This study examines the optimal pricing and production strategy of a closed-loop supply chain consisting of a manufacturer, a recycler, and consumers. Considering the cannibalization and promotion effects of remanufac...This study examines the optimal pricing and production strategy of a closed-loop supply chain consisting of a manufacturer, a recycler, and consumers. Considering the cannibalization and promotion effects of remanufactured products on new and secondhand products, we constructed Stackelberg game models under different scenarios. We analyze the impact of the changes in the two effects on the optimal prices and production strategies of the manufacturer and recycler, as well as their countermeasures. We find that (i) how the cannibalization and promotional effects influence the manufacturer and the recycler's pricing and production strategies differ under different scenarios;(ii) when the two effects exceed a threshold, the manufacturer abandons new or remanufactured products, and the recycler prefers to stop production on its new products or continue to remanufacture products;and (iii) the two effects always reduce the profits of the manufacturer and increase the profits of the recycler.展开更多
Although widely thought to be aggressive, solitary,and potentially cannibalistic, some spider species have evolved group-living behaviors. The distinct transition provides the framework to uncover groupliving evolutio...Although widely thought to be aggressive, solitary,and potentially cannibalistic, some spider species have evolved group-living behaviors. The distinct transition provides the framework to uncover groupliving evolution. Here, we conducted a comparative transcriptomic study and examined patterns of molecular evolution in two independently evolved group-living spiders and twelve solitary species. We report that positively selected genes among groupliving spider lineages are significantly enriched in nutrient metabolism and autophagy pathways. We also show that nutrient-related genes of group-living spiders convergently experience amino acid substitutions and accelerated relative evolutionary rates. These results indicate adaptive convergence of nutrient metabolism that may ensure energy supply in group-living spiders. The decelerated evolutionary rate of autophagy-related genes in group-living lineages is consistent with an increased constraint on energy homeostasis as would be required in a group-living environment. Together, the results show that energy metabolic pathways play an important role in the transition to group-living in spiders.展开更多
The present study examines the inherent flexibility in the feeding responses of S. infraimmaculata larvae to various breeding places. In addition, the study examines the hypothesis that in dry conditions, the water br...The present study examines the inherent flexibility in the feeding responses of S. infraimmaculata larvae to various breeding places. In addition, the study examines the hypothesis that in dry conditions, the water breeding places are the limiting factor for the survival and completion of the life cycle of populations of S. infraimmaculata. In the breeding sites, the food for larvae is not available, and cannibalism is the specific adaptation for larvae to grow and complete metamorphosis. S. infraimmaculata larvae feed on various invertebrates in different habitats, and cannibalism involves the adaptation to breeding places where food is not available. The growth only by cannibalism as the only way to adapt to these habitats because no food is found in breeding places at the southern border of its distribution is described here for the first time, not only in salamanders but in other animals as well.展开更多
As one of the representative contemporary Asian American poets, Li-Young Lee in his two poetry collections entitled Rose and The Cify in Which 1Love You, recuperates his fragmented family history of immigration, and r...As one of the representative contemporary Asian American poets, Li-Young Lee in his two poetry collections entitled Rose and The Cify in Which 1Love You, recuperates his fragmented family history of immigration, and reconstructs a dynamic relationship with remembrance of the past that writes about him and defines his sense of self. This paper from the multicultural perspective argues that understanding the past through understanding his godlike father, Lee not only negotiates the formation of his subjectivity and identity, but also establishes a spiritual origin and belonging not merely with his ethnic communities but with all the immigrants as well. The paper finds that the strategy he employs in his articulation of his self is marked by his excellent execution of poetic epiphany, and metonymic cannibalism.展开更多
The launching of a new product is an essential strategy for the survival and success of a company. However, in certain cases, it can reduce the results obtained by other products of the same company. This fact is nam...The launching of a new product is an essential strategy for the survival and success of a company. However, in certain cases, it can reduce the results obtained by other products of the same company. This fact is named "cannibalism". Following by a review of the literature on cannibalism between goods, this paper outlines a conceptual approach, showing the way it happens, its impacts, and the possibility of its uses as a marketing tool. A new product should, wherever possible, be carefully designed to avoid cannibalizing old products, unless this process is carefully planned. Concludes that creating and launching of new products are critical to companies who want to stand out next to their markets and need to survive over time. A lot of new products launched each year, coupled with the fact that most are line extensions already worked by companies, so we assume that the occurrence of cannibalism is common, or that a significant amount of resources are designed to prevent or dilute it. There is a high probability of transfer of results obtained by established products to new products, since similarity between展开更多
