Host-plant acceptance by aphids: cues initiating reproduction

The host-plant acceptance behaviour of aphids was examined, in two aphid species, the bird cherry-oat aphid, Rhopalosiphum padi and the pea aphid, Acyrthosiphum pisum, to elucidate the recognition factors used to assess plant suitability for parthenogenetic reproduction. In addition, host-plant chemistry was investigated to study possible cues that initiated reproduction. The probing and parturition behaviour of R. padi on barley, Hordeum vulgare, or bird cherry leaves, Prunus padus, were monitored by electrical penetration graph (EPG) coupled with a simultaneous video recording. The autumn winged gynoparae and the summer winged virginoparae initiated reproduction on their host plants, P. padus and H. vulgare, respectively, before phloem contact occurred and these findings suggest that phloem contact is not necessary for host-acceptance decisions. Host acceptance behaviour of A. pisum, on susceptible and phloem-based resistant line of Medicago truncatula was monitored and found to be similar on both plant lines. The phloem-based resistance mechanism did not affect parturition behaviour indicating that reproduction is initiated prior to phloem contact. The results also imply that sign chemicals used as host recognition cues located in a peripheral tissue rather than in the phloem of host plants. Bioassays were employed to characterise the sign chemicals within host-plants of R. padi. It was found that virginoparae reproduced similarly on a neutral medium such as water or holidic diet as well as host-plant aqueous extract, which suggests that particular stimulants may be not involved in host-plant recognition by this generalist morph. On the other hand, aqueous extracts of bird cherry leaves specifically stimulated parturition in autumn gynoparae. Bioassay-guided chemical fractionation showed that at least five secondary metabolites appear to be involved in host recognition by gynoparae

Design Opportunities in Service-Product Combined Systems

This paper aims to examine recent research issues related to the integration of service and product in view of industrial design. Further, it attempts to identify new opportunities for further research regarding “product-servicization” vs. “service-productization”. In the continued efforts to provide the users with fuller experiences, one major trend is the blending of products and services. Much existing research seems to either present cases or propose frameworks regarding the ‘connection’, rather than ‘integration’ between products and services. Broadly, two major approaches seem to exist in this area: 1. product-servicization, 2. service-productization. The former generally indicates adding more services to existing products, whereas the latter generally refers to making services tangible and/or visible in the form of a product. However, findings of an extensive literature search conducted for this study suggest one important deficiency in dealing with service issues around the product: the ‘integration’ between the actual product design and service elements for supporting new service-product system. That is the rationale behind this research, an attempt to investigate the possibility for the integration of product design and service factors which could be embedded in the design of product itself in new service-product system. This paper is largely based on qualitative research. New design research opportunities are identified by qualitatively analyzing relevant literature, synthesizing the information and presenting some cases to support the main argument of the research. Design-led Service-Productization is not, and should not be re-arranging deck chairs on the Titanic. Rather, it should bring practical and tangible design issues related to new service-product system. Findings suggest that this approach could provide a new model of new product development integrated with a service scheme, which is a more proactive approach than “product-servicization”. Further development of this research could lead to establishing a framework for the Design-led Service-Product Integration. Keywords: Product-servicization; Industrial design; Service; Product; Integration</p

Lattice-coupled Antiferromagnet on Frustrated Lattices

Lattice-coupled antiferromagnetic spin model is analyzed for a number of frustrated lattices: triangular, Kagome, and pyrochlore. In triangular and Kagome lattices where ground state spins are locally ordered, the spin-lattice interaction does not lead to a static deformation of the lattice. In the pyrochlore structure, spin-lattice coupling supports a picture of the hexagon spin cluster proposed in the recent experiment[S. H. Lee et al. Nature, 418, 856 (2002)]. Through spin-lattice interaction a uniform contraction of the individual hexagons in the pyrochlore lattice can take place and reduce the exchange energy. Residual hexagon-hexagon interaction takes the form of a 3-states Potts model where the preferred directions of the spin-loop directors for nearby hexagons are mutually orthogonal

Do Japanese CEOs Matter?

In a country where individualism is not valued, we ask whether the CEO (shacho) of a Japanese corporation affects corporate behavior. To answer this question, we construct a shacho-firm matched panel data set in the period 1990 through 2002 of all listed 1,419 Japanese manufacturing firms and their 3,520 shachos. We utilize three distinct empirical methodologies to detect a shacho effect. First, we attempt to separate a firm-fixed effect from a shacho-fixed effect. We are unable to disentangle a shacho-fixed effect. Second, we examine whether the year of or the year after a shacho change was a turning point in the firm's 1990 to 2002 history of performance and policies. Our answer is generally no, even when the shacho change is non-routine. Third, we employ a classic event study to check whether the market thinks a shacho change is value-relevant. We do find a significant positive price response on the day a shacho change is announced, especially when the shacho change is non-routine. We are thus left to conclude that shachos do not matter in the Japanese corporation in this decade of a stagnant economy, though the market remains optimistic.