van luong nguyen - Profile on Academia.edu (original) (raw)
Papers by van luong nguyen
Variational inequalities governed by strongly pseudomonotone vector fields on Hadamard manifolds
Applicable Analysis
Journal of Imaging
Compared to single source systems, stereo X-ray CT systems allow acquiring projection data within... more Compared to single source systems, stereo X-ray CT systems allow acquiring projection data within a reduced amount of time, for an extended field-of-view, or for dual X-ray energies. To exploit the benefit of a dual X-ray system, its acquisition geometry needs to be calibrated. Unfortunately, in modular stereo X-ray CT setups, geometry misalignment occurs each time the setup is changed, which calls for an efficient calibration procedure. Although many studies have been dealing with geometry calibration of an X-ray CT system, little research targets the calibration of a dual cone-beam X-ray CT system. In this work, we present a phantom-based calibration procedure to accurately estimate the geometry of a stereo cone-beam X-ray CT system. With simulated as well as real experiments, it is shown that the calibration procedure can be used to accurately estimate the geometry of a modular stereo X-ray CT system thereby reducing the misalignment artifacts in the reconstruction volumes.
Mechanical Behavior of Sn-3.0Ag-0.5Cu/Cu Solder Joints After Isothermal Aging
Journal of Electronic Materials, 2015
Seed-Based Parallel Protein Sequence Comparison Combining Multithreading, GPU, and FPGA Technologies
Embedded Multi-Core Systems, 2010
2008 Ninth International Conference on Parallel and Distributed Computing, Applications and Technologies, 2008
This paper introduces the Godson-T manycore architecture and demonstrates the efficiency of its s... more This paper introduces the Godson-T manycore architecture and demonstrates the efficiency of its synchronization mechanism through a computation intensive bioinformatics application: the comparison of protein banks. The parallel part of the protein sequence comparison algorithm can nearly get a linear speed-up thanks to a fine tuning of the synchronization mechanism provided by the Godson-T chip.
Journal of Electronic Materials, 2014
In this study we expanded on recently reported research by using a modified miniature Charpy impa... more In this study we expanded on recently reported research by using a modified miniature Charpy impact-testing system to investigate the shear deformation behavior of Sn-3.0Ag-0.5Cu lead-free solder joints at high strain rates ranging from 1.1 9 10 3 s À1 to 5.5 9 10 3 s À1. The experimental results revealed that the maximum shear strength of the solder joint decreased with increasing load speed in the ranges tested in this study. For solder joints tested at a shear speed exceeding 1 m/s, corresponding to an approximate strain rate that exceeds 1950 s À1 , the brittle fracture mode is the main failure mode, whereas lower strain rates result in a ductile-to-brittle transition in the fracture surfaces of solder joints. In addition, the mode II stress intensity factor (K II) used to evaluate the fracture toughness (K C) of an interfacial intermetallic compound layer between Sn-3.0Ag-0.5Cu solder and the toughness of copper substrate was found to decrease from 1.63 MPa m 0.5 to 0.97 MPa m 0.5 in the speed range tested here.
Block interleaving for soft decision Viterbi decoding in OFDM systems
IEEE 54th Vehicular Technology Conference. VTC Fall 2001. Proceedings (Cat. No.01CH37211), 2001
In this paper, frequency and time interleaving algorithms used for soft decision Viterbi decoding... more In this paper, frequency and time interleaving algorithms used for soft decision Viterbi decoding for OFDM systems, performed on frequency-selective and time-selective channels respectively, are investigated. To achieve optimal performance in terms of the bit error rate (BER), the size of the interleavers must be specified depending on the properties of the channel and the characteristics of the code. Under
Performance analysis of the VBLAST algorithm for MIMO-OFDMA systems on spatial correlated channels
ABSTRACT This paper investigates the performance of Vertical Bell Laboratories Layered Space Time... more ABSTRACT This paper investigates the performance of Vertical Bell Laboratories Layered Space Time (V-BLAST) architecture for multi input multi output orthogonal frequency division multiple access (MIMO-OFDMA) system. VBLAST is a successive cancellation method applied to the receiver to obtain the highest SNR. Performance of MIMO systems in realistic radio environments greatly depends on the spatial correlation due to the presence of scatterers in the multipath propagation environments.The number of users using in the system are also analyzed. It is assumed that all antennas have same radiation pattern and the spatial correlation is independent on the position of an antenna in the array. Our results are simulated on Monte Carlo and One Ring channel model for 2x2 MIMO OFDMA system. From the results, we can see that VBLAST-ZF show the best SER performance in one ring channel model with long term evolution (LTE) standard.