Good brand name translation involves knowledge and expertise from many disciplines,such as linguistics,translation studies,marketing,aesthetics,psychology,law,etc.It is really an interdisciplinary practice that requir...Good brand name translation involves knowledge and expertise from many disciplines,such as linguistics,translation studies,marketing,aesthetics,psychology,law,etc.It is really an interdisciplinary practice that requires strenuous research and experience.In addition,the research methodology thereof is also quite problematic.This paper aims at bringing a latest translation theory—cannibalism into brand name translation and test its applicability in brand name translation practice.展开更多
At the end of the eighteenth century in Britain,due to the development of capitalism,money has become more and more important.Jane Austen describes in the Sense and Sensibility that under the influence of money,people...At the end of the eighteenth century in Britain,due to the development of capitalism,money has become more and more important.Jane Austen describes in the Sense and Sensibility that under the influence of money,people's values have become dis⁃torted,such as some have become family cannibalism,and some have become betrayers of love.At the same time,Austen also ex⁃presses her attitude towards money which gives us a lot of enlightenment.展开更多
Maternal care is critically important for the survival of offspring in various animals.Spiders in the family Lycosidae are known for their hunting ability and maternal care behaviors.Predation on newly hatched spiderl...Maternal care is critically important for the survival of offspring in various animals.Spiders in the family Lycosidae are known for their hunting ability and maternal care behaviors.Predation on newly hatched spiderlings(pulli)by mother spiders decreases when they come into contact,and they carry the pulli on their dorsal surface.However,the factors inducing maternal care in lycosid spiders have not been elucidated.In this study,we investigated maternal care in Pardosa pseudoannulata(Araneae,Lycosidae)females.We proposed that the physical interaction between pulli and mother spiders induces maternal care via m-aminophenylacetylene(m-A),a novel regulator of maternal care.The presence of pulli on the dorsal abdomen of non-mother spiders suppressed pulli predation and in-creased the pulli-carrying rate,and the absence of pulli on the mother spiders increased pulli predation and decreased the pulli-carrying rate.The compound m-A was abundant in mother spiders,and it could be induced in non-mother spiders when they carried pulli.The topical application of m-A to non-mother spiders and m-A injection decreased pulli predation and increased the pulli-carrying rate,respectively;these findings indicate that m-A in both internal tissues and the integument is required for the induction of mater-nal care behavior,and the interaction between pulli and females induces the production of m-A.In-depth study of the regulatory mechanism of maternal care will enhance our understanding of spider biology and behavior.展开更多
With the rapid development of e-Commerce and takeaway platforms, retailers have gradually developed multi-channel operations. However, limited empirical studies explored the effects of an online channel offered by tak...With the rapid development of e-Commerce and takeaway platforms, retailers have gradually developed multi-channel operations. However, limited empirical studies explored the effects of an online channel offered by takeaway platforms on the store performance. Does an online channel addition have a synergy effect or a cannibalization effect on store performance? We empirically investigate these effects by analyzing a large dataset including diverse samples collected from multiple retailers across various regions. The dataset includes 2115 stores across 25 retailers for 10 months that includes two types of retail formats and covers 16 provinces and 21 cities of China. We study the impacts of the newly introduced online channel on the incumbent offline channel and the overall store performance.The empirical results reveal that the online channel addition mainly has a synergy effect. Specifically,for the overall store, it has a positive effect on the sales and product variety, whereas it has a negative effect on the basket size. Surprisingly, an online channel addition also has a positive effect on the offline sales. Our study adds novel values to multi-channel retailing literature by empirically researching the cannibalization and synergy effect of a new type of online channel, offered by takeaway platforms. It can provide insights for retail enterprises who are interested in introducing O2 O model.展开更多
In technology-intensive markets, it is a common strategy for companies to develop long-term multiple generation product lines instead of releasing consecutive single products. Even though this strategy is more profita...In technology-intensive markets, it is a common strategy for companies to develop long-term multiple generation product lines instead of releasing consecutive single products. Even though this strategy is more profitable than sequentially introducing single product generations, it can also result in inter-product line cannibalization. Cannibalization of multiple-generation product lines is a complex problem that needs to be taken into account at the early product line planning stage in order to sustain long-term profitability. In this paper, we propose an agent-based model that can simulate the potential cannibalization scenarios within a multiple-generation product line. We view a multiple-generation product line (MGPL) as complex adaptive system where each product generation in the MGPL adjusts its sales price over time based on the shifts in the market demand. The proposed model provides insights into how various pricing strategies impact the overall lifecycle profitability of MGPL and can be used to assist companies in developing appropriate dynamic pricing strategies at the early product line planning stages.展开更多
