bluuebunny/crossref_metadata_2025_split huggingface dataset:
Contrasting responses to object orientation and illumination by the blowflies Chrysomya chloropyga and Lucilia sericata
Authors: Smith K.E. , Howard J.J. , Wall R. 
Published: October 2003

AbstractThe alighting response of two species of blowfly, Chrysomya chloropyga (Weidemann) and Lucilia sericata (Meigen) (Diptera: Calliphoridae), were considered in relation to the orientation and illumination of a flat, oblong visual object. A strong response to orientation was displayed by L. sericata with the greatest number alighting on the vertical object; there was no significant effect of orientation on the number of C. chloropyga which alighted. Both species alighted preferentially on the more strongly illuminated side of a vertical object. With the object horizontal and more strongly illuminated from below, C. chloropyga again landed on the most brightly illuminated side. In contrast, reducing the brightness on the upper surface of the horizontally‐suspended object reduced the number of L. sericata alighting on the upper surface but also reduced the overall catch, suggesting that for L. sericata the response to the illumination of a surface does not outweigh its response to its orientation. The implications of these results for the development of trapping technology for the monitoring or control of these economically important pest species is discussed.
Behavioural plasticity in support of a benefit for aggregation pheromone use in Drosophila melanogaster
Authors: Wertheim Bregje , Dicke Marcel , Vet Louise E.M. 
Published: October 2003

AbstractWe explored behavioural plasticity in the use of aggregation pheromone in the fruit fly Drosophila melanogaster Meigen (Diptera: Drosophilidae). Based on previous field observations, we formulated two hypotheses on a benefit of using aggregation pheromone for aggregated oviposition. One hypothesis concerns a benefit to the females themselves, where reduced harassment by males can enhance oviposition rate; the other concerns a benefit to their offspring, where larvae can exploit arduous substrates more efficiently. We derive contrasting expectations on the strength of the behavioural response to pheromone for substrates that differ in nutritional quality to larvae. High quality substrates relax the strength of larval competition, which allows for stronger aggregative responses of the females, but conversely, it may yield aggregation less necessary when the benefit is related to resource exploitation by the larvae. In indoor and outdoor dual choice set‐ups, we tested the behavioural responses of the adults to the aggregation pheromone with substrates of varying quality, and examined oviposition behaviour. The response of adults to the aggregation pheromone was strong and robust for low quality substrates, but significantly weaker for a high quality substrate. This supports the hypothesis on a benefit to the larvae. Females retained aggregation pheromones in the absence of oviposition substrates for at least 24 h. In the outdoor set‐up, substrate with aggregation pheromone received more than three times as many eggs as control substrates, and this was directly related to the number of adults that visited each substrate. Per capita, oviposition rates were not different for differently sized aggregations, and consequently, no evidence was found in support of the hypothesis on reduced harassment. The combination of aggregation pheromone possession and a mutualistic relationship with micro‐organisms for Drosophila and other insects is discussed.
Divergent responses of two cereal aphids to previous infestation of their host plant
Authors: Messina Frank J. , Taylor Rodrick , Karren Margaret E. 
Published: October 2003

AbstractWe examined the effects of prior infestation by the Russian wheat aphid [Diuraphis noxia (Mordvilko)] and the bird cherry‐oat aphid [Rhopalosiphum padi (L.)] on the subsequent feeding preferences and performance of each species. Aphid colonies fed and reproduced on wheat seedlings for five days and were then removed. After a period of plant recovery, we estimated aphid population growth and feeding preferences on control and previously infested plants. Previous infestation by D. noxia had no effect on the subsequent population growth of either aphid species. Previous infestation by R. padi reduced its own subsequent growth by 50%, but had little effect on the population growth of D. noxia. When presented leaves from control plants and D. noxia‐infested plants, D. noxia adults preferred to feed on leaves from control plants; R. padi adults showed no preference. Both aphids preferred leaves from control plants to those from R. padi‐infested plants. In free‐flight cages, alates of R. padi settled more often and produced more progeny on control plants than on plants previously infested by R. padi, but their rates of settling and reproduction were unaffected by prior D. noxia infestation. Together, our results suggest specificity in both the plant response to the two aphid species (plant quality for R. padi was lowered by prior R. padi infestation but not by D. noxia infestation) and in each aphid's response to the same modification of the host plant (infestation by R. padi reduced plant quality for itself but not for D. noxia). Effects of prior infestation on the feeding preferences of R. padi were correlated with effects on performance.
Girdling‐induced nutrient accumulation in above ground tissue of peanuts and subsequent feeding by Spissistilus festinus, the three‐cornered alfalfa hopper
Authors: Andersen Peter C. , Brodbeck Brent V. , Herzog Donald C. 
Published: October 2003

