Reservoir sediments – a witness of mining and industrial development (Malter Reservoir, eastern Erzgebirge, Germany)

The Malter Reservoir is situated about 30 km south of Dresden (eastern Germany) in a historical mining area of the eastern Erzgebirge. It was built in 1913 for the protection from floodwaters, droughts and for generating electricity. The river Rote Wei?eritz is the main source of clastic input into the lake. Geochemical and sedimentological data of gravity-and piston-cores, recovered from the deepest point of the lake, document the environmental history of the drainage area since 1963. ¹³⁷Cs dating gives an average sedimentation rate of ∼2.9 cm/year. Within the whole core, heavy metals are strongly enriched (parentheses refer to enrichment factors as compared with average shale): cadmium (290), silver (140), bismuth (90), antimony (25), lead (21), zinc (14), tin (13), uranium (9), tungsten (9), molybdenum (5), copper (4), thallium (3) and chromium (2). Enrichments are detectable for the whole registered time-period of 81 years. Peaks of up to 27 mg/kg silver, 37 mg/kg bismuth, 91 mg/kg cadmium, 410 mg/kg chromium, 240 mg/kg copper, 20 mg/kg molybdenum, 14000 mg/kg phosphorus, 740 mg/kg lead, 6,5 mg/kg antimony, 74 mg/kg tin, 52 mg/kg tungsten and 1900 mg/kg zinc reflect local events caused by human impact. Inputs from different pollution sources at different times are represented by highly variable elemental concentrations and ratios within the core. High pH values within the water and the sediment column, the large adsorption capacity of the fine-grained C_org.-rich sediment, and the presence of low Eh-values and sulphide ions in the sediment prevent the remobilisation of the toxic elements. Erosion of these contaminated sediments during floods, channel flows or resuspension during removal of the sediments may lead to a downstream transfer of pollutants. Contents of P and C_org., as well as diatom abundance, indicate a change from oligotrophic to eutrophic conditions in the lake during ∼1940–1950. This was mainly caused by high agricultural activity in the drainage area. Reduced contents of Cu, Zn, Cd and Cr since the reunification of East and West Germany are obviously caused by increasing environmental protection measures, such as wastewater purification and especially the closing of contaminating industries. Revision received: 23 September 1999 · Accepted: 17 December 1999     

Effects of mass source/sink at the western boundary on the wind-driven gyres: Implications for the ventilation of the north pacific intermediate layer through convection in the Okhotsk Sea and tidal mixing at the Kuril Straits

A steady quasi-geostrophic 2.5-layer model, forced by both Ekman pumping and a mass source/sink situated at the western boundary has been constructed to investigate the effect of diapycnal transport due to convection in the Okhotsk Sea and tidal mixing at the Kuril Straits on the intermediate layer in the North Pacific. The model illustrates a combined effect of the wind-driven and mass-driven circulations. First, net mass input induces a “barotropic” mode inter-gyre flow along the western boundary through the dynamical influence of Kelvin waves. This flow creates characteristic curves (geostrophic contours) that facilitate inter-gyre communication through the western boundary layer from the location of the mass source to the subtropical gyre. Due to the effect of wind-driven circulation, the offshore part turns eastward into the interior, encircles the outer rim of the region (which would otherwise be the pool region in the absence of mass input), and then encounters the western boundary. Eventually, the water fed into the lower layer flows mostly along this path and later flows away to the equatorial region. Conversely, in the upper layer, water is fed from the equator to the subtropics, and to the subpolar interior region through the western boundary current. The water then circulates along the outer rim and is absorbed into the mass sink. The model is controlled mainly by three nondimensional parameters: (1) the ratio of net mass input rate to the maximum Sverdrup transport (Q/T _Sv ^max ), which affects the inter-gyre communication by altering the paths of geostrophic contours, (2) the ratio of a mass input rate into the lower layer to that in total (Q ₂/Q), which controls the vertical structure of the inter-gyre flow, and (3) the measure of the wind forcing effect relative to the β effect, which determines the horizontal extent of the area influenced by the mass input. The other parameter regimes with respect to Q/T _Sv ^max and Q ₂/Q are also presented.     