Ecdysis is a comm on phe nomenon that happe ns throughout the life phase of the giant freshwater prawn Macrobrachium rosenbergii.It is vital to better understand the correlation between cannibalism and biochemical com...Ecdysis is a comm on phe nomenon that happe ns throughout the life phase of the giant freshwater prawn Macrobrachium rosenbergii.It is vital to better understand the correlation between cannibalism and biochemical compound that exists during the moulting process.The objective of the present study was to determine the amino acid profile released by M.rosenbergii during the ecdysis process that promotes cannibalism.To accomplish this,changes in amino acid levels(total amino acid(TAA)and free amino acid(FAA))of tissue muscle,exoskeleton,and sample water of culture medium from the moulting(E-stage)and non-moulting(C-stage)prawns were analysed using highperformanee liquid chromatography(HPLC).Comparison study revealed that among the TAA compounds,proline and sarcosine of tissues from moulting prawn were found at the highest levels.The level of FAA from water that contains moulting prawns(E-stage)was dominated by tryptophan and proline.Significant values obtained in the present study suggested that these amino acid compounds act as a chemical cue to promote cannibalism in M.rosenbergii during ecdysis.The knowledge of compositions and compounds that were released during the moulting process should be helpful for better understanding of the mechanism and chemical cues that play roles on triggering cannibalism,and also for future dietary man ipulati on to improve feeding efficie ncies and feeding man agement,which in directly impacts productivity and profitability.展开更多
Cannibalism is an intriguing life history trait, that has been considered primarily in the predator, in predator-prey population models. Recent experimental evidence shows that prey cannibalism can have a significant ...Cannibalism is an intriguing life history trait, that has been considered primarily in the predator, in predator-prey population models. Recent experimental evidence shows that prey cannibalism can have a significant impact on predator-prey population dyna- mics in natural communities. Motivated by these experimental results, we investigate a ratio-dependent Holling-Tanner model, where cannibalism occurs simultaneously in both the predator and prey species. We show that depending on parameters, whilst prey or predator cannibalism acting alone leads to instability, their joint effect can actually stabilize the unstable interior equilibrium. Furthermore, in the spatially explicit model, we find that depending on parameters, prey and predator cannibalism acting jointly can cause spatial patterns to form, while not so acting individually. We discuss ecologicalconsequences of these findings in light of food chain dynamics, invasive species control and climate change.展开更多
Wood frog Lithobates sylvaticus tadpoles develop in temporary wetlands where high population densities can force tadpoles into aggregations that intensify competition and can lead to cannibalism. However, chemical ala...Wood frog Lithobates sylvaticus tadpoles develop in temporary wetlands where high population densities can force tadpoles into aggregations that intensify competition and can lead to cannibalism. However, chemical alarm cues released from injured conspecifics could also dissuade cannibalism. The purpose of this study was to test mechanisms that may influence can- nibalistic behaviour. We tested whether the tendency of tadpoles to consume conspecifics would increase with the presence of competition and/or cues of profitable diets. Tadpoles placed in 1L experimental containers were tested for feeding initiation times of multiple diets, including conspecific tissues and conspecific tissues combined with chemical cues from the alternative diets (brine shrimp and comrneal). Tadpoles were tested in the presence and absence of a competitor, and at multiple times over the course of the study. Tadpoles exhibited an altered response to diets over time; however the presence of a competitor reduced re- sponse times to all diets including conspecific tissues. Similarly, the presence of specific diets also reduced the response time of tadpoles to conspecific tissues. These results suggest competition among feeding tadpoles could result in aggressive behaviour leading to indiscriminate predation and cannibalism [Current Zoology 60 (5): 571-580, 2014 ].展开更多
Previous observations of cannibalism have been made in the aphid Acyrthosiphon pisum (L.): this article seeks to quantify factors contributing to such be- haviors. We observed and quantified the responses of a numb...Previous observations of cannibalism have been made in the aphid Acyrthosiphon pisum (L.): this article seeks to quantify factors contributing to such be- haviors. We observed and quantified the responses of a number of clones and life stages to varying levels of starvation, in the form of increasingly desiccated Vicafaba L. plants (receiving 50, 25, or 10 mL every second day) or a complete absence of host plant. We found that, while the longest incidences of cannibalism are carried out by juveniles (F = 3.45, P = 0.019, df = 3) and targeted at adults, the starvation treatments had the most significant effect on the prevalence of cannibalism in mature A. pisum (F ---- 2.24, P = 0.025, df = 9). Furthermore, there was no difference between the prevalence or dura- tion of cannibalistic activities within and between different clones (P 〉 0.05 in all cases), though juveniles were more likely to target unrelated aphids (V = 6 112, P = 0.011), and spent more time feeding on aphids from the same culture (V = 6 062, P = 0.018).展开更多
Cannibalism is common in spiders.Wolf spider(Lycosidae)females,which exhibit extensive maternal care,have been reported to cannibalize less when they are carrying egg sacs and juveniles.In a laboratory experiment,we d...Cannibalism is common in spiders.Wolf spider(Lycosidae)females,which exhibit extensive maternal care,have been reported to cannibalize less when they are carrying egg sacs and juveniles.In a laboratory experiment,we demonstrated that cannibalism of early-instar spiderlings(EIS)by a wolf spider(Pardosa pseudoannulata)mother was almost completely inhibited when she was carrying spiderlings.Compared with virgin and mated-females,mother spiders tolerated more and predated fewer spiderlings,including gregarious pulli and newly dispersed spiderlings(NDS).Cannibalism of EIS by females during their reproductive period exhibited a V-shaped pattern,with a gradual decrease from the egg sac-carrying to pulli-carrying(PC)stage,and a recovery from the PC stage to post-reproductive(PR)stage.Notably,there was 0 cannibalism at the PC stage.PC females exhibited no interest in pulli,while PR females were attracted to and predated pulli and NDS as they did their natural prey,Nilaparvata lugens.Interestingly,PC females captured and released NDS in a foraging assay,although attraction was observed from olfactometer measurements.PC mothers possessed a cuticular volatile profile that was closer to that of pulli and NDS than to that of PR females.Moreover,NDS cuticular extract provoked an electrophysiological response in legs of PC females.Therefore,cuticular compound-mediated chemical communication may be involved in inhibiting cannibalism of EIS by spider mothers,and especially in eliminating cannibalism by PC mothers.Future studies will aim to characterize the specific cuticular compounds and chemoreception mechanism in females,which will facilitate our understanding of intraspecific recognition and cannibalism in spiders.展开更多
