Ca Lu - Academia.edu (original) (raw)

Papers by Ca Lu

Fiber Lasers V: Technology, Systems, and Applications, 2008

A new technique for mitigating stimulated Brillouin scattering (SBS) effects in narrow-linewidth ... more A new technique for mitigating stimulated Brillouin scattering (SBS) effects in narrow-linewidth Yb-doped fiber amplifiers is demonstrated with a model that reduces to solving an 8×8 system of coupled nonlinear equations with the gain, SBS, and four-wave mixing (FMW) incorporated into the model. This technique uses two seed signals, or 'two-tones', with each tone reaching its SBS threshold almost independently

SPIE Proceedings, 2014

We present an experimental study on beam combining techniques with multiple vertical external cav... more We present an experimental study on beam combining techniques with multiple vertical external cavity surface emitting lasers (VECSELs) using volume Bragg gratings (VBGs). The specially designed holographic gratings introduce frequency specific feedback for the near infrared wavelength VECSELs to achieve both spectral linewidth narrowing and beam combination effects. For coherent addition, we obtained >3W output power with 8% slope efficiency in a coherent power scaling cavity scheme. In the multiplexed VBGs (MVBGs) wavelength beam combining compound cavity scheme, we measured >6W combined output with nearly 100% combining efficiency. Both beam combining/power scaling schemes produced spectrally narrowed and near diffraction limited outputs.

2011 IEEE/WIC/ACM International Conferences on Web Intelligence and Intelligent Agent Technology, 2011

data points usually pose an approach to al data by efficiently ture, called Geo-tree, d then deve... more data points usually pose an approach to al data by efficiently ture, called Geo-tree, d then develop two geographic data and representation. The oach is very efficient and HAC, and the s. lization; geographic N days are suitable to ems. Compared to ng geographic data information about sers browse (zoom e further messages. the easiest ways to however, it causes

RNA Biology, 2012

largely on the leaf. After detection of the optimal photoperiod, a systemic floral regulator or f... more largely on the leaf. After detection of the optimal photoperiod, a systemic floral regulator or florigen, is synthesized in the leaf. This graft-transmittable signaling molecule then traffics long distance through the phloem to the shoot apices and stimulates floral initiation. 5,6 In an Arabidopsis inducible-promoter system, the RNA of FLOWERING LOCUS T (FT) was suggested to function as a component of florigen. 7 However, the paper was later retracted 8 and subsequent experiments identified that FT protein rather than RNA may function as this long-sought-after florigen. 9,10 Arabidopsis FT encodes an RAF kinase inhibitor-like protein. 11,12 The accumulation of FT RNA depends on light and is positively regulated by CONSTANS (CO), a zinc-finger transcription factor involved in the photoperiodic pathway. 13,14 Both FT and CO are mainly expressed in vascular tissues. 15 When FT or CO was ectopically expressed in the apex, only FT triggered floral initiation, which suggests that FT may act as a systemic floral regulator. 16,17 The identification of the FT-interacting protein FD, a bZIP transcription factor, showed that FD is required for the function of FT. 18,19 Given that FD is specifically expressed in the apex, but FT is predominantly expressed in vascular tissues, FT protein, FT RNA or even

CLEO:2011 - Laser Applications to Photonic Applications, 2011

Abstract Single-frequency coherent beam combination (CBC) of 16 fiber lasers with kW class output... more Abstract Single-frequency coherent beam combination (CBC) of 16 fiber lasers with kW class output power is presented. In addition, kW scale CBC of three Photonic Crystal Fiber (PCF) amplifiers in a filled aperture configuration is reported.

