Kevin Torres - Academia.edu (original) (raw)
Papers by Kevin Torres
2002 Annual Conference Proceedings
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2002 Annual Conference Proceedings
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2000 Annual Conference Proceedings
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First EAGE Reservoir Characterization and Modelling Workflows for Giant Carbonate Field Developments of the Middle East
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The Journal of Supercritical Fluids
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Communications in Computer and Information Science
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Nature immunology, 2018
Although neutrophils have been linked to the formation of the pre-metastatic niche, the mechanism... more Although neutrophils have been linked to the formation of the pre-metastatic niche, the mechanism of their migration to distant, uninvolved tissues has remained elusive. We report that bone marrow neutrophils from mice with early-stage cancer exhibited much more spontaneous migration than that of control neutrophils from tumor-free mice. These cells lacked immunosuppressive activity but had elevated rates of oxidative phosphorylation and glycolysis, and increased production of ATP, relative to that of control neutrophils. Their enhanced spontaneous migration was mediated by autocrine ATP signaling through purinergic receptors. In ectopic tumor models and late stages of cancer, bone marrow neutrophils demonstrated potent immunosuppressive activity. However, these cells had metabolic and migratory activity indistinguishable from that of control neutrophils. A similar pattern of migration was observed for neutrophils and polymorphonuclear myeloid-derived suppressor cells from patients ...
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Nature communications, Dec 14, 2017
Cross-presentation is a critical function of dendritic cells (DCs) required for induction of anti... more Cross-presentation is a critical function of dendritic cells (DCs) required for induction of antitumor immune responses and success of cancer immunotherapy. It is established that tumor-associated DCs are defective in their ability to cross-present antigens. However, the mechanisms driving these defects are still unknown. We find that impaired cross-presentation in DCs is largely associated with defect in trafficking of peptide-MHC class I (pMHC) complexes to the cell surface. DCs in tumor-bearing hosts accumulate lipid bodies (LB) containing electrophilic oxidatively truncated (ox-tr) lipids. These ox-tr-LB, but not LB present in control DCs, covalently bind to chaperone heat shock protein 70. This interaction prevents the translocation of pMHC to cell surface by causing the accumulation of pMHC inside late endosomes/lysosomes. As a result, tumor-associated DCs are no longer able to stimulate adequate CD8 T cells responses. In conclusion, this study demonstrates a mechanism regulat...
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The Journal of Chemical Physics
The crystalline materials with nonlinear optical (NLO) properties are critically important for se... more The crystalline materials with nonlinear optical (NLO) properties are critically important for several technological applications, including nanophotonic and second harmonic generation devices. Urea is often considered to be a standard NLO material, due to the combination of non-centrosymmetric crystal packing and capacity for intramolecular charge transfer. Various approaches to crystal engineering of non-centrosymmetric molecular materials were reported in the literature. Here we propose using global lattice energy minimization to predict the crystal packing from the first principles. We developed a methodology that includes the following: (1) parameter derivation for polarizable force field AMOEBA; (2) local minimizations of crystal structures with these parameters, combined with the evolutionary algorithm for a global minimum search, implemented in program USPEX; (3) filtering out duplicate polymorphs produced; (4) reoptimization and final ranking based on density functional theory (DFT) with many-body dispersion (MBD) correction; and (5) prediction of the second-order susceptibility tensor by finite field approach. This methodology was applied to predict virtual urea polymorphs. After filtering based on packing similarity, only two distinct packing modes were predicted: one experimental and one hypothetical. DFT + MBD ranking established non-centrosymmetric crystal packing as the global minimum, in agreement with the experiment. Finite field approach was used to predict nonlinear susceptibility, and H-bonding was found to account for a 2.5-fold increase in molecular hyperpolarizability to the bulk value.
