We report on laser-induced spall experiments aimed at studying how a material&amp... more We report on laser-induced spall experiments aimed at studying how a material's microstructure affects the tensile fracture characteristics at high strain rates (>10^6 s-1). We used the Z-Beamlet Laser at Sandia National Laboratory to drive shocks and to measure the spall strength of aluminum targets with various microstructures. The targets were recrystallized, high-purity aluminum (Al-HP RX), recrystallized aluminum + 3
Principles and Practice of Constraint Programming, 1995
In this paper, we focus on techniques for constraint-based design tasks with continuous variables... more In this paper, we focus on techniques for constraint-based design tasks with continuous variables in dynamic environments. We show how design spaces can be explored within an intelligent CAD system using a dynamic constraint satisfaction framework and a conflict resolution paradigm. Navigation between different design spaces is controlled by assumptions the designer makes in situations of incomplete knowledge. These assumptions
Design tasks in structural engineering have always involved the use of constraints to formulate d... more Design tasks in structural engineering have always involved the use of constraints to formulate design requirements. Most existing algorithms for constraint satisfaction require input consisting of binary constraints on variables that have discrete values. Such restrictions limit their use in structural engineering since typical structural design tasks involve discrete and numerical variables. This paper provides an approach for decision support
We introduce and apply a new classification strategy we call computerized consensus diagnosis (CC... more We introduce and apply a new classification strategy we call computerized consensus diagnosis (CCD). Its purpose is to provide robust, reliable classification of biomedical data. The strategy involves the cross-validated training of seven/ classifiers of diverse conceptual and methodological origin on the same data, and appropriately combining their outcomes. The strategy is tested on proton magnetic resonance spectra of human thyroid biopsies, which are successfully allocated to normal or carcinoma classes. We used Linear Discriminant Analysis, a Neural Net-based method, and Genetic Programming as independent classifiers on two spectral regions, and chose the median of the six classification outcomes as the consensus. This procedure yielded 100% specificity and 100% sensitivity on the training sets, and 100% specificity and 98% sensitivity on samples of known malignancy in the test sets.
Journal of Pharmaceutical and Biomedical Analysis, 2010
Bile acids, phospholipids, and cholesterol are the major lipid components in human bile. The comp... more Bile acids, phospholipids, and cholesterol are the major lipid components in human bile. The composition of bile is altered in various cholestatic diseases, and determining such alterations will be of great clinical importance in understanding the pathophysiology of these diseases. A robust method for the simultaneous quantification of major biliary lipids -glycine-conjugated bile acids (GCBAs), taurine-conjugated bile acids (TCBAs), total bile acids (TBAs) and choline-containing phospholipids (choline-PLs) has been devised using 1 H NMR spectroscopy. Bile samples were obtained from patients with various hepatopancreatobiliary diseases (n = 10) during an endoscopic retrograde cholangiopancreatography (ERCP) examination. Peak areas of metabolite-signals of interest were obtained simultaneously by deconvoluting the experimental spectrum, making the present method robust. GCBAs and TCBAs have been quantified using the peak areas of their characteristic methylene (CH 2 ) signals resonating at 3.73 and 3.07 ppm, whereas TBA and choline-PLs were quantified using their methyl (CH 3 ) and trimethylammonium (-N + (CH 3 ) 3 ) signals resonating at 0.65 and 3.22 ppm respectively. The present method was compared with an NMR-based literature method (which involves dissolving bile in DMSO), and a good correlation was observed between the two methods with regression coefficients -0.97, 0.99, 0.98 and 0.93 for GCBAs, TCBAs, TBAs, and choline-PLs respectively. This method has the potential to be extended to in vivo applications for the simultaneous quantification of various biliary lipids non-invasively.