AbstractChanges in nutrient partitioning in stems and leaves of peanut (Arachis hypogaea L.) were examined after girdling of stems by Spissistilus festinus (Say) (Homoptera:Membracidae), the three‐cornered alfalfa hopper. Under field conditions amino acids increased more than 12‐fold in concentration in the 2 cm stem section above the girdle compared to below the girdle or control stems for newly formed girdles (less than 7–11 days). Asparagine and proline were the predominant amino acids, and increased 40‐ and 60‐fold, respectively, above the girdle compared to below the girdle. There was no buildup of nutrient assimilates for the older girdled stems that had callused (and presumably recovered from feeding injury). A time course from 1–11 days was followed under greenhouse conditions, and girdled regions remained enriched in sugars for one day and amino acids for four days after girdle formation. After girdle formation most S. festinus responded to nutrient sinks by feeding within 5 mm above the girdle. This behavior was most pronounced one day after girdle formation, but persisted for seven days after girdle formation. During this period a new girdle was often formed within 10 mm above the original girdle. Under field conditions, stems and leaves derived from stems that had sustained an early or late season girdle generally had a reduced dry weight, total nitrogen content, and total carbon content; however, significant differences did not always occur. Thus, although temporary changes occurred in nutrient partitioning in girdled stems, there appears to be longer term negative growth effects on leaves and stems.
Conditioning of appetitive behavior in the Hymenopteran parasitoid Microplitis croceipes
Authors: Wäckers Felix L. , Bonifay Claire , Lewis W. Joe 
Published: October 2003

AbstractWork on insect learning has made ample use of conditioned behaviors in single learning tasks. Parasitic wasps are particularly suited to study more complex learning processes, as they alternate between host searching and foraging for sugar sources. We here describe a set of behaviors that unambiguously represents sugar feeding in the Hymenopteran parasitoid Microplitis croceipes (Cresson) (Hymenoptera: Braconidae). Furthermore, we demonstrate that this parasitoid can be conditioned to exhibit these behaviors in response to odor stimuli previously associated with feeding. In conjunction with a previously described ovipositor probing response in this species, our findings constitute the first instance in which multiple conditioned behaviors representing feeding and reproduction have been identified for one insect species. This provides a valuable tool for the study of multiple task learning.
How do herbivorous insects cope with noxious secondary plant compounds in their diet?
Authors: Glendinning John I. 
Published: October 2003

AbstractHerbivorous insects use a variety of physiological mechanisms to cope with noxious (i.e., unpalatable and/or toxic) compounds in their food plants. Here, I review what is known about this coping process, focusing on one species of caterpillar, the tobacco hornworm (Manduca sexta). Herbivorous insects possess both preingestive (i.e., chemosensory) and postingestive response mechanisms for detecting plant secondary compounds. Stimulation of either class of detection mechanism inhibits feeding rapidly by reducing biting rate and/or bite size. This aversive response is highly adaptive during encounters with secondary plant compounds that are toxic. The insect's dilemma is that many harmless or mildly toxic compounds also activate the aversive response. To overcome this dilemma, herbivorous insects employ at least three mechanisms for selectively deactivating their aversive response to relatively harmless secondary plant compounds: (1) the presence of carbohydrates can mask the unpalatable taste of some secondary plant compounds; (2) prolonged dietary exposure to some unpalatable secondary plant compounds can initiate long‐term adaptation mechanisms in the peripheral and central gustatory system; and (3) dietary exposure to toxic compounds can induce production of P450 detoxication enzymes. Thus, herbivorous insects utilize an integrated suite of physiological mechanisms to detect potentially toxic compounds in foods, and then selectively adapt to those that do not pose a serious threat to their growth and survivorship.
Interspecific competition between the polyembryonic wasp Copidosoma floridanum and the gregarious endoparasitoid Glyptapanteles pallipes
Authors: Utsunomiya Akio , Iwabuchi Kikuo 
Published: October 2003

AbstractWe examined interspecific competition between the egg‐larval polyembryonic parasitoid Copidosoma floridanum (Hymenoptera: Encyrtidae) and the gregarious larval endoparasitoid Glyptapanteles pallipes (Hymenoptera: Braconidae). Approximately 72% of multiparasitized Acanthoplusia agnata (Lepidoptera: Noctuidae) produced C. floridanum adults, 14% produced G. pallipes adults, and 14% died without producing any parasitoids. Development was delayed and the rate of weight gain was reduced in multiparasitized hosts that produced C. floridanum compared with singly‐parasitized hosts. In contrast, only weight was reduced in multiparasitized hosts that produced G. pallipes adults. Compared with single parasitism, the brood size of wasps emerging from multiparasitized hosts was reduced in both species. The percentage of hosts containing precocious larvae of C. floridanum, which are considered to be soldiers, did not increase in response to parasitization by G. pallipes. However, developmental cessation and death of G. pallipes eggs and larvae may be closely related to the number of coexisting precocious larvae.
Truth
Authors: Austin J. L. , Urmson J. O. , Warnock G. J. 
Published: October 2003

