Many eukaryotic proteins have been successfully expressed in insect cells infected with a recombi... more Many eukaryotic proteins have been successfully expressed in insect cells infected with a recombinant baculovirus derived from the Autographa californica nuclear polyhedrosis virus (AcNPV). There are, however, disadvantages with this cell-based system when carried out in suspension cultures at high bioreactor volume (e.g., limited oxygen transfer, susceptibility to contamination, high cost). These problems can be avoided by using whole larvae as the ''reactors.'' There are, however, other problems encountered with larvae, one being their inaccessibility for product sampling. To combat this problem, we have investigated the expression of green fluorescent protein (GFP) as a reporter molecule in Trichoplusia ni insect larvae. A high production level of GFPuv (1.58 mg per larva, 26% of total protein) was obtained, enabling the rapid and non-invasive monitoring of GFP. Bright green light was emitted directly from the large opaque carcasses (∼30mm) after illumination with UV light. Based on the green light intensity and a correlation between intensity and GFP mass, we determined the optimal harvest time (c.a. ∼ 3 days post-infection). In parallel experiments, we expressed human interleukin-2 (IL-2) from another recombinant baculovirus with an almost identical expression profile. Since both GFP and IL-2 were rapidly degraded by protease activity during the fourth day post-infection (another disadvantage with larvae), we found an accurate determination of harvest time was critical. Correspondingly, our results demonstrated that GFP was an effective on-line marker for expression of heterologous protein in insect larvae.
An environmentally benign method for the mineralization of sulfur mustard has been proposed invol... more An environmentally benign method for the mineralization of sulfur mustard has been proposed involving chemical hydrolysis of sulfur mustard to thiodiglycol, and then the biological degradation of thiodiglycol to generate biomass and gaseous carbon dioxide.Alcaligenes xylosoxidans (SH91) was isolated based on its ability to utilize thiodiglycol as a sole carbon source. This article compares different biological reactor designs and experimentally assesses their relative effectiveness in degrading thiodiglycol using pure cultures of SH91. The reactor configurations studied are batch, continuous stirred-tank reactor (CSTR), and CSTR with cell recycle. From the results, it is clear that the CSTR with cell recycle offers superior performance for a given residence time or volume. These pure culture data are necessary for accurate design of a pilot-scale system where mixed cultures will be employed because of a possible incomplete chemical hydrolysis step.
Many eukaryotic proteins have been successfully expressed in insect cells infected with a baculov... more Many eukaryotic proteins have been successfully expressed in insect cells infected with a baculovirus in which the foreign gene has been placed under the control of a viral promoter. This system can be costly at large scale due to the quality of virus stock, problems of oxygen transfer, and severity of large-scale contamination. To circumvent this problem, we have investigated the expression of a foreign protein, human interleukin-2 (IL-2), in insect larvae, Trichoplusia ni, infected with the baculovirus Autographa californica nuclear polyhedrosis virus (AcNPV). The IL-2 gene was placed under control of the p10 promoter so that the polyhedra remained intact for efficient primary infection. From our results, it was clear that early infection limited larval growth and late infection delayed product production until near pupation, hence infection timing was important. Also, the harvest time was crucial for obtaining high yield, because IL-2 production had a sharp optimal peak with a time of occurrence dependent on both temperature and the initial amount of infection virus. Specifically, we found that, by raising the infection temperature to 30°C, we more than doubled the protein productivity. Furthermore, a significant concern of the larvae/baculovirus expression system has been the large amount of protease produced by the larvae, which adversely affects the protein yield. Therefore, we screened several protease inhibitors and characterized the larval protease specificity and timing to attenuate their impact. This report elucidates and delineates the factors that most directly impact protein yield in the larvae expression system, using IL-2 as a model.