A unique procedure for the biosynthesis and subsequent isolation of a series of specifically deut... more A unique procedure for the biosynthesis and subsequent isolation of a series of specifically deuteriated cis,cis-octadeca-6,9-dienoic acids has been developed. An auxotroph of Tetrahymena, which lacks ..delta..9 and ..delta..12 desaturase activity, is supplemented with specifically deuteriated oleic acid and converts it to the corresponding deuteriated cis,cis-octadeca-6,9-dienoic acid, 18:2/sup ..delta..6,9/. The deuteriated fatty acid is subsequently isolated by argentation chromatography and
Material microstructure is a significant determinant of the tensile stress at which materials fai... more Material microstructure is a significant determinant of the tensile stress at which materials fail. Using a high-energy laser to drive shocks in thin slabs, we have explored the role material microstructure plays on the spall strength of high-purity and alloyed aluminum at strain rates of (2-7.5)×106 s-1. Slabs of pure recrystallized Al and recrystallized or cold worked Al+3 wt % Mg were shock driven using the Z-Beamlet Laser at Sandia National Laboratories. Velocity interferometer measurements determined the spall strength of the materials, and postshot target analysis explored the microscopic fracture morphology. We observed the greatest spall strength for large-grained, recrystallized high-purity aluminum, with the dominant failure mode being ductile and transgranular. We observe for the first time at these strain rates fracture features for a fine-grained Al+3 wt % Mg that were a combination of brittle intergranular and ductile transgranular fracture types. Postshot analysis of target cross sections and hydrocode simulations indicate that this mixed-mode failure results from spall dynamics occurring on spatial scales on the order of the grain size. Differences in spall strength between these Al samples were experimentally significant and correlate with the damage morphologies observed.
This study examined the effects of 10 days of buthionine sulfoximine (BSO) treatment on in vitro ... more This study examined the effects of 10 days of buthionine sulfoximine (BSO) treatment on in vitro contractility and sarcoplasmic reticulum calcium pump (SERCA) expression and function in adult (AD; 6-8 months old) and middle aged (MA; 14-17 months old) rat diaphragm in both the basal state and following fatiguing stimulation. BSO treatment reduced the cellular concentrations of free glutathione (GSH) by >95% and oxidized glutathione (GSSG) by >80% in both age cohorts. GSH content in AD Control diaphragm was 32% higher (P < 0.01) than in MA Control, with no differences in GSSG. The ratio of GSH:GSSG, an indicator of cellular oxidative state, was 34.6 ± 7.4 in MA Control, 52.5 ± 10.1 in AD Control, 10.6 ± 1.7 in MA BSO, and 9.5 ± 1.1 in AD BSO (BSO vs. Control,…
International Journal for Numerical and Analytical Methods in Geomechanics, 1992
In this note the accuracy of the elastic standard 4-node plane-strain finite element is investiga... more In this note the accuracy of the elastic standard 4-node plane-strain finite element is investigated by comparing numerically calculated eigenvalues of the element stiffness matrix to those according to higherorder algebraic approximations. From this study it may be concluded that the 'hourglass' eigenmodes are the only inaccurate ones. For selective reduced numerical integration the hourglass eigenvalues may be expected to be of the order of 1/2 to 2/3 of the analytical values. *Professor. 'Lecturer. 'Professor.
Ground-based and Airborne Instrumentation for Astronomy III, 2010
SPHERE is a second generation instrument for the Very Large Telescope (VLT) which will aim at dir... more SPHERE is a second generation instrument for the Very Large Telescope (VLT) which will aim at directly detecting the intrinsic flux of young giant exoplanets thanks to a dedicated extreme adaptive optics system and coronagraphs. Exoplanet detection in the near-infrared will be performed in parallel with an integral field spectrograph and a differential imager, IRDIS. IRDIS main mode for exoplanet
ABSTRACT In Part I, eigenvalues and eigenmodes of typical plane element stiffness matrices were s... more ABSTRACT In Part I, eigenvalues and eigenmodes of typical plane element stiffness matrices were separated and traced. This has important implications for the viability of new elements (presence of zero energy modes) and integrability of dynamic equations (critical time steps). In this part of the paper, similar techniques are applied to well-known solid element stiffness matrices, and to some new ones.
Proceedings of the fifth ACM conference on Hypertext - HYPERTEXT '93, 1993
We describe the organization and implementation of the Knowledge Weasel (KW) Hypermedia Annotatio... more We describe the organization and implementation of the Knowledge Weasel (KW) Hypermedia Annotation System which we are using to explore knowledge structuring by collaborative annotation. Knowledge Weasel incorporates many useful features: a common record format for representing annotations in different media for uniform access; dynamic user control of the presentation of annotations as a navigational aid global navigation using queries
Background: The aim was to develop robust classi®ers to analyse magnetic resonance spectroscopy (... more Background: The aim was to develop robust classi®ers to analyse magnetic resonance spectroscopy (MRS) data of ®ne-needle aspirates taken from breast tumours. The resulting data could provide computerized, classi®cation-based diagnosis and prognostic indicators.