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Science Immunology, 2016
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International Petroleum Technology Conference, 2014
Formation heterogeneity due to fractures, vugs, and mixed lithologies complicates the characteriz... more Formation heterogeneity due to fractures, vugs, and mixed lithologies complicates the characterization of carbonate reservoirs. The lithology distribution is controlled by multiple factors, such as sediment source, depositional environment, and diagenesis. In addition, fracture development is influenced by lithology, burial depth, local structure, and far-field stress. High-resolution sequence stratigraphy is one of the advanced methods that can be used to solve the lithology challenge. The method combines core analysis, conventional logs, outcrop studies, and seismic data. However, the analysis results are frequently constrained by the low resolution of the seismic and conventional log data and by limited core data. A new workflow for high-resolution sequence stratigraphy analysis integrates borehole resistivity images with seismic, log, and core data. First, the borehole resistivity images are compared with core data, and the depositional facies are identified from calibrated resistivity image data combined with multiple-domain data. Second, sequence stratigraphic surfaces are identified from seismic and image data and the thicknesses of crossbedding and sequence cycles are used to classify the strata stacking patterns. Finally, the distribution of depositional environments within a sequence stratigraphy framework is analyzed by integrating the sequence stratigraphy patterns with seismic attribute maps and petrophysical log interpretation to predict the sweet spot. This new approach was implemented in Block A8 of the Tazhong uplift in the Tarim basin. Six different depositional facies were identified from the core data from three wells and applied to an additional four wells and to noncored intervals. Isopach maps of the first long term sequence cycle were used to estimate the size of buildups (reef, mound) and predict the vug distribution. A recently drilled well confirmed the analysis results. This workflow can be applied to similar thick carbonate reservoirs in the shoal-reef margin of a carbonate platform. Introduction The Tarim basin has three main belts: the Mesozoic and Cenozoic foreland, the Tabei uplift, and the Tazhong uplift (Xianming Xiao et al. 2004). The Tazhong uplift, which has an area of 30 000 km2 is the most complex and difficult area for exploration. The Tazhong-1 slope-break zone extends 200 km from east to west adjacent to a major thrust fault zone in Lower to Upper Ordovician carbonate rocks. Much of the oil and gas discovered in the area occurs in the Upper Ordovician Lianglitage formation. A complex shelf depositional system developed during deposition of the Lianglitage formation. At the same time, the continental shelf margin subfacies along the Tazhong I faulted slope-break zone was developed, and high-energy reef, shoal, and mound facies developed. Within the Tazhong shelf, tidal flat, gently sloping shelf shoal, shelf wash, and mound subfacies developed. The study area, block A8, is located in the western part of the Tazhong I slope break. The first well was drilled in 2005. Eight wells have been drilled, and three of these show good production (Fig. 1). One more appraisal well was recently drilled.
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Proceedings. IEEE SoutheastCon 2001 (Cat. No.01CH37208), 2001
Abstract This paper presents a simple method for the microcontroller implementation of a noninver... more Abstract This paper presents a simple method for the microcontroller implementation of a noninverting buck-boost converter. The converter requires two switches, but only one set of controls. As compared to a cascaded buck converter/boost converter topology, the ...
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2006 IEEE Autotestcon, 2006
Electronic warfare support (ES) systems receive and process RF data real-time and these systems a... more Electronic warfare support (ES) systems receive and process RF data real-time and these systems are time critical. Hardware and software updates to existing ES systems are required to properly maintain these systems. Testing the hardware and software updates plays an important role for releasing the update into the field. The majority of this testing takes place in the laboratory. Two
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SPE Latin American and Caribbean Petroleum Engineering Conference, 2010
Abstract Block X, located in the Talara Basin in northwest Peru, is one of the oldest producing b... more Abstract Block X, located in the Talara Basin in northwest Peru, is one of the oldest producing basins in America. The reservoirs that have been studied are the Eocene Mogollon, Ostrea, Echinocyamus, and Helico units. The present structural model has ...
