Influence of Acid Deposition on Inland Water Chemistry - A Case Study from Hyogo Prefecture, Japan -

The Influence of acid deposition on stream and lake water chemistry was studied in a forested watershed of Hyogo prefecture, Japan. Monthly sampling of four streams, one artificial lake, and precipitation was carried out from 1995 to 2000. The pH of the monthly bulk precipitation and rainwater were ranged from 4.06 to 7.10. No trends were evident during the monitoring periods. The pH and alkalinity in the four streams, which flow into the artificial lake, ranged from 6.37 to 8.72 and 0.077 meqL^?1 to 0.485 meqL^?1, respectively. The differences in the water quality of the four streams were related to the geology of each watershed. Lower pH and alkalinity were observed during high- discharge periods. On the other hand, the pH and alkalinity of the outflow from the lake ranged from 6.47 to 7.36 and 0.195 meqL^?1 to 0.339 meqL^?1, respectively. No acidification of the aquatic environment was observed during the investigated periods. The results suggest that this forested ecosystem has the capacity to neutralize incoming acid deposition.     

Uptake by dietary exposure and elimination of aflatoxins in muscle and liver of rainbow trout (Oncorhynchus mykiss)

Uptake and elimination of aflatoxins (AFs) by rainbow trout ( Oncorhynchus mykiss ) during a long-term (21 days) dietary exposure were studied to assess contamination by AFs in aquaculture fish fed AF-containing feed. The uptake factor (UF) of aflatoxin B(1) (AFB(1)) in muscle ranged from 0.40 × 10(-3) to 1.30 × 10(-3). AFB(1) concentrations in liver were 165-342 times higher than in muscle. AFs from feed were more highly accumulated in liver than in muscle. Aflatoxicol (AFL) and aflatoxin M(1) (AFM(1)) were detected in muscle and liver and also in the rearing water. AFL concentrations were higher than AFM(1) by 2 orders of magnitude in muscle, and AFL was a major metabolite of AFB(1). The elimination rate constants (α) of AFB(1) and AFL in muscle (1.83 and 2.02 day(-1), respectively) and liver (1.38 and 2.41 day(-1), respectively) were very large. The elimination half-life (t(1/2)) of AFB(1) was 0.38 days (9.12 h) in muscle and 0.50 days (12.00 h) in liver. The elimination half-life of AFL in muscle and liver was 0.34 day (8.16 h) and 0.29 day (6.96 h), respectively. These data show that AFs are eliminated rapidly and are not biomagnified in fish. Thus, AFB(1) concentration in muscle of fish fed AFB(1)-containing feed (ca. 500 μg/kg) decreased to below the detection limit (20 ng/kg) of the most sensitive analytical method at 1.54 days (36.96 h) after the change to uncontaminated feed.     

Guar foaming albumin: a low molecular mass protein with high foaming activity and foam stability isolated from guar meal

The water extract of guar meal ( Cyamopsis tetragonolobus) was examined for its foamability. Compared with egg white, the extract showed an extraordinary foam stability: no drainage after 3 h of standing in contrast to 65% drainage for egg white at the same protein concentration. The acid-precipitated protein from the extract was responsible for the high foamability and designated guar foaming albumin (GFA). The foaming activity of GFA was 20 times higher than that of egg white. GFA consisted of two subunits with molecular masses of 6 and 11 kDa linked to each other through disulfide bonds. The cleavage of disulfide bonds in GFA affected the foamability only slightly. GFA remarkably decreased the surface tension of water at low protein concentrations. Immunoblotting analysis demonstrated that GFA did not react to the antisera from allergic patients against plant food. These results suggest that GFA serves as an effective food additive in developing protein-stabilized foam.     

Effect of a Bowman-Birk proteinase inhibitor from Phaseolus coccineus on Hypothenemus hampei gut proteinases in vitro

The coffee berry borer, Hypothenemus hampei (Ferrari), is an important devastating coffee pest worldwide. Both trypsin and chymotrypsin enzyme activities from H. hampei larval midgut can be inactivated by proteinaceous enzyme-inhibitors. A serine proteinase inhibitor belonging to the Bowman-Birk class was purified from a wild accession of Phaseolus coccineus L. seeds. The inhibitor (PcBBI1) is a cysteine-rich protein that is heat-stable at alkaline pH. MALDI-TOF/MS analysis showed that PcBBI1 occurs in seeds as a monomer (8689 Da) or dimer (17,378 Da). Using in vitro inhibition assays, it was found that PcBBI1 has a high inhibitory activity against H. hampei trypsin-like enzymes, bovine pancreatic chymotrypsin, and trypsin. According to this, PcBBI1 could be a promising tool to make genetically modified coffee with resistance to coffee berry borer.     

Effect of the timing of first cleavage on in vitro developmental potential of nuclear-transferred bovine oocytes receiving cumulus and fibroblast cells

The aim of the present study was to examine whether cumulus and fibroblast cell nuclear-transferred oocytes, which have high and low potential to develop into normal calves, respectively, are different in terms of in their patterns of timing of first cleavage and in their relationships between timing of first cleavage and in vitro developmental potential. The timing of first cleavage was similar in both types of nuclear-transferred and in vitro fertilized oocytes. More than 86% of the oocytes cleaved within 24 h after activation or in vitro fertilization; these oocytes contributed to more than 98% of the total number of blastocysts in all three groups. The potential of oocytes that cleaved at different intervals to develop into blastocysts differed among the groups. The developmental potential of the cumulus cell nuclear-transferred oocytes and in vitro fertilized oocytes decreased with the increase in time required for cleavage. Fibroblast cell nuclear-transferred oocytes that cleaved at 20 h, an intermediate cleaving time, had higher potential to develop into blastocysts. The results of the present study suggest that the type of donor nucleus used for nuclear transfer affects the timing of first cleavage.     