Colony cages for natural mating have been applied on many layer breeder farms.However,feather pecking and cloacal cannibalism are considered as prominent problems for these systems.This study aimed to investigate the ...Colony cages for natural mating have been applied on many layer breeder farms.However,feather pecking and cloacal cannibalism are considered as prominent problems for these systems.This study aimed to investigate the effects on feather pecking and vent pecking behaviors by providing layer breeders with nest boxes(0.90 m L×0.40 m W×0.60 m H)in colony cages for natural mating(4.80 m L×1.20 m W×0.71 m H).Video recording and artificial observation were adopted.The results showed that the usage of nest boxes gradually increased from the beginning of nest boxes providing at the age of 37 weeks to the end of the experiment at the age of 55 weeks.The utilization rates of nest boxes were 36.75%,44.75%and 50.38%at the ages of 41 weeks,47 weeks and 53 weeks,respectively.The hens in the cages without nest boxes showed significantly more frequent gentle feather pecks(both given and received)than hens in the cages with nest boxes at the ages of 41 weeks,47 weeks and 53 weeks.A decreasing trend of gentle feather pecking frequency(both given and received)was found with the increasing age for both the two groups.No significant difference was found in the number of given or received severe feather pecks at the age of 41 weeks.The hens in the cages without nest boxes showed a significantly higher frequency of given and received severe feather pecks than hens in the cages with nest boxes at the ages of 47 weeks and 53 weeks(p<0.05).Both cannibalistic injury occurrence and mortality rate in the cages with nest boxes were significantly lower than those in the cages without nest boxes.In conclusion,providing nest boxes in colony cages for natural mating could decrease abnormal pecking behaviors and improve animal welfare conditions of layer breeders.展开更多
Cannibalism is a life trait occurring in a wide variety of species.To describe the population dynamics of cannibalistic species,we develop a stage-structured population model in which axJults prey on juveniles with a ...Cannibalism is a life trait occurring in a wide variety of species.To describe the population dynamics of cannibalistic species,we develop a stage-structured population model in which axJults prey on juveniles with a Holling type I functional response.We make a rigorous analysis of the global dynamics in the model.The results of theoretical analysis show that the model has no boundary equilibrium other than the extinction one since juveniles and adults are cooperative(adults reproduce juveniles and juveniles grow into adults).Under certain conditions,the model has multiple interior equilibria and exhibits several types of bistable dynamics,in which different initial densities of juveniles and adults produce different long-term outcomes.展开更多
While juvenile cannibalism plays an important role in the evolution of organisms in natural populations,it is a serious problem in aquaculture.A number of genetic and environmental factors result in different rates of...While juvenile cannibalism plays an important role in the evolution of organisms in natural populations,it is a serious problem in aquaculture.A number of genetic and environmental factors result in different rates of cannibalism.Whether there is kin recognition in juvenile cannibalism in fish is poorly understood.We studied cannibalism and kinship recognition in juveniles of Asian seabass using molecular parentage analysis with polymorphic microsatellites.In the three mass crosses,under an ordinary feeding scheme without size grading,the rate of juvenile loss due to cannibalism was 1.08% per day.In the group without feeding for 24 h,2.30%±0.43% of offspring per day were lost within 24 h due to cannibalism.We detected that juveniles avoided cannibalizing their siblings when they were not hungry,whereas cannibalism among siblings increased when they were hungry.These data suggest that there is kin discrimination in fish cannibalism.Raising genetically closely related offspring in the same tanks and appropriate levels of feeding may reduce the rate of cannibalism.We hypothesized that the chemical cues for kin discrimination might be secreted by fish skins.To test this hypothesis,we analyzed gene expression profiles in the skins of juveniles under slightly and very hungry conditions using RNA sequencing and bioinformatics analysis.Genes differently expressed under slightly and very hungry conditions were identified.Among them,genes from the trypsin family were significantly downregulated under starved conditions,suggesting that they may play a role in kin discrimination.展开更多
