Measurement of Fertilizer Leaching from the Root Zone Using an Automated Infiltration Soil Water Sampler in an Unsaturated Sandy Field

In sandy fields with vegetable cultivation, fertilizer leaching may occur and it should be well-controlled. The development of a direct soil water sampler is necessary to examine solute transport and fertilizer leaching in the vadose zone, since soil water reflects timely monitoring of data more accurately than groundwater. We developed a Suction-Controlled Flux Sampler to collect infiltration soil water in a sandy soil. In the present study, we monitored fertilizer leaching in an unsaturated sandy field during the rainy season, while evaluating the sampling performance of SCFS for the sampling of infiltration water. SCFS directly collected the infiltration water effectively over a period of several months in the sandy field and recorded the Water-Collecting Efficiency from 92 to 115% under various infiltration conditions during a period of 50 d. WCE was affected by the rainfall intensity as well as by previous rainfall, which enhanced WCE. The results obtained from the use of SCFS and several sensors demonstrated that the amount of leached water remained low as long as irrigation was applied according to the cultivation manual. However, an unexpected heavy rainfall event led to fertilizer leaching. The fertilizer leaching trend was effectively monitored by several sensors inserted into the soils, while detailed analysis of the components was performed after collection by using SCFS. Direct access to infiltration water enabled to examine the infiltration process and detailed variations in the amounts of discharged anions. The sensor-equipped monitoring system together with SCFS is suitable for precise management of fertilizer and irrigation application.     

Precipitation chemistry in Japan 1989–1993

Precipitation chemistry in Japan was discussed on a wet-only sample database obtained in a nationwide survey from April 1989 to March 1993. Wet-only samples were collected at 29 stations over Japan on a biweekly basis. Commonly determined chemical parameters were measured in laboratories. The volume-weighted annual mean pH at each site ranged from 4.50 to 5.83 with a mean of 4.76. Concentration ranges and means (parenthesized) on an equivalent basis for major ions were as follows: nss-SO₄ ^2–; 5.2–58.9 (38.6), NO₃ ^–; 1.8–25.0 (14.1), NH₄ ⁺; 0.55–29.8 (18.3), nss-Ca²⁺; 2.0–34.5(14.2), Na⁺; 6.4–275.3 (49.1), Cl^–; 13.7–322.4 (63.5) eq L^–1. Acid-base relationships for Phase-II records were quantitatively discussed in terms of three measures: pH, fractional acidity, and our proposed pA_i.     

Effects of Ca2+ and sulfhydryl reductant on the polymerization of soybean glycinin catalyzed by mammalian and microbial transglutaminases

Two types of transglutaminases (TGases), Ca(2+)-dependent TGase derived from guinea pig liver (GTGase) and Ca(2+)-independent TGase derived from a variant of Streptoverticillium mobaraense (MTGase), were used to study the cross-linking of soybean 11S globulin (glycinin). The effects of sulfhydryl reductant (dithiothreitol, DTT) and Ca(2+) on the conformation and TGase-catalyzed polymerization of glycinin were investigated. The conformational change of glycinin was probed by spectral methods. The degree of cross-linking and the polymer (aggregate) formation were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and dynamic light scattering, respectively. Addition of DTT stimulated the TGase-catalyzed cross-linking reactions without destroying the secondary and tertiary structure of glycinin but did not influence the polymer or aggregate formation. It was found that Ca(2+) caused the formation of larger size polymers at lower concentrations, while it suppressed the polymerization at higher concentrations. In addition, the cross-linking behaviors of glycinin were shown to be different between MTGase- and GTGase-catalyzed systems.     

Pathological studies on central nervous tissues of rats infected with Rattus serotype hantavirus (SR-11 strain).