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International Journal of Public Administration, 2004
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Environmental Toxicology and Chemistry, 2001
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Environmental Toxicology and Chemistry, 2001
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2002 Annual Conference Proceedings
Bookmarks Related papers MentionsView impact
2002 Annual Conference Proceedings
Bookmarks Related papers MentionsView impact
2000 Annual Conference Proceedings
Bookmarks Related papers MentionsView impact
First EAGE Reservoir Characterization and Modelling Workflows for Giant Carbonate Field Developments of the Middle East
Bookmarks Related papers MentionsView impact
The Journal of Supercritical Fluids
Bookmarks Related papers MentionsView impact
Communications in Computer and Information Science
Bookmarks Related papers MentionsView impact
Nature immunology, 2018
Although neutrophils have been linked to the formation of the pre-metastatic niche, the mechanism... more Although neutrophils have been linked to the formation of the pre-metastatic niche, the mechanism of their migration to distant, uninvolved tissues has remained elusive. We report that bone marrow neutrophils from mice with early-stage cancer exhibited much more spontaneous migration than that of control neutrophils from tumor-free mice. These cells lacked immunosuppressive activity but had elevated rates of oxidative phosphorylation and glycolysis, and increased production of ATP, relative to that of control neutrophils. Their enhanced spontaneous migration was mediated by autocrine ATP signaling through purinergic receptors. In ectopic tumor models and late stages of cancer, bone marrow neutrophils demonstrated potent immunosuppressive activity. However, these cells had metabolic and migratory activity indistinguishable from that of control neutrophils. A similar pattern of migration was observed for neutrophils and polymorphonuclear myeloid-derived suppressor cells from patients ...
Bookmarks Related papers MentionsView impact
Nature communications, Dec 14, 2017
Cross-presentation is a critical function of dendritic cells (DCs) required for induction of anti... more Cross-presentation is a critical function of dendritic cells (DCs) required for induction of antitumor immune responses and success of cancer immunotherapy. It is established that tumor-associated DCs are defective in their ability to cross-present antigens. However, the mechanisms driving these defects are still unknown. We find that impaired cross-presentation in DCs is largely associated with defect in trafficking of peptide-MHC class I (pMHC) complexes to the cell surface. DCs in tumor-bearing hosts accumulate lipid bodies (LB) containing electrophilic oxidatively truncated (ox-tr) lipids. These ox-tr-LB, but not LB present in control DCs, covalently bind to chaperone heat shock protein 70. This interaction prevents the translocation of pMHC to cell surface by causing the accumulation of pMHC inside late endosomes/lysosomes. As a result, tumor-associated DCs are no longer able to stimulate adequate CD8 T cells responses. In conclusion, this study demonstrates a mechanism regulat...
Bookmarks Related papers MentionsView impact
The Journal of Chemical Physics
The crystalline materials with nonlinear optical (NLO) properties are critically important for se... more The crystalline materials with nonlinear optical (NLO) properties are critically important for several technological applications, including nanophotonic and second harmonic generation devices. Urea is often considered to be a standard NLO material, due to the combination of non-centrosymmetric crystal packing and capacity for intramolecular charge transfer. Various approaches to crystal engineering of non-centrosymmetric molecular materials were reported in the literature. Here we propose using global lattice energy minimization to predict the crystal packing from the first principles. We developed a methodology that includes the following: (1) parameter derivation for polarizable force field AMOEBA; (2) local minimizations of crystal structures with these parameters, combined with the evolutionary algorithm for a global minimum search, implemented in program USPEX; (3) filtering out duplicate polymorphs produced; (4) reoptimization and final ranking based on density functional theory (DFT) with many-body dispersion (MBD) correction; and (5) prediction of the second-order susceptibility tensor by finite field approach. This methodology was applied to predict virtual urea polymorphs. After filtering based on packing similarity, only two distinct packing modes were predicted: one experimental and one hypothetical. DFT + MBD ranking established non-centrosymmetric crystal packing as the global minimum, in agreement with the experiment. Finite field approach was used to predict nonlinear susceptibility, and H-bonding was found to account for a 2.5-fold increase in molecular hyperpolarizability to the bulk value.