Abstract
Deals with the question of whether there is a use of ‘is true’ that is the primary or generic name for that which at bottom we are always saying ‘is true’. Austin discusses the views that truth is primarily a property of beliefs and of true statements. He goes on to argue that the word ‘true’ denotes the validity of an intended (or expected) correspondence between a representation and what it represents, and dismantles confusions about the meaning of the words that underlie such a view, such as ‘fact that’ and ‘corresponds’.
Ifs and Cans
Authors: Austin J. L. , Urmson J. O. , Warnock G. J. 
Published: October 2003

Abstract
Criticises G. E. Moore’s highly influential proposal that ascriptions of agent ability implying freedom of choice or action, what the agent could do, are analyzable as conditional statements regarding what the agent would do under certain circumstances. Austin objects against Moore that some uses of ‘if’ are non-conditional and goes on to examine the uses of these non-conditional cases. Moore’s proposal also lies at the heart of some compatibilist theories of free will and determinism. Austin argues determinism to be a pseudo-problem, so long as it remains a notion that is not itself clear cut.
An Approach for Determining Optimal Product Sampling for the Diffusion of a New Product
Authors: Jain Dipak , Mahajan Vijay , Muller Eitan 
Published: October 2003

Free samples are an effective means for introducing and promoting a new product. However, product sampling is also expensive. As a result, careful consideration must be given to the question of how many samples should be distributed. To encourage product adoption in any target market, a company needs to determine the “right” amount of sampling. In other words, a firm needs to determine the optimal number of samples that must be available for trial by the innovators, early adopters, and other key consumers who influence the adoption rate of the new product. With too few samples, the product might not reach enough of these key consumers to generate the word‐of‐mouth recommendations necessary for market success. On the other hand, offering too many free samples is a waste of a company's resources.Dipak Jain, Vijay Mahajan, and Eitan Muller propose a framework for determining the optimal levels of product sampling. In addition to identifying the upper bounds for the sampling levels of both durable and nondurable products, their model identifies the optimal size of product sampling based on such parameters as the coefficients of innovation and imitation, market potential, discount rate, and gross margin.Several observations are made regarding the relationships between the optimal sampling level and the various parameters used in the model. For example, a high sampling level is not appropriate for a product with a high coefficient of innovation. On the other hand, if a product has a high coefficient of imitation, the sampling level should be high because a significant number of trials are necessary for word of mouth to be effective. High sampling levels are also indicated by a high discount rate or gross margin.For durable goods, the optimal level of neutral sampling (i.e., sampling that does not specifically target innovators and early adopters) rarely exceeds 5%, and the maximum level is 7%. The optimal target sampling level is always higher than the corresponding neutral case, but, in most cases, only marginally so. For the parameter ranges chosen in this article, the maximum level for target sampling is approximately 9%. However, it is important to note that the theoretical upper bounds are no more than benchmarks for the maximum possible level of sampling. In practical situations, the optimal level may be considerably lower than these upper bounds. In such cases, the actual values will depend on the values for the various parameters used in the model.
Measuring New Product Success: The Difference that Time Perspective Makes
Authors: Hultink Erik Jan , Robben Henry S. J. 
Published: October 2003

Management is often criticized for overemphasizing short‐term profits at the expense of long‐term growth. On the other hand, although numerous studies have explored the factors underlying new product success and failure, such studies rarely distinguish between short‐ and long‐term success. In fact, little research has been conducted to explore the relationship between a company's time perspective and its choice of criteria for measuring new product success. For that matter, little consensus exists as to just what we mean by the term success.Expanding on work done by a PDMA task force on measurement of new product success and failure, Erik Jan Hultink and Henry S.J. Robben identify 16 core measures of new product success. In a survey of large Dutch companies, they explore managers' perceptions of new product success, hypothesizing that the importance attached to each of the 16 core measures depends on the company's time perspective. For example, they propose that criteria such as development cost and speed‐to‐market are more important in the short term, and return‐on‐investiment (ROI) is more important in the long term.The study also examines the type of market served, the innovation strategy, and the perceived innovativeness of the company's products. It is hypothesized that these factors will influence the importance the company attaches to the core measures of new product success. For example, it is expected that speed‐to‐market is probably more important for technological innovators than for fast imitators or cost minimizers.The findings support the hypothesis that the firm's time perspective influences the perceived importance of the core measures of success. For the short term, the respondents emphasize product‐level measures such as speed‐to‐market and whether the product was launched on time. In the long term, the focus is on customer acceptance and financial performance, including attaining goals for profitability, margins, and ROI. Four factors are perceived as being equally important for short‐term and long‐term success: customer satisfaction, customer acceptance, meeting quality guidelines, and product performance level. Customer satisfaction was found to be the most important measure, regardless of a company's time perspective.Contrary to expectations, the perceived importance of the 16 core measures does not differ on the basis of the type of market, the innovation strategy, or the product's perceived innovativeness. In addition, the firm's functional orientation—technology push or market pull—does not affect the importance attached to the core measures of new product success.
How Canon and Sony Drive Product Innovation Through Networking and Application‐Focused R&D
Authors: Harryson Sigvald J. 
Published: October 2003