A phylogeographic study of the Japanese earthworm,Metaphire sieboldi (Horst, 1883) (Oligochaeta: Megascolecidae): Inferences from mitochondrial DNA sequences

To clarify the historical phylogeography of a Japanese earthworm, nucleotide sequence variations of Metaphaire sieboldi were investigated with respect to its geographic distribution. Sequencing of mitochondrial DNA (mtDNA), including the cytochrome oxidase subunit I (COI) region and the 16S rDNA region, of 72 samples including 4 outgroup taxa, and phylogenetic analyses using neighbour-joining (NJ) and Bayesian inference (BI) methods indicated that M. sieboldi forms a monophyletic group. This monophyletic group was divided into seven subgroups; most subgroups comprised individuals from several areas, except for southern Shikoku and southern Kyushu. The phylogenetic tree demonstrated that the Shikoku and Kinki populations were paraphyletic at the basal node, and individuals from Kyushu and western Shikoku were positioned at the advanced group. Estimated phylogeographic events based on mtDNA analyses include (1) M. sieboldi originated in Shikoku and/or Kinki, (2) individuals from Chugoku and Kyushu have a common ancestor from Shikoku, and (3) individuals from western Shikoku originated from Kyushu progenitors (about 0.4–0.5 mya) after separation by rising sea levels.     

Allantoin production and its utilization in relation to nodule formation in soybeans

A remarkable accumulation and utilization of allantoin are observed in soybean plant bearing modules (Glycine max variety A62-1). To study ita physiological role, changes in activities and distribution of the enzymes concerning the purine catabolism (i.e., xanthine oxidase, uricase, allantoinase and allantoicase) were measured during development.

Uricase activity was found in the radicles in the early stage of seedling development, and no difference of the enzyme activity was detected between the radicles of the nodulating variety (A62-) and non-nodulating variety (A62-2). On maturation the activity disappeared rapidly in radicles and appeared in leaves, pods and nodules. The activity in nodules was much higher than that in the leaves and the pods throughout the culture period.

Xanthine oxidase activity was found in the radicles and nodules.

Allantoinase activity was present in all regions of both varieties, and the specific activity in the nodules Was 2-10 times that in other regions.

Allantoicase activity was detected in the leaves, but not in the nodules.

The distribution of these enzymes suggested that allantoin is formed in the nodules and utilized mainly in the leaves after translocation.

Changes in the allantoin concentration and in the activities of uricase and allantoicase were studied in non-nodulating soybean (A62-2) grown in a culture solution containing various nitrogenous compounds. The allantoin concentration in the leaves increased as the plants were cultured in the solution containing 100 ppm of nitrate-N, urea-N or allantoin-N, whereas no uricase activity in the root was detected. The specific activity of uricase decreased in the process of plant development in all cultures. Allantoicase activity increased in the roots and leaves when the plants were cultured in this solution containing 100 ppm of urea-N or allantoin-N, indicating that allantoin is utilized easily in the soybean plants.

Intracellular localization of uricase in the nodules was studied by the method of linear sucrose density gradient centrifugation. The uricase activity was associated with the bacteroids, density 1.25.

The uricase activity peak was coincident with the peak of fonnic dehydrogenase activity (bacteria type), and not with peaks of catalase activity, cytochrome oxidase activity and absorbance at 280 nm. This evidence together with the observation by electron microscopy suggested that at uricase is associated with bacteroids.     

Characteristics and classification of an unirrigated anthropogenic-alluvial soil found in the Kumamoto Plain

In Japan anthropogenic-alluvial soils excluding irrigated rice soils are lagging for behind other genetic soil types in pedological investigations. Although there are some investigations of anthropogenic-alluvial soils used for mulberry plantations, orchards, vegetable gardens, and seeding beds for trees, the main object of these investigations is not pedological. Kanno et al. (1) reported that unirrigated anthropogenic-alluvial soils used for vegetable growing in the Chikugo Plain resemble the “Alochthonous brown warp soil” defined by Kubiena (2). First of all, it is of great importance to accumulate general data for unirrigated anthropogenic-alluvial soils and to develop the classification principles for them. Classification problems will be settled in accordance with the accumulated data. This paper deals with characteristics of an unirrigated anthorpogenic-alluvial soil found in the Kumamoto Plain and with classification principles for it. These principles have almost never been described for a pedological standpoint in Japan.     

An institutional case study of Japanese Water Users Association: towards successful participatory irrigation management

This paper examines irrigation management conduct within the Japanese Water Users Association (WUA), namely the Land Improvement District (LID). LID is regarded as a successful case of participatory irrigation management (PIM), in which there are few conflicts over water between farmers so that it attains high social cost performance. However, the management system of LID still remains obscure. We throw light on this system assuming the existence of "the rule of fairness". Farmers operate the irrigation facilities in a self-serving way and have their own rule of fairness, such as upstream superiority, based on the long-term experiences of irrigation systems. We defined this rule of fairness as made up of two components: one is "fairness of outcome" and the other is "fairness of procedure". Finally, we discovered that the approach of LID staff is the essential factor to satisfying the farmers' criteria of fairness and maintaining peace; LID staff place importance on farmers' customary rules, taking care to remain neutral in arbitrating quarrels between farmers and trying to ensure organizational transparency to farmers. This can be also a good lesson for future PIM projects.