The Diary of A Madman (Kuangren r/j/), Lu Xun's first well-known short stoW and the alleged first modem short stow in vernacular Chinese, is famous for its first-person narrative by an intellectual that is sufferin...The Diary of A Madman (Kuangren r/j/), Lu Xun's first well-known short stoW and the alleged first modem short stow in vernacular Chinese, is famous for its first-person narrative by an intellectual that is suffering from a persecution complex. As acknowledged by Lu Xun himself and argued by most scholars, this short stoW was influenced by Gogol's homonymic short stow, but has developed more profound melancholy and indignation. However, as my paper demonstrates, this perspective neglects the role of Japan as an intermediary in the transculturation of madness. First, Lu Xun's initial encounter with Gogol's Diary of A Madman was through his reading of Futabatei Shimei's translation in the Japanese magazine Ky6mi. Second, the framed narrative and contrasting styles of Lu Xun's short stow, which are not features of Gogol's, might also be due to the inspiration from the Japanese genbun itchi movement in the Meiji period. Third, and most importantly, cannibalism, a major theme in Lu Xun's Diary of A Madman, was arguably shaped by the heated discussion in Japan on national character and cannibalism. My paper will trace the double origin of the depiction of madness and cannibalism in Lu Xun's work and illustrate the importance of the role of Japan in the transculturation of the stow of a madman.展开更多
文摘This study examines the optimal pricing and production strategy of a closed-loop supply chain consisting of a manufacturer, a recycler, and consumers. Considering the cannibalization and promotion effects of remanufactured products on new and secondhand products, we constructed Stackelberg game models under different scenarios. We analyze the impact of the changes in the two effects on the optimal prices and production strategies of the manufacturer and recycler, as well as their countermeasures. We find that (i) how the cannibalization and promotional effects influence the manufacturer and the recycler's pricing and production strategies differ under different scenarios;(ii) when the two effects exceed a threshold, the manufacturer abandons new or remanufactured products, and the recycler prefers to stop production on its new products or continue to remanufacture products;and (iii) the two effects always reduce the profits of the manufacturer and increase the profits of the recycler.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB31000000) to S.Q.L。
文摘Although widely thought to be aggressive, solitary,and potentially cannibalistic, some spider species have evolved group-living behaviors. The distinct transition provides the framework to uncover groupliving evolution. Here, we conducted a comparative transcriptomic study and examined patterns of molecular evolution in two independently evolved group-living spiders and twelve solitary species. We report that positively selected genes among groupliving spider lineages are significantly enriched in nutrient metabolism and autophagy pathways. We also show that nutrient-related genes of group-living spiders convergently experience amino acid substitutions and accelerated relative evolutionary rates. These results indicate adaptive convergence of nutrient metabolism that may ensure energy supply in group-living spiders. The decelerated evolutionary rate of autophagy-related genes in group-living lineages is consistent with an increased constraint on energy homeostasis as would be required in a group-living environment. Together, the results show that energy metabolic pathways play an important role in the transition to group-living in spiders.
文摘The present study examines the inherent flexibility in the feeding responses of S. infraimmaculata larvae to various breeding places. In addition, the study examines the hypothesis that in dry conditions, the water breeding places are the limiting factor for the survival and completion of the life cycle of populations of S. infraimmaculata. In the breeding sites, the food for larvae is not available, and cannibalism is the specific adaptation for larvae to grow and complete metamorphosis. S. infraimmaculata larvae feed on various invertebrates in different habitats, and cannibalism involves the adaptation to breeding places where food is not available. The growth only by cannibalism as the only way to adapt to these habitats because no food is found in breeding places at the southern border of its distribution is described here for the first time, not only in salamanders but in other animals as well.
文摘As one of the representative contemporary Asian American poets, Li-Young Lee in his two poetry collections entitled Rose and The Cify in Which 1Love You, recuperates his fragmented family history of immigration, and reconstructs a dynamic relationship with remembrance of the past that writes about him and defines his sense of self. This paper from the multicultural perspective argues that understanding the past through understanding his godlike father, Lee not only negotiates the formation of his subjectivity and identity, but also establishes a spiritual origin and belonging not merely with his ethnic communities but with all the immigrants as well. The paper finds that the strategy he employs in his articulation of his self is marked by his excellent execution of poetic epiphany, and metonymic cannibalism.
文摘The launching of a new product is an essential strategy for the survival and success of a company. However, in certain cases, it can reduce the results obtained by other products of the same company. This fact is named "cannibalism". Following by a review of the literature on cannibalism between goods, this paper outlines a conceptual approach, showing the way it happens, its impacts, and the possibility of its uses as a marketing tool. A new product should, wherever possible, be carefully designed to avoid cannibalizing old products, unless this process is carefully planned. Concludes that creating and launching of new products are critical to companies who want to stand out next to their markets and need to survive over time. A lot of new products launched each year, coupled with the fact that most are line extensions already worked by companies, so we assume that the occurrence of cannibalism is common, or that a significant amount of resources are designed to prevent or dilute it. There is a high probability of transfer of results obtained by established products to new products, since similarity between
文摘Good brand name translation involves knowledge and expertise from many disciplines,such as linguistics,translation studies,marketing,aesthetics,psychology,law,etc.It is really an interdisciplinary practice that requires strenuous research and experience.In addition,the research methodology thereof is also quite problematic.This paper aims at bringing a latest translation theory—cannibalism into brand name translation and test its applicability in brand name translation practice.
