Evaluating vegetation recovery following large-scale forest fires in Borneo and northeastern China using multi-temporal NOAA/AVHRR images

This study evaluated whether a normalized difference vegetation index (NDVI), derived from 8-km-resolution National Oceanic Atmospheric Administration (NOAA) Pathfinder AVHRR (advanced very high resolution radiometer) land (PAL) data, is appropriate for monitoring recovery following large-scale forest fires. Recovery processes were examined after fires on the island of Borneo and in northeastern China in 1983 and 1987, respectively. Based on pre- and post-fire NDVI differences (NDVId), six damage classes were established. Post-fire changes in land cover were monitored using (1) the average NDVI of all pixels corresponding to each damage class (A-NDVI) and (2) the ratio of a fire-affected A-NDVI to a non-fire-affected A-NDVI (QNDVI). Burn areas located by an NDVId threshold value were similar to reported burn areas. Both A-NDVI and QNDVI values signaled vegetation recovery, but the QNDVI gave much better results. For both the 1983 Borneo and 1987 northeastern China fires, QNDVI values dropped at the time of the fire and increased for about 4 years afterwards, although a 4-year period is obviously less than the time required for biomass recovery. Trends at the two study sites diverged after this period, however. The QNDVI values for multiple fire events in Borneo (in 1983, 1987, 1991, 1997, and 1998) showed that recovery times varied with the size of the burn area, but not with the damage class of the same event, whereas the severe-class QNDVI values for the fire in northeastern China in 1987 were still lower than the control value 10 years after the fire.     

Inhibitory effects of cucurbitane glycosides and other triterpenoids from the fruit of Momordica grosvenori on epstein-barr virus early antigen induced by tumor promoter 12-O-tetradecanoylphorbol-13-acetate

Two new triterpene benzoates, 5-dehydrokarounidiol dibenzoate (1) and karounidiol dibenzoate (2), and two new triterpene glycosides, 5alpha,6alpha-epoxymogroside IE(1) (8) and 11-oxomogroside A(1) (9), along with 15 known triterpenoids (one triterpene benzoate, 3; three triterpene mono-ols, 4-6; one triterpene aglycon, 7; and 10 triterpene glycosides, 10-19), were isolated from the ethanol extract of the fruit of Momordica grosvenori. The structures of 1, 2, 8, and 9 were determined on the basis of spectroscopic and chemical methods. Among the known triterpene glycosides, mogroside I E(1) (12) was a new naturally occurring compound. Eighteen triterpenoids (2-19) and 11-oxomogrol (20), a hydrolysis product of 9, were evaluated with respect to their inhibitory effects on the induction of Epstein-Barr virus early antigen (EBV-EA) by 12-O-tetradecanoylphorbol-13-acetate (TPA) in Raji cells, which is known to be a primary screening test for antitumor promoters. All of the compounds tested showed potent inhibitory effects on EBV-EA induction (70-100% inhibition at 1 x 10(3) mol ratio/TPA).     

Survey of coccidial oocysts and parasite eggs in feces of free-ranging Grus japonensis

Fecal survey of Eimeria oocysts and parasite eggs was conducted for 219 fecal samples of free-ranging Grus japonensis in Kushiro district in Hokkaido in April 2003. Positive rate and mean oocysts (or eggs) per gram in positive samples were 26% (57/219) and 8.8 (0.2-136) in oocysts of Eimeria reichenowi, 18.3% (40/219) and 320 (100-1,000) in trematode eggs, 0.1% (2/219) and 0.2 (0.2-0.3) in eggs of Nematoda A, and 4.1% (9/219) and 0.8 (0.2-3.6) in eggs of Nematoda B, respectively.     

Effect of forest structure on the spatial variation in soil respiration in a Bornean tropical rainforest

This study was undertaken to identify critical and practical factors explaining spatial variations in soil respiration and to estimate stand-scale soil respiration in an aseasonal tropical rainforest on Borneo Island. To this aim, we conducted soil respiration measurements at 25 points in a 40 m × 40 m subplot of a 4 ha study plot between 2002 and 2006, and examined the spatial variation in soil respiration averaged over the 4 years in relation to soil, root, and forest structural factors. In addition, we examined the spatial representativeness of soil respiration measured in the subplot using a specific scaling procedure. Consequently, we found significant positive correlation between the soil respiration and forest structural parameters such as the mean diameter at breast height (DBH), total basal area, and maximum DBH within 6 m of the measurement points. The most important factor was the mean DBH within 6 m of the measurement points, which had a significant linear relationship with soil respiration. Using the derived linear regression and an inventory dataset, we estimated the 4 ha plot-scale soil respiration. The 4 ha plot-scale estimation (6.0 μmol m⁻² s⁻¹) was nearly identical to the subplot-scale measurements (5.7 μmol m⁻² s⁻¹), which were roughly comparable to the nocturnal CO₂ fluxes calculated using the eddy covariance technique. In addition, we discuss characteristics of the stand-scale soil respiration at this site by comparing with those of other forests reported in previous literature in terms of the soil C balance. Soil respiration at our site was noticeably greater, relative to the incident litterfall amount, than soil respiration in other tropical and temperate forests probably owing to the larger total belowground C allocation by emergent trees. Overall, this study suggests the arrangement of emergent trees with larger DBH and their belowground C allocation could be primary factors controlling spatial variations in soil respiration in the tropical rainforest.     