The insect larvae/baculovirus protein production process was dramatically simplified by expressin... more The insect larvae/baculovirus protein production process was dramatically simplified by expressing fusion proteins containing green fluorescent protein (GFP) and the product-of-interest. In this case, human interleukin-2 (hIL-2) and chloramphenicol acetyl-transferase (CAT) were model products. Specifically, our fusion construct was comprised of a histidine affinity ligand for simplified purification using immobilized metal affinity chromatography (IMAC), the UV-optimized GFP (GFPuv) as a marker, an enterokinase cleavage site for recovery of the product from the fusion, and the product, hIL-2 or CAT. Both the approximately 52 kDa GFPuv/hIL-2 and approximately 63 kDa GFPuv/CAT fusions were expressed in Trichoplusia ni larvae at 9.0 microg-hIL-2 and 24.1 microg-CAT per larva, respectively. The GFP enabled clear identification of the infection process, harvest time, and more importantly, the quantity of product protein. Because the GFP served as a marker, this technique obviates the need for in-process Western analyses (during expression, separation, and purification stages). As a purification marker, GFP facilitated rapid identification of product-containing elution fractions (Cha et al., 1999b), as well as product-containing waste fractions (e.g., cell pellet). Also, because the fluorescence intensity was linear with hIL-2 and CAT, we were able to select the highest-producing larvae. That is, three fold more product was found in the brightest larva compared to the average. Finally, because the GFP is attached to the product protein and the producing larvae can be selected, the infection and production processes can be made semi-continuous or continuous, replacing the current batch process. These advantages should help to enable commercialization of larvae as expression hosts.
Ce:LuLiF 4 is evaluated as a fast scintillator using a storage ring free-electron laser operating... more Ce:LuLiF 4 is evaluated as a fast scintillator using a storage ring free-electron laser operating in the deep-ultraviolet region. The relatively flat spectral response across its absorption bands makes this material an attractive scintillator for various excitation sources. Its decay time is acceptable for ignition timing in fast-ignition, inertial confinement nuclear fusion using laser. This report is the first systematic study on Ce:LuLiF 4 as a scintillator, wherein the storage ring free-electron laser is also shown as a powerful tool for material survey.
We propose an efficient side-pumping scheme for ultraviolet (UV) femtosecond pulse amplification ... more We propose an efficient side-pumping scheme for ultraviolet (UV) femtosecond pulse amplification in micro-pulling-down (цPD) method-grown Ce:LiCAF using a prismatic cell-type configuration. By uniformly illuminating four sides of a 2-mm-diameter and 30-mm-length ...
Details of the design and development of a bright vacuum ultraviolet Seya-Namioka type spectromet... more Details of the design and development of a bright vacuum ultraviolet Seya-Namioka type spectrometer and streak camera system with reflection-type input optics is presented. The Seya-Namioka spectrometer has a 40 mm by 45 mm holographic grating with a groove density of 600 grooves/mm, linear dispersion of 8 nm/mm, and effective F -number of 4.2. To eliminate loss of light by absorption, the streak camera imaging unit uses Al and MgF 2 coated imaging optics with at least 80% reflection from 125 -850 nm and has an effective Fnumber of 4. It is equipped with a synchronized scan unit that can be tuned to 82 MHz and a slow scan speed unit that can measure up to 2-MHz single event. Temporal response of the system at the 20-ns scanning range is evaluated to be around 260 ps.
Pergamon Electrochimica Ada. Vol. 42, No. 3, pp. 439447, 1997 Copyright 1996 Elsevier Science Ltd... more Pergamon Electrochimica Ada. Vol. 42, No. 3, pp. 439447, 1997 Copyright 1996 Elsevier Science Ltd. Printed in Great Britain. All rights reserved PII: 800134(86(96)002393 0013686 97 17.00 + 0.00 Study of a heteropolyaniondoped poly(5aminolnaphthol) film electrode and its ...
2013 16th International Conference on Advanced Robotics (ICAR), 2013
This paper presents the modeling of a pneumatic system devoted to a teleoperation application. Th... more This paper presents the modeling of a pneumatic system devoted to a teleoperation application. The study deals with the specific problem of the additional dynamics introduced by the air hose length when the servovalves are located far from the pneumatic cylinder. The physical modeling of each component of the system leads to either a set of nonlinear ordinary differential equations (ODEs) or a set of nonlinear partial differential equations (PDEs). We show that a classical expansion around a working point provides a model consisting of a finite set of ODEs. A second aspect of this work relates to the use of this model within a bilateral teleoperation scheme. In order to design a two-channel teleoperation controller, a model reduction is required. Simulation results show the efficiency of our approach in terms of both robustness with respect to modeling errors and transparency, whether in free space or in contact motion.
