Drought and flooding are environmental extremes and major threats to crop production. Water uptake is achieved by plant roots which have to explore new soil spaces to alleviate water deficit during drought or to cope with water excess during flooding. Adaptation of the root system architecture helps plants cope with such extreme conditions and is crucial for plant health and survival. While for dicot plants the well studied model plant Arabidopsis thaliana has provided insight into the genetic and molecular regulation of the root system, less information is available for monocot species, which include the agronomically important cereal crops. Rice (Oryza sativa L.) is a semi-aquatic monocot plant that develops strong tolerance to flooding. Flooding tolerance of rice is closely linked to its adaptive root system. The functional root system of rice is mainly composed of crown roots and is shifted to nodal adventitious roots during flooding which allows rice to maintain oxygen supply to the roots and to survive longer periods of partial submergence as compared with other crops. Likewise, a number of drought-tolerance traits of rice are the result of an altered root system architecture. Hence, the structure of the root system adapts to, both, flooding and drought. Understanding the regulatory mechanisms that control root system adaptation to extreme environments is a key task for scientists to accelerate the breeding efforts for stress-tolerant crops. This review summarizes recently identified genes and molecular mechanisms that regulate root system architecture in rice in response to drought and flooding.
Over ten years ago Buchwald (1995a) discussed Jean Perrin and J. J. Thomson’s attempt to replicate Hertz’s cathode ray experiment. He concluded that both failed to achieve their purpose. Mattingly (2001) thought that Buchwald made a mistake in focusing on Hertz’s experimental instruments and suggested that we should focus instead on Hertz’s experimental goal. He concluded that Thomson did in fact replicate Hertz’s experiment, while Perrin did not. I propose we should tackle the general problem of an experiment’s replication by considering ends and means together. So the aim of the present paper can be laid out by the following points. First, I shall build a theoretical scheme to analyze the structure of experimentation in virtue of the means-end relation. Second, I shall propose a general theory, based on the notion of the degree of replication. Third, I shall claim that Thomson did replicate Hertz’s experiment to a higher degree than did Perrin by means of an analysis different from Mattingly’s.
This paper offers a novel explanation for the lower urbanization rate and great urban-rural inequality in China. Our study reveals that, heavy-industry-oriented development strategy will result in lower urbanization rate and higher urban-rural inequality. The greater the degree of heavy-industryoriented development strategy is, the lower the urbanization rate is, and the higher the urban-rural inequality is. From a dynamic perspective, heavy-industryoriented development strategy reduces the capital accumulation rate, which results in a slower progress of urbanization and a highly persistent urban-rural inequality. The higher the degree of heavy-industry-oriented development strategy, the slower the progress of urbanization, and the longer the urban-rural inequality will last. This mechanism can potentially explain the lower urbanization rate and higher urban-rural inequality in China under a unified framework.
The brightness or color appearance of a region may be altered by the presence of a pattern surrounding it in the visual field. The Munker–White effect (grating surround) and brightness or color induction from concentric annuli ('bull's-eye' surround) are two examples. We examined whether these two phenomena share similar properties. In the asymmetric matching experiment, the task of an observer was to adjust the appearance of a matching patch to match the appearance of a test patch embedded in one of the two types (square wave grating or concentric annuli) of inducing surrounds (inducers). The inducer modulated in one of three color directions (isochromatic: ±(L + M + S) and isoluminance: ±(L – M) or ±S). Each inducer type and color direction had two opposing phases and four contrast levels. The results show that the induced appearance shift increases as a power function of the inducer contrast, regardless of the spatial configuration of the inducer. Further analysis showed that a sensitivity modulation model of lateral interaction could explain both induction effects.
Much has happened in the field of contemporary epistemology since Quine’s “Epistemology Naturalized” was published in 1969. Even before Ronald Giere published his article “Philosophy of Science Naturalized,” naturalized philosophy of science had been influenced by the so-called historical approach. Kuhm, Lakatos, Feyerabend and Laudan all contributed importantly to this trend. In this light it has emerged, without a doubt, that philosophy of science is closely related to epistemology. This volume explores some of the relevant relations and will be of interest to epistemologists and philosophers of science.