Cytotoxic Prenylated Isoflavone and Bipterocarpan from Millettia pachyloba
Planta Medica, 2010
Two new compounds, an isoflavone (1, 6-methoxybarbigerone) and a bipterocarpan (2, pachylobin) we... more Two new compounds, an isoflavone (1, 6-methoxybarbigerone) and a bipterocarpan (2, pachylobin) were isolated from the grains of Millettia pachyloba (Leguminosae), together with seven known compounds, 5-methoxybarbigerone (3), calopogoniumisoflavone B (4), durmillone (5), jamaicin (6), ichthynone (7), (-)-pisatin (8) and (-)-rotenone (9). The structures were established from spectroscopic analyses, including mass spectrometry and 2D-NMR. Absolute configuration of 2 was proposed based on that of the known compound (-)-pisatine (8). Compounds 1 and 2 exhibited cytotoxicity against KB cells with IC(50) values of 2.0 and 17.6 µM, respectively.
Microbial Cell Factories, 2011
Background Disulfide bonds are one of the most common post-translational modifications found in p... more Background Disulfide bonds are one of the most common post-translational modifications found in proteins. The production of proteins that contain native disulfide bonds is challenging, especially on a large scale. Either the protein needs to be targeted to the endoplasmic reticulum in eukaryotes or to the prokaryotic periplasm. These compartments that are specialised for disulfide bond formation have an active catalyst for their formation, along with catalysts for isomerization to the native state. We have recently shown that it is possible to produce large amounts of prokaryotic disulfide bond containing proteins in the cytoplasm of wild-type bacteria such as E. coli by the introduction of catalysts for both of these processes. Results Here we show that the introduction of Erv1p, a sulfhydryl oxidase and a disulfide isomerase allows the efficient formation of natively folded eukaryotic proteins with multiple disulfide bonds in the cytoplasm of E. coli. The production of disulfide b...
Journal of Natural Products, 2012
Journal of Chromatography B, 2011
International Journal of Behavioral Nutrition and Physical Activity, 2011
Background Comprehensive, multi-level approaches are required to address obesity. One important t... more Background Comprehensive, multi-level approaches are required to address obesity. One important target for intervention is the economic domain. The purpose of this study was to synthesize existing evidence regarding the impact of economic policies targeting obesity and its causal behaviours (diet, physical activity), and to make specific recommendations for the Canadian context. 2 Conclusions In terms of economic interventions, shifting from empirical evidence to policy recommendation remains challenging. Overall, the evidence is not sufficiently strong to provide clear policy direction. Additionally, the nature of the experiments needed to provide definitive evidence supporting certain policy directions is likely to be complex and potentially unfeasible. However, these are not reasons to take no action. It is likely that policies need to be implemented in the face of an incomplete evidence base.
Preparation and characterization of P(VDF-TrFE)/Al2O3 nanocomposite
IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control, 2000
Hybrid nanocomposites based on crystalline nanoparticles dispersed in polymer matrix have been wi... more Hybrid nanocomposites based on crystalline nanoparticles dispersed in polymer matrix have been widely studied in the past few years because of the ability of these materials to combine the properties of organic polymer and inorganic nanoparticles. The aim of this work is to tune the mechanical properties of a piezoelectric polymer by adding nanoparticles to the matrix. In this paper, alumina nanoparticles were dispersed in the copolymer P(VDF-TrFE), which exhibits high piezoelectric coefficient after polarization under high electric field without needing stretching during the polarization process. Transmission electron microscopy and scanning electron microscopy demonstrate the high rate of welldispersed nanoparticles with 10% of alumina nanoparticles added to the matrix. Piezoelectric measurements indicate that P(VDF-TrFE) may be filled by up to 10 wt% of alumina while retaining its high piezoelectric properties and increasing its elastic constant by more than 20%, measured by Brillouin spectroscopy. This work opens a wide range of applications using nanoparticles with nonlinear optical, pyroelectric, magnetic, or ferroelectric properties.
