Column Experiment on Nitrate Purification with Polylactic Acid and Iron Powder

Groundwater contamination by nitrates is a worldwide problem, but to date there have been no effective measures to purify contaminated groundwater. If a denitrifying system can be constructed in aquifers, it will be able to purify groundwater in situ. This purifying system should also be maintenance free. The purpose of our work is to construct a maintenance-free denitrification system for in situ groundwater purification. This paper presents the result of a basic study on a maintenance-free denitrification system using biodegradable plastic and iron powder. A biodegradable plastic (polylactic acid, PLA) and iron powder were used as detergents, and the nitrate-contaminated groundwater was injected from the bottom of a packed silica sand column filled with a mixture of the detergents. Laboratory experiments were carried out, varying factors such as molecular weight of the biodegradable plastic and mixing ratio of the detergents. Water that permeated through the purification column was sampled to determine the decrease in nitrate concentration. The experimental results suggest that a combination of PLA and iron powder seems effective for denitrification, and that the rate of the PLA degradation is closely related to the molecular weight of the PLA and iron powder content. In this case iron powder acts as accelerator in denitrification. It is concluded that a maintenance-free denitrification system can be built, using PLA and iron powder as detergents. The proposed system may also be used in a wide range of nitrate contamination conditions, adjusting the molecular weight of the PLA and the mixing ratio of the detergents.     

Myoclonus and hypersensitivity of the hind limbs and tail with urinary retention following neuraxial administration of morphine in a cat

An adult female domestic shorthair cat developed myoclonus, muscle rigidity, and hypersensitivity of the hind limbs and tail with urinary retention following neuraxial administration of morphine. Myoclonic contractions resolved following treatment with midazolam and a urinary catheter was placed until normal micturition returned. The cat was clinically normal 36 hours after neuraxial morphine injection. The cat underwent a second surgery without neuraxial morphine and control of postoperative pain required more intervention.Key clinical message:Neuraxial morphine may cause myoclonus and urinary retention. The response to pharmacological treatment of myoclonus is varied, but a benzodiazepine drug may be effective.     

Distribution of photoperiod-insensitive alleles Ppd-B1a and Ppd-D1a and their effect on heading time in Japanese wheat cultivars

The genotypes of photoperiod response genes Ppd-B1 and Ppd-D1 in Japanese wheat cultivars were determined by a PCR-based method, and heading times were compared among genotypes. Most of the Japanese wheat cultivars, except those from the Hokkaido region, carried the photoperiod-insensitive allele Ppd-D1a, and heading was accelerated 10.3 days compared with the Ppd-D1b genotype. Early cultivars with Ppd-D1a may have been selected to avoid damage from preharvest rain. In the Hokkaido region, Ppd-D1a frequency was lower and heading date was late regardless of Ppd-D1 genotype, suggesting another genetic mechanism for late heading in Hokkaido cultivars. In this study, only 11 cultivars proved to carry Ppd-B1a, and all of them carried another photoperiod-insensitive allele, Ppd-D1a. The Ppd-B1a/Ppd-D1a genotype headed 6.7 days earlier than the Ppd-B1b/Ppd-D1a genotype, indicating a significant effect of Ppd-B1a in the genetic background with Ppd-D1a. Early-maturity breeding in Japan is believed to be accelerated by the introduction of the Ppd-B1a allele into medium-heading cultivars carrying Ppd-D1a. Pedigree analysis showed that Ppd-B1a in three extra-early commercial cultivars was inherited from ‘Shiroboro 21’ by early-heading Chugoku lines bred at the Chugoku Agriculture Experimental Station.     

Changes in esculeoside A content in different regions of the tomato fruit during maturation and heat processing

We previously demonstrated that esculeogenin A, a new aglycone of the tomato sapogenol esculeoside A, inhibits both acyl coenzyme A:cholesterol acyl-transferase (ACAT)-1 and -2 and ameliorates the pathogenesis of atherosclerosis in apoE deficient mice. Although we believe that daily intake of esculeoside A from tomato products can play a beneficial role in preventing the pathogenesis of atherosclerosis, the compound is not being used for preventive medicine due to the lack of information on methods for quantitative analysis and the content and stability of the compound in tomato products. In the present study, we report the development of a high-performance liquid chromatography (HPLC) method using an instrument equipped with a refractive index (RI) detector for esculeoside A quantification. We used this method to measure the changes in esculeoside A content during maturation, its distribution in the fruit body, and its stability during the heating process. The contents of esculeoside A in cherry tomatoes and Momotaro tomatoes were 21- and 9-fold, respectively, higher than that of lycopene, which is the most well-known compound in tomatoes. Furthermore, the esculeoside A content in pericarp wall was higher than in the whole tomato fruit and increased in a time-dependent manner during maturation. Although the melting point of purified esculeoside A was 225 °C, the esculeoside A in crude tomato extract decreased in a temperature-dependent manner. Degradation due to the heating process was inhibited under a pH of 9. These results demonstrated that the esculeoside A content differs in the various types of tomatoes, during maturation, and during the heating process used for preservation.     

