Color is one of the phenotypic markers mostly used to study soybean (Glycine max L. Merr.) in the study of genetic, molecular and biochemical processes, due to their easy recognizability. The genetic control of severa...Color is one of the phenotypic markers mostly used to study soybean (Glycine max L. Merr.) in the study of genetic, molecular and biochemical processes, due to their easy recognizability. The genetic control of several soybean natural variants has not been studied. The standard phenotype of R gene is black hilum on black seed. The genetic type T16 is the only occurrence with brown hilum on black seed coat and its genetic control was not described until now. The aim of this study is to understand the genetic control of seed coat and hilum color in the genetic types T16 and in the natural variants of Bragg, BR6 and BR13. T16 was combinined with Bragg P and BR13P (black seed color) and BR6M (brown seed color) and T236 (r-m). It was found that the genetic control of the brown hilum trait in black seed coat of the T16 genotype was controlled by two loci segregating independently and controlling the expression of the color of the hilum and the seed coat color. The expression of the brown hilum trait in black seed coat is dependent on locus T_, which controls pubescence color;therefore it occurs only in genotypes with tawny brown pubescence (T_), which caracterizes the pleiotropic effect of this locus on the trait hilum brown trait in black seed coat. The color of the hilum and the seed coat color belong to the same allelic sequence. No maternal effect was found in the expression of hilum brown trait in black seed coat.展开更多
The world of natural materials and structures provides an abundance of applications in which mechanics is a critical issue for our understanding of functional material properties. In particular, the mechanical propert...The world of natural materials and structures provides an abundance of applications in which mechanics is a critical issue for our understanding of functional material properties. In particular, the mechanical properties of biological materials and structures play an important role in virtually all physiological processes and at all scales, from the molecular and nanoscale to the macroscale, linking research fields as diverse as genetics to structural mechanics in an approach referred to as materiomics. Example cases that illustrate the importance of mechanics in biology include mechanical support provided by materials like bone, the facilitation of locomotion capabilities by muscle and tendon, or the protection against environmental impact by materials as the skin or armors. In this article we review recent progress and case studies, relevant for a variety of applications that range from medicine to civil engineering. We demonstrate the importance of fundamental mechanistic insight at multiple time- and length-scales to arrive at a systematic understanding of materials and structures in biology, in the context of both physiological and disease states and for the development of de novo biomaterials. Three particularly intriguing issues that will be discussed here include: First, the capacity of biological systems to turn weakness to strength through the utilization of multiple structural levels within the universality-diversity paradigm. Second, material breakdown in extreme and disease conditions. And third, we review an example where the hierarchical design paradigm found in natural protein materials has been applied in the development of a novel hiomaterial based on amyloid protein.展开更多
In the inspiring extract highlighted in this paper,Saussure observes how the relation between the elements of the sign change and evolve over time.In his Cours,he also details the elements of the linguistic sign and t...In the inspiring extract highlighted in this paper,Saussure observes how the relation between the elements of the sign change and evolve over time.In his Cours,he also details the elements of the linguistic sign and the principles governing them,defining language as a system of signs.Despite the natural resistance to changes in language in order to enable it to continually fulfill its function,that is,despite the necessary immutability of linguistic signs,they change over time,by being in constant contact with the communities of speakers,to whom language actually belongs.This may seem paradoxical because language is composed of arbitrary relations between signified and signifier that seek to represent concepts.Saussure refers to a principle of change in language linked to a principle of continuity.The present study focuses on the semiotic and communicational aspects of the development of linguistic systems in time,understood from a systemic perspective.It is sought to evince how signs perpetuate themselves and evolve through their constant interaction with real communities of language users.This approach can offer new insights about the continuity of linguistic systems as systems of signs that present immutable and mutable characters,and whose evolution can be understood based on open systems parameters,such as permanence,autonomy and sensitivity to flows of information,as studied by current theories and authors,showing that,to preserve its semiological life (CGL,1959,p.76),a living language must continuously reflect the purposes of its users.展开更多