BMC Health Services Research, 2012
Background: Cardiovascular disease (CVD) is a leading cause of death in Canada and is a priority ... more Background: Cardiovascular disease (CVD) is a leading cause of death in Canada and is a priority area for medical research. The research funding landscape in Canada has changed quite a bit over the last few decades, as have funding levels. Our objective was to estimate the magnitude of expenditures on CVD research for the public and charitable (not-for profit) sectors in Canada between 1975 and 2005. Methods: To estimate research expenditures for the public and charitable sectors, we compiled a complete list of granting agencies in Canada, contacted each agency and the Canadian Institutes of Health Research (CIHR), and extracted data from the organizations' annual reports and the Reference Lists of health research in Canada. Two independent reviewers scanned all grant and fellowship/scholarship titles (and summary/key words, when available) of all research projects funded to determine their inclusion in our analysis; only grants and fellowships/scholarships that focused on heart and peripheral vascular diseases were selected. Results: Public/charitable sector funding increased 7.5 times, from close to 13million(inconstantdollars)in1975toalmost13 million (in constant dollars) in 1975 to almost 13million(inconstantdollars)in1975toalmost96 million (in constant dollars) in 2005 (base year). The Medical Research Council of Canada (MRCC)/ CIHR and the Heart & Stroke Foundation of Canada have been the main founders of this type of research during our analysis period; the Alberta Heritage Foundation for Medical Research and the Fonds de la recherche en santé du Quebec have played major roles at the provincial level. The Indirect Costs Research Program and Canada Foundation for Innovation have played major roles in terms of funding in the last years of our analysis. Conclusion: Public/charitable-funded research expenditures devoted to CVD have increased substantially over the last three decades. By international standards, the evidence suggests Canada spends less on health-related research than the UK and the US, at least in absolute terms. However, this may not be too problematic as Canada is likely to free-ride from research undertaken elsewhere. Understanding these past trends in research funding may provide decision makers with important information for planning future research efforts. Future work in this area should include the use of our coding methods to obtain estimates of funded research for other diseases in Canada.
BMC Bioinformatics, 2009
Background: Sequence similarity searching is an important and challenging task in molecular biolo... more Background: Sequence similarity searching is an important and challenging task in molecular biology and next-generation sequencing should further strengthen the need for faster algorithms to process such vast amounts of data. At the same time, the internal architecture of current microprocessors is tending towards more parallelism, leading to the use of chips with two, four and more cores integrated on the same die. The main purpose of this work was to design an effective algorithm to fit with the parallel capabilities of modern microprocessors. Results: A parallel algorithm for comparing large genomic banks and targeting middle-range computers has been developed and implemented in PLAST software. The algorithm exploits two key parallel features of existing and future microprocessors: the SIMD programming model (SSE instruction set) and the multithreading concept (multicore). Compared to multithreaded BLAST software, tests performed on an 8-processor server have shown speedup ranging from 3 to 6 with a similar level of accuracy. Conclusion: A parallel algorithmic approach driven by the knowledge of the internal microprocessor architecture allows significant speedup to be obtained while preserving standard sensitivity for similarity search problems.
