Plants constantly survey the surrounding environment using several sets of photoreceptors. They can sense changes in the quantity （= intensity） and quality （=wavelength） of light and use this information to adjust...Plants constantly survey the surrounding environment using several sets of photoreceptors. They can sense changes in the quantity （= intensity） and quality （=wavelength） of light and use this information to adjust their physiological responses, growth, and developmental patterns. In addition to the classical photoreceptors, such as phytochromes, crypto- chromes, and phototropins, ZEITLUPE （ZTL）, FLAVIN-BINDING, KELCH REPEAT, F-BOX 1 （FKF1）, and LOV KELCH PROTEIN 2 （LKP2） proteins have been recently identified as blue-light photoreceptors that are important for regulation of the circadian clock and photoperiodic flowering. The ZTL/FKF1/LKP2 protein family possesses a unique combination of domains： a blue-light-absorb- ing LOV （Light, Oxygen, or Voltage） domain along with domains involved in protein degradation. Here, we summarize recent advances in our understanding of the function of the Arabidopsis ZTL/FKF1/LKP2 proteins. We summarize the distinct pho- tochemical properties of their LOV domains and discuss the molecular mechanisms by which the ZTL/FKF1/LKP2 proteins reg- ulate the circadian clock and photoperiodic flowering by controlling blue-light-dependent protein degradation.展开更多
The phototropins phot1 and phot2 are plant blue-light receptors that mediate phototropism, chloroplast movements, stomatal opening, leaf expansion, the rapid Inhibition of hypocotyl growth in etiolated seedlings, and ...The phototropins phot1 and phot2 are plant blue-light receptors that mediate phototropism, chloroplast movements, stomatal opening, leaf expansion, the rapid Inhibition of hypocotyl growth in etiolated seedlings, and possibly solar tracking by leaves in those species in which It occurs. The phototroplns are plasma membrane-associated hydrophilic proteins with two chromophore domains （designated LOV1 and LOV2 for their resemblance to domains In other signaling proteins that detect light, oxygen, or voltage） in their Nterminal half and a classic serine/threonlne kinase domain in their C-terminal half. Both chromophore domains bind flavin mononucleotide （FMN） and both undergo light-activated formation of a covalent bond between a nearby cystelne and the C（4a） carbon of the FMN to form the signaling state. LOV2-cystelnyl adduct formation leads to the release downstream of a tightly bound amphlpathlc α-helix, a step required for activation of the klnase function. This cysteinyl adduct then slowly decays over a matter of seconds or minutes to return the photoreceptor chromophore modules to their ground state. Functional LOV2 is required for light-activated phosphorylation and for various blue-light responses mediated by the phototroplns. The function of LOV1 is still unknown, although It may serve to modulate the signal generated by LOV2. The LOV domain Is an ancient chromophore module found In a wide range of otherwise unrelated proteins In fungi and prokaryotes, the latter Including cyanobacterla, eubacterla, and archaea. Further general reviews on the phototropins are those by Celaya and Liscum （2005） and Christie and Briggs （2005）.展开更多
The "Music of the Heart-2011" charity event, jointly sponsored by the Qingdao People’s Association for Friendship with Foreign Countries, the Italian Embassy in China, the Qingdao General Charity Institute ...The "Music of the Heart-2011" charity event, jointly sponsored by the Qingdao People’s Association for Friendship with Foreign Countries, the Italian Embassy in China, the Qingdao General Charity Institute and the Italy Faith Love Hope Fund, was held in the seaside resort from August 26 to 28. The 800,000 RMB raised through Italian classical music concerts and the auctioning of handiworks made by children in the Qingdao Children Welfare Institution was donated to the facility. All the participants were deeply moved by the charity activities and experienced the profound love from a foreign country.展开更多
Aircraft metal components and structures are susceptible to environmental degradation throughout their original design life and in many cases their extended lives.This paper summarizes the results of an experimental p...Aircraft metal components and structures are susceptible to environmental degradation throughout their original design life and in many cases their extended lives.This paper summarizes the results of an experimental program to evaluate the ability of Supersonic Particle Deposition(SPD),also known as cold spray,to extend the limit of validity(LOV)of aircraft structural components and to restore the structural integrity of corroded panels.In this study the potential for the SPD to seal the mechanically fastened joints and for this seal to remain intact even in the presence of multi-site damage(MSD)has been evaluated.By sealing the joint the onset of corrosion damage in the joint can be significantly retarded,possibly even eliminated,thereby dramatically extending the LOV of mechanically fastened joints.The study also shows that SPD can dramatically increase the damage tolerance of badly corroded wing skins.展开更多
An edge coloring of hypergraph H is a function such that holds for any pair of intersecting edges . The minimum number of colors in edge colorings of H is called the chromatic index of H and is ...An edge coloring of hypergraph H is a function such that holds for any pair of intersecting edges . The minimum number of colors in edge colorings of H is called the chromatic index of H and is denoted by . Erdös, Faber and Lovász proposed a famous conjecture that holds for any loopless linear hypergraph H with n vertices. In this paper, we show that is true for gap-restricted hypergraphs. Our result extends a result of Alesandroni in 2021.展开更多
文摘Plants constantly survey the surrounding environment using several sets of photoreceptors. They can sense changes in the quantity （= intensity） and quality （=wavelength） of light and use this information to adjust their physiological responses, growth, and developmental patterns. In addition to the classical photoreceptors, such as phytochromes, crypto- chromes, and phototropins, ZEITLUPE （ZTL）, FLAVIN-BINDING, KELCH REPEAT, F-BOX 1 （FKF1）, and LOV KELCH PROTEIN 2 （LKP2） proteins have been recently identified as blue-light photoreceptors that are important for regulation of the circadian clock and photoperiodic flowering. The ZTL/FKF1/LKP2 protein family possesses a unique combination of domains： a blue-light-absorb- ing LOV （Light, Oxygen, or Voltage） domain along with domains involved in protein degradation. Here, we summarize recent advances in our understanding of the function of the Arabidopsis ZTL/FKF1/LKP2 proteins. We summarize the distinct pho- tochemical properties of their LOV domains and discuss the molecular mechanisms by which the ZTL/FKF1/LKP2 proteins reg- ulate the circadian clock and photoperiodic flowering by controlling blue-light-dependent protein degradation.