2011 IEEE/RSJ International Conference on Intelligent Robots and Systems, 2011
This paper proposes a sliding mode law for precise position control with minimal switching activi... more This paper proposes a sliding mode law for precise position control with minimal switching activity for a robotic system that uses on/off (solenoid) pneumatic actuators, For a two-chamber pneumatic actuator with four binary solenoid valves, there is a total of sixteen possible input combinations defined directly from the state of the four on/off solenoid valves present in the system. However, only seven of these discrete operating modes are considered both functional and unique. Accordingly, we use a seven-mode sliding controller that minimizes the position error using modes that have both the necessary and sufficient amounts of drive energy and, thus, involve reduced switching activity. An analysis of the closedloop system stability is carried out. The performance of the proposed control design is experimentally verified on a single pneumatic actuator comprising of two chambers driven by four on/off solenoid valves.
It is argued that without collateral the poor often face binding borrowing constraints in the for... more It is argued that without collateral the poor often face binding borrowing constraints in the formal credit market. This justifies a micro-credit program, which is operated by the Vietnam Bank for Social Policies to provide the poor with preferential credit. This paper examines poverty targeting and impact of the micro-credit program. It is found that the program is not very pro-poor in terms of targeting. Among the participants, the non-poor account for a larger proportion of loans. The non-poor also tend to receive larger amounts of credit compared to the poor. However, the program has positive impact on poverty reduction of the participants. This positive impact is found for all the three Foster-Greer-Thorbecke poverty measures.
In fields of classification and clustering of patterns most conventional methods of feature extra... more In fields of classification and clustering of patterns most conventional methods of feature extraction do not pay much attention to the geometric properties of data, even in cases where the data have spatial features. This paper proposes to use geometric algebra to systematically extract geometric features from data given as a series or a set of vectors in a vector space. We show the results of classification of hand-written digits and those of clustering of consumers' impression with the proposed method.
We propose a high speed non-empirical method to detect centers of tropical cyclones, which is use... more We propose a high speed non-empirical method to detect centers of tropical cyclones, which is useful to identify tropical cyclones in huge climatology data. In this method, centers of tropical cyclones are detected automatically by iteration of streamline in down-stream direction from some initial positions. We also bend the path of streamline successively to converge on the center of tropical
International Conference on Robotics and Automation, 2007
Abstract Today, medical simulators are increasingly gaining attraction in clinical settings. Thes... more Abstract Today, medical simulators are increasingly gaining attraction in clinical settings. These tools allow physicians to visualize the positions of organs, plan surgical interventions, and carry out more comprehensive post operative monitoring. A childbirth simulator ...
International Conference on Robotics and Automation, 2001
Proposes a method to identify the joint stiffness of a robot using a bandpass filter. It is based... more Proposes a method to identify the joint stiffness of a robot using a bandpass filter. It is based on moving one axis at a time. The dynamic model reduces to a model which is linear in relation to a minimum set of dynamical parameters which have to be identified. These parameters are estimated using the least squares solution of an over determined linear system obtained from the sampling of the dynamic model along a closed loop tracking trajectory. Conditions for a good data processing before identification are exhibited through practical aspects concerning data sampling and data filtering. An experimental study shows the efficiency of the method with two sets of data depending on motor joint position measurements.
Today, medical simulators are increasingly gaining appeal in clinical settings. In obstetrics chi... more Today, medical simulators are increasingly gaining appeal in clinical settings. In obstetrics childbirth simulators provide a training and research tool for comparing various techniques that use obstetrical instruments or validating new methods. Especially in the case of difficult deliveries, the use of obstetrical instruments-such as forceps, spatulas, and vacuum extractors-has become essential. However, such instruments increase the risk of injury to both the mother and fetus. Only clinical experience acquired in the delivery room enables health professionals to reduce this risk. In this context, we have developed, in collaboration with researchers and physicians, a new type of instrumented forceps that offers new solutions for training obstetricians in the safe performance of forceps deliveries. This paper focuses on the design of this instrumented forceps, coupled with the BirthSIM simulator. This instrumented forceps allows to study its displacement inside the maternal pelvis. Methods for analyzing the operator repeatability and to compare forceps blade placements to a reference one are developed. The results highlight the need of teaching tools to adequately train novice obstetricians.
