Estimation of temporal changes in the growth of green turtles <Emphasis Type="Italic">Chelonia mydas</Emphasis> in waters around the Ogasawara Islands     

Eiji Tanaka 《Fisheries Science》2009,75(3):629-639

Biological and life-cycle information is essential to any fisheries management program. We have investigated temporal changes in growth parameters in the von Bertalanffy growth curve for green turtles, Chelonia mydas, in waters around the Ogasawara Islands. The variance model of individual variability of growth used in our study was one derived from the stochastic differential equation with the white noise of constant intensity. Maximum likelihood estimates of the parameters were made using the data of 102 recovery records of tagging experiments from 1974 to 1995. The estimations were carried out for each of two models of linear and sudden changes in the parameters, and the best model was selected using Akaike's information criterion. The selected model was that all of the parameters excepting asymptotic straight carapace length were linear functions of year and that the asymptotic length was constant over the years. The estimated values of the growth coefficient in 1974 and 1995 were 0.0317 and 0.192 per year, respectively, and the estimated value of the asymptotic straight carapace length was 97.2 cm. Implications of the results and future issues to be resolved in near future are discussed.  相似文献   

Orientation control of cellulose nanofibrils in all-cellulose composites and mechanical properties of the films     

Shuji Fujisawa  Eiji Togawa  Noriko Hayashi 《Journal of Wood Science》2016,62(2):174-180

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T4-type bacteriophage communities estimated from the major capsid genes (g23) in manganese nodules in Japanese paddy fields     

Vita Ratri CAHYANI  Jun MURASE  Eiji ISHIBASHI  Susumu ASAKAWA  Makoto KIMURA 《Soil Science and Plant Nutrition》2009,55(2):264-270

The present study compared the capsid gene ( g23 ) of T4-type bacteriophages (phages) in Mn nodules with those in the plow layer soil and subsoils of two Japanese paddy fields by applying the primers MZIA1bis and MZIA6 to DNA extracts from the nodules and soils. The deduced amino acid sequences of the g23 genes in the Mn nodules were similar to those in the plow layer soil and in the subsoils. This result indicated that similar T4-type phage communities developed at these sites and that the diversity of T4-type phage communities was wide enough to cover those in the plow layer soil and in the subsoils. The majority of g23 clones formed several clusters with the clones and phages obtained from far-apart paddy fields, and the sequences of two clones were completely identical to a phage and a clone from other paddy fields at the nucleotide or amino acid level, indicating horizontal transfer of g23 genes between those paddy fields. A clone with a long nucleotide residue (686 bp) and a distribution remote from the other clones in the phylogenetic tree indicated that there were many uncharacterized, novel g23 genes in the paddy fields.  相似文献   

Potential of near infrared spectroscopy to determine the lipid content of untreated garbage compost     

Takayuki FUJIWARA  Keiichi MURAKAMI  Eiji YOSHIDA  Itaru TAKAHASHI 《Soil Science and Plant Nutrition》2009,55(2):309-314

The purpose of the present study was to evaluate the capability of near infrared spectroscopy (NIRS) as a simple method to monitor the lipid content of garbage compost, which is a potential inhibitor of plant growth. We conducted a cultivation experiment with vegetable mock pak choy ( Brassica rapa L. Parachinensis Group) using two application rates of four garbage composts that differed in lipid content. The input of lipid from the compost to the field showed a significant negative correlation with germination rate and plant height in the initial growth stage. Reflectance spectra of untreated and freeze-dried and milled compost samples were taken using a scanning monochromator. Second-derivative spectra and multiple regression analysis were used to develop calibration equations for lipid and moisture contents. The calibration was carried out with the short wavelength region ([SWR] 800–1100 nm) and the long wavelength region ([LWR] 1100–2500 nm) separately. The calibration equations with the LWR were more accurate than those with the SWR for lipid and moisture determinations. The accuracies of the calibration equations for untreated samples were comparable to those for freeze-dried and milled samples. In conclusion, we suggest that the application rate of garbage compost can be determined by measuring the lipid content of untreated samples by NIRS.  相似文献   

Identification of a peptide in enzymatic hydrolyzate of cheese that inhibits ovalbumin permeation in Caco-2 cells     

