Grok Gao - Academia.edu (original) (raw)
Papers by Grok Gao
Infection and …, 1999
Nitric oxide (NO) production by inducible NO synthase (iNOS) during inflammation is an essential ... more Nitric oxide (NO) production by inducible NO synthase (iNOS) during inflammation is an essential element of antimicrobial immunity but can also contribute to host-induced tissue damage. Under conditions of bacterial sepsis, large amounts of NO are produced, causing hypotension, a critical pathological feature of septic shock. In sepsis caused by gram-positive organisms, the bacterial factors contributing to host NO production are poorly characterized. We show that a soluble toxin of Streptococcus pneumoniae, pneumolysin (Pln), is a key component initiating NO production from macrophages. In contrast to wild-type bacteria, a mutant of S. pneumoniae lacking Pln failed to elicit NO production from murine macrophages. Purified recombinant Pln induced NO production at low concentrations and independently of exogenous gamma interferon (IFN-␥) priming of RAW 264.7 macrophages. However, IFN-␥ was essential for Pln-induced NO production, since primary macrophages from mice lacking the IFN-␥ receptor or interferon regulatory factor 1, a transcription factor essential for iNOS expression, failed to produce NO when stimulated with Pln. In addition, Pln acts as an agonist of tumor necrosis factor alpha and interleukin 6 production in macrophages. The properties of Pln, previously identified as a pore-forming hemolysin, also include a role as a general inflammatory agonist.
... Elena; Faculty of Chemistry University of the Basque Country, NanoBio Spectroscopy Group and ... more ... Elena; Faculty of Chemistry University of the Basque Country, NanoBio Spectroscopy Group and ETSF Scientific Development Taha, Jaime; Rice University, Chemistry Balicas, Luis; Florida State University, National High Magnetic Field Lab Mathkar, Akshay; Rice University ...
Brucella canis infects several species of animals, and canine is the preferred host. Genome seque... more Brucella canis infects several species of animals, and canine is the preferred host. Genome sequences of strains from different hosts are valuable for comparative analysis of host adaptation and microevolution. Here, we report the genome sequence of Brucella canis strain 118, a strain isolated from canine.
DNA repair, 2007
The RecQ family of DNA helicases performs essential functions in the maintenance of genomic stabi... more The RecQ family of DNA helicases performs essential functions in the maintenance of genomic stability in all organisms. In Deinococcus radiodurans, DR1289 is a special member of RecQ family with unique arrangement of three tandem HRDC domains in the C-terminus. A dr1289 mutant is hypersensitive to ␥-irradiation, UV, H 2 O 2 and mitomycin C. By complementing the dr1289 mutant with various domains of Dr1289 in vivo, we have determined that the helicase and all three HRDC domains are indispensable for complete DNA damage resistance. Using a continuous fluorescent dye-displacement assay, we investigated the optimal conditions for Dr1289 unwinding function at various concentrations of ATP and metal ions to show that the helicase activity is comparable to what observed in Escherichia coli RecQ. We also found that the helicase domain is necessary for the unwinding and ATPase activity and that the three tandem HRDC domains increase the efficiency of these activities. Based on these data, we propose that the C-terminus of Dr1289 has evolved in D. radiodurans to confront the types and amounts of DNA damage.
A double-layer collector with appropriate profiles has been shown to increase the maximum collect... more A double-layer collector with appropriate profiles has been shown to increase the maximum collector current without compromising the breakdown voltage. Power HBTs with emitter ballasting resistors were grown on Si and GaAs substrates and fabricated to test the various collector designs. A maximum collector current density of 3.5 x 104 A cm-2 and a collector-emitter breakdown voltage of 28 V were realized for a double-layer collector HBT with ten 5 x 25 ~m 2 emitter fingers. This high current density obtained by the novel collector design represents a 60% improvement over the conventional HBT with slightly higher breakdown voltage which is in agreement with predictions.
Transcription factors (TFs) play key roles in controlling gene expression. Systematic identificat... more Transcription factors (TFs) play key roles in controlling gene expression. Systematic identification and annotation of TFs, followed by construction of TF databases may serve as useful resources for studying the function and evolution of transcription factors. We developed a comprehensive plant transcription factor database PlantTFDB (http:// planttfdb.cbi.pku.edu.cn), which contains 26 402 TFs predicted from 22 species, including five model organisms with available whole genome sequence and 17 plants with available EST sequences. To provide comprehensive information for those putative TFs, we made extensive annotation at both family and gene levels. A brief introduction and key references were presented for each family. Functional domain information and crossreferences to various well-known public databases were available for each identified TF. In addition, we predicted putative orthologs of those TFs among the 22 species. PlantTFDB has a simple interface to allow users to search the database by IDs or free texts, to make sequence similarity search against TFs of all or individual species, and to download TF sequences for local analysis.