Canadian Journal of Physiology and Pharmacology, 2015
In this study, we sought to determine whether differences in cellular properties associated with ... more In this study, we sought to determine whether differences in cellular properties associated with energy homeostasis could explain the higher incidence of work-related myalgia in trapezius (TRAP) compared with extensor carpi radialis brevis (ECRB). Tissue samples were obtained from the ECRB (n = 19) and TRAP (n = 17) of healthy males and females (age 27.9 ± 2.2 and 28.1 ± 1.5 years, respectively; mean ± SE) and analyzed for properties involved in both ATP supply and utilization. The concentration of ATP and the maximal activities of creatine phosphokinase, phosphorylase, and phosphofructokinase were higher (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05) in ECRB than TRAP. Succinic dehydrogenase, citrate synthase, and cytochrome c oxidase were not different between muscles. The ECRB also displayed a higher concentration of Na(+)-K(+)-ATPase and greater sarcoplasmic reticulum Ca(2+) release and uptake. No differences existed between muscles for either monocarboxylate transporters or glucose transporters. It is concluded that the potentials for high-energy phosphate transfer, glycogenolysis, glycolysis, and excitation-contraction coupling are higher in ECRB than TRAP. Histochemical measurements indicated that the muscle differences are, in part, related to differing amounts of type II tissue. Depending on the task demands, the TRAP may experience a greater metabolic and excitation-contraction coupling strain than the ECRB given the differences observed.
We report on laser-induced spall experiments aimed at studying how a material&amp;amp;amp;amp... more We report on laser-induced spall experiments aimed at studying how a material&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s microstructure affects the tensile fracture characteristics at high strain rates (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;10^6 s-1). We used the Z-Beamlet Laser at Sandia National Laboratory to drive shocks and to measure the spall strength of aluminum targets with various microstructures. The targets were recrystallized, high-purity aluminum (Al-HP RX), recrystallized aluminum + 3
Principles and Practice of Constraint Programming, 1995
In this paper, we focus on techniques for constraint-based design tasks with continuous variables... more In this paper, we focus on techniques for constraint-based design tasks with continuous variables in dynamic environments. We show how design spaces can be explored within an intelligent CAD system using a dynamic constraint satisfaction framework and a conflict resolution paradigm. Navigation between different design spaces is controlled by assumptions the designer makes in situations of incomplete knowledge. These assumptions
Design tasks in structural engineering have always involved the use of constraints to formulate d... more Design tasks in structural engineering have always involved the use of constraints to formulate design requirements. Most existing algorithms for constraint satisfaction require input consisting of binary constraints on variables that have discrete values. Such restrictions limit their use in structural engineering since typical structural design tasks involve discrete and numerical variables. This paper provides an approach for decision support
We introduce and apply a new classification strategy we call computerized consensus diagnosis (CC... more We introduce and apply a new classification strategy we call computerized consensus diagnosis (CCD). Its purpose is to provide robust, reliable classification of biomedical data. The strategy involves the cross-validated training of seven/ classifiers of diverse conceptual and methodological origin on the same data, and appropriately combining their outcomes. The strategy is tested on proton magnetic resonance spectra of human thyroid biopsies, which are successfully allocated to normal or carcinoma classes. We used Linear Discriminant Analysis, a Neural Net-based method, and Genetic Programming as independent classifiers on two spectral regions, and chose the median of the six classification outcomes as the consensus. This procedure yielded 100% specificity and 100% sensitivity on the training sets, and 100% specificity and 98% sensitivity on samples of known malignancy in the test sets.