Tanabe S  Isobe N  Miyauchi E  Kobayashi S  Suzuki M  Oda M 《Journal of agricultural and food chemistry》2006,54(18):6904-6908

Because the first step in the triggering of food allergy is the permeation of the allergen through the intestine, enhancement of the intestinal barrier function is thought to be effective for preventing food allergy. In this study, a peptide that inhibits ovalbumin (OVA) permeation in an in vitro Caco-2 cell model was isolated from enzymatic hydrolyzate of cheese (EHC). Amino acid sequence analysis identified the active peptide as GPIVLNPWDQ, a sequence identical to amino acids 102-111 of alphas2-casein. The decapeptide significantly inhibited OVA permeation at a concentration of 10(-6) M. In addition, it was found that a pentapeptide half, NPWDQ, is essential for the inhibitory activity because NPWDQ but not GPIVL had nearly the same inhibitory activity as GPIVLNPWDQ. The possibility exists that EHC and/or peptides possessing the NPWDQ sequence can be practically applied to the prevention of food allergy.  相似文献   

Strategies and engineering adaptions to disseminate SRI methods in large-scale irrigation systems in Eastern Indonesia   总被引：1，自引：0，他引：1  

Shuichi Sato  Eiji Yamaji  Takeshi Kuroda 《Paddy and Water Environment》2011,9(1):79-88

The system of rice intensification (SRI) developed in Madagascar has been controversial in part because there have been no large-scale, long-term evaluations of the impact of its alternative methods. This paper summarizes experience with the dissemination of SRI practices across eight provinces in Eastern Indonesia over nine seasons from 2002 to 2006 under a major irrigation project. The Decentralized Irrigation System Improvement Project (DISIMP) was financed by the Japanese Government with project management by a Nippon Koei consultant team. SRI has been introduced in Indonesia via several organizations and in different parts of the country starting in 2000. The evaluation reported here, made by the DISIMP technical assistance team, is based on data from 12,133 on-farm comparison trials that covered a total area of 9,429 ha. Under SRI management, average paddy yield increase was 3.3 t/ha (78%). This was achieved with about 40% reduction in water use, 50% reduction in chemical fertilizer applications, and 20% lower costs of production. The farmers whom DISIMP was assisting to take up SRI were usually cultivating their paddy fields individually within irrigation systems where it was difficult to reduce water applications as recommended for SRI. Accordingly, innovations had to be made in soil and water management to create relatively aerobic soil conditions so that farmers could get the more productive rice phenotypes expected from SRI practice. This article describes the modifications made to adapt SRI concepts, pointing to the value of introducing in-field ditches, which was confirmed through paddy tract surveys. This experience and analysis showed how SRI methods could be utilized within irrigation systems where water management was not (yet) tailored to SRI production practices. Subsequently, modifications in irrigation system management are being made to be more supportive of SRI cultivation.  相似文献   

Improved porcine model for Shiga toxin‐producing Escherichia coli infection by deprivation of colostrum feeding in newborn piglets          下载免费PDF全文

Toshio Sato  Takashi Hamabata  Eiji Takita  Takeshi Matsui  Kazutoshi Sawada  Taishi Imaoka  Nobuo Nakanishi  Keizo Nakayama  Takamitsu Tsukahara 《Animal Science Journal》2017,88(5):826-831

Porcine edema disease (ED) is a toxemia caused by enteric infection with Shiga toxin 2e (Stx2e)‐producing Escherichia coli (STEC). ED occurs most frequently during the weaning period and is manifested as emaciation associated with high mortality. In our experimental infection with a specific STEC strain, we failed to cause the suppression of weight gain in piglets, which is a typical symptom of ED, in two consecutive experiments. Therefore, we examined the effects of deprivation of colostrum on the sensitivity of newborn piglets to STEC infection. Neonatal pigs were categorized into two groups: one fed artificial milk instead of colostrum in the first 24 h after birth and then returned to the care of their mother, the other breastfed by a surrogate mother until weaning. The oral challenge with 10¹¹ colony‐forming units of virulent STEC strain on days 25, 26 and 27 caused suppression of weight gain and other ED symptoms in both groups, suggesting that colostrum deprivation from piglets was effective in enhancing susceptibility to STEC. Two successive STEC infection experiments using colostrum‐deprived piglets reproduced this result, leading us to conclude that this improved ED piglet model is more sensitive to STEC infection than the previously established models.  相似文献   

