Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment, 2006
In conventional intravascular ultrasound (IVUS)-based three-dimensional (3D) reconstruction of hu... more In conventional intravascular ultrasound (IVUS)-based three-dimensional (3D) reconstruction of human coronary arteries, IVUS images are arranged linearly generating a straight vessel volume. However, with this approach real vessel curvature is neglected. To overcome this limitation an imaging method was developed based on integration of IVUS and biplane coronary angiography (BCA). In 17 coronary arteries from nine patients, IVUS and BCA were performed. From each angiographic projection, a single end-diastolic frame was selected and in each frame the IVUS catheter was interactively detected for the extraction of 3D catheter path. Ultrasound data was obtained with a sheath-based catheter and recorded on S-VHS videotape. S-VHS data was digitized and lumen and media-adventitia contours were semi-automatically detected in end-diastolic IVUS images. Each pair of contours was aligned perpendicularly to the catheter path and rotated in space by implementing an algorithm based on Frenet-Serret rules. Lumen and media-adventitia contours were interpolated through generation of intermediate contours creating a real 3D lumen and vessel volume, respectively. The absolute orientation of the reconstructed lumen was determined by back-projecting it onto both angiographic planes and comparing the projected lumen with the actual angiographic lumen. In conclusion, our method is capable of performing rapid and accurate 3D reconstruction of human coronary arteries in vivo. This technique can be utilized for reliable plaque morphometric, geometrical and hemodynamic analyses. r
Objective: High levels of insulin-like growth factor-I (IGF-I) are associated with an increased c... more Objective: High levels of insulin-like growth factor-I (IGF-I) are associated with an increased cancer risk and reduce risk of diabetes and coronary heart disease. We investigated associations of diet in childhood, in particular energy intake, with the IGF system in adulthood to determine if IGF-I -disease associations could be linked to early nutrition. Design: Retrospective cohort study. Setting: Sixteen survey centres in England and Scotland that originally participated in the Carnegie (Boyd Orr) Survey of Diet and Health in Pre-War Britain, 1937-1939. Subjects: Seven hundred and twenty-eight participants (679 with complete data) in the Boyd Orr cohort. Methods: Participants were originally surveyed between 1937 and 1939 (at median age 5.8 years; inter-quartile range: 2.9-9.6) and were followed up for 65 years. Dietary exposure in childhood was assessed from 7-day household food inventories. Outcomes are expressed as regression coefficients for the change in IGF per standard deviation increased childhood nutrient or food intake, as derived from levels of household consumption. Results: In fully-adjusted models, energy-rich family diets in childhood were not associated with IGF-I (regression coefficient: 0.9 ng/ml; 95% confidence interval (CI): À1.8, 3.7), IGF-II, IGF binding proteins (IGFBP)-2 or IGFBP-3 in adulthood. IGF-I was associated inversely with childhood family-diets high in milk (À2.5 ng/ml; À5.1, 0.1; P ¼ 0.05) and positively with vegetable-rich diets (3.5 ng/ml; 0.9, 6.1; P ¼ 0.009). IGF-I was not associated with family diets rich in protein, carbohydrates, fats, calcium, meat or fruit. IGF-II, IGFBP-2 and IGFBP-3 were not related to childhood family diet. Conclusions: This study suggests that energy-rich family diets in childhood do not program the IGF system in adulthood. As childhood diet was based on household consumption, however, measurement error may obscure individual-level diet-IGF associations. The associations of milk-and vegetable-rich family diets in childhood with IGF-I could be chance findings, but nevertheless are consistent with recent publications and warrant further investigation.
