The seasonal dynamics and the net growth rates of the planktonic freshwater cyanobacterium Cylindrospermopsis raciborskii were monitored in a shallow artificial pond in northern Taiwan from February 2010 to January 2011. C. raciborskii was present in the pond throughout the study, and its abundance was positively correlated with water temperature. The net growth rates of C. raciborskii displayed no clear seasonal pattern, whereas the highest value (0.184 d⁻¹) was observed in early July when the water temperature sharply increased to the annual highest level. The rapid growth of C. raciborskii led to bloom formation, which persisted over the summer months (July and August). Dilution and washout of trichomes by rainfall significantly affected the dynamics of C. raciborskii, including leading to the termination of a bloom.

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The validity of the assumption that the specific growth rate of coccoid microorganisms can be expressed as the absolute value of the derivative of frequency of dividing cells (FDC) with respect to time was tested experimentally using a Microcystis aeruginosa strain. FDC was calculated based on the assumption that elongated cells, constricted cells or both may correspond to dividing cells. The specific growth rates that were calculated from the diel in FDC were compared with those calculated from the change in the cell density. The results revealed that constricted cells can serve as the optimal dividing cells, and the calculated specific growth rates were statistically identical to those obtained by the change in the cell density.

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Sonication has been used in many studies that require observation of the cells of Microcystis aeruginosa. This study investigates the extent to which sonication (42 kHz, 150 W) destroys live and Lugol-fixed cells of M. aeruginosa, using two strains (NIES-1090 and NIES-1157). Live cells were easily destroyed by sonication regardless of growth stage. Sonication for 50 s caused up to 32.8% (NIES-1090) and 40.8% (NIES-1157) cell losses, and extended sonication (250 s) destroyed more cells. In contrast, sonication did not cause loss of cells that had been fixed with Lugol’s iodine solution. Interestingly, sonication often resulted in slightly higher counts of Lugol-fixed cells under a microscope. Sedimentation of Lugol-fixed cells is enhanced after sonication owing to the collapse of gas vacuoles and this appeared to facilitate reliable microscopic observations.

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Despite its phylogenetic importance, Thalassiosira lindstroemii has received little attention to date. In this study, the morphology of T. lindstroemii was examined in detail from upper Pliocene sediments of the subpolar North Atlantic. The valve has a valve face with linear areolation and scattered fultoportulae, a valve face/mantle junction with a single rimoportula and spines developed from triangular bases, and a mantle area with marginal fultoportulae and ribs. Both the valvocopula and second copula possess a characteristic ring of poroid areolae arranged along the advalvar margin. There is no doubt that T. lindstroemii is closely related to T. eccentrica, a major Thalassiosira species, because they possess many common morphological characteristics. Distinct differences between the two species include only the valve face areolation and the position of poroid areolae in the valvocopula. Although additional research is needed to reveal the precise phylogenetic relationship, the close morphological similarities suggest that T. lindstroemii is an ancestral (or possibly descendant) species of T. eccentrica.

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A new diatom species, Thalassiosira hexagona sp. nov., is described from lowermost Pleistocene sediments in the subpolar North Atlantic. The new species is morphologically characterized by linear striae, a ring of six evenly spaced subcentral fultoportulae, a single ring of marginal fultoportulae, spines fused with external tubes of the marginal fultoportulae, and a shallow mantle area with ribs. The new species is readily identified under scanning electron microscope observation because both the hexagonal ring of subcentral fultoportulae and the spines fused with external tubes of marginal fultoportulae are species-specific characteristics. However, the new species may have been misidentified as other centric diatom species with linear striae in previous studies because the species-specific characteristics are difficult to identify under light microscope observation. Among the known species, T. anguste-lineata is the morphologically most similar species to T. hexagona because both species exhibit linear striae and a ring of subcentral fultoportulae. However, all species with a ring of subcentral fultoportulae, except T. hexagona, display intraspecific

in the valve face striation pattern and the number of subcentral fultoportulae. The in the shape of the ring of subcentral fultoportulae and the in the valve face striation may be related to each other. Thalassiosira hexagona also resembles species in the genus Planktoniella in the presence of two rimoportulae and mantle ribs. A recent molecular phylogenetic study suggested that T. anguste-lineata, the species most similar to T. hexagona, belongs to a clade that is sister to Planktoniella species. Thus, in future it may be necessary to transfer T. hexagona and T. anguste-lineata to another genus.

