Estimate of Fukushima-derived radiocaesium in the North Pacific Ocean in summer 2012.

Distributions of radiocaesium (134Cs and 137Cs) derived from the Tokyo Electric Power Company (TEPCO) Fukushima Dai-ichi Nuclear Power Plant (FNPP1) accident in the North Pacific Ocean in the summer of 2012 were investigated. We have estimated the radiocaesium inventory in the surface layer using the optimal interpolation analysis and the subducted amount into the central mode water (CMW) by using vertical profiles of FNPP1-134Cs and mass balance analysis as the first approach. The inventory of the 134Cs in the surface layer in the North Pacific Ocean in August-December 2012 was estimated at 5.1 ± 0.9 PBq on 1 October 2012, which corresponds to 8.6 ± 1.5 PBq when it was decay corrected to the date of the FNPP1 accident, 11 March 2011. It was revealed that 56 ± 10% of the released 134Cs into the North Pacific Ocean, which was estimated at 15.3 ± 2.6 PBq, transported eastward in the surface layer in 2012. The amount of 134Cs subducted in the CMW was estimated to be 2.5 ± 0.9 PBq based on the mass balance among the three domains of the surface layer, subtropical mode water, and CMW.

The POSEIDON-R compartment model for the prediction of transport and fate of radionuclides in the marine environment.

A detailed description of the advanced version of compartment model POSEIDON-R for the prediction of transport and fate of radionuclides in the marine environment is given. The equations of transfer of radionuclides in the water and bottom sediment compartments along with the dynamical food chain model are presented together with dose module to assess individual and collective doses to the population due to the regular and accidental releases of radionuclides. The method for the numerical solution of model equations is also presented. The modelling results for the northeast Atlantic shelf seas were compared with measurements of 137Cs. •The three-dimensional compartment model POSEIDON-R describes the transfer of radionuclides and their daughter products in marine environment as a results of regular or accidental releases. This includes any transfer through the water column and sediments.•The model is complemented by a dynamic food chain model for transfer of radioactivity in pelagic and benthic food webs.•The dose module in the model calculates internal and external doses for humans and non-human biota.

Similarities and differences of 137Cs distributions in the marine environments of the Baltic and Black seas and off the Fukushima Dai-ichi nuclear power plant in model assessments.

The compartment model POSEIDON-R with an embedded food web model was used to assess 137Cs distributions in the Baltic and Black seas and off the Pacific coast of Japan during 1945-2020 due to the weapon testing and accidents at the Chernobyl and Fukushima Dai-ichi nuclear power plants. The results of simulations conducted with generic parameters agreed well with measurements of 137Cs concentrations in the water, bottom sediments, and in fish. In the Black and Baltic seas, salinity variations affected the transfer of 137Cs through the food web. The contamination of pelagic fish followed the water contamination with some delay, whereas demersal fish depuration was found to be related to decreasing 137Cs concentrations in the upper sediment layer. On the Pacific shelf off Japan, intensive currents and eddies caused the simulated depuration rates in fish to be one-two orders of magnitude larger than those in the semi-enclosed Black and Baltic seas.

Marine radioecology after the Fukushima Dai-ichi nuclear accident: Are we better positioned to understand the impact of radionuclides in marine ecosystems?

This paper focuses on how a community of researchers under the COMET (CO-ordination and iMplementation of a pan European projecT for radioecology) project has improved the capacity of marine radioecology to understand at the process level the behaviour of radionuclides in the marine environment, uptake by organisms and the resulting doses after the Fukushima Dai-ichi nuclear accident occurred in 2011. We present new radioecological understanding of the processes involved, such as the interaction of waterborne radionuclides with suspended particles and sediments or the biological uptake and turnover of radionuclides, which have been better quantified and mathematically described. We demonstrate that biokinetic models can better represent radionuclide transfer to biota in non-equilibrium situations, bringing more realism to predictions, especially when combining physical, chemical and biological interactions that occur in such an open and dynamic environment as the ocean. As a result, we are readier now than we were before the FDNPP accident in terms of having models that can be applied to dynamic situations. The paper concludes with our vision for marine radioecology as a fundamental research discipline and we present a strategy for our discipline at the European and international levels. The lessons learned are presented along with their possible applicability to assess/reduce the environmental consequences of future accidents to the marine environment and guidance for future research, as well as to assure the sustainability of marine radioecology. This guidance necessarily reflects on why and where further research funding is needed, signalling the way for future investigations.