Wood friction characteristics during exposure to high pressure: influence of wood/metal tool surface finishing conditions

Friction that arises during processing for the deformation of wood under relatively high pressure levels (ca. >1 MPa) is an important factor to be taken into account when wood is processed. However, few studies on such friction have been published. The present study was undertaken to evaluate the influence of surface finishing conditions on the nominal friction coefficient (μ) of the wood and metal tool surfaces. Sticking friction was likely to arise on a relatively coarse metal surface, and the type of metal tool surface finishing was found to have large impact on the friction mechanism. The friction characteristics during exposure to high pressure seem to be affected not only by the interface contact characteristics, but also by the deformation characteristics of wood during compressive load or measurement. The value of μ on water-saturated wood was equal or higher than that on dry wood, which suggests that the contact characteristics between these two types of wood are significantly different. The water content in wood was shown to affect both the interface contact and deformation characteristics of wood. The value of μ was not significantly affected by the wood surface finishing conditions; however, changes in μ during sliding differed slightly, depending on the finishing conditions.     

Pulse-labelling trees to study carbon allocation dynamics: a review of methods, current knowledge and future prospects

Pulse-labelling of trees with stable or radioactive carbon (C) isotopes offers the unique opportunity to trace the fate of labelled CO(2) into the tree and its release to the soil and the atmosphere. Thus, pulse-labelling enables the quantification of C partitioning in forests and the assessment of the role of partitioning in tree growth, resource acquisition and C sequestration. However, this is associated with challenges as regards the choice of a tracer, the methods of tracing labelled C in tree and soil compartments and the quantitative analysis of C dynamics. Based on data from 47 studies, the rate of transfer differs between broadleaved and coniferous species and decreases as temperature and soil water content decrease. Labelled C is rapidly transferred belowground-within a few days or less-and this transfer is slowed down by drought. Half-lives of labelled C in phloem sap (transfer pool) and in mature leaves (source organs) are short, while those of sink organs (growing tissues, seasonal storage) are longer. (13)C measurements in respiratory efflux at high temporal resolution provide the best estimate of the mean residence times of C in respiratory substrate pools, and the best basis for compartmental modelling. Seasonal C dynamics and allocation patterns indicate that sink strength variations are important drivers for C fluxes. We propose a conceptual model for temperate and boreal trees, which considers the use of recently assimilated C versus stored C. We recommend best practices for designing and analysing pulse-labelling experiments, and identify several topics which we consider of prime importance for future research on C allocation in trees: (i) whole-tree C source-sink relations, (ii) C allocation to secondary metabolism, (iii) responses to environmental change, (iv) effects of seasonality versus phenology in and across biomes, and (v) carbon-nitrogen interactions. Substantial progress is expected from emerging technologies, but the largest challenge remains to carry out in situ whole-tree labelling experiments on mature trees to improve our understanding of the environmental and physiological controls on C allocation.     

Seasonal variation in Campylobacter-contaminated retail chicken products: a year-round investigation in Japan

Campylobacter was isolated from retail meat samples collected during the fiscal year 2009 in Japan. The higher percentages of contamination of chicken products were observed from June (39.3%) to November (83.3%). However, the highest number of human campylobacteriosis cases was reported in June in the Infectious Agents Surveillance Report. The chicken isolates with distinct clusters IVb and I, based on the restriction fragment length polymorphism of the flaA gene, were predominantly obtained during the periods between April and November 2009 and between February and March 2010, respectively. Extensive monitoring of Campylobacter contamination in chickens produced in various places is needed to analyse the seasonal variations between contamination of the meat products and the number of human cases with campylobacteriosis.     

Maternal exposure to low doses of DES altered mRNA expression of hepatic microsomal enzymes in male rat offspring

Our previous studies demonstrated that prenatal diethylstilbestrol (DES) treatment disrupts steroidogenesis but induces high-level expression of androgen receptor (AR) mRNA to inhibit the disruption of spermatogenesis. This study examined which prenatal DES treatment influenced hepatic microsomal enzymes, CYP3A1, CYP2B1/2, CYP2C11, UGT2B1 (UDP-glucuronosyltransferase 2B1), and IGF-1 (insulin-like growth factor-1), in male rat offspring. DES treatment decreased the mRNA expression levels of CYP3A1 and CYP2B1/2, but did not alter the expression of CYP2C11. At 6 weeks, DES treatment increasd the mRNA expression levels of UGT2B1 and IGF-1. These results suggest that prenatal DES treatment alters two hepatic enzymes (CYP3A1 and CYP2B1/2) and IGF-1 mRNA expression levels to counteract the low level of testosterone, but this disrupted UGT2B1 mRNA expression reduces the testosterone level.