IDEA Consultants Inc.

Yokohama-shi, Japan

IDEA Consultants Inc.

Yokohama-shi, Japan
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Ida H.,Nara Women's University | Wada K.,Nara Women's University | Wada K.,IDEA Consultants Inc.
Journal of Crustacean Biology | Year: 2017

Sexual dimorphism is common in species where one sex fights for access to the other sex, or one sex displays to attract the other sex for mating. We show that in the dotillid crab Scopimera globosa (De Haan, 1835) there is strong sexual dimorphism with males having relatively larger chelae (claws) than females. We also found that males had relatively longer walking legs (pereiopods) than females, a pattern previously shown in a few brachyuran crabs. This species exhibits five distinct aggressive behaviors and males predominantly engage in aggressive interactions. Unlike other brachyuran crabs, males do not grasp each other with their chelae during fights and chela size was not a determinant of winning such interactions. The most escalated fight, the wrestle, involves the raising of the walking legs, and leg length was a strong predictor of fighting success. We suggest that the sexual dimorphism in leg length has evolved in response to the use of the legs in determining fighting success. © 2017 The Author 2017.

Sato K.,University of Tokyo | Tateno S.,University of Tokyo | Tateno S.,Japan Agency for Marine - Earth Science and Technology | Watanabe S.,IDEA Consultants Inc. | Kawatani Y.,IDEA Consultants Inc.
Journal of the Atmospheric Sciences | Year: 2012

Gravity wave characteristics in the middle- to high-latitude Southern Hemisphere are analyzed using simulation data over 3 yr from a high-resolution middle-atmosphere general circulation model without using any gravity wave parameterizations. Gravity waves have large amplitudes in winter and are mainly distributed in the region surrounding the polar vortex in the middle and upper stratosphere, while the gravity wave energy is generally weak in summer. The wave energy distribution in winter is not zonally uniform, but it is large leeward of the southern Andes and Antarctic Peninsula. Linear theory in the three-dimensional framework indicates that orographic gravity waves are advected leeward significantly by the mean wind component perpendicular to the wavenumber vector. Results of ray-tracing and cross-correlation analyses are consistent with this theoretical expectation. The leeward energy propagation extends to several thousand kilometers, which explains part of the gravity wave distribution around the polar vortex in winter. This result indicates that orographic gravity waves can affect the mean winds at horizontal locations that are far distant from the source mountains. Another interesting feature is a significant downward energy flux in winter, which is observed in the lower stratosphere to the south of the southern Andes. The frequency of the downward energy flux is positively correlated with the gravity wave energy over the southern Andes. Partial reflection from a rapid increase in static stability around 10 hPa and/or gravity wave generation through nonlinear processes are possible mechanisms to explain the downward energy flux. © 2012 American Meteorological Society.

Yoon J.-H.,Kyushu University | Kawano S.,IDEA Consultants Inc. | Igawa S.,Japan NUS Co.
Marine Pollution Bulletin | Year: 2010

Characteristics of drift and beaching of floating marine litter in the Japan Sea are examined numerically using the reanalysis data of the Japan Sea Forecasting System of Kyushu University. The residence time of model marine litter deployed uniformly over the surface of the Japan Sea strongly depends on the buoyancy ratio. However, almost all litter beaches or flows out through straits within 3 years. Experiments with inputs of litter imposed at large cities and the Tsushima Straits as well as river basins of the Japan Sea exhibit a good agreement with beach surveys with regard to country ratios of beached litter along the Japanese coast in cases of lighters. In a case of lighter, almost all lighters originating from Japan beach along the Japanese coast, while almost all lighters originating from a country surrounding the Japan Sea except Japan beach along the coast of that country and the Japanese coast. © 2009 Elsevier Ltd. All rights reserved.

