Physico-chemical characteristics of the soils developed from alluvial deposits on Chongming Island in Shanghai,China

The effects of the water extracts of rapeseed cakes undergoing decomposition under different conditions on plant growth were evaluated using Lemna paucicostata 6746 for the bioassays. Half-strength Hutner’s medium was used as the basal medium, to which aliquots of concentrated water extracts were added in the ratio of 1/1,000, and the number of reproduced fronds were counted after 7 days as an index of the growth.

Aerobic decomposition of rapeseed cake (1:1 ratio of rapeseed cake to water, w/w) showed a strong inhibitory effect on the growth of L. paucicostata 1 to 4 weeks after the start of the decomposition. In the submerged decomposition (1 : 10 ratio of rapeseed cake to water, w/w), no inhibition was detected in the first weeks, but a strong inhibition appeared after 8 weeks and increased thereafter. The water extracts of the rapeseed cake undergoing decomposition under the submerged condition contained large amounts of fatty acids (acetic, propionic, and butyric acid), which were considered to be the main phytotoxins inhibiting the growth of L. paucicostata. In the aerobic decomposition, the concentrations of both ammonium nitrogen and lower fatty acids were too low to inhibit plant growth, suggesting that other decomposed products were concerned with the inhibition.

As the bioassay with L. paucicostata showed similar results to those previously obtained by germination tests, it is considered that the use of L. paucicostata could be generalized to other crop plants.     

Distribution of acidophilic iron- and sulphur-oxidizing bacteria in a sulphur and iron sulphide mine

Abstract

The numbers of acidophilic iron- and sulphur-oxidizing chemolithotrophic bacteria, as well as certain physical and chemical environmental factors, were examined in weathered iron sulphide ores and acid mine drainage waters at the abandoned Matsuo sulphur and iron sulphide mine in Japan. In the ores, the population of iron-oxidizing bacteria was smaller than that of sulphur-oxidizing bacteria. On the other hand, an inverse relationship between iron- and sulphur-oxidizing bacteria was observed in the acid mine waters. The marked differences between the ores and acid mine waters in their numbers of iron- and sulphur-oxidizing bacteria, may reflect the availability and content of the respective energy sources: ferrous iron and elemental sulphur.     

Recent applications of metabolomics in plant breeding

Metabolites play a central role in maintaining organismal life and in defining crop phenotypes, such as nutritional value, fragrance, color, and stress resistance. Among the ‘omes’ in biology, the metabolome is the closest to the phenotype. Consequently, metabolomics has been applied to crop improvement as method for monitoring changes in chemical compositions, clarifying the mechanisms underlying cellular functions, discovering markers and diagnostics, and phenotyping for mQTL, mGWAS, and metabolite-genome predictions. In this review, 359 reports of the most recent applications of metabolomics to plant breeding-related studies were examined. In addition to the major crops, more than 160 other crops including rare medicinal plants were considered. One bottleneck associated with using metabolomics is the wide array of instruments that are used to obtain data and the ambiguity associated with metabolite identification and quantification. To further the application of metabolomics to plant breeding, the features and perspectives of the technology are discussed.     

Improving rearing performance in sea‐cage culture of Pacific bluefin tuna Thunnus orientalis juveniles (Temminck and Schlegel) using small sea cages

High levels of mortality occur in large net‐cage culture of Pacific bluefin tuna (PBF) Thunnus orientalis due to poor growth on commencement of sea‐cage culture obstructing the mass production of fingerlings. Therefore, we carried out this study to develop a countermeasure by using small sea cages (square with 13‐m sides). PBF juveniles were directly transferred to a 30‐m‐diameter cage (control) and compared them to fish transferred to small sea cages for 12 days before being merged into another 30‐m‐diameter cage. The survival rate, growth performance and potential factors increasing mortality were examined. The results of our study showed that survival rate in small sea cages was approximately 20% higher than that of the control. Poor growth also occurred in the small sea cages; however, its frequency and daily mortality rate were half those in the control. In addition, growth performance such as specific growth rate and weight gain of PBF juveniles in small sea cages significantly increased compared to the control. These results suggest that using small sea cages could be an effective countermeasure for poor growth, which may mitigate the high‐mortality conditions of current sea‐cage culture systems for PBF.     