Thin Solid Films, 2000

ABSTRACT

The Plant Cell, 2007

Sugars repress α-amylase expression in germinating embryos and cell cultures of rice (Oryza sativ... more Sugars repress α-amylase expression in germinating embryos and cell cultures of rice (Oryza sativa) through a sugar response complex (SRC) in α-amylase gene promoters and its interacting transcription factor MYBS1. The Snf1 protein kinase is required for the derepression of glucose-repressible genes in yeast. In this study, we explored the role of the yeast Snf1 ortholog in rice, SnRK1, in sugar signaling and plant growth. Rice embryo transient expression assays indicated that SnRK1A and SnRK1B act upstream and relieve glucose repression of MYBS1 and αAmy3 SRC promoters. Both SnRK1s contain N-terminal kinase domains serving as activators and C-terminal regulatory domains as dominant negative regulators of SRC. The accumulation and activity of SnRK1A was regulated by sugars posttranscriptionally, and SnRK1A relieved glucose repression specifically through the TA box in SRC. A transgenic RNA interference approach indicated that SnRK1A is also necessary for the activation of MYBS1 and ...

The Plant Cell, 2002

The expression of ␣-amylase genes in cereals is induced by both gibberellin (GA) and sugar starva... more The expression of ␣-amylase genes in cereals is induced by both gibberellin (GA) and sugar starvation. All ␣-amylase genes isolated from cereals contain a TATCCA element or its variants at positions ‫ف‬ 90 to 150 bp upstream of the transcription start sites. The TATCCA element was shown previously to be an important component of the GA response complex and the sugar response complex of ␣-amylase gene promoters. In the present study, three cDNA clones encoding novel MYB proteins with single DNA binding domains were isolated from a rice suspension cell cDNA library and designated OsMYBS1 , OsMYBS2 , and OsMYBS3. Gel mobility shift experiments with OsMYBSs showed that they bind specifically to the TATCCA element in vitro. Yeast one-hybrid experiments demonstrated that OsMYBS1 and OsMYBS2 bind to the TATCCA element and transactivate a promoter containing the TATCCA element in vivo. Transient expression assays with barley half-seeds showed that OsMYBS1 and OsMYBS2 transactivate a promoter containing the TATCCA element when sugar is provided, whereas OsMYBS3 represses transcription of the same promoter under sugar starvation. Transient expression assays also showed that these three OsMYBSs cooperate with a GA-regulated transcription factor, HvMYBGa, in the transactivation of a low-pI barley ␣-amylase gene promoter in the absence of GA. Two-hybrid experiments with barley half-seeds showed that OsMYBS1 is able to form a homodimer. The present study demonstrates that differential DNA binding affinity, promoter transactivation ability, dimerization, and interactions with other protein factors determine the biological function of OsMYBSs. This study also suggests that common transcription factors are involved in the sugar and hormonal regulation of ␣-amylase gene expression in cereals.

Science Signaling, 2009

The protein kinase CIPK15 integrates the response to hypoxia with sugar signaling to allow submer... more The protein kinase CIPK15 integrates the response to hypoxia with sugar signaling to allow submerged rice seedlings to grow.

Planta, 2005

Plant cell walls are composed of independent but interacting networks of carbohydrates, proteins,... more Plant cell walls are composed of independent but interacting networks of carbohydrates, proteins, and aromatic substances. Interacting with this complex matrix are several hundred enzymes and other proteins, some

Journal of Magnetism and Magnetic Materials, 2000

The mixing of (Ni Cu Zn)Fe O powders with Bi O was performed using the solid-state mixing as well... more The mixing of (Ni Cu Zn)Fe O powders with Bi O was performed using the solid-state mixing as well as wet chemical coating processes such as ammonia precipitation coating, urea precipitation coating, and solution coating. Ferrites prepared from the wet chemical coating processes could be densi"ed at a lower sintering temperature without signi"cant impact on the microstructural evolution compared with that prepared by solid-state mixing. In addition, samples prepared from the wet chemical coating process have a higher B and B and a lower H compared with that from solid-state mixing. Considering both the e!ects of sintering temperature and sintered density ('95% T.D.), ferrites with 1.5 wt% Bi O addition by ammonia precipitation coating sintered at 9003C can provide the best permeability and quality factor (191 and 68.2, respectively) among all the cases studied.

