Biomass allocation and nitrogen limitation in a Cryptomeria japonica plantation chronosequence

We investigated soil net nitrogen mineralization rate, above- and belowground biomass allocation, and nitrogen use in a Cryptomeria japonica plantation chronosequence. Total biomass accumulation showed an asymptotic accretion pattern, and the peak total biomass accumulation rate occurred approximately 30 years after afforestation. Soil net nitrogen mineralization rate was lowest 30 years after afforestation. Between years 30 and 88, net nitrogen mineralization increased again. These results indicate that an imbalance in soil nitrogen supply and plant nitrogen demand occurred approximately 30 years after afforestation. Furthermore, leaf nitrogen concentration, which was used as an index of plant nitrogen status, was lower in mature forest than in young forest, suggesting that mature stands did not take up nitrogen as successfully. If soil resources such as nitrogen limit plant growth, plants may increase biomass allocation to fine root structure; however, fine root biomass was not higher in 30- and 88-year-old stands than in younger stands, suggesting that changes in biomass allocation may not be effective against nitrogen deficiency in a C. japonica plantation chronosequence.     

Clonal variation in heartwood norlignans of <Emphasis Type="Italic">Cryptomeria japonica</Emphasis>: evidence for independent control of agatharesinol and sequirin C biosynthesis

• Introduction   

In Cryptomeria japonica, heartwood properties are considered to be affected by specific extractives. It remains unclear whether traits of specific heartwood compounds are under genetic control.     

Decontamination of Cs from Japanese cedar (<Emphasis Type="Italic">Cryptomeria japonica</Emphasis>) via kraft cooking

To investigate the possibility of decontaminating ¹³⁷Cs-contaminated Cryptomeria japonica wood, kraft pulping was conducted and the Cs behavior in the reaction process was examined. ¹³³Cs-treated or ¹³⁷Cs-contaminated bark, sapwood, and heartwood chips of Cryptomeria japonica were digested using an aqueous solution of NaOH and Na₂S. The pulp was washed with ultrapure water and filtered, after which the filtrate (black liquor) was collected. The black liquor was acidified to separate the supernatant and precipitation. The Cs (¹³³Cs and ¹³⁷Cs) concentrations in the chip and reaction products were measured. As for wood samples, the majority of Cs was present in black liquor, while only a minor amount of Cs was retained in the pulp (<1%). In the case of bark, although the majority of Cs was present in the black liquor, the proportion of Cs in the pulp was much higher than that in the wood pulp. In addition, the Cs in the precipitation of the bark was higher than that in the wood, possibly because the Cs in the bark was combined with some components, which is insoluble in alkaline solution. Our results suggest that ¹³⁷Cs-contaminated Cryptomeria japonica wood can be used in the pulp and paper industries.     

Chilling-injury in cucumber fruits. I. Effects of storage temperature on symptoms and physiological changes

Cucumber fruits transferred to a warm temperature after chilling displayed various symptoms of chilling-injury. In cucumbers chilled to 0°C, vertical fine wrinkles and/or shallow pitting was observed, while after chilling to 5°C deep pitting and/or surface depressions were apparent. Moreover, in the 0°C fruit compared with 5°C fruit, a higher $\text{210}\text{264}$ mμ UV absorption ratio of leakage substances during chilling was observed. These results suggest that the causes of chilling-injury in the 0°C and 5°C fruit are distinct from one another. Weight loss after chilling, the amount of leakage substances, the exudate content from the cut surface of the fruit, redox potential, titratable acidity and respiratory activity were also checked after periods of chilling of 3 to 15 days.     

The toxicity of ochratoxin to ruminants.

Among the mold toxins the most toxic ochratoxin, ochratoxin A, commonly occurs in many grains, other feedstuffs, and in soil but in low concentrations. The amount required to produce acute toxicity in ruminants makes such occurrences unlikely. Toxic effects are more likely to occur in chronic low-level intoxication. The lethal single oral dose in cattle is high, probably being a few milligrams more than 13 mg/kg. The lethal level produced by repeated feeding to goats was 3 mg/kg. Ochratoxin A occurred in cows milk and urine but only when massive doses were ingested. Abortion or fetal death, though occurring in rodents, are unlikely to be induced in cattle.     

Cross-reactive antibodies to BLV and HTLV in bovine and human hosts with retrovirus infection

Sera of 22 cattle naturally infected with bovine leukemia virus (BLV), of 2 calves vaccinated with BLV, and of 22 patients with human T cell leukemia virus type I (HTLV-I) infection were tested to BLV and HTLV-I by enzyme-linked immunosorbent assay (ELISA) and Western blotting (WB). Sera of 22 healthy cattle and from 22 healthy persons, and mouse monoclonal antibody to BLV-gp51, to HTLV-I-p24, or to HTLV-I-p19 were also tested. Sera of virus-infected hosts gave significantly higher ELISA values than sera of healthy donors to both BLV and HTLV-I. The correlation between ELISA values of bovine sera to BLV and those to HTLV-I was r = 0.76, whereas that of human sera was r = 0.35. By WB and competitive WB assays, bovine sera that were ELISA-positive to BLV reacted with one or more of p12, p15, and p24 of BLV, and with only p24 of HTLV-I. Human sera that were ELISA-positive to HTLV-I reacted with p12 and p24 of BLV, and with one or more of p12, p15, p19, and p24 of HTLV-I. These results demonstrate that BLV and HTLV-I are capable of evoking cross-reactive immune response in at least some hosts under natural infection as well as by virus vaccination.     