Biochemistry, 2004
The gonadotropins, luteinizing hormone (LH), follicle-stimulating hormone (FSH), and chorionic go... more The gonadotropins, luteinizing hormone (LH), follicle-stimulating hormone (FSH), and chorionic gonadotropin (CG), are cysteine-knot growth-factor superfamily glycoproteins composed of a common R subunit noncovalently associated with a hormone-specific subunit. The cysteine-knot motifs in both subunits create two hairpin loops, designated L1 and L3, on one side of the knot, with the intervening long loop, L2, on the opposite side. As the average R-subunit loop 2 oligosaccharide mass increased from 1482 to 2327, LH and FSH receptor-binding affinities of the dual-specificity eLH declined significantly, while the decrease in FSH receptor-binding affinity for eFSH was not significant. In the present study, we characterized hormone-specific glycosylation of RL2 oligosaccharides in eLHR, eFSHR, and eCGR preparations. MALDI mass spectrometry revealed 28-57 structures, including high mannose, hybrid, bi-, and triantennary oligosaccharides. The same intact subunit preparations and their RL2 loopdeglycosylated derivatives were combined with either eLH or eFSH , and the circular dichroism (CD) spectrum for each preparation was determined. We predicted that hybrid hormone preparations obtained by combining intact eLHR, eFSHR, and eCGR preparations with eLH might exhibit differences in conformation that would disappear when the RL2 oligosaccharide attached to RAsn 56 was removed by selective peptide-N-glycanase digestion (N 56 dg-R). CD data supported the first prediction; however, elimination of RL2 oligosaccharide actually increased the conformational differences. The intact R subunit: eFSH hybrids had virtually identical CD spectra, as expected. However, the N 56 dg-R:eFSH hybrid spectra differed from each other. Oligosaccharide removal altered the conformation of most hybrids, suggesting that RAsn 82 oligosaccharide (located in RL3) also influenced gonadotropin conformation.
Drug abuse in Vietnam: a critical review of the literature and implications for future research
Addiction, 2008
To provide an overall picture of drug abuse in Vietnam, its prevalence, correlates and patterns. ... more To provide an overall picture of drug abuse in Vietnam, its prevalence, correlates and patterns. Studies addressing the drug abuse problem in Vietnam are reviewed. Attention is paid to studies conducted from 1993 onwards. The reviewed studies were collected from both refereed and non-refereed sources. Drug abuse is rising sharply in Vietnam: almost threefold over the past 10 years. From a predominantly rural-mountainous phenomenon, illicit drug abuse spread rapidly to urban areas. Meanwhile, the average age of drug users has declined and more women have been engaging in drug consumption. At the same time, heroin has replaced opium as the most preferred drug in the country's illicit drug market, especially among young users in urban areas. At the national level, the second main route of drug administration, injecting, has exceeded smoking and taken precedence in the…
Heterogeneity and genetic variations of serotypes O and Asia 1 foot-and-mouth disease viruses isolated in Vietnam
Six field foot-and-mouth disease viruses (FMDVs), including four serotype O and two serotype Asia... more Six field foot-and-mouth disease viruses (FMDVs), including four serotype O and two serotype Asia 1 strains, were collected from endemic outbreaks in 2005, 2006, and 2007 from four different provinces in Vietnam. The viruses were isolated and genetically characterized for their complete genomic sequences. The genetic analysis based on the complete genomic coding sequences revealed that the four serotype O FMDVs were related to each other, sharing 95.2% nucleotide (nt) identity and 97.5-97.6% amino acid (aa) identity. Genetic analysis and a phylogenetic tree, based on the VP1 gene of FMDV, showed that the four present Vietnamese serotype O strains have a high level of identity with other serotype O representatives of the Mya-98 lineage of the Southeast Asian (SEA) topotype. The four viruses were all clustered into the Mya-98 lineage of the SEA topotype, sharing 92.3-95.6% nt and 93.4-96.7% aa identity. This finding of the Mya-98 lineage was different from previous reports that the Vietnamese serotype O strains belonged to the Cam-94 lineage of the SEA topotype and two other topotypes, Middle East-South Asia (ME-SA) and Cathay. For the two serotype Asia 1 FMDVs, the genetic analysis based on the complete genomic coding sequences as well as on the VP1 gene revealed that they belonged to two genogroups, IV and V. Of note, the As1/VN/QT03/2007 strain of genogroup V, isolated in 2007, was very closely related to the pandemic Asia 1 strain which caused FMD outbreaks in China (Asia1/WHN/CHA/06, FJ906802) and Mongolia (Asia1/MOG/05, EF614458) in 2005, sharing 99.0-99.3% nt and 99.5-100% aa identity. In contrast, the second strain As1/VN/LC04/2005 of genogroup IV, isolated in 2005, was closely related to all referenced Vietnamese serotype Asia 1 strains found in the GenBank databases, sharing 86.4-100% nt and 90.9-100% aa identity with each. This study is the first description of the full-length genomic sequence of Vietnamese FMDV serotypes O and Asia 1 and may provide the evidence of the concurrent circulation of different serotypes and subtypes of FMDV in recent years in Vietnam.