Tracing radioactivity from Fukushima in the Northern Pacific Ocean.

Following the accident at the Fukushima Daiichi nuclear power plant, a campaign of sampling and measuring anthropogenic radionuclides in North Pacific seawater was set up. The main aim was to study natural processes using these radionuclides as tracers. Because of dilution, the activities of anthropogenic radionuclides at long range were very low and their measurement required advanced pre-concentration techniques and underground gamma-ray spectrometry. Data and metrological aspects of the measurements using HPGe-detectors are presented and discussed.

Spatial and temporal distributions of (134)Cs and (137)Cs derived from the TEPCO Fukushima Daiichi Nuclear Power Plant accident in the North Pacific Ocean by using optimal interpolation analysis.

Optimal interpolation (OI) analysis was used to investigate the oceanic distributions of (134)Cs and (137)Cs released from the Tokyo Electric Power Company Fukushima Daiichi Nuclear Power Plant (FNPP1) accident. From the end of March to early April 2011, extremely high activities were observed in the coastal surface seawater near the FNPP1. The high activities spread to a region near 165°E in the western North Pacific Ocean, with a latitudinal center of 40°N. Atmospheric deposition also caused high activities in the region between 180° and 130°W in the North Pacific Ocean. The inventory of FNPP1-released (134)Cs in the North Pacific Ocean was estimated to be 15.3 ± 2.6 PBq. About half of this activity (8.4 ± 2.6 PBq) was found in the coastal region near the FNPP1. After 6 April 2011, when major direct releases ceased, the FNPP1-released (134)Cs in the coastal region decreased exponentially with an apparent half-time of about 4.2 ± 0.5 days and declined to about 2 ± 0.4 PBq by the middle of May 2011. Taking into account that the (134)Cs/(137)Cs activity ratio was about 1 just after release and was extremely uniform during the first month after the accident, the amount of (137)Cs released by the FNPP1 accident increased the North Pacific inventory of (137)Cs due to bomb testing during the 1950s and early 1960s by 20%.

Biochemical and hematologic effects of polyvinylpyrrolidone-wrapped fullerene C60 after oral administration.

The fullerene C60 is used in consumer products such as cosmetics owing to its antioxidative effects and is being developed for nanomedical applications. However, knowledge regarding the safety of fullerene C60, especially after oral administration, is sparse. Here, we examined the safety of fullerene C60 in mice after 7 d of exposure to orally administered polyvinylpyrrolidone (PVP)-wrapped fullerene C60 (PVP-fullerene C60). Mice treated with PVP-fullerene C60 showed few changes in the plasma levels of various markers of kidney and liver injury and experienced no significant hematologic effects. Furthermore, the histology of the colon of PVP-fullerene C60-treated mice was indistinguishable from that of control mice. These results suggest that PVP-fullerene C60 lacks toxicity after high-dose oral administration and indicate that PVP-fullerene C60 can be considered safe for oral medication. These data provide basic information that likely will facilitate the production of safe and effective forms of fullerene C60.

Optimum interpolation analysis of basin-scale ¹³7Cs transport in surface seawater in the North Pacific Ocean.