This paper proposes a novel dual-SAR detector based on the joint metric of interferogram's m... more This paper proposes a novel dual-SAR detector based on the joint metric of interferogram's magnitude and phase for slow ground-moving targets. Motivated by the difference of backscattering properties between slow moving targets and stationary clutter in the SAR image, we devise a new metric for slow ground-moving target detection by combining the interferogram's magnitude and transformed phase. By using simulated data, we demonstrate that this detector can help detect slow moving vehicles within severe ground clutter. Compared to the traditional Displaced Phase Center Antenna (DPCA) and Along-track Interferometry (ATI), this detector performs better because of its higher stabilization, wider range of detection velocity, lower probability of false alarm and higher detection probability.
…, 2006
Transcription factors (TFs) play key roles in regulating gene expression at the transcriptional l... more Transcription factors (TFs) play key roles in regulating gene expression at the transcriptional level, controlling or influencing many biological processes such as development, growth, cell division and responses to environmental stimulus. Identification, characterization and ...
The very long and highly variable latencies in the deep memory hierarchy of a peta op-scale archi... more The very long and highly variable latencies in the deep memory hierarchy of a peta op-scale architecture design, such as the Hybrid Technology Multi-Threaded Architecture (HTMT) 13], present a new challenge to its programming and execution model. A solution to coping with such high and variable latencies is to directly and explicitly expose the di erent memory regions of the machine to the program execution model, allowing better management of communication. In this paper we describe the novel percolation model that lies at the heart of the HTMT program execution model 13]. The Percolation Model combines multithreading with dynamic prefetching of coarse-grain contexts. In the past, prefetching techniques have concentrated on moving blocks of data within the memory hierarchy. Instead of only moving contiguous blocks of data, the thread percolation approach manages contexts that include data, program instructions, and control states. The main contributions of this paper include the speci cation of the HTMT runtime execution model based on the concept of percolation, and a discussion of the role of the compiler in a machine that exposes the memory hierarchy to the programming model.
The attenuation coefficient of photosynthetically available radiation [Kd(PAR)] and three water q... more The attenuation coefficient of photosynthetically available radiation [Kd(PAR)] and three water quality parameters [chlorophyll a (chl a)], chromophoric dissolved organic matter (CDOM) and tripton] were measured at three stations in shallow, subtropical Lake Donghu from April 2003 to March 2004. The multiple regression equation of &(PAR) versus chl a, CDOM, and tripton was: Kd(PAR) = 0.44 + 0.019 chl a + 1.88 CDOM + 0.016 tripton, which revealed the relative contributions of the three parameters to &(PAR). The effects of water and CDOM on Kd(PAR) were of minor importance (19-26%), while chl a and tripton were the two greatest contributors, accounting collectively for 74-81 %.
... Spies and Habashy, 1995; Abubakar et al., 2005) and the subsurface from surface or seafloor m... more ... Spies and Habashy, 1995; Abubakar et al., 2005) and the subsurface from surface or seafloor measurements (Constable et al., 1986; Abubakar et al ... for the resistivity distribution, the joint interpretation of these two types of data is not straightforward (see, for example, Harris et al ...
The influenza A virus is a causative agent of influenza, which infects human cells and uses host ... more The influenza A virus is a causative agent of influenza, which infects human cells and uses host factors to accomplish viral genome replication as part of its life cycle. The nucleoprotein (NP) and PB2 of the influenza virus associate with importin a1 to gain access to the host nucleus through a ternary import complex. Killer cell-mediated cytotoxicity is the primary mechanism of eliminating the influenza virus. Here, we showed that lymphokine-activated killer cells participated in the elimination of the influenza virus. Granzyme (Gzm) K inhibition elevated viral replication in vitro and aggravated viral infection in vivo. We identified that importin a1 and its transport partner protein importin b are physiological substrates of GzmK. Proteolysis of these two substrates wrecked their association to generate the importin a1/b dimer and disrupted transportation of viral NP to the nucleus, leading to inhibition of influenza virus replication.
Electron Devices, IEEE …, 1994
A compact heterojunction bipolar transistor (HBT) model was employed to simulate the high frequen... more A compact heterojunction bipolar transistor (HBT) model was employed to simulate the high frequency and high power performances of SiC-based bipolar transistors. Potential 6H-SiC/3C-SiC heterojunction bipolar transistors (6H/3C-HBT's) at case temperatures of ...
Hispanic Journal of …, 1994
Institution: Google Indexer. Sign In; |; My Tools; |; Contact Us; |; Help. SJO banner. Search all... more Institution: Google Indexer. Sign In; |; My Tools; |; Contact Us; |; Help. SJO banner. Search all journals. Advanced Search Go; Search History Go; Browse Journals Go. Skip to main page content. Home; OnlineFirst; All Issues; Subscribe; RSS rss; Email Alerts. ...