American Journal of Obstetrics and Gynecology, 2006
Objective: The purpose of this study was to create a new instrument for the training of doctors i... more Objective: The purpose of this study was to create a new instrument for the training of doctors in the use of forceps and to compare the trajectories of forceps blades between junior and senior obstetricians. Study design: We equipped a simulator and forceps with spatial location sensors. The head of the fetus was in an occipitoanterior location, at a ''C5'' station. Forceps blade trajectories were analyzed subjectively with the 3-dimensional spatial graph and objectively based on 3 points of special interest. Each obstetrician performed 4 forceps blades placements. We compared the trajectories of junior and senior obstetricians. Results: For senior operators, spatial dispersion was ''excellent,'' ''very good,'' or ''good'' in 92% of cases, whereas this was the case for only 38% of junior doctors (92% vs 38%; P ! .001). Conclusion: A new instrument has been designed to demonstrate the trajectory of forceps blades during application in a simulator. The instrument captures the difference in experience between senior and junior clinicians.
As part of a feminist commitment to collaboration, this article appears as a companion essay to M... more As part of a feminist commitment to collaboration, this article appears as a companion essay to Mimi Thi Nguyen's "The Biopower of Beauty: Humanitarian Imperialisms and Global Feminisms" and offers a point of departure for thinking about fashion and beauty as processes that produce subjects recruited to, and aligned with, the national interests of the United States in the war on terror. The Muslim woman in the veil and her imagined opposite in the fashionably modern - and implicitly Western - woman become convenient metaphors for articulating geopolitical contests of power as a human rights concern, as a rescue mission, as a beautifying mandate. This article examines newer iterations of this opposition, in the wake of September 11, 2001, in order to demonstrate the critical resonance of a biopolitics on fashion and beauty. In "The Right to Fashion in the Age of Terrorism," the author examines the relationship between the U.S. war on terror, targeting persons whose sartorial choices are described as terrorist-looking and oppressive, and the right-to-fashion discourse, which promotes fashion's mass-market diffusion as a civil liberty. Looking at these multiple invocations of the democratization of fashion, this article argues that the right-to-fashion discourse colludes with the war on terror by fabricating a neoliberal consumer-citizen who is also a couture-citizen and whose right to fashion reasserts U.S.exceptionalism, which is secured by private property, social mobility, and individualism.
Many eukaryotic proteins have been successfully expressed in insect cells infected with a recombi... more Many eukaryotic proteins have been successfully expressed in insect cells infected with a recombinant baculovirus derived from the Autographa californica nuclear polyhedrosis virus (AcNPV). There are, however, disadvantages with this cell-based system when carried out in suspension cultures at high bioreactor volume (e.g., limited oxygen transfer, susceptibility to contamination, high cost). These problems can be avoided by using whole larvae as the ''reactors.'' There are, however, other problems encountered with larvae, one being their inaccessibility for product sampling. To combat this problem, we have investigated the expression of green fluorescent protein (GFP) as a reporter molecule in Trichoplusia ni insect larvae. A high production level of GFPuv (1.58 mg per larva, 26% of total protein) was obtained, enabling the rapid and non-invasive monitoring of GFP. Bright green light was emitted directly from the large opaque carcasses (∼30mm) after illumination with UV light. Based on the green light intensity and a correlation between intensity and GFP mass, we determined the optimal harvest time (c.a. ∼ 3 days post-infection). In parallel experiments, we expressed human interleukin-2 (IL-2) from another recombinant baculovirus with an almost identical expression profile. Since both GFP and IL-2 were rapidly degraded by protease activity during the fourth day post-infection (another disadvantage with larvae), we found an accurate determination of harvest time was critical. Correspondingly, our results demonstrated that GFP was an effective on-line marker for expression of heterologous protein in insect larvae.
An environmentally benign method for the mineralization of sulfur mustard has been proposed invol... more An environmentally benign method for the mineralization of sulfur mustard has been proposed involving chemical hydrolysis of sulfur mustard to thiodiglycol, and then the biological degradation of thiodiglycol to generate biomass and gaseous carbon dioxide.Alcaligenes xylosoxidans (SH91) was isolated based on its ability to utilize thiodiglycol as a sole carbon source. This article compares different biological reactor designs and experimentally assesses their relative effectiveness in degrading thiodiglycol using pure cultures of SH91. The reactor configurations studied are batch, continuous stirred-tank reactor (CSTR), and CSTR with cell recycle. From the results, it is clear that the CSTR with cell recycle offers superior performance for a given residence time or volume. These pure culture data are necessary for accurate design of a pilot-scale system where mixed cultures will be employed because of a possible incomplete chemical hydrolysis step.