¹³7Cs is one of the conservative tracers applied to the study of oceanic circulation processes on decadal time scales. To investigate the spatial distribution and the temporal variation of ¹³7Cs concentrations in surface seawater in the North Pacific Ocean after 1957, a technique for optimum interpolation (OI) was applied to understand the behaviour of ¹³7Cs that revealed the basin-scale circulation of Cs ¹³7Cs in surface seawater in the North Pacific Ocean: ¹³7Cs deposited in the western North Pacific Ocean from global fallout (late 1950s and early 1960s) and from local fallout (transported from the Bikini and Enewetak Atolls during the late 1950s) was further transported eastward with the Kuroshio and North Pacific Currents within several years of deposition and was accumulated in the eastern North Pacific Ocean until 1967. Subsequently, ¹³7Cs concentrations in the eastern North Pacific Ocean decreased due to southward transport. Less radioactively contaminated seawater was also transported northward, upstream of the North Equatorial Current in the western North Pacific Ocean in the 1970s, indicating seawater re-circulation in the North Pacific Gyre.

Region-specific expression of a water channel protein, aquaporin 4, on brain astrocytes.

Cellular activities within the brain display regional specificity and a neuronal and glia interdependence. Components characterizing the regional specificity of neurons have been identified. However, characterization of the astrocyte remains in question. To identify region specific features of astrocytes, we have characterized the molecular phenotype of cells derived from regions with different levels of neuronal excitability, the cortex and striatum. Astrocytes were identified in cryostat sections of adult rat brain by rapid immunostaining for glial fibrillary acidic protein (GFAP), and individual cells were collected from each region by using laser microdissection (LMD). Total RNA was isolated and subjected to DNA microarray analysis. At least eight genes showed a differential expression level. Among them, aquaporin 4 (AQP4), a water channel protein, was expressed at higher levels within the cortex compared with the striatum, as confirmed by immunohistochemistry. Primary cultured astrocytes isolated from rat cortex or striatum also showed a differential expression of AQP4. These data may reflect unique properties of astrocytes across different brain regions. However, they may also reflect the interactive demands of neurons with different activity levels. Further examination of the heterogeneous astrocyte populations within each region will lend additional support to the regional specificity of neuronal functions and neuronal-glial interactions.

Interleukin (IL)-1 and IL-6 regulation of neural progenitor cell proliferation with hippocampal injury: differential regulatory pathways in the subgranular zone (SGZ) of the adolescent and mature mouse brain.

Current data suggests an association between elevations in interleukin 1 (IL-1)α, IL-1ß, and IL-6 and the proliferation of neural progenitor cells (NPCs) following brain injury. A limited amount of work implicates changes in these pro-inflammatory responses with diminished NPC proliferation observed as a function of aging. In the current study, adolescent (21day-old) and 1year-old CD-1 male mice were injected with trimethyltin (TMT, 2.3mg/kg, i.p.) to produce acute apoptosis of hippocampal dentate granule cells. In this model, fewer 5-bromo-2'-deoxyuridine (BrdU)+ NPC were observed in both naive and injured adult hippocampus as compared to the corresponding number seen in adolescent mice. At 48h post-TMT, a similar level of neuronal death was observed across ages, yet activated ameboid microglia were observed in the adolescent and hypertrophic process-bearing microglia in the adult. IL-1α mRNA levels were elevated in the adolescent hippocampus; IL-6 mRNA levels were elevated in the adult. In subgranular zone (SGZ) isolated by laser-capture microdissection, IL-1ß was detected but not elevated by TMT, IL-1a was elevated at both ages, while IL-6 was elevated only in the adult. Naïve NPCs isolated from the hippocampus expressed transcripts for IL-1R1, IL-6Rα, and gp130 with significantly higher levels of IL-6Rα mRNA in the adult. In vitro, IL-1α (150pg/ml) stimulated proliferation of adolescent NPCs; IL-6 (10ng/ml) inhibited proliferation of adolescent and adult NPCs. Microarray analysis of SGZ post-TMT indicated a prominence of IL-1a/IL-1R1 signaling in the adolescent and IL-6/gp130 signaling in the adult.

Immunohistochemical localization of catecholamine biosynthetic enzymes in the adrenal gland of the domestic fowl (Gallus domesticus).