Variational inequalities governed by strongly pseudomonotone vector fields on Hadamard manifolds
Applicable Analysis
Journal of Imaging
Compared to single source systems, stereo X-ray CT systems allow acquiring projection data within... more Compared to single source systems, stereo X-ray CT systems allow acquiring projection data within a reduced amount of time, for an extended field-of-view, or for dual X-ray energies. To exploit the benefit of a dual X-ray system, its acquisition geometry needs to be calibrated. Unfortunately, in modular stereo X-ray CT setups, geometry misalignment occurs each time the setup is changed, which calls for an efficient calibration procedure. Although many studies have been dealing with geometry calibration of an X-ray CT system, little research targets the calibration of a dual cone-beam X-ray CT system. In this work, we present a phantom-based calibration procedure to accurately estimate the geometry of a stereo cone-beam X-ray CT system. With simulated as well as real experiments, it is shown that the calibration procedure can be used to accurately estimate the geometry of a modular stereo X-ray CT system thereby reducing the misalignment artifacts in the reconstruction volumes.
Mechanical Behavior of Sn-3.0Ag-0.5Cu/Cu Solder Joints After Isothermal Aging
Journal of Electronic Materials, 2015
Seed-Based Parallel Protein Sequence Comparison Combining Multithreading, GPU, and FPGA Technologies
Embedded Multi-Core Systems, 2010
2008 Ninth International Conference on Parallel and Distributed Computing, Applications and Technologies, 2008
This paper introduces the Godson-T manycore architecture and demonstrates the efficiency of its s... more This paper introduces the Godson-T manycore architecture and demonstrates the efficiency of its synchronization mechanism through a computation intensive bioinformatics application: the comparison of protein banks. The parallel part of the protein sequence comparison algorithm can nearly get a linear speed-up thanks to a fine tuning of the synchronization mechanism provided by the Godson-T chip.
Journal of Electronic Materials, 2014
In this study we expanded on recently reported research by using a modified miniature Charpy impa... more In this study we expanded on recently reported research by using a modified miniature Charpy impact-testing system to investigate the shear deformation behavior of Sn-3.0Ag-0.5Cu lead-free solder joints at high strain rates ranging from 1.1 9 10 3 s À1 to 5.5 9 10 3 s À1. The experimental results revealed that the maximum shear strength of the solder joint decreased with increasing load speed in the ranges tested in this study. For solder joints tested at a shear speed exceeding 1 m/s, corresponding to an approximate strain rate that exceeds 1950 s À1 , the brittle fracture mode is the main failure mode, whereas lower strain rates result in a ductile-to-brittle transition in the fracture surfaces of solder joints. In addition, the mode II stress intensity factor (K II) used to evaluate the fracture toughness (K C) of an interfacial intermetallic compound layer between Sn-3.0Ag-0.5Cu solder and the toughness of copper substrate was found to decrease from 1.63 MPa m 0.5 to 0.97 MPa m 0.5 in the speed range tested here.
Block interleaving for soft decision Viterbi decoding in OFDM systems
IEEE 54th Vehicular Technology Conference. VTC Fall 2001. Proceedings (Cat. No.01CH37211), 2001
In this paper, frequency and time interleaving algorithms used for soft decision Viterbi decoding... more In this paper, frequency and time interleaving algorithms used for soft decision Viterbi decoding for OFDM systems, performed on frequency-selective and time-selective channels respectively, are investigated. To achieve optimal performance in terms of the bit error rate (BER), the size of the interleavers must be specified depending on the properties of the channel and the characteristics of the code. Under
Performance analysis of the VBLAST algorithm for MIMO-OFDMA systems on spatial correlated channels
ABSTRACT This paper investigates the performance of Vertical Bell Laboratories Layered Space Time... more ABSTRACT This paper investigates the performance of Vertical Bell Laboratories Layered Space Time (V-BLAST) architecture for multi input multi output orthogonal frequency division multiple access (MIMO-OFDMA) system. VBLAST is a successive cancellation method applied to the receiver to obtain the highest SNR. Performance of MIMO systems in realistic radio environments greatly depends on the spatial correlation due to the presence of scatterers in the multipath propagation environments.The number of users using in the system are also analyzed. It is assumed that all antennas have same radiation pattern and the spatial correlation is independent on the position of an antenna in the array. Our results are simulated on Monte Carlo and One Ring channel model for 2x2 MIMO OFDMA system. From the results, we can see that VBLAST-ZF show the best SER performance in one ring channel model with long term evolution (LTE) standard.
