We propose a geochemical parameter, "metal flux" in evaluating hydrogenetic Co-rich ferromanganese crust deposits in the Pacific seamount area, that is based on physical, chemical, and geological ...characterization of the integrated growth piles of crusts. We calculated the metal flux for fifteen sites from different depths ranging between 900-6000m from different seamounts. The secular and areal variations of metal flux indicate a strong geological controls, and also can be a reliable tool for estimating an economic potential of the crusts. The Co flux decreases with increasing water depth, followed by almost constant flux of Ni and Mn. The Al and Fe fluxes vary with regions, indicating higher values in the western regions near the island arc probably related to a supply from the Asian continents. The results imply that Co, a redox sensitive metal element, is controlled by redox conditions of seawater, while Fe and Al are by terrigenous input. The metal flux reflects global and regional conditions and controls the compositional diversity of metals, thus consequently, the parameter can be a reliable powerful tool to estimate or single out more potential areas.
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BFBNIB, DOBA, GIS, IJS, IZUM, KILJ, KISLJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
The present study investigated whether exposure to aromas during recess periods affects work performance. Subjects comprised 36 healthy male students (mean age, 24.2 ± 2.2 years) who were randomly ...divided into three groups: (1) control group, not exposed to aroma during recesses; (2) jasmine group, exposed to jasmine aroma during recesses; and (3) lavender group, exposed to lavender aroma during recesses. All participants completed five work sessions performing a task requiring concentration on a computer monitor, with each session lasting 60 min. Recess periods of 30 min were provided between each session. To clarify the time at which work concentration was lowest, work performance for the control group was analyzed. Concentration was lowest in the afternoon period, where afternoon drowsiness is strongest. Comparison of the three groups for this time period indicated significantly higher concentration levels for the lavender group than for the control group. No such effect was noted for the jasmine group. Although lavender is a sedative-type aroma, use during recess periods after accumulation of fatigue seems to prevent deterioration of performance in subsequent work sessions.
The lateral pterygoid muscle has been generally described as a muscle composed of two separate heads, however, the border between these heads has not clearly identified. In the present study, we ...investigated the positional relationships between the muscle and the surrounding nerves, and examined the muscle bundle arrangements to determine the detailed information of the origins and insertions. We used 94 specimens of 52 Japanese cadavers (29 males and 25 females) for the investigations of the nerve courses, and randomly chose and used 10 specimens of 5 (2 males and 3 females) cadavers from above-mentioned 52 cadavers for the detailed examinations of the muscle fiber constructions. In some specimens, the buccal nerve passed through the gap in the muscle, however, in many cases the nerve pierced the muscle. The muscle inserted into the medial half of the anterior surface and the medial surface of the condylar process. Only a thin superficial layer of the muscle fibers was attached to the inferior surface of the articular disc. According to the positions of the origins and insertions of the muscle and the positional relationships to the nerves, the muscle was not clearly divided into heads. The detailed findings of the origins and insertions of the present study suggest that the muscle is a single muscle with no clear border, containing fibers of various directions. A two-head muscle pattern would be indicated by the differences of the convergences of the muscle fibers.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, VSZLJ, ZAGLJ
The growth of high-crystalline-quality GaN by hydride vapor phase epitaxy, focusing on dislocation density reduction, was studied, and a facet-initiated epitaxial lateral overgrowth (FIELO) method ...has been proposed. In this method, a GaN layer develops by the overgrowth of facet structures generated from narrow channels opened in a SiO2 mask formed on a GaN template. The threading dislocations changed their propagation direction, bending in the horizontal direction, due to the facet structure. To reduce the number of threading dislocations through the channels, we propose a novel FIELO method with nanometer-size channels. The dislocation density was found to decrease to 4.5 × 107 cm−2 for a 20-μm-thick GaN layer. We also developed random-island FIELO, in which micrometer-size small islands are initially formed on a TiC buffer layer by low-temperature growth of GaN on a sapphire substrate. Under higher growth temperatures that follow, the growth of these small islands changes to three-dimensional (3D) growth with facet planes. The 3D growth was maintained for a thickness of approximately 100-200 μm. As a result, the dislocation density was reduced to ∼3 × 106 cm−2. Freestanding 2- and 4-inch-diameter GaN substrates were also successfully fabricated by using the random-island FIELO method.
To validate the Japanese versions of the Ullanlinna Narcolepsy Scale (J-UNS) and Swiss Narcolepsy Scale (J-SNS) for screening narcolepsy in the Japanese population and to discuss strategies for their ...use in hypersomniac individuals.
We selected 451 outpatients with excessive daytime sleepiness (EDS) already diagnosed according to the International Classification of Sleep Disorders third edition. They responded to both scales twice at 1-month intervals. After eliminating individuals who met the exclusion criteria, validity and reliability analyses were performed on 408 and 381 participants, respectively.
Patients with narcolepsy type 1 (NT1) displayed higher J-UNS and lower J-SNS scores than those with NT2 and other sleep disorders. The intraclass correlation coefficients and weighted κ coefficient for scale scores in the total participants and patients with NT1 were ≥0.70 and ≥ 0.40, respectively, indicating high reliability. Furthermore, both the sensitivity and specificity of these scales upon using the original cut-off scores (14 for UNS and 0 for SNS) for detecting NT1 were 0.70 or ≥0.70, suggesting high validity. Additionally, the receiver operating characteristic curve analysis revealed that the best cut-off score did not change for the J-SNS but that for the J-UNS, it increased to 18. In our study, the scale's sensitivity and specificity changed from 96% to 82% and 58%–78%, respectively.