HLA class-1 expression has been investigated by biochemical methods in 14 Burkitt lymphoma (BL) c... more HLA class-1 expression has been investigated by biochemical methods in 14 Burkitt lymphoma (BL) cell lines and the corresponding Epstein-Barr virus (EBV)-transformed lymphoblastoid cell lines (LCL) derived from the same individuals. Selective down-regulation of one or more HLA class-1 specificities was demonstrated in 9 out of 14 BL lines. The defect was restricted to a single HLA-A allele in 3 of the lines (BL29, BL72, WW-1-BL). Four lines (BL28, BL37, BL41 and Jijoye M13) showed down-regulation of both HLA-A and -C alleles, and one (BL36) failed to express one HLA-C allele. Only one BL line (WW-2-BL) had lost one HLA-A and one HLA-B allele. The allele-specific defects were mainly detected in cell lines that had maintained the phenotypic characteristics of the original tumor. Expression of B-cell activation markers and the EBV-encoded nuclear antigen (EBNA)-2 correlated with up-regulation of the Cw4 allele in the P79 subline of the BL line Jijoye. Treatment with gamma-interferon (IFN) resulted in full or partial reversion of the HLA class-1 defects in some of the cases but had no significant effect in others. This was not due to a cell-line-related unresponsiveness to IFN, nor did it reflect an allele-specific mode of regulation because the same allele could respond differently in different cell lines. The data suggest that defective expression of HLA class-1 antigens, which appears to be more prevalent for alleles within the HLA-A and -C loci, is a common feature of BL cell lines. Different regulatory mechanisms appear to be involved.
This paper introduces the notions of approximate and optimal approximate zero polynomial of a pol... more This paper introduces the notions of approximate and optimal approximate zero polynomial of a polynomial matrix by deploying recent results on the approximate GCD of a set of polynomials [1] and the exterior algebra [4] representation of polynomial matrices. The results provide a new definition for the "approximate", or "almost" zeros of polynomial matrices and provide the means for computing the distance from non-coprimeness of a polynomial matrix. The computational framework is expressed as a distance problem in a projective space. The general framework defined for polynomial matrices provides a new characterization of approximate zeros and decoupling zeros [2], [4] of linear systems and a process leading to computation of their optimal versions. The use of restriction pencils provides the means for defining the distance of state feedback (output injection) orbits from uncontrollable (unobservable) families of systems, as well as the invariant versions of the "approximate decoupling polynomials".
The concept of "strong stability" of LTI systems has been introduced in a recent paper . This is ... more The concept of "strong stability" of LTI systems has been introduced in a recent paper . This is a stronger notion of stability compared to alternative definitions (e.g. stability in the sense of Lyapunov, asymptotic stability), which allows the analysis and design of control systems with no overshooting response in the phase-space for arbitrary initial conditions. Here, after a brief review of "strong stability" and its relation with other stability notions, we introduce the problem of "strong stabilisation". It is shown that strong stabilisation under dynamic and static output feedback are, in a certain sense, equivalent problems. Thus, we turn our attention to static strong stabilization problems under state-feedback, output injection and output feedback. After developing a number of preliminary results, we give a geometric interpretation of the problem in terms of the intersection of an affine hyperplane and the interior of an open convex cone. A solution to the problem is finally obtained via Linear Matrix Inequalities, along with the complete parametrisation of the optimal solution set of strongly stabilising matrices. The paper concludes by establishing simple (sufficient) strong stabilisation conditions using a linear programming (LP) methodology and by extending our results to robust strong stabilisation problems under two separate model uncertainty descriptions.
