Depression of brain dopamine and its metabolite after mating in European honeybee (Apis mellifera) queens

To explore neuro-endocrinal changes in the brain of European honeybee (Apis mellifera) queens before and after mating, we measured the amount of several biogenic amines, including dopamine and its metabolite in the brain of 6- and 12-day-old virgins and 12-day-old mated queens. Twelve-day-old mated queens showed significantly lower amounts of dopamine and its metabolite (N-acetyldopamine) than both 6- and 12-day-old virgin queens, whereas significant differences in the amounts of these amines were not detected between 6- and 12-day-old virgin queens. These results are explained by down-regulation of both synthesis and secretion of brain dopamine after mating. It is speculated that higher amounts of brain dopamine in virgin queens might be involved in activation of ovarian follicles arrested in previtellogenic stages, as well as regulation of their characteristic behaviors.     

Magnetic resonance image findings of placental lake: report of two cases

Two cases with a large cystic mass within the placenta are reported. By ultrasonography, it was found that both women had a subchorionic hypoechoic lesion (11.0 × 4.8 × 4.0 cm and 6.6 × 3.7 × 2.2 cm, respectively) at 24 and 35 weeks of gestation, respectively. In both cases, turbulent blood flow generated by a pulsatile jet flow (pulse rate; 40 to 60 beats per minute) into the cystic lesion seen on real-time imaging and lesions being low intensity on T1-weighted and isointensity on T2-weighted magnetic resonance image suggested that they contained fresh maternal blood. In both cases, the sonolucency of the lesions did not change until cesarean deliveries of females, both of whom were small-for-gestational-age infants (1940 g at 37 weeks and 2195 g at 37 weeks, respectively). Biochemical analysis of the fluid in the cystic lesion sampled during the cesarean section in the latter case confirmed that the fluid had originated from the maternal blood. These lesions histologically corresponded to large avillous areas surrounded by normal villi. Thus, a huge placental lake was diagnosed in both cases. Copyright © 2005 John Wiley & Sons, Ltd.     

Lead contamination in surface soil on roads from used lead–acid battery recycling in Dong Mai,Northern Vietnam

Used lead–acid battery (ULAB) recycling has caused numerous health and environmental issues in developing countries. Surface soil pollution from ULAB recycling activities has been linked with elevated levels of lead in human blood. We measured surface soil lead in and surrounding the ULAB recycling village of Hung Yen in northern Vietnam in 2011, 2013, and 2014. The data were analyzed statistically and discussed with respect to distance from the contamination source, year of measurement, contamination pathway, and countermeasures against the contamination. Transportation routes from the smelter or collection site displayed the greatest concentration of surface soil lead (median 6400–10,000 mg/kg). Surface soil lead decreased significantly with distance along the road from the ULAB recycling site, although such a decrease was not observed for rice fields, agricultural roads, or garden soil. Re-suspension and adherence by traffic were identified as key pollution pathways. Distance from the source, covering of the surface of roads, construction of walls, and position relative to the source were shown to be the most effective factors in the reduction of surface soil lead pollution. Application of a combination of these measures should result in improvement in the health of residents.     

Photosynthetic and growth responses of Japanese sasabamo (Potamogeton wrightii Morong) under different photoperiods and nutrient conditions

Controlled laboratory experiments were conducted to examine how photosynthesis and growth occur in Potamogeton wrightii Morong under different photoperiods and nutrient conditions. The experiment was based on a 3×2 factorial design with three photoperiods (16, 12 and 8 h) of 200 μE · m^?2·s^?1 irradiance and two nutrient conditions, high (90 μmol N · L^?1·d^?1 and 9 μmol P · L^?1·d^?1) and low (30 μmol N L^?1·d^?1 and 3 μmol P · L^?1·d^?1). After 14, 28, 56 and 70 days of growth, plants were harvested to determine net photosynthesis rate and various growth parameters. Above- and below-ground biomass were investigated on days 56 and 70 only. Plants under low nutrient conditions had greater leaf area, more chlorophyll a, a higher rate of net photosynthesis and accumulated more above- and below-ground biomass than plants in the high nutrient condition. Plants with an 8 h photoperiod in the low nutrient condition had a significantly higher rate of net photosynthesis, whereas 8 h photoperiod plants in the high nutrient condition had a lower rate of net photosynthesis and their photosynthetic capacity collapsed on day 70. We conclude that P. wrightii has the photosynthetic plasticity to overcome the effects of a shorter photoperiod under a tolerable nutrient state.     

Air pollution and young children's inhalation exposure to organophosphorus pesticide in an agricultural community in Japan