Journal of Pharmaceutical and Biomedical Analysis, 2010
Bile acids, phospholipids, and cholesterol are the major lipid components in human bile. The comp... more Bile acids, phospholipids, and cholesterol are the major lipid components in human bile. The composition of bile is altered in various cholestatic diseases, and determining such alterations will be of great clinical importance in understanding the pathophysiology of these diseases. A robust method for the simultaneous quantification of major biliary lipids -glycine-conjugated bile acids (GCBAs), taurine-conjugated bile acids (TCBAs), total bile acids (TBAs) and choline-containing phospholipids (choline-PLs) has been devised using 1 H NMR spectroscopy. Bile samples were obtained from patients with various hepatopancreatobiliary diseases (n = 10) during an endoscopic retrograde cholangiopancreatography (ERCP) examination. Peak areas of metabolite-signals of interest were obtained simultaneously by deconvoluting the experimental spectrum, making the present method robust. GCBAs and TCBAs have been quantified using the peak areas of their characteristic methylene (CH 2 ) signals resonating at 3.73 and 3.07 ppm, whereas TBA and choline-PLs were quantified using their methyl (CH 3 ) and trimethylammonium (-N + (CH 3 ) 3 ) signals resonating at 0.65 and 3.22 ppm respectively. The present method was compared with an NMR-based literature method (which involves dissolving bile in DMSO), and a good correlation was observed between the two methods with regression coefficients -0.97, 0.99, 0.98 and 0.93 for GCBAs, TCBAs, TBAs, and choline-PLs respectively. This method has the potential to be extended to in vivo applications for the simultaneous quantification of various biliary lipids non-invasively.
A unique procedure for the biosynthesis and subsequent isolation of a series of specifically deut... more A unique procedure for the biosynthesis and subsequent isolation of a series of specifically deuteriated cis,cis-octadeca-6,9-dienoic acids has been developed. An auxotroph of Tetrahymena, which lacks ..delta..9 and ..delta..12 desaturase activity, is supplemented with specifically deuteriated oleic acid and converts it to the corresponding deuteriated cis,cis-octadeca-6,9-dienoic acid, 18:2/sup ..delta..6,9/. The deuteriated fatty acid is subsequently isolated by argentation chromatography and
Material microstructure is a significant determinant of the tensile stress at which materials fai... more Material microstructure is a significant determinant of the tensile stress at which materials fail. Using a high-energy laser to drive shocks in thin slabs, we have explored the role material microstructure plays on the spall strength of high-purity and alloyed aluminum at strain rates of (2-7.5)×106 s-1. Slabs of pure recrystallized Al and recrystallized or cold worked Al+3 wt % Mg were shock driven using the Z-Beamlet Laser at Sandia National Laboratories. Velocity interferometer measurements determined the spall strength of the materials, and postshot target analysis explored the microscopic fracture morphology. We observed the greatest spall strength for large-grained, recrystallized high-purity aluminum, with the dominant failure mode being ductile and transgranular. We observe for the first time at these strain rates fracture features for a fine-grained Al+3 wt % Mg that were a combination of brittle intergranular and ductile transgranular fracture types. Postshot analysis of target cross sections and hydrocode simulations indicate that this mixed-mode failure results from spall dynamics occurring on spatial scales on the order of the grain size. Differences in spall strength between these Al samples were experimentally significant and correlate with the damage morphologies observed.
This study examined the effects of 10 days of buthionine sulfoximine (BSO) treatment on in vitro ... more This study examined the effects of 10 days of buthionine sulfoximine (BSO) treatment on in vitro contractility and sarcoplasmic reticulum calcium pump (SERCA) expression and function in adult (AD; 6-8 months old) and middle aged (MA; 14-17 months old) rat diaphragm in both the basal state and following fatiguing stimulation. BSO treatment reduced the cellular concentrations of free glutathione (GSH) by >95% and oxidized glutathione (GSSG) by >80% in both age cohorts. GSH content in AD Control diaphragm was 32% higher (P < 0.01) than in MA Control, with no differences in GSSG. The ratio of GSH:GSSG, an indicator of cellular oxidative state, was 34.6 ± 7.4 in MA Control, 52.5 ± 10.1 in AD Control, 10.6 ± 1.7 in MA BSO, and 9.5 ± 1.1 in AD BSO (BSO vs. Control,…
International Journal for Numerical and Analytical Methods in Geomechanics, 1992
In this note the accuracy of the elastic standard 4-node plane-strain finite element is investiga... more In this note the accuracy of the elastic standard 4-node plane-strain finite element is investigated by comparing numerically calculated eigenvalues of the element stiffness matrix to those according to higherorder algebraic approximations. From this study it may be concluded that the 'hourglass' eigenmodes are the only inaccurate ones. For selective reduced numerical integration the hourglass eigenvalues may be expected to be of the order of 1/2 to 2/3 of the analytical values. *Professor. 'Lecturer. 'Professor.