Identification of RAPD marker linked to fruit skin color in Japanese pear (Pyrus pyrifolia Nakai)

In Japanese pear, fruit skin color is a very important trait for growers because the russet skin protects the fruit against external stress caused by disease, insects, bad weather, and shipping. This report describes the development of a randomly amplified polymorphic DNA (RAPD) marker linked to major genes controlling the fruit skin color in Japanese pear. Two F₁ progenies from the cross of ‘Kousui’ × ‘Kinchaku’ and ‘Niitaka’ × ‘Chikusui’ segregated by fruit skin color were used for bulked segregant analysis. Four kinds of bulked DNA were constructed and used for the polymerase chain reaction in RAPD analysis. After 200 random primers were screened against four bulks, a band named OPH-19₄₂₅ was selected in cooperation with green bulks. The recombination rate between OPH-19₄₂₅ and the green skin phenotype was 7.3%. The RAPD marker (OPH-19₄₂₅) could select green fruit with probability as high as approximately 92%. The marker was apparently useful for the selection of green-skinned individuals in a breeding program. This is the first report on developing a DNA marker closely linked to the fruit phenotype in Japanese pear.     

Estrous cycle based on blood progesterone profiles and changes in vulvar appearance of Malayan tapirs (Tapirus indicus)

The progesterone (P(4)) profiles and macroscopic vulvar changes of female Malayan tapirs were investigated in order to understand their fundamental reproductive physiology and to search for visual indicators of estrus. Blood was collected once or twice a week from seven female Malayan tapirs kept at four zoos. Serum or plasma P(4) concentrations were determined by radioimmunoassay. The P(4) concentrations changed cyclically throughout the years, and a total of 56 cycles was confirmed in the seven females. The length of the estrous cycle based on the P(4) profiles was 43.6+/-2.0 days; however, this mean includes great variation in length, from 21 to 84 days. Mucous discharge from the vulva and vulvar swelling were seen when the P(4) concentrations were low before the beginning of a rise in most cases. In conclusion, captive female Malayan tapirs have variations of approximately 1 to 3 months in estrous cycle length, and visual changes in the vulva are helpful in estimating estrus in female Malayan tapirs.     

Effects of water temperature on feeding and growth of juvenile marbled flounder <Emphasis Type="Italic">Pseudopleuronectes yokohamae</Emphasis> under laboratory conditions: evaluation by group- and individual-based methods

To determine the optimal temperature for juvenile (0 year old) marbled flounder Pseudopleuronectes yokohamae, juveniles of 40–54 mm standard length were reared at six temperature conditions in the range of 8–26 °C, using group- and individual-based methods. Growth of juveniles increased from 8 to 20 °C but decreased from 20 to 26 °C, irrespective of the rearing method used. Food intake was greatest at 20 and 24 °C compared with other temperatures, while feed conversion efficiency was greater at 20 °C than 24 °C in individual rearing. Individual rearing provided more information such as individual variations in growth and food consumption, suggesting the importance of individual-based experiments for exploring the optimal temperature for fish.     

Effects of co‐supply ratios of swimming crab Portunus trituberculatus zoeae and Artemia on survival and growth of East Asian common octopus Octopus sinensis paralarvae under an upwelling culture system

Despite recent advances in culture technology for East Asian common octopus Octopus sinensis paralarvae using upwelling systems, securing suitable feed for the paralarvae is an unresolved issue. The zoea of the swimming crab Portunus trituberculatus is a good candidate for paralarval feed because of the high fecundity of the adult females. To investigate the effects of supplying P. trituberculatus zoeae and their feeding method on paralarvae, we cultured paralarvae with supplying different combination ratios of zoeae and Artemia (10:0, 7:3, 5:5, 3:7 and 0:10), and with or without supplementing rotifers using small‐scale (3‐L) upwelling systems. Paralarval survival rate and growth were improved when zoeae were supplied as the main feed, but reduced when the proportion of Artemia exceeded half the whole preys. Supplementing rotifers did not affect the paralarval survival and growth. Subsequently, paralarvae were cultured by supplying zoeae (partially augmented by Artemia) using three large (1‐kl) upwelling systems to assess their feeding effectiveness in juvenile octopus production. Paralarvae could be cultured at high survival rates of 77.1 ± 5.1% to reach benthic juveniles at 23 days after hatching. In conclusion, supplying P. trituberculatus zoeae augmented with Artemia under an upwelling culture system has great potential for juvenile octopus production.     

Stereochemical basis for the insecticidal activity of carbamoylated and acylated pyrazolines

Methyl 3-(4-chlorophenyl)-1-[N-(4-chlorophenyl)carbamoyl]-4-methyl-2-pyrazoline-4-carboxylate was converted to corresponding (1R)- and (1S)-phenethyl esters via its carboxylic acid and acid chloride at the C-4 atom to separate the diastereomers. Their configurations were confirmed by X-ray analysis. Both isomers of the (1R)methylbenzyl ester were subjected to transesterification with sodium methoxide to obtain enantiomers of the starting methyl ester. Their insecticidal activity was measured against American cockroaches (Periplaneta americana (L.)) by injection and against house flies (Musca domestica L.) by topical application under various synergistic conditions with metabolic inhibitors. The activity values of the four α-methylbenzyl esters and the R-isomer of the starting methyl ester were similar. The S-enantiomer of the methyl ester was about 10 and 100 times more active than the R-isomer against the cockroach and the fly, respectively. Some N-arylacetyl and N-aryloxyacetyl derivatives of the starting N-(4-chlorophenyl)carbamoyl compound gave very low activity. Conformation-energy profiles for some compounds suggested that the conformation of substituents on the N-1 atom in the pyrazoline ring has a specific role for the potential insecticidal effects.