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Search Results: 1 - 10 of 149745 matches for " H. Ikeura "
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Attractant and Oviposition Stimulant of Crataeva religiosa Forst. to Pieris rapae
H. Ikeura,F. Kobayashi,Y. Hayata
Asian Journal of Plant Sciences , 2010,
Abstract: We were aimed to confirm the oviposition preference of P. rapae against C. religiosa (Capparidaceae plant) and cabbage (Brassicaceae plant) and then analyzed the AITC and sinigrin contents and myrosinase activity in these plants to clarify the attractant and oviposition stimulant properties of C. religiosa and cabbage to P. rapae. We analyzed the attractant and oviposition stimulant of a Brassicaceae plant, Brassica oleracea var. capitata L. (cabbage) and a Capparidaceae plant, Crataeva religiosa to Pieri srapae crucivora Boisduval by the oviposition preference test. The oviposition preference of P. rapae was the highest in cabbage, followed by C. religiosa, but the lettuce (control plant) was rarely selected. Allylisothiocyanate (AITC), which is assumed to be one of the attractant and sinigrin as oviposition stimulants were detected in cabbage using GC-MS. Their compounds were not detected in C. religiosa, but the higher content of methylisothiocyanate (MITC) that is analogous to AITC was found. Myrosinase activity was analyzed by HPLC and detected in cabbage and C. religiosa, but not in lettuce. Glucosinolate of sinigrin analogous in C. religiosa fractionated by HPLC was decreased by myrosinase treatment and then produced MITC. We identified that this compound was glucocapparin as a precursor of MITC by LC-MS. These results revealed that C. religiosa have a glucosinolate-myrosinase metabolic system and pathway.
Deodorizing Ability of Houttuynia cordata Thunb. (Dokudami) for Masking Garlic Odor
Hiromi Ikeura
Journal of Agricultural Science , 2012, DOI: 10.5539/jas.v4n4p245
Abstract: The deodorizing activity of dokudami (HouttuyniacordataThunb.) for masking the odor of fresh garlic was investigated, and the volatility of the deodorizing compounds was examined. Two grams of garlic was placed in a beaker and heated for 5 min at 40 °C. Next, aliquots of 0.01 and 0.05 g of powdered samples of seven plants (dokudami, thyme, rosemary, coriander, dandelion, spiny sow thistle and green tea) were mixed with 1 ml of volatile or non-volatile dokudami extract and added to the garlic sample. The garlic odor intensity was subsequently evaluated by sniffing by 10 trained individuals. The deodorizing activity test was carried out at 0, 3 and 6 h after adding the dokudami extract. The deodorizing effect of dokudami on masking garlic odor was the highest of any plant and became higher with increased dose. In addition, the deodorizing activity of dokudami increased with time and persisted. Moreover, whether the deodorizing compounds of dokudami were volatile or non-volatile was investigated. The deodorizing activity of a volatile solution of dokudami against garlic was extremely higher than that of dokudami dry powder. Our findings revealed that the deodorizing compound of dokudami is volatile.
Required amounts of medium and fertilizer for potted culture of zucchini  [PDF]
Hiromi Ikeura, Takahiko Tokuda, Yasuyoshi Hayata
Agricultural Sciences (AS) , 2012, DOI: 10.4236/as.2012.36099
Abstract: In Japan, zucchini culture has yet to get underway, and the current costs of zucchini can be attributed to damage from soil-borne disease and the unstable yields due to seasonal change of female flowers. Eradication of these problems will lead to stable supply and a consequent price reduction of zucchini fruits. We previously clarified the efficacy of potted culture as a new culture method for zucchini, but potted culture can be burdensome as the weak water and nutrient retention capacity of the medium warrants its regular replacement. To solve this problem, in this study, we investigated the blend ratio for mixing rice husk charcoal with peat and the amount of fertilizer required for potted culture of zucchini. Results revealed no significant differences in the length of the largest leaf, total number of flowers, number of female flowers, and the ratio of female flowers to total flowers with different blend ratios of rice husk charcoal to peat. However, the number of harvested fruits increased with higher ratios of rice husk charcoal to peat and was highest at 80:20. The length of the largest leaf increased with increased amounts of fertilizer, with the best response was at 200 g. No significant differences were noted between the ratio of female flowers to total flowers in any treatments. In addition, the number of harvested fruits was highest with 160 g and 200 g of fertilizer. Taken together, the optimal blend ratio of rice husk charcoal to peat is 80:20, and the optimal amount of fertilizer with this ratio is 160 g.