Recent investigations revealed that the 9p arm and 17q arm of human chromosomes harbour tumour su... more Recent investigations revealed that the 9p arm and 17q arm of human chromosomes harbour tumour suppressor genes (TSGs) with an important role in multistage carcinogenesis. At the 9p arm is located the pl6 (MTSl) TSG and probably others with an effect on various human tumours such as acute lymphoblastic leukaemia, bladder cancer, gliomas, malignant mesotheliomas, melanomas and non-small cell lung carcinomas. In addition, the 17q arm harbours BRCAl TSG which is responsrble for approximately 80% of the familial breast/ovarian cancer cases. In order to investigate the implication of these novel TSGs in the development of laryngeal cancer we performed a loss of heterozygosity (LOH) analysis with 10 polymorphic microsatellite markers (three at the 17q arm surrounding the BRCAl region and seven at the 9p arm). Fourteen of the 17 (82%) tumours exhibited deletions at 9p. The highest incidence of LGH (6/13, 46%) was found for the marker D9S1.57 at 9~22. One sample exhibited deletion of all the informative markers tested indicating deletion of the complete 9p arm. No homozygous deletions were found. LOH at the 17q arm near the BRCAl locus was found in 6 (35%) among 17 specimens. The results of this study indicate that allelic deletions at 9p are frequent in the development of laryngeal tumours. The highest incidence of LOH was found for the marker D9S157 which is near, but distinct from the location of p16 (MTSl) tumour suppressor gene, indicating the presence of multiple tumour suppressor genes within this chromosomal region. In addition, BRCAI TSG is implicated in the development of laryngeal tumours.
For realizing proactive Location-based Services it is necessary to automatically detect when the ... more For realizing proactive Location-based Services it is necessary to automatically detect when the mobile device enters or leaves certain geographical zones. Assuming terminal-based positioning like GPS, in a rudimentary approach this can be realized by continuous operation of the GPS receiver, where the generated position fixes are always checked against the zone definition. However, as GPS is very energy-consuming, this will lead to a quick battery drain and thus to a bad user experience. As a possible solution, this paper presents a novel technique which dynamically switches on and off the GPS receiver. The goal is to keep the GPS receiver off as long as possible in order to save energy, while still being able to detect the entering or leaving of a zone. The basic idea is to compare the device's current GSM measurements with the ones taken the last time the GPS was switched on. If, based on that comparison, it can be ruled out that the zone has been entered or left, the GPS receiver may remain switched off. For comparing GSM readings, the classical Common Base Station indicator is extended by considering multiple samples and incorporating values of Received Signal Strength. The paper presents results based on simulated as well as real test data, which underline the validity of the method.
Analytical solutions are developed for harmonic wave propagation in an axially or laterally oscil... more Analytical solutions are developed for harmonic wave propagation in an axially or laterally oscillating pile embedded in homogeneous soil and excited at the top. Pilesoil interaction is realistically represented through a dynamic Winkler model, the springs and dashpots of which are given values based on results of finite element analyses with the soil treated as a linear hysteretic continuum. Closed form expressions are derived for the phase velocities of the generated waves; these are compared with characteristic phase velocities in rods and beams subjected to compressionextension (axial) and flexural (lateral) vibrations. The role of radiation and material damping is elucidated; it is shown that the presence of such damping radically changes the nature of wave propagation, especially in lateral oscillations where an upward propagating (reflected) wave is generated even in a semi-infinite head-loaded pile. Solutions are then developed for the phase differences between pile displacements at various depths. For most piles such differences are not significant and waves emanate nearly simultaneously from the periphery of an oscillating pile. This conclusion is useful in analysing dynamic pile to pile interaction, the consequences of which are shown in this Paper.
Context: Taller individuals with longer legs have a higher risk of cancer but a lower risk of cor... more Context: Taller individuals with longer legs have a higher risk of cancer but a lower risk of coronary heart disease.