Ground-based and Airborne Instrumentation for Astronomy III, 2010
SPHERE is a second generation instrument for the Very Large Telescope (VLT) which will aim at dir... more SPHERE is a second generation instrument for the Very Large Telescope (VLT) which will aim at directly detecting the intrinsic flux of young giant exoplanets thanks to a dedicated extreme adaptive optics system and coronagraphs. Exoplanet detection in the near-infrared will be performed in parallel with an integral field spectrograph and a differential imager, IRDIS. IRDIS main mode for exoplanet
ABSTRACT In Part I, eigenvalues and eigenmodes of typical plane element stiffness matrices were s... more ABSTRACT In Part I, eigenvalues and eigenmodes of typical plane element stiffness matrices were separated and traced. This has important implications for the viability of new elements (presence of zero energy modes) and integrability of dynamic equations (critical time steps). In this part of the paper, similar techniques are applied to well-known solid element stiffness matrices, and to some new ones.
Proceedings of the fifth ACM conference on Hypertext - HYPERTEXT '93, 1993
We describe the organization and implementation of the Knowledge Weasel (KW) Hypermedia Annotatio... more We describe the organization and implementation of the Knowledge Weasel (KW) Hypermedia Annotation System which we are using to explore knowledge structuring by collaborative annotation. Knowledge Weasel incorporates many useful features: a common record format for representing annotations in different media for uniform access; dynamic user control of the presentation of annotations as a navigational aid global navigation using queries
Background: The aim was to develop robust classi®ers to analyse magnetic resonance spectroscopy (... more Background: The aim was to develop robust classi®ers to analyse magnetic resonance spectroscopy (MRS) data of ®ne-needle aspirates taken from breast tumours. The resulting data could provide computerized, classi®cation-based diagnosis and prognostic indicators.
Canadian Journal of Physiology and Pharmacology, 2015
In this study, we sought to determine whether differences in cellular properties associated with ... more In this study, we sought to determine whether differences in cellular properties associated with energy homeostasis could explain the higher incidence of work-related myalgia in trapezius (TRAP) compared with extensor carpi radialis brevis (ECRB). Tissue samples were obtained from the ECRB (n = 19) and TRAP (n = 17) of healthy males and females (age 27.9 ± 2.2 and 28.1 ± 1.5 years, respectively; mean ± SE) and analyzed for properties involved in both ATP supply and utilization. The concentration of ATP and the maximal activities of creatine phosphokinase, phosphorylase, and phosphofructokinase were higher (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05) in ECRB than TRAP. Succinic dehydrogenase, citrate synthase, and cytochrome c oxidase were not different between muscles. The ECRB also displayed a higher concentration of Na(+)-K(+)-ATPase and greater sarcoplasmic reticulum Ca(2+) release and uptake. No differences existed between muscles for either monocarboxylate transporters or glucose transporters. It is concluded that the potentials for high-energy phosphate transfer, glycogenolysis, glycolysis, and excitation-contraction coupling are higher in ECRB than TRAP. Histochemical measurements indicated that the muscle differences are, in part, related to differing amounts of type II tissue. Depending on the task demands, the TRAP may experience a greater metabolic and excitation-contraction coupling strain than the ECRB given the differences observed.