Relationship between fallow period,forest vegetation and weeds in swidden agriculture in northern Laos     

Chika Kameda  Eiji Nawata 《Agroforestry Systems》2017,91(3):553-564

Weed suppression is an important reason for fallowing in swidden systems. Recently, in Laos, an increase in weeds and resulting increase in labor input has become a problem; however, causal factors influencing weed growth and weeding labor other than fallow period have yet to be fully examined. Therefore, an experimental research on swidden weeds, combining a forest survey and interviews with local farmers, was conducted in a mountain village in northern Laos where swidden agriculture is practiced as a major means of livelihood. Weed amount, weed composition and time required for weeding were found to be more influenced by fallow vegetation than fallow period. Bushy vegetation in a short fallow field was shown to lead to abundance of herbaceous weeds, resulting in higher labor input. There was a possibility that increases in some bamboo species were a cause of recent weed increases. Based on the results, we suggest that maintaining a minimum fallow period of forest fallowing, with fallow management to suppress bamboo and promote tree growth may be effective in reducing labor input in swidden agriculture.  相似文献   

The effects of irrigation method, age of seedling and spacing on crop performance, productivity and water-wise rice production in Japan   总被引：4，自引：4，他引：0  

Tejendra Chapagain  Eiji Yamaji 《Paddy and Water Environment》2010,8(1):81-90

A field experiment using system of rice intensification (SRI) techniques was conducted in Chiba, Japan during the 2008 rice-growing season (May–September) with eight treatment combinations in a split–split plot design (S–SPD) to observe the potential of SRI methods under the temperate climatic conditions in Japan. Intermittent irrigation with alternate wetting and drying intervals (AWDI) and continuous flooding throughout the cropping season were the two main-plot factors, while the effects of age of seedlings and plant spacing were evaluated as sub and sub–sub plot factors, respectively. The experiment results revealed that the proposed AWDI can save a significant amount of irrigation water (28%) without reduced grain yield (7.4 t/h compared with 7.37 t/h from normal planting with ordinary water management). Water productivity was observed to be significantly higher in all combinations of practices in the intermittent irrigation plots: 1.74 g/l with SRI management and AWDI as compared to 1.23 g/l from normal planting methods with ordinary water management. In addition, the research outcomes showed a role of AWDI in minimizing pest and disease incidence, shortening the rice crop cycle, and also improving plant stand until harvest. Synergistic effects of younger seedlings and wider spacing were seen in tillering ability, panicle length, and number of filled grains that ultimately led to higher productivity with better grain quality. However, comparatively better crop growth and yields when using the same SRI practices with ordinary water management underscore a need for further investigations in defining what constitute optimum wetting and drying intervals considering local soil properties, prevailing climate, and critical watering stages in rice crop management.  相似文献   

Phosphorus compounds and their solubility in swine manure compost     

Teppei Komiyama  Seiichi Niizuma  Eiji Fujisawa  Hiromasa Morikuni 《Soil Science and Plant Nutrition》2013,59(3):419-426

In the Japanese warm areas, as a result of intensive and repeated potato cropping, common scab, a soil-borne disease has become a serious problem. The soil moisture level has been shown to be an important factor affecting the incidence of common scab. That is, a high level of soil moisture reduces the severity of common scab. However, in this investigation, although during the spring cropping precipitation was abundant, a large number of tubers showing scab lesions were produced. The results indicate that the soil moisture level may not be an important factor affecting the incidence of potato scab in the humid region.

To identify other factors which may affect scab severity, the relation between sugar content in the peel of potato tuber and the incidence of common scab was investigated. Generally, the amount of reducing sugar in the tuber peel increased gradually with the growth of the tubers, then reached a maximum level two weeks after the start of tuber formation, and thereafter declined. The period corresponding to the highest sugar content in peels coincided with the most susceptible period for scab infection. The content of reducing sugar in the peel of susceptible cultivars was higher than that of the resistant cultivars, throughout the tuber growth, and the critical value of the content was 2.0 mg per 100 g fresh peel. These results suggest that the content of reducing sugar in tuber peel may be an important factor affecting the incidence of common scab.  相似文献