Yamada T.,Yamada Science and Art Corporation | Koike K.,IDEA Consultants Inc.
Journal of Wind Engineering and Industrial Aerodynamics | Year: 2011

Considerable interest exists in joining the capabilities of mesoscale meteorological models (MMM) with those of computational wind engineering (CWE) models to produce realistic simulations, which address emerging issues in wind engineering and environmental applications. The model equations are similar for MMM and CWE, but there are significant differences in the objectives and approaches. Complete synthesis of these models is still premature and computational burdens are enormous. Appropriate procedures for joining these models have not been established yet and measurement data required for verification is limited.For convenience in presentations and discussions, coupling methods are divided into four groups: (1) coupling MMM and CWE models for up-scaling or downscaling, (2) up-scaling a CWE model to include the mesoscale meteorological influences, (3) downscaling an MMM to include the CWE capabilities, and (4) a combination of the above three approaches. Mochida et al. (this issue) focuses on up-scaling CWE from an engineering point of view and the present paper focuses on downscaling MMM from a meteorological point of view. Topics addressed here are (1) to understand the differences in the purposes and approaches of MMM and CWE models and (2) to identify issues and explore ways of coupling MMM and CWE modeling capabilities. © 2011 Elsevier Ltd.

Miyake Y.,Fukuoka University | Tanaka K.,Fukuoka University | Masuzaki Y.,IDEA Consultants Inc. | Sato N.,IDEA Consultants Inc. | And 3 more authors.
Chemosphere | Year: 2011

Persistent organic pollutants have been shown to have immunomodulating effects in humans. However, epidemiological evidence regarding the relationships between organochlorine compound exposure and allergic disorders coming from studies of children has been limited and inconsistent. The current cross-sectional study examined the associations between the concentrations of β-hexachlorocyclohexane (HCH), hexachlorobenzene (HCB), p,p'-dichlorodiphenyldichloroethylene (DDE), and trans-nonachlordane in breast milk and the prevalence of allergic disorders in 124 adult Japanese women. The definition of wheeze and asthma was based on criteria from the European Community Respiratory Health Survey whereas that of eczema and rhinoconjunctivitis was based on criteria from the International Study of Asthma and Allergies in Childhood. Adjustment was made for age, smoking, family history of allergic disorders, and education. The prevalence values of wheeze, asthma, eczema, and rhinoconjunctivitis in the past 12months were 9.7%, 4.8%, 13.7%, and 29.8%, respectively. The median concentrations of β-HCH, HCB, p,p'-DDE, and trans-nonachlordane in breast milk were 28.3, 7.0, 71.6, and 23.9ngg -1 lipid, respectively (range, 4.5-253, 2.1-14.5, 7.5-362, and 1.8-130ngg -1 lipid, respectively). When the exposures were treated as continuous variables, no significant associations were found between concentrations of HCB, β-HCH, p,p'-DDE, or trans-nonachlordane and the prevalence of wheeze, asthma, eczema, or rhinoconjunctivitis. Our results suggest that concentrations of β-HCH, HCB, p,p'-DDE, and trans-nonachlordane in breast milk are not evidently associated with the prevalence of wheeze, asthma, eczema, or rhinoconjunctivitis in young female Japanese adults. © 2011 Elsevier Ltd.

Marionina biwaensis sp. nov. is described from Lake Biwa. This new species differs from all other Marionina species: lacking lateral chaetae completely and ventral chaetae in II, segment number 38-43, origin of dorsal blood vessel XV or XVI, spermathecal ampullae with irregular protuberances and chaetal distribution 1 per postclitellar bundles. In addition, the descriptions of M. coatesae, M. nevisensis, and M. riparia are augmented and recorded here for the first time in Japan. © TÜBİTAK.

Okamura S.,IDEA Consultants Inc. | Okabe K.,Chiyoda Corporation | Fukuoka S.,Chuo University
IAHS-AISH Publication | Year: 2013

