Susceptibilities of some aquatic ferns to paddy herbicide bensulfuron methyl

Paddy herbicides have the potential to cause adverse effects on non-target plants. Susceptibilities of some aquatic ferns ( Azolla japonica Franch. et Savat., Isoetes japonica A. Braun, Marsilea quadrifolia L. and Salvinia natans All.) and duckweeds ( Lemna minor L. and Spirodela polyrhiza Schleid.) to paddy herbicide bensulfuron methyl (BSM) were evaluated with a 20 day exposure experiment using 200 cm² pots. The BSM concentrations in the surface water of monitoring pots with no plants dissipated exponentially with half lives of 3.5 and 3.9 days at application rates of 15 and 150 g ha⁻¹, respectively. The BSM concentrations in the surface water 1 day after application in the culture pots were comparable among plant species, and were lower than those in the monitoring pots. Bensulfuron methyl reduced the plant growth in all species. I . japonica showed the lowest intrinsic relative growth rate (RGR) and the lowest susceptibility with an effective dose resulting in 50% growth inhibition (ED₅₀) of 21 g ha⁻¹. Except for I . japonica , the RGR of the duckweeds was similar to the ferns, and ED₅₀ for the duckweeds was higher than the ferns. ED₅₀ for Sa . natans , A . japonica and M . quadrifolia were 1.1, 1.8 and 1.2 g ha⁻¹, respectively, which were smaller than 1/20 of the recommended field dose (51–75 g ha⁻¹) and ranged from 1/2 to 1/6 of ED₅₀ for L . minor and Sp . polyrhiza (6.5 and 3.2 g ha⁻¹, respectively). These results suggest that BSM application in paddy fields and its runoff in some localities is expected to have adverse effects on the growth of Sa . natans , A . japonica and M . quadrifolia .     

Investigations on the radioactive contamination of crop plants as a result of H-bomb detonation (Part 2) Root and foliage uptake of “Bikini ash”

The Foliar Uptake by Squash Plant

The radioactive ash for experimental use, hereafter referred to as “Bikini ash”, was prepared by igniting the heavily contaminated substances on board No. 5 Fukuryu Maru at about 650°C, followed by sifting through a 100 mesh sieve. On ignition some parts of the fission products, particularly iodine, ruthenium and tellurium would have possibly been lost to the air.     

Effects of acid extracts of tomato (Lycopersicon esculentum Mill.) and carrot (Daucus carota L.)wastes from the food industry on the growth of some crops and weeds

The effects of acid extracts of tomato ( Lycopersicon esculentum Mill.) and carrot ( Daucus carota L.) juice wastes from the food industry on the growth of five species of crops and four weeds were examined. The acid extract of the tomato juice waste promoted the shoot and root growth of tomato, Chinese cabbage, corn, and radish, but not the growth of oat seedlings. The extract did not promote the shoot growth of weeds tested, and it inhibited the root growth of the weeds that included barnyardgrass ( Echinochloa oryzicola Ohwi), southern crabgrass ( Digitaria ciliaris Koel.) and Japanese barnyard millet ( Echinochloa utilis Ohwi). The carrot juice waste was also examined as another waste from the food industry. The effect of the acid extract of carrot juice waste showed significant promoting effects on the root growth of Chinese cabbage; however, the effects on other plants were lower than that of tomato juice waste. It also did not inhibit the growth of weeds. These results suggested that the acid extract from tomato juice waste is useful as plant-growth substances because they have a promoting effect on the shoot and root growth of crops, and an inhibitory effect on the root growth of some weeds.     

Distribution of mecA-harboring staphylococci in healthy mares

The prevalence of staphylococci that harbor the mecA gene responsible for methicillin resistance was examined in healthy breeding mares. Staphylococci often cause diseases of horses such as metritis, keratitis, and abscess. Methicillin-resistant staphylococci would make antibiotic treatments ineffective, so it may be significant to know the distribution of mecA-harboring staphylococci in mares. Isolation of mecA-harboring staphylococci was achieved from nares and pasterns of 100 mares in Hokkaido, Japan. From 13% of the mares, mecA-harboring staphylococci, including 15 isolates of Staphylococcus sciuri and 3 of Staphylococcus lentus, were isolated. Isolates of S. sciuri were found to be genetically polyclonal by pulsed-field gel electrophoresis. These isolates produced no PCase and showed low or no resistance to beta-lactam and other classes of antibiotics. Distribution of staphylococcal species and levels of antibiotic resistance were found to be different between isolates from the present mares and those previously reported from riding-horses. Antibiotic pressure may lead to these differences. In addition, it appears that mecA-harboring S. sciuri may be native to horses.     

Sorption of Cr(VI) on the wood of Japanese larch treated with concentrated sulfuric acid

A carbonaceous sorbent was prepared from the wood of Japanese larch (Larix leptolepis) by dehydration with concentrated sulfuric acid in a 69% yield. The abilities of the sorbent to remove Cr(VI) from aqueous solutions were investigated. Research parameters included the initial solution pH, temperature, and initial concentration of Cr(VI) in solution. The removal of Cr(VI) was highly solution pH dependent and was mainly governed by physicochemical sorption under weak acidic conditions. The equilibrium data fit well in the Langmuir isotherm model. The Langmuir constants were calculated at different temperatures, and the sorption capacity increased with rising temperature, indicating the endothermic nature of the Cr(VI) sorption onto the sorbent. The desorption experiments suggest that the Cr(VI) sorption is generally irreversible, owing to strong interaction of HCrO ₄ ⁻ with the active sites of the sorbent.     

Simple method for synthesizing phenolicβ-O-4 dilignols

A modified synthetic method for phenolic-O-4 lignin substructure model dimers was developed involving protection of the phenolic hydroxyl group of acetophenons with benzoyl chloride, bromination with 4-dimethylaminopyridiniumbromide perbromide, condensation with phenols in the presence of 18-crown-6-ether, condensation with paraformaldehyde, reduction with NaBH₄ and debenzoylation. This method results in shorter reaction times and increasing yields without the application of strict anhydrous and drastic conditions or chloric solvents. This alternative route could be applied to the-O-4 dilignol syntheses of four combinations of guaiacyl and syringyl derivatives.     

Effect of ovarian hormones on maturation of dendritic cells from peripheral blood monocytes in dogs

Previously, we reported that ovarian hormones affect the immune response against E. coli isolated from the dogs affected with pyometra. In order to investigate mechanisms underlying the immune modulation, we examined the effects of ovarian hormones on the generation of dendritic cells (DCs), the most potent antigen presenting cell. DCs were differentiated from peripheral blood monocytes (PBMOs) using a cytokine cocktail. Both estrogen receptor and progesterone receptors were expressed by the PBMOs and immature DCs. When various ovarian hormones were added to the culture for the DC differentiation, progesterone significantly decreased the expression of DC maturation markers, such as CD1a, CD80 and CD86, on mature DCs. Conversely, the addition of estrogen to the cultures increased the expression of CD86, but not other maturation makers. Furthermore, DCs differentiated in the presence of progesterone did not stimulate allogeneic mononuclear cells in PB. Taken together, these results indicate that progesterone diminishes the maturation of DCs, leading to decreased immune responses against invading pathogens.