Methane emissions from different vegetation zones in a Qinghai-Tibetan Plateau wetland

We measured methane (CH₄) emissions in the Luanhaizi wetland, a typical alpine wetland on the Qinghai-Tibetan Plateau, China, during the plant growth season (early July to mid-September) in 2002. Our aim was to quantify the spatial and temporal variation of CH₄ flux and to elucidate key factors in this variation. Static chamber measurements of CH₄ flux were made in four vegetation zones along a gradient of water depth. There were three emergent-plant zones (Hippuris-dominated; Scirpus-dominated; and Carex-dominated) and one submerged-plant zone (Potamogeton-dominated). The smallest CH₄ flux (seasonal mean=33.1 mg CH₄ m⁻² d⁻¹) was observed in the Potamogeton-dominated zone, which occupied about 74% of the total area of the wetland. The greatest CH₄ flux (seasonal mean=214 mg CH₄ m⁻² d⁻¹) was observed in the Hippuris-dominated zone, in the second-deepest water area. CH₄ flux from three zones (excluding the Carex-dominated zone) showed a marked diurnal change and decreased dramatically under dark conditions. Light intensity had a major influence on the temporal variation in CH₄ flux, at least in three of the zones. Methane fluxes from all zones increased during the growing season with increasing aboveground biomass. CH₄ flux from the Scirpus-dominated zone was significantly lower than in the other emergent-plant zones despite the large biomass, because the root and rhizome intake ports for CH₄ transport in the dominant species were distributed in shallower and more oxidative soil than occupied in the other zones. Spatial and temporal variation in CH₄ flux from the alpine wetland was determined by the vegetation zone. Among the dominant species in each zone, there were variations in the density and biomass of shoots, gas-transport system, and root-rhizome architecture. The CH₄ flux from a typical alpine wetland on the Qinghai-Tibetan Plateau was as high as those of other boreal and alpine wetlands.     

Ion Transport Dynamics in Acid Variable Charge Subsoils

This is a mini-review of the research work conducted by the authors with the objective of studying ion transport in variable charge subsoils collected from different areas around the world. An attempt is made in these studies to relate the unique behavior manifested during ionic transport in these subsoils with their mineralogical, physical and chemical properties, which are markedly different from those in soils from temperate regions. The variable charge subsoils have a relatively high salt sorption capacity and anion exchange capacity (AEC) that retards anions downward movement. The AEC correlates closely with the anion retardation coefficients. Ca²⁺ applied with gypsum in topsoil may be transported to the subsoil and may improve the subsoil chemical properties. These results may help in developing appropriate management strategies under a range of mineralogical, physical, and chemical conditions.     

Fog and Precipitation Chemistry at Mt. Rokko in Kobe, April 1997-March 1998

Fog water and precipitation were collected and analyzed to study fog and precipitation chemistry. The research was carried out through one year from April 1997 to March 1998 at Mt. Rokko in Kobe. Higher fog occurrence and larger volume of fog water were observed in summer, corresponding to the trend of seasonal variation in precipitation amount. The annual mean pH value of fog water (3.80) was lower by ca. one pH unit than that of precipitation (4.74). The concentration of chemical species in fog water was ca. 7 times that in precipitation. The highest anion and cation concentrations were SO₄ ^2? and NH₄ ⁺ in fog water and Cl^? and Na⁺ in precipitation, although the Cl^?/Na⁺ equivalent ratio in both fog water and precipitation was almost the same value as that in sea water. It is considered that in the longest fog event, NH₄ ⁺ and nss-SO₄ ^2? in fog water mainly scavenged as (NH₄)₂SO₄, mainly derived from (NH₄)₂SO₄ (aerosol) in the atmosphere, NH₃ was scavenged at the growing stage, and SO₂ was also scavenged after the mature stage. NO₃ ^? in this fog event was mainly absorbed as HNO₃.     

Oxygen isotopic compositions of asteroidal materials returned from Itokawa by the Hayabusa mission

Meteorite studies suggest that each solar system object has a unique oxygen isotopic composition. Chondrites, the most primitive of meteorites, have been believed to be derived from asteroids, but oxygen isotopic compositions of asteroids themselves have not been established. We measured, using secondary ion mass spectrometry, oxygen isotopic compositions of rock particles from asteroid 25143 Itokawa returned by the Hayabusa spacecraft. Compositions of the particles are depleted in (16)O relative to terrestrial materials and indicate that Itokawa, an S-type asteroid, is one of the sources of the LL or L group of equilibrated ordinary chondrites. This is a direct oxygen-isotope link between chondrites and their parent asteroid.     