Compte-rendu du débat thématique des Rencontres du RÉSEAU écobâtir P r i n t e m p s 2 0 1 2 • 1 ... more Compte-rendu du débat thématique des Rencontres du RÉSEAU écobâtir P r i n t e m p s 2 0 1 2 • 1 er , 2 e t 3 j u i n • L e G a b i o n à E m b r u n ( ) La précarité énergétique RÉSEAU écobâtir • http://reseau-ecobatir.org SAMEDI 2 JUIN 2012, APRÈS-MIDI 3 Débat thématique 3 De l'approche énergétique comme outil de réappropriation du logement social par ses usagers 4 Energétique précarité 7 Précarité énergétique et intensité sociale 8 Le Lambda de la Quechua Sommaire Rencontres RÉSEAU écobâtir • Embrun • Juin 2012
Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment, 2006
In conventional intravascular ultrasound (IVUS)-based three-dimensional (3D) reconstruction of hu... more In conventional intravascular ultrasound (IVUS)-based three-dimensional (3D) reconstruction of human coronary arteries, IVUS images are arranged linearly generating a straight vessel volume. However, with this approach real vessel curvature is neglected. To overcome this limitation an imaging method was developed based on integration of IVUS and biplane coronary angiography (BCA). In 17 coronary arteries from nine patients, IVUS and BCA were performed. From each angiographic projection, a single end-diastolic frame was selected and in each frame the IVUS catheter was interactively detected for the extraction of 3D catheter path. Ultrasound data was obtained with a sheath-based catheter and recorded on S-VHS videotape. S-VHS data was digitized and lumen and media-adventitia contours were semi-automatically detected in end-diastolic IVUS images. Each pair of contours was aligned perpendicularly to the catheter path and rotated in space by implementing an algorithm based on Frenet-Serret rules. Lumen and media-adventitia contours were interpolated through generation of intermediate contours creating a real 3D lumen and vessel volume, respectively. The absolute orientation of the reconstructed lumen was determined by back-projecting it onto both angiographic planes and comparing the projected lumen with the actual angiographic lumen. In conclusion, our method is capable of performing rapid and accurate 3D reconstruction of human coronary arteries in vivo. This technique can be utilized for reliable plaque morphometric, geometrical and hemodynamic analyses. r
Objective: High levels of insulin-like growth factor-I (IGF-I) are associated with an increased c... more Objective: High levels of insulin-like growth factor-I (IGF-I) are associated with an increased cancer risk and reduce risk of diabetes and coronary heart disease. We investigated associations of diet in childhood, in particular energy intake, with the IGF system in adulthood to determine if IGF-I -disease associations could be linked to early nutrition. Design: Retrospective cohort study. Setting: Sixteen survey centres in England and Scotland that originally participated in the Carnegie (Boyd Orr) Survey of Diet and Health in Pre-War Britain, 1937-1939. Subjects: Seven hundred and twenty-eight participants (679 with complete data) in the Boyd Orr cohort. Methods: Participants were originally surveyed between 1937 and 1939 (at median age 5.8 years; inter-quartile range: 2.9-9.6) and were followed up for 65 years. Dietary exposure in childhood was assessed from 7-day household food inventories. Outcomes are expressed as regression coefficients for the change in IGF per standard deviation increased childhood nutrient or food intake, as derived from levels of household consumption. Results: In fully-adjusted models, energy-rich family diets in childhood were not associated with IGF-I (regression coefficient: 0.9 ng/ml; 95% confidence interval (CI): À1.8, 3.7), IGF-II, IGF binding proteins (IGFBP)-2 or IGFBP-3 in adulthood. IGF-I was associated inversely with childhood family-diets high in milk (À2.5 ng/ml; À5.1, 0.1; P ¼ 0.05) and positively with vegetable-rich diets (3.5 ng/ml; 0.9, 6.1; P ¼ 0.009). IGF-I was not associated with family diets rich in protein, carbohydrates, fats, calcium, meat or fruit. IGF-II, IGFBP-2 and IGFBP-3 were not related to childhood family diet. Conclusions: This study suggests that energy-rich family diets in childhood do not program the IGF system in adulthood. As childhood diet was based on household consumption, however, measurement error may obscure individual-level diet-IGF associations. The associations of milk-and vegetable-rich family diets in childhood with IGF-I could be chance findings, but nevertheless are consistent with recent publications and warrant further investigation.