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Thalassionema bacillare, which is a temperate and warm-water species in modern oceans, was recently revealed to have been one of the major diatom species in the subpolar North Atlantic around the Pliocene–Pleistocene boundary. In this study, the morphology of T. bacillare was examined through detailed observation of fossils collected from upper Pliocene to lower Pleistocene sediments in the subpolar North Atlantic. Although many morphological characteristics of the fossil valves examined in this study are consistent with results from previous studies of modern specimens of T. bacillare, there are some new important findings. For example, the fossil valves often have apical pores and lack spines on the tapered apex, though this is likely related to the weak silicification of the examined fossil valves. In addition, the minimum valve length is much shorter than previously reported, and external openings of rimoportulae differ slightly in shape between both poles. Fossils of T. bacillare are potential proxies for reconstructing paleoceanographic conditions because of the species’ limited modern distribution.

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A fossil nonmarine Actinocyclus species, A. krebsii sp. nov., is described from a lower to middle Miocene diatomite in the Chojabaru Formation, Nagasaki Prefecture, western Japan. The new species is characterized by having a valve face with concentric undulation, a shallow mantle, non- or vaguely fasciculate areolae, hyaline stripes extending from the valve face to the mantle, rimoportulae born from distal ends of the hyaline stripes, and a single pseudonodulus. Size-dependent variations are concentric undulation, the development of internal labia of rimoportulae, and the number of hyaline stripes and rimoportulae. Size-independent variations occur at the valve face/mantle junction: external expression of a hyaline area and internal expression of the pseudonodulus. Among nonmarine species of Actinocyclus, A. krebsii belongs to the non-fasciculate group that is characterized by having relatively few large and closely packed (low density) areolae on the valve face. Within this group, A. krebsii is most similar to A. venenosus because they both have long hyaline stripes that extend from the valve face to the mantle. Actinocyclus krebsii, however, has a higher density of areolae on the valve face and longer hyaline stripes than A. venenosus. Additionally, A. krebsii does not have the well-developed hyaline valve/mantle junction and spines that characterize A. venenosus.

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Using Ig-β and growth hormone producing cells with liver-derived cells for controls, sensitivity of chromatin to DNase I was measured by real-time PCR at eleven targets in rat Ig-β/growth hormone locus where four cell type-specific genes and two ubiquitously expressed genes are present in a compact 88-kb region. Chromatin situated at the promoter of actively-transcribed gene and placed at cell type-specific DNase I hypersensitive sites with enhancer activity was sensitive to DNase I. In the case of inactive gene, chromatin located in these regions was resistant to DNase I. Unexpectedly, however, chromatin placed in the transcribed intron was resistant to DNase I in two genes. DNase I sensitive chromatin was shown not to distribute locus-widely but rather to localize at the promoter and the enhancer of actively-transcribed genes in this locus.

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We investigated the temporal evolution of two types of diagram produced by a three-dimensional large-eddy simulation: the Contoured Frequency Optical Depth Diagram (CFODD) and the correlation pattern between the cloud droplet effective radius and the cloud optical thickness (RE-COT pattern). The CFODD obtained by statistically method, in the past study, suggested that the transition of cloud stages were included in the diagram, but this paper is the first paper that confirms similar structure in the CFODD obtained by time-series analysis. Our results suggest that a part of the cloud lifecycle; transition from the non-drizzle to drizzle stage can be well expressed by the CFODD of individual clouds. While, the cloud lifecycle on the RE-COT pattern was obscure. This advantage of CFODD over the RE-COT pattern arises because the CFODD uses vertical information of the inner cloud, whereas the effective radius of the RE-COT diagram presents property near the cloud top. Our results emphasize that future satellite observations should retrieve vertical information such as the effective radius at each height with high frequency to capture the lifecycle of individual clouds. This paper presents useful suggestion that will be useful to the satellite user community for retrieving the shallow-cloud lifecycle.