Improving Interactions between a Power-Assist Robot System and Its Human User in Horizontal Transfer of Objects Using a Novel Adaptive Control Method
S. M. Mizanoor Rahman,Ryojun Ikeura
Advances in Human-Computer Interaction , 2012, DOI: 10.1155/2012/745216
Repellent Effect of Herb Extracts on the Population of Wingless Green Peach Aphid, Myzus persicae Sulzer (Hemiptera: Aphididae)
Hiromi Ikeura,Fumiyuki Kobayashi,Yasuyoshi Hayata
Journal of Agricultural Science , 2012, DOI: 10.5539/jas.v4n5p139
Abstract: Investigation of the repellent and insecticidal effects of 8 kinds of herb extracts (chives, dokudami, eucalyptus, lavender, peppermint, cherry sage, sweet pepper and tansy) against wingless green peach aphids were conducted in laboratory and field test. In laboratory repellent tests, 20 aphids were placed between a radish leaf and filter paper for 16 h and aphids on radish leaf were calculated. In laboratory insecticide tests, 20 aphids were placed on a radish leaf treated with herb extract, and live aphids were counted after 16 h. In field tests, the number of aphids that propagated on radish leaves treated with each herb extract was assessed every 3 days. In the laboratory, dokudami, tansy and sweet pepper extracts repelled aphids, while chives, sweet pepper and tansy extracts killed them. In particular, sweet pepper and tansy extracts proved to be a potent insecticide against aphids. In the field test, the results found that extracts from dokudami, cherry sage and lavender had repellent effect on aphids. In particular, dokudami extract was a highly effective repellent against aphids. These findings suggest that dokudami extract can be used to control wingless green peach aphids in the field.
Repellent Effects of Volatile Extracts from Herb Plants against Larvae of Pieris rapae crucivora Boisduval
Hiromi Ikeura,Fumiyuki Kobayashi,Yasuyoshi Hayata
Journal of Agricultural Science , 2012, DOI: 10.5539/jas.v4n5p145
Abstract: Environmental pollution and intensive use of toxic chemicals, as well as resistance to pesticides, has forced scientists to find new ways of controlling pests. Numerous substances that repel insects and inhibit eating and egg-laying have been discovered in a variety of plants. The cabbage white butterfly, Pieris rapae crucivora Boisduval, is a serious pest to Brassicaca species such as cabbage, cauliflower and broccoli, and its larvae damage the host plant leaves when feeding. In this study, to develop a botanical insecticide against P. rapae larvae, we assessed the effect of 7 kinds of herb (rosemary, spearmint, eucalyptus, sage, chili pepper, chives and tansy) extracts as feeding repellents against P. rapae larvae. Feeding repellent tests were conducted by placing two cabbage leaf disks on filter paper treated with herb extract or diethyl ether in a box; then a larva was placed between the disks and its preference was observed. The repellent rate of rosemary, spearmint, eucalyptus, sage, chili pepper, chives and tansy was 75%, 72%, 64%, 59%, 40%, 40% and 36%, respectively. These results clarified that of the tested herbs, rosemary and spearmint volatile extracts have a notable feeding repellent effect against P. rapae larvae.
Improving Interactions between a Power-Assist Robot System and Its Human User in Horizontal Transfer of Objects Using a Novel Adaptive Control Method
S. M. Mizanoor Rahman,Ryojun Ikeura
Advances in Human-Computer Interaction , 2012, DOI: 10.1155/2012/745216
Abstract: Power assist systems are usually used for rehabilitation, healthcare, and so forth.This paper puts emphasis on the use of power assist systems for object transfer and thus brings a novelty in the power-assist applications. However, the interactions between the systems and the human users are usually not satisfactory because human features are not included in the control design. In this paper, we present the development of a 1-DOF power assist system for horizontal transfer of objects. We included human features such as weight perception in the system dynamics and control. We then simulated the system using MATLAB/Simulink for transferring objects with it and (i) determined the optimum maneuverability conditions for object transfer, (ii) determined psychophysical relationships between actual and perceived weights, and (iii) analyzed load forces and motion features. We then used the findings to design a novel adaptive control scheme to improve the interactions between the user and the system. We implemented the novel control (simulated the system again using the novel control), the subjects evaluated the system, and the results showed that the novel control reduced the excessive load forces and accelerations and thus improved the human-system interactions in terms of maneuverability, safety, and so forth. Finally, we proposed to use the findings to develop power assist systems for manipulating heavy objects in industries that may improve interactions between the systems and the users. 1. Introduction Power assist system is a human-robot system that augments human’s abilities and skills in performing tasks [1]. Breakthrough in power assist systems was conceived in early 1960s with “Man-amplifier” and “Hardiman”, but the research on this promising field is not so satisfactory yet [1]. Currently, power assist systems are developed mainly for the sick, disabled and old people as rehabilitation and healthcare assistance [2, 3]. A few power assist devices have also been developed for other applications for example, lifting baby carriage [4], supporting agricultural works [5], hydraulic power-assist for automobiles [6], skill-assist in manufacturing [7], power-assisted slide doors for automobiles [8], power-assisted control for bicycle [9], power assistance for sports and horse training [10, 11], and so forth. We think that handling heavy objects, which is common and necessary in industries, may be another potential field of application of the power assist systems [12, 13]. It is very necessary to move heavy objects in industries such as manufacturing and
Multi-Input Multi-Output Integrated Ionic Polymer-Metal Composite for Energy Controls
Gou Nishida,Motonobu Sugiura,Masaki Yamakita,Bernhard Maschke,Ryojun Ikeura
Micromachines , 2012, DOI: 10.3390/mi3010126
Abstract: This paper presents an integrated sensor/actuator device with multi-input and multi-output designed on the basis of a standard control representation called a distributed port-Hamiltonian system. The device is made from soft material called an ionic polymer-metal composite (IPMC). The IPMC consists of a base film of a polyelectrolyte gel and a double layer of plated metal electrodes. The electrodes of the experimental IPMC are sectioned, and it is implemented as a control system with four pairs of inputs/outputs. We stabilize the system, and detect changes in dynamics by using the control representation.