HLA class-1 expression has been investigated by biochemical methods in 14 Burkitt lymphoma (BL) c... more HLA class-1 expression has been investigated by biochemical methods in 14 Burkitt lymphoma (BL) cell lines and the corresponding Epstein-Barr virus (EBV)-transformed lymphoblastoid cell lines (LCL) derived from the same individuals. Selective down-regulation of one or more HLA class-1 specificities was demonstrated in 9 out of 14 BL lines. The defect was restricted to a single HLA-A allele in 3 of the lines (BL29, BL72, WW-1-BL). Four lines (BL28, BL37, BL41 and Jijoye M13) showed down-regulation of both HLA-A and -C alleles, and one (BL36) failed to express one HLA-C allele. Only one BL line (WW-2-BL) had lost one HLA-A and one HLA-B allele. The allele-specific defects were mainly detected in cell lines that had maintained the phenotypic characteristics of the original tumor. Expression of B-cell activation markers and the EBV-encoded nuclear antigen (EBNA)-2 correlated with up-regulation of the Cw4 allele in the P79 subline of the BL line Jijoye. Treatment with gamma-interferon (IFN) resulted in full or partial reversion of the HLA class-1 defects in some of the cases but had no significant effect in others. This was not due to a cell-line-related unresponsiveness to IFN, nor did it reflect an allele-specific mode of regulation because the same allele could respond differently in different cell lines. The data suggest that defective expression of HLA class-1 antigens, which appears to be more prevalent for alleles within the HLA-A and -C loci, is a common feature of BL cell lines. Different regulatory mechanisms appear to be involved.
This paper introduces the notions of approximate and optimal approximate zero polynomial of a pol... more This paper introduces the notions of approximate and optimal approximate zero polynomial of a polynomial matrix by deploying recent results on the approximate GCD of a set of polynomials [1] and the exterior algebra [4] representation of polynomial matrices. The results provide a new definition for the "approximate", or "almost" zeros of polynomial matrices and provide the means for computing the distance from non-coprimeness of a polynomial matrix. The computational framework is expressed as a distance problem in a projective space. The general framework defined for polynomial matrices provides a new characterization of approximate zeros and decoupling zeros [2], [4] of linear systems and a process leading to computation of their optimal versions. The use of restriction pencils provides the means for defining the distance of state feedback (output injection) orbits from uncontrollable (unobservable) families of systems, as well as the invariant versions of the "approximate decoupling polynomials".
The concept of "strong stability" of LTI systems has been introduced in a recent paper . This is ... more The concept of "strong stability" of LTI systems has been introduced in a recent paper . This is a stronger notion of stability compared to alternative definitions (e.g. stability in the sense of Lyapunov, asymptotic stability), which allows the analysis and design of control systems with no overshooting response in the phase-space for arbitrary initial conditions. Here, after a brief review of "strong stability" and its relation with other stability notions, we introduce the problem of "strong stabilisation". It is shown that strong stabilisation under dynamic and static output feedback are, in a certain sense, equivalent problems. Thus, we turn our attention to static strong stabilization problems under state-feedback, output injection and output feedback. After developing a number of preliminary results, we give a geometric interpretation of the problem in terms of the intersection of an affine hyperplane and the interior of an open convex cone. A solution to the problem is finally obtained via Linear Matrix Inequalities, along with the complete parametrisation of the optimal solution set of strongly stabilising matrices. The paper concludes by establishing simple (sufficient) strong stabilisation conditions using a linear programming (LP) methodology and by extending our results to robust strong stabilisation problems under two separate model uncertainty descriptions.