Purpose–The purpose of the current investigation is to design a robust and reliable computational framework to effectively identify the nonlinear behavior of shape memory alloy(SMA)actuators,as one of the most applic...Purpose–The purpose of the current investigation is to design a robust and reliable computational framework to effectively identify the nonlinear behavior of shape memory alloy(SMA)actuators,as one of the most applicable types of actuators in engineering and industry.The motivation of proposing such an intelligent paradigm emanates in the pursuit of fulfilling the necessity of devising a simple yet effective identification system capable of modeling the hysteric dynamical respond of SMA actuators.Design/methodology/approach–To address the requirements of designing a pragmatic identification system,the authors integrate a set of fast yet reliable intelligent methodologies and provide a predictive tool capable of realizing the nonlinear hysteric behavior of SMA actuators in a computationally efficient fashion.First,the authors utilize the governing equations to design a gray box Hammerstein-Wiener identifier model.At the next step,they adopt a computationally efficient metaheuristic algorithm to elicit the optimum operating parameters of the gray box identifier.Findings–Applying the proposed hybrid identifier framework allows the authors to find out its advantages in modeling the behavior of SMA actuator.Through different experiments,the authors conclude that the proposed identifier can be used for identification of highly nonlinear dynamic behavior of SMA actuators.Furthermore,by extending the conclusions and expounding the obtained results,one can easily infer that such a hybrid method may be conveniently applied to model other engineering phenomena that possess dynamic nonlinear reactions.Based on the exerted experiments and implementing the method,the authors come to the conclusion that integrating the power of metaheuristic exploration/exploitation with gray box identifier results a predictive paradigm that much more computationally efficient as compared with black box identifiers such as neural networks.Additionally,the derived gray box method has a higher degree of preference over the black box identifiers,as it allows a manipulated expert to extract the knowledge of the system at hand.Originality/value–The originality of the research paper is twofold.From the practical(engineering)point of view,the authors built a prototype biased-spring SMA actuator and carried out several experiments to ascertain and validate the parameters of the model.From the computational point of view,the authors seek for designing a novel identifier that overcomes the main flaws associated with the performance of black-box identifiers that are the lack of a mean for extracting the governing knowledge of the system at hand,and high computational expense pertinent to the structure of black-box identifiers.展开更多
文摘Color is one of the phenotypic markers mostly used to study soybean (Glycine max L. Merr.) in the study of genetic, molecular and biochemical processes, due to their easy recognizability. The genetic control of several soybean natural variants has not been studied. The standard phenotype of R gene is black hilum on black seed. The genetic type T16 is the only occurrence with brown hilum on black seed coat and its genetic control was not described until now. The aim of this study is to understand the genetic control of seed coat and hilum color in the genetic types T16 and in the natural variants of Bragg, BR6 and BR13. T16 was combinined with Bragg P and BR13P (black seed color) and BR6M (brown seed color) and T236 (r-m). It was found that the genetic control of the brown hilum trait in black seed coat of the T16 genotype was controlled by two loci segregating independently and controlling the expression of the color of the hilum and the seed coat color. The expression of the brown hilum trait in black seed coat is dependent on locus T_, which controls pubescence color;therefore it occurs only in genotypes with tawny brown pubescence (T_), which caracterizes the pleiotropic effect of this locus on the trait hilum brown trait in black seed coat. The color of the hilum and the seed coat color belong to the same allelic sequence. No maternal effect was found in the expression of hilum brown trait in black seed coat.
