Nitrate Loss for Denitrification during High Frequency Research in Floodplain Groundwater of the Tama River

This study aims to identify the possible roles of a floodplain inbiogeochemical nitrogen cycles, based on analysis of groundwaterdynamics of inorganic nitrogen species. Groundwater samples collected from boreholes made of poly vinyl chloride located onthe floodplain in the middle reach of the Tama River, Nagata district were analyzed for dissolved organic carbon, dissolved oxygen, inorganic nitrogen compounds, major anions and the stableisotope ratio of nitrate-nitrogen.Dissolved oxygen in groundwater samples collected from marked borehole (G-5) was low (50 ± 16 μM) and nitrate decreasedfrom 63 μM to < 10 μM during our research period. Concentrations of nitrate, nitrite and nitrous oxide decreased one after the other. These decreases in concentration, combinedwith ¹⁵N-enrichment of groundwater nitrate suggest denitrification as a significant nitrate sink, yielding an isotopic fractionation of nitrate-nitrogen with an enrichment factor (ε= –17.9‰) that is comparable tothose in various soil and groundwater systems. This study provesthat floodplains can perform as nitrogen sinks for groundwaterin river catchments.     

Zacatecas (Mexico) Companies Extract Hg from Surface Soil Contaminated by Ancient Mining Industries

In Zacatecas, Mexico, four plants are operating to extract Ag, Au, and Hg using CaS₂O₃ solution from surface soil containing tailings from the amalgamation method used during 1550–1900. The metal ions extracted are cemented by scrap Cu wires. Hg is separated by evaporation from the cemented amalgam and Ag and Au are obtained from the residue. A part of the soil to be leached was separated and leached as in the industrial process. Only 121 ppm of Hg was freed from 168 ppm of extractable Hg. About a half of the remaining Hg in the soil evaporated during 18 months. This confirms that the Hg in the soil is metallic. Pb and As are also freed in the same process. It is estimated that 13 000–34 000 t of Hg had been discarded in the extraction of Ag.     

Emergy assessment of a coffee farm in Brazilian Cerrado considering in a broad form the environmental services, negative externalities and fair price

A new way of thinking about conservation is represented by the preservation of native areas and the payment for their environmental services. In the present study emergy synthesis was applied to assess the environmental performance of a coffee farm located in Coromandel, Minas Gerais, in the Brazilian Cerrado. The farm produces green coffee for exportation, and holds an area with native vegetation of 80 ha, larger than that required by Brazilian legislation. The assessment of the native area within the farm was carried out in order to determine its environmental sustainability. The emergy ternary diagram was employed to interpret the results, which show that a farm with 54 ha of productive area must be matched with 200 ha of native vegetation for medium term sustainability. The Cerrado’s farm production is primarily for export, and an evaluation of the environment and economic changes with respect to importing countries was performed. Emergy synthesis is proposed to calculate the price of environmental services balancing trades in the international market. A discussion of the problem of assigning payments for environmental services is presented.     

Inhibition strength of short peptides derived from an ACE inhibitory peptide

A series of peptides, derived from an ACE inhibitory peptide (VTVNPYKWLP) found in our previous work, were synthesized. Their half maximal inhibition concentrations (IC(50)) for ACE inhibition have been determined. The effect of amino acid sequence on ACE inhibition was discussed on the basis of IC(50) of the synthetic peptides, and the following characteristics of the ACE inhibitory peptide have been clarified. First, the active portion of this peptide for ACE inhibition is KW. Second, the amino acid sequences near this dipeptide (KW) have a strong effect on the inhibitory activity. Especially, the proline residue in the C-terminal end strongly enhanced ACE inhibition. It should be noted that the IC(50) value of KWLP (5.5 μM) is the same as the ACE inhibitory peptide (VTVNPYKWLP) and that the IC(50) value of KW is 7.8 μM. The stability and absorption efficiency in vivo would be significantly improved by shortening the peptide length from 10 amino acids to four amino acids or two amino acids.     

Birth of normal mice following round spermatid injection without artificial oocyte activation

For fertilization using round spermatid injection (ROSI) in mice, oocytes need to be artificially preactivated because of the lack of oocyte-activating capacity in round spermatids of this species. However, when round spermatids were frozen-thawed before microinjection, 11-71% of injected oocytes developed into 2-cell embryos without any artificial activation. After being transferred into recipient females, 5-27% of these embryos reached term. At least some of the injected oocytes showed intracellular Ca(2+) oscillations, which normally occur after fertilization by mature spermatozoa. Thus, these round spermatids could transmit a sperm-borne oocyte-activating factor, which might have been released from spermatozoa and elongated spermatids in the same suspension by freezing and thawing. This possibility was further supported by activation of intact oocytes following transplantation of the pronuclei from ROSI-generated embryos. Thus, one-step ROSI can be achieved in mice simply by injecting frozen-thawed round spermatids into intact oocytes. Clearly, there is a need for careful interpretation of microinjection experiments when assessing the oocyte-activating capacity of spermatogenic cells, especially when they are derived from frozen-thawed stocks.     