Bookmarks Related papers MentionsView impact
Science Immunology, 2016
Bookmarks Related papers MentionsView impact
Bookmarks Related papers MentionsView impact
Bookmarks Related papers MentionsView impact
International Petroleum Technology Conference, 2014
Formation heterogeneity due to fractures, vugs, and mixed lithologies complicates the characteriz... more Formation heterogeneity due to fractures, vugs, and mixed lithologies complicates the characterization of carbonate reservoirs. The lithology distribution is controlled by multiple factors, such as sediment source, depositional environment, and diagenesis. In addition, fracture development is influenced by lithology, burial depth, local structure, and far-field stress. High-resolution sequence stratigraphy is one of the advanced methods that can be used to solve the lithology challenge. The method combines core analysis, conventional logs, outcrop studies, and seismic data. However, the analysis results are frequently constrained by the low resolution of the seismic and conventional log data and by limited core data. A new workflow for high-resolution sequence stratigraphy analysis integrates borehole resistivity images with seismic, log, and core data. First, the borehole resistivity images are compared with core data, and the depositional facies are identified from calibrated resistivity image data combined with multiple-domain data. Second, sequence stratigraphic surfaces are identified from seismic and image data and the thicknesses of crossbedding and sequence cycles are used to classify the strata stacking patterns. Finally, the distribution of depositional environments within a sequence stratigraphy framework is analyzed by integrating the sequence stratigraphy patterns with seismic attribute maps and petrophysical log interpretation to predict the sweet spot. This new approach was implemented in Block A8 of the Tazhong uplift in the Tarim basin. Six different depositional facies were identified from the core data from three wells and applied to an additional four wells and to noncored intervals. Isopach maps of the first long term sequence cycle were used to estimate the size of buildups (reef, mound) and predict the vug distribution. A recently drilled well confirmed the analysis results. This workflow can be applied to similar thick carbonate reservoirs in the shoal-reef margin of a carbonate platform. Introduction The Tarim basin has three main belts: the Mesozoic and Cenozoic foreland, the Tabei uplift, and the Tazhong uplift (Xianming Xiao et al. 2004). The Tazhong uplift, which has an area of 30 000 km2 is the most complex and difficult area for exploration. The Tazhong-1 slope-break zone extends 200 km from east to west adjacent to a major thrust fault zone in Lower to Upper Ordovician carbonate rocks. Much of the oil and gas discovered in the area occurs in the Upper Ordovician Lianglitage formation. A complex shelf depositional system developed during deposition of the Lianglitage formation. At the same time, the continental shelf margin subfacies along the Tazhong I faulted slope-break zone was developed, and high-energy reef, shoal, and mound facies developed. Within the Tazhong shelf, tidal flat, gently sloping shelf shoal, shelf wash, and mound subfacies developed. The study area, block A8, is located in the western part of the Tazhong I slope break. The first well was drilled in 2005. Eight wells have been drilled, and three of these show good production (Fig. 1). One more appraisal well was recently drilled.
Bookmarks Related papers MentionsView impact
Proceedings. IEEE SoutheastCon 2001 (Cat. No.01CH37208), 2001
Abstract This paper presents a simple method for the microcontroller implementation of a noninver... more Abstract This paper presents a simple method for the microcontroller implementation of a noninverting buck-boost converter. The converter requires two switches, but only one set of controls. As compared to a cascaded buck converter/boost converter topology, the ...
Bookmarks Related papers MentionsView impact
2006 IEEE Autotestcon, 2006
Electronic warfare support (ES) systems receive and process RF data real-time and these systems a... more Electronic warfare support (ES) systems receive and process RF data real-time and these systems are time critical. Hardware and software updates to existing ES systems are required to properly maintain these systems. Testing the hardware and software updates plays an important role for releasing the update into the field. The majority of this testing takes place in the laboratory. Two
Bookmarks Related papers MentionsView impact
SPE Latin American and Caribbean Petroleum Engineering Conference, 2010
Abstract Block X, located in the Talara Basin in northwest Peru, is one of the oldest producing b... more Abstract Block X, located in the Talara Basin in northwest Peru, is one of the oldest producing basins in America. The reservoirs that have been studied are the Eocene Mogollon, Ostrea, Echinocyamus, and Helico units. The present structural model has ...
Bookmarks Related papers MentionsView impact
International Journal of Public Administration, 2004
Bookmarks Related papers MentionsView impact
Environmental Toxicology and Chemistry, 2001
Bookmarks Related papers MentionsView impact
Environmental Toxicology and Chemistry, 2001
Bookmarks Related papers MentionsView impact
Bookmarks Related papers MentionsView impact