Molecular and biological characterization of <Emphasis Type="Italic">Chrysanthemum stem necrosis virus</Emphasis> isolates from distinct regions in Japan

Three isolates of Chrysanthemum stem necrosis virus (CSNV) were obtained from chrysanthemum plants in distinct regions of Japan in 2006 and 2007. All the original host plants showed severe necrotic symptoms on the leaves and stems. Amino acid sequence data of the nucleocapsid protein genes of the three isolates (CbCh07A, TcCh07A, and GnCh07S) showed high identities with those of two other CSNV isolates, HiCh06A L1 from Japan and Chry1 from Brazil. Furthermore, for the first time the complete nucleotide sequence of the S RNA was determined for CSNV (isolate HiCh06A). In phylogenetic analysis based on the non-structural protein genes from the genus Tospovirus, HiCh06A L1 was placed in the same genetic group as Tomato spotted wilt virus (TSWV) and Impatiens necrotic spot virus. Host range examination for isolates HiCh06A L1 and CbCh07A showed that green pepper (cv. ‘Kyoyutaka’, ‘Saitamawase’, ‘Tosakatsura’, ‘L3 sarara’ and ‘L3 miogi’) and tomato (cv. ‘Sekaiichitomato’) were systemically susceptible hosts, whereas TSWV-resistant Solanaceae species, Capsicum chinense, Lycopersicon peruvianum and a TSWV-resistant cultivar of green pepper (cv. TSR miogi), were resistant.     

Resveratrol in raw and baked blueberries and bilberries

Resveratrol in the fruits of bilberry (Vaccinium myrtillus L.), the lowbush "wild" blueberry (Vaccinium angustifolium Aiton), the rabbiteye blueberry (Vaccinium ashei Reade), and the highbush blueberry (Vaccinium corymbosum L.) were measured using a new assay based on high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS). The LC-MS/MS assay provided lower limits of detection than previous methods for resveratrol measurement, 90 fmol of trans-resveratrol injected on-column, and a linear standard curve spanning >3 orders of magnitude. The recoveries of resveratrol from blueberries spiked with 1.8, 3.6, or 36 ng/g were 91.5 +/- 4.5, 95.6 +/- 6.5, and 88.0 +/- 3.6%, respectively. trans-Resveratrol but not cis-resveratrol was detected in both blueberry and bilberry samples. The highest levels of trans-resvertatrol in these specimens were 140.0 +/- 29.9 pmol/g in highbush blueberries from Michigan and 71.0 +/- 15.0 pmol/g in bilberries from Poland. However, considerable regional variation was observed; highbush blueberries from British Columbia contained no detectable resveratrol. Because blueberries and bilberries are often consumed after cooking, the effect of baking on resveratrol content was investigated. After 18 min of heating at 190 degrees C, between 17 and 46% of the resveratrol had degraded in the various Vaccinium species. Therefore, the resveratrol content of baked or heat-processed blueberries or bilberries should be expected to be lower than in the raw fruit. Although blueberries and bilberries were found to contain resveratrol, the level of this chemoprotective compound in these fruits was <10% that reported for grapes. Furthermore, cooking or heat processing of these berries will contribute to the degradation of resveratrol.     

Acylated and non-acylated flavonol monoglycosides from the Indian minor spice Nagkesar (Mammea longifolia)

A methanol extract of nagkesar (buds of Mammea longifolia), which showed strong radical scavenging activity, yielded 13 compounds by separations using column chromatography and HPLC. Structure elucidation of these compounds was achieved by (1)H and (13)C NMR, including DQF-COSY, TOCSY, DEPT, HMQC, HSQC, and HMBC. They include two new compounds, quercetin 3-O-(2' ',4' 'di-E-p-coumaroyl)-alpha-L-rhamno-pyranoside and quercetin 3-O-(3' ',4' '-di-E-p-coumaroyl)-alpha-L-rhamnopyranoside, along with known compounds kaempferol, quercetin, the isopropylidenedioxy derivative of shikimic acid, kaempferol 3-O-(2' ',4' '-di-E-p-coumaroyl)-alpha-L-rhamnopyranoside, kaempferol 3-O-(3' ',4' '-di-E-p-coumaroyl)-alpha-L-rhamnopyranoside, kaempferol 3-O-alpha-L-rhamnopyranoside, quercetin 3-O-alpha-L-rhamnopyranoside, shikimic acid, kaempferol 3-O-beta-D-glucopyranoside, quercetin 3-O-beta-D-glucopyranoside, and beta-sitosterol 3-O-beta-D-glucopyranoside.     

Effect of the strain combination of the donor and recipient on the production efficiency of W‐bearing sperm in mixed‐sex germline chimeric chickens

Effect of the strain combination of the donor and recipient on production efficiency of W‐bearing sperm in mixed‐sex chimeric testes was analyzed. The combinations of the donors and recipients were White Leghorn (WL) and Rhode Island Red (RIR), and vice versa. Generated mixed‐sex chimeras that had the male phenotype at sexual maturity were classified into four groups: (1) a female WL donor and a male RIR recipient; (2) a male WL donor and a female RIR recipient; (3) a female RIR donor and a male WL recipient; (4) a male RIR donor and a female WL recipient. The mean number of W‐bearing sperm detected by in situ hybridization among 10 000 sperm observed were 147, 165, 30 and 45 in groups 1, 2, 3 and 4, respectively. The numbers in groups 1 and 2 were both significantly higher than those of groups 3 and 4 (P < 0.05). The combination of a WL donor and a RIR recipient produced W‐bearing sperm more efficiently than the reverse combination.