Journal of Experimental Botany, 2010

In rice, the class I small heat shock protein (sHSP-CI) genes were found to be selectively induce... more In rice, the class I small heat shock protein (sHSP-CI) genes were found to be selectively induced by L-azetidine-2-carboxylic acid (AZC) on chromosome 3 but not chromosome 1. Here it is shown that a novel cis-responsive element contributed to the differential regulation. By serial deletion and computational analysis, a 9 bp putative AZC-responsive element (AZRE), GTCCTGGAC, located between nucleotides-186 and-178 relative to the transcription initiation site of Oshsp17.3 was revealed. Deletion of this putative AZRE from the promoter abolished its ability to be induced by AZC. Moreover, electrophoretic mobility shift assay (EMSA) revealed that the AZRE interacted specifically with nuclear proteins from AZC-treated rice seedlings. Two AZRE-protein complexes were detected by EMSA, one of which could be competed out by a canonical heat shock element (HSE). Deletion of the AZRE also affected the HS response. Furthermore, transient co-expression of the heat shock factor OsHsfA4b with the AZRE in the promoter of Oshsp17.3 was effective. The requirement for the putative AZRE for AZC and HS responses in transgenic Arabidopsis was also shown. Thus, AZRE represents an alternative form of heat HSE, and its interaction with canonical HSEs through heat shock factors may be required to respond to HS and AZC.

abstracts.aspb.org

The UniformMu maize population is being utilized in a PCR-based reverse genetics approach to iden... more The UniformMu maize population is being utilized in a PCR-based reverse genetics approach to identify Mu-induced knockout mutations of specific cell wall biosynthetic genes. The UniformMu population of the University of Florida is ideal for reverse genetics ...

Journal of Biological Chemistry, 2002

IEEE Transactions on Information Technology in Biomedicine, 2007

This work investigates variable selection and classification for biomedical datasets with a small... more This work investigates variable selection and classification for biomedical datasets with a small sample size and a very high input dimension. The sequential sparse Bayesian learning methods with linear bases are used as the basic variable selection algorithm. Selected variables are fed to the kernel based probabilistic classifiers: Bayesian least squares support vector machines (LS-SVMs) and relevance vector machines (RVMs). We employ the bagging techniques for both variable selection and model building in order to improve the reliability of the selected variables and the predictive performance. This modelling strategy is applied to real-life medical classification problems, including two binary cancer diagnosis problems based on microarray data and a brain tumor multiclass classification problem using spectra acquired via magnetic resonance spectroscopy. The work is experimentally compared to other variable selection methods. It is shown that the use of bagging can improve the reliability and stability of both variable selection and model prediction.

Biotechnology and Bioengineering, 2011

To establish a production platform for recombinant proteins in rice suspension cells, we first co... more To establish a production platform for recombinant proteins in rice suspension cells, we first constructed a Gateway-compatible binary T-DNA destination vector. It provided a reliable and effective method for the rapid directional cloning of target genes into plant cells through Agrobacterium-mediated transformation. We used the approach to produce mouse granulocyte-macrophage colony-stimulating factor (mGM-CSF) in a rice suspension cell system. The promoter for the αAmy3 amylase gene, which is induced strongly by sugar depletion, drove the expression of mGM-CSF. The resulting recombinant protein was fused with the αAmy3 signal peptide and was secreted into the culture medium. The production of rice-derived mGM-CSF (rmGM-CSF) was scaled up successfully in a 2-L bioreactor, in which the highest yield of rmGM-CSF was 24.6 mg/L. Due to post-translational glycosylation, the molecular weight of rmGM-CSF was larger than that of recombinant mGM-CSF produced in Escherichia coli. The rmGM-CSF was bioactive and could stimulate the proliferation of a murine myeloblastic leukemia cell line, NSF-60.

The outstanding strategical target of the Chinese agricultural policy for the upcoming decades ca... more The outstanding strategical target of the Chinese agricultural policy for the upcoming decades can be summarized as follows: producing enough agricultural products under sustainable economic and environmental conditions. One important instrument to address this challenge is the Soil and Fertilizer Information System of China (SOFISC). SOFISC is a GIS.supported computer system especially designed for decision-makers and researchers involved in agricultural and all related industrial and environmental areas of the economy. It provides information about the development of soil fertility and productivity as well as fertilizer application and efficiency in all the 30 provinces and 2,300 counties of China. Future effects of decisions about fertilizer use can be analyzed and evaluated on a national and regional scale.