Sample8 (3 mm3 of hlstopathologlcally normal (n = 15) and carclnomatous tissue (n = 15) were obta... more Sample8 (3 mm3 of hlstopathologlcally normal (n = 15) and carclnomatous tissue (n = 15) were obtalned from colectomy speclmens and examined by 'H MRS. A combination of oneand two-dlmenslonal spectra, obtalned with approprlate acquisition and processing parameters, provlde multiple dlagnostlc parameters allowlng the distlnctlon between normal and carcinomatous tlssue. The dlagnostlc parameters Include rosonances from choline, chollne-based, and other metabo-Iltes, cell surface fucosylatlon, and altered llpld profiles. Tlssues hlstopathologlcally classifled as normal, while remalnlng distlnct from the mallgnant spectral profile, were found to flt Into two categorles, one of whlch had some of the spectral characteristics of malignancy. These results indicate that 'H MRS Identlfles abnormal colorectal mucosa, whlch Is not morphologically manlfest Such abnormalities have been reported prevlously to exlst In premallgnant colorectal tissue by monocllonai antlbody studies. Collectlvely, these results suggest that a cilnlcal study of colorectal blopsles by lH MRS could provlde support for the use of MRS as an adjunct to current pathologlcal procedures.
Magnetic Resonance Materials in Physics, Biology and Medicine, 2009
Objective There are no specific biomarkers available for the definitive diagnosis of pancreatic c... more Objective There are no specific biomarkers available for the definitive diagnosis of pancreatic cancer. Analysis of d-glucuronic acid (GlcUA) in bile could be valuable in this regard. Materials and methods Bile samples obtained from patients with pancreatic cancer (n = 4), chronic pancreatitis (n = 3) and control patients with biliary obstruction (n = 10) were analyzed by 1 H NMR spectroscopy. GlcUA was quantified from the peak area of the α-1 CH signal (at 5.24 ppm) obtained by deconvolution. Results GlcUA was detected in human bile by one-dimensional 1 H NMR and two-dimensional 1 H-1 H COSY and TOCSY experiments. Quantification of GlcUA was achieved by measuring the peak area of the α-1 CH signal using CPMG experiment, and the quantities of GlcUA were calibrated to account for the attenuation due to T 2 relaxation. GlcUA was observed at elevated levels in bile samples obtained from pancreatic cancer patients, whereas it was either absent or found in negligible amounts in control and chronic pancreatitis patients. The reason for the presence of elevated levels of GlcUA could be the hydrolysis of biliary bilirubin diglucuronide by β-glucuronidase, released excessively from pancreatic tissue during the course of malignancy.
This paper is concerned with bringing together the topics of uncertainty evaluation using a Monte... more This paper is concerned with bringing together the topics of uncertainty evaluation using a Monte Carlo method, distributed computing for data parallel applications and pseudo-random number generation. A study of a measurement system to estimate the absolute thermodynamic temperatures of two high-temperature blackbodies by measuring the ratios of their spectral radiances is used to illustrate the application of these topics. The uncertainties associated with the estimates of the temperatures are evaluated and used to inform the experimental realization of the system. The difficulties associated with determining model sensitivity coefficients, and demonstrating whether a linearization of the model is adequate, are avoided by using a Monte Carlo method as an approach to uncertainty evaluation. A distributed computing system is used to undertake the Monte Carlo calculation because the computational effort required to evaluate the measurement model can be significant. In order to ensure that the results provided by a Monte Carlo method implemented on a distributed computing system are reliable, consideration is given to the approach to generating pseudo-random numbers, which constitutes a key component of the Monte Carlo procedure.
The utility of (1)H MR spectroscopy in detecting chronic cholestasis has been investigated. The a... more The utility of (1)H MR spectroscopy in detecting chronic cholestasis has been investigated. The amide proton region of the (1)H MR spectrum of human bile plays a major role in differentiating cholestatic (Ch) patterns from the normal ones. Bile obtained from normal bile ducts contains both taurine and glycine conjugates of bile acids--cholic acid (CA), chenodeoxycholic acid (CDCA), and deoxycholic acid (DCA). Absence of a glycine-conjugated bile acid glycochenodeoxycholic acid (GCDCA) has been observed in bile samples obtained from primary sclerosing cholangitis (PSC) patients. A total of 32 patients with various hepatobiliary diseases were included in the study. Twenty-one patients had PSC and 11 had normal cholangiograms. One PSC patient was excluded from the study because of a bad spectrum. Seventeen out of the 20 PSC patients showed an absence of GCDCA in their (1)H MR spectrum of bile. Six of the 11 reference patients with normal cholangiogram also showed spectra similar to those of PSC, indicating the possibility of cholestasis. DQF-COSY and TOCSY experiments performed on bile samples from PSC patients also revealed absence of phosphatidylcholine (PC) in some of the bile samples, suggesting possible damage to the cholangiocytes by the toxic bile. These observations suggest that analysis of human bile by (1)H MRS could be of value in the diagnosis of chronic Ch liver disorders.