Infection and …, 1999
Nitric oxide (NO) production by inducible NO synthase (iNOS) during inflammation is an essential ... more Nitric oxide (NO) production by inducible NO synthase (iNOS) during inflammation is an essential element of antimicrobial immunity but can also contribute to host-induced tissue damage. Under conditions of bacterial sepsis, large amounts of NO are produced, causing hypotension, a critical pathological feature of septic shock. In sepsis caused by gram-positive organisms, the bacterial factors contributing to host NO production are poorly characterized. We show that a soluble toxin of Streptococcus pneumoniae, pneumolysin (Pln), is a key component initiating NO production from macrophages. In contrast to wild-type bacteria, a mutant of S. pneumoniae lacking Pln failed to elicit NO production from murine macrophages. Purified recombinant Pln induced NO production at low concentrations and independently of exogenous gamma interferon (IFN-␥) priming of RAW 264.7 macrophages. However, IFN-␥ was essential for Pln-induced NO production, since primary macrophages from mice lacking the IFN-␥ receptor or interferon regulatory factor 1, a transcription factor essential for iNOS expression, failed to produce NO when stimulated with Pln. In addition, Pln acts as an agonist of tumor necrosis factor alpha and interleukin 6 production in macrophages. The properties of Pln, previously identified as a pore-forming hemolysin, also include a role as a general inflammatory agonist.
... Elena; Faculty of Chemistry University of the Basque Country, NanoBio Spectroscopy Group and ... more ... Elena; Faculty of Chemistry University of the Basque Country, NanoBio Spectroscopy Group and ETSF Scientific Development Taha, Jaime; Rice University, Chemistry Balicas, Luis; Florida State University, National High Magnetic Field Lab Mathkar, Akshay; Rice University ...
Brucella canis infects several species of animals, and canine is the preferred host. Genome seque... more Brucella canis infects several species of animals, and canine is the preferred host. Genome sequences of strains from different hosts are valuable for comparative analysis of host adaptation and microevolution. Here, we report the genome sequence of Brucella canis strain 118, a strain isolated from canine.
DNA repair, 2007
The RecQ family of DNA helicases performs essential functions in the maintenance of genomic stabi... more The RecQ family of DNA helicases performs essential functions in the maintenance of genomic stability in all organisms. In Deinococcus radiodurans, DR1289 is a special member of RecQ family with unique arrangement of three tandem HRDC domains in the C-terminus. A dr1289 mutant is hypersensitive to ␥-irradiation, UV, H 2 O 2 and mitomycin C. By complementing the dr1289 mutant with various domains of Dr1289 in vivo, we have determined that the helicase and all three HRDC domains are indispensable for complete DNA damage resistance. Using a continuous fluorescent dye-displacement assay, we investigated the optimal conditions for Dr1289 unwinding function at various concentrations of ATP and metal ions to show that the helicase activity is comparable to what observed in Escherichia coli RecQ. We also found that the helicase domain is necessary for the unwinding and ATPase activity and that the three tandem HRDC domains increase the efficiency of these activities. Based on these data, we propose that the C-terminus of Dr1289 has evolved in D. radiodurans to confront the types and amounts of DNA damage.
A double-layer collector with appropriate profiles has been shown to increase the maximum collect... more A double-layer collector with appropriate profiles has been shown to increase the maximum collector current without compromising the breakdown voltage. Power HBTs with emitter ballasting resistors were grown on Si and GaAs substrates and fabricated to test the various collector designs. A maximum collector current density of 3.5 x 104 A cm-2 and a collector-emitter breakdown voltage of 28 V were realized for a double-layer collector HBT with ten 5 x 25 ~m 2 emitter fingers. This high current density obtained by the novel collector design represents a 60% improvement over the conventional HBT with slightly higher breakdown voltage which is in agreement with predictions.
Transcription factors (TFs) play key roles in controlling gene expression. Systematic identificat... more Transcription factors (TFs) play key roles in controlling gene expression. Systematic identification and annotation of TFs, followed by construction of TF databases may serve as useful resources for studying the function and evolution of transcription factors. We developed a comprehensive plant transcription factor database PlantTFDB (http:// planttfdb.cbi.pku.edu.cn), which contains 26 402 TFs predicted from 22 species, including five model organisms with available whole genome sequence and 17 plants with available EST sequences. To provide comprehensive information for those putative TFs, we made extensive annotation at both family and gene levels. A brief introduction and key references were presented for each family. Functional domain information and crossreferences to various well-known public databases were available for each identified TF. In addition, we predicted putative orthologs of those TFs among the 22 species. PlantTFDB has a simple interface to allow users to search the database by IDs or free texts, to make sequence similarity search against TFs of all or individual species, and to download TF sequences for local analysis.