Many eukaryotic proteins have been successfully expressed in insect cells infected with a baculov... more Many eukaryotic proteins have been successfully expressed in insect cells infected with a baculovirus in which the foreign gene has been placed under the control of a viral promoter. This system can be costly at large scale due to the quality of virus stock, problems of oxygen transfer, and severity of large-scale contamination. To circumvent this problem, we have investigated the expression of a foreign protein, human interleukin-2 (IL-2), in insect larvae, Trichoplusia ni, infected with the baculovirus Autographa californica nuclear polyhedrosis virus (AcNPV). The IL-2 gene was placed under control of the p10 promoter so that the polyhedra remained intact for efficient primary infection. From our results, it was clear that early infection limited larval growth and late infection delayed product production until near pupation, hence infection timing was important. Also, the harvest time was crucial for obtaining high yield, because IL-2 production had a sharp optimal peak with a time of occurrence dependent on both temperature and the initial amount of infection virus. Specifically, we found that, by raising the infection temperature to 30°C, we more than doubled the protein productivity. Furthermore, a significant concern of the larvae/baculovirus expression system has been the large amount of protease produced by the larvae, which adversely affects the protein yield. Therefore, we screened several protease inhibitors and characterized the larval protease specificity and timing to attenuate their impact. This report elucidates and delineates the factors that most directly impact protein yield in the larvae expression system, using IL-2 as a model.
The insect larvae/baculovirus protein production process was dramatically simplified by expressin... more The insect larvae/baculovirus protein production process was dramatically simplified by expressing fusion proteins containing green fluorescent protein (GFP) and the product-of-interest. In this case, human interleukin-2 (hIL-2) and chloramphenicol acetyl-transferase (CAT) were model products. Specifically, our fusion construct was comprised of a histidine affinity ligand for simplified purification using immobilized metal affinity chromatography (IMAC), the UV-optimized GFP (GFPuv) as a marker, an enterokinase cleavage site for recovery of the product from the fusion, and the product, hIL-2 or CAT. Both the approximately 52 kDa GFPuv/hIL-2 and approximately 63 kDa GFPuv/CAT fusions were expressed in Trichoplusia ni larvae at 9.0 microg-hIL-2 and 24.1 microg-CAT per larva, respectively. The GFP enabled clear identification of the infection process, harvest time, and more importantly, the quantity of product protein. Because the GFP served as a marker, this technique obviates the need for in-process Western analyses (during expression, separation, and purification stages). As a purification marker, GFP facilitated rapid identification of product-containing elution fractions (Cha et al., 1999b), as well as product-containing waste fractions (e.g., cell pellet). Also, because the fluorescence intensity was linear with hIL-2 and CAT, we were able to select the highest-producing larvae. That is, three fold more product was found in the brightest larva compared to the average. Finally, because the GFP is attached to the product protein and the producing larvae can be selected, the infection and production processes can be made semi-continuous or continuous, replacing the current batch process. These advantages should help to enable commercialization of larvae as expression hosts.
Ce:LuLiF 4 is evaluated as a fast scintillator using a storage ring free-electron laser operating... more Ce:LuLiF 4 is evaluated as a fast scintillator using a storage ring free-electron laser operating in the deep-ultraviolet region. The relatively flat spectral response across its absorption bands makes this material an attractive scintillator for various excitation sources. Its decay time is acceptable for ignition timing in fast-ignition, inertial confinement nuclear fusion using laser. This report is the first systematic study on Ce:LuLiF 4 as a scintillator, wherein the storage ring free-electron laser is also shown as a powerful tool for material survey.
We propose an efficient side-pumping scheme for ultraviolet (UV) femtosecond pulse amplification ... more We propose an efficient side-pumping scheme for ultraviolet (UV) femtosecond pulse amplification in micro-pulling-down (цPD) method-grown Ce:LiCAF using a prismatic cell-type configuration. By uniformly illuminating four sides of a 2-mm-diameter and 30-mm-length ...