基金Supported by the National Science Foundation, USA, grants MCB 0091384 and 0444504 to WRB, MCB0444390 to RAB, and by the UK Biotechnology and Biological Sciences Research Council, grant BB/C000366/1 to JMC. Publication of this paper is supported by the National Natural Science Foundation of China （30624808） and Science Publication Foundation of the Chinese Academy of Sciences.
文摘The phototropins phot1 and phot2 are plant blue-light receptors that mediate phototropism, chloroplast movements, stomatal opening, leaf expansion, the rapid Inhibition of hypocotyl growth in etiolated seedlings, and possibly solar tracking by leaves in those species in which It occurs. The phototroplns are plasma membrane-associated hydrophilic proteins with two chromophore domains （designated LOV1 and LOV2 for their resemblance to domains In other signaling proteins that detect light, oxygen, or voltage） in their Nterminal half and a classic serine/threonlne kinase domain in their C-terminal half. Both chromophore domains bind flavin mononucleotide （FMN） and both undergo light-activated formation of a covalent bond between a nearby cystelne and the C（4a） carbon of the FMN to form the signaling state. LOV2-cystelnyl adduct formation leads to the release downstream of a tightly bound amphlpathlc α-helix, a step required for activation of the klnase function. This cysteinyl adduct then slowly decays over a matter of seconds or minutes to return the photoreceptor chromophore modules to their ground state. Functional LOV2 is required for light-activated phosphorylation and for various blue-light responses mediated by the phototroplns. The function of LOV1 is still unknown, although It may serve to modulate the signal generated by LOV2. The LOV domain Is an ancient chromophore module found In a wide range of otherwise unrelated proteins In fungi and prokaryotes, the latter Including cyanobacterla, eubacterla, and archaea. Further general reviews on the phototropins are those by Celaya and Liscum （2005） and Christie and Briggs （2005）.
文摘The "Music of the Heart-2011" charity event, jointly sponsored by the Qingdao People’s Association for Friendship with Foreign Countries, the Italian Embassy in China, the Qingdao General Charity Institute and the Italy Faith Love Hope Fund, was held in the seaside resort from August 26 to 28. The 800,000 RMB raised through Italian classical music concerts and the auctioning of handiworks made by children in the Qingdao Children Welfare Institution was donated to the facility. All the participants were deeply moved by the charity activities and experienced the profound love from a foreign country.
文摘Aircraft metal components and structures are susceptible to environmental degradation throughout their original design life and in many cases their extended lives.This paper summarizes the results of an experimental program to evaluate the ability of Supersonic Particle Deposition(SPD),also known as cold spray,to extend the limit of validity(LOV)of aircraft structural components and to restore the structural integrity of corroded panels.In this study the potential for the SPD to seal the mechanically fastened joints and for this seal to remain intact even in the presence of multi-site damage(MSD)has been evaluated.By sealing the joint the onset of corrosion damage in the joint can be significantly retarded,possibly even eliminated,thereby dramatically extending the LOV of mechanically fastened joints.The study also shows that SPD can dramatically increase the damage tolerance of badly corroded wing skins.
文摘An edge coloring of hypergraph H is a function such that holds for any pair of intersecting edges . The minimum number of colors in edge colorings of H is called the chromatic index of H and is denoted by . Erdös, Faber and Lovász proposed a famous conjecture that holds for any loopless linear hypergraph H with n vertices. In this paper, we show that is true for gap-restricted hypergraphs. Our result extends a result of Alesandroni in 2021.