Cytotoxic Prenylated Isoflavone and Bipterocarpan from Millettia pachyloba
Planta Medica, 2010
Two new compounds, an isoflavone (1, 6-methoxybarbigerone) and a bipterocarpan (2, pachylobin) we... more Two new compounds, an isoflavone (1, 6-methoxybarbigerone) and a bipterocarpan (2, pachylobin) were isolated from the grains of Millettia pachyloba (Leguminosae), together with seven known compounds, 5-methoxybarbigerone (3), calopogoniumisoflavone B (4), durmillone (5), jamaicin (6), ichthynone (7), (-)-pisatin (8) and (-)-rotenone (9). The structures were established from spectroscopic analyses, including mass spectrometry and 2D-NMR. Absolute configuration of 2 was proposed based on that of the known compound (-)-pisatine (8). Compounds 1 and 2 exhibited cytotoxicity against KB cells with IC(50) values of 2.0 and 17.6 µM, respectively.
Microbial Cell Factories, 2011
Background Disulfide bonds are one of the most common post-translational modifications found in p... more Background Disulfide bonds are one of the most common post-translational modifications found in proteins. The production of proteins that contain native disulfide bonds is challenging, especially on a large scale. Either the protein needs to be targeted to the endoplasmic reticulum in eukaryotes or to the prokaryotic periplasm. These compartments that are specialised for disulfide bond formation have an active catalyst for their formation, along with catalysts for isomerization to the native state. We have recently shown that it is possible to produce large amounts of prokaryotic disulfide bond containing proteins in the cytoplasm of wild-type bacteria such as E. coli by the introduction of catalysts for both of these processes. Results Here we show that the introduction of Erv1p, a sulfhydryl oxidase and a disulfide isomerase allows the efficient formation of natively folded eukaryotic proteins with multiple disulfide bonds in the cytoplasm of E. coli. The production of disulfide b...
Journal of Natural Products, 2012
Journal of Chromatography B, 2011
International Journal of Behavioral Nutrition and Physical Activity, 2011
Background Comprehensive, multi-level approaches are required to address obesity. One important t... more Background Comprehensive, multi-level approaches are required to address obesity. One important target for intervention is the economic domain. The purpose of this study was to synthesize existing evidence regarding the impact of economic policies targeting obesity and its causal behaviours (diet, physical activity), and to make specific recommendations for the Canadian context. 2 Conclusions In terms of economic interventions, shifting from empirical evidence to policy recommendation remains challenging. Overall, the evidence is not sufficiently strong to provide clear policy direction. Additionally, the nature of the experiments needed to provide definitive evidence supporting certain policy directions is likely to be complex and potentially unfeasible. However, these are not reasons to take no action. It is likely that policies need to be implemented in the face of an incomplete evidence base.
Preparation and characterization of P(VDF-TrFE)/Al2O3 nanocomposite
IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control, 2000
Hybrid nanocomposites based on crystalline nanoparticles dispersed in polymer matrix have been wi... more Hybrid nanocomposites based on crystalline nanoparticles dispersed in polymer matrix have been widely studied in the past few years because of the ability of these materials to combine the properties of organic polymer and inorganic nanoparticles. The aim of this work is to tune the mechanical properties of a piezoelectric polymer by adding nanoparticles to the matrix. In this paper, alumina nanoparticles were dispersed in the copolymer P(VDF-TrFE), which exhibits high piezoelectric coefficient after polarization under high electric field without needing stretching during the polarization process. Transmission electron microscopy and scanning electron microscopy demonstrate the high rate of welldispersed nanoparticles with 10% of alumina nanoparticles added to the matrix. Piezoelectric measurements indicate that P(VDF-TrFE) may be filled by up to 10 wt% of alumina while retaining its high piezoelectric properties and increasing its elastic constant by more than 20%, measured by Brillouin spectroscopy. This work opens a wide range of applications using nanoparticles with nonlinear optical, pyroelectric, magnetic, or ferroelectric properties.