Details of the design and development of a bright vacuum ultraviolet Seya-Namioka type spectromet... more Details of the design and development of a bright vacuum ultraviolet Seya-Namioka type spectrometer and streak camera system with reflection-type input optics is presented. The Seya-Namioka spectrometer has a 40 mm by 45 mm holographic grating with a groove density of 600 grooves/mm, linear dispersion of 8 nm/mm, and effective F -number of 4.2. To eliminate loss of light by absorption, the streak camera imaging unit uses Al and MgF 2 coated imaging optics with at least 80% reflection from 125 -850 nm and has an effective Fnumber of 4. It is equipped with a synchronized scan unit that can be tuned to 82 MHz and a slow scan speed unit that can measure up to 2-MHz single event. Temporal response of the system at the 20-ns scanning range is evaluated to be around 260 ps.
Pergamon Electrochimica Ada. Vol. 42, No. 3, pp. 439447, 1997 Copyright 1996 Elsevier Science Ltd... more Pergamon Electrochimica Ada. Vol. 42, No. 3, pp. 439447, 1997 Copyright 1996 Elsevier Science Ltd. Printed in Great Britain. All rights reserved PII: 800134(86(96)002393 0013686 97 17.00 + 0.00 Study of a heteropolyaniondoped poly(5aminolnaphthol) film electrode and its ...
2013 16th International Conference on Advanced Robotics (ICAR), 2013
This paper presents the modeling of a pneumatic system devoted to a teleoperation application. Th... more This paper presents the modeling of a pneumatic system devoted to a teleoperation application. The study deals with the specific problem of the additional dynamics introduced by the air hose length when the servovalves are located far from the pneumatic cylinder. The physical modeling of each component of the system leads to either a set of nonlinear ordinary differential equations (ODEs) or a set of nonlinear partial differential equations (PDEs). We show that a classical expansion around a working point provides a model consisting of a finite set of ODEs. A second aspect of this work relates to the use of this model within a bilateral teleoperation scheme. In order to design a two-channel teleoperation controller, a model reduction is required. Simulation results show the efficiency of our approach in terms of both robustness with respect to modeling errors and transparency, whether in free space or in contact motion.
2011 IEEE/RSJ International Conference on Intelligent Robots and Systems, 2011
This paper proposes a sliding mode law for precise position control with minimal switching activi... more This paper proposes a sliding mode law for precise position control with minimal switching activity for a robotic system that uses on/off (solenoid) pneumatic actuators, For a two-chamber pneumatic actuator with four binary solenoid valves, there is a total of sixteen possible input combinations defined directly from the state of the four on/off solenoid valves present in the system. However, only seven of these discrete operating modes are considered both functional and unique. Accordingly, we use a seven-mode sliding controller that minimizes the position error using modes that have both the necessary and sufficient amounts of drive energy and, thus, involve reduced switching activity. An analysis of the closedloop system stability is carried out. The performance of the proposed control design is experimentally verified on a single pneumatic actuator comprising of two chambers driven by four on/off solenoid valves.
It is argued that without collateral the poor often face binding borrowing constraints in the for... more It is argued that without collateral the poor often face binding borrowing constraints in the formal credit market. This justifies a micro-credit program, which is operated by the Vietnam Bank for Social Policies to provide the poor with preferential credit. This paper examines poverty targeting and impact of the micro-credit program. It is found that the program is not very pro-poor in terms of targeting. Among the participants, the non-poor account for a larger proportion of loans. The non-poor also tend to receive larger amounts of credit compared to the poor. However, the program has positive impact on poverty reduction of the participants. This positive impact is found for all the three Foster-Greer-Thorbecke poverty measures.
In fields of classification and clustering of patterns most conventional methods of feature extra... more In fields of classification and clustering of patterns most conventional methods of feature extraction do not pay much attention to the geometric properties of data, even in cases where the data have spatial features. This paper proposes to use geometric algebra to systematically extract geometric features from data given as a series or a set of vectors in a vector space. We show the results of classification of hand-written digits and those of clustering of consumers' impression with the proposed method.
We propose a high speed non-empirical method to detect centers of tropical cyclones, which is use... more We propose a high speed non-empirical method to detect centers of tropical cyclones, which is useful to identify tropical cyclones in huge climatology data. In this method, centers of tropical cyclones are detected automatically by iteration of streamline in down-stream direction from some initial positions. We also bend the path of streamline successively to converge on the center of tropical
International Conference on Robotics and Automation, 2007
Abstract Today, medical simulators are increasingly gaining attraction in clinical settings. Thes... more Abstract Today, medical simulators are increasingly gaining attraction in clinical settings. These tools allow physicians to visualize the positions of organs, plan surgical interventions, and carry out more comprehensive post operative monitoring. A childbirth simulator ...