The present study investigated the cellular localization of 3 catecholamine biosynthetic enzymes, tyrosine hydroxylase (TH), dopamine beta-hydroxylase (DBH), and phenylethanolamine N-methyltransferase (PNMT) to identify and analyze the localization of norepinephrine (NE) and epinephrine (E) cells in the adrenal gland in the chicken using peroxidase-antiperoxidase immunohistochemical techniques. Tyrosine hydroxylase immunoreactivity (IR) was observed in almost all adrenal medullary cells of the adult chicken. Dopamine beta-hydroxylase IR coincided with that of TH. Many medullary cells also exhibited PNMT IR, but PNMT-immunonegative cells were also observed. Tyrosine hydroxylase IR was localized in the E- and NE-containing cells, but PNMT IR was localized only in the E-containing cells. Approximately 69% of medullary cells were E-containing, and the remaining were NE-containing cells. The ratio of E- and NE-containing cells between the subcapsular and central zone was statistically significant (P < 0.01). Although cortical cells of the adrenal gland did not show TH-, DBH-, or PNMT-positive reactions, ganglia close to the adrenal gland showed TH, DBH, and PNMT immunoreactivities. These findings indicated the cellular localization of 3 catecholamine-biosynthesizing enzymes in chicken adrenal medulla and suggest that the majority of medullary cell are E-containing cells. The ratio of E cells to NE cells varies among the 3 zones in the adrenal glands of the chicken.

Depositional behaviors of plutonium and thorium isotopes at Tsukuba and Mt. Haruna in Japan indicate the sources of atmospheric dust.

Monthly plutonium and thorium depositions at Tsukuba (28m asl) and Mt. Haruna (1370m asl) were measured during 2006 and 2007 (Jan 2006-Dec 2007 at Tsukuba, Nov 2006-Dec 2007 at Mt. Haruna). The monthly (239,240)Pu depositions ranged from 0.044 to 2.67mBq m(-2) at Tsukuba and from 0.05 to 0.9mBq m(-2) at Mt. Haruna during the measurement periods. Monthly (239,240)Pu deposition did not differ markedly between the two sites except in April 2007. Seasonal pattern of monthly (239,240)Pu depositions at both sites showed high in spring and low in summer, and typical of seasonal variations in northeastern Asia. Thorium deposition at Tsukuba was higher than that at Mt. Haruna except in May and June 2007. (230)Th/(232)Th activity ratios were used to partition deposition samples into locally and remotely derived fractions. The results revealed that a major proportion of total (239,240)Pu and Th deposits are derived from remote sources, especially in spring.

Controlling the phase matching conditions of optical parametric chirped-pulse amplification using partially deuterated KDP.

Using a partially deuterated KDP crystal for an optical parametric amplifier, we demonstrated ultrabroadband optical parametric chirped-pulse amplification of more than 250 nm bandwidth at a center wavelength of 1050 nm. We numerically show how to control the broadband phase matching conditions at different wavelengths to match center wavelengths of suitable broadband seed sources by adjusting the deuteration level in partially deuterated KDP.

Silicone-induced foreign-body reaction after first metatarsophalangeal joint arthroplasty for Jaccoud's arthropathy.

We report a case of Jaccoud's arthropathy with forefoot plantar callosity. The lesser toe metatarsal heads were resected and Swanson's double-stemmed flexible-hinge implant arthroplasty of the first metatarsophalangeal joint was performed. An osteolytic defect had formed around the implant after 2 years. Surgical revision comprised implant removal and synovectomy. Histology revealed a foreign-body reaction with birefringent material in multinucleated giant cells. Because the capsuloligamentous system is fragile in Jaccoud's arthropathy, we recommend resection arthroplasty or arthrodesis of the first MP joint as an initial operative approach.

Serum cytochrome c to indicate the extent of ongoing tumor cell death.