Fiber Lasers V: Technology, Systems, and Applications, 2008

A new technique for mitigating stimulated Brillouin scattering (SBS) effects in narrow-linewidth ... more A new technique for mitigating stimulated Brillouin scattering (SBS) effects in narrow-linewidth Yb-doped fiber amplifiers is demonstrated with a model that reduces to solving an 8×8 system of coupled nonlinear equations with the gain, SBS, and four-wave mixing (FMW) incorporated into the model. This technique uses two seed signals, or 'two-tones', with each tone reaching its SBS threshold almost independently

SPIE Proceedings, 2014

We present an experimental study on beam combining techniques with multiple vertical external cav... more We present an experimental study on beam combining techniques with multiple vertical external cavity surface emitting lasers (VECSELs) using volume Bragg gratings (VBGs). The specially designed holographic gratings introduce frequency specific feedback for the near infrared wavelength VECSELs to achieve both spectral linewidth narrowing and beam combination effects. For coherent addition, we obtained >3W output power with 8% slope efficiency in a coherent power scaling cavity scheme. In the multiplexed VBGs (MVBGs) wavelength beam combining compound cavity scheme, we measured >6W combined output with nearly 100% combining efficiency. Both beam combining/power scaling schemes produced spectrally narrowed and near diffraction limited outputs.

2011 IEEE/WIC/ACM International Conferences on Web Intelligence and Intelligent Agent Technology, 2011

data points usually pose an approach to al data by efficiently ture, called Geo-tree, d then deve... more data points usually pose an approach to al data by efficiently ture, called Geo-tree, d then develop two geographic data and representation. The oach is very efficient and HAC, and the s. lization; geographic N days are suitable to ems. Compared to ng geographic data information about sers browse (zoom e further messages. the easiest ways to however, it causes

RNA Biology, 2012

largely on the leaf. After detection of the optimal photoperiod, a systemic floral regulator or f... more largely on the leaf. After detection of the optimal photoperiod, a systemic floral regulator or florigen, is synthesized in the leaf. This graft-transmittable signaling molecule then traffics long distance through the phloem to the shoot apices and stimulates floral initiation. 5,6 In an Arabidopsis inducible-promoter system, the RNA of FLOWERING LOCUS T (FT) was suggested to function as a component of florigen. 7 However, the paper was later retracted 8 and subsequent experiments identified that FT protein rather than RNA may function as this long-sought-after florigen. 9,10 Arabidopsis FT encodes an RAF kinase inhibitor-like protein. 11,12 The accumulation of FT RNA depends on light and is positively regulated by CONSTANS (CO), a zinc-finger transcription factor involved in the photoperiodic pathway. 13,14 Both FT and CO are mainly expressed in vascular tissues. 15 When FT or CO was ectopically expressed in the apex, only FT triggered floral initiation, which suggests that FT may act as a systemic floral regulator. 16,17 The identification of the FT-interacting protein FD, a bZIP transcription factor, showed that FD is required for the function of FT. 18,19 Given that FD is specifically expressed in the apex, but FT is predominantly expressed in vascular tissues, FT protein, FT RNA or even

CLEO:2011 - Laser Applications to Photonic Applications, 2011

Abstract Single-frequency coherent beam combination (CBC) of 16 fiber lasers with kW class output... more Abstract Single-frequency coherent beam combination (CBC) of 16 fiber lasers with kW class output power is presented. In addition, kW scale CBC of three Photonic Crystal Fiber (PCF) amplifiers in a filled aperture configuration is reported.

Thin Solid Films, 2000

ABSTRACT

The Plant Cell, 2007

Sugars repress α-amylase expression in germinating embryos and cell cultures of rice (Oryza sativ... more Sugars repress α-amylase expression in germinating embryos and cell cultures of rice (Oryza sativa) through a sugar response complex (SRC) in α-amylase gene promoters and its interacting transcription factor MYBS1. The Snf1 protein kinase is required for the derepression of glucose-repressible genes in yeast. In this study, we explored the role of the yeast Snf1 ortholog in rice, SnRK1, in sugar signaling and plant growth. Rice embryo transient expression assays indicated that SnRK1A and SnRK1B act upstream and relieve glucose repression of MYBS1 and αAmy3 SRC promoters. Both SnRK1s contain N-terminal kinase domains serving as activators and C-terminal regulatory domains as dominant negative regulators of SRC. The accumulation and activity of SnRK1A was regulated by sugars posttranscriptionally, and SnRK1A relieved glucose repression specifically through the TA box in SRC. A transgenic RNA interference approach indicated that SnRK1A is also necessary for the activation of MYBS1 and ...

