Overexpression of NADH oxidase gene from Deinococcus geothermalis in Escherichia coli

When using stable enzyme genes from a thermophile to create a biosensor in Escherichia coli, it is vital that these genes be overexpressed in order to provide a sufficient supply of enzymes. In this study, overexpression of the NADH oxidase (Nox) gene from the thermophile Deinococcus geothermalis was successfully achieved with the aim of creating a stable biosensor active at room temperatures. To do so, modification of 10 nucleotides, GAAATTAACT, upstream of the start codon of the Nox gene was necessary.     

Overexpression of NADH oxidase gene from Deinococcus geothermalis in Escherichia coli

When using stable enzyme genes from a thermophile to create a biosensor in Escherichia coli, it is vital that these genes be overexpressed in order to provide a sufficient supply of enzymes. In this study, overexpression of the NADH oxidase (Nox) gene from the thermophile Deinococcus geothermalis was successfully achieved with the aim of creating a stable biosensor active at room temperatures. To do so, modification of 10 nucleotides, GAAATTAACT, upstream of the start codon of the Nox gene was necessary.     

Wayfinding with a GPS-based mobile navigation system: A comparison with maps and direct experience

This study examined the effectiveness of a Global Positioning System (GPS)-based mobile navigation system in comparison to paper maps and direct experience of routes, by focusing on the user's wayfinding behavior and acquired spatial knowledge. Based on information received from one of these three media, participants walked six routes finding the way to goals. Results showed that GPS users traveled longer distances and made more stops during the walk than map users and direct-experience participants. Also, GPS users traveled more slowly, made larger direction errors, drew sketch maps with poorer topological accuracy, and rated wayfinding tasks as more difficult than direct-experience participants. Characteristics of navigation with these three learning media and possible reasons for the ineffectiveness of the GPS-based navigation system are discussed.     

Destruction of polychlorinated naphthalenes by a high-temperature melting treatment (GeoMelt process)

A series of treatment experiments were carried out to evaluate the applicability of a high-temperature melting treatment (GeoMelt process) to the destruction of polychlorinated naphthalene (PCN) formulation. We started with 10-kg-scale experiments in which a small melting furnace was used and then scaled up to a 1-t-scale experiment in which a melting furnace that resembled an actual treatment system was used. These runs were evaluated whether destruction efficiency (DE) of total PCNs was more than 99.999 % and whether concentrations of PCNs and polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDDs/DFs) in vitrified materials, emission gas, and scrubber water were below the target levels. Because DE values and the target levels of PCNs and PCDDs/DFs in these runs were satisfactory, then we carried out a demonstrative experiment using the actual treatment system and confirmed destruction of PCNs. Based on good results of the demonstrative experiment, stock of PCN formulation was successfully treated continuously.     

Indoor/Outdoor Measurements of Volatile Organic Compounds in the Kanawha Valley of West Virginia

The Kanawha Valley region of West Virginia which is comprised of Charleston and surrounding communities Is the center of a heavily industrialized area known for its chemical manufacturing. As part of a larger study designed to investigate the Impact of the chemical industry on human exposures to volatile organic compounds (VOC), a study of the relationship between indoor and outdoor concentrations was conducted. Thirty-five homes were selected for monitoring from among volunteers; approximately ten in each of three distinct population-industry centers and four outside the Valley to act as controls. Monitoring was performed using passive, badge samplers with a three-week monitoring period. Two separate questionnaires were administered: one for characterization of the residence; and one to characterize source use during monitoring. Participants were also asked to keep a record of their activities with respect to in-home, outdoors and other Indoor environments. Analysis of the samplers was performed by solvent extraction followed by gas chromatography using a flame-ionization detector. Results suggest that indoor VOC concentrations are higher than outdoor concentrations. Additionally, certain ventilation-related parameters were identified that afforded some predictive power for indoor concentrations. No statistically significant differences between regions were identified.     

Respiratory tract retention of inhaled air pollutants: Report 1 : Mercury absorption by inhaling through the nose and expiring through the mouth at various concentrations

To study atmospheric mercury absorption in human respiratory passage-ways, mercury in expired air was measured in three different states of breathing: steady breathing, deep breathing and breath held after inspiration.In this study, air containing mercury was inhaled through the nose and expired through the mouth. The concentration of mercury in the exhaled air was determined by the technique of gold-amalgam trapping, heat vaporization, and flameless atomic absorption measurement.The subjects were 13 male adults, aged 25–62 years, and 38 cases were observed. Four different concentrations of mercury, 1–3, 4–6, 10–11, and 20–30 μg/m³ were used, and absorption for each was determined. When the concentration was 1–3 μg/m₃, the absorption was 74–92%, the average being 82.5%. At concentrations of 4–6, 10–11, and 20–30 μg/m₃, the absorption was 76.6–100%, 75.5–99.2%, and 79.9–95.9% respectively, and the average was 88.8%, 85.2%, and 87.7% respectively.A slightly higher rate of mercury absorption was observed in deep breathing than in steady breathing, and when expiration was suppressed for some time after inspiration, the rate increased remarkably to 97.4–99.7%. Prolonged retention of inhaled air containing mercury in the respiratory tract is believed to have caused the increased absorption.     