Application of Selected Plant Extracts to Inhibit Growth of Penicillium expansum on Apple Fruits
Hiromi Ikeura,Natthamon Somsak,Fumiyuki Kobayashi,Sirichai Kanlayanarat
Plant Pathology Journal , 2011,
Abstract: Penicillium expansum is an important postharvest pathogen that not only causes decay on apple and pear fruit but also produces the carcinogenic mycotoxin patulin in spoiled fruit and processed fruit. Although synthetic fungicides are effective to protect against fruit decay, their potential effects on human health and the environment are a concern. Plant extracts are one of several non-chemical control alternatives that inspiring great interest due to their availability, non-toxicity and friendliness to the environment. In this study, screening of antifungal activity against P. expansum from sixteen plants (garlic, clove, dokudami, kumasasa, dandelion, kusagi, yomogi, ginkgo, marigold, lavender, thyme, hot pepper, ginger and lemon basil) by means of solvent extraction with either dichloromethane or diethyl ether was conducted. By the solution contact method and the vapor contact method, plant extraction of 16 plants was treated on PDA and the diameter of a clear inhibition zone was recorded daily for 5 d. Next, 100 L of conidia suspension was added to each wound on apple fruits. Lesion diameter of the treated fruits was observed daily for 6 d. The antifungal activity against P. expansum of garlic, thyme, lavender, ginkgo and dandelion which directly contacted the fungal spore, was distinguishingly affective with a clear inhibition zone diameter higher than 12 mm over 5 days of incubation. Apple fruits were treated with garlic extracts by the solution contact method. Growth inhibition activity of P. expansum in an amount of 50 L was higher than that in 20 L which was equally effective control. Apples exposed to vapor of garlic extract at 1, 2 and 3 ml L-1 for 24, 48 and 72 h show different antifungal effects on P. expansum. Vapor contact of Allium sativum at a concentration of 1 ml L-1 with 72 h of exposure time demonstrated the most optimal performance in terms of fruit appearance. In these results, dichloromethane is an appropriate solvent for use in extracting active compounds from plants presenting antifungal activity against P. expansum. Crude extract of garlic was the most effective, both in the form of solution and vapor contact, for inhibiting mycelium growth of P. expansum. In addition, garlic extract is applicable at relatively low concentration to reduce blue mold rot on apple fruits.
Application of Tomato (Solanum lycopersicum) Leaf Volatiles as Antifungal Agents against Plant Pathogenic Fungi
Fumiyuki Kobayashi,Kenji Ishida,Hiromi Ikeura,Sachiko Odake
Journal of Agricultural Science , 2012, DOI: 10.5539/jas.v4n8p231
Abstract: The antifungal activity of tomato (Solanum lycopersicum) leaf volatiles (TLV), which are industrial residues, was investigated against three types of plant pathogenic fungi of Botryotinis fuckeliana, Glomerella cingulata and Fusarium oxysporum f. sp. melonis. The growth of B. fuckeliana and G. cingulata was completely inhibited by TLV extract volumes corresponding to 12 and 17 g of tomato leaves, respectively. The inhibition rate of a TLV extract volume corresponding to 17 g of tomato leaves against F. oxysporum f. sp. melonis was approximately 55%. The antifungal activity of TLV was thus shown to vary according to the type of plant pathogenic fungi. These results suggest the presence of a defense response against plant pathogenic fungi in tomato plants and that TLV are efficacious as a biological control agent.
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