An inertial-confinement-fusion (ICF) concept using two 60-MA Z pinches to drive a cylindrical hoh... more An inertial-confinement-fusion (ICF) concept using two 60-MA Z pinches to drive a cylindrical hohlraum to 220 eV has been recently proposed. The first capsule implosions relevant to this concept have been performed at the same physical scale with a lower 20-MA current, yielding a 70+/-5 eV capsule drive. The capsule shell shape implies a polar radiation symmetry, the first high-accuracy measurement of this type in a pulsed-power-driven ICF configuration, within a factor of 1.6-4 of that required for scaling to ignition. The convergence ratio of 14-21 is to date the highest in any pulsed-power ICF system.
ABSTR ACT: Metabolomics is a relatively new technique that is gaining importance very rapidly. MR... more ABSTR ACT: Metabolomics is a relatively new technique that is gaining importance very rapidly. MRS-based metabolomics, in particular, is becoming a useful tool in the study of body fluids, tissue biopsies and whole organisms. Advances in analytical techniques and data analysis methods have opened a new opportunity for such technology to contribute in the field of diagnostics. In the MRS approach to the diagnosis of disease, it is important that the analysis utilizes all the essential information in the spectra, is robust, and is non-subjective. Although some of the data analytic methods widely used in chemical and biological sciences are sketched, a more extensive discussion is given of a 5-stage Statistical Classification Strategy. This proposes powerful feature selection methods, based on, for example, genetic algorithms and novel projection techniques. The applications of MRSbased metabolomics in breast cancer, prostate cancer, colorectal cancer, pancreatic cancer, hepatobiliary cancers, gastric cancer, and brain cancer have been reviewed. While the majority of these applications relate to body fluids and tissue biopsies, some in vivo applications have also been included. It should be emphasized that the number of subjects studied must be sufficiently large to ensure a robust diagnostic classification. Before MRS-based metabolomics can become a widely used clinical tool, however, certain challenges need to be overcome. These include manufacturing user-friendly commercial instruments with all the essential features, and educating physicians and medical technologists in the acquisition, analysis, and interpretation of metabolomics data.
Solid State Lasers for Application to Inertial Confinement Fusion: Second Annual International Conference, 1997
ABSTRACT An exhaustive set of Beamlet and Nova laser system simulations were performed over a wid... more ABSTRACT An exhaustive set of Beamlet and Nova laser system simulations were performed over a wide range of power levels in order to gain understanding about the statistical trends in Nova and Beamlet&#39;s experimental data sets, and to provide critical validation of propagation tools and design `rules&#39; applied to the 192-arm National Ignition Facility at Lawrence Livermore National Laboratory.
Journal of clinical oncology : official journal of the American Society of Clinical Oncology, Jan 10, 2014
To document the rate and outcome of trastuzumab-associated cardiac dysfunction in patients follow... more To document the rate and outcome of trastuzumab-associated cardiac dysfunction in patients following 1 or 2 years of adjuvant therapy. The Herceptin Adjuvant (HERA) trial is a three-arm, randomized trial comparing 2 years or 1 year of trastuzumab with observation in 5,102 patients with human epidermal growth factor receptor 2 (HER2) -positive early-stage breast cancer. Cardiac function was closely monitored. Eligible patients had left ventricular ejection fraction (LVEF) ≥ 55% at study entry following neoadjuvant chemotherapy with or without radiotherapy. This 8-year median follow-up analysis considered patients randomly assigned to 2 years or 1 year of trastuzumab or observation. The as-treated safety population for 2 years of trastuzumab (n = 1,673), 1 year of trastuzumab (n = 1,682), and observation (n = 1,744) is reported. Cardiac adverse events leading to discontinuation of trastuzumab occurred in 9.4% of patients in the 2-year arm and 5.2% of patients in the 1-year arm. Cardia...
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