不饱和古罗糖醛酸三糖和甘露糖醛酸三糖的结构表征

以双功能褐藻胶裂解酶 (Pseudoalteromonas sp.strain No. 2 72 )分别降解均聚古罗糖醛酸(PG)和均聚甘露糖醛酸 (PM) ,经 Bio- Gel- P6和 POROS- HQ2 0分离得到 2种三糖纯品 ,经 ESI- MS,1 H- NMR,1 3 C- NMR,1 H- 1 H COSY,1 H- 1 3 C HMQC确定其结构为 Δ4,5-古罗糖醛酸 - α(1→ 4 ) - L-古罗糖醛酸 -α(1→ 4 ) - L -古罗糖醛酸 (简写为Δ GG)和Δ4,5-甘露糖醛酸 -β (1→ 4 ) - D-甘露糖醛酸 -β (1→ 4 ) - D-甘露糖醛酸 (ΔMM) ,为进一步从事构效关系研究提供结构信息。     

Verification of net primary production estimation method in the Mongolian Plateau using landsat ETM+data

We plan to estimate global net primary production (NPP) of vegetation using the Advanced Earth Observing Satellite-II (ADEOS-II) Global Imager (GLI) multi-spectral data. We derive an NPP estimation algorithm from ground measurement data on temperate plants in Japan. By the algorithm, we estimate NPP using a vegetation index based on pattern decomposition (VIPD) for the Mongolian Plateau. The VIPD is derived from Landsat ETM+multi-spectral data, and the resulting NPP estimation is compared with ground data measured in a semi-arid area of Mongolia. The NPP estimation derived from satellite remote sensing data agrees with the ground measurement data within the error range of 15% when all above-ground vegetation NPP is calculated for different vegetation classifications.     

Biogenic Silica Record in Lake Biwa of Central Japan over the Past 145,000 Years

The record of the biogenic silica flux (BSF, g cm⁻²(10³yr)⁻¹) in Lake Biwa reflects changes in diatom productivity in the lake and provides information regarding changes in paleoclimatic conditions. The BSF record of Lake Biwa demonstrates five periods over the past ca. 145,000 yr when the BSF values were significantly greater than 7.5 g cm⁻²(10³yr)⁻¹, and five intervals when they were lower. The data imply that paleoclimatic conditions were warmer and wetter from ca. 123,000 to 115,000, 103,000 to 95,000, 88,000 to 72,000, 57,000 to 32,000 yr B.P., and around ca. 6000 yr B.P. when the BSF values were greater, and relatively dry and cold from ca. 141,000 to 123,000 yr B.P. and during intervals between two of the five warm and wet episodes when the BSF values were lower. Time series of the BSF record can be correlated with the record of biogenic silica content in Lake Baikal and the marine oxygen isotope stages 1 through 6. Furthermore, the BSF values varied with much higher amplitude during the last interglaciation than during the last glaciation, probably implying that the diatom productivity in Lake Biwa was likewise more variable and had a larger range under interglacial conditions than under glacial conditions.     

Impact of flood events on macrobenthic community structure on an intertidal flat developing in the Ohta River Estuary

We investigated the effects of river floods on the macrobenthic community of the intertidal flat in the Ohta River Estuary, Japan, from 2005 to 2010. Sediment erosion by flood events ranged from about 2–3 cm to 12 cm, and the salinity dropped to 0‰ even during low-intensity flood events. Cluster analysis of the macrobenthic population showed that the community structure was controlled by the physical disturbance, decreased salinity, or both. The opportunistic polychaete Capitella sp. was the most dominant species in all clusters, and populations of the long-lived polychaete Ceratonereis erythraeensis increased in years with stable flow and almost disappeared in years with intense flooding. The bivalve Musculista senhousia was also an important opportunistic species that formed mats in summer of the stable years and influenced the structure of the macrobenthic community. Our results demonstrate the substantial effects of flood events on the macrobenthic community structure.     

