component that indicates total fertility of soil in the site, while the fifth PC indicates the dry to wet seasonal transition. The first PC was named the total fertility component (TFC). The linear regression between the TFC score and recently proposed indexes, the soil fertility index (SFI) or the soil evaluation factor (SEF), was highly significant (p < 0.001), indicating that the SFI and the SEF are applicable to measuring total fertility of soils in the SERS.