Modification of a colorimetric analysis for lignin and its use in studying the inhibitory effects of lignin on forage digestion by ruminal microorganisms

The colorimetric acetyl bromide soluble lignin (ABSL) procedure was modified to use for analyzing intact alfalfa and its cell wall fractions for both lignin and total phenolic substances. A purified lignin extracted from alfalfa (native lignin) was used as a standard. Soluble phenolic compounds present in alfalfa did not inhibit cellulose digestion in vitro, because cell wall fractions had the same or slightly lower cellulose digestibility values than did the intact forage (intact forage = 46.5%; Morrison's cell walls = 46.4%; NDF = 42.6%; ADF = 48.7%). Disappearance of ABSL from the solid digesta was very high for intact alfalfa (48.5%), presumably reflecting either solubilization or utilization of the phenolics. However, very little ABSL was detected in the liquid fraction, suggesting that the soluble phenolic substances possibly were metabolized or modified by ruminal microorganisms. On the other hand, little, if any, of the ABSL present in the cell wall fractions disappeared after 48 h of fermentation. These data emphasize the resistance of core lignin to microbial degradation in short-term anaerobic fermentations.     

A monoclonal antibody‐based ELISA for the analysis of the insecticide flucythrinate in environmental and crop samples

A competitive enzyme‐linked immunosorbent assay (ELISA) has been developed for the detection of the insecticide flucythrinate in environmental and food samples. Two types of haptens, the acid moiety that is the hydrolyzed product of flucythrinate, and the carboxylated propyl derivative of the alcohol moiety, were used to prepare monoclonal antibodies (MAbs). Five MAbs, which raised against the former hapten, were reactive with flucythrinate. Among them, MAb F1A27‐4 showed the highest activity toward flucythrinate, and did not cross‐react with other pyrethroids such as cycloprothrin, fenvalerate, fluvalinate, etofenprox and silafluofen. The assay conditions of indirect competitive ELISA with MAb F1A27‐4 were studied to optimize the detection of flucythrinate in environmental and food samples. Incubation at 4 °C in the assay buffer, pH 8, with 300 mM sodium chloride improved the sensitivity. The addition of rabbit serum albumin or rabbit antiserum and the presence of 50 ml litre^?1 of methanol reduced matrix effects of the samples. Under optimized conditions, the ELISA detected flucythrinate spiked in water, soil, and extracts of apple and tea samples down to 10 mg litre^?1, 0.2 mg litre^?1, 0.3 mg litre^?1 and 0.3 mg litre^?1, respectively. The mean recovery and CV ranged from 91% to 120% and from 5% to 12%, respectively. The ELISA results in apple samples correlated well with those from LC–MS analysis (r² = 0.99, n = 12). © 2001 Society of Chemical Industry     

Large-area three-dimensional molecular ordering of a polymer brush by one-step processing

Rational molecular design and processing, enabling large-area molecular ordering, are important for creating high-performance organic materials and devices. We show that, upon one-step hot-pressing with uniaxially stretched Teflon sheets, a polymer brush carrying azobenzene-containing mesogenic side chains self-assembles into a freestanding film, where the polymer backbone aligns homeotropically to the film plane and the side chains align horizontally. Such an ordered structure forms through translation of a one-dimensional molecular order of the Teflon sheet and propagates from the interface macroscopically on both sides of the film. The resultant wide-area bimorph configuration allows the polymer film to bend rapidly and reversibly when the azobenzene units are photoisomerized. The combination of polymer brushes with hot-pressing and Teflon sheets provides many possibilities in designing functional soft materials.     

Ecological studies of Yersinia enterocolitica. II. Experimental infection with Y. enterocolitica in pigs

Fattening pigs were inoculated with the human pathogenic strains of Yersinia enterocolitica, biovar 4 serovar 3 phagovar 8 and biovar 2 serovar 5.27. Each pig received 2.6 × 10⁹ organisms by catheter into the stomach and thereafter 10% sodium bicarbonate solution, by the same route. The serovar 3 strain became established in the intestines of four out of six 11-week-old pigs and in all three 24-week-old pigs. Serovar 5.27 established in the intestines of all four 10-week-old pigs. In these pigs, both serovars were excreted in the feces at 10²?10⁶ cells g^?1 for a few weeks. However, the serovar 5.27 was excreted in the feces at less than 10^3·3 cells g^?1 for 2 weeks by 24-week-old pigs. Horizontal transmission with the serovar 5.27 strain was observed on the 5th–11th day, and the bacteria were present in the intestines during the 2nd week. However, the serum titers to O-agglutinin were 1/10 and less, but in one pig, the titer was 1/40 against serovar 5.27 strain.