Occurrence and sources of perfluorinated surfactants in rivers in Japan

We analyzed perfluorinated surfactants (PFSs) in 20 river samples and 5 wastewater secondary effluent samples in Japan to reveal their occurrence and sources. Nine PFS species were determined: perfluorooctanesulfonate (PFOS), perfluorooctane sulfonamide (FOSA), perfluoroheptanoate (PFHpA), perfluorooctanoate (PFOA), perfluorononanoate (PFNA), perfluorodecanoate (PFDA), perfluoroundecanoate (PFUA), perfluorododecanoate (PFDDA), and perfluorotridecanoate (PFTDA). PFSs were detected in all rivers, revealing nationwide contamination of rivers. In particular, 11 out of 20 river samples exceeded New Jersey guidance for PFOA in drinking water (40 ng/L). PFOS, PFHpA, PFOA, and PFNA were major species in Japan. Concentrations of PFOS, PFHpA, and PFNA in rivers were strongly correlated with population density, suggesting that the chemicals were derived from urban activities. PFOA showed a significant but weak correlation. We used crotamiton, a marker of sewage effluent, for further source analysis. Concentrations of PFOS, PFHpA, and PFNAwere strongly correlated with those of crotamiton, and plots of secondary effluents fell near the regression lines of rivers, indicating that the PFOS, PFHpA, and PFNA in rivers were derived from sewage effluent. On the other hand, PFOA was found at remarkably high levels (54-192 ng/L) in seven river samples containing low levels of crotamiton, suggesting that it was derived from nonsewage point sources, as well as sewage effluent. The total fluxes of sewage-derived PFOS, PFHpA, PFOA, and PFNA from Japan were estimated to be 3.6, 2.6, 5.6, and 2.6 t/year, respectively. This is the first report to identify PFOA in several rivers, derived from nonsewage point sources, by using a marker of sewage effluent.     

A monoarthritis model in rabbits induced by repeated intra-articular injections of lipopolysaccharide

In recent years, states have increasingly turned to managed care arrangements for financing and delivering health services to Medicaid beneficiaries. In 1996, approximately 40% of all Medicaid recipients were enrolled in some form of managed care. The rapid escalation of managed care in this population has been fueled by states' desire to slow the growth of Medicaid expenditures and by the trend toward managed care enrollment in the private health insurance industry. The effect of managed care on cost containment in the Medicaid program may be limited, however, because 85% to 90% of Medicaid managed care enrollees are women of childbearing age and children, who together account for 69% of Medicaid recipients, but only 26% of program costs. Nonetheless, the increase in managed care enrollment in this population may have a profound impact on health service delivery and health outcomes for U.S. children, approximately 20% of whom received health benefits through the Medicaid program in 1995. In the future, the proportion of Medicaid-eligible children enrolled in managed care will likely increase as a result of recent legislation that relaxed the requirement that states seek federal approval prior to mandating managed care enrollment for Medicaid beneficiaries. More states are relying on fully capitated arrangements as the preferred type of managed care for Medicaid recipients, despite the relative lack of experience many of these plans have in serving this low-income population. Moreover, managed care organizations have few incentives to enroll chronically or disabled children with higher-than-average expected costs. Without mechanisms in place that adequately adjust capitated rates to account for these higher-cost enrollees, managed care organizations may lose money, and children with the greatest health care needs may be underserved. As mandatory managed care enrollment for Medicaid recipients increases nationwide, states should carefully monitor changes in program costs and quality as well as implications for the delivery of pediatric health services and health outcomes.     

A subcloned human esophageal squamous cell carcinoma cell line with low thrombomodulin expression showed increased invasiveness compared with a high thrombomodulin-expressing clone--thrombomodulin as a possible candidate for an adhesion molecule of squamous cell carcinoma

Inside-out vesicles of plasma membranes prepared from a plant source were used as models to investigate effects of centrifugal forces on separations of early and late endosome populations by aqueous two-phase partition. Endosome subpopulations were resolved readily by preparative free-flow electrophoresis where acidification of the interiors of late endosomes occurred upon addition of ATP to activate a proton translocating ATPase. The resultant increased diffusion potential provided for a surface difference between late and early endosomes to permit electrophoretic separation. With the plant membranes, unincubated inside-out plasma membrane vesicles modeled early endosomes, whereas inside-out vesicles incubated with 1 mM ATP modeled late endosomes. A latent, 2,4-dichlorophenoxyacetic acid (2,4-D)-(auxin)-stimulated NADH:protein disulfide reductase measured spectrophotometrically was used as an enzymatic marker for both populations of inside-out vesicles. Phase partition behavior of each population was quantitated using total protein as the parameter.     

A new artificial life body: biologically inspired dynamic bipedal humanoid robots

Recently, a biologically inspired, bipedal, dynamic, humanoid robot was developed at the Artificial Life and Robotics Laboratory of Oita University. This bipedal humanoid robot is able to walk dynamically and to go up and down stairs. The central pattern generator developed produces various types of walking pattern. This robot has a pair of small CMOS color CCD cameras, a speaker, and a microphone in the head part, and will have a GPS, a portable telephone, and other sensors in the body part, so that the integration of locomotion and behavior to achieve specific demonstrations will be realized. This project develops dynamic mobility and the ability for autonomous recognition and navigation using the biological central nervous system, the brain system, and the real-time control system. Also, the design principles that demonstrate the dynamic interaction between neural and mechanical controls will be clarified. In Phase I, the platform of a small, bipedal, humanoid robot is used to develop autonomous locomotion and autonomous sensing and navigation. In Phase II of the project, an iteration on the platform design for human-size, bipedal, humanoid robots will be performed for operational testing. The development of bipedal humanoid robots that capture biological systems with unique principles and practices could dramatically increase their performance in tasks for national security needs.This work was presented in part at the 8th International Symposium on Artificial Life and Robotics, Oita, Japan, January 24–26, 2003     

Au/TiN/WSi-gate self-aligned GaAs MESFETs using rapid thermal annealing method

Au/TiN/WSi-gate self-aligned GaAs MESFETs were fabricated using the rapid thermal annealing method to reduce the gate resistance of the FETs. The gate resistance Rg was 4.2 ? (Lg=1.5 ?m, Wg=400 ?m), just 1/20 of that of the WSi-gate FET. The maximum frequency of oscillation fmax of the Au/TiN/WSi-gate FETs was improved to be about twice that of WSi-gate FETs.     

Correlation of temperature rise and velocity along an inclined fire plume axis in crosswinds

Experiments with a single fire source were carried out in crosswinds in order to elucidate the correlation between temperature rise and velocity along an inclined fire plume axis. A circular propane burner with a diameter of 0.2 m was used as a model fire source. The temperature and velocity were measured along the inclined fire plume axis, and these were compared with fire plume data obtained in a calm condition. An empirical formula to represent the correlation of the temperature rise and velocity was developed. The values of empirical coefficients and exponents were derived from the experimental results of the circular burner. In order to verify the availability of the proposed empirical formula, the comparison was carried out with the data obtained from square and/or rectangular burners.     

Structurally Diverse Polyamines: Solid‐Phase Synthesis and Interaction with DNA

A versatile solid‐phase approach based on peptide chemistry was used to construct four classes of structurally diverse polyamines with modified backbones: linear, partially constrained, branched, and cyclic. Their effects on DNA duplex stability and structure were examined. The polyamines showed distinct activities, thus highlighting the importance of polyamine backbone structure. Interestingly, the rank order of polyamine ability for DNA compaction was different to that for their effects on circular dichroism and melting temperature, thus indicating that these polyamines have distinct effects on secondary and higher‐order structures of DNA.