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In July and August (JA) 2018, the monsoon trough in the western North Pacific (WNP) was unusually strong, the anticyclonic ridge was anomalously northward-shifted, and enhanced and northward-shifted tropical cyclone activity was observed. Studies have examined the effects of sea surface temperature (SST) anomalies on the North Atlantic (NA), the Indian Ocean (IO), and the tropical North Pacific. However, a synthetic view of SST forcings has yet to be identified. Based on a series of numerical experiments, this study demonstrated that the SST anomaly in the tropical WNP was the key forcing that formed the structure of the observed anomalous phenomena in the monsoon trough. Moreover, the combined effect of the SST anomaly in both the tropical and extratropical WNP resulted in enhanced circulation anomalies in the WNP. The NA SST anomaly also enhanced the monsoon trough in the presence of WNP SST anomaly. By contrast, the individual SST anomaly in the NA, IO, the extratropical WNP, and the subtropical eastern North Pacific could not force the enhanced monsoon trough. We proposed that the local effect of both the tropical and extratropical WNP SST anomaly as the major driver and the remote effect of NA SST anomaly as a minor contributor jointly induced the anomalous circulation and climate extremes in the WNP during JA 2018.

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2007年4月から12月にかけて，温排水流入河川に生息するティラピア（ナイルティラピア Oreochromis niloticus とジルティラピア Tilapia zillii）の野生個体の成長を標識再捕法によって調べた。全長および体重は水温の上昇に伴い増加したが，低下すると大型個体（体重⟩400 g）の体重は減少したが，小型個体（体重⟨400 g）では変化しないかわずかに上昇した。大型個体の全長・体重間の関係式に季節変化が確認された。11月上旬の一時的な工場の操業停止で温排水の流入が停止した際は，ティラピアの個体群にへい死などの悪影響がもたらされたが，生存個体の成長に目立った影響はなかった。本研究からティラピアの成長は魚体サイズと季節（水温）に支配されることが示された。また，全長・体重の関係式は大まかなティラピアの季節変化を知る上で有用であることが示唆された。

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To investigate factors affecting the evolution of nitrogen system in rocks during progressive metamorphism, unmetamorphosed to greenschist-facies pelitic samples were collected from both pelitic and (pelitic members of) psammitic rock sequences along two transects of the Taiwan mountain belt. Among all samples, greenschist-facies metapelites from the Tananao metamorphic basement of this mountain belt exhibit the most variable and depleted nitrogen content and δ¹⁵N values. The observations are difficult to interpret and can only be accounted for by complicated tectonic/metamorphic history of the basement complex. On the other hand, irrespective of the different metamorphic grades, samples from the metamorphosed cover strata, which have been subjected to only one stage of metamorphism, show comparable nitrogen and N-isotope composition. The only exception is that greenschist-facies metapelites from the pelitic members of psammitic rock sequence (i.e., the G(Ps) group samples) of the cover strata are enriched in the ¹⁵N isotope by at least 1‰. Taking Al content as a normalizing factor, averaged N/Al and LOI/Al show systematic decrease through progressive metamorphism. Given the non-homogeneous nature of the sedimentary protoliths, the comparable N-isotope composition among the unmetamorphosed to zeolite-facies (i.e., S-Z) group, prehnite-pumpellyite-facies (i.e., PP) group and greenschist-facies (i.e., G) group samples from pelitic rock sequences can be explained by rock devolatilization with limited nitrogen depletion (<10%). High δ¹⁵N composition of the G(Ps) group samples might be mainly due to more extensive nitrogen depletion (∼25%). It is suggested that during metamorphism, the pelitic rock sequence may approximate a closed system, while thick psammitic rock sequence may behave more like an open system, facilitating nitrogen depletion and N-isotope fractionation even for thin pelitic members within a thick psammitic sequence. Lithology, in addition to other factors, therefore plays a role in controlling the evolution of the nitrogen system during low-grade metamorphism. The present study implies that element transport by dehydration fluid in subduction zones may largely take place along fluid channel ways.