基金Project supported by NSF, ARO,AFOSR and ONR.Additional support from DARPA and the MITEI
文摘The world of natural materials and structures provides an abundance of applications in which mechanics is a critical issue for our understanding of functional material properties. In particular, the mechanical properties of biological materials and structures play an important role in virtually all physiological processes and at all scales, from the molecular and nanoscale to the macroscale, linking research fields as diverse as genetics to structural mechanics in an approach referred to as materiomics. Example cases that illustrate the importance of mechanics in biology include mechanical support provided by materials like bone, the facilitation of locomotion capabilities by muscle and tendon, or the protection against environmental impact by materials as the skin or armors. In this article we review recent progress and case studies, relevant for a variety of applications that range from medicine to civil engineering. We demonstrate the importance of fundamental mechanistic insight at multiple time- and length-scales to arrive at a systematic understanding of materials and structures in biology, in the context of both physiological and disease states and for the development of de novo biomaterials. Three particularly intriguing issues that will be discussed here include: First, the capacity of biological systems to turn weakness to strength through the utilization of multiple structural levels within the universality-diversity paradigm. Second, material breakdown in extreme and disease conditions. And third, we review an example where the hierarchical design paradigm found in natural protein materials has been applied in the development of a novel hiomaterial based on amyloid protein.
文摘In the inspiring extract highlighted in this paper,Saussure observes how the relation between the elements of the sign change and evolve over time.In his Cours,he also details the elements of the linguistic sign and the principles governing them,defining language as a system of signs.Despite the natural resistance to changes in language in order to enable it to continually fulfill its function,that is,despite the necessary immutability of linguistic signs,they change over time,by being in constant contact with the communities of speakers,to whom language actually belongs.This may seem paradoxical because language is composed of arbitrary relations between signified and signifier that seek to represent concepts.Saussure refers to a principle of change in language linked to a principle of continuity.The present study focuses on the semiotic and communicational aspects of the development of linguistic systems in time,understood from a systemic perspective.It is sought to evince how signs perpetuate themselves and evolve through their constant interaction with real communities of language users.This approach can offer new insights about the continuity of linguistic systems as systems of signs that present immutable and mutable characters,and whose evolution can be understood based on open systems parameters,such as permanence,autonomy and sensitivity to flows of information,as studied by current theories and authors,showing that,to preserve its semiological life (CGL,1959,p.76),a living language must continuously reflect the purposes of its users.
文摘Purpose–The purpose of the current investigation is to design a robust and reliable computational framework to effectively identify the nonlinear behavior of shape memory alloy(SMA)actuators,as one of the most applicable types of actuators in engineering and industry.The motivation of proposing such an intelligent paradigm emanates in the pursuit of fulfilling the necessity of devising a simple yet effective identification system capable of modeling the hysteric dynamical respond of SMA actuators.Design/methodology/approach–To address the requirements of designing a pragmatic identification system,the authors integrate a set of fast yet reliable intelligent methodologies and provide a predictive tool capable of realizing the nonlinear hysteric behavior of SMA actuators in a computationally efficient fashion.First,the authors utilize the governing equations to design a gray box Hammerstein-Wiener identifier model.At the next step,they adopt a computationally efficient metaheuristic algorithm to elicit the optimum operating parameters of the gray box identifier.Findings–Applying the proposed hybrid identifier framework allows the authors to find out its advantages in modeling the behavior of SMA actuator.Through different experiments,the authors conclude that the proposed identifier can be used for identification of highly nonlinear dynamic behavior of SMA actuators.Furthermore,by extending the conclusions and expounding the obtained results,one can easily infer that such a hybrid method may be conveniently applied to model other engineering phenomena that possess dynamic nonlinear reactions.Based on the exerted experiments and implementing the method,the authors come to the conclusion that integrating the power of metaheuristic exploration/exploitation with gray box identifier results a predictive paradigm that much more computationally efficient as compared with black box identifiers such as neural networks.Additionally,the derived gray box method has a higher degree of preference over the black box identifiers,as it allows a manipulated expert to extract the knowledge of the system at hand.Originality/value–The originality of the research paper is twofold.From the practical(engineering)point of view,the authors built a prototype biased-spring SMA actuator and carried out several experiments to ascertain and validate the parameters of the model.From the computational point of view,the authors seek for designing a novel identifier that overcomes the main flaws associated with the performance of black-box identifiers that are the lack of a mean for extracting the governing knowledge of the system at hand,and high computational expense pertinent to the structure of black-box identifiers.