文摘At the end of the eighteenth century in Britain,due to the development of capitalism,money has become more and more important.Jane Austen describes in the Sense and Sensibility that under the influence of money,people's values have become dis⁃torted,such as some have become family cannibalism,and some have become betrayers of love.At the same time,Austen also ex⁃presses her attitude towards money which gives us a lot of enlightenment.
基金The work was supported by National Natural Foundation of China(grant number 31972296,31830075,and 32172482).
文摘Maternal care is critically important for the survival of offspring in various animals.Spiders in the family Lycosidae are known for their hunting ability and maternal care behaviors.Predation on newly hatched spiderlings(pulli)by mother spiders decreases when they come into contact,and they carry the pulli on their dorsal surface.However,the factors inducing maternal care in lycosid spiders have not been elucidated.In this study,we investigated maternal care in Pardosa pseudoannulata(Araneae,Lycosidae)females.We proposed that the physical interaction between pulli and mother spiders induces maternal care via m-aminophenylacetylene(m-A),a novel regulator of maternal care.The presence of pulli on the dorsal abdomen of non-mother spiders suppressed pulli predation and in-creased the pulli-carrying rate,and the absence of pulli on the mother spiders increased pulli predation and decreased the pulli-carrying rate.The compound m-A was abundant in mother spiders,and it could be induced in non-mother spiders when they carried pulli.The topical application of m-A to non-mother spiders and m-A injection decreased pulli predation and increased the pulli-carrying rate,respectively;these findings indicate that m-A in both internal tissues and the integument is required for the induction of mater-nal care behavior,and the interaction between pulli and females induces the production of m-A.In-depth study of the regulatory mechanism of maternal care will enhance our understanding of spider biology and behavior.
基金Supported by Beijing Natural Science Foundation(9212020)National Natural Science Foundation of China(72172145,71932002)the Fundamental Research Funds for the Central Universities。
文摘With the rapid development of e-Commerce and takeaway platforms, retailers have gradually developed multi-channel operations. However, limited empirical studies explored the effects of an online channel offered by takeaway platforms on the store performance. Does an online channel addition have a synergy effect or a cannibalization effect on store performance? We empirically investigate these effects by analyzing a large dataset including diverse samples collected from multiple retailers across various regions. The dataset includes 2115 stores across 25 retailers for 10 months that includes two types of retail formats and covers 16 provinces and 21 cities of China. We study the impacts of the newly introduced online channel on the incumbent offline channel and the overall store performance.The empirical results reveal that the online channel addition mainly has a synergy effect. Specifically,for the overall store, it has a positive effect on the sales and product variety, whereas it has a negative effect on the basket size. Surprisingly, an online channel addition also has a positive effect on the offline sales. Our study adds novel values to multi-channel retailing literature by empirically researching the cannibalization and synergy effect of a new type of online channel, offered by takeaway platforms. It can provide insights for retail enterprises who are interested in introducing O2 O model.
文摘In technology-intensive markets, it is a common strategy for companies to develop long-term multiple generation product lines instead of releasing consecutive single products. Even though this strategy is more profitable than sequentially introducing single product generations, it can also result in inter-product line cannibalization. Cannibalization of multiple-generation product lines is a complex problem that needs to be taken into account at the early product line planning stage in order to sustain long-term profitability. In this paper, we propose an agent-based model that can simulate the potential cannibalization scenarios within a multiple-generation product line. We view a multiple-generation product line (MGPL) as complex adaptive system where each product generation in the MGPL adjusts its sales price over time based on the shifts in the market demand. The proposed model provides insights into how various pricing strategies impact the overall lifecycle profitability of MGPL and can be used to assist companies in developing appropriate dynamic pricing strategies at the early product line planning stages.
基金Fundamental Research Grant Scheme from the Ministry of Higher Education,Malaysia(No.59324)。
文摘Ecdysis is a comm on phe nomenon that happe ns throughout the life phase of the giant freshwater prawn Macrobrachium rosenbergii.It is vital to better understand the correlation between cannibalism and biochemical compound that exists during the moulting process.The objective of the present study was to determine the amino acid profile released by M.rosenbergii during the ecdysis process that promotes cannibalism.To accomplish this,changes in amino acid levels(total amino acid(TAA)and free amino acid(FAA))of tissue muscle,exoskeleton,and sample water of culture medium from the moulting(E-stage)and non-moulting(C-stage)prawns were analysed using highperformanee liquid chromatography(HPLC).Comparison study revealed that among the TAA compounds,proline and sarcosine of tissues from moulting prawn were found at the highest levels.The level of FAA from water that contains moulting prawns(E-stage)was dominated by tryptophan and proline.Significant values obtained in the present study suggested that these amino acid compounds act as a chemical cue to promote cannibalism in M.rosenbergii during ecdysis.The knowledge of compositions and compounds that were released during the moulting process should be helpful for better understanding of the mechanism and chemical cues that play roles on triggering cannibalism,and also for future dietary man ipulati on to improve feeding efficie ncies and feeding man agement,which in directly impacts productivity and profitability.