Recent investigations revealed that the 9p arm and 17q arm of human chromosomes harbour tumour su... more Recent investigations revealed that the 9p arm and 17q arm of human chromosomes harbour tumour suppressor genes (TSGs) with an important role in multistage carcinogenesis. At the 9p arm is located the pl6 (MTSl) TSG and probably others with an effect on various human tumours such as acute lymphoblastic leukaemia, bladder cancer, gliomas, malignant mesotheliomas, melanomas and non-small cell lung carcinomas. In addition, the 17q arm harbours BRCAl TSG which is responsrble for approximately 80% of the familial breast/ovarian cancer cases. In order to investigate the implication of these novel TSGs in the development of laryngeal cancer we performed a loss of heterozygosity (LOH) analysis with 10 polymorphic microsatellite markers (three at the 17q arm surrounding the BRCAl region and seven at the 9p arm). Fourteen of the 17 (82%) tumours exhibited deletions at 9p. The highest incidence of LGH (6/13, 46%) was found for the marker D9S1.57 at 9~22. One sample exhibited deletion of all the informative markers tested indicating deletion of the complete 9p arm. No homozygous deletions were found. LOH at the 17q arm near the BRCAl locus was found in 6 (35%) among 17 specimens. The results of this study indicate that allelic deletions at 9p are frequent in the development of laryngeal tumours. The highest incidence of LOH was found for the marker D9S157 which is near, but distinct from the location of p16 (MTSl) tumour suppressor gene, indicating the presence of multiple tumour suppressor genes within this chromosomal region. In addition, BRCAI TSG is implicated in the development of laryngeal tumours.
For realizing proactive Location-based Services it is necessary to automatically detect when the ... more For realizing proactive Location-based Services it is necessary to automatically detect when the mobile device enters or leaves certain geographical zones. Assuming terminal-based positioning like GPS, in a rudimentary approach this can be realized by continuous operation of the GPS receiver, where the generated position fixes are always checked against the zone definition. However, as GPS is very energy-consuming, this will lead to a quick battery drain and thus to a bad user experience. As a possible solution, this paper presents a novel technique which dynamically switches on and off the GPS receiver. The goal is to keep the GPS receiver off as long as possible in order to save energy, while still being able to detect the entering or leaving of a zone. The basic idea is to compare the device's current GSM measurements with the ones taken the last time the GPS was switched on. If, based on that comparison, it can be ruled out that the zone has been entered or left, the GPS receiver may remain switched off. For comparing GSM readings, the classical Common Base Station indicator is extended by considering multiple samples and incorporating values of Received Signal Strength. The paper presents results based on simulated as well as real test data, which underline the validity of the method.
Analytical solutions are developed for harmonic wave propagation in an axially or laterally oscil... more Analytical solutions are developed for harmonic wave propagation in an axially or laterally oscillating pile embedded in homogeneous soil and excited at the top. Pilesoil interaction is realistically represented through a dynamic Winkler model, the springs and dashpots of which are given values based on results of finite element analyses with the soil treated as a linear hysteretic continuum. Closed form expressions are derived for the phase velocities of the generated waves; these are compared with characteristic phase velocities in rods and beams subjected to compressionextension (axial) and flexural (lateral) vibrations. The role of radiation and material damping is elucidated; it is shown that the presence of such damping radically changes the nature of wave propagation, especially in lateral oscillations where an upward propagating (reflected) wave is generated even in a semi-infinite head-loaded pile. Solutions are then developed for the phase differences between pile displacements at various depths. For most piles such differences are not significant and waves emanate nearly simultaneously from the periphery of an oscillating pile. This conclusion is useful in analysing dynamic pile to pile interaction, the consequences of which are shown in this Paper.
Context: Taller individuals with longer legs have a higher risk of cancer but a lower risk of cor... more Context: Taller individuals with longer legs have a higher risk of cancer but a lower risk of coronary heart disease.
Compte-rendu du débat thématique des Rencontres du RÉSEAU écobâtir P r i n t e m p s 2 0 1 2 • 1 ... more Compte-rendu du débat thématique des Rencontres du RÉSEAU écobâtir P r i n t e m p s 2 0 1 2 • 1 er , 2 e t 3 j u i n • L e G a b i o n à E m b r u n ( ) La précarité énergétique RÉSEAU écobâtir • http://reseau-ecobatir.org SAMEDI 2 JUIN 2012, APRÈS-MIDI 3 Débat thématique 3 De l'approche énergétique comme outil de réappropriation du logement social par ses usagers 4 Energétique précarité 7 Précarité énergétique et intensité sociale 8 Le Lambda de la Quechua Sommaire Rencontres RÉSEAU écobâtir • Embrun • Juin 2012
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