Multiple Parameter Regularization: Numerical Solutions and Applications to the Determination of Geopotential from Precise Satellite Orbits

Kaula’s rule of thumb has been used in producing geopotential models from space geodetic measurements, including the most recent models from satellite gravity missions CHAMP. Although Xu and Rummel (Manuscr Geod 20 8–20, 1994b) suggested an alternative regularization method by introducing a number of regularization parameters, no numerical tests have ever been conducted. We have compared four methods of regularization for the determination of geopotential from precise orbits of COSMIC satellites through simulations, which include Kaula’s rule of thumb, one parameter regularization and its iterative version, and multiple parameter regularization. The simulation results show that the four methods can indeed produce good gravitational models from the precise orbits of centimetre level. The three regularization methods perform much better than Kaula’s rule of thumb by a factor of 6.4 on average beyond spherical harmonic degree 5 and by a factor of 10.2 for the spherical harmonic degrees from 8 to 14 in terms of degree variations of root mean squared errors. The maximum componentwise improvement in the root mean squared error can be up to a factor of 60. The simplest version of regularization by multiplying a positive scalar with a unit matrix is sufficient to better determine the geopotential model. Although multiple parameter regularization is theoretically attractive and can indeed eliminate unnecessary regularization for some of the harmonic coefficients, we found that it only improved its one parameter version marginally in this COSMIC example in terms of the mean squared error.     

Fukuititan nipponensis, A New Titanosauriform Sauropod from the Early Cretaceous Tetori Group of Fukui Prefecture,Japan

<正>A titanosauriform dinosaur:Fukuititan nipponensis gen.et sp.nov.is erected based on the incomplete skeleton.It is characterized by elongated asymmetric tooth crown with a weak or absent labial groove and without lingual concavity;stalk-like epipophysis of cervical vertebra;the transverse width of the proximal end of the humerus approximately 32%of the humerus length;metacarpal longer,approximately 48%of the radius and the distal end of the ischia slightly expanded.It represents the first relatively complete titanosauriform skeleton found from Japan.The discovery of Fukuititan indicates that the diversity and geographical distribution of Titanosauriformes are much higher than the previous thought.     

Current-to-Current Converter for Scientific Underwater Cable Networks

A new current-to-current converter, which is a key device to branch a constant direct current (DC) into two constant DCs, was proposed [K. Asakawa , Proc. OCEANS, pp. 1868-1873, 2003]. It has been verified, through computer simulations and experiments using prototypes, to have good conversion efficiency and stable operation. Because the basic circuit is simple, high reliability is expected. The current-to-current converter is a key device to realize a constant current (CC) power-feeding system for scientific underwater cable networks having mesh topology, which is necessary to enhance robustness against cable breakdowns and to deploy sensors in 2-D and efficiently over a vast research area.     

New approaches for archaeal genome-guided cultivation

Archaea, one of the three domains of life along with Bacteria and Eukarya, contains ancient life forms such as methanogen that are observed today on Earth, and one lineage Asgard archaea is also considered the closest ancestor of Eukarya.Recently, with the development of interdisciplinary studies from Earth and Life sciences, archaeal organisms are considered to play pivotal roles in geochemical cycling in nature. However, our understanding of the attributes, origin and evolution, geochemical and ecological functions of Archaea is hampered by the scarcity of archaeal isolates, which has represented a challenge to researchers for the last 40 years. Cultivation-independent sequencing and phylogenomic analyses have demonstrated a considerable diversity of Archaea with more than 20 novel phyla. However, only four archaeal phyla have cultured representatives, leaving large gaps in our knowledge of the metabolic capabilities and ecological functions of the majority of archaeal strains identified exclusively by DNA sequencing. In this review, we summarize the discovery and development of archaeal research, highlight the knowledge gap between uncultured and cultured archaeal microbes, and call on the importance of devoting greater research efforts to archaeal cultivation. Finally, we outlined new ideas and strategic approaches, namely,(1)genome-based methods,(2) microbial network information-based methods,(3) genome-scale model-guided methods, and(4)machine learning methods, to enable the cultivation of uncultivated archaeal microbes using accumulated high-throughput sequencing data.