High incidence of rickettsiosis correlated to prevalence of Rickettsia japonica among Haemaphysalis longicornis tick

Endemic spotted fever group rickettsiosis was reported in Shimane Prefecture, Japan. From an analysis of 14 clinical cases found in the endemic area, the infectious agent of spotted fever group rickettsiosis was identified as Rickettsia japonica. In this study, we also found that Rickettsia japonica was highly infected with the vector tick, Haemaphysalis longicornis, in the endemic area. These findings suggest that the high incidence of rickettsiosis in Shimane Prefecture can be explained by the high prevalence of Rickettsia japonica among Haemaphysalis longicornis ticks.     

On the components of soil humic acids (part 8) the oxidative decomposition by alkaline potassium permanganate and nitric acid

As for the reactions by oxidizing agents of humic acids and for the products obtained by the said reactions, a number of investigations (1) have been made with regard to the study of the chemical structure of humic acids and with the use of the products of decomposition. The authors (2) have observed that A-or B-types of soil humic acids could be separated into three or four fundamental composing fractions by using Al²O³ column.     

On the components of soil humic acids VII

The writers already made it clear that by active alumina the humic acids of A- and B-types contained in various soils could be separated into 3 or 4 components (1). And moreover, absorption spectra (2), nitrogen constituents (3) and colloidal nature (4) of them were studied for the purpose of examining their qualities.     

The seasonal changes of the constituents of young apple trees (Part 1) total sugars and starch

Introduction

Considering the cultivation of perennials like fruit crops from the standpoint of plant nutrition as well as cultural practices, there is a great difference from annual crops; the former is expected to increase the yield of fruit on the one hand, and to maintain the tree vigour on the other. It may be said that the cultural practices of fruit crops are all directed to a single aim, that is keeping harmony between these contrary requirements. Therefore, to understand the seasonal changes of the constituents of fruit trees in accordance with the seasonal growth cycle is the fundamental of fruit culture.     

On the components of soil humic acids (Part iv) on the absorption spectra of the components of B-type humic acid

Introduction

Concerning the A-type humic acid found in different kinds of soil the writers fractionated each of its components and measured its lightabsorbing power and compared the characteristics of those components.     

Nodulation of Rj-soybean varieties with Rhizobium fredii USDA 193 under limited supply of nutrients

The compatibility between rhizobia and host plants for nodulation was determined based on the genetic and physiological properties of both symbionts. It has been observed that soybean varieties carrying the Rj-gene were not nodulated effectively by certain strains or groups of rhizobia. Soybeans carrying the Rj ₂-gene, Rj ₂-varieties, were found to nodule ineffectively by the rhizobial strains belonging to the 3-24-44 and 122 serogroups (Caldwell 1966). In the same way, Rj ₃- and Rj ₄-varieties were found to nodule ineffectively by strains USDA 33 (Vest 1970) and USDA 61 (Vest and Caldwell 1972), respectively.     

Effects of symbiosis with Rhizobium fredii on transport of fixed nitrogen in the xylem of soybean plants

An experiment was conducted to identify the main nitrogenous compound transported in the xylem sap of soybean plants nodulated with Rhizobium fredii. Soybean (Glycine max L. Merr.) cultivars, wild type Bragg (nod⁺, fix⁺) and its nitrate tolerant, hypernodulating mutant ntsll16 (nod⁺⁺, fix⁺) were used for this experiment. These soybean plants were inoculated with a slowgrowing rhizobium, Bradyrhizobium japonicum USDAllO or fast-growing rhizobia consisting of a mixture of R. fredii USDA191, USDA193, and USDA-194 and grown in a phytotron under natural light and controlled temperature conditions. Xylem sap was collected from Bragg and ntsll16 plants at the flowering and pod elongation stages. Acetylene reduction activity per plant or per nodule weight was not different between soybean lines and inoculums. The composition of the nitrogenous compounds in the xylem sap was compared between the symbionts, with B. japonicum and R. fredii. At the flowering stage, ureide-N and amide-N accounted for 53 to 70% and 20 to 27% respectively of the total N in the sap collected from the plants inoculated either with B. japonicum or R. fredii. At the pod elongation stage, ureide-N and amide-N accounted for 74 to 85%, and 7 to 19% of total sap N. With the growth of the soybean plants, the ratio of ureide-N in the xylem sap increased. These results suggest that in the case of wild soybean and the hypernodulating mutant line nodulated by R. fredii, ureide is transported as the main nitrogenous compound of fixed nitrogen in the xylem sap in the same way as in plants nodulated with B. japonicum.     

Quality evaluation of frozen surimi by using pH stat for ATPase assay

To evaluate the quality of frozen surimi, the ATPase assay system was applied to pH stat. Surimi homogenate was prepared without washing procedures as a material for the measurement. Among the possible compounds frozen surimi contains, Mg ion slightly inhibited Ca-ATPase activity, while sugars or polyphosphate did not. Thus, the surimi homogenate was directly used for ATPase assay. The quality of surimi samples with various commercial grades were analyzed by measuring Ca-ATPase activity and protein content to obtain ATPase total activity. SA grade surimi showed high total activity, and was clearly distinguished from the second grade ones by the total Ca-ATPase activity. The specific Ca-ATPase activity contributed to the total activity more than the protein content. These results demonstrated that employment of surimi homogenate and the pH stat method made the total activity measurement of surimi easy and rapid.     

Corneal Mineralization in Wistar Hannover Rats

We have recently started using Wistar Hannover rats in Japan and are now collecting background data. We have been frequently observing corneal mineralization in Wistar Hannover rats of both the RccHan^TM:WIST and Crl:WI (Han) strains. In this study, details of corneal mineralization in Wistar Hannover rats were histopathologically and ultrastructurally investigated. According to the results, Wistar Hannover rats had a much higher incidence of corneal mineralization compared with Sprague-Dawley rats. The incidence of corneal mineralization was higher in males than females. According to the histological examination, mineral deposits were positive for calcium by von Kossa’s method. Furthermore, in response to mineralization, keratocytes probably become active to play an important role against the mineralized substance.     

Estimation of evaporation from arid-irrigated region using MODIS satellite imagery

For sustainable development of irrigated agriculture in arid regions, improvement of water use efficiency is essentially required to maintain current production levels and meet food and fiber for population growth in future. To achieve high water use efficiency, a key consideration is to reduce unnecessary soil water loss due to evaporation. In this article, regional daily evaporation over Hetao Irrigation District in a typical arid region during the irrigation period of 2009 was determined by a developed maximum surface temperature model combining Moderate Resolution Imaging Spectroradiometer (MODIS) satellite imagery. The results showed that maximum land surface temperature (LST) from MODIS satellite imagery was relatively higher in the western and middle parts than that of the eastern part of the district. At the same time, the mean minimum LST was shown somewhat higher in the eastern part. Mean daily evaporation was relatively higher in the eastern part, which showed water consuming is higher in the eastern part of the district. During the irrigation period of 2009, the total income water (irrigation water and rainfall) amount is 590.3 mm, and the outcome water (drainage discharge and evaporation) amount is 497.5 mm. The surplus of 92.8 mm in the irrigated season is considered to be consumed in winter season. Throughout the irrigated season, income and outcome almost equals each other. The daily evaporation distribution map could specify particular water consuming areas over the district where high daily evaporation may be occurred.