文摘Cannibalism is an intriguing life history trait, that has been considered primarily in the predator, in predator-prey population models. Recent experimental evidence shows that prey cannibalism can have a significant impact on predator-prey population dyna- mics in natural communities. Motivated by these experimental results, we investigate a ratio-dependent Holling-Tanner model, where cannibalism occurs simultaneously in both the predator and prey species. We show that depending on parameters, whilst prey or predator cannibalism acting alone leads to instability, their joint effect can actually stabilize the unstable interior equilibrium. Furthermore, in the spatially explicit model, we find that depending on parameters, prey and predator cannibalism acting jointly can cause spatial patterns to form, while not so acting individually. We discuss ecologicalconsequences of these findings in light of food chain dynamics, invasive species control and climate change.
文摘Wood frog Lithobates sylvaticus tadpoles develop in temporary wetlands where high population densities can force tadpoles into aggregations that intensify competition and can lead to cannibalism. However, chemical alarm cues released from injured conspecifics could also dissuade cannibalism. The purpose of this study was to test mechanisms that may influence can- nibalistic behaviour. We tested whether the tendency of tadpoles to consume conspecifics would increase with the presence of competition and/or cues of profitable diets. Tadpoles placed in 1L experimental containers were tested for feeding initiation times of multiple diets, including conspecific tissues and conspecific tissues combined with chemical cues from the alternative diets (brine shrimp and comrneal). Tadpoles were tested in the presence and absence of a competitor, and at multiple times over the course of the study. Tadpoles exhibited an altered response to diets over time; however the presence of a competitor reduced re- sponse times to all diets including conspecific tissues. Similarly, the presence of specific diets also reduced the response time of tadpoles to conspecific tissues. These results suggest competition among feeding tadpoles could result in aggressive behaviour leading to indiscriminate predation and cannibalism [Current Zoology 60 (5): 571-580, 2014 ].
文摘Previous observations of cannibalism have been made in the aphid Acyrthosiphon pisum (L.): this article seeks to quantify factors contributing to such be- haviors. We observed and quantified the responses of a number of clones and life stages to varying levels of starvation, in the form of increasingly desiccated Vicafaba L. plants (receiving 50, 25, or 10 mL every second day) or a complete absence of host plant. We found that, while the longest incidences of cannibalism are carried out by juveniles (F = 3.45, P = 0.019, df = 3) and targeted at adults, the starvation treatments had the most significant effect on the prevalence of cannibalism in mature A. pisum (F ---- 2.24, P = 0.025, df = 9). Furthermore, there was no difference between the prevalence or dura- tion of cannibalistic activities within and between different clones (P 〉 0.05 in all cases), though juveniles were more likely to target unrelated aphids (V = 6 112, P = 0.011), and spent more time feeding on aphids from the same culture (V = 6 062, P = 0.018).
基金supported by the National Natural Science Foundation(32172482)Fundamental Research Funds for the Central Universities(KJQN201809)the National Natural Science Foundation(31772185,31972296).
文摘Cannibalism is common in spiders.Wolf spider(Lycosidae)females,which exhibit extensive maternal care,have been reported to cannibalize less when they are carrying egg sacs and juveniles.In a laboratory experiment,we demonstrated that cannibalism of early-instar spiderlings(EIS)by a wolf spider(Pardosa pseudoannulata)mother was almost completely inhibited when she was carrying spiderlings.Compared with virgin and mated-females,mother spiders tolerated more and predated fewer spiderlings,including gregarious pulli and newly dispersed spiderlings(NDS).Cannibalism of EIS by females during their reproductive period exhibited a V-shaped pattern,with a gradual decrease from the egg sac-carrying to pulli-carrying(PC)stage,and a recovery from the PC stage to post-reproductive(PR)stage.Notably,there was 0 cannibalism at the PC stage.PC females exhibited no interest in pulli,while PR females were attracted to and predated pulli and NDS as they did their natural prey,Nilaparvata lugens.Interestingly,PC females captured and released NDS in a foraging assay,although attraction was observed from olfactometer measurements.PC mothers possessed a cuticular volatile profile that was closer to that of pulli and NDS than to that of PR females.Moreover,NDS cuticular extract provoked an electrophysiological response in legs of PC females.Therefore,cuticular compound-mediated chemical communication may be involved in inhibiting cannibalism of EIS by spider mothers,and especially in eliminating cannibalism by PC mothers.Future studies will aim to characterize the specific cuticular compounds and chemoreception mechanism in females,which will facilitate our understanding of intraspecific recognition and cannibalism in spiders.
基金This research was funded by China Agricultural Research System(CARS-40)Beijing Science&Technology Committee Special Project(Z171100002217018).