The Arterial Supply of the Female Reproductive System in the Hamster

The arterial supply to the pelvis and female reproductive system was studied in 54 hamsters of the CBN, APG and ACN strains, 3 rats of the Wistar strain and 3 mice of the ICR strain. All animals were prepared by intravascular injection of a mixture of barium and red latex for gross dissection and radiographic examination. The vascular patterns of the three strains of hamsters were compared with each other and with those of rats and mice. The possible reasons for variations within and between species are discussed.     

Cesium-137 discharge into the freshwater fishery ground of grazing fish, ayu Plecoglossus altivelis after the March 2011 Fukushima nuclear accident

The Fukushima nuclear accident led to deposition of radionuclides into the freshwater fishery ground of ayu Plecoglossus altivelis. For the purpose of more comprehensive understanding of the radioactive contamination, cesium-137 (¹³⁷Cs) was analyzed in running water, muddy sediment, attached algae, and ayu using samples from three river systems with different levels of contamination within Fukushima Prefecture in summer and autumn 2011. The amount of ¹³⁷Cs contained in water as well as in sediment declined over an interval of two months, although the concentration in sediment samples was up to 10,000-fold higher than that in water samples. The changes in ¹³⁷Cs concentration of algae showed different courses among the three river systems, the concentration being greater in autumn in the river systems with high and moderate radioactive contamination. ¹³⁷Cs detected within a single stock of ayu appeared to be excreted rather rapidly with a calculated half-life of approximately 39 days, while the concentration ratio ranged from 10³ to 10⁴ l/kg, attaining higher levels than previously reported. These findings indicate that the most important pathway of ¹³⁷Cs into ayu is via intake of algae as food but that the retention time of ¹³⁷Cs inside ayu is relatively short.     

华北潮土区不同肥力水平土壤基础地力研究

农田基础地力提升对于减施肥料和作物稳产高产有着重大现实意义。为了研究华北潮土区土壤基础地力情况,在河南省典型潮土区原阳县、周口市、夏邑县等不同肥力水平的土壤上,通过2年大田试验及统计分析方法,观测和分析小麦-玉米轮作体系下土壤基础地力变化。结果表明:2012年和2013年小麦季的基础地力贡献率分别为78.1%和76.7%,略高于玉米季的71.9%和74.4%;2012年和2013年两季作物的平均基础地力贡献率分别为74.5%和75.1%,低肥力和高肥力水平土壤的地力贡献率没有显著差异。因此,华北潮土区小麦玉米轮作下土壤基础地力贡献率在75%左右。     

Distribution and migration of radiocesium in sloping landscapes three years after the Fukushima-1 nuclear accident

The results of the study are presented on the distribution and migration of radiocesium in mountainous (580–620 m a.s.l.) landscapes in the northeast of Honshu Island (Tohoku Region, Miyagi Prefecture) subjected to radioactive contamination after the nuclear accident at Fukushima-1 NPP. In July 2014, the average contamination density with radiocesium (¹³⁴Сs and ¹³⁷Сs) over the territory (150 km to the northwest from NPP) was equal to 16 kBq/m². This contamination is estimated at the acceptable level according to both Japanese and Russian standards and legislation. Three years after the accident, radiocesium is found to be unevenly distributed by the biogeocenosis components, i.e. 45% in litter, 40% in plants, 10% in soil, and 5% in roots. As for the distribution of total radiocesium (Cs tot = ¹³⁴Сs + ¹³⁷Сs) by the profile of volcanic podzolic-ocherous soil (Dystric Aluandic Andosols), its maximal content (about 80%) was found in the surface layer (0–2.5 cm), with the specific activity ranging from 250 to 10070 Bq/kg and sharply decreasing with the depth. Radiocesium amount in the soils of forest ecosystems was on average by 20% higher than in meadow ecosystems. Accumulation of radionuclides in soils of lower and middle parts of a slope with an insignificant vertical migration was found to be the most general regularity. The air dose rate did not exceed the maximal permissible level, and the snow cover acted as an absorbing and scattering screen.     

Effect of fish in rice-fish culture on the rice yield

Rice-fish culture, which means the simultaneous culture of rice and fish, is one of the best options to increase food production from limited land and is practiced in many countries in the world. Although many researchers and farmers believe that the rice yield is increased by fish farming in paddy fields, this hypothesis has never been fully tested. Here, we report ecological processes leading to higher rice yields in the rice-fish culture using crucian carp (Carassius complex), which have adapted to the paddy field ecosystem in Japan. We compare the rice-fish and rice-only plots in the experimental paddy field for biota, water quality, and rice yield. Coverage of duckweed and densities of zooplankton and benthic invertebrates in the rice-fish plots were lower than those in the rice-only plots, indicating that fish utilized them as food. NO₃–N concentration in the rice-fish plots was higher than that in the rice-only plots, indicating that the increase in NO₃–N concentration results from excretion of unutilized food nutrients by the fish. Consequently, rice yield in the rice-fish plots was 20% higher than that in the rice-only plots. The fertilizing effect of the fish excrement probably increased rice yield.