Despite the significant implication of apoptosis in tumorigenesis, there is no biomarker to assess the extent of ongoing apoptosis in vivo for hematological malignancies. We investigated the potential of serum cytochrome c (cyto-c) as a biomarker for apoptosis. Cyto-c and lactate dehydrogenase (LD) were released into the culture medium from apoptotic cells induced by tumor necrosis factor-related apoptosis-inducing ligand in a time-dependent manner in vitro, with different kinetic patterns. Only one-third of 153 patients with hematological malignancies showed high levels of serum cyto-c (>20 ng/ml). Although serum cyto-c level was roughly correlated to serum LD activity, their different kinetic patterns from serial measurements indicated that serum cyto-c rather than LD is a more sensitive indicator for tracking changes of tumor status. Furthermore, serum cyto-c level stratified patients with acute adult T-cell leukemia into favorable and unfavorable subgroups with 5-year survival rates of 67%vs. 11%. In conclusion, serum cyto-c may provide a fast real-time biomarker for tracking changes of tumor status involved in apoptotic cell death, but lacking disease or cell-type specificity.

Neuropeptides and their receptors of the protochordate, Ciona intestinalis: the evolutionary origin of vertebrate neuropeptides.

Ci-TK and Ci-TK-R are authentic tachykinin (TK) and TK receptor isolated from a protochordate, Ciona intestinalis. In this study, we investigated a novel function of TK as an enhancer of oocyte growth. Ci-TK-R is expressed specifically in the Ciona vitellogenic oocytes. Moreover, administration of Ci-TK to the Ciona ovary resulted in upregulation of gene expression and enzymatic activity of several proteases. Moreover, maturation of the Ciona oocytes from the vitellogenic stage to the post-vitellogenic stage was induced in the presence of Ci-TK, which was completely blocked by addition of protease inhibitors.

Functions of a GnRH receptor heterodimer of the ascidian, Ciona intestinalis.

Gonadotropin-releasing hormone (GnRH) is a ten-amino acid peptide hormone that plays pivotal roles in reproduction in vertebrates and octopus. Recently, six GnRH forms (t-GnRH-3-8) and four GnRH receptor subtypes (Ci-GnRHR-1-4) were identified in the protochordate, Ciona intestinalis. In this study, we show the functional modulation of Ci-GnRHR-1 via heterodimerization with the orphan receptor subtype, Ci-GnRHR-4. The dimerization between Ci-GnRHR-1 and R-4 was detected by co-immunoprecipitation and immunoblot analysis. Binding assays confirmed the binding of t-GnRHs to Ci-GnRHR-1 but not to R-4, and verified no alternation in ligand-binding affinity between Ci-GnRHR-1 homodimer and Ci-GnRHRI&4 heterodimer. The heterodimer was found to stimulate the elevation of intracellular calcium, time-extension of ERK phosphorylation, and up-regulation of cell proliferation, all in a ligand specific manner, compared with the Ci-GnRHR-1 homodimer. In combination, these results indicated that Ci-GnRHR-4 is not an inactive receptor, but a modulatory factor for Ci-GnRHR-1 in C. intestinalis.

Analysis of the 50-year records of the atmospheric deposition of long-lived radionuclides in Japan.

Long-lived anthropogenic radionuclides ((137)Cs, (90)Sr, and Pu isotopes) have been determined in monthly atmospheric deposition samples collected in Japan since 1956. The maximum annual deposition occurred in 1963 after the large-scale atmospheric nuclear weapons testing of 1961-1962. In the 1980s, the fallout from the Chinese nuclear weapons tests was observed and the released radionuclides from the Chernobyl accident affected radioactive deposition in Japan until the early 1990s. Recently, the deposition rates have been boosted by the resuspension of radionuclides in deposited particles, the (239,240)Pu content of which may originate from dusts from the East Asian continent deserts and arid areas.

High-energy, diode-pumped, picosecond Yb:YAG chirped-pulse regenerative amplifier for pumping optical parametric chirped-pulse amplification.

A diode-pumped, cryogenic-cooled Yb:YAG regenerative amplifier utilizing gain-narrowing has been developed. A 1.2-ns chirped-seed pulse was simultaneously amplified and compressed in the regenerative amplifier, which generated a 35-ps pulse with ~8-mJ of energy without a pulse compressor. Second-harmonics of the amplified pulse was used to pump picosecond two-color optical parametric amplification.