For river management, it is important to estimate the sediment discharge rate and the degree of bed variations during floods. Many of the previous sediment transport formulae have been proposed based on results by experimental channels. Therefore, they cannot estimate well the sediment discharge rate in rivers because of the complicated channel shapes and bed forms. It is necessary to calculate the sediment discharge rate appropriately to improve the accuracy of bed variation analysis. Fukuoka (2010) thought that stable cross-sectional scales of alluvial rivers (such as width and depth) are determined by physical quantities which indicate characteristics of basins (such as discharge, river bed slope and river bed material). He then derived formulae between dimensionless quantities of width, depth and discharge using field observed data by dimensional analysis. Based on the above analysis, he also derived the bed load formula considering the effect of river width and cross-sectional form using field observed data. In this study, we develop a bed variation analysis with the Fukuoka's bed load formula to calculate the 1981 flood of the Ishikari River that caused large bed scouring at the river mouth. We compare calculated results between the bed load formula of Fukuoka (2010) and the previous formulae of Ashida & Michiue (1972) and Sato et al. (1958) for the amount of bed load discharge rates during the flood and the bed forms after the flood. As a result, the cross-sectional bed forms at meandering channel are well reproduced when we use the bed load formulae of Fukuoka (2010) and Sato et al. (1958). This indicates that these bed load formulae can calculate the amount of bed load discharge rate appropriately in the case of the Ishikari River mouth. © 2013 IAHS Press.

Yamanishi Y.,Nara Women's University | Yamanishi Y.,IDEA Consultants Inc. | Yoshida K.,Japan National Agricultural Research Center | Fujimori N.,Toyohashi University of Technology | Yusa Y.,Nara Women's University
Biological Invasions | Year: 2012

Species richness in local communities has been considered an important factor determining the success of invasion by exotic species (the biotic resistance hypothesis). However, the detailed mechanisms, especially the role of predator communities, are not well understood. We studied biotic resistance to an invasive freshwater snail, Pomacea canaliculata, at 31 sites in an urban river basin (the Yamatogawa) in western Japan. First, we studied the relationship between the richness of local animal species and the abundance of P. canaliculata, demonstrating a negative relationship, which suggests that the intensity of biotic resistance regulates local snail populations. This pattern was due to the richness of native predator communities rather than that of introduced species or non-predators (mainly competitors of the apple snail). Local snail abundance was also affected by immigration of snails from nearby rice fields (i. e. propagule pressure), where few predators occur. Second, we assessed short-term predation pressure on the snail by means of a tethering experiment. Predation pressure was positively correlated with the number of individual predators and negatively correlated with snail abundance. The introduced crayfish Procambarus clarkii was responsible for the variance in predation pressure. These results indicate that the predator community, composed of both native and introduced species, is responsible for resistance to a novel invader even in a polluted urban river. © 2011 Springer Science+Business Media B.V.

Kakinuma T.,Kagoshima University | Tsujimoto G.,Kobe City College of Technology | Yasuda T.,Kyoto University | Tamada T.,IDEA Consultants Inc.
Coastal Engineering Journal | Year: 2012

The field survey results obtained by the team of authors in the north of Miyagi Prefecture between April 1 and 6, 2011 are summarized referring to a part of the survey results by other teams of the 2011 Tohoku Earthquake Tsunami Joint Survey Group. The inundation height above sea level was measured using a laser range finder with a reflection prism. The inundation height was generally larger at bay heads, as well as promontory tips, except several points, which were sheltered by a peninsula or had a tapering area. The tsunamis reached inland far away from the sea along valleys and rivers. Not only steel frame buildings but also many reinforced concrete buildings were collapsed in Onagawa Town. According to the numerical results, the first of tsunamis from the west coast and the second of tsunamis from the east coast should come together in Utatsusaki Peninsula, which is consistent with the interviews to survivors. © 2012 World Scientific Publishing Company and Japan Society of Civil Engineers.

Three species of semi-aquatic freshwater Enchytraeidae of the genera Mesenchytraeus Eisen, 1878, Chamaedrilus Friend, 1913 and Globulidrilus Christensen & Dózsa-Farkas, 2012 are described from stream, wet soil or snow habitats in the Ozegahara Mire, an extensive high moor in heavy snowfall area in central Japan. Among Mesenchytraeus speies, Mes-enchytraeus nivalis sp. nov. is distinguished by not having enlarged chaetae and spermathecal diverticula, vas deferens with atrial glands 3 or 4 in number and club-shaped, spermathecal ental duct short, with sperm bundles in the sperm sack. Chamaedrilus ozensis sp. nov. closely resembles C. floridae, but the length of the sperm funnel and character of the coelo-mocytes are different. Globulidrilus helgei Christensen & Dózsa-Farkas, 2012 is recorded for the first time from Japan. Copyright © 2015 Magnolia Press.

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