The Plant Cell, 2002

The expression of ␣-amylase genes in cereals is induced by both gibberellin (GA) and sugar starva... more The expression of ␣-amylase genes in cereals is induced by both gibberellin (GA) and sugar starvation. All ␣-amylase genes isolated from cereals contain a TATCCA element or its variants at positions ‫ف‬ 90 to 150 bp upstream of the transcription start sites. The TATCCA element was shown previously to be an important component of the GA response complex and the sugar response complex of ␣-amylase gene promoters. In the present study, three cDNA clones encoding novel MYB proteins with single DNA binding domains were isolated from a rice suspension cell cDNA library and designated OsMYBS1 , OsMYBS2 , and OsMYBS3. Gel mobility shift experiments with OsMYBSs showed that they bind specifically to the TATCCA element in vitro. Yeast one-hybrid experiments demonstrated that OsMYBS1 and OsMYBS2 bind to the TATCCA element and transactivate a promoter containing the TATCCA element in vivo. Transient expression assays with barley half-seeds showed that OsMYBS1 and OsMYBS2 transactivate a promoter containing the TATCCA element when sugar is provided, whereas OsMYBS3 represses transcription of the same promoter under sugar starvation. Transient expression assays also showed that these three OsMYBSs cooperate with a GA-regulated transcription factor, HvMYBGa, in the transactivation of a low-pI barley ␣-amylase gene promoter in the absence of GA. Two-hybrid experiments with barley half-seeds showed that OsMYBS1 is able to form a homodimer. The present study demonstrates that differential DNA binding affinity, promoter transactivation ability, dimerization, and interactions with other protein factors determine the biological function of OsMYBSs. This study also suggests that common transcription factors are involved in the sugar and hormonal regulation of ␣-amylase gene expression in cereals.

Science Signaling, 2009

The protein kinase CIPK15 integrates the response to hypoxia with sugar signaling to allow submer... more The protein kinase CIPK15 integrates the response to hypoxia with sugar signaling to allow submerged rice seedlings to grow.

Planta, 2005

Plant cell walls are composed of independent but interacting networks of carbohydrates, proteins,... more Plant cell walls are composed of independent but interacting networks of carbohydrates, proteins, and aromatic substances. Interacting with this complex matrix are several hundred enzymes and other proteins, some

Journal of Magnetism and Magnetic Materials, 2000

The mixing of (Ni Cu Zn)Fe O powders with Bi O was performed using the solid-state mixing as well... more The mixing of (Ni Cu Zn)Fe O powders with Bi O was performed using the solid-state mixing as well as wet chemical coating processes such as ammonia precipitation coating, urea precipitation coating, and solution coating. Ferrites prepared from the wet chemical coating processes could be densi"ed at a lower sintering temperature without signi"cant impact on the microstructural evolution compared with that prepared by solid-state mixing. In addition, samples prepared from the wet chemical coating process have a higher B and B and a lower H compared with that from solid-state mixing. Considering both the e!ects of sintering temperature and sintered density ('95% T.D.), ferrites with 1.5 wt% Bi O addition by ammonia precipitation coating sintered at 9003C can provide the best permeability and quality factor (191 and 68.2, respectively) among all the cases studied.