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While most studies have argued a slower increase of 1-3% K⁻¹ of precipitation globally, others note that this is not necessarily the case from a regional perspective. In this study, we examine the convective structure

over the equatorial Pacific with highly increased precipitation under global warming using simulations from the High Resolution Atmospheric Model (HiRAM). The moisture budget analysis shows that the precipitation increases must result from a significant enhancement of convection, with a minor modulation from the thermodynamic effect. Two different types of enhanced convection are identified. Over the mean ascending region, precipitation increases are associated with an enhancement of deep convection; while over the mean descending region, the precipitation increases are a result of enhanced shallow convection.

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Over the tropics, two types of precipitation systems (PSs), super clusters (SCs) and Madden Julian Oscillation (MJO), are frequently observed, having similar meridionally symmetric structures about the equator but different eastward-propagating (EP) speeds. To investigate the reasons why these PSs exist, the dependence of the longitudinal variations of surface sea temperature (SST) is examined using a NICAM on an aqua-planet. In a longitudinally uniform-SST case, only SC-like fast-EP PSs appear. When the longitudinal variation of the SST increases, meanwhile, a stationary Walker circulation (WC) emerges and MJO-like slowly EP PSs occur on the western part of a high-SST area. It is expected in the real atmosphere that two different types of EP PSs can exist in parallel due to complex surface conditions: 1) SCs as free PSs and 2) MJOs as forced PSs. Here, free (forced) PSs mean convection, which is uncontrolled (controlled) by the longitudinal variation of the SST. It is also obtained that an asymmetric WC is produced, even though the SST variation symmetric about 180° longitude is forced. Owing to the WC, combined with the Hadley circulation, the MJO is generated and decayed locally, and westward-propagating PSs are dominantly observed in the subsidence areas of the WC.

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Using the Non-hydrostatic ICosahedral Atmospheric Model (NICAM) on an aqua-planet with a uniform longitudinal sea surface temperature, precipitation systems (PSs) with coarse horizontal resolutions are studied. An eastward-propagating (EP) property of the PSs is seen even though the horizontal resolution becomes coarser to 112 km, as long as the vertical stratification is kept conditionally unstable. The appearance or disappearance of the EP property is explained in comparison with mesoscale (100 km) and large-scale (1,000 km) PSs, a non-precipitation system (NPS), and a system simulated by a dry model with positive-only wave CISK heating (DP). By assuming that the height and the updraft intensity of convection are common in these systems, the turnover times of representative convections are estimated. Compared with the time scale of the equatorial beta (T_β), where its effect essentially works and the distinct EP property appears, the turnover times of the large-scale PS and DP are longer than T_β, producing the EP property, whereas those of the NPS and mesoscale PSs are shorter, inducing no EP property. These results are consistent with observations and model outputs (Nakazawa 1988; Nasuno et al. 2007, 2008).

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　駿河湾奥の富士川河口右岸に位置する蒲原海岸を対象として，1952年以降2010年までに撮影された空中写真，深浅測量データ，および2008年11月と2010年1月に実施したNMB（Narrow multibeam）測量データなどを基に地形変化の実態を明らかにした．当海岸では沖合に海底谷が発達しているため海底勾配が急であり，このため消波施設として有脚式離岸堤が設置されている．このような特徴を有する海岸での地形変化実態を現地実測により明らかにした．

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Using a simple semi-synthetic competence and sporulation medium (CSM), we found evidence that Bacillus subtilis cells transformed in the competence phase can sporulate, indicating that genetic information acquired during the competence phase is inherited by the next generation after germination of the transformed spores. Moreover, the results from mixed cell culture experiments suggest that spontaneous genetic transformation can occur between competent cells and DNA released from lysed cells in the natural environment. We also found evidence that the spontaneous transformation system can be used for genetic mapping in B. subtilis.

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A radiologic study was made on 184 male asbestos workers in order to determine the effects of smoking on asbestos-related pulmonary and pleural . The effects of smoking on the prevalence of pleural could not be demonstrated, but the prevalence of pulmonary significantly increased with length of smoking history (p<0.01). It was found that smoking elevated the prevalence of asbestos-related pulmonary . These findings are of great importance in the health management of asbestos workers.

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