1,156 research outputs found
Product Quality Selection and Firm Survival. Evidence from the British Automobile Industry, 1895-1970.
This paper proposes an additional determininant of firm survival. Based on a detailed examination of firm survival in the British automobile industry between 1895 and 1970, we conclude that firm’s selection of submarket-defined by quality level-influenced survival. In contrast to findings for the US automobile industry, there is no evidence of first-mover advantage in the market as a whole. However, we do find evidence of first-mover advantage after conditioning on submarket choice.firm survival, product differentiation, submarket, product quality
Temperature compensation via cooperative stability in protein degradation
Temperature compensation is a notable property of circadian oscillators that
indicates the insensitivity of the oscillator system's period to temperature
changes; the underlying mechanism, however, is still unclear. We investigated
the influence of protein dimerization and cooperative stability in protein
degradation on the temperature compensation ability of two oscillators. Here,
cooperative stability means that high-order oligomers are more stable than
their monomeric counterparts. The period of an oscillator is affected by the
parameters of the dynamic system, which in turn are influenced by temperature.
We adopted the Repressilator and the Atkinson oscillator to analyze the
temperature sensitivity of their periods. Phase sensitivity analysis was
employed to evaluate the period variations of different models induced by
perturbations to the parameters. Furthermore, we used experimental data
provided by other studies to determine the reasonable range of parameter
temperature sensitivity. We then applied the linear programming method to the
oscillatory systems to analyze the effects of protein dimerization and
cooperative stability on the temperature sensitivity of their periods, which
reflects the ability of temperature compensation in circadian rhythms. Our
study explains the temperature compensation mechanism for circadian clocks.
Compared with the no-dimer mathematical model and linear model for protein
degradation, our theoretical results show that the nonlinear protein
degradation caused by cooperative stability is more beneficial for realizing
temperature compensation of the circadian clock.Comment: 27 pages, 5 figure
Stomata at the crossroad of molecular interaction between biotic and abiotic stress responses in plants
Increasing global food production is threatened by harsh environmental conditions along with biotic stresses, requiring massive new research into integrated stress resistance in plants. Stomata play a pivotal role in response to many biotic and abiotic stresses, but their orchestrated interactions at the molecular, physiological, and biochemical levels were less investigated. Here, we reviewed the influence of drought, pathogen, and insect herbivory on stomata to provide a comprehensive overview in the context of stomatal regulation. We also summarized the molecular mechanisms of stomatal response triggered by these stresses. To further investigate the effect of stomata–herbivore interaction at a transcriptional level, integrated transcriptome studies from different plant species attacked by different pests revealed evidence of the crosstalk between abiotic and biotic stress. Comprehensive understanding of the involvement of stomata in some plant– herbivore interactions may be an essential step towards herbivores’ manipulation of plants, which provides insights for the development of integrated pest management strategies. Moreover, we proposed that stomata can function as important modulators of plant response to stress combination, representing an exciting frontier of plant science with a broad and precise view of plant biotic interactions
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