BMC Health Services Research, 2012
Background: Cardiovascular disease (CVD) is a leading cause of death in Canada and is a priority ... more Background: Cardiovascular disease (CVD) is a leading cause of death in Canada and is a priority area for medical research. The research funding landscape in Canada has changed quite a bit over the last few decades, as have funding levels. Our objective was to estimate the magnitude of expenditures on CVD research for the public and charitable (not-for profit) sectors in Canada between 1975 and 2005. Methods: To estimate research expenditures for the public and charitable sectors, we compiled a complete list of granting agencies in Canada, contacted each agency and the Canadian Institutes of Health Research (CIHR), and extracted data from the organizations' annual reports and the Reference Lists of health research in Canada. Two independent reviewers scanned all grant and fellowship/scholarship titles (and summary/key words, when available) of all research projects funded to determine their inclusion in our analysis; only grants and fellowships/scholarships that focused on heart and peripheral vascular diseases were selected. Results: Public/charitable sector funding increased 7.5 times, from close to 13million(inconstantdollars)in1975toalmost13 million (in constant dollars) in 1975 to almost 13million(inconstantdollars)in1975toalmost96 million (in constant dollars) in 2005 (base year). The Medical Research Council of Canada (MRCC)/ CIHR and the Heart & Stroke Foundation of Canada have been the main founders of this type of research during our analysis period; the Alberta Heritage Foundation for Medical Research and the Fonds de la recherche en santé du Quebec have played major roles at the provincial level. The Indirect Costs Research Program and Canada Foundation for Innovation have played major roles in terms of funding in the last years of our analysis. Conclusion: Public/charitable-funded research expenditures devoted to CVD have increased substantially over the last three decades. By international standards, the evidence suggests Canada spends less on health-related research than the UK and the US, at least in absolute terms. However, this may not be too problematic as Canada is likely to free-ride from research undertaken elsewhere. Understanding these past trends in research funding may provide decision makers with important information for planning future research efforts. Future work in this area should include the use of our coding methods to obtain estimates of funded research for other diseases in Canada.
BMC Bioinformatics, 2009
Background: Sequence similarity searching is an important and challenging task in molecular biolo... more Background: Sequence similarity searching is an important and challenging task in molecular biology and next-generation sequencing should further strengthen the need for faster algorithms to process such vast amounts of data. At the same time, the internal architecture of current microprocessors is tending towards more parallelism, leading to the use of chips with two, four and more cores integrated on the same die. The main purpose of this work was to design an effective algorithm to fit with the parallel capabilities of modern microprocessors. Results: A parallel algorithm for comparing large genomic banks and targeting middle-range computers has been developed and implemented in PLAST software. The algorithm exploits two key parallel features of existing and future microprocessors: the SIMD programming model (SSE instruction set) and the multithreading concept (multicore). Compared to multithreaded BLAST software, tests performed on an 8-processor server have shown speedup ranging from 3 to 6 with a similar level of accuracy. Conclusion: A parallel algorithmic approach driven by the knowledge of the internal microprocessor architecture allows significant speedup to be obtained while preserving standard sensitivity for similarity search problems.