To ensure the ongoing vitality of a company's product offerings, R&D professionals must play a daunting array of roles. The already rapid, yet still accelerating, pace of technological change may lead some companies to devote more resources to intensive internal research efforts. However, the shift toward global competition demands a more market‐oriented focus from R&D; clear understanding of current and potential markets must drive R&D efforts. And efficient, cost‐effective manufacturing of new products requires an R&D organization that understands and interacts effectively with the production department. How does a company create an environment in which its R&D organization comprises market‐savvy, production‐friendly experts in diverse technologies?With case studies of R&D efforts at Canon and Sony, Sigvald Harryson identifies and illustrates the key mechanisms that these companies use to foster product innovation. His examples show how Canon and Sony use a combination of external and internal networking mechanisms to identify and acquire key technologies and related skills, gain market knowledge, improve the results of internal R&D efforts, and ensure the successful transfer of these results to efficient production processes.He identifies four key mechanisms underlying successful product innovation at Canon and Sony: strategic training and job rotation for engineers, application‐driven R&D, direct transfer of development teams from R&D to production, and extensive networking with external centers of excellence and key suppliers. At Canon, the initial training program for all researchers and engineers begins with three months of work on a production line. Sony's new researchers and development engineers spend one month in production. Both companies also give their new R&D professionals three months of training in sales and marketing.The emphasis on market‐driven research at both companies means that researchers have identified some commercial application for almost every initial research proposal that gains approval. Neither company treats research as a long‐term assignment; almost all engineers at both companies eventually move from the labs to production. And rather than viewing this job rotation strategy as a drain on the technological expertise in their labs, both companies rely on strong external networks with key suppliers and university‐based researchers as important sources for acquiring new technologies and the competencies needed to support them.
Risky Business or Competitive Power? Supplier Involvement in Japanese Product Design
Authors: Wasti S. Nazli , Liker Jeffrey K. 
Published: October 2003

Notwithstanding the alleged risks of outsourcing design work, leading manufacturers in the Japanese automotive industry collaborate closely with their key suppliers. Despite widespread recognition of the effectiveness of these close‐knit supplier networks, however, little research exists on the factors that affect the purchase of design work from suppliers.S. Nazli Wasti and Jeffrey K. Liker fill this gap by exploring the factors that affect Japanese automotive firms' purchase of design work from their component suppliers. Using data from a survey of 122 Japanese automotive component suppliers, their study addresses two key questions. First, what factors lead Japanese buyers to involve some suppliers heavily in design while giving others relatively little control over design decisions? And second, does the Japanese practice of involving suppliers in design offer performance benefits? The study focuses on first‐tier suppliers of parts, assemblies, and complete subsystems (e.g., audio, fuel and emissions, heating and air conditioning). The study does not include suppliers of raw materials and chemicals, assembly and processing equipment, indirect materials, tooling and dies, computers and software, or engineering and business consulting services.The study breaks down the broad concept of supplier involvement in design work into three measurable elements: the extent to which the supplier influences decision‐making during the early stages of product development; the amount of control the buyer retains over the design; and the frequency of design‐related communication between the buyer and the supplier. Factors that have a positive effect on the level of supplier involvement among the companies studied include technological uncertainty of the component and the supplier's in‐house technical capabilities. For companies in the study, the level of competition in the supplier market has a negative effect on the degree of supplier involvement in design.The responses indicate that supplier involvement offers performance benefits for both the supplier and the buyer. For the supplier firms studied, increased involvement in the design process permits greater focus on design for manufacturability (DFM). And of course, supplier‐generated design improvements clearly benefit the buyers, allowing these firms to capitalize on the experience and the insight that their suppliers have regarding the parts that they supply.