文摘Colony cages for natural mating have been applied on many layer breeder farms.However,feather pecking and cloacal cannibalism are considered as prominent problems for these systems.This study aimed to investigate the effects on feather pecking and vent pecking behaviors by providing layer breeders with nest boxes(0.90 m L×0.40 m W×0.60 m H)in colony cages for natural mating(4.80 m L×1.20 m W×0.71 m H).Video recording and artificial observation were adopted.The results showed that the usage of nest boxes gradually increased from the beginning of nest boxes providing at the age of 37 weeks to the end of the experiment at the age of 55 weeks.The utilization rates of nest boxes were 36.75%,44.75%and 50.38%at the ages of 41 weeks,47 weeks and 53 weeks,respectively.The hens in the cages without nest boxes showed significantly more frequent gentle feather pecks(both given and received)than hens in the cages with nest boxes at the ages of 41 weeks,47 weeks and 53 weeks.A decreasing trend of gentle feather pecking frequency(both given and received)was found with the increasing age for both the two groups.No significant difference was found in the number of given or received severe feather pecks at the age of 41 weeks.The hens in the cages without nest boxes showed a significantly higher frequency of given and received severe feather pecks than hens in the cages with nest boxes at the ages of 47 weeks and 53 weeks(p<0.05).Both cannibalistic injury occurrence and mortality rate in the cages with nest boxes were significantly lower than those in the cages without nest boxes.In conclusion,providing nest boxes in colony cages for natural mating could decrease abnormal pecking behaviors and improve animal welfare conditions of layer breeders.
基金supported by the NSF of China(11971059)Q.Huang was supported by the NSF of China(11871060)+1 种基金the Venture and Innovation Support Program for Chongqing Overseas Returnees(7820100158),the Fundamental Research Funds for the Central Universities(XDJK2018B031)the faculty startup fund from Southwest University(20710948).
文摘Cannibalism is a life trait occurring in a wide variety of species.To describe the population dynamics of cannibalistic species,we develop a stage-structured population model in which axJults prey on juveniles with a Holling type I functional response.We make a rigorous analysis of the global dynamics in the model.The results of theoretical analysis show that the model has no boundary equilibrium other than the extinction one since juveniles and adults are cooperative(adults reproduce juveniles and juveniles grow into adults).Under certain conditions,the model has multiple interior equilibria and exhibits several types of bistable dynamics,in which different initial densities of juveniles and adults produce different long-term outcomes.
基金This research is supported by the National Research Foundation,Prime Minister's Office,Singapore under its competitive Research Program(CRP Award No.NRF-CRP002-001)and administered by NRF.
文摘While juvenile cannibalism plays an important role in the evolution of organisms in natural populations,it is a serious problem in aquaculture.A number of genetic and environmental factors result in different rates of cannibalism.Whether there is kin recognition in juvenile cannibalism in fish is poorly understood.We studied cannibalism and kinship recognition in juveniles of Asian seabass using molecular parentage analysis with polymorphic microsatellites.In the three mass crosses,under an ordinary feeding scheme without size grading,the rate of juvenile loss due to cannibalism was 1.08% per day.In the group without feeding for 24 h,2.30%±0.43% of offspring per day were lost within 24 h due to cannibalism.We detected that juveniles avoided cannibalizing their siblings when they were not hungry,whereas cannibalism among siblings increased when they were hungry.These data suggest that there is kin discrimination in fish cannibalism.Raising genetically closely related offspring in the same tanks and appropriate levels of feeding may reduce the rate of cannibalism.We hypothesized that the chemical cues for kin discrimination might be secreted by fish skins.To test this hypothesis,we analyzed gene expression profiles in the skins of juveniles under slightly and very hungry conditions using RNA sequencing and bioinformatics analysis.Genes differently expressed under slightly and very hungry conditions were identified.Among them,genes from the trypsin family were significantly downregulated under starved conditions,suggesting that they may play a role in kin discrimination.
文摘The Diary of A Madman (Kuangren r/j/), Lu Xun's first well-known short stoW and the alleged first modem short stow in vernacular Chinese, is famous for its first-person narrative by an intellectual that is suffering from a persecution complex. As acknowledged by Lu Xun himself and argued by most scholars, this short stoW was influenced by Gogol's homonymic short stow, but has developed more profound melancholy and indignation. However, as my paper demonstrates, this perspective neglects the role of Japan as an intermediary in the transculturation of madness. First, Lu Xun's initial encounter with Gogol's Diary of A Madman was through his reading of Futabatei Shimei's translation in the Japanese magazine Ky6mi. Second, the framed narrative and contrasting styles of Lu Xun's short stow, which are not features of Gogol's, might also be due to the inspiration from the Japanese genbun itchi movement in the Meiji period. Third, and most importantly, cannibalism, a major theme in Lu Xun's Diary of A Madman, was arguably shaped by the heated discussion in Japan on national character and cannibalism. My paper will trace the double origin of the depiction of madness and cannibalism in Lu Xun's work and illustrate the importance of the role of Japan in the transculturation of the stow of a madman.