Optimum insurance contract of flood damage index insurance for rice farmers in Myanmar

Climate change is an underlying cause of many extreme events such as enormous cyclones and erratic torrential rains. These phenomena threaten farmers in coastal regions of Myanmar. Self-insurance through means such as crop diversification is insufficient for sustainable farm management. Weather index insurance (WII) is receiving much attention because of its low management costs. An optimum WII contract for flood damage using rainfall as the index has been proposed for rice farmers in coastal regions. According to the model, an insurance payment demand function is derived by solving the expected utility maximization problem. The utility function of the contract is specified as constant relative risk aversion type. The production function is specified as Cobb–Douglas type. By substituting real average data of rice production of farmers into this function, the optimum insurance payment and premium are obtained. Changes in insurance compensation by payments according to an increase in the price of rice, rainfall, and degree of risk aversion are investigated. Results suggest that if an average farmer pays around 41.5 US dollars per year, then farm management will be optimally stabilized under the flood risk.

     

Effect of water temperature on gonadal development and emaciation of Japanese common squid <Emphasis Type="Italic">Todarodes pacificus</Emphasis> (Ommastrephidae)

ABSTRACT:   In this study, the site of spawning ground and the relationship between oceanographic conditions and gonadal development and emaciation of the Japanese common squid Todarodes pacificus were examined based on data from research cruises. The research cruises were conducted in the south-western part of the Sea of Japan and the East China Sea in the winter of 1999. Sea surface temperature (SST) ranged 12.7–23.2°C in the survey area. Mature females concentrated on the continental shelf of the East China Sea, suggesting a major spawning ground was formed in this area. Gonadal development of the collected squid was examined using ovary somatic index (OSI) and oviduct somatic index (ODSI) in females, and emaciation was examined using mantle muscle somatic index (MI) and hepatosomatic index (HSI). Mean OSI and ODSI increased with SST at the stations where SST was greater than 15°C, particularly where SST ranged between 15 and 18°C. In contrast, mean MI and HSI decreased with increase in SST at the stations where SST was above 15°C. These results indicate that female gonads develop rapidly at SST above 15°C, and at the same time adult squids tend to be emaciated at this temperature condition.     

Laboratory observations on the vertical swimming behavior of Japanese common squid Todarodes pacificus paralarvae as they ascend into warm surface waters

This study examined the effect of warm temperature on the survival of paralarvae of Japanese common squid Todarodes pacificus and on their swimming behavior as they ascended to the surface. Observations were conducted on paralarvae in Petri dishes and in 85-cm-tall, cylindrical tanks that had a warmer upper layer and cooler lower layer separated by a small thermocline. Paralarvae were obtained through artificial fertilization and reared in Petri dishes at six experimental temperatures between 20.9 and 30.4 °C. Paralarvae reared at lower temperatures survived longer than those reared at warmer temperatures, and survival decreased at temperatures above 24 °C. When the mean temperatures in the upper layer of the tanks were 24.4–26.0 °C, the paralarvae ascended through the thermocline to the surface, but when the mean temperatures in the upper layer were 29.7–29.8 °C, paralarvae stopped ascending at the thermocline. These results show that paralarvae have a temperature preference but ascend to the surface in the unfavorable temperature range. The results suggest that increasing surface temperatures at spawning grounds will negatively affect both the survival and behavior of T. pacificus paralarvae.     

Towards integrated research in fisheries science

In this paper we present a call for a re-directing fisheries science towards an integrated scientific activity which includes the trajectory of fish from eggs and their life underwater to consumption on the table. We propose that integrated research in fisheries science be defined as “interdisciplinary research for society and human well-being which deals with the sustainability of dynamic fisheries systems, taking various knowledge, values, and needs into account.” As an integrative discipline, fisheries science offers many advantages to overcoming the limitations of the traditional sciences. The ability to conduct traditional research activities based on each academic discipline is a prerequisite to participating in integrated research. However, “additional processes” are needed, such as the introduction of new integrated thinking, joint determination of the research framework, mutual learning by participating researchers, interaction with stakeholders, among others. Integrated research in fisheries science would allow overall influences to be analyzed, including exogenous factors such as environmental changes and other marine industries. Walleye pollock Theragra chalcogramma provides a good model species for analyzing future scenarios of the structure of the industry as well as potential strategies for addressing and considering the effects of other highly fluctuating resources. One of the most challenging topics is identifying possible paths from a depleted stock to its future recovery. Scientific analyses on “How fast?” “Who should bear the costs?” “When it will occur”, etc., should be conducted by close interactions with stakeholders.     

Expression of feline interferon-alpha subtypes in Esherichia coli, and their antiviral activity and animal species specificity

Two kinds of FeIFN-alpha consisting of 166 amino acids (aa) and 171 aa were expressed in Escherichia coli, and the purified proteins were tested for antiviral activity on homologous and heterologous animal cells. Crude FeIFN induced in feline cells revealed antiviral activity on both homologous and heterologous animal cells. In contrast, both types of recombinant FeIFN-alpha revealed antiviral activity only on the feline cells. All of the FeIFN-alpha subtypes showed high activity to vesicular stomatitis virus, and the three species of feline viruses belonging to different families.