Newborn rats inoculated intraperitoneally with a hantavirus strain (SR-11) developed neurological signs such as ataxia and limb paralysis. The main histological lesions were scattered and multiple neuronal degeneration and necrosis with eosinophilic cytoplasmic inclusion bodies (CIB) in the brain, spinal cord and ganglia. Immunohistochemically, the viral antigen was detected in neurons, capillary endothelial and glial cells throughout the nervous tissue and CIB were identified as consisting of hantaviral antigen (nucleocapsid protein). Ultrastructurally, CIB in the neurons consisted of an accumulation of granular or filamentous materials, or both. They were seen near a well-developed Golgi apparatus and associated with well-developed rough endoplasmic reticulum and increased numbers of ribosomes. The present results suggested that this virus strain was highly infective in neurons of the newborn rats and that excess production of viral antigen which accumulated as CIB resulted in the neuronal changes.     

Precise, simple screening for resistance in potato varieties to common scab using paper pots

Resistance to common scab pathogen Streptomyces turgidiscabies of seven potato varieties was compared in the field with a newly developed paper pot method. Seedlings raised in soil in paper pots containing inocula at 1 × 10³ to 10⁷cfu/g soil were transplanted into a scab-free field and grown for 3 months. The disease severity of the seven varieties in the field trials differed in iteration and from year to year, even though their resistance levels were approximately similar at the expected levels. With the paper pot method, the seven varieties had different resistance levels, which were almost completely consistent with the results of the field trials, at more than 1 × 10⁵cfu/g soil. Significant differences in disease severity between resistant and susceptible varieties were observed (P = 0.05) for 2 years, and the resistance level of the varieties was elucidated.     

Expression and purification of recombinant swine interleukin-4

The swine interleukin-4 (SwIL-4) cDNA was cloned by RT-PCR. It was expressed using an expression vector pQE30 in E. coli, a baculovirus AcNPV vector pVL1392 in insect cells, and a pCAGGS vector in mammalian cells. The rSwIL-4 proteins expressed from bacteria and insect cells were purified using a chelating affinity column and a mAb-coupled immunoaffinity column. The amount of the products and their bioactivities were compared. All recombinant cytokines were efficiently reacted with the specific antibodies and the molecular weight of rSwIL-4 was approximately 16 kDa in E. coli, 15 and 18 kDa in insect cells, and 15 and 20 kDa in mammalian cells. Variations of molecular weight observed in insect and mammalian cells were probably due to different modification ways of glycosylation. All these recombinant proteins retained their antigenicity and were biologically active in inducing human TF-1 cell proliferation in vitro. The simple purification method will make it possible to evaluate the in vitro and in vivo effects of IL-4 in pigs.     

The effect of recombinant swine interleukin-4 on swine immune cells and on pro-inflammatory cytokine productions in pigs

The in vitro effect and the in vivo influence of recombinant swine IL-4 (rSwIL-4) were characterized in various swine cells and in nursery pigs on LPS-induced endotoxic shock and pro-inflammatory cytokine productions. In in vitro experiment, the rSwIL-4 induced a proliferation of CD4 positive T cells in mitogen-prestimulated peripheral blood mononuclear cell (PBMC). In addition, the rSwIL-4, which was produced from insect cells, promoted the differentiation of monocytes into immature dendritic cells in combination with granulocyte macrophage-colony stimulating factor (GM-CSF). Furthermore, the rSwIL-4 successfully suppressed the LPS-induced secretion of TNF-alpha, IL-1alpha, IL-6, IL-8, and IL-18 from swine alveolar macrophages when rSwIL-4 was treated at the same time with LPS. In in vivo experiment in nursery pigs, subcutaneous pretreatment of rSwIL-4, which was produced from baculovirus expression system, enhanced the severity of respiratory failure with endotoxic shock, and increased the production of TNF-alpha and IL-18 in response to inoculation with LPS. These results indicate that the rSwIL-4 is biologically active in both in vitro and in vivo treatments. Depending on the administration time, pro-inflammatory cytokine productions by IL-4 can cause either inhibitory or stimulatory regulation.