Intracellular signals mediated by the family of receptor tyrosine kinases play pivotal roles in morphogenesis, cell fate determination and pathogenesis. Precise control of signal amplitude and duration is critical for...Intracellular signals mediated by the family of receptor tyrosine kinases play pivotal roles in morphogenesis, cell fate determination and pathogenesis. Precise control of signal amplitude and duration is critical for the fidelity and robustness of these processes. Activation of receptor tyrosine kinases by their cognate growth factors not only leads to propagation of the signal through various biochemical cascades, but also sets in motion multiple attenuation mechanisms that ulti- mately terminate the active state. Early attenuators pre-exist prior to receptor activation and they act to limit signal propagation. Subsequently, late attenuators, such as Lrig and Sprouty, are transcriptionally induced and further act to dampen the signal. Central to the process of signaling attenuation is the role of the E3 ubiquitin ligase c-Cbl. While Cbl- mediated processes of receptor ubiquitylation and endocytosis are relatively well understood, the links of Cbl to other negative regulators are just now beginning to be appreciated. Here we review some emerging interfaces between Cbl and the transcriptionally induced negative regulators Lrig and Sprouty.展开更多
The Old Man and the Sea is Hemingway＇s last important work which is regarded by critics as the summary of his life and his philosophic views on life. The paper attempts to approach the story with the view of existent...The Old Man and the Sea is Hemingway＇s last important work which is regarded by critics as the summary of his life and his philosophic views on life. The paper attempts to approach the story with the view of existentialism, which flourished at the time when Hemingway began to create this novella. In light of the existentialist views on the relations between being-in-itself and being-for-itself, and existence and essence, the author tends to analyze the interactions of the characters of the story with themselves through the choices they made, which is to be of significance for those who strive to understand Hemingway＇s work and who try to comprehend human beings and themselves.展开更多
The exploration of Mars, alike of other planets, would be oriented on a so called on-line tracking. At this approach the development of structural indicators can be followed at time using geological receptors. The pri...The exploration of Mars, alike of other planets, would be oriented on a so called on-line tracking. At this approach the development of structural indicators can be followed at time using geological receptors. The principle on what stays this exploration stems from the fact, that a planet is an object, where interactions among its elements are to some extent organized. It means that it goes about an object with a hidden system of control aiming to augment its level of existence and that it is not a ＂stack of stones＂. In advance it is necessary to establish some ways-out for the on-line tracking. The first way-out is the fact, that this is an object been monitored, it means a system of organized elements, which has its proper existence and its strategies for a cultivation of this existence. These elements are primarily atoms and for a monitoring of their activities it is possible to use their complexes, e.g. crystals and of course occasionally higher structures, too. Another way-out is the fact, that elements have their proper satisfaction and successfulness and that on basis of those quantities stays the existence of the overall object. These quantities are for new observable mainly on higher structures.展开更多
We study the blow-up and/or global existence of the following p-Laplacian evolution equation with variable source power where Ω is either a bounded domain or the whole space RN and q（x） is a positive and continuous...We study the blow-up and/or global existence of the following p-Laplacian evolution equation with variable source power where Ω is either a bounded domain or the whole space RN and q（x） is a positive and continuous function defined in with 0 〈 q- infq（x） = q（x） 〈 ∞supq（x） = q＋ 〈 ∞. It is demonstrated that the equation with variable source power has much richer dynamics with interesting phenomena which depends on the interplay of q（x） and the structure of spatial domain Ω, compared with the case of constant source power. For the case that is a bounded domain, the exponent p - 1 plays a crucial role. If q＋ 〉 p - 1, there exist blow-up solutions, while if q＋ p - 1, all the solutions are global. If q-〉 p - 1, there exist global solutions, while for given q- 〈 p - 1 〈 q＋, there exist some function q（x） and such that all nontrivial solutions will blow up, which is called the Fujita phenomenon. For the case Ω = RN the Fujita phenomenon occurs if 1 q＋ q＋ ≤p--1＋p/N, while if q_ 〉 p -- 1 ＋p/N there exist global solutions.展开更多
文摘Intracellular signals mediated by the family of receptor tyrosine kinases play pivotal roles in morphogenesis, cell fate determination and pathogenesis. Precise control of signal amplitude and duration is critical for the fidelity and robustness of these processes. Activation of receptor tyrosine kinases by their cognate growth factors not only leads to propagation of the signal through various biochemical cascades, but also sets in motion multiple attenuation mechanisms that ulti- mately terminate the active state. Early attenuators pre-exist prior to receptor activation and they act to limit signal propagation. Subsequently, late attenuators, such as Lrig and Sprouty, are transcriptionally induced and further act to dampen the signal. Central to the process of signaling attenuation is the role of the E3 ubiquitin ligase c-Cbl. While Cbl- mediated processes of receptor ubiquitylation and endocytosis are relatively well understood, the links of Cbl to other negative regulators are just now beginning to be appreciated. Here we review some emerging interfaces between Cbl and the transcriptionally induced negative regulators Lrig and Sprouty.
文摘The Old Man and the Sea is Hemingway＇s last important work which is regarded by critics as the summary of his life and his philosophic views on life. The paper attempts to approach the story with the view of existentialism, which flourished at the time when Hemingway began to create this novella. In light of the existentialist views on the relations between being-in-itself and being-for-itself, and existence and essence, the author tends to analyze the interactions of the characters of the story with themselves through the choices they made, which is to be of significance for those who strive to understand Hemingway＇s work and who try to comprehend human beings and themselves.
文摘The exploration of Mars, alike of other planets, would be oriented on a so called on-line tracking. At this approach the development of structural indicators can be followed at time using geological receptors. The principle on what stays this exploration stems from the fact, that a planet is an object, where interactions among its elements are to some extent organized. It means that it goes about an object with a hidden system of control aiming to augment its level of existence and that it is not a ＂stack of stones＂. In advance it is necessary to establish some ways-out for the on-line tracking. The first way-out is the fact, that this is an object been monitored, it means a system of organized elements, which has its proper existence and its strategies for a cultivation of this existence. These elements are primarily atoms and for a monitoring of their activities it is possible to use their complexes, e.g. crystals and of course occasionally higher structures, too. Another way-out is the fact, that elements have their proper satisfaction and successfulness and that on basis of those quantities stays the existence of the overall object. These quantities are for new observable mainly on higher structures.
基金supported by Shanxi Bairen Plan of China and Ng-Jhit-Cheong Foundation
文摘We study the blow-up and/or global existence of the following p-Laplacian evolution equation with variable source power where Ω is either a bounded domain or the whole space RN and q（x） is a positive and continuous function defined in with 0 〈 q- infq（x） = q（x） 〈 ∞supq（x） = q＋ 〈 ∞. It is demonstrated that the equation with variable source power has much richer dynamics with interesting phenomena which depends on the interplay of q（x） and the structure of spatial domain Ω, compared with the case of constant source power. For the case that is a bounded domain, the exponent p - 1 plays a crucial role. If q＋ 〉 p - 1, there exist blow-up solutions, while if q＋ p - 1, all the solutions are global. If q-〉 p - 1, there exist global solutions, while for given q- 〈 p - 1 〈 q＋, there exist some function q（x） and such that all nontrivial solutions will blow up, which is called the Fujita phenomenon. For the case Ω = RN the Fujita phenomenon occurs if 1 q＋ q＋ ≤p--1＋p/N, while if q_ 〉 p -- 1 ＋p/N there exist global solutions.