This paper proposes a novel dual-SAR detector based on the joint metric of interferogram's m... more This paper proposes a novel dual-SAR detector based on the joint metric of interferogram's magnitude and phase for slow ground-moving targets. Motivated by the difference of backscattering properties between slow moving targets and stationary clutter in the SAR image, we devise a new metric for slow ground-moving target detection by combining the interferogram's magnitude and transformed phase. By using simulated data, we demonstrate that this detector can help detect slow moving vehicles within severe ground clutter. Compared to the traditional Displaced Phase Center Antenna (DPCA) and Along-track Interferometry (ATI), this detector performs better because of its higher stabilization, wider range of detection velocity, lower probability of false alarm and higher detection probability.
…, 2006
Transcription factors (TFs) play key roles in regulating gene expression at the transcriptional l... more Transcription factors (TFs) play key roles in regulating gene expression at the transcriptional level, controlling or influencing many biological processes such as development, growth, cell division and responses to environmental stimulus. Identification, characterization and ...
The very long and highly variable latencies in the deep memory hierarchy of a peta op-scale archi... more The very long and highly variable latencies in the deep memory hierarchy of a peta op-scale architecture design, such as the Hybrid Technology Multi-Threaded Architecture (HTMT) 13], present a new challenge to its programming and execution model. A solution to coping with such high and variable latencies is to directly and explicitly expose the di erent memory regions of the machine to the program execution model, allowing better management of communication. In this paper we describe the novel percolation model that lies at the heart of the HTMT program execution model 13]. The Percolation Model combines multithreading with dynamic prefetching of coarse-grain contexts. In the past, prefetching techniques have concentrated on moving blocks of data within the memory hierarchy. Instead of only moving contiguous blocks of data, the thread percolation approach manages contexts that include data, program instructions, and control states. The main contributions of this paper include the speci cation of the HTMT runtime execution model based on the concept of percolation, and a discussion of the role of the compiler in a machine that exposes the memory hierarchy to the programming model.
The attenuation coefficient of photosynthetically available radiation [Kd(PAR)] and three water q... more The attenuation coefficient of photosynthetically available radiation [Kd(PAR)] and three water quality parameters [chlorophyll a (chl a)], chromophoric dissolved organic matter (CDOM) and tripton] were measured at three stations in shallow, subtropical Lake Donghu from April 2003 to March 2004. The multiple regression equation of &(PAR) versus chl a, CDOM, and tripton was: Kd(PAR) = 0.44 + 0.019 chl a + 1.88 CDOM + 0.016 tripton, which revealed the relative contributions of the three parameters to &(PAR). The effects of water and CDOM on Kd(PAR) were of minor importance (19-26%), while chl a and tripton were the two greatest contributors, accounting collectively for 74-81 %.
... Spies and Habashy, 1995; Abubakar et al., 2005) and the subsurface from surface or seafloor m... more ... Spies and Habashy, 1995; Abubakar et al., 2005) and the subsurface from surface or seafloor measurements (Constable et al., 1986; Abubakar et al ... for the resistivity distribution, the joint interpretation of these two types of data is not straightforward (see, for example, Harris et al ...
The influenza A virus is a causative agent of influenza, which infects human cells and uses host ... more The influenza A virus is a causative agent of influenza, which infects human cells and uses host factors to accomplish viral genome replication as part of its life cycle. The nucleoprotein (NP) and PB2 of the influenza virus associate with importin a1 to gain access to the host nucleus through a ternary import complex. Killer cell-mediated cytotoxicity is the primary mechanism of eliminating the influenza virus. Here, we showed that lymphokine-activated killer cells participated in the elimination of the influenza virus. Granzyme (Gzm) K inhibition elevated viral replication in vitro and aggravated viral infection in vivo. We identified that importin a1 and its transport partner protein importin b are physiological substrates of GzmK. Proteolysis of these two substrates wrecked their association to generate the importin a1/b dimer and disrupted transportation of viral NP to the nucleus, leading to inhibition of influenza virus replication.
Electron Devices, IEEE …, 1994
A compact heterojunction bipolar transistor (HBT) model was employed to simulate the high frequen... more A compact heterojunction bipolar transistor (HBT) model was employed to simulate the high frequency and high power performances of SiC-based bipolar transistors. Potential 6H-SiC/3C-SiC heterojunction bipolar transistors (6H/3C-HBT's) at case temperatures of ...
Hispanic Journal of …, 1994
Institution: Google Indexer. Sign In; |; My Tools; |; Contact Us; |; Help. SJO banner. Search all... more Institution: Google Indexer. Sign In; |; My Tools; |; Contact Us; |; Help. SJO banner. Search all journals. Advanced Search Go; Search History Go; Browse Journals Go. Skip to main page content. Home; OnlineFirst; All Issues; Subscribe; RSS rss; Email Alerts. ...