Tree-ring strontium-90 and cesium-137 as potential indicators of radioactive pollution

To examine whether tree rings can be used to detect or assess local historical 90Sr or 137Cs fallout, such as that resulting from the Hiroshima atomic bomb, radial distribution of 90Sr and 137Cs in trees was examined. We studied a gymnosperm [Japanese cedar, Cryptomeria japonica (L. f.) D. Don] and an angiosperm (Japanese persimmon, Diospyros kaki Thunb.) tree species from the vicinity of the atomic bomb hypocenter, and from other locations in Japan. A significant amount of 137Cs was detected in tree rings formed before 1945, indicating lateral migration of Cs. In contrast, the specific activity of 90Sr in the Hiroshima Japanese cedar showed the highest level in 1945, due to relatively immobile characteristics of Sr compared with Cs. Strontium-90 and Sr analyses in tree rings helped identify and distinguish between residual 90Sr activity from the Hiroshima atomic bomb and the atmospheric nuclear testing. This indicates the possibility of detecting or assessing previous local 90Sr pollution through with treering analysis.     

Photodegradation of tetraphenyltin contained in polychlorinated biphenyl-based transformer oil simulants in alkaline 2-propanol solution

The photodegradation of tetraphenyltin (TePT) contained in polychlorinated biphenyl (PCB)-based transformer oil simulants by ultraviolet (UV) irradiation in alkaline 2-propanol solutions was examined. In the absence of PCBs, the TePT level fell to below 1% of the initial concentration within 30 min. In the absence of both PCBs and an alkali, the concentrations of tri-, di-, and monophenyltins initially increased to a few milligrams per liter, and then reduced to below the detection limits within 90 min. The addition of an alkali to the reaction solution slightly accelerated the photodecomposition of TePT. The decomposition of other phenyltins (PTs) was also accelerated. When PCBs with concentrations of approximately 80 times the initial TePT concentration were added, only a small fraction of the TePT decomposed within 100 min. Moreover, the levels of PTs did not change during irradiation. TePT and other PTs did decompose when the level of PCBs was reduced to the same concentration as that of TePT; however, the decomposition rates were slower than those in the absence of PCBs. In the actual treatment process, TePT and other PTs in PCB-based transformer oil are decomposed by catalytic reduction, which is used after UV irradiation. Therefore, in the actual treatment of PCB-based transformer oil wastes, pollution due to PTs can be prevented.     

Early life history of tropical Anguilla leptocephali in the western Pacific Ocean

In order to examine the early life-history characteristics of tropical eels, otolith microstructure and microchemistry were examined in leptocephali of Anguilla bicolor pacifica (27.6-54.1 mm TL, n=20) and A. marmorata (22.0-47.3 mm TL, n=8) collected during a cruise in the western Pacific. A. bicolor pacifica occurred between 10°N and 15°N in the west and between 5°S and 10°N farther to the east. A. marmorata also occurred in two different latitudinal ranges in the Northern (15-16°N) and Southern Hemispheres (3-15°S) of the western Pacific. The increment widths in the otoliths of these leptocephali increased between the hatch check (0 days) and about an age of 30 days in both species, and then gradually decreased toward the otolith edge. Otolith Sr:Ca ratios showed a gradual increase from the otolith center to the edge. The ages of A. bicolor pacifica and A. marmorata leptocephali ranged from 40 to 128 days and from 38 to 99 days, respectively. Growth rates of A. bicolor pacifica and A. marmorata leptocephali ranged from 0.33 to 0.71 mm day^-1 and from 0.45 to 0.63 mm day^-1, respectively. These leptocephali had estimated growth rates that were spread out throughout most of the reported range of growth rates of the leptocephali of the temperate species, the Japanese eel and the Atlantic eels. Differences in the spatial distribution in relation to current systems, and the age and size compositions of the leptocephali of A. bicolor pacifica and A. marmorata suggested different spawning locations for these two species.     

Heritable pheromone blend variation in a local population of the butterbur borer moth Ostrinia zaguliaevi (Lepidoptera: Crambidae)

Summary. In a local population of Ostrinia zaguliaevi Mutuura & Munroe (Lepidoptera: Crambidae), extensive variation was found in the blend ratio of three sex pheromone components, (Z)-9-tetradecenyl acetate (Z9-14:OAc, 10.2-63.8%), (Z)-11-tetradecenyl acetate (Z11-14:OAc, 32.2-86.8%), and (E)-11-tetradecenyl acetate (E11-14:OAc, 2.1-11.9%). The variation was observed over a three-year period (2002-2004). Mother-daughter regression analyses have shown that although the heritability of the minor component E11-14:OAc was not significant, the heritability of the proportions of Z9-14:OAc and Z11-14:OAc were substantial (0.5–0.6). In artificial selection experiments, the mean % Z9-14:OAc in the sex pheromone changed significantly within three generations (37% in the control line, 48 and 52% for two lines selected for increase, and 23 and 30% for two lines selected for decrease). Despite these changes, the amounts of fatty acyl pheromone precursors, (Z)-9-, (Z)-11- and (E)-11-tetradecenoate, in the pheromone gland were not significantly affected by the selection. Taken together, variation in the pheromone blend of O. zaguliaevi is likely to be attributable to a few genes involved in the reduction or acetylation of fatty acyl pheromone precursors, the last two steps in pheromone biosynthesis.