International Conference on Robotics and Automation, 2001
Proposes a method to identify the joint stiffness of a robot using a bandpass filter. It is based... more Proposes a method to identify the joint stiffness of a robot using a bandpass filter. It is based on moving one axis at a time. The dynamic model reduces to a model which is linear in relation to a minimum set of dynamical parameters which have to be identified. These parameters are estimated using the least squares solution of an over determined linear system obtained from the sampling of the dynamic model along a closed loop tracking trajectory. Conditions for a good data processing before identification are exhibited through practical aspects concerning data sampling and data filtering. An experimental study shows the efficiency of the method with two sets of data depending on motor joint position measurements.
Today, medical simulators are increasingly gaining appeal in clinical settings. In obstetrics chi... more Today, medical simulators are increasingly gaining appeal in clinical settings. In obstetrics childbirth simulators provide a training and research tool for comparing various techniques that use obstetrical instruments or validating new methods. Especially in the case of difficult deliveries, the use of obstetrical instruments-such as forceps, spatulas, and vacuum extractors-has become essential. However, such instruments increase the risk of injury to both the mother and fetus. Only clinical experience acquired in the delivery room enables health professionals to reduce this risk. In this context, we have developed, in collaboration with researchers and physicians, a new type of instrumented forceps that offers new solutions for training obstetricians in the safe performance of forceps deliveries. This paper focuses on the design of this instrumented forceps, coupled with the BirthSIM simulator. This instrumented forceps allows to study its displacement inside the maternal pelvis. Methods for analyzing the operator repeatability and to compare forceps blade placements to a reference one are developed. The results highlight the need of teaching tools to adequately train novice obstetricians.
American Journal of Obstetrics and Gynecology, 2006
Objective: The purpose of this study was to create a new instrument for the training of doctors i... more Objective: The purpose of this study was to create a new instrument for the training of doctors in the use of forceps and to compare the trajectories of forceps blades between junior and senior obstetricians. Study design: We equipped a simulator and forceps with spatial location sensors. The head of the fetus was in an occipitoanterior location, at a ''C5'' station. Forceps blade trajectories were analyzed subjectively with the 3-dimensional spatial graph and objectively based on 3 points of special interest. Each obstetrician performed 4 forceps blades placements. We compared the trajectories of junior and senior obstetricians. Results: For senior operators, spatial dispersion was ''excellent,'' ''very good,'' or ''good'' in 92% of cases, whereas this was the case for only 38% of junior doctors (92% vs 38%; P ! .001). Conclusion: A new instrument has been designed to demonstrate the trajectory of forceps blades during application in a simulator. The instrument captures the difference in experience between senior and junior clinicians.
As part of a feminist commitment to collaboration, this article appears as a companion essay to M... more As part of a feminist commitment to collaboration, this article appears as a companion essay to Mimi Thi Nguyen's "The Biopower of Beauty: Humanitarian Imperialisms and Global Feminisms" and offers a point of departure for thinking about fashion and beauty as processes that produce subjects recruited to, and aligned with, the national interests of the United States in the war on terror. The Muslim woman in the veil and her imagined opposite in the fashionably modern - and implicitly Western - woman become convenient metaphors for articulating geopolitical contests of power as a human rights concern, as a rescue mission, as a beautifying mandate. This article examines newer iterations of this opposition, in the wake of September 11, 2001, in order to demonstrate the critical resonance of a biopolitics on fashion and beauty. In "The Right to Fashion in the Age of Terrorism," the author examines the relationship between the U.S. war on terror, targeting persons whose sartorial choices are described as terrorist-looking and oppressive, and the right-to-fashion discourse, which promotes fashion's mass-market diffusion as a civil liberty. Looking at these multiple invocations of the democratization of fashion, this article argues that the right-to-fashion discourse colludes with the war on terror by fabricating a neoliberal consumer-citizen who is also a couture-citizen and whose right to fashion reasserts U.S.exceptionalism, which is secured by private property, social mobility, and individualism.
Uploads
Papers by Minh Pham