Both scales revealed satisfactory screening abilities for NT1 in the Japanese population. However, it may be better to use J-UNS cut-off scores of 18 for a population with EDS.
•We aimed to validate the Japanese versions of two narcolepsy scales.•The Japanese versions of these scales could detect narcolepsy type 1.•These scales will aid early diagnosis of narcolepsy in the Japanese population.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The oxidation state and mineral phase association of Co, Ce, and Pb in hydrogenetic, diagenetic, and hydrothermal marine ferromanganese oxides were characterized by X-ray absorption near-edge ...structure (XANES) and extended X-ray absorption fine structure (EXAFS) spectroscopy and chemical extraction. Cobalt is trivalent and associated exclusively with the Mn oxide component (vernadite). Cerium is tetravalent in all genetic-type oxides (detection limit for Ce(III)
∼
5 at. %), including Fe-rich areas (ferrihydrite) of hydrogenetic oxides, and is associated primarily with vernadite. Thus, the extent of a Ce anomaly does not result from variations in redox conditions, but appears to be kinetically controlled, decreasing when the growth rate increases from hydrogenetic to diagenetic to hydrothermal oxides. Lead is divalent and associated with Mn and Fe oxides in variable proportions. According to EXAFS data, Pb is mostly sorbed on edge sites at chain terminations in Fe oxide and at layer edges in Mn oxide (ES complex), and also on interlayer vacancy sites in Mn oxide (TCS complex). Sequential leaching experiments, spectroscopic data, and electrochemical considerations suggest that the geochemical partitioning in favor of the Mn oxide component decreases from Co to Ce to Pb, and depends on their oxidative scavenging by Mn and Fe oxides.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
The occurrence of 10Be in natural archives is commonly used to date their formation and growth on time scales of million years. Accelerator Mass Spectrometry (AMS) can perform a direct measurement of ...the 10Be/9Be ratio. The carrier-free method, in which no 9Be carrier is added to the original sample, is especially suitable for 10Be/9Be ratio determination in the marine environment. By normalizing the 10Be content to 9Be, temporal variations of Be uptake processes into the archive are eliminated.
Here, we present a simple method for the chemical extraction of beryllium from ferromanganese (FeMn) crusts or nodules, the measurement procedure, and the first carrier-free 10Be/9Be measurements at the 3 MV AMS facility VERA. Several tests of chemical methods are discussed including different options to short-cut and accelerate the procedure for special cases. Results from FeMn crust 237KD from cruise VA13/2 in the Pacific ocean show the known 10Be/9Be distribution with depth that is commonly related to a changing growth rate of the archive. In this context we discuss the potential influence of diffusion and adsorption processes on the age models of FeMn crusts that are based on radioactive nuclides such as 10Be and 230Th. Including an open-system behavior for these isotopes in the description of their profiles allows interpreting the accumulation of crusts with a constant growth rate over millions of years and does not require the assumption of abrupt growth changes.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Tellurium, an element of growing economic importance, is extremely enriched in marine ferromanganese oxides. We investigated the mechanism of this enrichment using a combination of spectroscopic ...analysis and adsorption/coprecipitation experiments. X-ray Absorption Near-Edge Structure (XANES) analysis showed that in adsorption/coprecipitation systems, Te(IV) was oxidized on δ-MnO2 and not oxidized on ferrihydrite. Extended X-ray Absorption Fine Structure (EXAFS) analysis showed that both Te(IV) and Te(VI) were adsorbed on the surface of δ-MnO2 and ferrihydrite via formation of inner-sphere complexes. In addition, Te(VI) can be structurally incorporated into the linkage of Fe octahedra through a coprecipitation process because of its molecular geometry that is similar to the Fe octahedron. The largest distribution coefficient obtained in the adsorption/coprecipitation experiments was for the Te(VI)/ferrihydrite coprecipitation system, and it was comparable to those calculated from the distribution between natural ferromanganese oxides and seawater. Our XAFS and micro-focused X-ray fluorescence (μ-XRF) mapping of natural ferromanganese oxides showed that Te was structurally incorporated as Te(VI) in Fe (oxyhydr)oxide phases. We conclude that the main process for the enrichment of Te in ferromanganese oxides is structural incorporation of Te(VI) into Fe (oxyhydr)oxide phases through coprecipitation.
This mechanism can explain the unique degree of enrichment of Te compared with other oxyanions, which are mainly enriched via adsorption on the surface of the solid structures. In particular, the great contrast in the distributions of Te and Se is caused by their oxidized species: (i) the similar geometry of the Te(VI) molecule to Fe octahedron, and (ii) quite soluble nature of Se(VI). Coexisting Mn oxide phases may promote structural incorporation of Te(VI) by oxidation of Te(IV), although the surface oxidation itself may not work as the critical enrichment process as in the case of some cations. This enrichment mechanism also means that ferromanganese oxides mainly scavenge dominant Te(VI) species from seawater and do not affect its species distribution in seawater, as described in a previous model. The variation in Te abundances and the correlation of Te concentration with the growth rate of natural ferromanganese oxides are consistent with the coprecipitation mechanism.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
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