Biochemistry, 2004
The gonadotropins, luteinizing hormone (LH), follicle-stimulating hormone (FSH), and chorionic go... more The gonadotropins, luteinizing hormone (LH), follicle-stimulating hormone (FSH), and chorionic gonadotropin (CG), are cysteine-knot growth-factor superfamily glycoproteins composed of a common R subunit noncovalently associated with a hormone-specific subunit. The cysteine-knot motifs in both subunits create two hairpin loops, designated L1 and L3, on one side of the knot, with the intervening long loop, L2, on the opposite side. As the average R-subunit loop 2 oligosaccharide mass increased from 1482 to 2327, LH and FSH receptor-binding affinities of the dual-specificity eLH declined significantly, while the decrease in FSH receptor-binding affinity for eFSH was not significant. In the present study, we characterized hormone-specific glycosylation of RL2 oligosaccharides in eLHR, eFSHR, and eCGR preparations. MALDI mass spectrometry revealed 28-57 structures, including high mannose, hybrid, bi-, and triantennary oligosaccharides. The same intact subunit preparations and their RL2 loopdeglycosylated derivatives were combined with either eLH or eFSH , and the circular dichroism (CD) spectrum for each preparation was determined. We predicted that hybrid hormone preparations obtained by combining intact eLHR, eFSHR, and eCGR preparations with eLH might exhibit differences in conformation that would disappear when the RL2 oligosaccharide attached to RAsn 56 was removed by selective peptide-N-glycanase digestion (N 56 dg-R). CD data supported the first prediction; however, elimination of RL2 oligosaccharide actually increased the conformational differences. The intact R subunit: eFSH hybrids had virtually identical CD spectra, as expected. However, the N 56 dg-R:eFSH hybrid spectra differed from each other. Oligosaccharide removal altered the conformation of most hybrids, suggesting that RAsn 82 oligosaccharide (located in RL3) also influenced gonadotropin conformation.
Drug abuse in Vietnam: a critical review of the literature and implications for future research
Addiction, 2008
To provide an overall picture of drug abuse in Vietnam, its prevalence, correlates and patterns. ... more To provide an overall picture of drug abuse in Vietnam, its prevalence, correlates and patterns. Studies addressing the drug abuse problem in Vietnam are reviewed. Attention is paid to studies conducted from 1993 onwards. The reviewed studies were collected from both refereed and non-refereed sources. Drug abuse is rising sharply in Vietnam: almost threefold over the past 10 years. From a predominantly rural-mountainous phenomenon, illicit drug abuse spread rapidly to urban areas. Meanwhile, the average age of drug users has declined and more women have been engaging in drug consumption. At the same time, heroin has replaced opium as the most preferred drug in the country's illicit drug market, especially among young users in urban areas. At the national level, the second main route of drug administration, injecting, has exceeded smoking and taken precedence in the…
Heterogeneity and genetic variations of serotypes O and Asia 1 foot-and-mouth disease viruses isolated in Vietnam
Six field foot-and-mouth disease viruses (FMDVs), including four serotype O and two serotype Asia... more Six field foot-and-mouth disease viruses (FMDVs), including four serotype O and two serotype Asia 1 strains, were collected from endemic outbreaks in 2005, 2006, and 2007 from four different provinces in Vietnam. The viruses were isolated and genetically characterized for their complete genomic sequences. The genetic analysis based on the complete genomic coding sequences revealed that the four serotype O FMDVs were related to each other, sharing 95.2% nucleotide (nt) identity and 97.5-97.6% amino acid (aa) identity. Genetic analysis and a phylogenetic tree, based on the VP1 gene of FMDV, showed that the four present Vietnamese serotype O strains have a high level of identity with other serotype O representatives of the Mya-98 lineage of the Southeast Asian (SEA) topotype. The four viruses were all clustered into the Mya-98 lineage of the SEA topotype, sharing 92.3-95.6% nt and 93.4-96.7% aa identity. This finding of the Mya-98 lineage was different from previous reports that the Vietnamese serotype O strains belonged to the Cam-94 lineage of the SEA topotype and two other topotypes, Middle East-South Asia (ME-SA) and Cathay. For the two serotype Asia 1 FMDVs, the genetic analysis based on the complete genomic coding sequences as well as on the VP1 gene revealed that they belonged to two genogroups, IV and V. Of note, the As1/VN/QT03/2007 strain of genogroup V, isolated in 2007, was very closely related to the pandemic Asia 1 strain which caused FMD outbreaks in China (Asia1/WHN/CHA/06, FJ906802) and Mongolia (Asia1/MOG/05, EF614458) in 2005, sharing 99.0-99.3% nt and 99.5-100% aa identity. In contrast, the second strain As1/VN/LC04/2005 of genogroup IV, isolated in 2005, was closely related to all referenced Vietnamese serotype Asia 1 strains found in the GenBank databases, sharing 86.4-100% nt and 90.9-100% aa identity with each. This study is the first description of the full-length genomic sequence of Vietnamese FMDV serotypes O and Asia 1 and may provide the evidence of the concurrent circulation of different serotypes and subtypes of FMDV in recent years in Vietnam.