Assessment of airborne organophosphorus pesticides in houses of young children (1-6 years old) and childcare facilities was conducted following pesticide applications in an agricultural community in Japan. Trichlorfon and fenitrothion, applied in two separate periods, were frequently detected from outdoor and indoor air. Dichlorvos, the primary degradation product of trichlorfon, was also detected after the application of trichlorfon. Both the outdoors and indoor concentration of applied pesticide were shown to increase with decreasing distance from the pesticide-applied farm. Indoor concentration of these pesticides significantly correlated with outdoor concentration (p=0.001 for trichlorfon and p=0.001 for fenitrothion), indicating infiltration of applied pesticide inside. Ratio of indoor to outdoor concentration (I/O ratio) of fenitrothion was higher for houses with windows open during the application than those with closed windows (median value: 0.74 vs. 0.16, p=0.003). However, a similar trend was not observed for trichlorfon as well as dichlorvos in the first period. Dichlorvos was found to have a higher I/O ratio than trichlorfon during the period, and clear correlation between indoor concentrations of dichlorvos and those of trichlorfon suggested increased decomposition of trichlorfon in the indoor environment. Daily inhalation exposure estimated by using the fixed measurement data and time-activity questionnaire ranged from 0 to 35 ng/kg/day for trichlorfon, from 0 to 26 ng/kg/day for dichlorvos, and from 0 to 44 ng/kg/day for fenitrothion. Median inhalation exposure from indoor air accounted for 74%, 86.3%, and 45% of the daily inhalation exposure, respectively. For kindergarteners or nursery school children, inhalation exposure at childcare facilities was comparable with or more than that at home, indicating that pollution level at childcare facilities had potential of high impact on children's exposure. Estimated daily inhalation exposures were inversely correlated to the proximity of their activity location to the pesticide-applied farm.     

Comparison of marginal abatement cost curves for 2020 and 2030: longer perspectives for effective global GHG emission reductions

This study focuses on analyses of greenhouse gas (GHG) emission reductions, from the perspective of interrelationships among time points and countries, in order to seek effective reductions. We assessed GHG emission reduction potentials and costs in 2020 and 2030 by country and sector, using a GHG emission reduction-assessment model of high resolution regarding region and technology, and of high consistency with intertemporal, interregional, and intersectoral relationships. Global GHG emission reduction potentials relative to baseline emissions in 2020 are 8.4, 14.7, and 18.9 GtCO₂eq. at costs below 20, 50, and 100 $/tCO₂eq., corresponding to +19, −2, and −7 %, respectively, relative to 2005. The emission reduction potential for 2030 is greater than that for 2020, mainly because many energy supply and energy-intensive technologies have long lifetimes and more of the current key facilities will be extant in 2020 than in 2030. The emission reduction potentials in 2030 are 12.6, 22.0, and 26.6 GtCO₂eq. at costs below 20, 50, and 100 $/tCO₂eq., corresponding to +19, −2, and −7 %, respectively, relative to 2005. The emission reduction potential for 2030 is greater than that for 2020, mainly because many energy supply and energy-intensive technologies have long lifetimes and more of the current key facilities will be extant in 2020 than in 2030. The emission reduction potentials in 2030 are 12.6, 22.0, and 26.6 GtCO₂eq. at costs below 20, 50, and 100 /tCO₂eq., corresponding to +33, +8, and −3 %, respectively, relative to 2005. Global emission reduction potentials at a cost below 50 $/tCO₂eq. for nuclear power and carbon capture and storage are 2.3 and 2.2 GtCO₂eq., respectively, relative to baseline emissions in 2030. Longer-term perspectives on GHG emission reductions toward 2030 will yield more cost-effective reduction scenarios for 2020 as well.     

Anthropogenic radionuclides in sediment in the Japan Sea: distribution and transport processes of particulate radionuclides

Distributions of anthropogenic radionuclides ((90)Sr, (137)Cs and (239+240)Pu) in seabed sediment in the Japan Sea were collected during the period 1998-2002. Concentration of (90)Sr, (137)Cs and (239+240)Pu in seabed sediment was 0.07-1.6 Bq kg(-1), 0.4-9.1 Bq kg(-1) and 0.002-1.9 Bq kg(-1), respectively. In the northern basin of the sea (Japan Basin), (239+240)Pu/(137)Cs ratios in seabed sediment were higher and their variation was smaller compared to that in the southeastern regions of the sea. The higher (239+240)Pu/(137)Cs ratios throughout the Japan Basin were considered to reflect production of Pu-enriched particles in the surface layer and substantial sinking of particulate materials in this region. In the southern regions of the Japan Sea (<38 degrees N), both inventories and (239+240)Pu/(137)Cs ratios in sediment were larger than those in the other regions. In the southern Japan Sea, observations suggested that supply of particulate radionuclides by the Tsushima Warm Current mainly enhanced accumulation of the radionuclides in this region.     

Estimation of 14CO2 flux at soil-atmosphere interface and distribution of 14C in forest ecosystem

To realize the dynamical behavior of 14C among exchangeable carbon reservoirs in terrestrial environment, a method for in situ determination of 14CO2 flux at soil-atmosphere interface and a high flow rate CO2 sampler were developed. This method allowed us to collect integrated quantity of CO2 for determining 14C activity over an extended time period under environmental conditions with minimal site disturbance. The 14CO2 flux from ground surface was estimated to be 1.59 x 10(-5) Bq m (-2) S (-1) in a forest floor with the method. The specific activities of 14C in environmental materials such as some biological and air samples were also determined in the vicinity of the place, where the flux measurement was made, to discuss the behavior of 14C in the forest ecosystem. The results indicated that fresh pine needles had a similar 14C specific activity to the atmospheric CO2 at the same height due to its fairly rapid equilibrium, 14C specific activity in the atmospheric CO2 has a concentration gradient near the ground surface and, at least in this site, CO2 with high 14C specific activity was generated by decomposition of soil organic matter which may be accumulated in soil as a result of former nuclear weapons tests.