Journal of Experimental Botany, 2010

In rice, the class I small heat shock protein (sHSP-CI) genes were found to be selectively induce... more In rice, the class I small heat shock protein (sHSP-CI) genes were found to be selectively induced by L-azetidine-2-carboxylic acid (AZC) on chromosome 3 but not chromosome 1. Here it is shown that a novel cis-responsive element contributed to the differential regulation. By serial deletion and computational analysis, a 9 bp putative AZC-responsive element (AZRE), GTCCTGGAC, located between nucleotides-186 and-178 relative to the transcription initiation site of Oshsp17.3 was revealed. Deletion of this putative AZRE from the promoter abolished its ability to be induced by AZC. Moreover, electrophoretic mobility shift assay (EMSA) revealed that the AZRE interacted specifically with nuclear proteins from AZC-treated rice seedlings. Two AZRE-protein complexes were detected by EMSA, one of which could be competed out by a canonical heat shock element (HSE). Deletion of the AZRE also affected the HS response. Furthermore, transient co-expression of the heat shock factor OsHsfA4b with the AZRE in the promoter of Oshsp17.3 was effective. The requirement for the putative AZRE for AZC and HS responses in transgenic Arabidopsis was also shown. Thus, AZRE represents an alternative form of heat HSE, and its interaction with canonical HSEs through heat shock factors may be required to respond to HS and AZC.

abstracts.aspb.org

The UniformMu maize population is being utilized in a PCR-based reverse genetics approach to iden... more The UniformMu maize population is being utilized in a PCR-based reverse genetics approach to identify Mu-induced knockout mutations of specific cell wall biosynthetic genes. The UniformMu population of the University of Florida is ideal for reverse genetics ...

Journal of Biological Chemistry, 2002

IEEE Transactions on Information Technology in Biomedicine, 2007

This work investigates variable selection and classification for biomedical datasets with a small... more This work investigates variable selection and classification for biomedical datasets with a small sample size and a very high input dimension. The sequential sparse Bayesian learning methods with linear bases are used as the basic variable selection algorithm. Selected variables are fed to the kernel based probabilistic classifiers: Bayesian least squares support vector machines (LS-SVMs) and relevance vector machines (RVMs). We employ the bagging techniques for both variable selection and model building in order to improve the reliability of the selected variables and the predictive performance. This modelling strategy is applied to real-life medical classification problems, including two binary cancer diagnosis problems based on microarray data and a brain tumor multiclass classification problem using spectra acquired via magnetic resonance spectroscopy. The work is experimentally compared to other variable selection methods. It is shown that the use of bagging can improve the reliability and stability of both variable selection and model prediction.

Biotechnology and Bioengineering, 2011

To establish a production platform for recombinant proteins in rice suspension cells, we first co... more To establish a production platform for recombinant proteins in rice suspension cells, we first constructed a Gateway-compatible binary T-DNA destination vector. It provided a reliable and effective method for the rapid directional cloning of target genes into plant cells through Agrobacterium-mediated transformation. We used the approach to produce mouse granulocyte-macrophage colony-stimulating factor (mGM-CSF) in a rice suspension cell system. The promoter for the αAmy3 amylase gene, which is induced strongly by sugar depletion, drove the expression of mGM-CSF. The resulting recombinant protein was fused with the αAmy3 signal peptide and was secreted into the culture medium. The production of rice-derived mGM-CSF (rmGM-CSF) was scaled up successfully in a 2-L bioreactor, in which the highest yield of rmGM-CSF was 24.6 mg/L. Due to post-translational glycosylation, the molecular weight of rmGM-CSF was larger than that of recombinant mGM-CSF produced in Escherichia coli. The rmGM-CSF was bioactive and could stimulate the proliferation of a murine myeloblastic leukemia cell line, NSF-60.

The outstanding strategical target of the Chinese agricultural policy for the upcoming decades ca... more The outstanding strategical target of the Chinese agricultural policy for the upcoming decades can be summarized as follows: producing enough agricultural products under sustainable economic and environmental conditions. One important instrument to address this challenge is the Soil and Fertilizer Information System of China (SOFISC). SOFISC is a GIS.supported computer system especially designed for decision-makers and researchers involved in agricultural and all related industrial and environmental areas of the economy. It provides information about the development of soil fertility and productivity as well as fertilizer application and efficiency in all the 30 provinces and 2,300 counties of China. Future effects of decisions about fertilizer use can be analyzed and evaluated on a national and regional scale.